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Browse our blog to learn more about thin film and conformal coating processes, material, and application. Find out more about HZO and how our solutions can help your market.

Polymer Glass Transition Temperature - Material Properties, Impact

Polymer glass transition temperature (Tg) refers to the temperature at which an amorphous polymer transitions from a glassy, rigid state to a rubbery, flexible state...

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What is Coefficient of Linear Expansion? Formula, Units & More

Temperature affects the behavior of materials, causing them to expand or contract. However, not all materials respond to temperature variations in the same way. Some materials,..

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Diagram of thermal conductivity

What is Thermal Conductivity? Explanation, Measurement, Uses

Thermal conductivity is a fundamental concept in heat transfer and is crucial in multiple industries and scientific disciplines. It refers to the ability of a material to conduct..

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Index of refraction illustrated through glass

What is the Index of Refraction? Measurement, Definition & More

Understanding how light travels through different mediums is essential in optics. One invaluable optical property is the index of refraction. This measurement quantifies how much..

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testing for tensile strength at yield

Tensile Strength at Yield - Testing, Standards, Specs, Material

The ability to accurately predict the behavior of coating materials under tension is crucial in ensuring the integrity and reliability of electronic components. This includes..

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Elongation at Break - Definition, Testing, Material Selection

Elongation at break is a key mechanical property that measures the deformation capacity of a material before it eventually snaps or breaks, providing insights into the material's..

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Diagram of Young's Modulus

Young's Modulus of Polymers - Measurement, Calculation

Young's Modulus is an important property, allowing engineers to select coating materials based on their desired stiffness. Understanding and manipulating the elastic Modulus of..

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Water Vapor Transmission Rate - Standards, Testing, Material

In the world of electronics, moisture control is of utmost importance. High water vapor transmission rate (WVTR) can pose significant risks to sensitive electronic devices. When..

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transparent polymer coating on a piece of glass

Transparent Polymers - Applications, Material Selection

Transparent polymers offer optical clarity and the ability to transmit light. With various applications across various industries, these polymers have gained popularity for their..

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Biocompatible Coatings - Coating Techniques, Applications, More

Biocompatible coatings seamlessly integrate with the human body, offering benefits through their ability to promote healing and prevent adverse reactions. They can improve patient..

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Dissipation Factor - Definition, Measurement, Variables

Dielectric materials are crucial in various industries and applications, serving as insulators, substrates, or capacitors. One important characteristic often evaluated in..

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Volume Resistivity - Definition, Measurement, Product Design

Whether designing circuit boards or protecting electrical components, knowledge of the volume resistivity of coating materials plays a pivotal role in creating efficient and..

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UL94 Coating Material - Testing Method, Material Selection

Fire safety compliance is an indispensable aspect across various industries. One crucial benchmark in fire safety compliance is UL94, a widely recognized standard for flammability..

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Yield Elongation of a material

Elongation Yield: Overview, Unit of Measure, Data and Testing

Elongation yield refers to the maximum amount of deformation a material can undergo before it experiences a permanent change in shape or size. This property is fundamental in..

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Difference Between Water Resistant, Repellent, & Proof

We all see references to waterproof, water-resistant, and water-repellant devices being thrown around on electronic products. The big question is: What’s the difference? There are..

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Top Electronics Manufacturing Industry Publications

If you work in the electronics manufacturing industry, you are likely plagued with information overload, whether you are an engineer, purchasing professional, or business-oriented..

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ADAS Design and Validation for the Real World - Automotive Coatings

Advanced driver assistance systems (ADAS) continue to expand in features and functionalities. Standard offerings may include adaptive cruise control, park assist, blind-spot..

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Traditional Waterproofing vs. Conformal Coating Waterproofing

Traditional Waterproofing vs. Conformal Coating Waterproofing These days, we take our electronic devices everywhere and expect them to be waterproof. People want to take photos at..

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Parylene Conformal Coatings - Parylene Conformality Explained

Parylene (p-polyxylylene) conformal coatings are unique due to their capacity to be polymerized and deposited by the chemical vapor deposition (CVD) method onto surfaces near room..

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What is Parylene Coating Used For? Is it Right For My Project?

For decades, Parylene coatings, including Parylene C, Parylene F (VT-4), and Parylene N, have been trusted to enhance the reliability and performance of printed circuit boards and..

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Dielectric Constant of Insulator Materials: Formula, Table of Values

Depending on their formulated ingredients and molecular structures, thin film coatings may be electrically conductive, insulative, or semiconductive. Insulative coatings serve..

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What is the Dielectric Strength Formula? Testing, Table of Values

Although thin film coatings serve many purposes, providing dielectric isolation and electrical insulation is one of the essential functions. Dielectric strength is an important..

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Arc Resistance - Concepts and Testing Explained

Insulating materials such as Teflon, plastic, rubber, ceramic, or glass ensure products function properly and safely. However, no insulator is perfect. These materials still..

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Conformal Coating for Drones - Which is Best?

As technology advances, so do the capabilities of drones, which are available in various sizes, weights, and shapes. The technological advancements in drone specifications,..

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Parylene masking equipment

Parylene Masking - General Concepts Explained

Conformal coatings are an excellent way to increase the reliability of electronic components in harsh environments. However, this protection can be too much of a good thing..

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Parylene Chemical Resistance Properties - Overview

Choosing a conformal coating can be a complex decision that entails understanding the environment your electronic products will be operating in and taking stock of the threats to..

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Parylene Biocompatibility Properties

As a long-proven biocompatible material, Parylene conforms to ISO-10993 and is USP Class VI implantable material. Its properties make it ideal for biological and medical..

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Parylene N Properties Explained Datasheet PDF Download

Parylene is the generic name for poly-para-xylylenes. These conformal coatings come in several varieties, including Parylene C, Parylene F (VT-4), and Parylene N. Parylene..

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How to Make Your Lithium-ion Battery Design More Sustainable

A recent report from “Markets and Markets” revealed that experts expect the battery recycling market to grow to $23.2 billion by 2025, at a CAGR of 6.1% from 2020-2025. This..

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Improving CGM Electronics Designs with Medical Coatings

A vital issue for continuous glucose monitor development is design and reliability engineering. CGM systems, however, will encounter environments that can jeopardize electronics..

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Developing Health Wearable Devices That Work in the Real World

Smart wearable medical device designers must create flexible, lightweight, low-profile, comfortable electronic products that enable constant, real-time data transmission. The data..

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Parylene chemical formula on a dollar bill

How Much Does Parylene Coating Cost? - All Things Considered

Parylene coatings are known for robust protection from liquids, corrosion, chemicals, and strong electrical activity at a fraction of the thickness of alternative coatings, such..

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Engineer Looking at Coating With Equipment

Parylene C Datasheet (PDF Download) - Properties Explained

Parylene conformal coatings come in various types, including Parylene C, Parylene N, and Parylene F (VT-4), with decades of trusted performance in critical industries and..

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How to Remove Conformal Coating - Which Method is Best?

Conformal coatings are polymeric films applied directly to PCBAs and electronic components to provide a barrier layer of protection from the environment in which they operate...

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Engineer removing Parylene coating

Parylene Coating Removal - Methods & Explanation

In the last blog post in our removing conformal coating series, we discussed removing conventional conformal coatings, such as polyurethane, acrylic, epoxy, and silicone, from..

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Definitive Guide to Conformal Coating Application Methods

Conformal coating materials, including acrylics, epoxies, urethanes, silicones, and Parylene, introduce different benefits, drawbacks, and challenges to any project. Because there..

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How to Choose a Nanocoating Material

As engineers, it is our job to bring products to life and ensure they operate as expected until the end of the product life cycle. Therefore, a large part of our job is to prevent..

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NEMA vs IP Ratings Explained

Once upon a time, computers only sat perched on desktops, but that is no longer the case. Deployed in harsh industrial, medical, automotive, and consumer household environments,..

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Overview of the Plasma Nanocoating Process

Nanocoatings, thin films measured at the nanolevel, serve numerous purposes. But for many product design engineers, the ability to safeguard electronics with protection..

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How To: A Wearable Device Design That Consumers Actually Want

Wearable devices provide insight and convenience to consumers through activity tracking and biometric data that they can easily access through a wearable app. But many wearable..

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What is Corrosion & Does It Ruin Electronics? How to Remove It?

Imagine the following scenario: You are washing the dishes, listening to music on your smartphone when suddenly the unthinkable happens – the phone that was nestled safely in your..

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Conformal Coating Thermal Conductivity - Prevent Overheating

Design engineers have more to worry about these days than ever before. The demand for smaller electronic devices with more capabilities is exponentially growing, causing..

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IoT - Coating Consistency is Key

IoT sensors aggregate and send data to IoT dashboards, simplifying critical, complex decisions quickly. One key area where this is particularly true is the utilization of sensor..

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Polyurethane Conformal Coatings - Benefits & Applications

Conformal coatings are polymeric materials applied to a PCB to improve device reliability. These films protect electronics from environmental threats, including humidity, liquids,..

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6 Common Conformal Coating Defects & Their Solutions

When we say that a chain is only as strong as its weakest link, we aren’t talking about polymer chains – we’re talking about conformal coating defects. Regardless of the type, a..

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Conformal Coating vs Potting/Encapsulation - The Pros & Cons

As the world of electronics continues to grow and evolve, printed circuit board assemblies (PCBAs) find their way into more and more products and industries. Whether you create..

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Coating engineer inspecting parylene film on pcb

Parylene - Different Types & Properties Explained

Parylene is a chemical compound applied to substrates using chemical vapor deposition (CVD). Because Parylene coating deposits onto the surface molecule by molecule, it forms a..

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Solving Weather & Water Challenges For Smart Farms

It’s a Small World, After All The world’s population is projected to reach 8.5 billion by 2030, an unprecedented increase approaching fast. This looming surge will compound our..

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Designing a Waterproof Product With IP Ratings

The Big Picture: Manufacturers determine IP ratings, not an impartial group. Although these rating systems are useful for comparison purposes, they are not the panacea for rating..

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Mallory McGuinness-Hickey

Mallory is a veteran writer with over a decade of writing experience and has spent over four years at HZO learning about coating technology from the best minds in the industry. Professionally, Mallory is especially interested in the process of problem-solving and watching how the engineering team develops solutions that ensure business requirements are met. In her free time, you can find Mallory walking her dog Ebbie, fueling up on coffee, watching the Simpsons, and referencing the Simpsons. All of Mallory’s blogs are reviewed for accuracy before publication.

Recent Posts

Polymer Glass Transition Temperature - Material Properties, Impact

September 21, 2023 / by Mallory McGuinness-Hickey posted in Protection Capabilities, Coating Properties

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Polymer glass transition temperature (Tg) refers to the temperature at which an amorphous polymer transitions from a glassy, rigid state to a rubbery, flexible state. Understanding the polymer glass transition temperature is crucial for various industries, including engineering and manufacturing. The Tg provides valuable insights into a polymer's behavior, such as its processing, mechanical, thermal, and overall performance characteristics.

The polymer's structure, molecular weight, chemical composition, and branching influence the glass transition temperature. The Tg affects properties like stiffness, impact resistance, thermal stability, and transparency. Design engineers can optimize material selection, processing conditions, and performance requirements by understanding how the Tg relates to polymer structure.

Basics of Glass Transition

The glass transition is a phenomenon that occurs in amorphous polymers where the material changes from a rigid and brittle state to a softer and more flexible state when certain temperature conditions are met.

Several factors can affect the glass transition temperature (Tg) of polymers:

  • Molecular weight and chain length: Polymers with higher molecular weights and longer chain lengths tend to have higher Tg values.
  • Chemical structure and composition: Different chemical structures and compositions can result in variations in Tg values.
  • Presence of plasticizers or additives: Plasticizers and additives can lower the Tg of polymers, making them more flexible and less brittle.
  • Crystallinity or amorphous nature of the polymer: Amorphous polymers generally have lower Tg values than crystalline polymers.

Influence of Glass Transition Temperature on Polymer Properties

A polymer's glass transition temperature (Tg) plays a crucial role in determining its properties and performance. This temperature marks the transition from the glassy state to the rubbery state, where the polymer undergoes significant changes in its physical and mechanical behavior.

Impact on mechanical properties

The glass transition temperature has a profound effect on various mechanical properties of polymers, such as:

  • Tensile strength: The Tg of a polymer can influence its tensile strength. Polymers with a higher Tg tend to have higher tensile strength, as the increased molecular mobility at elevated temperatures allows for better alignment and bonding.
  • Elastic modulus: The Tg also affects the elastic modulus, which refers to a material's ability to resist deformation. Polymers with a higher Tg typically exhibit a higher elastic modulus, indicating greater stiffness and rigidity.
  • Impact resistance: The Tg can impact the impact resistance of polymers. As the Tg increases, the polymer becomes more brittle and prone to fracture upon impact. On the other hand, polymers with lower Tg values exhibit better impact resistance and toughness.

Effect on thermal behavior

The glass transition temperature has significant implications for the thermal behavior of polymers:

  • Melting temperature and thermal conductivity: The Tg influences the melting temperature of a polymer. Polymers with higher Tg values generally have higher melting temperatures. Additionally, a higher Tg can result in lower thermal conductivity, which affects the material's ability to transfer heat.
  • Heat resistance and aging: The Tg indicates a polymer's heat resistance. Polymers with high Tg values exhibit better heat resistance and are less prone to degradation at elevated temperatures. Furthermore, understanding the Tg is crucial for predicting the long-term aging behavior of a polymer in various environmental conditions.

Temperature-Dependent Polymer Properties

Temperature plays a crucial role in determining the properties of polymers. As the temperature changes, various characteristics of polymers undergo significant transformations. Understanding the temperature-dependent behavior of polymers is essential for a wide range of applications, from material selection to manufacturing processes.

Changes in Polymer Properties with Temperature Variations

When exposed to different temperatures, polymers exhibit distinct alterations in their properties. These variations include changes in mechanical strength, electrical conductivity, chemical resistance, and dimensional stability. For example, as the temperature rises, the mechanical strength of a polymer tends to decrease due to increased molecular motion.

Relationship Between Glass Transition Temperature and Other Temperature-Dependent Properties

Glass transition temperature has a relationship with other temperature-dependent properties, including:

  • Specific heat capacity: The glass transition temperature of a polymer is closely related to its specific heat capacity, which is the amount of heat required to raise the temperature of a unit mass of the material by a certain degree. Understanding this relationship is essential for predicting polymers' heat absorption and release capabilities at different temperatures.
  • Coefficient of thermal expansion: The coefficient of thermal expansion measures the extent to which a material expands or contracts when subjected to temperature changes. The glass transition temperature considerably influences the coefficient of thermal expansion of polymers. Higher glass transition temperatures generally result in lower coefficients, indicating reduced dimensional change with temperature.
  • Viscosity and flow behavior: As the temperature varies, polymers experience viscosity and flow behavior changes. Polymers act as rigid solids with high viscosity at temperatures below the glass transition temperature. However, as the temperature surpasses the glass transition temperature, polymers transition into a more flexible state, exhibiting lower viscosity and increased flow characteristics.

Measurement and Determination of Values

Obtaining accurate glass transition temperature data is essential. Several experimental techniques may be employed for measurement, including:

  • Differential Scanning Calorimetry (DSC): DSC is a widely used technique that measures the heat transfer in a sample as it goes through a glass transition. It provides information about the glass transition temperature and the enthalpy of transition.
  • Dynamic Mechanical Analysis (DMA): DMA measures the mechanical properties of a sample as a function of temperature or frequency. It can provide information about the glass transition temperature by observing changes in the sample's modulus, damping, and storage modulus.
  • Thermomechanical Analysis (TMA): TMA measures the dimensional changes of a sample as a function of temperature or time. It can determine the glass transition temperature by monitoring changes in the sample's dimensions.
  • Fourier Transform Infrared Spectroscopy (FTIR): FTIR measures a sample's absorption of infrared light. Analyzing the changes in the infrared spectra of the sample as a function of temperature can determine the glass transition temperature.

Factors influencing the accuracy and repeatability of glass transition temperature measurements

Several factors influence the accuracy and repeatability of glass transition temperature measurements, such as:

  • Heating and cooling rates: The rate at which the sample is heated or cooled can affect the observed glass transition temperature. Different heating and cooling rates can lead to variations in the measured value.
  • Sample preparation and handling: How the sample is prepared and handled before the measurement can also impact the glass transition temperature. Contamination or improper handling can introduce errors.
  • Physical state of the polymer (solid, liquid, or semi-solid): The physical state of the polymer can affect the glass transition temperature measurement. Different states can exhibit different glass transition temperatures.
  • Presence of impurities or additives: Impurities or additives present in the polymer can influence the observed glass transition temperature. These substances can alter the polymer's molecular structure and affect its behavior during the glass transition.

Role in material applications

The glass transition temperature influences the choice of polymers in various industries and applications, including:

  • Automotive and aerospace: The Tg of polymers used in automotive and aerospace applications is critical, as it determines their ability to withstand high-temperature environments and maintain dimensional stability.
  • Consumer goods and electronics: The Tg influences the selection of polymers for consumer goods and electronic devices. Polymers with suitable Tg values are chosen to ensure durability, impact resistance, and resistance to heat and aging.
  • Medical and healthcare sector: The Tg of polymers used in medical and healthcare applications is essential for ensuring biocompatibility, sterilizability, and resistance to various environmental factors.

This diverse range of applications highlights the glass transition temperature's crucial role in tailoring polymer properties to meet specific requirements. Contact our engineers if you need to choose a protective coating material with a particular glass transition temperature and require assistance or learn more about thin film protection capabilities, such as coefficient of linear expansion, thermal conductivity, or optical properties, such as refractive index or transparency.

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What is Coefficient of Linear Expansion? Formula, Units & More

September 21, 2023 / by Mallory McGuinness-Hickey posted in Coating Properties, Thin Film Applications

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Temperature affects the behavior of materials, causing them to expand or contract. However, not all materials respond to temperature variations in the same way. Some materials, like metals, tend to expand when heated, while others, like water, show a more complex behavior, with expansion occurring at specific temperatures.

Learn about other thermal coating properties, like thermal conductivity and glass transition temperature

This property is crucial in predicting how a material will respond to temperature changes. This coefficient, represented by the Greek letter alpha (α), describes how much a material expands per unit length for each degree of temperature rise. Understanding this concept helps engineers make accurate predictions and design structures that can withstand temperature fluctuations.

Formula for Calculating the Coefficient of Linear Expansion

The coefficient of linear expansion (α) can be calculated using the following formula:

α = ΔL / (L₀ × ΔT)

Where:

α is the coefficient of linear expansion

ΔL is the change in length

L₀ is the original length

ΔT is the change in temperature

Units used for expressing the coefficient

The coefficient of linear expansion is typically expressed in units of length per unit temperature, such as millimeters per degree Celsius (mm/°C) or inches per Fahrenheit (in/°F). These units emphasize the linear dimensions and temperature change required to induce a specific change in length. By using consistent units, scientists and engineers can easily compare and analyze the behavior of different materials.

Measurement and Units

Accurately measuring values is essential in understanding how materials respond to changes in temperature. Several experimental techniques are commonly employed to measure the coefficient of linear expansion. The most widely used method is known as the thermal expansion apparatus. This apparatus consists of a rod or sample material, which is heated or cooled while its length changes are recorded. By carefully analyzing the recorded data, researchers can calculate the coefficient of linear expansion for the material.

The interferometric method utilizes interference patterns created by light passing through a material. This technique accurately measures the changes in length resulting from thermal expansion.

Additionally, some advanced techniques like dilatometry, which involves measuring volume changes, and strain gauges, which record dimensional changes, are used for highly precise measurements of the coefficient of linear expansion.

Relationship between the Coefficient of Linear Expansion and Thermal Expansion

Thermal expansion refers to the increase in size or volume of a material as its temperature rises. This expansion occurs because heat causes the atoms and molecules within the material to move more rapidly, increasing their average spacing. As a result, the material takes up more space and expands.

Meanwhile, the coefficient of linear expansion represents the change in length per unit length per unit change in temperature.

The relationship between the coefficient of linear expansion (α) and thermal expansion can be expressed using the following formula:

Thermal expansion = coefficient of linear expansion × Original length × Change in temperature

This formula allows engineers to calculate a material's dimensions change when its temperature changes.

Factors Influencing the Coefficient 

Several factors can influence the coefficient of linear expansion in materials. These factors can affect how much a material expands or contracts when subjected to changes in temperature.

 Crystal Structure, Bonding Types, and Impurities

The crystal structure of a material heavily influences the coefficient of linear expansion. Different crystal structures can lead to variations in the coefficient. The type of bonding between atoms in a material can also affect its coefficient. For example, materials with stronger intermolecular forces tend to have lower coefficients, while those with weaker ones tend to have higher ones.

Impurities in a material can also impact its coefficient of linear expansion. Their presence can disrupt the regular arrangement of atoms, causing changes in the expansion behavior.

External Factors

External factors such as pressure, magnetic fields, and electric fields can also influence this value. Pressure can alter the arrangement of atoms in a material, affecting its expansion behavior. Similarly, magnetic fields and electric fields can cause changes in the alignment and movement of atoms, leading to variations in the coefficient.

Material Selection

This property is highly dependent on the material properties of a substance. Different materials exhibit different coefficients due to their unique structures and bonding arrangements. For example, materials with stronger intermolecular forces tend to have lower values because their particles are held tightly together, making them less likely to expand significantly with temperature changes.

Material properties such as elasticity, rigidity, and thermal conductivity also play a significant role in determining this value. Elastic materials can return to their original shape after being subjected to deformation caused by thermal expansion. On the other hand, rigid materials are less prone to significant expansion due to their stiffness and resistance to deformation.

Additionally, materials with high thermal conductivity tend to have higher values. High thermal conductivity allows for faster heat transfer, leading to greater expansion or contraction in response to temperature changes.

When dimensional stability is critical, materials with low coefficients are preferred to minimize undesired expansions or contractions. On the other hand, materials with higher coefficients may be utilized in applications where controlled expansion is desired.

Engineers can make informed decisions regarding material selection, product design, and manufacturing processes by understanding how different materials expand or contract with temperature changes. This knowledge helps create efficient and durable structures, products, and systems. If you are looking for a coating material to suit your application needs, please contact our engineers to discuss DFM. Or, learn more about thin film protection capabilities, such as optical properties like transparency and index of refraction.

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What is Thermal Conductivity? Explanation, Measurement, Uses

September 21, 2023 / by Mallory McGuinness-Hickey posted in Protection Capabilities, Coating Properties

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Thermal conductivity is a fundamental concept in heat transfer and is crucial in multiple industries and scientific disciplines. It refers to the ability of a material to conduct heat or the rate at which heat transfers through a substance. Understanding this property is essential for designing efficient thermal systems, optimizing energy usage, and ensuring the safety and performance of various materials and products.

Learn about other thermal coating properties like glass transition temperature and linear coefficient of expansion.  

Fundamentals of Heat

Understanding heat and its relationship to thermal conductivity is essential in grasping the concepts of heat transfer. Heat, in its simplest form, transfers energy from one object to another due to temperature differences.

Temperature gradient plays a significant role. A temperature gradient refers to the difference in temperature between two points in a material or between two adjacent materials. Heat transfer occurs when there is a temperature gradient, with heat flowing from regions of higher temperature to regions of lower temperature.

This phenomenon is driven by the basic principle of nature - the tendency of a system to seek equilibrium. When there is a temperature difference, the system will naturally attempt to balance the temperatures, leading to heat transfer and thermal conductivity.

The Physics Behind Thermal Conductivity

Thermal conductivity is a fascinating concept deeply rooted in the fundamental principles of physics. At its core, thermal conductivity is defined as the ability of a material to conduct heat. This ability is determined by various physical factors that govern the flow of heat energy.

The mechanisms of heat conduction can explain this property at the molecular level. Heat conduction occurs when a temperature is different between two points in a material. In simple terms, it is the movement of heat energy from higher-temperature to lower-temperature regions.

One of the fundamental relayed principles is the concept of thermal resistivity. This refers to a material's resistance to the flow of heat. Materials with lower thermal resistivity have higher thermal conductivity, allowing heat to be transferred more easily.

Another essential principle is the role of atomic and molecular interactions. Heat energy is transferred through these interactions as atoms or molecules collide and exchange kinetic energy. A material's structure and arrangement of atoms or molecules can greatly impact its values.

Measurement Techniques

Measurement techniques are crucial in providing accurate data to understand thermal conductivity. Various experimental methods have been developed to measure thermal conductivity, each with advantages and limitations.

Overview of Experimental Methods

Experimental methods for measuring involve subjecting the material to controlled thermal conditions and observing the resulting heat transfer. These methods can be broadly classified into steady-state and transient techniques.

  • Steady-State Heat Flow: This method involves establishing a steady-state heat flux through the material and measuring the temperature gradient. Knowing the sample's dimensions and the temperature difference, the value can be calculated using Fourier's Law of heat conduction.
  • Transient Hot Wire Method: A thin wire with a known value is placed in contact with the material in this technique. A constant heat flux is applied to the wire, and the temperature rise is measured. By analyzing the rate of temperature change, thermal conductivity can be determined.
  • Laser Flash Analysis: Laser flash analysis is commonly used to measure thermal conductivity in solids. This method applies a short pulse of laser light to one end of the sample, creating an instantaneous temperature rise. The temperature decay is then measured and analyzed to calculate the value.

Non-Destructive Testing Techniques

Non-destructive testing techniques are commonly employed when measurements must be taken on finished products or structures without altering their integrity. These methods offer convenience and allow for thermal conductivity measurements in real-world applications.

Some non-destructive testing techniques commonly used for measuring thermal conductivity include infrared thermography, ultrasound, and thermal wave analysis. These techniques utilize the principles of heat transfer and allow for non-intrusive measurement of thermal conductivity in various materials.

Applications of Thermal Conductivity

The concept of thermal conductivity is essential in designing and optimizing thermal insulation materials to reduce heat loss or gain. It is also pivotal in developing efficient heat exchangers, such as those used in HVAC systems, refrigeration units, and power plants.

Additionally, it is a key factor in determining the performance and efficiency of electronic devices, such as computer processors and power electronics. Optimizing this value helps dissipate heat generated by these devices, preventing overheating and ensuring longevity.

Here are some examples of the wide-ranging applications of thermal conductivity:

  • Designing heat sinks for electronic devices: This property helps dissipate heat generated by components, ensuring optimal performance and preventing overheating.
  • Energy recovery systems: Energy recovery systems aim to capture and utilize waste heat generated by industrial processes. By efficiently transferring heat, it enables the conversion of waste heat into usable energy, reducing energy consumption and costs.
  • Enhancing thermal management in engineering applications: The property helps design and optimize cooling systems, ensuring efficient heat dissipation and preventing equipment failure due to overheating.

Due to the importance of this material property, selecting a protective coating material with the most suitable value is paramount. Please get in touch with us if you are a design engineer and have questions about protective coatings for electronic components. Otherwise, learn more about protective coating protection properties, such as optical properties like refractive index and transparency.

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What is the Index of Refraction? Measurement, Definition & More

September 20, 2023 / by Mallory McGuinness-Hickey posted in Protection Capabilities, Coating Properties

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Understanding how light travels through different mediums is essential in optics. One invaluable optical property is the index of refraction. This measurement quantifies how much a ray of light bends when it passes from one medium to another. The index of refraction plays a crucial role in understanding the behavior of light in various optical devices and phenomena.

Read more about transparent polymers.

Definition of the Index of Refraction

The index of refraction is a numerical value that represents the ratio between the speed of light in a vacuum and the speed of light in a given material. It determines how much the direction of light changes as it passes through a medium, such as air, water, or glass.

The higher the value, the slower light travels through the material, resulting in a greater bending or refraction of the light ray. This is due to the interaction between the electromagnetic waves of light and the charged particles within the medium.

Measurement Methods 

Several methods exist to accurately measure the index of refraction. Here are some widely used techniques:

  • Using refractometers: Refractometers are optical devices that determine the index of refraction by measuring the angle at which a light ray bends when passing through a sample material.
  • Employing mathematical models based on the speed of light: This involves calculations using mathematical equations that incorporate the speed of light in a vacuum and the speed of light in a particular medium. These models consider variables such as wavelength and frequency to derive the index value accurately.
  • Snell's Law: Snell's Law is a fundamental principle that relates the angles of incidence and refraction between two mediums. By measuring these angles and applying Snell's Law, the index of refraction can be determined.
  • Speed of Light: Another way to measure the index of refraction is by comparing the speed of light in a vacuum to the speed of light in a particular medium. This method requires precise measurements of the speed of light and the refractive properties of the medium.
  • Critical Angle: When light travels from a medium with a higher refractive index to a medium with a lower refractive index, it can reach a critical angle at which total internal reflection occurs. By measuring this critical angle, the index of refraction can be determined.
  • Dispersion: Dispersion refers to the phenomenon where different wavelengths of light (colors) refract at different angles when passing through a medium. By studying the dispersion of light, scientists can derive the index of refraction for each wavelength, creating a refractive index spectrum.

These measurement techniques allow engineers to understand better how light interacts with matter.

