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.
The development of our coating technology began in 2007. We've come a long way since, filing more than 200 patents and protecting millions of digital devices. Today, we want to..
Biocompatibility is vital to medical device safety. It ensures implants and other devices can be used in and on the body with minimal adverse reactions. Medical devices must be..
Parylene coatings present unique challenges when it comes to rework and removal. They often outperform other conformal coatings. Parylene has better barrier properties, uniform..
Advanced driver assistance systems (ADAS) continue to expand in features and functionalities. Standard offerings may include adaptive cruise control, park assist, blind-spot..
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..
What is Parylene? Is it Right For My Project? Parylene forms high-performance thin-film coatings. There are several types, like Parylene N, C, and D. Each has unique chemical..
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..
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..
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..
In the world of protective coatings, Parylene is a standout. Its unique, beneficial properties make it a great choice. Many Parylene types have distinct properties, like Parylene..
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..
The development of our coating technology began in 2007. We've come a long way since, filing more than 200 patents and protecting millions of digital devices.
Today, we want to nod to our origin story. We also want to introduce, at a high level, a key material that is a building block of our technology.
Parylene (or Poly(p-xylylene) as it’s also known) is a protective coating. It's deposited using a chemical vapor deposition process. The material is a moisture-resistant, dielectric thin film barrier. It has been used for over five decades on many corrosion-resistant products. Parylene is biocompatible, has superior barrier properties at 50% thickness and is chemical-resistant. Think big. Think powerful. Parylene has been protecting equipment and products in some of the world's most advanced industries for decades.
HZO has developed its proprietary technology using Parylene as a building block. Over the years, it has improved its chemistry and processes. It also automated its Parylene masking and removal equipment. These innovations form a unique and powerful conformal protective solution.
Parylene Overview
So why have most people never heard of it? A major obstacle to wider adoption of Parylene is its high cost. This affects many products, including consumer devices.
The Parylene deposition system and its raw material are expensive. There have been challenges with scalability, manufacturing, and device complexity. There has also been a manual process for masking and demasking sensitive areas that need protection from protective layering.
To the credit of Parylene companies that have been in that market for much of this journey, the technology has improved dramatically over time. The material has a sterling reputation in certain markets where development has been focused. But what about other industries that need the same kind of powerful protection?
HZO Parylene Coating Equipment Broadens the Scope
HZO has expanded the use of this powerful, organic material. It has made it available to companies and manufacturers that had not considered it an option until now. The application’s utility is what separates HZO from other companies in the Parylene space.
We talk a lot about the power of the Total HZO Solution. This includes more than our thin-film protective layering technology. That technology protects digital devices from corrosive liquids. It also includes advances in equipment, integration, and specialized processes. These are required to protect some of the world's most complex digital devices. HZO is a leader in custom solutions for digital devices. Years of work on the technology have made it so. Parylene is part of that solution.
Our ongoing innovations benefit every company we work with. HZO has made Parylene's benefits more accessible and affordable than ever. As a result, more sweat and corrosion-resistant products are reaching consumers. The change in performance is starting to get noticed, and the cry for better protection on consumer devices has never been stronger.
Biocompatibility is vital to medical device safety. It ensures implants and other devices can be used in and on the body with minimal adverse reactions. Medical devices must be highly biocompatible, as they often contact the body's internal tissues and fluids.
Parylene's biocompatibility is crucial for its use in medical devices. Additionally, Parylene is physiologically non-reactive and isn't toxic.
Parylene's Biocompatibility
Medical professionals and device makers rely on strict biocompatibility testing for safety. They follow established standards, especially ISO 10993 and the USP VI Standard.
A complete analysis of Parylene shows it is biocompatible. It meets the strict standards for medical device use. Third-party sources have tested the material, and it causes no harm to tissues or body fluids. Parylene's chemical inertness makes it compatible. It provides a safe interface between the device and human tissue.
Why is Parylene Biocompatible?
Parylene's chemistry and structure make it biocompatible. It meets the USP's highest, Class VI, biocompatibility standards. Parylene has passed the USP's strict tests, described here. Also, it has a proven track record of reliable performance in the medical device industry.
Biocompatible Parylene Coatings Last
Decades of use show Parylene coatings maintain their performance and integrity. Bodily fluids, varying pH levels, and enzymes do not reduce their effectiveness. Parylene-coated medical devices are vital. They provide reliable, long-lasting protection and function.
Parylene's uniform, pinhole-free coating does more than protect. It provides a reliable interface between the device and the body. So, encapsulated medical components can serve patients for as long as they are used. The difference is not just in Parylene's inertness. Parylene can also resist the harsh conditions of the human body.
Below, you can see a Parylene-coated Raspberry Pi computer running underwater in HZO’s lobby. As of the date of publication, this computer has been running fully submerged in tap water for over two years now:
Parylene Versus Other Biocompatible Materials
Parylene often stands out for its unique properties. So, it is a good biocompatible material for medical uses. But, a range of alternatives exists. They include silicone, Teflon, and various medical-grade metals and polymers. Each material has a unique set of traits best in certain conditions.
Parylene is known for its great chemical resistance. It can also form pinhole-free coatings at a micron-level thickness. This lets devices work reliably in the harsh human body. Parylene coatings are ultrathin. They keep the feel and function of the underlying material. This is a big advantage over bulkier options like silicone rubber or polyurethane.
Parylene vs. Stainless Steel
Consider Parylene versus stainless steel, which is a common choice for implants. Stainless steel is strong and fatigue-resistant. But it can't match Parylene's ability to conform to complex shapes. The difference shows in applications needing a seamless coat over complex parts. Here, Parylene's conformal nature gives a uniform layer. It fully isolates the parts from the body's fluids and tissues.
Parylene vs. Teflon
Unlike Teflon, a popular biocompatible material, Parylene is PFAS-free. It is REACH and RoHS compliant, and its ability to maintain physical integrity under sterilization methods boosts its comparability.
The Limitations of Biocompatible Parylene
However, Parylene is not without its limitations. Parylene has great barrier properties and electrical insulation. But, its mechanical strength is not as good as that of metals or ceramics. This property requires careful thought in load-bearing implant uses where strength is vital. Also, the Parylene application process uses chemical vapor deposition. It's very effective but may complicate the manufacturing workflow. Simpler methods, like dip or spray coating, are used for silicone and latex.
Other materials may have specific advantages, like higher tensile strength or elasticity. But, Parylene's combination of properties often justifies its selection. It depends on the intended use, performance, and regulatory standards. Manufacturers must balance performance and material costs. They also consider the complexity of application methods for producing and using medical devices.
Parylene is highly resistant to moisture, chemicals, and other environmental factors. The coatings protect medical devices in and on the body at 50% of the thickness of conventional conformal coatings, reducing product bulk and weight. Also, Parylene has very high dielectric strength, up to 7,000 V/mil. This ensures that electrical components can function uninterrupted by external stimuli.
Parylene's conformal coating attributes ensure a uniform, pinhole-free application. It adheres to every contour of the complex geometries in medical devices. This ensures complete encapsulation with no areas left vulnerable. Parylene's coating uniformity greatly improves device protection.
Chemical Resistance: Parylene surpasses many materials in its resistance to corrosive bodily fluids.
Dielectric Strength: Parylene N has an extremely high dielectric strength of 7,000 V/mil
Biocompatibility: Parylene causes minimal tissue reaction. It compares well to common biocompatible materials.
Barrier Protection: Parylene's seamless coatings provide unmatched barrier protection. Porous materials, like silicone foams, cannot match it.
Common Uses for Parylene in Medical Settings
Parylene coatings have established their utility in a wide range of medical devices. They improve protection and longevity. Here are some use cases for Parylene:
Parylene-coated needles and cannulas have less friction. This makes them easier to insert, which is more comfortable for patients.
Parylene coatings improve stents. They prevent corrosion and reduce friction, aiding in their insertion and long-term performance in the body.
Diverse biomedical applications capitalize on Parylene's biocompatibility. It is present in both in vivo and in vitro environments. These include surgical instruments, cochlear implants, and diagnostic equipment sensors.
Partner with HZO for Your Next Medical Project
Do you have any questions about Parylene or what it can do for your next project? Please reach out to our team. We’re standing by to answer your questions and help you determine your next step.
Parylene coatings present unique challenges when it comes to rework and removal. They often outperform other conformal coatings. Parylene has better barrier properties, uniform coverage, and performance in thinner layers.
Additionally, Parylene's chemical resistance can withstand corrosive gases and liquids. It also performs in extreme temperatures and high electrical activity.
Want to know if HZO Parylene meets your specifications?
But, the properties that make Parylene the "gold standard" of conformal coating can also make it hard to remove. Thankfully, you can use methods to remove and rework Parylene when needed.