Refractive Index and the Speed of Light

Light, as we know, travels at an incredible speed through space. However, when it enters a medium, such as glass or water, its speed is significantly reduced due to the phenomenon of the index of refraction. Understanding the relationship between the index of refraction and the speed of light is crucial in various scientific and practical applications.

Why light travels slower in mediums with higher refractive indices:

When light passes through a medium, it interacts with the atoms and molecules in that medium. These particles cause the light to slow down as it continuously gets absorbed and re-emitted. The higher the refractive index of the medium, the more significant this effect becomes, resulting in slower light propagation.

Effects of different materials on the speed of light propagation:

Materials with higher refractive indices, such as diamond or glass, slow down light considerably. In contrast, materials with lower refractive indices, such as air or vacuum, allow light to travel at its maximum speed. This variance in speed is why light bends or changes direction when passing from one medium to another.

Index of Refraction and Product Design

The index of refraction has numerous practical applications in various fields. One application is the design of optical fibers, lenses, microscopes, telescopes, and other devices. By manipulating the path of light through different materials with different refractive indices, engineers can achieve desired outcomes such as focusing, magnification, and dispersion.

Additionally, understanding the behavior of light as it interacts with different materials allows engineers to develop and improve optical instruments. These instruments, ranging from cameras to spectrometers, rely on the principles of the index of refraction to function effectively.

If you are working on an application that requires a protective coating with certain optical properties, HZO might be able to help. Please contact us to speak to an engineer. Or, if you are more interested in learning about protective coating capabilities, read about thermal conductivity, linear coefficient of expansion, or glass transition temperature.

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Tensile Strength at Yield - Testing, Standards, Specs, Material

September 19, 2023 / by Mallory McGuinness-Hickey posted in Protection Capabilities, Coating Properties, Thin Film Applications

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The ability to accurately predict the behavior of coating materials under tension is crucial in ensuring the integrity and reliability of electronic components. This includes studying different materials' deformation and failure mechanisms when subjected to a tensile load. One key parameter that is used to quantify the ability of a material to withstand such loads is its tensile strength at yield.

What is Tensile Strength at Yield?

Tensile Strength at Yield indicates a material's ability to withstand loads and forces during its lifetime, making it crucial for designing structures and components that can endure various stresses. It is a vital measurement in numerous disciplines, such as engineering, manufacturing, aerospace, and automotive.

When a material is subjected to a tensile load, it experiences stress and undergoes deformation. The stress-strain curve, representing the relationship between the applied stress and resulting strain, provides valuable insights into the material's behavior. This curve can determine the ultimate tensile strength, the maximum stress the material can withstand before failure occurs.

The yield point is a critical parameter in studying tensile strength at yield. It refers to the point on the stress-strain curve where a significant increase in strain occurs with minimal or no increase in stress. The tensile strength at yield is the stress level at this point and represents the maximum stress a material can withstand without undergoing permanent deformation.

During the deformation process, materials can exhibit different types of behavior. Elastic deformation occurs when a material returns to its original shape upon removal of the load, while plastic deformation occurs when the material undergoes permanent changes in shape. Understanding the concepts of elastic and plastic deformation is essential in analyzing a material's behavior under tension.

Testing Methods, Equipment, and Standards Used for Measurement 

Due to the importance of this mechanical material property, obtaining accurate Tensile Strength at Yield data is critical. Accurately measuring it requires appropriate testing methods, equipment, and adherence to specific standards. The most commonly used technique is the tensile test, where a sample material is subjected to an increasing axial load until it reaches its yield point. Sophisticated equipment, such as universal testing machines, performs these tests and obtains reliable measurements. Standard organizations, such as ASTM International, provide guidelines and standards for conducting these tests, ensuring consistency and comparability of results.

Standards and Specifications 

Standards and specifications are crucial in ensuring the accuracy, reliability, and consistency of measurements. National and international organizations have established various standards to regulate this critical characteristic of materials.

Similarly, numerous national and international standards have been developed to guide the measurement and characterization of tensile strength at yield. These standards outline the specific testing methods, equipment, and conditions to ensure accurate and comparable results across different laboratories and industries.

The American Society for Testing and Materials (ASTM), International Organization for Standardization (ISO), and Deutsches Institut für Normung (DIN) are among the leading organizations that have established widely recognized standards for tensile strength at yield. Compliance with these standards is essential in ensuring test data's uniformity, reliability, and compatibility.

What Influences Tensile Strength at Yield?

Material composition plays a crucial role in determining values. Different elements and their proportions can significantly affect the mechanical properties of a material, including its yield strength. For example, increasing the amount of carbon in certain materials can enhance tensile strength at yield.

The microstructure of a material also plays a vital role in determining this value. Factors such as grain size, phase distribution, and dislocation density can impact the material's ability to withstand deformation before yielding.

Coating Material Selection and Design Factors

Because this mechanical property is crucial in determining various structures and products' overall reliability and safety, it should be closely considered during material selection. Every industry and application has unique requirements for choosing a coating material. Engineers must account for environmental conditions, load-bearing capacity, and durability requirements. They can select appropriate materials to meet the desired performance and safety standards by evaluating the tensile strength at yield requirements specific to each industry. A summary of requirements for particular applications is below.

Evaluating Tensile Strength at Yield requirements for different industries

  • Aerospace: In the aerospace industry, where extreme conditions and rigorous performance requirements exist, coating materials with exceptional tensile strength at yield are crucial. This property ensures aircraft components' structural integrity and safety, such as wings and fuselage, under immense stress during flight.
  • Automotive: This property is vital in automotive engineering as it affects vehicle structural stability. Manufacturers and designers prioritize coating materials with optimal values to enhance passenger safety and overall vehicle performance.
  • Consumer products: From household appliances to sports equipment, consumer products are designed to withstand daily usage and potential impacts. Tensile strength at yield is vital in ensuring that these products can withstand the forces they are subjected to without deforming or failing.

Importance in Coating Material Selection

Tensile strength at yield is a critical mechanical property used in coating material selection. It provides valuable information about the protective coating material's ability to withstand applied forces without permanent deformation. If a protective coating were to break, it could allow corrosives and contaminants to destroy electronic components, causing failure.

Design engineers rely on this property to evaluate and compare different coating materials, ensuring their suitability for specific applications. If you are designing an electronic component and need help determining which coating material is best for your product, please contact our engineers, or read additional information on thin film coating properties.

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Elongation at Break - Definition, Testing, Material Selection

September 19, 2023 / by Mallory McGuinness-Hickey posted in Protection Capabilities, Coating Properties, Thin Film Applications

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Elongation at break is a key mechanical property that measures the deformation capacity of a material before it eventually snaps or breaks, providing insights into the material's behavior and performance. This crucial measurement is closely related to tensile strength, which determines a material's ability to withstand pulling forces without breaking.

The longer the elongation at break, the greater the material's flexibility and ductility. It represents how much a material can stretch or elongate under tension before reaching its breaking point.

In metals, elongation at break showcases malleability and ensures they can withstand deformation without fracturing easily. Plastics with higher elongation at break are more capable of enduring stress and strain without undergoing permanent damage. Understanding the importance of elongation at break helps select the right materials for diverse applications, ensuring optimal performance and durability.

Testing Methods for Elongation at Break

Elongation at break is a key indicator of a material's ability to stretch before reaching its breaking point, so accurate data is vital for material selection. To precisely determine this value, various testing methods are employed.

When conducting tests, manufacturing and quality control considerations play an essential role. These considerations include:

  • Ensuring that sampling is representative of the material being tested.
  • Using appropriate and calibrated testing equipment to obtain accurate measurements.
  • Following standardized testing procedures to maintain consistency.

By considering these factors, manufacturers can ensure the reliability and integrity of their testing results, which are critical for maintaining consistent material properties. Two methods of testing are described below.

Tensile Testing

Tensile testing involves subjecting a material sample to tension until it fractures. The sample is held between two clamps and pulled in opposite directions until it breaks. The amount of elongation before fracture is recorded and used to calculate the final value.

Elongation Testing

Elongation testing is another method utilized for measurement. Unlike tensile testing, this method focuses solely on measuring the elongation of a material sample without causing it to fracture. The sample is stretched until a specified strain value is achieved, and the resulting elongation is measured.

How to Calculate Elongation at Break

The elongation of the material sample at the point of fracture is measured by comparing the original length of the sample to its final length after fracturing. The percentage of elongation is then calculated by dividing the change in length by the original length and multiplying by 100.

Mechanical Properties and Plastic Deformation

Elongation at break is just one of the mechanical properties used to assess a material's performance. It is closely related to other properties like yield strength, resilience, and plastic deformation. Manufacturers often evaluate it alongside these properties to comprehensively understand a material's behavior.

For example, this property is a valuable measure of a material's ability to undergo plastic deformation. Plastic deformation refers to the permanent change in the shape of a material when subjected to stress. Materials with high elongation at break have greater plasticity and can undergo significant deformation without fracture.

Understanding the relationship between elongation at break and plastic deformation is crucial in various industrial applications. It allows engineers and manufacturers to select materials that can withstand the required stress and deformation without failure.

Consideration of Elongation at Break in Material Selection

Elongation at break is also widely used for material comparisons and benchmarking. By evaluating and selecting appropriate materials based on their desired levels of ductility and flexibility, industries can ensure that their products perform optimally under different operating conditions.

Materials with higher values are generally preferred in applications where the material needs to undergo extensive deformation without failure. On the other hand, materials with lower values may be desired for applications where high rigidity and resistance to deformation are required.

By considering elongation at break, engineers can make informed decisions regarding material selection and performance optimization, enhancing product reliability and customer satisfaction. If you are designing an electronic product that needs protective coatings and are having trouble identifying which material to choose, please contact our Applications Engineers for answers. Or if you are interested in learning more about thin film protective coating capabilities, such as such as elongation yield or Young's modulus of polymers, browse our site.

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Young's Modulus of Polymers - Measurement, Calculation

September 19, 2023 / by Mallory McGuinness-Hickey posted in Protection Capabilities, Coating Properties, Thin Film Applications

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Young's Modulus is an important property, allowing engineers to select coating materials based on their desired stiffness. Understanding and manipulating the elastic Modulus of polymers is crucial for applications where strength, flexibility, or a combination of both is required.

What is Young's Modulus of Polymers?

Young's Modulus, also known as the elastic Modulus, is a fundamental property that characterizes the mechanical behavior of a material. It quantifies the relationship between stress (force per unit area) and strain (deformation) when a material is subjected to an external force or load.

For polymers, Young's Modulus determines how much the material will stretch or compress in response to applied stress. It measures the rigidity of the polymer chain structure. When comparing Young's Modulus between polymers and other materials such as metals and ceramics, polymers typically have lower values. This is because polymers have a more flexible molecular structure, allowing them to undergo more significant elastic deformation under applied stress, in contrast to metals and ceramics with more rigid atomic structures.

Factors Influencing Young's Modulus 

Understanding the factors influencing Young's Modulus allows engineers to choose polymer materials with desired mechanical properties for specific applications. The following factors influence Young's Modulus of Polymers:

  • Molecular structure and chain flexibility: The arrangement and size of polymer chains determine their flexibility and, consequently, their Young's Modulus. Polymers with longer and more linear chains tend to have higher Young's Modulus values.
  • Degree of cross-linking and polymerization: Cross-linking refers to forming chemical bonds between polymer chains, increasing their rigidity and thus increasing Young's Modulus. Higher degrees of cross-linking result in higher Young's Modulus values.
  • Temperature and environmental conditions: Young's Modulus of polymers can vary with temperature and environmental conditions. The presence of moisture, for example, can affect the intermolecular forces within the polymer, leading to changes in Young's Modulus.

Measurement and Calculation of Young's Modulus

Measuring and calculating Young's Modulus is crucial to understanding the mechanical behavior of polymers. This value provides valuable insight into how a polymer will respond to applied stress and strain, making it essential in product design.

There are various experimental techniques used to measure Young's Modulus in polymers. These include:

  • Tensile testing and stress-strain curves: This technique involves subjecting a polymer sample to tension until it reaches its breaking point. The resulting stress-strain curve provides essential data for determining Young's Modulus.
  • Extensional methods: Uniaxial and biaxial extension tests measure Young's Modulus in specific directions. These methods help evaluate the anisotropic nature of polymers.
  • Other characterization techniques: Techniques such as nanoindentation and dynamic mechanical analysis can also be employed to measure Young's Modulus in polymers.

Calculation methods for Young's Modulus

Hooke's Law and stress-strain behavior interpretation play vital roles when calculating Young's Modulus:

  • Hooke's Law and its application to polymers: Hooke's Law states that the stress applied to a material is directly proportional to the strain it produces. This linear relationship allows for the calculation of Young's Modulus.
  • Interpretation of stress-strain behavior and determination of Modulus: By analyzing the stress-strain curve obtained from experimental data, the Modulus can be determined using mathematical methods tailored for polymers.

Role in Material Selection and Design

Young's Modulus helps engineers determine the stiffness and elasticity of polymers. Knowing Young's Modulus values allows them to select the appropriate material for a specific application. The higher the Young's Modulus, the stiffer the material will be, resulting in better resistance to deformation. This stiffness is crucial in applications where the polymer needs to withstand heavy loads or maintain its shape for a long time.

Some examples of how design engineers use Young's Modulus to select materials in different industries are listed below.

  • Automotive and aerospace applications: Young's Modulus is essential in designing components such as automotive body parts, airplane wings, and fuselages. It helps engineers ensure the materials can withstand the required forces and maintain their shape during operation.
  • Medical and healthcare applications: Young's Modulus is a consideration when developing medical devices, prosthetics, and implants. The Modulus ensures that the materials provide the necessary support, flexibility, and performance for patient safety and comfort.
  • Consumer goods and packaging: Young's Modulus comes into play in designing everyday products such as bottles, containers, and packaging materials. It helps determine the polymers' rigidity, flexibility, and impact resistance, ensuring they meet the specific requirements of the intended applications.
  • Industrial applications: Engineers can use the measure of stiffness or rigidity of a material to predict how polymers will behave under various conditions common in harsh industrial environments.

Relationship Between Young's Modulus and Product Performance and Durability

Because Young's Modulus directly affects a polymer's behavior under different loads and stresses, engineers can make informed decisions about material selection, design structures that can withstand specific loads, and ensure the safety and reliability of polymer-based products.

The knowledge of Young's Modulus allows for optimizing material properties, such as flexibility and strength, to meet the unique requirements of various industries. Whether in the automotive, aerospace, or medical field, an understanding of Young's Modulus enables the development of innovative solutions that are tailor-made for specific applications.

If you are an engineer involved in product design and would like guidance in selecting a suitable coating material for your application, please contact our team today. Alternatively, if you want to learn more about thin film properties, including elongation yield, elongation at break, or tensile strength at yield, browse our site. 

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Water Vapor Transmission Rate - Standards, Testing, Material

September 14, 2023 / by Mallory McGuinness-Hickey posted in Protection Capabilities, Coating Properties, Thin Film Applications

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In the world of electronics, moisture control is of utmost importance. High water vapor transmission rate (WVTR) can pose significant risks to sensitive electronic devices. When moisture enters electronic components, it can lead to various issues, including corrosion, short circuits, and malfunctioning. These risks can result in costly repairs, product failures, and even safety hazards.

Manufacturers continually strive to create smaller, faster, and more powerful electronics. However, these advancements also often make the devices more susceptible to moisture damage. Implementing effective moisture control measures during the design and manufacturing process is essential to ensure the longevity and reliability of electronic components.

Water vapor transmission refers to the movement of water vapor through a material or substance. The water vapor transmission rate is a pivotal property for moisture control, and as such, measuring and managing WVTR is a priority in many applications.  

 

Understanding Water Vapor, Transmission, and Vapor Transmission

Water vapor refers to the presence of water in a gaseous state. Under certain temperature and pressure conditions, water vapor can condense into liquid water.

Transmission refers to the movement of any substance, whether liquids, gases, or solids, from one side of a barrier to the other. This movement can occur through various means, such as diffusion, permeation, or evaporation. Vapor transmission, on the other hand, specifically relates to the movement of water vapor molecules through a barrier.

Vapor transmission plays a crucial role in moisture control. Without the ability for water vapor to move freely through materials, moisture can become trapped, leading to mold growth, structural damage, and product degradation. By allowing water vapor to escape, vapor transmission helps prevent excessive moisture buildup.

 

Factors affecting vapor transmission

Several factors influence the rate of vapor transmission. These include temperature, pressure, and humidity.

  • Temperature variations can affect the rate water molecules transition between vapor and liquid states. Higher temperatures generally increase the speed of vapor transmission.
  • Pressure differentials between the two sides of a barrier can also impact vapor transmission. In some cases, pressure differentials can hinder or enhance the movement of water vapor.
  • Humidity levels, which measure the amount of water vapor in the air, can greatly influence vapor transmission. Higher humidity often leads to higher vapor transmission rates, while lower humidity may restrict the movement of water vapor through materials.

 

Water Vapor Transmission Standards and Testing

The ASTM standards outline the procedures and techniques for conducting WVTR tests, ensuring consistency and accuracy across different laboratories and testing facilities. These standards provide guidelines on sample preparation, test conditions, and data analysis, allowing for reliable and comparable results.

Overview of Permeability Testing Methods and Techniques

Permeability testing refers to the evaluation of how easily water vapor can permeate through a material or film. Several methods are available to measure WVTR, including the gravimetric method, the desiccant method, and the electrical measurement method. Each method has its advantages and limitations, and the choice of method depends on factors such as the material being tested and the required accuracy. You can read more about these methods here

Importance of Accurate Testing for Reliable WVTR Results

Accurate testing determines a material's true water vapor transmission rate. By following ASTM standards and utilizing appropriate testing methods, manufacturers can ensure that their products meet the necessary performance requirements and provide optimal moisture control.

Learn about relevant standards such as Ingress Protection Standards and NEMA Ratings.

 

Film and Polymer Materials

Thin films play integral roles in creating effective moisture barrier systems. These materials are designed to prevent water vapor passage, thereby protecting products and structures from moisture damage.

Specific properties and characteristics become priorities when evaluating coating materials for moisture control. Engineers should consider the following:

  • Water vapor permeability: measures how easily water vapor can pass through a material. Lower permeability indicates better moisture resistance.
  • Tensile strength: the ability of the coating material to resist breaking or tearing under tension
  • Elongation at break: The maximum elongation or stretch a material can undergo before breaking. Higher elongation allows for flexibility and resistance to tearing.
  • Chemical resistance: the resistance of the material to chemical substances, preventing degradation and maintaining its moisture control properties
  • Transparency: In specific applications, it is essential for the polymer material to maintain transparency, allowing consumers to evaluate products visually.

If you need a coating material with a low water vapor transmission rate or have questions about choosing suitable materials, contact our Applications Engineers for a DFM consult. Or, you can learn more about protective thin film coating properties.

 

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Transparent Polymers - Applications, Material Selection

September 14, 2023 / by Mallory McGuinness-Hickey posted in Protection Capabilities, Coating Properties, Thin Film Applications, Value of Coatings

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Transparent polymers offer optical clarity and the ability to transmit light. With various applications across various industries, these polymers have gained popularity for their unique properties and versatility. Common transparent polymer types include acrylics, polycarbonates, parylenes, and polyurethanes. The molecular arrangement and morphology of transparent polymers play a crucial role in their transparency. Transparent polymers typically comprise transparent monomers that polymerize to form a solid material. A uniform and amorphous structure is of paramount importance in achieving optical clarity.

Read about refractive index, another optical property.

Applications of Transparent Polymers in Various Industries

Optics and Optical Devices

Transparent polymers are extensively used to produce lenses, optical fibers, LEDs, and displays. Due to their excellent optical clarity and refractive properties, these polymers contribute to the functionality and performance of these devices. They enable the transmission and manipulation of light, essential for achieving optimal performance in optics and optical devices.

Coatings and Films

Transparent polymer coatings and films are widely used for various applications, including protection, durability, and aesthetic enhancement. These coatings and films are applied on glass, metals, and electronics surfaces to provide a protective layer while maintaining transparency. Transparent polymer coatings and films also resist scratches, chemicals, and UV radiation.

Renewable Energy

They play a significant role in the fabrication and encapsulation of solar panels. They are transparent encapsulant materials that allow sunlight to be absorbed and transmitted to the photovoltaic cells within the solar panels. Transparent polymers help maximize the efficiency of solar panels by ensuring optimal light absorption and transmission.

Biomedical Applications

These polymers are extensively used in biomedical imaging, drug delivery systems, and tissue engineering. They enable clear visualization in imaging techniques and provide a platform for developing advanced drug delivery systems.

Displays and Electronics

Some of these polymers play a crucial role in the development of touch screens, flexible displays, and transparent conductive films used in electronics. They enable light transmission while providing electrical conductivity, making them essential components in the construction of displays and electronic devices. They also contribute to the production of sleek and high-performance electronic devices.

Coating Material Selection

Transparency, durability, and versatility make these polymers ideal for numerous applications. Transparent polymers enable technological advancements and enhanced user experiences from optical lenses to display screens. If you require this type of coating material for your product design and would like to speak to an engineer, HZO can help. Reach out today. Or, you can stay and read more about coating properties, including thermal conductivity, linear coefficient of expansion, and glass transition temperature

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Biocompatible Coatings - Coating Techniques, Applications, More

September 13, 2023 / by Mallory McGuinness-Hickey posted in Protection Capabilities, Coating Process, Coating Properties, Thin Film Applications

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Biocompatible coatings seamlessly integrate with the human body, offering benefits through their ability to promote healing and prevent adverse reactions. They can improve patient outcomes, reduce complications, and enhance device functionality. As such, biocompatible coatings have become an indispensable tool in various medical applications.

 

What is Biocompatibility, and What Affects the Biocompatibility of Coatings?

 

Biocompatibility refers to the ability of a material to function without causing any harmful effects to the living tissues or organs it comes into contact with.

Several factors influence the biocompatibility of coatings. One such factor is the material composition. The choice of materials used in a coating can significantly impact its compatibility with the human body. Additionally, the surface properties of the coating play a vital role in determining its biocompatibility. Roughness, porosity, and surface energy can affect how the coating interacts with biological tissues and fluids.

When it comes to achieving biocompatibility in coatings, there are key considerations. First and foremost, the material should be non-toxic and non-allergenic. It should not trigger any adverse immune responses or elicit any toxic effects. Furthermore, the coating should withstand the physiological environment it will be exposed to, such as changes in pH, temperature, and mechanical stress.

Coating application processes also play a significant role in achieving biocompatibility. The application technique must ensure uniform coverage and adherence. Proper surface preparation and application techniques are essential to avoid issues arising from poor coating adhesion or inconsistencies.

 

Why are Biocompatible Coatings Important?

Biocompatible coatings can significantly influence the body's response to medical devices and implants. A well-designed biocompatible coating can minimize inflammatory responses, prevent bacterial adhesion, and promote tissue integration. Furthermore, by providing a protective and biologically compatible barrier, these coatings enhance the safety and effectiveness of medical devices, improving patient outcomes.

There have been several successful applications of biocompatible coatings in medicine and biomedical engineering. Here are a few examples:

  • Orthopedic implants: Biocompatible coatings have been used on orthopedic implants to improve their longevity and reduce inflammation and tissue rejection.
  • Drug delivery systems: Coatings have been developed to encapsulate and protect drugs, allowing for targeted delivery and controlled release within the body.
  • Stents: Biocompatible coatings on stents help to prevent blood clot formation and promote healing in cardiovascular applications.
  • Dental implants: Coatings on dental implants enhance biocompatibility, improving the integration of the implant with the surrounding bone.

 

Coating Technologies

Various coating technologies are employed to achieve biocompatibility in different medical devices. These technologies involve using specific materials and techniques to create coatings that meet the required standards:

Chemical Composition

Different biocompatible coating materials, including polymers, such as Parylene, ceramics, and metals, are used. Each type has its unique characteristics and advantages for medical applications. Polymers, for example, are known for their flexibility and ability to mimic natural tissues. Ceramics offer excellent wear resistance and can provide a stable surface for cell growth, while metals are valued for their durability and strength.

Coating Techniques

Each coating technique has its advantages and limitations. The selection of a particular method depends on factors such as the desired coating properties, the substrate material, and the intended application. The deposition of biocompatible coatings requires specific techniques to ensure uniformity and adherence to the substrate. Several coating techniques are commonly employed in the medical industry, including:

  • Chemical vapor deposition (CVD): In this technique, a precursor gas is introduced into a chamber and reacts to form a coating on the surface of the substrate. CVD offers excellent coating conformity and is frequently used for coating stents and catheters.
  • Electrochemical deposition: Also known as electrodeposition, this technique involves using an electric current to deposit a material onto a substrate. It is typical for coating electrodes and medical implants.
  • Dip coating: This technique entails immersing the substrate into a bath of the coating material and then withdrawing it at a controlled rate. Dip coating provides a uniform and controlled coating and is often used in the fabrication of medical devices.
  • Spray coating: The coating material is atomized and applied to the substrate in a fine spray. This is a popular technique for coating dental implants and prosthetics.

 

Biocompatible Coatings Applications

Biocompatible coatings can be employed in manufacturing electronic devices, food processing equipment, and cosmetic products, among others. With their ability to provide a safe and reliable surface, biocompatible coatings offer advantages beyond the medical field.

However, within various areas of medicine, biocompatible coatings play a crucial role in enhancing the compatibility of medical devices, improving tissue engineering techniques, and revolutionizing drug delivery systems. These coatings have transformed the field of medicine by reducing rejection and adverse reactions and improving the overall efficiency of medical interventions. Three use cases are described below.

Medical Implants

One of the critical applications of biocompatible coatings is in the field of medical implants. For instance, in orthopedic implants, biocompatible coatings create an optimal environment for the implant to integrate seamlessly with the surrounding tissues and bones. Similarly, dental and cardiovascular implants benefit from biocompatible coatings, promoting long-term stability and functionality.

Drug Delivery Systems

Biocompatible coatings have revolutionized the field of drug delivery systems by improving stability, enhancing bioavailability, and enabling targeted drug delivery. The efficacy and safety of drug delivery are significantly improved by coating drug carriers such as nanoparticles, microparticles, and implants with biocompatible materials. These coatings protect the drugs from degradation, facilitate controlled release, and ensure targeted delivery to specific tissues or cells.

Biomedical Devices

Biocompatible coatings find extensive applications in various biomedical devices, including biosensors, microfluidic devices, and prosthetics. These coatings enable seamless integration and interaction with biological systems, enhancing the device's functionality and reducing the risk of adverse reactions. For example, biocompatible coatings on biosensors allow accurate and reliable detection of biomarkers, while coatings on prosthetic limbs improve their integration with the human body and enhance user comfort and mobility.

 

Factors Influencing Biocompatible Coating Selection

Selecting the most suitable material for a specific application is essential to ensure optimal biocompatibility and overall performance of the coating. There are various factors to consider when selecting materials for specific medical applications. These factors include:

  • Chemical composition: The specific chemicals used in the coating formulation can significantly influence its biocompatibility with the surrounding environment.
  • Surface interactions: Understanding how the coating interacts with the surrounding biological tissues and fluids is crucial to ensure proper biocompatibility.
  • Thickness and uniformity: The thickness and uniformity of the coating play a vital role in its ability to protect the underlying substrate and provide the desired properties.
  • Physical properties: The physical properties, such as hardness, flexibility, and adhesion strength, must be considered when selecting a coating for a specific application.

Please contact our engineers if you require a biocompatible coating material for your application or have questions about protective thin film coating properties. Meanwhile, please browse our resource section to learn about other relevant properties, such as tensile strength, yield elongation, and corrosion resistance.

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Dissipation Factor - Definition, Measurement, Variables

September 12, 2023 / by Mallory McGuinness-Hickey posted in Protection Capabilities, Coating Properties

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Dielectric materials are crucial in various industries and applications, serving as insulators, substrates, or capacitors. One important characteristic often evaluated in dielectric materials is their dissipation factor. The dissipation factor, also known as the loss tangent or tan δ, is a vital parameter that measures the dielectric losses in electrical systems and components. It quantifies the energy dissipated as heat when an alternating current (AC) signal passes through an insulating material or a capacitor.

 

Why is Dissipation Factor Important?

This property provides valuable insight into the performance of dielectric materials. It measures the efficiency with which a dielectric material dissipates energy in the form of heat when subjected to an alternating current (AC) or high-frequency signal.

By analyzing this value, engineers can detect potential issues such as insulation breakdown, heat generation, and power loss, enabling them to effectively design and optimize electrical systems. Whether in high-frequency applications, power electronics, or telecommunications, the dissipation factor assists in selecting the appropriate materials, reducing energy loss, and enhancing electrical equipment's overall efficiency.
A high dissipation factor can indicate potential problems such as inefficient energy transfer or excessive heat generation in dielectric materials. By assessing this data, engineers can determine if a material is suitable for a specific application or needs replacing.

Measurement Techniques 

The dissipation factor is calculated by dividing the loss tangent of a dielectric material by its capacitance. The loss tangent is the ratio of the dissipated power to the stored energy in the material. There are several ways to determine the dissipation factor of various materials accurately. Professionals can use these techniques to obtain precise data and evaluate the performance and reliability of materials.