When Do You Need to Remove Parylene?
From time to time, it is necessary to rework or remove coating. Sometimes, job specifications change or a Parylene vendor incorrectly applies the coating.
What is Parylene Delamination?
One example of poor application is Parylene delamination. This is when 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 coatings. It must be avoided at all costs. Even partial lifting can render the protective coating useless.
What Causes Parylene Delamination?
Many causes of Parylene delamination exist. One is demasking, a standard process. It creates a need for high-quality inspections after production. Other causes include:
Coating porosity: A vapor pressure difference creates a risk of moisture intrusion into the substrate. Pressure fluctuations and temperature changes create osmotic pressures. These separate the coating from the component.
Incompatible materials: The Parylene coating must bond with the component surface for successful coverage. When the Parylene and the surface are incompatible, they create incongruous surface energies. This causes minimal bonding.
Contaminated surfaces: Improperly cleaned component surfaces do not support adhesion.
Regardless of the reason, the resulting Parylene removal must be efficient and safe. It must protect the coated substrate's integrity.
The following methods are popular ways to approach Parylene removal.
How Do You Do Mechanical Parylene Removal?
Parylene's strength and uniformity make it tough to remove. So, be careful with mechanical methods. They may damage the final product. However, Parylene is a soft polymer. So, mechanical methods may remove it.
Methods like picking, cutting, and scraping are effective. But, they may damage components, substrates, and delicate track lines. This type of removal requires considerable attention and care. Good spot removal is possible with proper masking. But, mechanical methods may be unreliable for larger surfaces.
How to Remove Parylene with Micro-Abrasion
Micro-abrasion is a process performed with automated or handheld systems. It targets a specific area by blasting the Parylene coating with inert gas or dry air and abrasive media. This removal method is suitable for both whole board and spot removal. It is generally easy to put in place, quick, cost-effective, and environmentally friendly.
Can You Use Thermal Removal With Parylene?
Parylene can withstand high temperatures. But, a high-temperature oven or soldering iron can remove it in small, specific areas. As heat is applied, the coated component rises from the board and lifts off.
This technique may be adequate for small repairs. It is less reliable for large surfaces. But, it can still be effective for some jobs. However, residues and discoloration may occur. Parylene's high melting point may damage heat-sensitive substrates. Thermal removal can be hard to manage. It's not recommended without Parylene experts' help.
Which Chemical Can Remove Parylene?
Parylene is chemically inert, resisting chemical degradation. But, one chemical has been used to strip Parylene from substrates and components. It is a colorless organic compound, tetrahydrofuran (THF), with the formula (CH2)4O. This solvent softens the Parylene coating. It temporarily loosens the bond between the substrate and the coating. At this point, the Parylene can be lifted off with tweezers. THF can remove Parylene, but it may damage the coated part. Use the solvent only for complete coating removal. For the security of the components under the coating, consider other removal methods 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 is cost-effective for complex removals. It gives better results. It can also service 3D devices and Parylene-free areas.
Conclusion
There are many effective methods to remove Parylene should the need arise. Each method has its strengths. So, you must know your options. Then, choose the best method for your project.
If you need Parylene removal or want to discuss your project with experts, please message us today. Removing Parylene can be tough. But, a skilled company can simplify and lower the cost of the job. We can help with scalable Parylene equipment and Parylene masking automation. We can also address concerns about the cost of Parylene services.
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.
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.
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
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:
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.
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
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.
Parylene forms high-performance thin-film coatings. There are several types, like Parylene N, C, and D. Each has unique chemical traits for different uses. Across all types, Parylene has excellent dielectric strength and unmatched barrier properties. The coatings resist corrosive gases, moisture, and solvents, ensuring product longevity.
Parylene coatings provide seamless coverage that is defect- and pinhole-free. The CVD process polymerizes and deposits them onto components at around room temperature. The coatings are free of defects and pinholes, which are ideal for critical applications where reliability and performance matter. Parylene is used in medical devices, aerospace parts, and advanced electronics for these reasons.
Why Do Engineers Use Parylene Coating?
Parylene is a unique conformal coating. Its properties give it superior performance in many applications. Parylene coating is recognized for its impressive dielectric properties, providing exceptional electrical insulation. It can work well in many electrical and electronic contexts, protecting against short circuits and other hazards.
Parylene also exhibits robust chemical resistance, preserving components in corrosive environments. Chemical agents find it hard to penetrate Parylene's molecular structure. This ensures the longevity and reliability of coated devices.
Another notable attribute is Parylene's moisture and vapor protection. Parylene forms a seamless barrier when applied, defending against water and moisture ingress. Preventing such contamination is vital to keeping components functional. This is especially true for those in high-humidity areas or subject to sudden temperature changes.
Then there is Parylene's thermal stability. Parylene's composition lets it withstand extreme temperatures. The coating keeps its physical and chemical properties across a wide range. Parylene can endure both the bitter cold of cryogenics and the intense heat of aerospace engines.
Parylene's versatility makes it more than just a protective coating. It is a strategic ally for industries where durability and performance are vital. Parylene-coated components work well. They are safe from environmental damage. Thus, using Parylene as a protective solution is not just a preference. It is a choice based on its proven ability to protect and preserve.
In electronics protection, Parylene is a shield against moisture and threats. The coating protects sensitive circuits from humidity, corrosive gases, and contaminants. Everyday devices, from smartphones to satellites, benefit from such defense. It ensures they work and last longer.
Why is Parylene Used in the Medical Industry?
Within the medical industry, Parylene's biocompatibility and chemical resistance make it indispensable. Parylene creates a barrier between the device and the body, making medical treatments safer and more reliable.
Parylene can make UAVs more lightweight, improving battery performance. Also, Parylene protects PCBs and components from humidity, weather hazards, and pollution.
Parylene improves the reliability of electronics exposed to high temperatures and abrasive conditions. Its chemical resistance helps automotive electronics withstand oils, cleaning fluids, and antifreeze. Parylene is also a green coating compliant with Prop 65, REACH, and RoHS.
Watch a video about why automotive OEMs use Parylene:
Why is Parylene used in LED Systems?
Parylene keeps LED brightness and color consistent over time and protects outside displays from weather damage. The thin coatings make it easier to mount displays as well.
In the military, Parylene coatings protect advanced defense equipment. They ensure mission-critical applications remain reliable in tough conditions. Parylene meets the MIL-I-46058C specification.
Parylene makes gadgets more durable. It helps them resist wear and tear from daily use. Consumer electronics manufacturers can use Parylene coatings to meet any IP rating.
Different applications need different Parylene types. Each has unique properties, suitable for various uses. Manufacturers might choose Parylene N for electronics needing a dielectric layer. Parylene C is better where moisture and gas ingress are concerned. Parylene D, though less popular, can withstand high temperatures Parylene N and C can't.
Parylene N
Parylene N can penetrate and coat minute spaces effectively. This feature creates coatings that can evenly cover complex shapes on electronic parts. Parylene N has no chlorine atoms in its molecular structure, and the coating has a high dielectric strength.
- High dielectric strength - Excellent crevice penetration - Good for delicate electrical components
Parylene C
Parylene C has a chlorine atom, altering its properties. This change gives Parylene C lower moisture and gas permeability. With enhanced barrier properties, Parylene C protects medical devices from bodily fluids and sterilization.
- Superior moisture and gas resistance - Good for corrosion protection - Often used for medical equipment
Parylene D
Also, we encounter Parylene D. It has two chlorine atoms in its structure. This constitution gives Parylene D greater thermal stability than Parylene N and C, useful in high-temperature applications. But, Parylene D is less commonly used than its counterparts. Its applications can be specific and rare.
- Greater thermal stability - Good for high-temperature environments - Narrower range of applications
Why Choose Parylene Over Other Conformal Coatings?
Parylene has distinct differences from other coatings like silicon and epoxy. Parylene's unique chemical vapor deposition process gives it a 100% conformal coating. This provides a strong barrier against moisture, chemicals, and extreme temperatures. This contrasts with silicone coatings. They are usually applied by brushing, dipping, or spraying. These methods can cause inconsistencies in coating thickness and performance.
Durability, too, distinguishes Parylene from other coatings. Parylene's strong molecular structure makes it durable under stress. This gives it a long lifespan. Meanwhile, epoxy coatings are strong but can become brittle over time. They also lack Parylene's ability to stay elastic and flexible in varying temperatures.
When you need ultra-thin, uniform coatings, Parylene is often best. It can coat at micron-level thicknesses without compromising coverage or protection. This lets manufacturers meet design specs without adding weight or changing dimensions. Also, Parylene's biocompatibility makes it vital for medical device coatings that will contact bodily tissues or fluids.