Bridge Method

The bridge method is a common measurement technique. It uses a bridge circuit consisting of resistors, capacitors, and inductors. By balancing the bridge, engineers can determine the material's dissipation factor under test.

Parallel-Plate Method

The parallel-plate method is another popular technique. It involves placing the material between two parallel plates and applying an alternating voltage across them. The dissipation factor is determined by measuring the power loss in the material.

Guard-Ring Method

The guard-ring method is a technique that minimizes the effects of stray capacitance during measurement. It involves placing a guard ring around the measurement electrodes to prevent current leakage due to the stray capacitance. This method helps to improve accuracy.

Variables Affecting Dissipation Factor

Several factors can influence the dissipation factor, affecting the efficiency and performance of electrical systems. Engineers and designers can optimize electrical systems by understanding and considering these factors, ensuring efficient and reliable operation.

Temperature

Temperature plays a significant role. As the temperature increases, molecular motion and energy losses increase, leading to a higher value. It is important to consider the temperature range in which a material will be used to ensure its dissipation factor remains within acceptable limits.

Dielectric Loss

Dielectric loss refers to the energy lost as heat due to the interaction between the electric field and the dielectric material. Materials with higher dielectric losses tend to have higher dissipation factors. Selecting materials with low dielectric loss can help minimize dissipation and improve system performance.

Frequency of Operation

The frequency of operation has a direct impact. At higher frequencies, the energy losses from the materials increase significantly, leading to an increased value. It is essential to consider the operating frequency when evaluating the dissipation factor of materials for electrical systems.

Resistance in the Circuit

The resistance in the circuit also contributes to the dissipation factor. Higher resistance causes larger energy losses and a greater value. Minimizing resistance through proper circuit design and selecting low-resistance components can help reduce the overall dissipation factor.

 Material Selection

The dissipation factor provides valuable insights into the electrical behavior of components, enabling manufacturers to make informed decisions regarding their application in different industries. This value is relevant across various industries heavily relying on electrical components. Industries such as telecommunications, power generation, aerospace, and automotive require strict adherence to quality standards to ensure optimal performance and safety.

Engineers can compare materials' performance at high frequencies by evaluating this property. This evaluation allows them to select materials with lower dissipation factors, which result in reduced energy losses and improved system efficiency. Furthermore, optimizing this property can also lead to increased power handling capabilities and improved reliability. If you are designing an electronic product and need help selecting a protective coating with beneficial electrical properties, please contact our team for a consultation. Or, you can learn more about thin film coating properties.

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Volume Resistivity - Definition, Measurement, Product Design

September 12, 2023 / by Mallory McGuinness-Hickey posted in Protection Capabilities, Coating Properties

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Whether designing circuit boards or protecting electrical components, knowledge of the volume resistivity of coating materials plays a pivotal role in creating efficient and reliable electronic products. This critical measurement refers to the ability of a material to resist the flow of electric current within its volume. In other words, it measures how well a substance conducts or insulates electricity.

Defining Volume Resistivity

Volume resistivity refers to a material's resistance per unit volume when an electric field is applied. It is measured in ohm-meters (Ω·m) and depends on the material's nature and composition.


One way to understand this property is by comparing it to electrical conductivity. While volume resistivity measures the resistance to the flow of current, electrical conductivity measures how easily current flows through a material. In other words, it is the inverse of electrical conductivity. Volume resistivity is especially important in coating materials used for electrical insulation. Insulating materials like polymers or ceramics need high values to prevent electrical current leakage and ensure the circuit's integrity.

Measurement 

Due to its importance, the accurate measurement of volume resistivity is essential to understanding the electrical conductivity of materials. By determining how well a coating material can resist the flow of electric current, engineers can assess its suitability for a wide range of applications.

Several techniques are common. One such method is the four-point probe technique, which involves passing a known current through a material and measuring the voltage drop across four evenly spaced points. This method enables precise calculations of the material's resistivity. Another popular technique is the two-point method. This approach passes a current through the material using two electrodes, and the voltage drop is measured. By applying Ohm's Law, the resistivity can be easily determined.

Specialized equipment is necessary to measure this value. This equipment includes multimeters, which can accurately measure voltage and current. Custom-built setups are often employed for specific applications to ensure precise measurement results.

Influencing Factors

Various factors can influence the volume resistivity of a coating material. These factors can alter the resistance properties of a material and potentially affect its performance in electrical applications. They include the following:

  • Material composition - the composition of a material plays a crucial role in determining its volume resistivity. Different materials have different electrical properties, which can significantly influence their resistance to electric current flow.
  • Molecular structure - materials with tightly packed and well-ordered molecular structures tend to have higher resistivity as the movement of free electrons is restricted.
  • Impurities - even small amounts of impurities can disrupt the movement of electrons, leading to changes in the coating material's electrical resistance.

Relationship Between Coating Materials and Volume Resistivity

Polymer materials have different volume resistivity values, determining their ability to conduct or resist electrical current. The volume resistivity of a polymer is directly influenced by its molecular structure and composition. Some examples of polymer materials with high values include polyethylene and polypropylene. These materials are commonly used in cable insulation and high voltage applications, where electrical current needs to be contained. On the other hand, polymer materials with low values, such as conductive polymers and carbon-filled composites, are often used as electrical conductors. They are suitable for applications requiring efficient electrical current flow.

Why is This Property Important for Product Design?

Volume resistivity is a critical value that helps determine the suitability of coating material for specific applications. Engineers can select the most appropriate materials to ensure optimal performance and safety by knowing how conductive or insulating a substance is. Additionally, understanding this property helps diagnose and prevent electrical failures in electronic products. Analyzing the volume resistivity of protective coating material within an electrical system allows potential issues, such as short circuits or unexpected voltage drops, to be identified and rectified before they cause significant damage or failures. This proactive approach saves time and money while enhancing the system's reliability. Last, volume resistivity is essential in complying with industry standards and regulations. Many sectors, including electronics, automotive, and aerospace, have stringent requirements for electrical systems. By ensuring that materials used in these systems possess the appropriate volume resistivity values, businesses can meet these standards and ensure the longevity of their products.

Significance in Circuit Design

In circuit design, selecting coating materials with appropriate volume resistivity is paramount. This property plays a significant role in ensuring electronic devices' proper functioning and performance. By selecting materials with appropriate volume resistivity, circuit designers can ensure the proper operation of different components, minimize the risk of electrical failures, and enhance the overall functionality of the circuit.

Overall, this is a critical factor to consider during circuit design. It not only influences the performance and efficiency of electronic devices but also allows for the optimization of circuit design by selecting materials based on their electrical properties. If you are searching for a protective coating with volume resistivity that meets the criteria for your application, please contact us; we may be able to help. For more information about the critical electrical properties of coating materials, please visit our coating properties page.

 

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UL94 Coating Material - Testing Method, Material Selection

September 8, 2023 / by Mallory McGuinness-Hickey posted in Protection Capabilities, Coating Properties

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Fire safety compliance is an indispensable aspect across various industries. One crucial benchmark in fire safety compliance is UL94, a widely recognized standard for flammability testing of plastic materials. By evaluating the flammability characteristics of different materials, UL94 ensures that products meet the required safety standards and regulations. 

What is UL94? 

UL94 is a standard for evaluating plastic materials' flammability in various industries. It provides an objective and reliable assessment of the fire resistance properties of these materials. 

UL94 is an abbreviation for Underwriters Laboratories Standard 94, first introduced in 1972. Underwriters Laboratories (UL) is a global safety certification company that tests and certifies a wide range of products for their safety and performance. UL94 is one of the many standards developed by UL to ensure the safety of products and materials. 

The role of this standard in product and material safety assurance cannot be overstated. It helps engineers and manufacturers identify potential fire hazards by clearly demonstrating materials' flammability properties. This information mitigates risks and leads to the development of safer products. 

Flame ratings, such as V-0, V-1, V-2, HB, etc., indicate a material's ability to self-extinguish or resist flame propagation. Materials with higher flame ratings provide greater confidence in the product's safety and fire resistance. Understanding these ratings is essential in assessing the fire performance of materials and ensuring their compliance with safety standards; therefore, accurate data is critical. 

Learn about other standards, such as Ingress Protection Standards and NEMA ratings.

Testing Methodology 

The UL94 testing methodology is a standardized procedure used to determine the flammability characteristics of materials. The UL94 testing methodology subjects test specimens to controlled flame exposure, providing valuable information to manufacturers, regulators, and consumers. 

Several test methods are used in testing, including vertical burn, horizontal burn, and others. Each test method simulates specific fire scenarios and assesses different aspects of a material's flammability. Before testing, specimens are prepared according to particular requirements. This preparation includes cutting them into proper dimensions, removing any surface coatings, and ensuring consistency in sample preparation across different tests. 

UL94 testing occurs under specific standard test conditions, such as ambient temperature and flame duration. These conditions simulate real-life fire scenarios and allow for reliable material comparisons. Flame ratings are assigned based on specific criteria, such as the material's ability to self-extinguish within a particular time frame or its resistance to flame propagation. These criteria vary depending on the test method applied. 

Material Selection 

Understanding the relationship between material characteristics and fire resistance is crucial when choosing suitable plastic materials. UL94 testing helps engineers evaluate different materials' flammability, ignition, and burning characteristics to select the most appropriate options, ensuring that the chosen materials meet safety requirements and minimize potential risks.

When selecting coating materials for specific applications, there are several key considerations. These include the intended use, environmental conditions, mechanical properties, and chemical and fire resistance. A comprehensive understanding of UL94 test results enables engineers and designers to make well-informed decisions regarding material selection. If you are looking for a UL94-rated protective coating material or have questions for our engineering team, please contact us today. Or you can learn more about thin film protective coating properties, such as dielectric constant, Young's Modulus, biocompatibility, and glass transition temperature.

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Elongation Yield: Overview, Unit of Measure, Data and Testing

August 29, 2023 / by Mallory McGuinness-Hickey posted in Protection Capabilities, Coating Properties

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Elongation yield refers to the maximum amount of deformation a material can undergo before it experiences a permanent change in shape or size. This property is fundamental in determining various coating materials' mechanical strength and behavior, making it an essential factor in design engineering and product design.  

Understanding how this property affects material performance is crucial in determining the suitability of coating material for a particular application. It directly affects the material's ability to deform without breaking and sustain loads without failure. This high-level overview will discuss elongation yield and its implications for product design. 

Elongation Yield: Material and Unit of Measure 

Elongation yield can be measured in various coating materials, including metals, polymers, and composites. Coating materials such as metals with higher values typically exhibit greater ductility, the measure of a material's ability to deform before fracture. 

On the other hand, coating materials with a lower elongation yield tend to be less ductile and more prone to brittle behavior. They have limited ability to deform before reaching their breaking point. Such materials are usually more suitable for applications that require high strength and rigidity but not necessarily significant deformation. 

Polymers, including plastics and rubber, display higher values than metals, enabling them to withstand extensive stretching or bending before breaking. 

Composites, which consist of two or more different material components, can possess varying characteristics depending on their composition. The individual materials within a composite can have different abilities to undergo elongation yield, making the overall behavior complex. 

Unit of Measure 

Two standard units of measure are used to quantify elongation yield: percentage and millimeters. 

The percentage unit of measure represents the elongation yield as a percentage of the original length of the material. For example, if a metal specimen stretches 10% before breaking, it has elongated by 10% of its original length. 

On the other hand, millimeters are used to measure the actual physical elongation of a material. This unit of measure provides a more tangible representation of the deformation a material undergoes before reaching its breaking point. 

Both units of measure have their advantages and are suitable for different applications. The choice between percentage and millimeters depends on the material type, testing specifications, and industry standards. 

 

BL0141-Yield Elogation-Inline 1

Data and Testing Method for Measuring 

When determining a material's elongation yield, reliable data and thorough testing methods are essential to ensure accurate measurements and a deeper understanding of how a material will perform under various conditions. The data obtained during material testing provides valuable insights into the behavior of a material and its elongation yield. It includes measurements such as strain and stress, which calculate values. 

  • Strain refers to the deformation experienced by a material when subjected to external forces. It is measured as the change in length divided by the original length. 
  • Stress is the force applied per unit area and is assessed by dividing the applied force by the original cross-sectional area. 

By analyzing the relationship between stress and strain, engineers can identify the point at which the material starts deforming permanently, known as the elongation yield point.  

Overview of the Different Testing Methods Used

Various testing methods are employed to measure this property, each offering advantages and limitations. Tensile testing, for example, is commonly used to evaluate a material's mechanical properties, including elongation yield. 

In tensile testing, a material sample is subjected to controlled tension until it reaches its elongation yield point. The resulting data helps determine the material's ability to withstand loads and deformations. 

On the other hand, impact testing measures the energy absorbed by a material when it fractures under sudden stresses. This method provides valuable insights into the material's toughness and resistance to sudden impacts. 

Other testing techniques, such as bend and hardness tests, can also provide insights. The bend test involves subjecting a material to bending forces to determine its flexibility and resistance to deformation. On the other hand, the hardness test measures the material's resistance to indentation, indirectly indicating its elastic deformation capabilities. 

Specific standards established by regulatory bodies and industry organizations govern the testing procedures. These standards ensure consistency and comparability of test results across different laboratories and manufacturers. 

Importance in Material Selection and Design 

Engineers and designers can make informed decisions regarding coating material by considering the elongation yield. They can determine the material's capacity to stretch and deform before reaching its breaking point, safeguarding the reliability of the end product.  

Moreover, understanding the elongation yield can also help optimize designs, reduce material waste, and enhance overall efficiency. Engineers can create designs that balance strength, flexibility, and cost-effectiveness by accurately predicting the coating material's behavior based on elongation yield values.  

Electronic product reliability hinges on protective coating durability. If a coating breaks in any way, it could open the door to corrosives, chemicals, and other contaminants that could cause electronics to stop working. Therefore, understanding the elongation yield value is vital in ensuring electronic products' safety, durability, and performance in real-world applications. If you need help identifying the best coating material for your application, please contact our Applications engineers for a DFM consult. Alternatively, you can learn more about our coating protection capabilities, including Young's modulus, elongation at break, and tensile strength at yield.  

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Difference Between Water Resistant, Repellent, & Proof

August 10, 2023 / by Mallory McGuinness-Hickey posted in Protection Capabilities

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graphic explaining the difference between waterproof, water-resistance, and water-repellent

We all see references to waterproof, water-resistant, and water-repellant devices being thrown around on electronic products. The big question is: What’s the difference? There are a lot of articles written on this topic, but we figured we would throw in our two cents as well and take a closer look at the differences between all three terms, with a specific focus on the world of devices.

 

a waterproof phone underwater

 

First of all, let’s start with some quick dictionary definitions of waterproof, water-resistant, and water-repellent, as given by the Oxford English Dictionary:

  • Water-resistant: able to resist the penetration of water to some degree but not entirely
  • Water-repellent: not easily penetrated by water, especially as a result of being treated for such a purpose with a surface coating
  • Waterproof: impervious to water

 

What Does Water-Resistant Mean?

Water resistance is the lowest level of water protection of the three. If a device is labeled as water-resistant, it means that the device’s construction makes it more difficult for water to get inside of it or possibly that it is coated with a very light substance that helps improve the device’s chances of surviving an encounter with water. Water-resistant qualities are great for products such as watches because they help those products withstand light rain or washing your hands.

What Does Water-Repellent Mean?

Water-repellent coatings are the next step up from water-resistant coatings. Devices labeled as water-repellent have properties that repel water from them, which makes them hydrophobic. Water-repellent devices have a better chance of surviving a watery encounter. Most have thin-film nanotechnology, which can coat the inside and outside of an electronic device.  Many companies claim water-repellency, but the term is heavily debated because a durable water-repellent is rare and because of all the questions and unpredictable elements associated with it.

What Does Waterproof Mean?

Defining “waterproof” is simple, but the concept is more complicated. There is no established industry standard to classify a device as waterproof. The closest thing currently available, as far as a rating scale is concerned, is the Ingress Protection Rating scale (or IP Code). The IP Code assigns items a rating from 0-8 in terms of how effective the device is at keeping water from entering into it, a process called the ingress of water. One major flaw in this rating system: What about companies like us here at HZO who are not concerned about keeping water out of a device to save it from water damage? Our coatings allow water inside devices, but the waterproof material we coat them with protects them from any possible water damage. HZO’s services have a different intention than the effect the IP scale can measure. Still, our coatings help you protect your electronic devices from water damage.

Companies take a measured risk when labeling a product as waterproof. Most consumers assume that waterproofing is a permanent condition. Still, devices exposed to “waterproofing” can face water damage in certain situations.

Using the term waterproof can also be considered a risky move for many companies. This is because "waterproof" usually communicates that this is a permanent condition and that whatever has been ‘waterproofed’ will never fail due to contact with water–no matter the situation.

With all the controversy surrounding the correct use and results associated with these terms, it’s no wonder many people use them incorrectly. Unsurprisingly, the products labeled as water-resistant, water-repellent, or waterproof are often misrepresented due to incorrect labeling. The words almost need new definitions with how far technology has come since these terms were first used. We also need a standard to measure a device’s waterproof qualities and represent the possibilities and kinds of technology like HZO that are commercialized and available to device makers now. This outdated scale can’t measure the power of our coatings.

 

What About Splashproof?

A splashproof product has a limited ability to resist water damage and is not immersible. For example, if you take your splashproof headphones with you on a run, they’ll be safe from sweat or droplets from your water bottle, but they won’t survive falling into a puddle.

Using the IP scale can demonstrate the differences between splashproof vs. waterproof products. Most waterproof electronics have an IP67 rating. A product qualifies as splashproof if it has an IP44 rating.

The scale from splashproof to waterproof includes:

  • IP44. An IP44 product withstands splashes from any direction, making it splashproof. These products are safe from solid materials larger than 1 millimeter.
  • IP55. These products resist low-pressure jets from any direction. IP55 products also have some protection against dust.
  • IP66. An IP66 product can withstand strong jets from any direction and completely protect against dust.
  • IP67. These products are suited for complete immersion at a depth of 1 meter for 30 minutes. This distinction qualifies them as waterproof. They also have total protection against dust.

 

An HZO Protected World

Because of the advanced level of protection available for electronics that protect them from water, sweat, other liquids and corrosion, the need for new standards is necessary to raise the bar in the minds of consumers. That’s why HZO is seeking to create an HZO Protected World and asking for people everywhere to help us tell the device makers of the world that we want electronics that have better, more reliable protection. Protection from the Inside Out.

 
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Top Electronics Manufacturing Industry Publications

June 15, 2023 / by Mallory McGuinness-Hickey posted in Resources

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If you work in the electronics manufacturing industry, you are likely plagued with information overload, whether you are an engineer, purchasing professional, or business-oriented decision-maker.

For example, one study shed light on the sheer volume of information electronics design engineers must search for and select. In the research, the engineers reported that one of the most significant burdens associated with their job was identifying and selecting dozens of technical documents, best practices, evaluations, product searches, design tools, and information on regulatory requirements.

With all the information-seeking that people who work in electronics manufacturing must do, spending extra time wading through general news, analysis, press releases, and events to find topical, relevant content only adds to the frustration.

As a technology company involved in the industry, we know this problem too well. That’s why we have compiled a list of what we consider to be some of the best electronics manufacturing industry publications (in no particular order) and how to use these resources best.

 

1. Circuitnet (Link)

Circuitnet digs through the seemingly unending influx of articles, discussions, news, and features to deliver news and information relevant to the world of electronics manufacturing. The site features an “Ask the Experts” panel, where industry leaders weigh in on questions you may have, an industry calendar lists events essential to electronics manufacturing, and a technical papers section can be used to access technical content for free (although you will have to exchange basic information and email). You can use the search bar if you cannot find what you are looking for immediately.

How to use this resource:

While the Circuitnet site is robust, it also sends a news digest to subscribers’ inboxes every business day. This newsletter is a quick way to stay updated on information and trends pertinent to you, corporate or product announcements that serve as helpful tips, and industry events. Circuitnet also publishes more than forty feature articles a month on PCBs, the assembly process, and packaging and design, so you can ensure your knowledge is current.

CircuitNet’s Ask the Expert Panel

 

 

2. Circuits Assembly Magazine (Link)

Circuits Assembly Magazine provides fabricators, suppliers, and industry designers with best practices and insights to inform them about electronics industry trends. The website features podcasts, which you can easily access from the homepage, covering various topics from reliability to thermal management. Along with news and features, another section lists relevant press releases to keep you updated with industry developments.

How to Use this Resource:

Every month, Circuits Assembly Magazine offers a digital magazine that you can easily read on your computer, tablet, or phone. The magazine is also available in print, but we prefer the digital type, as it is easy to scroll through and quickly find articles of interest.

A Sample of This Month’s Circuits Assembly Magazine Edition

 

 

3. SMT Today (Link)

SMT Today integrates traditional communication (including a bi-monthly print magazine) and the latest technology to keep readers in the electronics industry current. On this site, you will find a newsletter, electronics, industry news, an up-to-date industry event calendar, and separate sections dedicated to equipment, materials, and software/integration news.

How to use this resource:

While you can sign up for the newsletter or read the magazine, the streamlined, organized interface of the website allows you to find what you are looking for quickly. We love to go to the homepage and use the menu bar to filter out the information we need immediately.

 

4.  SMTnet and the Express Newsletter (Link)

SMTnet is a web portal dedicated to the electronics industry covering PCB assembly, Surface Mount Technology, and EMS process, from concept to delivery. This site is relevant to any industries involved in electronics, including information for engineering personnel, purchasing agents, and business segments. The site includes an electronics forum, technical library, industry directory, equipment auctions, videos, training courses, and other resources.

How to use this resource:

Although the SMTnet site alone is a great source that includes unique information, we particularly love the SMTnet Express Newsletter. This condensed yet information-packed weekly newsletter includes topical technical articles, forum highlights, equipment purchase and sale updates, upcoming events, and available training courses, with the latest job openings to boot.

Feb 3 edition of the SMTNet Express Newsletter

 

 

5. Global SMT & Packaging (Link)

Global SMT & Packaging provides a variety of articles, news, and expert commentary on advanced packaging-related assembly and surface mount of PCBAs. The variety of content formats available is what makes this website stand out. You can find podcasts, “Tech Talk Thursday programs,” expert panel debates, newsletters, webinars, and programs.

How to use this resource:

Covid has suspended our ability to participate in as many conferences and trade shows as we used to, so we use this site to stay connected by watching webinars, listening to the panel discussions, and tuning into the Tech Talk Thursday programs.

Featured Articles

 

6. Economist (Link)

If you are searching for current affairs on electronics from a trustworthy news source, we recommend The Economist. The Economist is known for strict copyediting, rigorous fact-checking, and minimal reporting bias. It makes an excellent go-to if you want just the news with minimal sensationalism or subjectivity.

How to use this resource:

To use The Economist to find electronic news, use the search function, using “electronics” as a keyword. You can sort by date, ensuring you can find the most topical news events quickly.

 

The Economist search function, along with the latest news articles about electronics.

 

7. EMSNOW (Link)

EMSNOW provides the Electronic Manufacturing Sector, associated suppliers, and customer basis with real-time information and analysis covering the industry's global aspects. Along with videos, features, podcasts, and “Coming Events,” you can find columns here as well, and much of the information has been published yesterday or today.

How to Use this Resource:

EMSNOW is a go-to for the most up-to-date information. While we love weekly and monthly publications, we recognize that having new information is important and sometimes critical before making certain business decisions. We recommend checking in with EMSNOW once or twice weekly to stay updated on current news and analysis.

A Sample Analysis Column from EMSNOW

 

8. Electronics Sourcing (Link)

Electronics Sourcing is a magazine for purchasing professionals within the electronics distribution & manufacturing sector who buy, distribute, and sell electronic components and associated products. You can head to the website to sign up for the magazine and find relevant market news and magazines targeted to the UK & Ireland, North America, or Europe, which is a nice touch.

How to use this resource:

Although we love the content, the purchasing tools tab on the website menu bar is especially valuable. Here you can find Buyers’ guides for the UK & Ireland, North America and Europe, search or components, and component sourcing information.

Screengrab of the Latest News Section of the Homepage

 

9. ASSEMBLY Magazine (Link)

ASSEMBLY Magazine provides information on processes, strategies, and technologies for assembling parts in appliances, medical, automotive, and aerospace industries. You can find the Assembly eMagazine, podcasts, how-to guides, ebooks, webinars, and more here. The site offers a newsletter you can sign up for to quickly avail yourself of their latest resources regularly from your inbox.

How to use this resource:

Our favorite feature on this site is the ASSEMBLY InfoCenters section that you can access from the menu bar. One InfoCenter is dedicated to sensing solutions, for example, and it includes application stories, sensing insights, upcoming events, and a summary of relevant products.

Example of an ASSEMBLY Magazine Column

 

10. U.S. Tech (Link)

U.S. Tech has been distributing breaking news about electronics production since 1985. The website features a Daily News Archive, videos, white papers, a “Tech Watch” column, and an industry calendar, among other helpful information.

How to use this resource:

We recommend you sign up for the printed newsletter, published nine times yearly. Each addition offers a different view of the current state of electronics manufacturing from various technical perspectives. 

Tech Watch Article

 

Wrapping Up

We hope this list was helpful and can be used to save some of your time. Please don’t forget us either! We provide Parylene conformal coatings and nanocoatings and discuss our technology, electronic reliability, design, industry news, and the business implications of sound engineering design on our blog and social media channels.

Follow us on LinkedIn.

 
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ADAS Design and Validation for the Real World - Automotive Coatings

June 15, 2023 / by Mallory McGuinness-Hickey posted in Parylene, Coating Properties, Thin Film Applications

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Advanced driver assistance systems (ADAS) continue to expand in features and functionalities. Standard offerings may include adaptive cruise control, park assist, blind-spot detection, lane departure, RADAR, emergency braking, tire pressure monitoring, and LiDAR systems.
 

When consumers purchase a vehicle with ADAS safety features, they believe they have a layer of protection to be entirely relied on. In reality, though, without a methodical, effective ADAS component design that accounts for real-life situations, these features are no more than crutches.

In addition to the ethical argument that safety should be an underlying principle of ADAS design, liability concerns create a business case for ADAS components that dependably function in the typical automotive service environment.

As ADAS designers evaluate the risk of harm, they may ask about the probability of exposure to an element or situation that could cause failure. They may ascertain how severe the resulting damage may be and determine how controllable the issue is if it should occur.

The risk of harm is high in instances such as premature ADAS component failure due to harsh environments. ADAS PCBAs and components will inevitably encounter corrosive elements, humidity, thermal shock, water ingress, and other environmental factors that compromise electronics. If this ADAS component should fail as a result, consumers relying on a safety feature could incur severe damage and liability, and in terms of controllability, there is not much that can be done upon critical component failure.

ADAS component reliability through harsh environments is a high-risk issue. Therefore, design engineers must prioritize safeguarding ADAS components from failing in these circumstances and verifying their safety in real-life situations. Testing and validation can become problematic when legacy methods such as gaskets and seals bolster ADAS reliability.

 

ADAS features in harsh environments

 

Possible Issues with ADAS Testing Protocols and Traditional Reliability Methods

Issues with ADAS reliability testing protocols may include:

● Testing must confirm that a system will handle situations that can be predicted and that ADAS will reliably work under unknown circumstances.
● Proper validation and verification can entail testing many conditions, particularly as vehicle design shifts towards fully autonomous vehicles.
● Testing for scenarios on a test track may be impractical when methods such as seals and gaskets are used for ADAS reliability.

For example, to test that a seal will continue to prevent ingress while exposed to vibration, you might have to wait for weather conditions to occur naturally, including snow, rain, or humidity. Although you can use equipment to mimic these weather conditions, this will add to testing complexity.

It's Possible to Simplify ADAS Reliability

As noted, seals and gaskets can become dislodged in many situations, which would have to be recreated and accounted for to validate and verify ADAS component reliability if they are the primary protection method. This unpredictability raises complications during the design and validation process.

Furthermore, as more features are built into vehicles, more components will need to fit in. The bulk of seals, potting, and traditional conformal coatings can lead to more design challenges. These conventional methods can also complicate lightweighting efforts as they add unnecessary weight.

HZO’s proven, trusted Parylene coatings solve these testing and design challenges. These conformal coatings come in several types, including Parylene N, Parylene F (VT-4), and Parylene C, demonstrating excellent performance in mission-critical applications for decades, in part due to uniform coverage, barrier properties, and less stress on mechanical structures.

 

HZO Coatings for Automotive Corrosion Protection

We’ve proven that our coatings can deliver as much – or more – flexibility, fungus resistance, flammability, dielectric withstanding voltage, thermal shock, moisture, and insulation resistance at a fraction of the mass of conventional coatings, passing the IPC CC-830C test at 50% of the film thinness. Unlike seals and gaskets, Parylene does not stop providing protection when exposed to unpredictable situations, such as drops and falls. The coating is well studied and, when appropriately applied by engineers who understand the parameters of an application, will withstand the lifecycle of the product it is enabling.

 

Class Type Specimen – Average Coating Thickness [μm]
    1 2 3 4
XY Parylene N 25 25 23 23
XY Parylene C 31 30 30 32
XY Parylene F 46 36 43 29
AR/UR Acrylic 73 73 69 72
SR Silicone 102 99 114 154
AR/UR Acrylated Polyurethane 91 91 107 107

 

Below, you can see how our coatings performed in automotive validation tests.

Contents Requirements Test Results
Operations Test Operate for 24 hours at 23 Degrees C Operate for 24 hours at 23 Degrees C
Coating Property No Pinhole and Uncoated Area No pin hole and uncoated area
Coating thickness 225±3 [μm]
Electrical Test Dielectric withstanding voltage: Over 1.5 [kV]
Insulation resistance: Over 10 [GΩ]
IPC-B-25A standard test board pattern Dv
Over 1.5 [Kv]
Over 10 [GΩ]
Corrosion Test Salt spray (35 °C, NACI, 96 hours):
No corrosion on chip leads
No corrosion on chip leads

 

 

Enhanced Component Reliability and Increased Resistance to Fluids and Oils

 

The automotive operating environment includes exposure to chemicals such as oil, antifreeze, standing water, and cleaning fluids. HZO Parylene coatings offer dependable protection for various leak, environmental, splash, and submersion test requirements.

 

Protection Characteristics Unprotected PCB Mechanical Seal Silicone/Acrylic Coatings Parylene Coating
Protection Barrier None Good, but can be compromised with drops & temperature. Good, but can be thick & porous depending on the application. Excellent. Can peel if not properly applied.
Hydrophobic No No Yes Partial
Thickness N.A. Millimeters μm – Millimeters 2μm – 50μm
Protection Against Water Poor Good – Ingress Poor – Penetration Good Excellent
Salt/Chemical Protection Poor Poor Varies Excellent
Durability Low Varies Varies High
Submersion Test Time to Failure Seconds (IP Rating N.A.) Varies Varies Days to Weeks (IPX7 – IPX8)

 

 

When used as a redundant solution along with legacy methods, our coatings can provide more robust, reliable protection and the ability to reduce sealing, thereby minimizing spacing and weight issues. As the visual below indicates, a mechanical seal can easily be breached. With HZO’s Parylene protection, moisture ingress is not an issue.

 

 

Contact HZO for Automotive Component Coatings

 

If you are interested in Parylene and would like to speak to our industry-leading applications engineering team, please reach out with a message or fill out a quote form to understand your application needs and provide a tailored solution.

 
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Traditional Waterproofing vs. Conformal Coating Waterproofing

June 6, 2023 / by Mallory McGuinness-Hickey posted in Protection Capabilities

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Traditional Waterproofing vs. Conformal Coating Waterproofing

These days, we take our electronic devices everywhere and expect them to be waterproof. People want to take photos at the beach and in the swimming pool, some tweets and texts must be delivered while in the shower, and bath time isn’t the same without a movie on your shiny new iPad.

We get it.

The problem is that water is in more places than you realize. Liquid can creep into devices in more ways than we can see, and what you may consider a “safe place” to rest your device may not be safe. Lately, companies all over the world are trying to stop this problem. Everywhere you turn, a new phone, camera, or tablet is announced with the added benefit of “waterproof” protection.

 

rubber seals used as waterproofing methods

 

Traditional Device Waterproofing

For a phone, headphones, tablet, or wearable to be deemed waterproof, it has to be completely sealed against water. Most companies add this protection by either “ruggedizing” the product, which generally makes it pretty big and bulky, or by adding seals to the inside that act as a barrier against liquid ingress. Physical barriers sound like a great idea until you consider that these seals are easily damaged or dislodged.

When the product is dropped, when the temperature around the product becomes too hot or cold, or when the seal is not placed properly, the seal can allow water and moisture inside the product. Even a tiny amount of liquid can cause long-term problems with corrosion and short-circuiting that won’t be noticed until it’s too late. Say goodbye to all the pictures you took last Christmas and shots of your favorite cat, Sprinkles. They are gone for good.

 

a PCB being held

 

Waterproofing with Conformal Coatings

Now that you know these “waterproof” products are only as waterproof as the rubber seals inside, this is where we come in. If you haven’t figured it out by now, we here at HZO offer the world an alternative to internal rubber seals and bulky, ugly cases. We don’t protect against water leaking into your device. We protect against water in your device. HZO coatings create a barrier between your product and any liquid that could potentially cause harm to a completely waterproof electronic.

 

 

To learn more, contact us today.

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Parylene Conformal Coatings - Parylene Conformality Explained

June 6, 2023 / by Mallory McGuinness-Hickey posted in Parylene, Coating Properties

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Parylene (p-polyxylylene) conformal coatings are unique due to their capacity to be polymerized and deposited by the chemical vapor deposition (CVD) method onto surfaces near room temperature. As a result of this process, pinhole-free, high-purity, extremely thin coatings are formed out of dimer materials.

Regarding conforming to complex or unusual surfaces, Parylene is one of the best polymer coatings for moisture resistance. This attribute and the fact that Parylene is a stable chemical compound that creates an excellent barrier make it the optimal choice where resilient electronic products are a mandate. But why is Parylene coating conformal?

Download HZO’s Parylene datasheet to learn more about Parylene’s properties

 

Why is Parylene Coating Conformal?

Liquid coatings with application methods such as dipping, brushing, or spraying may cause the coatings to exhibit meniscus forces or pull away from edges, which does not occur with Paylene deposition. With CVD, the coating penetrates around and beneath closely spaced components with consistent, uniform buildup, allowing for substantial physical and electrical protection with a substantially thinner layer than conventional coatings.

 

Parylene Deposition Process

Thus, the Parylene coating process explains why Parylene is so conformal. You can read an in-depth description of the CVD process versus PECVD in our blog on the subject; below are some general benefits of CVD:

Download a visual explanation of the process

 

  • CVD produces coatings with complete coverage even around and beneath closely spaced chips and wires.
  • CVD deposits Parylene molecule by molecule onto substrates with precision and control.
  • The Parylene deposition process requires no catalyst, hardener, or heat curing.
  • Polymerization does not release harmful by-products, as with other conformal coatings.

Chemical vapor deposition process

 

When Parylene polymers are deposited from the vapor phase with the CVD process, all sides of a component are impinged by the gaseous monomer and uniformly coated. This feature of the process is responsible for why Parylene coating is conformal.

 

Importance of Conformality and Uniformity

Truly conformal coverage occurs when a film precisely follows the coated component’s geometry. Conformality allows for the optimization of surface properties regardless of the shape of the part and ensures that microdevice properties such as conductance do not vary due to significant variations in thickness. Uniform thickness is critical to prevent proper reinforcement against degradation and wear.

 

Parylene Conformality Compared to Liquid Coatings

 

Parylene conformality

 

Along with performance concerns, achieving uniformity improves production factors such as yield rates and repeatability. With the chemical vapor deposition process, engineers have confidence that there will not be thickness fluctuations from product to product and that specs are being met. By ensuring optimum coating deposition performance is met, you can lower your total cost of ownership by keeping your repeatability and yield on target.

 

Parylene Conformal Coating Service with HZO

However, although a process may achieve repeatable, uniform thickness distributions, this does not mean it is viable for your company – uptime and upfront costs must also be considered. Parylene has traditionally only been used for mission-critical applications such as medical products. HZO, a turnkey CVD process provider, has made Parylene and its application feasible for most industries for years. Our engineers have crafted capital coating equipment that addresses upfront cost concerns and makes Parylene scalable. If you are interested in the powerful barrier properties of Parylene films and the benefits of its vacuum deposition process, reach out today to speak to one of our engineers.

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What is Parylene Coating Used For? Is it Right For My Project?

June 6, 2023 / by Mallory McGuinness-Hickey posted in Parylene, Thin Film Applications, Value of Coatings

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For decades, Parylene coatings, including Parylene C, Parylene F (VT-4), and Parylene N, have been trusted to enhance the reliability and performance of printed circuit boards and electronic components within critical industries and applications. Parylene films boast superiority in barrier properties and uniform coverage with a capacity to perform at comparably minimal coating thicknesses compared to conventional conformal coatings (liquid coatings).

Polymerized and deposited onto components at around room temperature by a chemical vapor deposition (CVD) process, Parylene coatings are free of defects and pinholes, have high purity, and are ideal for applications where reliability and performance are priorities.

 

What is Parylene Coating Used for? Useful Parylene Properties

Parylene is widely used due to various beneficial properties, including exceptional resistance to moisture, chemicals, and corrosion. Parylene is biocompatible, has beneficial optical properties, and offers additional value with impressive dielectric strength. Maintaining performance through high-temperature cycles and good thermal performance are also valuable attributes.

To see the specific properties of Parylene, you can view and download the HZO Parylene datasheet below. HZO Guardian Plus™ is the Parylene C offering, and HZO Guardian Zero™ is the Parylene N coating solution suitable for halogen-free applications.

 

Common Parylene Applications

 

 

Parylene is used in a wide range of industries, including:

Medical devices – As an FDA-approved material, Parylene has long been trusted with mission-critical medical applications, such as implanted devices. However, more medical wearable manufacturers are implementing Parylene to yield high reliability for devices such as hearing aids, CGMs, and trackers.
Industrial – Parylene’s properties are ideal for protecting applications in harsh industrial environments. Parylene can enhance the reliability of HVAC and oil and gas sensors, smart meters, and more.
Consumer Electronics – Parylene has become more widely used in electronics such as hearables, wearables, and smart home devices.
Automotive – Pinhole-free Parylene coatings enhance the reliability of automotive components, including EV batteries, ECUs, and ADAS components.

 

Bottom Line – Is Parylene Right for My Application?

Should you use Parylene for your next project? It is first necessary to ask yourself how much reliability and performance matter to answer this question.

When product designers have to be sure their electronics will work when needed, Parylene is worth considering. Additionally, Parylene coatings may be your best bet when reliability and lightweight protection are mandated. Some markets, such as aerospace and automotive that must minimize weight in every instance to support fuel efficiency may benefit from ultra-thin Parylene coating.

Some products do not require such strong barrier properties and corrosion resistance. It’s not necessary to ruggedize all devices. Doing so for products intended to be disposable would raise costs for the manufacturer and the consumer, delay the release of new products, and wouldn’t serve a purpose. The added cost of enhancing the reliability of disposable electronics that rarely contact harsh environments wouldn’t be cost or time-effective.

So, while it is not always necessary or even advisable to attain critical levels of reliable protection – when it is, Parylene coatings are the best defense.

Watch the webinar about Parylene’s proven corrosion resistance.

 

 

Parylene Services with HZO

parylene coating equipment

 

HZO is a Parylene service provider focusing on driving down costs associated with Parylene coating and increasing coating efficiency. While Parylene was once associated with only mission-critical applications such as military or aerospace, we have democratized the Parylene process for our customers of all industries. Our custom-built Parylene coating equipment reduces time to market and improves throughput and turnaround time so that virtually any industry can benefit from superior protection.

We also have industry-leading Parylene masking automation and expertise with Parylene removal

Contact us if you are considering Parylene for your project and want partners with industry knowledge and domain expertise.

 
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Dielectric Constant of Insulator Materials: Formula, Table of Values

October 12, 2022 / by Mallory McGuinness-Hickey posted in Protection Capabilities

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Depending on their formulated ingredients and molecular structures, thin film coatings may be electrically conductive, insulative, or semiconductive. Insulative coatings serve several purposes, including providing dielectric strength to protect components exposed to high voltages and arc resistance. Dielectric constant (relative permittivity), the ability of plastics to store electrical energy, is another important electric function.
 
Read more about the dielectric strength formula.
 

Why is Dielectric Constant Important?

Knowing the dielectric constant is vital because lower and higher values are conducive to different applications.

For example, coatings with low values are preferred for high-frequency, high-speed circuits because they contribute little capacitance (ability to store electric charge). In these applications, high capacitance causes changes in component values and delays in switching times. The capacitance of a parallel plate capacitor is directly proportional to the dielectric constant of an insulator separating conductors and the area between the conductors. Therefore, capacitance can be reduced by using an insulator with a low value.

On the other hand, coatings with high dielectric constants and low dissipation factors make useful capacitors.

 

What is a Good Dielectric Constant for Insulating Coatings?

Dielectric constants for insulating coatings range from 2 to 8. Optimal electrical insulating coatings have low values and retain them over wide frequency, humidity, and temperature ranges.

The values arise from their electronic polarization abilities, and materials with low values include perfect vacuum, gases such as helium, nitrogen, and dry air.

The table below shows the dielectric constant of selected polymer conformal coatings.

Conformal Coating Type Dielectric Constant (1MHz) Desired
Parylene N 2.65 Low
Parylene C 2.95 Low
Acrylic 3.0- 4.0 Low
Epoxy 3.3 – 4.0  Low
Silicone 2.6 – 2.7 Low
Urethane 4.2 – 5.2 Low

 

How is it Calculated?

This constant ε is referred to as the dielectric constant or permittivity and is represented by the equation:

Dielectric Constant Formula

where Cm is the dielectric material’s capacitance and Cv is a vacuum’s capacitance.

ASTM D150 is a standard test method for measuring dielectric constants in which a sample is placed between two metallic plates of a measuring device. Capacitance is measured with the specimen in place and without. The ratio of these two measurements is the dielectric constant.

What Affects Values?

Values depend upon many factors, such as moisture content, frequency, and temperature. For example, the value will increase with increasing temperature at a constant frequency. Additionally, it may decrease or increase depending on variations in its composition. For instance, adding ceramic fillers with high dielectric constants will increase values.

Ultimately, it is important to gather accurate, reproducible data from testing that simulates the environment in which a component will operate to choose the best coating. Learn more about coating thin film coating properties such as volume resistivity and dissipation factor here.

 
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What is the Dielectric Strength Formula? Testing, Table of Values

September 16, 2022 / by Mallory McGuinness-Hickey posted in Protection Capabilities

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Although thin film coatings serve many purposes, providing dielectric isolation and electrical insulation is one of the essential functions. Dielectric strength is an important electrical parameter that helps design engineers understand the effectiveness of a coating’s insulation resistance. It is helpful to be familiar with the exact electrical values for this property and to know how the values may be affected by environments, such as humidity and temperature, and purity, structure, and composition of the coating material.

Read more about electrical properties such as dissipation factor and dielectric constant of insulator materials.

 

What is Dielectric Strength, and Why is it Important?

Dielectric strength is a coating’s ability to endure an applied voltage without breakdown. This parameter is the highest voltage (typically stated in volts per mil thickness) at which no dielectric breakdown occurs. It quantifies how strong a conformal coating’s insulation is, with a higher number signifying the insulating material’s high resistance to dielectric breakdown.

Maintaining dielectric resistance is critical for impedance and signal integrity concerns, as the insulating material must keep the circuit working correctly. Enhancing dielectric strength protects the circuit board’s long-term function. The safety and effectiveness of a device with a circuit board rely on an entirely closed system, so insulation with high dielectric resistance is critical.

Additionally, PCB designs can be more compact when they feature a coating with increased dielectric strength. Integrating more capability into smaller form factors in the demanding electronics industry is crucial to staying ahead of the curve.

At both high and low voltages, dielectric considerations are particularly important for the reliability of electronic circuits.

Knowing the dielectric strength of a coating is critical for designing reliable electronics intended to operate at high voltages, as higher values represent a better insulator quality. If a coating is exposed to a voltage that causes breakdown, it will be rendered useless. Therefore, the data should be accurate – measured carefully to obtain reproducible results under specified conditions in a test.

Understand thin film properties in greater detail

 

Dielectric Strength Vs. Dielectric Breakdown Voltage Vs. Dielectric Constant – What is the Difference?

Dielectric breakdown voltage is the voltage threshold at which actual failure occurs. This value is also expressed in volts per mil thickness; these two terms are used interchangeably.

Dielectric strength and dielectric constant are both electrical properties. However, the former is the maximum voltage that can be applied to a material before it loses its insulating properties, and the dielectric constant is the capacity of a material to store electrical energy. These values are also expressed differently. Dielectric constant is a ratio with no units of measurement.

 

How is It Measured?

Several standard dielectric strength tests exist, including ASTM D149 and IPC-TM-650, Method 2.5.7. There are three basic procedures: the short-time method, the step-by-step method, and the slow rate-of-rise method. All these methods entail the same setup – a test specimen placed between two electrodes in oil or air.

In the short-time method, the most common test, voltage is applied across the two electrodes and raised to dielectric breakdown at a uniform rate. Breakdown is an electrical burn-through puncturing the specimen or decomposition in the sample.

 

circuit board coated with high dielectric strength parylene

Dielectric Strength Formula

With this test data, it is possible to calculate dielectric strength. The formula is to divide the breakdown voltage by the thickness of the sample. The value is reported in volts per mil thickness.

 

What Material Has High Dielectric Strength?

Organic coatings generally have much higher dielectric strength than inorganic or ceramic coatings. Materials that contain impurities, voids, and moisture will have lower breakdown voltages.

The table below shows the material dielectric strength of polymer conformal coatings.

 

Conformal Coating Type Dielectric Strength Desired
Parylene N 7000 High
Parylene C 5600 High
Acrylic 1200 High
Epoxy 900-1000 High
Silicone 1100-2000 High
Urethane 1400-3000 High

Source: Handbook of Plastics, Elastomers, and Composites, 4th Edition, McGraw Hill, Inc. New York, 2002. Chapter 6.

 

Why Do Insulating Coatings Break Down, and What Affects Dielectric Strength?

Even the most effective insulation materials contain a few free electrons and ions due to molecular imperfections or thermal agitation. The physical breakdown of the coatings is likely due to an electron “avalanche” effect (a large increase in electrons) within the coating. Several factors can affect this value. First, the thickness of the coating has an effect. Thinner coatings have higher values. A coating’s purity and physical integrity (lack of air void and pinholes) contribute to its effectiveness as an insulator. Dielectric strength decreases as impurities or imperfections increase. In terms of operating environments, exposure to moisture and elevated temperatures cause pronounced declines in values. In some instances, though, the final value is sufficiently high for most applications. To learn more about the electrical parameters of thin film coatings, read our protection capabilities page.

 
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Arc Resistance - Concepts and Testing Explained

August 12, 2022 / by Mallory McGuinness-Hickey posted in Protection Capabilities

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Insulating materials such as Teflon, plastic, rubber, ceramic, or glass ensure products function properly and safely. However, no insulator is perfect. These materials still contain trace amounts of mobile charges that can carry current. Non-conductive polymeric coatings provide critical protection to electronic components, but these materials can become conductive when electric current travels along their surfaces due to chemical and thermal decomposition and material erosion. Therefore, the arc resistance electric property is considered when selecting materials where reliable insulation is a priority.

 

Arc Resistance Definition

Arc resistance is defined as the ability of an insulating material to withstand a high voltage, low current arc and resist the development of a conducting pathway along its surface. More specifically, it measures the time in seconds an electrical arc may exist on an insulator’s surface before the material’s breakdown occurs.  

Arc resistance coating on a PCB

Significance

This property is helpful as a design criterion to choose materials for situations vulnerable to electric arcing but serves other purposes, acting as:

  • A quality control method
  • A way to screen materials for applications susceptible to arcing
  • Determining changes in insulation behavior due to aging, irradiation, exposure to temperature or humidity, chemical and thermal decomposition, contamination, and erosion

Arc Resistance Testing

The ASTM D495 test uses a high-voltage, low-current arc to simulate service conditions and evaluate dry, uncontaminated samples. According to the ASTM D945 arc resistance test, specimens are placed between electrodes, and an arc is generated at specified current densities and scheduled intervals. The total elapsed operation time until test failure determines a material’s arc resistance.

Several arc testers that comply with this test method are commercially available.

Test Methods ASTM D 2132, D 2303, and D 3638 entail wet testing with contaminated specimens.

How to Improve Arc Resistance

Differing molecular structures, formulation ingredients such as curing agents, and physical and chemical surface conditions cause arc resistances of coatings to vary widely. Fillers, such as glass or mineral fillers, can improve the arc resistance of polymer coatings, easily doubling or tripling the arc resistance of unfilled epoxy resin systems.  

Additionally, resistance increases when the coating surface is kept dry and contaminant-free. Even touching the surface will reduce resistance due to moisture, oils, and salts transferred from the fingers.

 

Choosing The Right Coating

Not all coatings have exact arc resistance values due to issues with testing. Some crack, gum up, or melt during testing. When precise values that can be reproduced are acquired, they result from the material’s stability, purity, and surface cleanliness. If you need to evaluate material for a project, you can ask coating suppliers if an exact value is available.

Contact us or read about other critical electric thin film properties, such as volume resistivity or dissipation factor

 
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Conformal Coating for Drones - Which is Best?

April 15, 2022 / by Mallory McGuinness-Hickey posted in Thin Film Applications

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As technology advances, so do the capabilities of drones, which are available in various sizes, weights, and shapes. The technological advancements in drone specifications, mapping software, cameras, and sensory applications are expanding how different markets use these remote-controlled flying devices, increasing their prevalence.

As such, there is a growing need to improve operational endurance in harsh weather conditions and enable longer missions in unpredictable environments, as sensors within the drones that measure atmospheric parameters and gas concentrations must safely and reliably function. For example, drones operating in underground mines must be waterproof, dustproof, and shockproof and resist pressure, temperature, and humidity. Conformal coatings can meet these requirements if applied and chosen correctly.

To choose which conformal coating is best as you design drones, you will need a thorough understanding of the application environment and associated electronic reliability challenges. You must also understand the properties of each conformal coating material to determine if these properties will meet your application requirements.

Although you may not plan on considering Parylene due to perceived challenges with scalability or cost, it may be the best conformal coating for your project. The film has long been used in the aerospace industry for its exceptional properties that significantly increase electronic reliability within aircraft.

 

Beneficial Parylene Coating Properties for Drones

Parylene for drones

 

Thinner and Lighter

The coating weight you choose can be critical to battery life, with lighter films increasing your drone’s lifespan. HZO Parylene coatings have passed IPC CC-830C tests at 50% thinness of other conformal coatings, proving the coatings can provide as much, if not more, insulation flexibility, flammability, thermal shock, dielectric withstanding voltage, and moisture resistance at a fraction of the weight and mass of alternatives.

Excellent Conformality, Pinhole, and Defect-free

Parylene coatings are ultra-thin, lightweight, and due to the chemical vapor deposition (CVD) application process, the thin films are highly conformal, wrapping around every edge available. The vapor deposition process is performed under vacuum, with specialized equipment, including a coating chamber. As a result, all surfaces are coated evenly with the same thickness all around the objects being coated. This vapor phase coating process also leads to pinhole-free coverage free from defects.

Download a drone brochure

 

Beneficial Parylene Conformal Coating Barrier Properties for Drones

As aircraft that need to withstand more extreme temperature and pressure conditions encountered in aerospace applications, drones can benefit from Parylene’s impressive barrier properties, particularly those that protect electronics from the repercussions of corrosion.

Water vapor transmission rate (WVTR) and gas permeability indicate barrier effectiveness for corrosion resistance. The chart illustrates that Parylene C’s WVTR and gas permeability properties are remarkably low.

Table: Barrier Properties of Conformal Coatings

Polymer Gas Permeability at 25 °C, (cc·mm)/(m2·day·atm) WVTR,(g·mm)/(m2·day)
N2 O2 CO2 H2 H2S SO2 CI2
Parylene C 0.4 2.8 3.0 43.3 5.1 4.3 0.1 0.08
Parylene N 3.0 15.4 84.3 212.6 313 745 29.2 0.59
Parylene F (VT-4) 16.7 0.28
Epoxy (ER) 1.6 4 3.1 43.3 0.94
Polyurethane (UR) 31.5 78.7 1,181 0.93
Silicone (SR) 19,685 118,110 17,710

 

Download the HZO Parylene datasheet to find out more about Parylene Properties

Read an in-depth discussion of Parylene properties here

 

HZO Parylene Conformal Coatings for Drones

Although Parylene’s coating properties present an ideal solution to drone reliability design challenges, it has historically been used in mission-critical scenarios, such as military applications or medical implants. However, as drones become more capable and critical across markets, can you afford to compromise on your conformal coating?

Learn about all of our thin film application areas, including medical device coatings, IoT, consumer electronics, automotive coatings, and industrial coatings.

HZO is a coating supplier that makes Parylene more scalable and cost-efficient through proprietary equipment and processes. If you desire the level of reliability that Parylene can provide but are unsure if it will fit within your budget or business model, please reach out to speak to one of our Applications Engineers. Our team can evaluate your project, determine if Parylene is a suitable solution, and advise how to move forward.

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Parylene Masking - General Concepts Explained

January 28, 2022 / by Mallory McGuinness-Hickey posted in Parylene, Coating Process

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Conformal coatings are an excellent way to increase the reliability of electronic components in harsh environments. However, this protection can be too much of a good thing without processes to ensure certain areas remain coating-free.

These polymeric films can inhibit the critical functions of specific functions, but the masking process resolves this issue. With proper masking, you can benefit from conformal coating protection without losing functionality.

 

What is Masking?

Masking is applying a temporary film, boot, tape, or plug to designated assembly components to prevent them from being coated. While masking is important for conventional coatings such as acrylics, epoxies, urethanes, and silicones, Parylene has unique qualities that create a critical need to ensure it is done right.

Read about Parylene’s optical properties and Parylene biocompatibility.

 

Quick Introduction to Parylene Masking Techniques

For general guidance on conformal coating masking, the IPC-HDBK-830A handbook provides a good reference. However, because the coating process causes Parylene molecules to penetrate any surface area accessible to air, operators must ensure that all coating keep-out areas resist Parylene coating application, which requires domain expertise.

Read about Parylene C and Parylene N

HZO uses proprietary masking equipment, and our engineers build and customize techniques for every project. However, a short description of general methods follows below.

Parylene masking techniques typically involve precisely sizing materials such as tapes, form-in-place gaskets, and boots to designated masked regions. After applying materials to the appropriate areas, a masking operator will allow peelable masking materials to dry before starting the CVD process, coating the entire component. After coating, the masking material is carefully removed.

 

Why Proper Masking for Parylene Coating is So Critical

Parylene’s exceptionally high dielectric strength requires you to mask the right areas diligently. A PCBA coated with Parylene would benefit from electrical insulation protection. However, if the connectors on that same PCBA get covered, you won’t be able to plug it in or make connections.

Learn about Parylene Temperature Range

Another reason you must get your Parylene masking process correct is the film's incredible conformality. Where Parylene is allowed to penetrate, pins and moving parts will be completely encapsulated. Although this cohesive and thorough presence of coating is typically considered a benefit, additional cost and labor to remove the Parylene from the keep-out areas will be required with incorrect masking implementation. In other words, it’s best to prevent instead of rework, which can be challenging due to Parylene’s strong chemical resistance properties. 

 

Why It Can Also Be More Complicated

When you mask for Parylene application, the stakes are higher. Once it’s on, removing the coating will be a struggle without a knowledgeable partner with tools and techniques to make rework easier. The fact that masking for Parylene is also more complex, requiring more skill, raises further complications.

Without skill and experience, masking for Parylene is more challenging than general conformal coating masking due to the chemical vapor deposition process (CVD) used to apply the coating.

Learn about Parylene Thickness 

Unlike conventional conformal coatings applied as liquids, Parylene is applied as a vapor, which means you are masking against a gas. Therefore, a much better barrier is required with the Parylene masking process, as vapor can more easily bypass masking materials.

Other masking considerations include:

  • The need to validate if all components are hermetically sealed or not due to the vacuum nature of the CVD process
  • Chamber maintenance
  • Masking more than just keep-out locations may be required
  • The need for specific fixturing
  • Materials need to be thoroughly cured before coating, and outgassing should be avoided

The list below includes components that, in many cases, should not be coated:

  • MEMs
  • Actuators
  • Mating connectors and pins
  • Test points needed before assembly
  • Ground contacts

Parylene Coating With HZO

Parylene Masking with HZO

 

If you are masking for Parylene, you must implement the process correctly. Further, Parylene masking requires considerable expertise and experience to identify factors affecting masking success. These might include Parylene masking materials, the Parylene type, and the different areas that must be coated. Proper timing is also essential, as there is a relationship between the masking and coating processes. Any timing issues can impede coating quality. Managing electrostatic discharge is also a concern when masking.

Fortunately, our engineers have years of this experience, creating custom masking plans for customers with electronic products of all sizes, shapes, and functions. We have also developed industry-leading masking equipment that can automate and semi-automate the process for larger productions.

Reach out today if you would like a consultation to discuss why to use Parylene, our scalable Parylene coating equipment, or our automated masking processes that decrease Parylene coating costs

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Parylene Chemical Resistance Properties - Overview

January 21, 2022 / by Mallory McGuinness-Hickey posted in Parylene, Protection Capabilities, Coating Properties

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Choosing a conformal coating can be a complex decision that entails understanding the environment your electronic products will be operating in and taking stock of the threats to reliability associated with that environment. Will the coating need to be biocompatible? Transparent? How thick should the coating be?  

Considerations may include the operational temperature range for components and integrated circuits – will the coating you choose maintain performance throughout this range? Will your product be exposed to high levels of corrosives, humidity, or even immersion, requiring a coating with strong barrier properties? Will the environment entail exposure to various chemicals? If so, Parylene’s superior chemical resistance properties may present an ideal solution for the medical and automotive industries.

Learn more about what Parylene is used for 

 

Parylene Coating Chemical Resistance

Chemically inert Parylene conformal coatings exhibit exceptional resistance to solvents at room temperature, maintaining this property to 150° C. This resistance prevents erosion, delamination, and other minimizations of coating effectiveness, ensuring dependable performance. Additionally, Parylene coatings are highly resistant to inorganic reagents, including alkalis and strong acids.

Download HZO’s Parylene datasheet

 

Parylene coating has excellent chemical resistance to solvents and reagents, including those listed below:

Acids, Bases, Corrosives
Hydrochloric acid, 10%
Sulfuric acid, 10%
Nitric acid, 10%
Hydrofluoric acid, 10%
Sodium hydroxide solution, 10%
Ammonium hydroxide solution, 10%
Hydrogen peroxide in water (H2O2)

 

Watch Dr. Sean Clancy expand on Parylene chemical resistance in his webinar

 

Organic Solvents
n-Octane
Toluene
Chlorobenzene
Pyridine
2-Propanol (IPA)
Acetone

The exceptional chemical resistance of Parylene is one of the many beneficial properties that sustain component performance for the length of its expected lifecycle.

 

Parylene C Chemical Resistance

Parylene comes in various types, including Parylene N, C, and F (VT-4), and each type has unique properties, ensuring an appropriate Parylene for every project. Parylene C coatings specifically survive exposure to the corrosive liquids and solids mentioned above and much more. Parylene C has excellent chemical resistance to most solvents and reagents used in processing electronics and other products, including (dilute / ~10 % concentration) acids, bases, and organic solvents, such as isopropyl alcohol.

Understand how chemical resistance influences Parylene removal processes

 

Why is Parylene Chemical Resistance so High?

Parylene’s exceptional chemical resistance is partially due to the unique vacuum deposition method used to apply the coatings, chemical vapor deposition (CVD). In this vapor phase coating process, the polymer chains pack tightly against one another, making Parylene resistant to chemicals passing through the coating and reacting with the film.

Compared to liquid-derived and assembled monolayers, the chemically stronger film consistency is the source of Parylene’s chemical/solvent resistance.

 

Parylene Chemical Reaction

Typical Parylene deposition process, illustrated with Parylene N

 

Download our infographic for an illustrated guide to CVD

If you would like to learn more about Parylene coatings, please visit our Parylene page or explore one of our webinars for an in-depth discussion about Parylene delivered by one of our engineers. If you have decided Parylene is a strong choice for your application, please contact our applications engineering team today for a no-pressure consultation and understand our unique manufacturing advantages that drive down Parylene pricing

Read more about the advantages of working with HZO, including scalable Parylene coating equipment and Parylene masking automation.

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Parylene Biocompatibility Properties

January 7, 2022 / by Mallory McGuinness-Hickey posted in Parylene, Coating Properties

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As a long-proven biocompatible material, Parylene conforms to ISO-10993 and is USP Class VI implantable material. Its properties make it ideal for biological and medical applications, with additional benefits that make it a natural choice for healthcare applications. Learn more about Parylene biocompatibility and other benefits the coatings provide for medical devices.

Parylene Biocompatibility

Parylene comes in various types, including Parylene C, F (AF-4), and Parylene N, and the material has long been used as a protective medical device coating. A biocompatible material will not negatively interact with living tissue. Additionally, it is physiologically non-reactive and isn’t toxic. Parylene is chemically inert, so it can survive exposure to chemicals in and on the human body (such as implantable devices) without reacting with these chemicals.

Due to Parylene’s chemistry and structure, it is biocompatible and meets the United States Pharmacopeia’s (USP) highest standards for biocompatibility certification, Class VI standard. Parylene has passed the USP’s stringent testing process described here and has a proven track record of reliable performance in the medical device industry,

Learn more about other ways Parylene is used

 

Download the HZO Parylene datasheet

 

Benefits of Parylene for Medical Applications

 

In addition to chemical biocompatibility, Parylene conformal coating has many other properties that add value to medical devices. As a low-friction polymer coating, Parylene is a dry lubricant and allows easy sliding. Because increased friction can make a medical procedure more painful and timely, this slickness is an essential benefit for medical implants.

With a mission-critical device such as an implant, long-lasting protection against enzymes, bodily fluids, lipids, and proteins is paramount. Parylene can last for decades and has exceptional barrier properties that lead to superior corrosion resistance, excellent chemical resistance, and robust protection against liquid ingress.

Parylene is odorless and transparent, minimizing irritation, and does not require catalysts, initiators, or curing to be deposited, avoiding impurities that could disrupt its unique benefits. It also maintains protection throughout a wide temperature range

With precise control, Parylene thickness is minimal – 50% of traditional conformal coatings, with pinhole-free coatings that exhibit high dielectric strength.

 

Chemical Vapor Deposition Process

Parylene’s vapor-based deposition process creates a truly conformal, even coating desirable for applications where reliability is a priority. The highly repeatable process generates consistent results and minimizes coating defects. Several CVD services are available, including purchasing CVD equipment for sale. However, without the help of dedicated experts, endeavoring to coat your devices with Parylene can be a timely, cost-consuming process. With improper application, Parylene removal may even be necessary. 

 

Learn more about Parylene pricing

 

hzo-parylene-process-diagram-02

Illustration of the CVD Process

 

Read More about the CVD process

 

HZO Medical Coatings

As a Parylene coating company, HZO focuses on more than just producing dependable, consistent coatings. We aim to simplify the coating process with a turnkey solution, several business models, techniques,  Parylene masking automation, and Parylene coating equipment to reduce costs and make the CVD process scalable.

These benefits allow us to extend the scope of Parylene for medical devices to connected devices worn on the body, such as smartwatches, continuous glucose monitors, activity trackers, and hearing aids. With our engineers’ domain experience, we specialize in coating for the Internet of Medical Things. We believe in Parylene’s capacity to improve these critical devices that ordinarily would not be candidates for coating due to cost and scalability concerns.

If you want to speak to a team member about medical coatings, please contact us today for a consultation.

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Parylene N Properties Explained Datasheet PDF Download

December 10, 2021 / by Mallory McGuinness-Hickey posted in Parylene, Coating Properties

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Parylene is the generic name for poly-para-xylylenes. These conformal coatings come in several varieties, including Parylene C, Parylene F (VT-4), and Parylene N. Parylene properties provide superior barrier protection in the form of thin, pinhole-free coatings applied to components and devices to sustain product life and bolster reliability. Parylene is biocompatible and complies with REACH, RoHS, and Prop 65.

Learn more about what Parylene is used for

 

Parylene N Properties

Parylene N has the highest dielectric strength of the Parylenes, has a melting point of 420°C (or 788°F), and is a commercially available halogen-free Parylene. To see the properties of Parylene N, you can view the HZO Parylene datasheet below, under the column of HZO Zero™, our Parylene N offering, and read a short description of notable Parylene properties. (For reference, HZO Guardian Plus™ is our Parylene C coating solution, ideal for corrosion resistance).

You can also download the datasheet:


Parylene Mechanical and Physical Properties

 

Parylene has a relatively high yield and tensile strength compared to other polymer coatings, with substantial wear resistance. In general, Parylene provides superior mechanical protection.

 

Parylene N Young’s Modulus

Young’s modulus measures the stiffness of solid material or resistance to elastic deformation. The values for Tensile Strength and Young’s Modulus for Parylene N and C can be found below, as well as for polyester and polyamide.

 

Table 1: Young’s Modulus and Tensile Strength for Parylene C and N and Polyester and Polyamide

Material Young’s Modulus Tensile Strength
Polyester 7.1×105 psi MD 29,000 psi MD
Polymide 3.6×105 psi ~33,500 psi
Parylene C 4.6×105 psi 10,153 psi
Parylene N 3.5×105 psi 6,526 psi

 

 

Parylene Electrical Properties

Parylene is a superior electrical insulator with excellent uniformity, and the pinhole and defect-free coverage help the coatings prevent arcing. Although the insulating properties of the Parylene increase with thickness, they are defined by the fundamental composition of the coating. Each type of Parylene has different properties, and by selecting a specific thickness and type, you can fine-tune electricity-blocking properties.

 

Parylene Dielectric strength

Dielectric strength is the maximum voltage required to produce a dielectric breakdown through the coating material, expressed as Volts per unit thickness. This is an essential property for higher voltage design, as it protects against high voltage from static electricity and arcing.

 

Read more about Parylene’s optical properties

 

Parylene Thermal Properties

Read more about Parylene temperature range

Like all materials, Parylene coatings degrade as the temperature increases but have high melting points. The temperature stability values for the Parylenes are listed in the table below.

Table 2: Parylene Thermal Properties

Parylene Type

Long-Term Temperature Limit (°C)

Duration=~10+ Years

Short-Term Temperature Limit (°C)

Duration=~1 Month

Melting Point Temperature (Tm)
Parylene N 60 96 420
Parylene C 80 115 290

 

Read more about Parylene Removal 

 

Parylene Barrier Properties

Parylene coatings provide an excellent physical barrier protecting the coated components from electrical shorting and external contamination. The coating blocks gases that can lead to corrosion of the coated object and serves as a physical barrier to protect from sources of contamination, including foreign object debris (FOD), dust, airborne salts, and metal filings. Parylene also has exceptional chemical resistance with a chemical barrier layer. 

Gas permeability and water vapor transmission rate (WVTR) are important properties for evaluating corrosion resistance; the lower, the better. The table below illustrates these properties in Parylene and other conformal coating materials.

 

Table 3: Barrier Properties of Conformal Coatings

Polymer Gas Permeability at 25 °C, (cc·mm)/(m2·day·atm) WVTR,(g·mm)/(m2·day)
N2 O2 CO2 H2 H2S SO2 CI2
Parylene C 0.4 2.8 3.0 43.3 5.1 4.3 0.1 0.08
Parylene N 3.0 15.4 84.3 212.6 313 745 29.2 0.59
Parylene F (VT-4) 16.7 0.28
Epoxy (ER) 1.6 4 3.1 43.3 0.94
Polyurethane (UR) 31.5 78.7 1,181 0.93
Silicone (SR) 19,685 118,110 17,710

 

Watch Dr. Clancy’s webinar on proven methods of corrosion resistance

About HZO

HZO is focused on increasing coating efficiency and driving down Parylene costs. We provide scalable Parylene equipment and automated Parylene masking to save time and labor within our turnkey solution. Contact us today if you are considering Parylene for your application and want to speak to an engineer.

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How to Make Your Lithium-ion Battery Design More Sustainable

December 4, 2021 / by Mallory McGuinness-Hickey posted in Thin Film Applications

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A recent report from “Markets and Markets” revealed that experts expect the battery recycling market to grow to $23.2 billion by 2025, at a CAGR of 6.1% from 2020-2025.

This market focused on recycling batteries encompasses many industries and various battery chemistries, including lead-acid batteries, lithium-ion (Li-ion) batteries, and nickel-based batteries. The impetus for this market growth includes sustainability regulations that strive to preserve resources, reduce carbon footprint, and restore soil integrity.

Although data indicate a demand for responsible afterlife handling of batteries, complications can arise for Li-ion energy sources, raising concerns for product designers.

Lithium-ion Battery Disposal and Recycling Issues

Manufacturers value Li-ion batteries for benefits such as low self-discharge, low “memory” (the tendency to acquire a minimum or maximum state of charge), and high energy density. However, they have volatile chemistry that requires regulating their disposal on both state and federal levels.

Processes used to recycle lithium-ion batteries have merit because they can regain valuable metals from spent battery cells, including nickel, cobalt, copper, and aluminum. However, there are dangers associated with recycling processes, including thermal, chemical, and electrical hazards due to the potential for chemical reactions.

 

Designing Longer-Lasting Li-ion Batteries Can Be Part of the Solution

While no definitive, universally accepted solution exists to make lithium-ion batteries easier to handle after they no longer work, product designers can use Parylene coatings to prevent premature failure and encourage Li-ion resiliency despite exposure to failure-inducing situations. With the ability to extend product life and discourage unnecessary loss using a sustainable coating solution, you can do your part to comply with sustainability guidelines and reduce waste.

Download HZO’s Battery Coating Brochure

 

How Parylene Reduces Unnecessary Lithium-ion Waste

 

Corrosion Resistance for Li-ion Batteries

A Parylene provider can strategically coat critical components of Li-ion batteries without interfering with their operation. The thin coating can act as a barrier layer, hindering the devastating consequences of corrosion and premature failure caused by corrosive environments.

Watch our webinar on proven methods of corrosion resistance.

 

Parylene is particularly effective at protecting Li-ion batteries from corrosion. Its water vapor transmission rate (WVTR) and gas permeability, which indicate barrier effectiveness for corrosion resistance, are particularly low.

Polymer Gas Permeability at 25 °C, (cc·mm)/(m2·day·atm) WVTR,(g·mm)/(m2·day)
N2 O2 CO2 H2 H2S SO2 CI2
Parylene C 0.4 2.8 3.0 43.3 5.1 4.3 0.1 0.08
Parylene N 3.0 15.4 84.3 212.6 313 745 29.2 0.59
Parylene F (VT-4) 16.7 0.28
Epoxy (ER) 1.6 4 3.1 43.3 0.94
Polyurethane (UR) 31.5 78.7 1,181 0.93
Silicone (SR) 19,685 118,110 17,710
Ref.: Licari, James J. Coating Materials for Electronic Applications – Polymers, Processes, Reliability, Testing. William Andrew Publishing, 2003 and various companies’ literature.

 

The images below indicate the appearance of coin cell batteries, one exposed to salt water testing, one representing an HZO-coated battery appearance.

 

Figure 1 – Uncoated coin Cell battery subjected to salt water testing

 

Figure 2 – Image of what an HZO Parylene coated battery subjected to saltwater testing would look like

 

Heat Dissipation Properties of Parylene

Although lithium-ion batteries require protection from corrosives, when coatings (such as conventional coatings that require more coating to attain a suitable protection level) are applied in thick layers, this can interfere with the heat transfer path, impeding heat dissipation. As thermal conduction is inversely proportional to thickness, integrating the thinnest possible coating solution can prevent overheating, a serious reliability challenge for Li-ion batteries. HZO Parylene can provide superior corrosion resistance at 50% film thinness of conventional conformal coatings, meeting protection and heat dissipation challenges.

 

Parylene Will Withstand the Life of the Lithium-ion Batteries It Protects

 

When Li-ion batteries are stored for a long time, they become more susceptible to damage as they are exposed to environments with harmful elements. HZO’s coatings can sustain through the product lifecycle, averting common battery e-waste issues.

 

Table 3: Lifetime of HZO coatings at different temperatures in air (with oxygen)
  60 °C 80 °C 135 °C 150 °C
Parylene C ~100 years ~20 years ~70 hours ~24 hours
Parylene N ~10 years ~1 years ~9 hours ~1 hour

 

HZO Coatings for Lithium-Ion Batteries

As a green manufacturer, HZO focuses on inherently sustainable solutions that comply with REACH, RoHS, and Prop 65 and eliminate cure time. With Parylene, there are:

  • No VOCs
  • No Solvents
  • No Catalysts
  • No Disposal Issues
  • No Pollution Threats

If you want to learn more about the manufacturing advantages of working with HZO, contact us today to speak with an engineer.

 
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Improving CGM Electronics Designs with Medical Coatings

November 20, 2021 / by Mallory McGuinness-Hickey posted in Thin Film Applications

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A vital issue for continuous glucose monitor development is design and reliability engineering. 

CGM systems, however, will encounter environments that can jeopardize electronics that enable functions, such as sensors, making validation of actual product use difficult. The human body will subject CGMs to perspiration and other bodily fluids, vibration, shock, and the potential for drops.

Additionally, regular use presents threats in varied environments as users always wear the products in various settings. CGM devices are more valued by people with diabetes when they enable ease of use. Using continuous glucose monitoring systems in showers, harsh weather conditions, swimming pools, and humid conditions is often a purchase contingency.

Therefore, the ability to operate reliably through frequent exposure to chemicals and corrosives, including airborne pollution, cleaning fluids, soap, and hygienic products, is a critical feature that, if underestimated, can increase product recalls, repairs, and warranty claims.

CGM technology has exponentially evolved, but it is up to product design teams to evaluate if they are genuinely validating actual product use. If you are a CGM product designer and feel your products are experiencing reliability issues, coating systems, particularly Parylene conformal coatings, may be worth investigating.

Watch our webinar “Design for Reliability.”

 

Corrosion Resistance is a Mandate for CGM Reliability

 

CGMs, like all electronic devices, run on electricity and batteries. Without proper protection, one drop in the water can kick off the corrosion process, catalyzing unexpected, premature failure. Parylene’s superior corrosion resistance is one compelling reason to use this CGM coating.

Performing as a barrier to corrosion caused by moisture, biofluids, submersion, and cleaning fluids, Parylene minimizes the impact of factors that affect coating performance and lifetime, including the following:

● Low oxygen permeability for a protective polymer coating
● Minimal absorption of water
● Ionic permeability makes it difficult for salts to pass through the coating
● Parylene’s characteristic pinhole-free coatings

Gas permeability and Water Vapor Transmission rate indicate barrier effectiveness for corrosion resistance; the lower, the better. The chart below illustrates these properties compared to other conformal coatings.

Download HZO’s Parylene datasheet

 

Polymer Gas Permeability at 25 °C, (cc·mm)/(m2·day·atm) WVTR,(g·mm)/(m2·day)
N2 O2 CO2 H2 H2S SO2 CI2
Parylene C 0.4 2.8 3.0 43.3 5.1 4.3 0.1 0.08
Parylene N 3.0 15.4 84.3 212.6 313 745 29.2 0.59
Parylene F (VT-4) 16.7 0.28
Epoxy (ER) 1.6 4 3.1 43.3 0.94
Polyurethane (UR) 31.5 78.7 1,181 0.93
Silicone (SR) 19,685 118,110 17,710
Ref.: Licari, James J. Coating Materials for Electronic Applications – Polymers, Processes, Reliability, Testing. William Andrew Publishing, 2003 and various companies’ literature.

 

Watch our webinar on proven methods of corrosion resistance.

Submersion Protection Enables You to Meet any Liquid Ingress Protection Standards

 

As CGM consumers often base purchase decisions on the ability to meet IP ratings, it might be necessary for your team to meet a particular IP standard. HZO Parylene coatings have been tested for over 1,000 hours of submersion, providing a proven method to meet any IP protection level quickly and conveniently.

Download the HZO IP checklist

 

Environmentally Friendly Solution with Green Manufacturing Support

Sustainability policies and regulations can have far-reaching effects on your decisions, ranging from material selection through the manufacturing process. The Parylene polymerization process simplifies sustainability, as there are none of the following complications that can inhibit compliance:

  •  No VOCs
  •  No Solvents
  •  No Catalysts
  •  No Disposal
  •  No Pollution Threats

HZO’s Parylene coatings are:

  • RoHS Compliant
  • REACH Compliant
  • Prop 65 Compliant

As a green manufacturer, HZO’s support includes the following:

  • Material oversight
  • Corporate social responsibility
  • Green material usage
  • Preparation for repair, reuse, and recycling
  • Proactive chemical management
  • Responsible end-of-life management

 

Simplify Design With Parylene's Thinness

HZO Parylene passed IPC CC-830C at 50% thinness of conventional conformal coatings, proving no other coating can perform as well in terms of chemical, moisture, and biofluid barrier properties at its thinness.

Parylene can also provide dielectric barrier protection without signal transfer or loss. Furthermore, its low dielectric constant ensures minimal energy loss in RF signals, and the coating thinness ensures signal transmission integrity. The chart below illustrates suitable Parylene thickness for various applications:

 

Thickness(μm) Relevant Standards IP Protection Level
0.1 to 5 UT Type in IPC-CC-830C IPX3/IPX4
5 to 12.5 UT Type in IPC-CC-830C IPX4/IPX7
12.5 to 25 IPC-CC-830B IPX7/IPX8

 

Choose HZO for CGM Coatings

With CGM experience, our engineering team knows how to create business-specific solutions that ensure your product will work in the real world. HZO has eliminated many barriers to Parylene on the manufacturing end by developing cost-cutting equipment that can quickly scale as your business grows. If you want to meet with our applications engineering team for a DFM consultation, reach out today.

 
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Developing Health Wearable Devices That Work in the Real World

November 5, 2021 / by Mallory McGuinness-Hickey posted in Thin Film Applications, Value of Coatings

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Smart wearable medical device designers must create flexible, lightweight, low-profile, comfortable electronic products that enable constant, real-time data transmission. The data is critical, medical in nature, with the potential to save lives. Considering these challenges, it is easy to acknowledge that wearable wireless medical devices are difficult to design, and the process is iterative.

Health wearable environments are often harsh; therefore, their packaging and protection play a critical role. Electronic and mechanical requirements are equally vital and must be adequately protected. If the medical wearable isn’t functional, it won’t sell. As such, many engineers feel that the overwhelming design concern for these products comes down to packaging and protection.

 

Two Critical Medical Wearable Design Challenges to Consider When You Think About Protecting Electronic Components

Whether you feel that packaging and protection is a priority or not, the measures you take to ensure your wearable medical device technology is sufficiently resilient can affect two other critical wearable design challenges.

1. Component Miniaturization and Space Optimization

Bulkier, larger, wearable medical devices were initially developed for clinical environments, but as telehealth trends continue, medical wearables are now worn outside the hospital. This change in context requires a more compact, comfortable product with lighter-weight, smaller components and a need for enhanced design flexibility. Space optimization is an essential design consideration as various technologies and provisions for more communication circuits must be incorporated – within a tighter footprint.

2. Signal Integrity

Wearable medical tech requires comfort, aesthetics, and ease of use. Still, the primary purpose of the technology is to relay patients’ health data accurately and quickly to healthcare providers, making high signal integrity an integral goal. Additionally, these devices require bidirectional data streams, so informational flow is essential too.

 

When Design Priorities Clash with Electronic Protection Methods

Legacy protection and packaging methods used in the past to bolster reliability can interfere with other design efforts. For example, highly customized enclosures incorporating many seals can be too cumbersome for consumers’ comfortable, compact devices. Similarly, conventional conformal coatings often require thick layers of protection that can impede signal integrity.
Unfortunately, medical wearables must dependably operate when worn on the body, requiring protection from drops, vibration, moisture, corrosion, humidity, perspiration, sterilization, and many other damaging environmental elements. This need is non-negotiable and can incur costs associated with warranties, recalls, liability, and product returns when unmet.

Download the HZO Parylene datasheet.

 

Consider Parylene to Improve the Design of Medical Wearable Products

 

HZO focuses on solving product design challenges and provides an alternative material solution to conventional coatings and seals that can provide superior protection without impeding signal integrity, comfort, or miniaturization. Whether used with customized enclosures as redundant protection or alone, our Parylene coatings offer the required protection while enabling you to meet other design goals.

 

Protection Capabilities

Considering environmental hazards ahead of time can enhance material choice, and there are two types of environments to consider. The outside environment can present challenges such as humidity, submersion, pollution, cleaning fluids, corrosive liquids and gases, and the human body, which includes perspiration and other bodily fluids. Sweat is very slippery, allowing for ingress through mechanical seals, and humidity is another challenge for this method, as it can also enter and begin corroding components. Additionally, one environment can affect the other. For example, humid climates may produce more sweat and make skin dewier.

Water vapor transmission rates (WVTR) can aid in predicting coating behavior in high-moisture environments, offering help in the material selection process. The chart below illustrates the WVTRs of Parylene compared to other conformal coatings. The lower the WVTR, the better.

 

Polymer Gas Permeability at 25 °C, (cc·mm)/(m2·day·atm) WVTR,(g·mm)/(m2·day)
N2 O2 CO2 H2 H2S SO2 CI2
Parylene C 0.4 2.8 3.0 43.3 5.1 4.3 0.1 0.08
Parylene N 3.0 15.4 84.3 212.6 313 745 29.2 0.59
Parylene F (VT-4) 16.7 0.28
Epoxy (ER) 1.6 4 3.1 43.3 0.94
Polyurethane (UR) 31.5 78.7 1,181 0.93
Silicone (SR) 19,685 118,110 17,710
Ref.: Licari, James J. Coating Materials for Electronic Applications – Polymers, Processes, Reliability, Testing. William Andrew Publishing, 2003 and various companies’ literature.

 

Watch Dr. Sean Clancy’s webinar on proven methods for protection from corrosive environments.

 

Parylene is also known for strong submersion protection, and HZO Parylene has been tested beyond 1,000 hours of submersion. As Ingress Protection (IP) claims can influence consumer purchasing behavior, our coatings offer value. Our tested, proven solution can meet any IP claim without the need for excessive enclosure customization and subsequent trips to the lab for testing.

 

Miniaturization

Our Parylene conformal coatings have passed the IPC CC-830C test at 50% of the film thickness of conventional conformal coatings. The data prove that our coatings can provide as much – or more – flexibility, fungus resistance, flammability, dielectric withstanding voltage, thermal shock, moisture, and insulation resistance at a fraction of the mass.
With thinness ranging from 2-50 microns, Parylene still outperforms other coatings regarding corrosion resistance, ensuring that you can produce robust, dependable medical products that can still be miniaturized.

Additionally, the thinness of the coatings ensures reliable signal transmittance will not be a problem.

 

How HZO Does Parylene Differently

 

Image of low cost Parylene equipment

 

Parylene conformal coatings come in various types, including Parylene C, Parylene N, and Parylene F (VT-4). The coating is superior in uniform coverage, barrier properties, and performance at comparably thinner films, with less stress on mechanical structures and virtually no added weight. Due to its properties, Parylene has been trusted for decades in the medical industry to safeguard implants and other critical devices. As HZO has engineered processes that cut costs and allow easy ramp-up to mass production with proven Parylene coatings, it may be time to revisit this solution for less-invasive medical products.

We address the cost concerns and batch-style coating process associated with Parylene through engineering and manufacturing solutions – we can rise to mass-scale production within a specified budget or deadline. Our throughput can be two times faster than the industry standard with our in-house designed equipment, tested processes, and chemistry.

Proprietary equipment with optimized cubed chambers can house more substrates and components than any other Parylene supplier, decreasing turnaround time, improving throughput, and decreasing costs associated with coating runs. The chambers are larger in size, but the cubed shape also allows for high loading density so that not as much surface area is lost. The numbers of parts coated for medical devices vary, but HZO’s manufacturing process allows for efficient high throughput. For reference, around 10,000 – 20,000 hearable device components or batteries may be coated in a single batch.

Our engineers are here to help you meet product requirements and prepare your medical wearables for long-term business success. Their prescriptive solutions can allow you to achieve the functions and features your product must have to offer a successful outcome. If you have questions for our team or would like a no-obligation DFM consultation, contact us today.

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How Much Does Parylene Coating Cost? - All Things Considered

October 15, 2021 / by Mallory McGuinness-Hickey posted in Parylene, Value of Coatings

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Parylene coatings are known for robust protection from liquids, corrosion, chemicals, and strong electrical activity at a fraction of the thickness of alternative coatings, such as acrylics, epoxies, silicones, and urethanes. Additionally, Parylene is biocompatible, with beneficial optical properties, and delivers superior protection at 50% thickness of conventional coatings, such as acrylic conformal coating or epoxy. However, the perceived cost of Parylene dimer and Parylene labor costs, compared to other conformal coatings, can give design teams hesitation as they consider incorporating high-reliability protection into their project.  

Read about what Parylene is used for

 

Is Cost-Efficient Parylene Possible?

 

Despite its proven performance, many perceive Parylene coating as challenging and expensive to apply. Therefore, one assumption is that it is only appropriate in extreme mission-critical situations, such as military, medical, or aviation applications. Other common misconceptions about Parylene include the following:

  • Reworking and removing Parylene is impossible
  • Parylene coating equipment is too expensive and complicated to use
  • Masking is too complex and time-consuming to bother with
  • CVD coatings (chemical vapor deposition) entail long batch times leading to higher labor costs and low throughput

Although these assumptions are unfounded, it is a fact that Parylene coating is typically the most costly of all conformal coating options. As a result, it's important to choose a partner who can work within your budget constraints and assist you in estimating potential expenses.

 

How to Calculate the Cost of Parylene

 

HZO capital equipment being used to lower Parylene coating cost

 

At HZO, we have crafted processes and procedures to lower the costs of the Parylene coating processes. However, three factors are pertinent to the price regardless of whom you work with.

 

Parylene Type

 

Common varieties, such as Parylene C and Parylene N, are less costly in raw coating material known as Parylene dimer. “Specialty types” such as Parylene-AF4 will cost more but will enable better performance in terms of UV and heat resistance. A consultation with a Parylene conformal coating services provider, such as HZO, will help you determine which Parylene type is most suitable for your project.

 

Masking

 

Masking can be more complex with Parylene coatings, resulting in increased labor. However, altering the design of your product can make it easier to coat and mask, reducing associated costs. HZO has industry-leading automated and semi-automated masking and demasking equipment, simplifying the process and reducing expenses should you choose to work with us.

 

Quantity and Size of Objects that Require Coating

 

With Parylene, the objects you need to coat are placed into a vacuum chamber as part of the chemical vapor deposition (CVD) coating process, and each coating run will have a fixed cost. However, you can optimize the number of components coated in each run to lower the coating cost per item. Meanwhile, we have built proprietary coating equipment that can house more items at once per coating run than any other Parylene company in the industry, minimizing costs per coating run.

 

Other Critical Considerations When Evaluating Parylene’s Price

 

Aside from considering upfront costs, to accurately assess Parylene’s coating expense, you must consider the coating’s value in terms of performance to preserve product function over time. In other words, the total cost of ownership is a critical consideration – upfront coating expense cannot fully measure value over a product’s life cycle. Parylene’s superior conformality and protection capabilities dramatically reduce field failures, warranty costs, and downtimes.

When you take the long-term view, the productivity and warranty savings that Parylene provides over time can make it the most economical coating option. There are other savings to consider when evaluating the price of conformal coatings, such as manufacturing costs. Conventional coatings entail cure cycles, VOC emissions, toxic byproducts, flammability, waste disposal, and health concerns. Parylene does not raise these safety and sustainability concerns as an environmentally friendly process.

Finally, investing in Parylene, with its exceptional dielectric strength, chemical and moisture resistance, and stress-free encapsulation, can substantially reduce the TCO to ruggedize components compared to other options.  

Want to ensure HZO Parylene meets your specifications?

 

HZO Parylene Conformal Coating Services

 

If you are interested in Parylene coatings and want to evaluate upfront costs and potential savings, contact one of our experts for a no-obligation DFM consultation.

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Parylene C Datasheet (PDF Download) - Properties Explained

August 20, 2021 / by Mallory McGuinness-Hickey posted in Parylene, Coating Properties

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Parylene conformal coatings come in various types, including Parylene C, Parylene N, and Parylene F (VT-4), with decades of trusted performance in critical industries and applications. The coating is often superior in barrier properties, uniform coverage, and performance, with less stress on mechanical structures, as a Parylene datasheet indicates.

Parylene coatings have good optical properties, are comparably thinner than conventional conformal coatings, and add virtually no weight to components and products. Parylene’s coating thickness can pass tests such as IPC CC-830C at 50% of the film thickness of other conformal coating materials.

Parylene coatings are unique in their ability to be polymerized and deposited by chemical vapor deposition (the Parylene coating process) onto components maintained at room temperature. As a result, the coatings are high purity, free of defects and pinholes, and ideal for meeting many electronic product design reliability requirements.

Parylene C is biocompatible, highly resistant to moisture, vapor, and corrosive gasses, and exhibits strong chemical resistance. Because of these strong anti-corrosion properties and a valuable combination of properties for most applications, from medical devices to personal computers. Parylene C is used for most products that need a conformal coating for protection.

Learn more about why Parylene is used

To see the specific properties of Parylene C, you can download HZO’s Parylene datasheet below, under the column of HZO Guardian Plus™, our Parylene C offering. For reference, HZO Guardian Zero™ is our Parylene N coating solution, suitable for halogen-free applications.

Download HZO’s Parylene datasheet.

 

For reference, a short description of each category property in the Parylene datasheet is provided, as well as some descriptions of tests used to acquire data and explanations as to why some data points might be vital for your application.

Parylene Physical and Mechanical Properties

 

Parylene is a crystalline polymer that results in generally high mechanical strength. Compared to other polymer coatings, it has a relatively high tensile and yield strength, with substantial wear resistance. An explanation for some Parylene datasheet properties is below.

 

Parylene C Young’s Modulus

 

Young’s modulus is a mechanical property that measures the stiffness of a solid material. Young’s modulus is the elongation of a material under unit stress when the deformation is elastic.

The image below depicts an example stress-strain curve which shows the change in stress as strain increases and identifies Young’s modulus and Tensile strength

Young’s modulus is the slope of the linear part of the stress-strain curve for a material under tension or compression. In other words, the strain will be proportional to stress. There is no permanent deformation either. The material will behave like a spring and return to its original dimension upon removing load.

Tensile strength is the maximum stress a material can withstand. Meanwhile, Elongation to Break is the ratio between the changed length and the initial length after the breakage of test specimen.

Parylene Young's Modulus

Image Source: https://www.thefabricator.com/thefabricator/article/metalsmaterials/the-differences-between-stiffness-and-strength-in-metal

 

The table below shows values for Young’s Modulus and Tensile Strength for Parylene C and N and polyester and polyamide.

 

Table 1: Young’s Modulus and Tensile Strength for Parylene C and N and Polyester and Polyamide

Material Young’s Modulus Tensile Strength
Polyester 7.1×105 psi MD 29,000 psi MD
Polymide 3.6×105 psi ~33,500 psi
Parylene C 4.6×105 psi 10,153 psi
Parylene N 3.5×105 psi 6,526 psi

 

Parylene C Electrical Properties

 

Parylene doesn’t conduct electricity, an essential trait for a film that coats and separates conductive areas on electronics. As the Parylene datasheet indicates, it is a superior electrical insulator (dielectric) coating since it coats every surface on a product with uniform thickness. Although conformal coatings aren’t meant to be used as the primary means of electrical insulation, they can isolate electrical ground from active traces and supplement other insulation forms. The lack of pinholes and other point defects helps Parylene prevent arcing.

A coating with variable thicknesses on an electronics assembly running at high voltage may have a greater risk of failure if the device operates near the dielectric breakdown voltage of the coating. The coating undergoes a complete failure at the breakdown voltage, and any insulative properties are left negligible or lost entirely.

An example of how Parylene deposits is depicted below:

Parylene Deposition

Courtesy of CALCE, University of Maryland

 

Though defined by its fundamental composition, the insulating properties of a Parylene coating increase with thickness. By selecting a specific Parylene thickness, you can fine-tune electricity-blocking properties. Since each Parylene type has different dielectric properties, there’s a suitable parylene for virtually every application.

 

Parylene Dissipation Factor

The dissipation factor is the reciprocal ratio between the insulating material’s capacitive reactance to its resistance (Equivalent Series Resistance or ESR) at a specified frequency.

This property measures electrical energy lost and absorbed (power dissipation) when an electrical current is applied to an insulating material. Much of the absorbed energy is dissipated as heat—the lower the dissipation factor, the more efficient the insulator system. Dissipation factor is an essential property because it can be used to maximize power delivery.

 

Parylene Dielectric Strength

Dielectric strength is defined as the maximum voltage required to produce a dielectric breakdown through the material and is expressed as Volts per unit thickness. The image below shows that the original dielectric material as an insulator becomes a conductor because the dielectric material passes the maximum voltage and produces a dielectric breakdown.

Parylene Dielectric Strength


Dielectric strength is important for higher voltage design because it prevents arcing and protects against high voltage from static electricity. Please refer to the Parylene datasheet to see the values for this property.

 

Learn about Parylene removal considerations.

 

Parylene C Dielectric Constant

Dielectric constant is the ratio of the permittivity of a substance to the permittivity of free space.

 

Dielectric Constant (k) = ε / ε0

Parylene Dielectric Constant

A sample is placed between two metallic plates, and capacitance is measured to obtain these values. A second run is measured without the specimen between the two electrodes. The dielectric constant is the ratio of these two values, and a low dielectric constant is essential for rapid signal propagation.

 

Parylene Thermal Properties

Parylene coatings have temperature limits that, when reached, shorten the coating’s usefulness. You must know your expectations and/or specifications for the product’s end-use environment to mitigate risks associated with high-temperature applications. The temperature stability values for the parylenes are collected in the table below and are based on industry literature.

 

Table 2: Parylene Thermal Properties

Parylene Type Long-Term Temperature Limit (°C)

 

Duration=~10+ Years

Short-Term Temperature Limit (°C)

 

Duration=~1 Month

Melting Point Temperature (Tm)
Parylene N 60 96 420
Parylene C 80 115 290

 

Fortunately, the Parylene C melting temperature is high, at 290 °C. Parylene N maintains performance through even more extreme temperatures.

Read more about Parylene temperature range

 

Parylene Barrier Properties

Parylenes are hydrophobic, ultrathin, lightweight, and highly conformal, wrapping around every edge available, where the coating deposits the same thickness around the components they coat. The vapor phase coating process leads to pinhole-free coatings that are also defect-free. In addition, the coatings trap and immobilize any particles that may be present on substrates.

The polymer chains pack tightly against one another, making Parylene resistant to chemicals passing through the coating and reacting with the coating itself. Parylene is impervious to moisture and insoluble in chemicals found in most end-user and industrial environments. The coating also does a good job of blocking gases that can lead to corrosion of the coated object.

The Parylenes provide an excellent physical barrier that protects the underlying objects, especially electronics, from external contamination and electrical shorting. As a physical barrier, Parylene protects from various types of problematic contamination, such as dust, foreign object debris (FOD), metal filings, and airborne salts.

Parylene C has the best barrier properties, as indicated on the Parylene datasheet, including preventing gas and water vapor penetration. The table below compares the Gas Permeability and WVTR of Parylene with other conformal coating materials.

Table 3: Barrier Properties of Conformal Coatings

Polymer Gas Permeability at 25 °C, (cc·mm)/(m2·day·atm) WVTR,(g·mm)/(m2·day)
N2 O2 CO2 H2 H2S SO2 CI2
Parylene C 0.4 2.8 3.0 43.3 5.1 4.3 0.1 0.08
Parylene N 3.0 15.4 84.3 212.6 313 745 29.2 0.59
Parylene F (VT-4) 16.7 0.28
Epoxy (ER) 1.6 4 3.1 43.3 0.94
Polyurethane (UR) 31.5 78.7 1,181 0.93
Silicone (SR) 19,685 118,110 17,710
 
Ref.: Licari, James J. Coating Materials for Electronic Applications – Polymers, Processes, Reliability, Testing. William Andrew Publishing, 2003 and various companies’ literature.

 

Parylene C also performs well when immersed in solutions of sodium chloride salt in water. The following table shows Parylene C’s performance compared to examples of epoxy, polyurethane, silicone, and Teflon™ coatings.

Table 4: Resistance of Different Polymers to 0.9% Saline Solution

Polymer Coating Method Layer Thickness (microns) Time Until Total Breakdown
Parylene C 60 25 > 30 d
Epoxy (ER) 80 100 ± 25 6 h
Polyurethane (UR) Dip Coating 100 ± 12.5 6 h
Silicone (SR) Dip Coating 75 ± 12.5 58 hr
Teflon Spraying 75 6 h
 
Ref.: Mordelt, G., Heim, P. High-Tech-Beschichtung der Zukunft, Metalloberfläche 52(5), 368 − 371 (1998).

 

In general, Parylene C performs extremely well as a barrier to corrosion due to the coating’s ability to minimize the influence of the factors that affect coating lifetime and performance, including the following:

  • Oxygen permeability − low oxygen permeability for a polymer coating
  • Water vapor permeability − very low WVTR for a polymer coating
  • Liquid water uptake − Parylene C absorbs very little water
  • Ionic permeability − salts have a difficult time passing through the coating
  • Coating porosity − at a thickness of just 5 to 8 microns, Parylene C forms a pinhole/pore-free coating

Watch Dr. Clancy’s webinar on proven methods of corrosion resistance

 

About HZO

HZO is a Parylene services provider focusing on driving down associated costs and increasing coating efficiency for Parylene’s solvent-free deposition method. We have built proprietary cubed Parylene chambers that can house more substrates than any other Parylene company. Our chambers are large in size, but the cubed shape allows for high loading density, increasing throughput, and scaling for high-volume applications.

We have also built equipment to automate Parylene masking and demasking to cut costs, save on labor, and decrease the risk of quality issues due to manually doing these processes.

To learn about Parylene pricing for your next project, contact us today. To learn about our proven track record, read our case studies.

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How to Remove Conformal Coating - Which Method is Best?

June 17, 2021 / by Mallory McGuinness-Hickey posted in Conformal Coatings, Coating Process

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Conformal coatings are polymeric films applied directly to PCBAs and electronic components to provide a barrier layer of protection from the environment in which they operate. There are five primary conformal coating materials: acrylics, epoxies, silicones, urethanes, and Parylene. Each material presents its advantages, limitations, challenges, and application methods.

Learn about conformal coating application methods

Acrylic (AR) Conformal Coating Properties

  • Low moisture absorption
  • Relatively short drying times
  • Clear protective coating
  • Good electrical and physical properties
  • Typically brushed, sprayed, or dipped

Epoxy (ER) Conformal Coating Properties

  • Very robust
  • Excellent chemical and abrasion resistance
  • Very rigid conformal coating
  • High dielectric strength
  • Typically brushed, sprayed, or dipped

Read more about epoxy conformal coating

Silicone (SR) Conformal Coating Properties

  • Good humidity and moisture resistance
  • Low toxicity
  • Easy to apply
  • Easy to repair
  • Typically brushed, sprayed, or dipped

Read more about conformal coating application

Properties of Urethane (UR) Conformal Coatings 

  • Moisture and oil-resistant
  • Fungicidal
  • Good flexibility
  • Can be thinned to achieve a chosen viscosity
  • Typically brushed, sprayed or dipped

Read more about polyurethane conformal coating

Properties of Parylene (XY) Conformal Coatings

  • Biostable, biocompatible
  • Excellent chemical resistance
  • Superior conformality
  • Exceptional corrosion resistance
  • Applied by chemical vapor deposition (CVD)

Understand conformal coating vs potting

engineer looking at PCB to determine how to best remove conformal coating

Read the definitive paper on electronic protection methods

Every so often, conformal coatings must be removed. This may be for several reasons, including electrical or functional failures that require rework, PCBA malfunctions, initial design process issues, poor adhesion, conformal coating defects, or improper choice of coating material. Whatever the reason, the first step in the removal process is to determine which coating material you are working with, as this will help determine how to remove the PCB coating.

 

How to Remove Conformal Coating

Confirm the coating material applied to the PCB you want to remove to determine the best conformal coating method. Confirmation can typically be achieved by either contacting your coating supplier or looking for a JEDEC or IPC label placed on the board. Coatings are designated as AR, SR, ER, UR, or XY, indicating with which coating you are working. If there are no labels, you can still ID the material via methods outlined by the IPC below.

Because each conformal coating has distinct properties, methods such as testing transparency, solubility, hardness, thermal removal, and thickness can show you which type of coating you are working on. For more information, see IPC’s “Coating Removal, Identification of Conformal Coating” guidelines.

 

Conformal Coating Removal Techniques

After identifying your coating, the next step is to choose the removal technique. Popular methods are briefly discussed below:

Peeling Method

Typically used for RTV silicone or thick rubber coatings, use a dull blade or knife to slit the coating material and peel it off.

Chemical Solvent Method

This process effectively removes urethane, acrylic, and silicone coatings. Prep the area with high-temperature tape and apply solvent using a foam swab.

Grinding and Scraping Method

This removal technique can grind away thin, hard coatings with a micro motor or rotary-style tool or soft coatings with a rotary brush.

Thermal Method

Using low-temperature heat, gently burn and melt the coating material.

Micro Sandblaster Method

This technique involves projecting a fine abrasive powder onto the coating to flake off the material.

engineer observing PCB with equipment

 

Which Technique is Best for My Conformal Coating Material?

Urethane Coatings

  • Grinding and scraping method
  • Solvent method
  • Micro-blasting method

Acrylic Coatings

  • Thermal removal method
  • Chemical solvent method
  • Scraping and grinding method
  • Micro-blasting method

Epoxy Coatings

  • Thermal removal method
  • Grinding and scraping method
  • Micro-blasting method

Silicone Coatings

  • Grinding and scraping method
  • Micro-blasting method
  • Chemical solvent method
  • Thermal method

Parylene Coatings

Parylene coatings are often harder to remove, but you can typically use the micro-blasting, grinding, scraping, and thermal methods. However, at HZO, we have simplified the reworking process using technology. In the next blog in this series, we will discuss reworking Parylene in general and detail how we simplify the process.

For more information on thin-film coatings for your project, contact us today.

 
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Parylene Coating Removal - Methods & Explanation

June 17, 2021 / by Mallory McGuinness-Hickey posted in Parylene, Coating Process

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In the last blog post in our removing conformal coating series, we discussed removing conventional conformal coatings, such as polyurethane, acrylic, epoxy, and silicone, from components such as printed circuit boards. Parylene coatings, however, present unique challenges regarding rework and removal.

Parylene conformal coatings are unique in their ability to be polymerized and deposited by vapor deposition onto PCBs maintained at room temperature, unlike liquid conformal coating application methods that may lead to coating defects. The result is an extremely thin, pinhole-free, high-purity coating with proven performance for mission-critical applications and consumer electronics devices that must remain reliable.

Read about Parylene Type C and Parylene Type N

Parylene is often superior in barrier properties, uniform coverage, and performance in thinner layers compared to other conformal coatings, with less stress on mechanical structures and virtually no added bulk.

Learn more about what Parylene is used for.

Additionally, Parylene has been trusted for decades due to its remarkable chemical resistance properties to withstand corrosive gases and liquids and maintain performance in extreme temperatures and intense electrical activity.

 

Want to know if HZO Parylene meets your specifications?

 

However, the beneficial properties that make Parylene the “gold standard” of conformal coating can also make the material difficult to remove. Thankfully, there are methods you can use to remove and rework Parylene when necessary.

Learn more about Parylene’s benefits, such as Parylene’s optical properties, and biocompatibility  

 

Why is Parylene Removal Necessary?

From time to time, it is necessary to rework or remove the coating. Perhaps the job specifications changed, or a Parylene vendor incorrectly applied the coating.

One example of poor application is Parylene delamination, in which the conformal coating separates from the coated surface. This results in an unattached, torn, non-conformal coating and an unacceptable finish. Delamination defeats the purpose of Parylene conformal coatings and should be avoided at all costs. Even partial lifting can render the protective coating useless.

There are many sources of Parylene delamination, including standard processes such as demasking, which can create a need for exceptional quality control inspection procedures after production. Other causes include:

Coating porosity: A difference in vapor pressure between the component surface and the Parylene coating creates vulnerability to moisture permeation and intrusion into the substrate. As pressure fluctuations and temperature subsequently occur, osmotic pressures are generated, separating the coating from the component.

Incompatible materials: The component surface and the Parylene coating must bond together for successful coverage. When the Parylene and the surface are incompatible, incongruous surface energies are generated, causing minimal bonding.

Contaminated surfaces: Improperly cleaned component surfaces do not support adhesion.

Regardless of the reason, Parylene removal must be efficient and safe to protect the integrity of the coated substrate material or component.

The following methods are popular ways to approach Parylene removal.

 

Mechanical Parylene Removal

Parylene’s strong capacity to withstand manipulation, exceptional uniformity, and overall strength means that mechanical removal methods should be used with care, as there is potential damage to the final production. However, as Parylene is a soft polymer, mechanical techniques can be candidates for Parylene removal.

Methods such as picking, cutting, and scraping are effective but run the risk of damaging components, substrates, and delicate track lines. This type of removal requires considerable attention and care. It is possible to achieve good spot removal with appropriate masking, but mechanical techniques may prove undependable for larger-scale surfaces.

Removing Parylene with Micro Abrasion

Micro abrasion is a process performed with automated or handheld human systems that pinpoint a targeted removal area, propelling inert gas or dry air, and abrasive media at the Parylene coating. This removal method is suitable for both whole board and spot removal. It is generally easy to implement, quick, cost-effective, and environmentally friendly.

Thermal Removal

Although Parylene can withstand high temperatures, a high-temperature oven or soldering iron can effectively remove Parylene in specific, small areas. As heat is applied, the coated component rises from the board and lifts off.

Although Parylene can withstand high temperatures, a high-temperature oven or soldering iron can effectively remove Parylene in specific, small areas

This technique may be adequate for small repairs. It is less reliable for large surfaces, but for particular jobs, it can still be an effective means of removal. However, residues and discoloration may occur, and due to Parylene’s high melting point, heat-sensitive substrates may be at risk for damage. Thermal removal can be challenging to manage and is not recommended without the help of Parylene experts.

thermal removal parylene removal method

 

Parylene Removal with Tetrahydrofuran

Parylene is chemically inert, resisting chemical degradation. However, one chemical has been used to strip Parylene from substrates and components, a colorless organic compound called tetrahydrofuran (THF), with a chemical formula of (CH2)40. This solvent softens the Parylene coating, temporarily loosening the adhesion bond between the substrate and coating. At this point, the Parylene can be lifted off with tweezers. Although THF can be successfully used to remove Parylene, caution must be taken to avoid damaging the coated component, and the solvent should only be used for complete coating removal. For the security of components underneath the coating, it is worthwhile to consider other removal processes before using TFH.

Laser Ablation for Parylene Removal

Laser ablation is a process that removes material from a surface by irradiating it with a laser beam. The beam can cut, drill, or mark delicate materials, providing precise removal. At HZO, a laser ablation process converts Parylene to gas or plasma with pulsed laser sources. This method can be cost-effective for complex removal jobs, results in better quality removal results, and completely Parylene-free areas and 3D devices can be effectively serviced.

Conclusion

There are multiple effective methods to remove Parylene should the need arise. Each method has its strengths, so it’s necessary to know your options and what method will be best for your project.

If you are looking for Parylene removal services or to discuss your project with Parylene experts, please message us today. While removing Parylene can be challenging, if you partner with a company with the best skillsets and processes, the job can be simplified and more cost-efficient. We can also help with scalable Parylene equipment, cost-saving Parylene masking automation, and address other concerns about the cost of Parylene services.

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Definitive Guide to Conformal Coating Application Methods

June 2, 2021 / by Mallory McGuinness-Hickey posted in Conformal Coatings, Coating Process

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Conformal coating materials, including acrylics, epoxies, urethanes, silicones, and Parylene, introduce different benefits, drawbacks, and challenges to any project. Because there is no one-size-fits-all solution to unique electronic protection requirements, you must carefully consider these variables and how they may apply to your needs.

Learn how to choose the best conformal coating for your application 

Consideration must also be taken for the conformal coating application method, which includes brushing, spraying, dipping, and chemical vapor deposition. Your choice of application will hinge upon the complexity of the substrate to be coated, required performance, and throughput requirements. Curing time, capital investment, and possible rework and removal due to conformal coating defects may also factor into the overall selection of your conformal coating application method.

This blog post will briefly discuss popular conformal coating techniques and discuss each method’s benefits, drawbacks, and potential challenges.

Understand conformal coating vs potting

 

Brushing

brush for conformal coating application

Brush coating is a well-known application technique used to coat a limited quantity of substrates. In this process, the operator formulates coating material, dips a brush into the coating container, and manually applies it to the substrate. With proper application, this method can yield excellent results on even surfaces.

Brush coating is the cheapest and easiest conformal application method, requiring minimal maintenance, repairs, or upgrades. Equipment costs are low, and due to the controlled nature of the process, there is often a reduced need for masking. Although the process is simple, with little capital outlay, the quality and results vary as they are operator-dependent. The process is labor-intensive, and the operator needs proper protection from the coating environment. Obtaining a uniform build over an entire assembly is complicated, and contamination issues are a concern.

Manual brushing is a viable choice for low volumes, such as prototype runs. Brush coating can also be suitable for touchup after repairs or rework. This conformal coating application method also works well for high-topography PCBAs due to the operator’s measure of control.

 

Advantage Disadvantage
Straightforward and low startup costs Difficult to control the material thickness
Suitable for low-volume, high-mix production Easy to create voids and bubbles
Suitable for rework or touchup application The brush can be the cause of residual FOD (bristles)
Can protect against airborne FOD Operator experience dependent
Very good for small parts or where masking needs are challenging Part to part variability

 

Read the definitive guide to conformal coating types.

 

Spraying

spray coating equipment

Spraying, either manual or automated, is another popular method of application. This technique is faster than brush coating, and when the solvent dilution, pattern, and nozzle pressure are appropriately combined, consistent, reliable results are possible. This method requires masking to shield sections or components of a PCBA before an operator uses a handheld spray gun or automated equipment to apply a thin conformal coating film to the boards.

It may be necessary for complex boards and components for an operator to spray coating on several planes to ensure complete coverage underneath. The feed system type, the material’s temperature, line speed, and atomization pressure affect coating thickness, and viscosity control is critical. If the coating is too thick, the PCBA gets cob webbing. If too thin, wicking and running can occur. Typically, thinning the coating with solvent is necessary for spray application. 

Although spraying costs are low to moderate, more masking time is required than brushing, possibly offsetting the savings. Although spraying may be less expensive than other methods, the temperature and humidity of the coating environment must be conditioned and factored into the startup costs. Additionally, operators should have adequate respiratory equipment.

 

Advantage Disadvantage
System not complicated Need to contain excess over-spray or any harmful vapors
Reasonable implementation cost Material wastage/loss in the process
Aerosol is suitable for rework Usually much higher in VOCs as dilution is needed for spray
Angled spray may provide a better coating on high-topography assemblies Thin material may require multiple coat/cure cycles to get desired thickness

 

Dip Coating

dip coating equipment

Dip coating, which can be manual or automated, is one of the oldest coating application methods, effective at applying conformal coatings to assemblies that are not too irregular or bulky in shape. With this technique, units are masked, immersed into a tank of coating material, and subsequently withdrawn. Excess material is allowed to drip off, followed by demasking and curing. Coating thickness is contingent upon immersion and withdrawal speeds. 

Dip coating completely encapsulates the PCBA or component and is a low-cost, efficient process for high-volume applications. Correctly done, dipping yields uniform coverage and repeatable, predictable film thickness. Additionally, both sides of the board coat simultaneously, improving efficiency. That said, the open atmosphere around the dip tank can cause contamination. Consequently, the coating material in the tank must be periodically purged and replaced, potentially increasing costs for high-volume production. Variability of viscosity variations and inconsistent coating thickness can make the dipping process a crude one with little control. 

Dip coating is a popular choice for high-volume production, as carriers may allow for the coating of as many as 40 PCBAs each cycle, equating to around 500 units per hour.

Advantage Disadvantage
System not complicated/easy design Open to environmental impacts – temperature/humidity
Relatively not expensive Material viscosity must be monitored
Reused material/process savings Coating reservoir can become contaminated

 

Chemical Vapor Deposition (CVD)

Chemical vapor deposition is used exclusively with Parylene coatings. The CVD process is performed under vacuum, with specialized equipment that includes a coating chamber.

Parylene dimer is placed in the vaporizer chamber, and the system is placed under vacuum. The vaporizer is heated to around 150 to 170 °C until the dimer sublimes from a solid to a gas.

The dimer gas travels through the pyrolyzer, heated at a much higher temperature, from 550 to 700 °C, where the dimer is “cracked” into two activated monomers. From there, the monomer travels into the room-temperature deposition chamber and coats everything in the chamber with monomers that connect to other monomers, forming a polymer film.

An overview of the chemical structure changes for this process for Parylene N is illustrated below.

 

Parylene deposition process for Parylene NFigure 1 Typical deposition process, as illustrated with Parylene N

 

Since it deposits as a vapor that lands on and begins building up a thin film that wraps around components and substrates with little to no change in thickness or coating defects, Parylene is a truly conformal coating that ensures protection from corrosive environments, even at tight corners.

All surfaces can be coated evenly regardless of chamber position, and the coating deposits the same thickness all around the objects being coated. This vapor phase coating process also leads to pinhole-free coatings, absent of defects. Masking and demasking are typically required, but no curing process is necessary.

However, CVD material and equipment can cost more than other methods, and particular expertise and tools are required for rework. CVD is a batch process, and most CVD equipment yields limited volume.

Advantage Disadvantage
Uniform coverage on all surfaces Batch-mode
Excellent material properties Material/equipment can be expensive
No harmful vapors during the process Requires specific processes for rework

 

CVD Process with HZO

After reviewing the options above and deciding that chemical vapor deposition with Parylene is an ideal application process for your project, consider HZO. Proprietary CVD equipment with the largest coating chambers in the industry and optimized square chambers addresses many of the limitations of the CVD process. Our dedicated engineers look forward to helping guide you through the coating process from beginning to end, so send a message today.

Watch a webinar on how to incorporate CVD into your manufacturing process.

 

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How to Choose a Nanocoating Material

April 28, 2021 / by Mallory McGuinness-Hickey posted in Coating Properties, PECVD Coatings

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As engineers, it is our job to bring products to life and ensure they operate as expected until the end of the product life cycle. Therefore, a large part of our job is to prevent premature failure by providing electronic products with appropriate protection from environmental threats that can cause an immediate or unplanned shutdown. To do this, we must evaluate protective solutions and sometimes think outside the box. We may need to rethink protection in a landscape punctuated by miniaturization, ruggedization, and sustainability concerns. Nanocoating technology can often address these needs better than current methods like gasketing, protecting products from liquid damage and its subsequent harm to business reputation.

 

Hydrophobic Nanocoatings to Improve Performance

Protective nanocoatings are thin films of coating material measured in thicknesses of nanometers applied directly to the surface of PCBAs and other components or materials. With nanocoatings, product design teams can meet many objectives, including material hydrophobicity (water-repellent) due to the low surface energy of the coating. This may be important for a wide range of applications, like increasing the water resistance of electronics, helping your down sleeping bag stay dry, or allowing water to bead off car windshields more easily. Nanocoatings' other protective capabilities include corrosion protection, hardness, or, sometimes, oleophobic properties (oil repellent).

To effectively apply hydrophobic coatings of this caliber, vacuum deposition is required to ensure the quality and consistency of the application. Plasma-enhanced chemical vapor deposition (PECVD) is a popular nanocoating process because it is flexible, controllable, and appropriate for various applications. PECVD utilizes plasma, a high-energy, gaseous state that enables material to deposit onto substrates. The process parameters vary tremendously, including power, plasma type, temperature, deposition time, pressure, gas flows, and gas composition. Adjustments to these parameters make it possible to produce highly-performing thin films tailored to your protection requirements. Due to the versatility of the PECVD process, a wide range of materials can be deposited to help engineer a specific coating solution.

The material you ultimately use for deposition is closely related to coating performance, so it is essential to select carefully. The criticality of material choice begs the question: how do you choose the best nanocoating material for your project?

 

Download our HZO Nanocoating Datasheet

 

 

Choosing the Right Nanocoating Material

 

There are halogenated materials (fluorocarbons and chlorocarbons) and halogen-free (silicones, hydrocarbons, metal oxides, and metal nitrides). Ultimately, performance requirements and sustainability concerns will determine which is preferable.

Halogenated Materials
Halogenated material processes produce coatings with high hydrophobicity or strong etching capabilities. Halogen-free material processes, such as silicones and metal oxides, deposit coatings that serve as strong water barriers, offering strong performance.

Halogen-Free Materials
Sometimes non-halogenated materials are preferable for environmental reasons. If you are considering halogen-free materials, the choice does not end there. You’ll have to consider other requirements. For example, metal oxides may provide more substantial protection, but a hydrocarbon coating may provide acceptable performance and is generally easier to handle than other materials.

 

Understanding the Performance Requirements

 

While understanding if you prefer halogenated or halogen-free materials will be a critical part of your decision, you must thoroughly understand your product’s performance requirements to choose which material to use. Hydrophobic, hydrophilic, and corrosion resistance properties will determine whether a fluorocarbon, silicone, metal oxide or another material is preferred.

 
hydrophobic nanocoating

 

After You Have Chosen a Nanocoating Material

After determining what material type to use, the selected material will determine the precursor (materials that chemically react and/or decompose on the substrate’s surface) and plasma parameters to use. Different gas or liquid precursors result in different coatings. For example, methane may be used as a simple hydrocarbon coating, carbon tetrafluoride for a fluorocarbon, or hexamethyl dioxolane for silicone.

Even after determining the precursor, the flow rates of that liquid or gas and other parameters can dramatically affect the final coating properties. For example, adding oxygen, nitrogen, or argon can completely change the results. Argon is inert in the overall reaction, but it may change the reaction mechanism, which is the sequence of steps that make up the overall reaction. The mechanism affects what film is deposited. Adding oxygen may create oxides, and nitrogen may form nitrides, which add to the film’s hydrophilic properties. Meanwhile, different flows of the same gases may result in different coating properties. Gas flows may range from a few sccm (standard cubic centimeters per minute) to 10,000 sccm or more. This flow rate difference may change the reaction mechanism, altering what is deposited.

 

Seeking Technical Expertise

As you can see, with PECVD, there are many options where significant experience and development will be required to understand which materials are best. If you are interested in PECVD coating technology and want help getting started, please reach out today for a consultation. 

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NEMA vs IP Ratings Explained

April 14, 2021 / by Mallory McGuinness-Hickey posted in Protection Capabilities, Coating Properties

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Once upon a time, computers only sat perched on desktops, but that is no longer the case. Deployed in harsh industrial, medical, automotive, and consumer household environments, electronics must now withstand exposure to water and liquids ranging from “condensing” moisture to total submersion that requires waterproof design. They must reliably operate despite threats posed by humidity, corrosives, and other outdoor contaminants.
 
 

To assure your customers that your electronic products can dependably withstand these challenges, you must meet reliability standards, such as Ingress Protection (IP) Standards or National Electrical Manufacturers Association (NEMA) Protection Ratings. These systems classify an enclosure’s protection level from harmful elements by defining protection posed by solids and liquid ingress. It is crucial to select the correct standard to assure your clientele that the product you offer will be reliable in specific environments. This choice can be complicated because comparing NEMA vs IP rating systems is impossible, but alternative solutions may eliminate the need to select one or the other.

 

View our webinar to see if it’s time to rethink enclosures.
 
 

IP vs. NEMA-Rated Enclosures

Any comparison of Ingress Protection ratings and NEMA standards will only be approximate. An IP Rating only considers enclosure protection against water ingress and solid foreign objects. Meanwhile, the NEMA rating system, often used as an industrial enclosure rating system, considers these factors, as well as other hazards such as corrosion. So, while you can say a NEMA type is equivalent to an IP rating, it is impossible to say that an IP rating equals a NEMA rating. Additionally, the two systems use different test parameters to define the level of protection, so there is no easy conversion.

 

NEMA Ratings

NEMA electrical enclosure ratings have numeric values, sometimes followed by a letter. Each rating corresponds to the hazards an enclosure must protect its interior and may indicate indoor or outdoor use.

You can explore a quick guide to specific NEMA ratings here.

When choosing a NEMA enclosure type, it’s essential to consider both the environmental hazards the interior needs protection from and the enclosure location to use NEMA ratings appropriately. For example, a NEMA 4 rating is popular because it accommodates outdoor environments and multiple weather types. NEMA rating 4X features watertight seals, corrosion resistance, and protection from dust for more extensive protection.

 

IP Ratings

IP ratings may be designated by two or three numbers corresponding to protection from solids, liquids, and impacts. X replaces the number if a device does not have a specific rating. The first number signifies the object size that the enclosure prevents from entering. The higher the value, the more protection from solid ingress, such as windblown dust.

The next value indicates liquid ingress protection, with digits ranging from zero to eight, with increasing amounts of protection as the numbers increase. Finally, the third value corresponds to the mechanical impact an enclosure can withstand. This value may not be present in some electronic products because most codes do not require its presence.

A short guide to IP specifications can be found here.

 

Read our IP Checklist

 

Rethinking Enclosure Standards

IP or NEMA standards may not be the best indicator for the degree of protection you need. For example, while IP liquid ingress testing works in the lab, it may not perform the same in real life. Chances are that you will still need to demonstrate that your product can meet these standards to meet customer specifications.

Thin-film coatings can be an easy and efficient way to meet both NEMA and IP liquid ingress standards. These polymeric barriers protect from the inside by directly applying components and PCBAs. They are lightweight and thin, helping you eliminate seals and, therefore, excess bulk and weight. The protective coatings also blend into the product so you can offer aesthetically pleasing, ergonomic, and functional products easily. Thin-film coatings can be used in a two-phase approach to protection that is failsafe and can help you save money and time customizing enclosures.

 

HZO Coatings and Relevant Standard Equivalents

NEMA vs IP table comparing HZO coatings to the standard

 

Contact Us

 

HZO offers thin-film coatings to protect your electronic products. We focus on tailored solutions to your protection requirements and can help you exceed liquid standards easily with proven solutions, with no enclosure testing required. Download our datasheets, or send us a message for a consultation.

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Overview of the Plasma Nanocoating Process

March 26, 2021 / by Mallory McGuinness-Hickey posted in Coating Process, PECVD Coatings

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Nanocoatings, thin films measured at the nanolevel, serve numerous purposes. But for many product design engineers, the ability to safeguard electronics with protection capabilities such as hydrophobicity, corrosion-resistance, and dielectric and thermal properties, is top of the list. Protective nanocoatings empower organizations to mitigate risk associated with downtime, reduce repairs and warranty claims, and cultivate market confidence with remarkably reliable electronic products.

Download our white paper on thin-film coating depositions, including PECVD and a summary of PECVD vs CVD

 

 

Plasma Surface Technology Benefits

Plasma application processes can produce nanocoatings with many beneficial substrate surface characteristics, including:

  • Hydrophobicity
  • Oleophobicity
  • Humidity/temperature protection
  • Excellent flammability protection
  • Low dielectric constant with good high-frequency properties
  • Good dielectric strength and high bulk and surface resistance
  • Splash protection
  • High barrier protection against corrosive chemicals and gases while providing low permeability to moisture

These valuable benefits have piqued interest in plasma-based nanocoatings and the processes used for their deposition.

Read "How Small is a Nanometer?"

Plasma Coating Processes

While several methodologies exist to apply nanocoatings to substrates, including plasma spray deposition, plasma-enhanced chemical vapor deposition (PECVD) is popular due to enhanced process control and beneficial physical film properties.

 

a chart explaining the nanocoating process

PECVD Process

 

The PECVD Plasma Application Process

PECVD harnesses plasma energy to deposit nanocoatings through several power sources, including microwave discharge, radiofrequency, and direct current. Using PECVD equipment, gases are energized to form a plasma and a mixture of ions, radicals, excited atoms, free electrons, and molecules to deposit the nanocoatings.

Possible materials to form the coatings include metals, polymers (silicones, hydrocarbons, fluorocarbons), oxides, and nitrides, representing many possibilities. The resulting films are highly cross-linked, dense, pinhole-free, and uniform; these attributes lend to good physical properties.
The process offers precision control over these film properties, yielding various chemical, thermal, mechanical, electrical, and optical benefits.

 

HZO PRO800-PL Proprietary Nanocoating Coating Equipment

HZO PRO800-PL Nanocoating Equipment

 

PECVD Parameters to Consider for Optimal Performance

Internal and external plasma parameters may be modified to affect the resulting film. Internal plasma parameters include the precursors used, the distribution of various species in the plasma and the species’ energy, and the homogeneity of discharge. External parameters include temperature, applied power, total pressure, gas flow rates, pumping speed, and reactor geometry.

PECVD Benefits

The deposition process allows for a wide range of material usage, including unconventional precursors that can deposit on surfaces with complex geometries, typically at lower temperatures than other vacuum deposition processes, such as thermal chemical vapor deposition. It is possible to tightly and efficiently control these precursors while generating few by-products, allowing for precise film composition and uniformity control. As a result, PECVD nanocoating chemistry is unique and often unobtainable with standard liquid coating deposition methods.

 

PECVD Applications

PECVD coatings are used in applications that require lower cost and high efficiency, including optical coatings, corrosion resistance, and dielectric films.

Applications include:

  • Mobile phones
  • Earbuds
  • Smart speakers
  • Wearables
  • Outdoor cameras
  • Hearing aids
  • Catheters
  • Smart patch
  • Connected health devices
  • Automotive in-cabin sensors and electronics
  • Automotive cabin filters
  • Automotive cameras
  • Doorbell cameras
  • POS scanners
  • Air quality sensors
  • Smart home applications
  • LEDs
  • Drones
  • HVAC sensors
  • Industrial equipment controller

PECVD Coatings with HZO

At HZO, our in-house designed deposition equipment is optimized for faster deposition rates with scalable reactors for High-Volume Manufacturing (HVM). The fixtures used during the deposition process (directional plasma only) provide an alternative to masking, a process used to ensure coating does not cover parts such as connectors. This alternative can save time and money, as masking and demasking can be labor-intensive.

  • Plasma-based technology leverages a variety of chemistries that can quickly be adapted to specific requirements.
  • Coatings can be single or multi-layer, with one or more chemistries applied. This hybrid approach allows the delivery of target properties.
  • Materials include halogen-free alternatives.
  • Typical thickness varies from 300 nm to 3 µm.
  • Masking requirements can generally be addressed in the chamber as part of the deposition process using a shadow mask to isolate areas to be kept free of coating.
  • Minimal footprint required to perform coating operation.
  • Features include liquid protection, anti-corrosion, etc.
  • Solutions are scalable for high-volume manufacturing at competitive pricing.

Download the HZO Sentinel Series™ Datasheet

 

For more information on our plasma-based nanocoatings, please contact the HZO team with any questions or concerns. Our engineers would love to give you a free consultation to determine if the plasma nanocoating process is ideal for your application.

 
 
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How To: A Wearable Device Design That Consumers Actually Want

March 20, 2021 / by Mallory McGuinness-Hickey posted in Thin Film Applications, Value of Coatings, Resources

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Wearable devices provide insight and convenience to consumers through activity tracking and biometric data that they can easily access through a wearable app. But many wearable product designers have focused too much on producing functional devices without emphasizing the humans that wear them enough. This tendency could be to the detriment of user experience, limit user interaction, and make consumers less likely to purchase from your company again. Here are three quick tips on designing a wearable device that addresses human issues: discomfort and inconvenience, display issues, and lack of ruggedization for real-world usage.

 

1. Learn How to Make Wearable Technology Truly Wearable

 

 

Wearable tech can be challenging for design engineers because the body moves constantly, and humans want to move without constriction. Therefore, designing small, light, and comfortable wearables should be a priority.

For this reason, it is a good idea to begin the design process with a human factors and ergonomics analysis. This scientific discipline seeks to understand and optimize interactions among humans and systems to improve both system performance and the well-being of humans.

Consumers are likelier to wear devices with thinner, smaller, rounded form factors that lay flush on the body, applying minimal pressure. To ensure your product will be comfortable, test usability factors with real users and determine how easy and comfortable it is to move while wearing your product. Don’t forget to consider people’s different body sizes and types. For example, our customer Nike offered their FuelBand in several wristband sizes that the consumer would choose during the purchase process.

Finally, remember to design for every aspect of the use cycle, such as cleaning, bathing, showering, and leisure activities. Make an effort to be conscious of when and how humans clean their wearable devices so you can create a usable, convenient, easy-to-clean device consumers will want to use. Remember that users will not want to remove their devices during routine activities such as bathing and showering (and may not take off their wearables before swimming or entering a sauna), and accommodate this in your product design. The more convenient it is to use your product, the more consumers want it.

 

Watch our video series about designing reliable consumer electronics devices.

 

2. Consider the Display On-Device and What it Means for User Experience

 

 

To determine the right display for your wearable, ask yourself about the level of interaction required with the wearable. Wearables without display afford more design flexibility, are cheaper, and are simpler to produce. However, no available visual communication with the wearable will limit the level and scope of human interaction with it.


Minimal output displays portray selected information critical to the wearable experience. This type of display is one-directional, so the user can view it but cannot enter any input, limiting interaction. Another option is a full display, which allows for strong device interaction and a wider feature set. Determining which type of display is most appropriate for your users is an important decision that, unfortunately, may entail an aesthetics-functionality trade-off.

No matter which display you choose, you should expect and design wearables that will endure connectivity problems. Try to integrate some core functionality in your product’s offline mode when planning for your wearable UI. At a minimum, ensure the product explains what is happening to the user by incorporating wearable alerts when there is no internet connection to avoid confusion. If you choose a wearable with no display, this could be indicated through the mobile app.

 

3. Learn How to Design a Wearable Device for the Real World

 

 

Designing devices worn on the body can be complicated because they must reliably work in variable operating environments. In other words, they must go where humans go. Humidity, submersion, harsh weather, and corrosive exposure threaten wearable PCBAs. Don’t make the mistake of simply ensuring a device can pass reliability tests in the lab but not designed for the real world. Typically, consumers use Ingress Protection (IP) standards to guide their purchasing decisions, so achieving a certain level of water resistance is necessary.

Download our IP checklist.

 

Conventionally, product designers have used seals to do this, but this method may not focus as much on user experience as it should. Humans frequently move, exposing these devices to vibration, which can dislodge seals and leave wearables unprotected from corrosion.

Another option is conformal coatings for wearable moisture resistance and corrosion protection. These polymeric films are applied directly to the circuitry as a barrier against many environmental threats. However, wearables have minimized form factors and require these coatings to apply thick layers, which may be too bulky and heavy, causing discomfort and inconvenience.

These legacy methods are often appropriate and do have their place. However, if you are placing more emphasis on users to improve your product experience, it might be worth considering Parylene conformal coatings. HZO’s Parylene can provide protection that meets or exceeds the corrosion protection of other conformal coatings at 50% thickness.

 

Visit our Consumer Electronics market page

 

The chart below describes Parylene thickness and the corresponding standards and IP protection levels they meet:

 

Table 1: Parylene Thickness, Relevant Standards, and IP Protection Levels
Thickness(μm) Relevant Standards IP Protection Level
0.1 to 5 UT Type in IPC-CC-830C IPX3/IPX4
5 to 12.5 UT Type in IPC-CC-830C IPX4/IPX7
12.5 to 25 IPC-CC-830B IPX7/IPX8

 

Parylene Conformal Coatings for Wearables From HZO

 

As a proven method trusted for decades in mission-critical applications, Parylene eases many design headaches and addresses the user-focused issues above. As it provides robust protection at a fraction of the mass of legacy methods, you can make ruggedized wearables that are also truly wearable. Parylene’s superior chemical resistance properties allow your users to clean their products throughout the entire product life cycle safely. Additionally, using Parylene instead of seals can make it easy to design and produce wearables that meet finish, style, longevity, and reliability expectations, leading to consumer purchases.

It is possible to minimize offline disruptions because, unlike the other thick conformal coatings and seals, Parylene is applied in thin layers, facilitating RF signal transmittance.

When you work with HZO, our engineers will create a coating solution around your needs that easily fits into your production. From DFM services to QA, our team of experts will walk you through every step of the protection process, eliminating headaches and simplifying your process. If you want to discuss your project with our team, contact us today.

 
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What is Corrosion & Does It Ruin Electronics? How to Remove It?

October 15, 2020 / by Mallory McGuinness-Hickey posted in Protection Capabilities

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Imagine the following scenario: You are washing the dishes, listening to music on your smartphone when suddenly the unthinkable happens – the phone that was nestled safely in your shirt pocket tumbles out and into a sink full of soapy water and dirty dishes. You manage to frantically retrieve your precious phone from its watery grave, dry it off, and find that somehow it is still working! It’s a miracle! You acted fast to save your phone, and you didn’t even need a bag of rice! All is well in the world of potentially water-damaged electronics… until two days later, when, for no apparent reason, your phone now doesn’t work, it short-circuited. Your miracle has turned into a nightmare. Water damage: 1. You: 0.

 

a phone dropped in water and being ruined by corrosion
 
The Meaning of Corrosion and What Causes It

We’ve discussed the science behind circuit board corrosion and how to prevent water damage with different conformal coatings, discussing why electronics and water don’t mix. One of the reasons we mentioned is the hidden and most puzzling cause of water damage: corrosion. Corrosion is the gradual breakdown of material, usually metal, by a chemical reaction with its environment. The most common form of corrosion occurs when you combine metal with water and oxygen, creating iron oxide (more commonly known as rust). This reaction occurs when you combine these elements for an extended period.

Does Corrosion Ruin Electronics?

There is no specific time frame in which deterioration happens; an electronic device can begin corroding a few hours after the initial water damage incident, or it can last days unaffected before showing any signs of a problem. How fast it sets in depends on humidity levels, the severity of the water damage, how long the device was submerged, and even how it is made. If the device was made to prevent water damage, exposing it to water won’t affect it. These factors significantly affect the time frame under consideration for a water-damaged device.

Learn More About Corrosion Protection

 

How to Remove Corrosion from Electronics 

You must be very careful when cleaning up corroded electronics after water damage. You can damage the device further if you don’t know what you are doing, and you could also potentially injure yourself. Remember: devices and liquid generally don’t mix, so any time you apply cleaning solutions to a device, you must be cautious. The average consumer should never attempt to repair a device without professional assistance. The best rule to remember is to take it to a professional when in doubt! With that being said, here are a few helpful tips to keep in mind when dealing with deterioration and devices with water damage:

 
  • To clean a device post-water damage, always remove any batteries,  power connectors, or power supplies first. This not only prevents harm to you but also prevents any short-circuiting to the device. Doing this will expose extra connectors that may already have corroded, so exercise caution.
  • Look for any white or green “crusty” areas on the device, especially on the battery connectors, charging ports, circuit boards, logic boards, SIM card connectors, or any other major metal connectors on the device.
  • Use cotton swabs and a cleaning solution such as isopropyl alcohol, baking soda, water, or even vinegar to clean it. Gently apply the solution to the affected area and wipe back and forth until the corrosion is removed. Leave some solution on the corroded area and wipe it off later.
  • Dry your electronic device with a soft cloth or a hair dryer in a cool setting – do not use heat to dry out your device. Ensure your device is dried extremely well before attempting to replace the battery and turn the device on. Any water left in the device could cause additional water damage.

 

Remember that whenever you are dealing with a water-damaged device, there is no guaranteed way to fix it once it has been subjected to water or already has deterioration issues. You can take steps to improve your chances of repairing it, but in the end, you have to cross your fingers and hope for the best.

 

circuit board contamination

 

If you want to learn more about waterproof electronic devices and the technology that goes into them, then visit our website! We provide protective coatings to eliminate corrosion from happening in the first place. Contact us today to waterproof your new electronic device, or dig deeper to learn how we protect electronics from corrosion.

 
 
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Conformal Coating Thermal Conductivity - Prevent Overheating

October 2, 2020 / by Mallory McGuinness-Hickey posted in Protection Capabilities, Coating Properties

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Design engineers have more to worry about these days than ever before. The demand for smaller electronic devices with more capabilities is exponentially growing, causing engineering challenges also to grow. More integrated circuits, resistors, diodes, transistors, and capacitors must be packed into a shrinking space, increasing a device’s susceptibility to overheating due to a reduction in thermal flow.

Done improperly, poor design and engineering can directly cause overheating, leading to decreased reliability, premature failure, and damages resulting in avoidable cost and brand damage. All electronic devices and circuitry generate excess heat as current flows through a circuit, causing the need for better thermal management. Each component has a rated maximum operating temperature, and heat dissipation is critical to avoid overheating and exceeding the temperature limit.

 

How is Heat Removed from Electronics?

Heat must be dissipated to ensure that devices remain safe, reliable, and perform as intended. This process can happen through many different methods, including:

  1. Convection: a transference of heat through moving fluids
  2. Conduction: a process in which heat dissipates throughout a material
  3. Radiation: allowing heat to dissipate through electromagnetic waves

 

Mechanism Definition heat dissipation path percentage of heat

Conduction

Heat transfer between objects that are in physical contact. External pins of component to the printed wiring board. Then, convection into the atmosphere. ~80%
Convection Heat transfer between an object and its environment due to fluid motion (liquid or gas). Top surface and sides of the package into the atmosphere. ~10%
Radiation Heat transfer through the emission of electromagnetic waves. Radiative heat from the package surface area. Low contribution to total heat dissipation unless package surface area is relatively large. ~10%

 

*Estimates For A 352-pin BGA Type Component

 

Conformal Coating Thermal Conductivity

In many electronic designs, ~80% of heat energy is dissipated through conduction to some form of a heat sink designed to dissipate heat by spreading it over a larger surface area, removing the heat to the atmosphere through convection.

The heat flow between a component and ambient air is modeled as a series of resistances to heat flow. The sum of these is the total thermal resistance (°C/W). The goal here is high surface area in contact with air and a material with high thermal conductivity.

That being said, common heat sink materials are materials with high thermal conductivities:

Material thermal conductivity (W/mk)
Aluminum Alloy 1050 229
Aluminum Alloy 6061 166
Aluminum Alloy 6063 201
Copper 400

 

 

 
 

Conformal Coatings and Heat Dissipation: Considerable Challenges

 

Overheating is not the only reliability challenge for design engineers. Environmental constituents such as corrosives threaten reliable printed circuit board (PCB) performance. Engineers increasingly incorporate conformal coatings into their designs as devices shrink instead of enclosures and seals, which can consume precious real estate in miniaturized devices.

These polymeric films are used as a barrier layer to contaminants, corrosives, solvents, and solid materials commonly found in operating environments. Materials such as acrylics, silicones, epoxies, polyurethanes, and Parylene can be applied to substrates, enhancing electronic reliability in the harsh environments that next-generation electronics face today.

These protective coatings can outperform seals and enclosures when it comes to reliability. The electrically insulative properties of conformal coatings, such as dielectric strength, prove useful here; spacing between conductors can also be reduced, allowing for the integration of more electronic components.

Learn more about the dielectric constant of insulator materials in our blog.

Unfortunately, traditional conformal coatings have low thermal conductivity, generally between 0.125 and 0.335 in W/mK. As the chart above indicates, these values are hundreds to thousands of times lower than those for ceramics or metals. As such, conformal coatings are good heat barriers, and when used in thick layers, they can interfere with the heat transfer path, impeding heat dissipation.

Although formulating a coating with metal or inorganic fillers can increase thermal conductivity, the compositions containing metal fillers will also become electrically conductive, meaning they are no longer suitable for electronic applications requiring electrical isolation.

This presents a paradox to design engineers. There is a need for highly thermally conductive polymers capable of transferring heat that are also electrically insulative, particularly for high-density microelectronics.

For conformal coatings, if thermal conductance is a requirement, design engineers can take either or both of two approaches:

  • Employing a coating filled with as much thermally conductive filler as possible.
  • Integrating the thinnest coating possible, as thermal conduction is inversely proportional to thickness.

Although using a filler can lead to a gain in thermal conductivity, ironically, the benefit is offset by a thicker coating that is challenging to apply. The coating’s electrically insulating properties may be affected as well. 

 

Read more about waterproof design.

 

Parylene Conformal Coatings for Heat Dissipation

 

Regarding reliability, you shouldn’t have to choose between bulkier, less reliable barrier protection and susceptibility to overheating. Evaluating conformal coatings for heat dissipation entails several considerations: thermal conductivity, emissivity (the surface of a material’s effectiveness in emitting energy as thermal radiation), film uniformity, adhesion to the substrate, and film thickness.

However, thermal conductivity and film thickness are the most critical parameters for heat dissipation when selecting a conformal coating. This is where Parylene is a distinctive choice.

 

Coating thermal conductivity (W/mk) film thickness (um)
Desired High Low
Parylene N 0.13 2-50
Parylene C 0.08 2-40
Acrylic 0.13-0.25 30-130
Epoxy 0.17-0.21 30-130
Silicone 0.15-0.31 50-210
Urethane 0.21 30-130

 

Other conformal coating materials are typically applied at a thickness range of 50 to 250 microns. Parylene can be applied at a fraction of the thickness, ranging as low as 2 microns. For context, this is less than the width of a strand of human hair.  

 

Parylene Performance at Scale

 

At HZO, we provide Parylene services to industries where device overheating is a serious concern. But when it comes to conformal coatings, Parylene is not just a superior choice for heat dissipation. It exhibits many excellent properties that bolster device reliability, such as chemical resistance and the ability to remain reliable throughout a wide temperature range.

More information on parylene coating costs

Each Parylene type has distinct characteristics, so there is a Parylene for virtually every application. For example, Parylene C provides the best corrosion resistance of all the conformal coating polymers. My colleague, Dr. Sean Clancy, delivered an excellent webinar on Parylene’s corrosion resistance, which I encourage you to view. You can also download HZO’s Parylene datasheet to learn more about Parylene’s beneficial properties.

Something my team is incredibly proud of is our customer service. We have formed meaningful partnerships over the years, providing masking and demasking recommendations, offering DFX guidance, and working with our customers to integrate our coating process into many points of their production.

If you are interested in protection for your project and need to understand the alternatives better or are simply curious to learn how leading OEMs are designing the next generation of mobile, wearable, edge, and general electronic devices, reach out to us today or fill out contact or quote form to get started. We are not simply a job shop but a team of dedicated engineers who understand your design challenges. 

You do not have to settle regarding heat dissipation or electronic protection. Your device is in good hands when you work with HZO.

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IoT - Coating Consistency is Key

September 25, 2020 / by Mallory McGuinness-Hickey posted in Parylene, Coating Process, Coating Properties, Value of Coatings

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IoT sensors aggregate and send data to IoT dashboards, simplifying critical, complex decisions quickly. One key area where this is particularly true is the utilization of sensor data for predictive maintenance, a process that reduces downtime and lowers the total cost of ownership. Myriad other applications incorporate these “smart” sensors too.

Today, IoT sensors are ubiquitous, touching almost every aspect of life. Gas pressure sensors monitor pressure changes in oil, energy, and utility applications. Photoelectric devices (photo sensors) are now common in the consumer electronics vertical. Sensors are responsible for temperature monitoring, a typical use case for warehouse and inventory management, and HVAC systems monitoring.

Accelerometers detect subnormal industrial machine applications, while ultrasonic flow meters are coupled with IoT modules to send data about smart metering to a remote location. Moisture sensors have been critical in recent advances in smart farming, allowing for constant soil health monitoring. In the automotive sector, tunneling magnetoresistive sensors (TMR) are an increasingly popular way to measure mechanical displacement. And Particulate Matter sensors detect pollution in the industrial landscape and smart cities.

 

The chemical vapor deposition (CVD) process used to deposit Parylene conformal coatings can efficiently accommodate these complex surfaces. Parylene’s usefulness is primarily founded upon its ability to cover PCBA configurations with exposed internal surfaces, sharp edges, flat surfaces, points, and crevices with consistent coverage free of voids.

 

HZO PRO750 Parylene Coating Equipment

HZO PRO750 Parylene Coating Equipment

 

The Parylene Deposition Process – Consistent Coverage

Rather than dipping, spraying, or brushing pre-formulated layers onto PCBAs and other components, Parylene’s application method synthesizes the protective film in-process. This deposition system comprises a series of vacuum chambers that produce Parylene vapor, pyrolyze the vapor, then deposit the vapor as a polymer sequentially.

During the CVD process, gaseous Parylene penetrates the layers of a PCBA. Its vaporous consistency surrounds all areas as it builds coating protection along the exterior. The coating layers are substantially thinner than those provided by liquid conformal coating materials, enhancing reliability and functional versatility.

It has repeatedly been demonstrated that CVD is valuable for thin-film deposition on irregular PCBAs. CVD's Conformal layers are exceptionally uniform, even in the nanometer range. Because these coating layers are exceptionally thin, non-uniformity is minimal.

 

Reach out to an Expert 

Choosing Parylene conformal coating services isn’t a failsafe decision, like anything else. Problems can occur with the process and the material. This is particularly true if the wrong Parylene type is used for a coating project while another type could provide better coverage. If you need a consultation to determine if Parylene is the right choice for your project, contact the HZO engineering team today, fill out a quote form, or leave a brief message.

 
 
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Polyurethane Conformal Coatings - Benefits & Applications

June 23, 2020 / by Mallory McGuinness-Hickey posted in Conformal Coatings, Coating Properties

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Conformal coatings are polymeric materials applied to a PCB to improve device reliability. These films protect electronics from environmental threats, including humidity, liquids, and corrosive substances.

Different conformal coating materials include acrylic coatings, silicone, epoxy, and Parylene. Polyurethane is another common conformal coating material.

Learn how to choose the best conformal coating

 

 What is Polyurethane Conformal Coating?

Polyurethane coatings are tough, hard, protective layers resistant to solvents and abrasion.

Polyurethane conformal coatings have the following attributes:

  • Moisture and oil-resistant
  • Fungicidal
  • Good flexibility
  • Can be thinned to achieve a chosen viscosity
  • Class F temperature rating (160°C/320°F)
  • Retain excellent electrical insulation properties after the MIL-I-46058 cycling test.

 

Polyurethane Conformal Coating Benefits

Polyurethane can augment devices, extending their lifetime and ensuring they dependably operate wherever deployed.

These coatings exhibit sturdiness and strong resistance to humidity and organic solvents. The tough coatings are resistant to mechanical wear. Additionally, Polyurethane can mitigate the growth of tin whiskers.

 

Polyurethane conformal coating on a PCB

 

Polyurethane Conformal Coatings Applications

 

Polyurethane coatings are ideal in areas with technology that will face excessive chemical exposure.

Urethane coatings protect and insulate motors, generators, relays, transformers, and other components. This coating material is also common in automotive and aerospace environments. Urethane coatings protect these electronics from chemicals and salt sprays throughout temperature fluctuations.

 

What Do Polyurethane Conformal Coatings Protect Against?

The coatings protect electronics from thermal shock, moisture, chemical solvents, and other elements. Compared with other materials, Polyurethane has a lower degree of friction and high abrasion resistance.

 

The Polyurethane Conformal Coating Process

Polyurethane is available as either single or two-component formulations and can be applied with dipping, spraying, and brushing methods. After application, the films are cured to complete the coating process, which takes an hour to several days. Single-component urethanes are easy to apply but take up to days to finalize. Meanwhile, two-component formulations cure within hours. The length of the process is also related to temperature, curing faster at moderately elevated temperatures. UV curing and heat catalyzed, and moisture curing are common methods to cross-link urethane polymers.

 

View a webinar about designing conformal coatings for reliability

 

Polyurethane Disadvantages

As mentioned, Polyurethane conformal coatings have benefits, such as abrasion, thermal shock, and moisture resistance. That said, the coating also has disadvantages. The curing process can be timely and requires a long post-cure time, and moisture impacts the cure rate and cured properties. The coating can also turn yellow with age.

 

Learn How to Choose the Best Conformal Coating for Your PCB

 

The Big Picture

Choosing a conformal coating material extends beyond just looking at the material and application methods. It is important to consider various variables, including the components’ complexity, environmental regulations, and coating rework and removal. Repeatable processes that avoid defects may be important, especially for high-reliability applications.

Please read our definitive guide for more information on choosing the best conformal coating for your PCB. Alternatively, contact our Applications Engineering team for a consultation if you require more assistance. Or, you can learn more about the protection capabilities of coatings.

 
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6 Common Conformal Coating Defects & Their Solutions

June 16, 2020 / by Mallory McGuinness-Hickey posted in Conformal Coatings, Coating Process

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When we say that a chain is only as strong as its weakest link, we aren’t talking about polymer chains – we’re talking about conformal coating defects. Regardless of the type, a single coating defect can affect the long-term reliability of a PCBA or component and must be repaired or removed. This can be costly and labor-intensive.
 

Therefore, it’s best to avoid defects from occurring in the first place. The following is a list of common defects and how to keep them from cropping up during your conformal coating application.

 
 

The 6 Most Common Conformal Coating Defects and Solutions

 

Capillary Flow

Capillary flow, also known as scavenging, occurs when a conformal coating migrates from one area of a PCBA to another, leaving behind an inconsistent, uneven finish on the surface.

Common causes for capillary flow include:

  • The application of too much coating
  • Conformal coating with low viscosity or high surface tension
  • Low surface energy of component being coated

To avoid capillary flow from occurring:

  1. Ensure that the PCBA is entirely clean before coating.
  2. Use solvent-based coatings instead of water-based, and decrease the use of thinners to increase viscosity.
  3. Before coating, heat the board to decrease dry time.

Learn more about epoxy conformal coating.

 

Cracking and Ripples

Cracking and ripples can compromise a conformal coating film, exposing a substrate or PCBA to potential contaminants.

Common causes for cracks and ripples include:

  • Coating that is too thick
  • Thermal shock
  • Coating that has been cured too quickly

To avoid cracks and ripples:

  1. Always apply the coating at an appropriate thickness.
  2. Allow for extra drying time at room temperature.
  3. Consider selecting a coating with a broader effective temperature range.

Dewetting

De-wetting is when a conformal coating will not evenly coat the surface to which it is being applied.

Many things cause dewetting, including:

  • An uneven coating application
  • An improper mixture of two-part materials
  • Residue on the coating surface
  • Variations in Surface Tension and Surface Energy

To avoid dewetting, thoroughly clean the material being coated before application.

Learn more about polyurethane conformal coating

 

a printed circuit board experiencing dewetting

 

Delamination

Delamination occurs when a coating has lifted away from the substrate. This hinders protection because the area below the coating is left exposed.

Delamination has many causes, including:

  • Too thick of a coating
  • Coating not adhering to the previous coating layer
  • Contamination on the coating surface prevented a good bond to the surface

To prevent delamination:

  1. Reduce the thickness of the coating.
  2. Thoroughly clean the substrate before coating.
  3. Apply a “primer material” that can bond with the substrate and material used for conformal coating.

Orange Peel

Orange peel is when a coating appears dull, resembling the skin of an orange.

It is caused by conditions including:

  • A substrate that is too hot
  • Improper coating mixture or solvent ratio
  • A local environment that is too dry during application
  • A second coat has been applied before the first coat is dry

To avoid orange peel:

  1. Apply coating at the specified thickness.
  2. Reduce the viscosity of the coating.

Learn more about conformal coating vs potting

 

Air bubbles, Pinholes, and Foam

Bubbles occur when pockets of air get trapped under a conformal coating layer. Foam is an extreme form of bubbling, and sometimes bubbles burst through the conformal coating, forming a pinhole.

Bubbles, pinholes, and foam happen when:

  • A coating is too viscous
  • The coating is too thick
  • Application equipment has not been setup correctly

To avoid air bubbles, pinholes, and foam:

  1. Use a lower viscosity conformal coating
  2. Ensure the coating is applied at the recommended thickness.
  3. When applying the coating, do so with thin coats.

Why This Doesn’t Happen at HZO

At HZO, we use a conformal coating application method called chemical vapor deposition (CVD) that circumvents these conformal coating issues. Using CVD, we produce uniform, pinhole-free conformal coatings every time. Contact us today to speak to an expert if you want to hear more about our proven technology and processes.

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Conformal Coating vs Potting/Encapsulation - The Pros & Cons

June 11, 2020 / by Mallory McGuinness-Hickey posted in Conformal Coatings, Coating Process

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As the world of electronics continues to grow and evolve, printed circuit board assemblies (PCBAs) find their way into more and more products and industries. Whether you create products for consumers, the automotive industry, the military, or some other field, PCBAs play a big part in your product design. You’ll need to protect them without impeding the rest of your design.
 

You have a few options for coating a PCBA: conformal coatings or potting and encapsulation resins. These organic polymers provide chemical and thermal resistance and electrical insulation to the delicate PCBA beneath them. But that’s where most of their similarities end. This guide will discuss the differences between encapsulation resin and conformal coating and their effects on a PCBA.

 

What’s the Difference Between Conformal Coatings and Potting?

While both potting/encapsulation and conformal coatings protect a PCBA, they do so differently.

Electronic encapsulation seals a PCBA within a thick resin layer to protect substantially against physical shock, chemical exposure, and excellent electrical properties. Usually, this resin is dark-colored, so you won’t be able to see the board underneath it. The resin is mixed with a hardener before application, which allows it to cure a cross-linked polymer.

So, what is potting? While “encapsulation” and “potting” are used interchangeably, potting sometimes refers to the process used for PCBA encapsulation.

Alternatively, a conformal coating is a protective dielectric layer that is non-conductive. It protects from dangers like salt spray, fungus, moisture, and corrosion. The film, composed of epoxy conformal coating, acrylic, or silicone, is very thin and lightweight, having almost no dimensional effect on the PCBA or added stress to the components. Processing and applying this single-component material is easy and versatile, providing flexible options for the finished product.

Learn More About Conformal Application Methods

While traditional coatings are single-component, some newer ones use a two-part process with polyurethane conformal coating to blend the protective aspects of PCBA potting with the flexibility of coatings. Plus, they don’t use solvents, which reduces concerns about volatile organic compounds (VOCs) present in many low-viscosity single-component coatings and adversely affects people and the environment. Fortunately, even those have come a long way, as most manufacturers have worked to reduce VOCs in their coatings.

 

Which Is Better to Protect My PCBA — Conformal Coating or Potting?

To best protect your PCBA, you’ll have to consider several factors of your product and how PCB resin coating and potting contribute to them.

Environmental factors play a significant role in choosing a protective material. Will your PCBA be exposed to any of the following?

  • Extremely high or low temperatures: You will have to consider the way resin can behave during use in extreme temperatures, how sudden or gradual the change is, and how heat could affect production. Resin generates a lot of heat when mixed with its hardener, which can cause damage to the PCBA or the housing if it gets too hot.
  • Water, humidity, or moisture: Some conformal coatings are less waterproof than others. While the resin is typically always waterproof, you’ll have to double-check that your coating is, too.
  • Physical shock: If your component might be exposed to heavy physical shock, the resin can help spread the impact across the material and reduce or eliminate the damage to the PCBA.
  • Mechanical stress: Abrasion and scratches can become problematic in environments like assembly lines and manufacturing equipment, where high speeds and volumes are typical. Resin provides a thick layer to protect against that physical threat.
  • Chemical exposure: If your PCBA could be exposed to harsh chemicals, both resin and coatings provide exceptional protection from exposure and submersion.

While PCBA potting offers more protective benefits, coatings hold the upper hand in design flexibility and can still protect products in everyday environments, like consumer electronics. Only those that are in particularly challenging environments typically need PCBA encapsulation.

 

a printed circuit board being encapsulated with a coating

 

Below are some design factors that factor into the debate:

  • Weight: Resin adds a thick block of material on top of the board, significantly increasing its weight. In many products, heavyweight components aren’t an option.
  • Thickness: Many products can’t function with the added thickness of the resin added to their design.
  • Workability: Since resin is dark and thick, you can’t see through it or easily remove it to rework the board. It could rip up the PCBA if you tried to take it off. Coating, on the other hand, is usually clear, which allows you to see through it and make adjustments if needed. This helps address any conformal coating defects
  • Housing: If the housing of the PCBA doesn’t offer much protection, the resin may be a way to protect it more thoroughly. Coatings are often used as secondary protection within well-built housing.
  • Application: Depending on the design requirements, one option may be better for production. Resin can add risky heat during application and takes longer to cure. Conformal coatings tend to be quick-drying and can be applied in several ways, such as painting it with a brush, spraying it on, dipping the PCBA, and using robotic systems.

Conformal coatings are an excellent way to protect a PCBA from common threats without paying for the added weight and cost of encapsulation.

Here at HZO, we use a coating called Parylene, which is biocompatible — meaning it’s great for the medical devices industry — and extremely thin. It is clear and excellent for waterproofing and liquid protection.

 

Pros and Cons of Potting/Encapsulation

Designers often choose PCBA encapsulation for products in heavy-duty environments, as it protects against many damaging agents.

Some of the benefits of PCBA potting include the following:

  • Provides added protection against chemical, thermal, and physical risks, including water and shock.
  • Offers better performance for high-speed and high-volume work in industrial environments.
  • Has VOC-free options.

Some disadvantages of PCBA potting are:

  • It makes it difficult to inspect or rework the PCBA.
  • Causes possible design issues due to the added weight and thickness.
  • A more complex application process, especially regarding heat and two-part mixing.

Pros and Cons of Conformal Coating

Conformal coating is more popular than potting. It protects many consumer products outside dangerous exposure environments and provides more design flexibility. However, if your product is used in rough applications, it may not offer all the necessary protections.

Here are some of the pros of conformal coatings.

  • Thin and lightweight, offering superior design flexibility and no stressed components.
  • Offers protection from low-level issues like salt spray, dust, moisture, and corrosion.
  • Offers a variety of application methods.
  • Newer options with low VOCs.
  • Long lifespan.

The negatives of conformal coatings include:

  • Offers less robust protection against heavy-duty threats.
  • Contains VOCs within the solvents, though these are becoming less abundant.

Contact Us Today to Protect Your PCBA

If you’re still unsure about which option is best for your PCBA, our expert team of HZO engineers can help. We realize that your needs are just as unique as our coatings, so we will work closely with you to provide custom coating solutions.

To learn more, contact us or call us today at 1-877-757-4496.

 
 
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Parylene - Different Types & Properties Explained

June 5, 2020 / by Mallory McGuinness-Hickey posted in Parylene, Coating Properties

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Parylene is a chemical compound applied to substrates using chemical vapor deposition (CVD). Because Parylene coating deposits onto the surface molecule by molecule, it forms a defect and pinhole-free coating with excellent conformality. Parylene resists chemicals and can protect against caustic substances, acids, corrosion, and more. Unlike conventional conformal coatings, Parylene is ultra-thin, providing superior coverage at 50% thickness. Several types of Parylene coatings enhance its adaptability, all suited for various industrial applications.

 

What’s the Difference Between Parylene Types?

The Parylene types covered in this guide are all characterized by different chemical compositions and physical properties. Parylenes have different levels of permeability, dielectric strength, and other defining qualities. Choosing the best one depends on what application you’re using it for and what substrate you’re coating.

Here are several different types explained, including the best application use:

 
parylene n dimer

 

1. Parylene N

Parylene N consists of a linear carbon-hydrogen molecule structure. It’s the most fundamental, basic form of Parylene, making it suitable for devices with high-frequency use. This type is distinguished by its vacuum stability and low dielectric constant. When going through the deposition process, Parylene N and Parylene C have a higher deposition rate than many other types. This quality makes it convenient for commercial use, although it’s less widespread than Parylene C.

Read more about Parylene N.

Parylene N is also halogen-free. Halogens include elements like fluorine, bromine, and chlorine. This quality generally makes Parylene N preferable to other conformal coatings, as some industries require their coatings to be halogen-free. For example, halogens in electronics can bio-accumulate within living beings and can be toxic to the environment when burned.

The most common applications for this Parylene conformal coating include the following:

  • Printed circuit boards: Most Parylene types protect the delicate inner workings of complex circuitry.
  • Elastomers: Manufacturers use Parylene N to coat elastomers, polymers with weak molecular forces.
  • Electronics: Most types of this material are excellent for protecting electronic devices, whether medical or non-medical.
 
Need to see if HZO Parylene meets your specifications? 

 

parylene c dimer

 

2. Parylene C

Moisture-resistant Parylene C is similar to Parylene N because it contains a carbon-hydrogen molecule structure. However, for each molecule, it possesses one chlorine atom in place of a hydrogen atom. As a conformal coating, Parylene C provides a protective barrier for printed circuit boards. Parylene C is an ideal coating for applications that require corrosion inhibition due to its low permeability.

Like other types, Parylene C is added to a substrate using the parylene coating process, chemical vapor deposition.

Learn more about why Parylene is used

If you have a device that needs high levels of protection, Parylene C is one of the best coatings available. Here’s where you’ll often see it being used:

  • Medical Devices: Parylene C has been used in previous medical device studies as a substrate for peripheral nerve electrodes. A nerve electrode connects neurons to a brain-machine interface (BMI) and records nerve signals.
  • Microelectromechanical systems devices (MEMs): Parylene C is often used to coat MEMs devices, though it can also serve as a structural or substrate material.
  • Caustic environments: Devices that experience constant exposure to caustic substances fare better with a Parylene C coating because of the room temperature coating process, which enables pinhole-free Parylene barriers.
Parylene F (VT-4) dimer

 

3. Parylene F (VT-4)

Parylene F doesn’t see the same commercial use as the other types on this list. However, it still possesses desirable qualities, such as a low dielectric constant and great thermal stability. It also allows for a higher coating density when used in various applications. This Parylene coating is characterized by its fluorination due to having fluorine atoms in its aromatic ring.

Although it’s not as widespread, its properties can serve well for things such as:

  • Field-effect transistors: One study showed that Parylene C and F were used within field-effect transistors to produce copolymer gate dielectrics. The study’s results showed that Parylene copolymer dielectrics offered stable and high-quality performance without requiring extra manufacturing steps.
  • Microelectromechanical systems devices (MEMs): Like Parylene C, the F type also lends itself well to MEMS — especially those with high-temperature requirements.
  • Harsh conditions: Parylene F resists high temperatures and ultraviolet (UV) radiation. Because of these properties, it could serve as a suitable substitute for Parylene C under harsh conditions.

 Learn more about Parylene temperature range

Parylene D dimer

 

4. Parylene D

Parylene D resembles Parylene C in that it substitutes two hydrogen atoms for two chlorine. Both of these materials come from the same root monomer. Parylene D, however, lacks the same ease of use that C does — especially in terms of biocompatibility. It can hold up well when exposed to high temperatures, but it doesn’t work as effectively for coating things like medical devices.

Learn about Parylene optical applications.


Parylene F (AF-4) dimer

 

5. Parylene F (AF-4)

Parylene F (AF-4) possesses high oxidative resistance and UV stability. These properties make it suitable for specialized applications. It can withstand UV exposure without experiencing surface yellowing or degrading, which adds to its durability.

However, creating this conformal coating requires a three-step process. The additional stages increase production costs while limiting the yield, so saving this Parylene for only highly specialized uses is best. These include high-temperature applications and UV radiation protection.

 

Contact HZO for Parylene Conformal Coatings

If you’re interested in coating your devices, HZO can assist you. We serve a range of industries to help device manufacturers meet specifications, no matter the products produced.

Our turnkey solution helps us meet your coating needs by providing industry-leading, state-of-the-art Parylene coating equipment and employing proven material science. We have expertise in Parylene removal and industry-leading Parylene masking automation that reduces the price of Parylene coating services. Combining the entire package, HZO can offer you a high-quality experience with a durable finished product. Contact us today to speak with one of our highly qualified engineers about Parylene coating solutions.

 
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Solving Weather & Water Challenges For Smart Farms

May 12, 2020 / by Mallory McGuinness-Hickey posted in Parylene, Protection Capabilities, Thin Film Applications, Value of Coatings

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It’s a Small World, After All

The world’s population is projected to reach 8.5 billion by 2030, an unprecedented increase approaching fast. This looming surge will compound our current problem – more mouths to feed on a densely packed planet that isn’t growing any larger.

Even as available agricultural land shrinks and natural resources become more depleted, farmers must produce 70% more food by 2050.

Necessity is the mother of invention, especially when it comes to farming. After all, if the agricultural industry doesn’t adapt, we don’t eat. The task at hand for farmers is to produce more food with more precision while working with less.

 

IoT in Smart Farming: Connecting Dots

To adjust to these changes, the industry has introduced technology to agriculture, a practice known as smart farming. Intelligent devices collect and process information about emerging issues and environmental changes, enabling farmers to respond more quickly. Pulling this system together is the Internet of Things, connecting smart machines and integrated sensors to produce data-driven, data-enabled processes.

Information about the fertility of the soil, crop growth, weather conditions, and other variables can be used to track business status, equipment efficiency, and employee performance, offering valuable insights that can be used to optimize agricultural performance. As a result, work, waste, and risk are reduced, while cost management and capabilities are enhanced.

 

Hardware Security Implications in Smart Agriculture Pose Problems

While agricultural devices hold promise, no matter how smart the software may be, the success of the smart farming system is contingent upon how physically secure the hardware is. This is problematic for several reasons:

  • Without adequate protection, sensors can easily be damaged by wear and tear caused by constant exposure to drops, falls, heavy winds, or pounding rain.
  • Typical weather conditions, such as high temperatures, pollutants, condensation, and humidity, can cause immediate failure by a short circuit or a long, unpredictable shutdown due to corrosion.
  • To operate reliably, farm managers need to access information consistently. A single sensor failure could lead to a catastrophic period of downtime at worst. At best, failing devices create the need for continuous maintenance and replacement.
one phone underwater that is still working because of HZO protection and another that is dead because of water damage

 

Protecting Smart Farming Equipment Has Never Been This Important

The onus falls on the agricultural industry to achieve more precision and a higher level of performance as it struggles to meet the demands of our population. To farmers, physically robust hardware is more important than ever.

Weather stations located across fields offer insight into climate conditions, the optimal choice of crops, and potential actions that, when taken, could improve farming capacity. Meanwhile, sensors attached to cattle are helping farmers understand changes in health and activity levels for each animal and, collectively, the status of the entire herd.

Crop management devices produce data about crop health, precipitation, and temperature fluctuations, allowing farmers to mitigate risk and increase yield proactively. This kind of cognizance is gleaned from smart farming sensors, provided these devices can predictably perform in an unpredictable environment.

 

Overcoming Challenges to Device Security In Smart Farming with Parylene Thin-Film Coatings

Considered a “best-in-class” conformal coating in electronic, industrial, medical, and engineering industries, Parylene is a thin-film electronic protection solution that can address agricultural challenges. Applied with a vacuum deposition technique, Parylene coatings achieve dependable coverage free from imperfections like cracks or voids. The coating uniformly conforms to device topography, completely penetrating spaces as narrow as <0.01 mm.

Additionally, Parylene has good heat endurance. For example, Parylene C can offer durable environmental protection for ten years at 80°C. Providing mission-critical protection at thicknesses on the micron level, Parylene can endure temperatures and weather conditions that traditionally have been hurdles for smart farming devices.

If you have been tasked with designing or manufacturing smart farming devices that the industry can depend on, Parylene is an excellent way to achieve critical reliability. Please contact us today if you’d like to learn more about our Parylene solution.

 
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Designing a Waterproof Product With IP Ratings

March 25, 2020 / by Mallory McGuinness-Hickey posted in Protection Capabilities

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The Big Picture: Manufacturers determine IP ratings, not an impartial group. Although these rating systems are useful for comparison purposes, they are not the panacea for rating electronic waterproof design.

 

If you are designing a waterproof product and using IP ratings as a measuring stick, you may want to reconsider. When people think about IP ratings, what they normally understand as “waterproof” are IPX5, IPX6, IPX7, and IPX8. However, this is a misrepresentation. So why do we use IP ratings to measure the amount of liquid protection a device has?

Do IP Standards Measure Liquid Protection, or Are They Just a Marketing Measure?

Consumers have been demanding waterproof electronics for a while now, and in the past, manufacturing marketing teams were happy to deliver what they didn’t necessarily have. Marketing teams, particularly for watches, showcased the word “waterproof” in their messaging. But these watches couldn’t stand up to liquid submersion.

 
one phone underwater that is still working because of HZO protection and another that is dead because of water damage

In an attempt to clear the confusion, the International Organization for Standardization (ISO) replaced the word “waterproof” with “water-resistant.” This happened in 1990 when ISO issued the standard ISO 2281 for water-resistant products.

Nevertheless, a few years ago, commercials appeared with people using electronics in the shower, swimming with them in the pool, and dropping devices in the water – electronics, like smartphones, which, again, weren’t waterproof.  

However, these commercials naturally led to the belief that the advertised products were, in fact, waterproof. However, customers described dropping so-called “waterproof” electronics for as little as 5 seconds, only to witness instant device destruction. The icing on the cake was that many manufacturers refused to mitigate liquid damage in their warranties.  

As you might have imagined, lawsuits ensuedISO tried to clarify again when they replaced the ISO 2281 standard with ISO 22810 to update the content in 2010. 

Now, the term “water-resistant” describes products and the testing protocols created by the International Electrotechnical Commission (IEC) and ISO. Let’s look at some of those protocols now to understand how “waterproof” IP-rated devices are. 

Learn more about NEMA vs IP ratings

 

What’s the Equivalent of IP Rated?

The first thing to know about IP testing protocols is that testing uses pure water only in laboratory conditions while the device is powered off.

Additionally, IP ratings only test for very specific environments.

 

IP Ratings only test for very specific environments

  • Relative humidity range – 20% to 75%  
  • Air pressure range – 86 KPa to 106 KPa 
  • Test samples should be completely new and clean. 
  • Recommended temperature range – 15 C to 35 C 

After testing, manufacturers inspect their devices’ enclosures for water ingress. Some water can even enter an enclosure and pass IP testing – under the condition that the exposure to water does not interfere with device operation or jeopardize user safety.

 

Do IP Standards Hold Up To Real Life?

Below are the requisites manufacturers must meet to deem a device “IP protected.”

The IPX6 standard test confirms that a device has suitable protection against heavy seas or powerful jets of water.

The IPX7 test attempts to determine whether electronic enclosures can provide enough protection from temporary immersion in water. A device will be immersed in water for a half-hour. The temperature of the product and the water cannot vary more than 5 C.

IPX8 tests for continuous immersion are completely subject to the manufacturer’s requisites. At the very least, they should be more severe than IPX7 conditions. 

 

So, if you submerge a product from the box into 1 meter of fresh water inside a laboratory, your bases are covered. But what happens when you step outside the lab?

Learn about other standards, like Mil-i-46058c and UL94 ratings

The IP Rating System Won’t Help When Life Happens

 

There are a few glaring problems when it comes to calling an IP-rated device “waterproof” in real-life scenarios:

  • Device pressure is affected by how it enters the water for IPX7 and IPX8 tests. Fluctuations in pressure can affect the depth and time a product can be submerged in water.
  • Temperatures in bathrooms, bathtubs, steam rooms, or saunas will probably exceed the specific temperature range that manufacturers test for, making the physical seals meant to protect electronics less efficient at protecting the device.
  • The tests use fresh water. Freshwater starkly contrasts the water that devices typically encounter, like tap water, swimming pools, saltwater, bathtubs, or toilets.
  • Chemicals commonly used, like perfumes, oils, hair dyes, and solvents, can eat away at the mechanical parts and seals protecting a product, dragging the water-resistance level down.
  • The fact that a device can be placed under 1 meter of water is great, but in the real world, products will probably fall to the bottom, voiding the guarantee that water will not ingress.
  • The devices don’t have to be on during testing – if an electronic device is powered on underwater and is running programs, its internal temperature and pressure will increase, negatively affecting the depth of water the product can withstand. 

Learn about hydrophilic coatings.

 

How to Design a Truly Waterproof Electronic Device

If you want a waterproof (not “water-resistant”) device, you need Parylene conformal coating. As we explained above, commonly used mechanical seals don’t cut it.  

Parylene is a polymer that coats the circuit boards powering your devices from the inside out. It doesn’t add thickness or bulk to devices that other conformal coatings do, and our Parylene can nullify water damage and last up to 20 years.  You can learn more about Parylene and our Parylene coating process here. 

Learn more about our coatings.

Not All Devices HAVE to be Completely Waterproof

 Although the IP rating standards are nebulous, they’re still useful for comparison, and many manufacturers require IP testing for devices that aren’t completely mission-critical. That’s why plasma-based nano coatings are sought out by engineers looking for affordable, ultra-thin conformal coating –  they can meet any IP rating reliably and with scale.  

But we digress. So, is IP57 waterproof? The answer is no; it is just water-resistant. When you consider your mission-critical waterproof electronic design, remember that you aren’t building products for a lab; you’re building products for life on life’s terms.   

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