Silicone and epoxy coatings work well in many uses. But, they may not meet the strict standards in aerospace and medical industries. There, even the smallest failure can have catastrophic results. In such cases, choosing Parylene proves its unmatched performance in critical uses.
Bottom Line – Is Parylene Right for My Application?
Should you use Parylene for your next project? First, ask yourself how much you value reliability and performance. Then, answer the question.
Consider Parylene when failure is not an option.
Parylene may also be your best bet when you need lightweight protection. This includes aerospace and automotive markets that must support fuel efficiency.
Some products do not need such strong barrier properties and corrosion resistance. It's not necessary to ruggedize all devices. In these cases, it would raise costs, delay new products, and serve no purpose.
It is not always necessary to achieve critical, reliable protection. But when it is, Parylene coatings are the best defense. Have questions? Speak to an engineer.
Watch the webinar about Parylene’s proven corrosion resistance.
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.
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.
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.
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.
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
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.
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. But, Parylene dimer and labor can be costly. So, design teams may hesitate to use them for high-reliability protection.
Many see Parylene coating as hard and costly to apply despite its proven performance. So, many assume it is suitable only for extreme, mission-critical situations. These include military, medical, and aviation applications.
What Are Other Common Misconceptions About Parylene?
Masking is too complex and time-consuming to bother with
CVD coatings (chemical vapor deposition) entail long batch times. This raises labor costs and lowers throughput
These assumptions are unfounded. But Parylene coating is the most costly of all conformal coating options. So, choose a partner who can work within your budget. They should also help you estimate potential costs.
How to Calculate the Cost of Parylene
At HZO, we have crafted processes and procedures to cut the costs of Parylene coating. Yet, three factors are pertinent to the price regardless of whom you work with.
Parylene Type Affects the Cost
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 enable better UV and heat resistance. Consult HZO, a Parylene coating service, to find the best Parylene type for your project.
Parylene Masking Influences Price
Masking can be more complex with Parylene coatings, resulting in increased labor. However, changing your product's design can reduce costs. It would make it easier to coat and mask. HZO has industry-leading automated and semi-automated masking and demasking equipment. Working with us simplifies the process and cuts costs.
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. Each coating run will have a fixed cost. But, you can optimize the number of components coated in each run to lower the coating cost per item. (Meanwhile, HZO has built proprietary coating equipment that can house more items at once per run than any other Parylene company. This minimizes costs per 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?
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
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.
In the world of protective coatings, Parylene is a standout. Its unique, beneficial properties make it a great choice. Many Parylene types have distinct properties, like Parylene C, N, and F (VT-4 or AF-4, for example). By choosing a type, you can tailor Parylene to specific performance requirements.
How Does Parylene Thickness Affect Coating Properties?
The type of parylene dictates coating properties, while the thickness of the Parylene conformal coating determines its protection level. This includes electrical insulation, mechanical protection, and chemical resistance.
Electrical Insulation - A thicker coating usually has a higher dielectric strength. It can withstand greater electrical stress and prevent current leakage.
Mechanical Protection - Thicker coatings shield the substrate from damage, like abrasion better. They also resist mechanical stress.
Chemical Resistance - A thicker layer can delay the penetration of aggressive substances. It can also protect the substrate from corrosive environments for longer.
How Thick Does Parylene Need to Be?
How much Parylene do you need for your application? The answer depends on your design, choice of Parylene, and what environment you need protection from.
For example, applications requiring higher dielectric strength will require thicker Parylene layers, and this can be from 25 microns and above.
On the other hand, applications that are exposed to minimal moisture will typically require a coating greater than 2 microns.
What is the Best Parylene Thickness for My Industry? - Some Examples
Medical implants - Thickness varies depending on the use case and environment but typically can be seen in the 10 um to 20 um range.
Electronics - Thickness can vary from 2 microns up to and beyond 25um depending on the use case and environment of the product.
Aerospace components - A thicker application, often greater than 25 microns, offers enhanced protection from extreme environmental conditions.
How Thick Should Parylene Be in Different Environments?
Different environments demand specific barrier protection capabilities and, thus, different coating thicknesses. Analyze the threats in your application environment and the coating specs you must meet. Then, you can pinpoint the Parylene thickness you need. Here are some examples:
Moisture and Humidity - A Parylene coating as thin as2 microns can offer surface protection from moisture.
Submersion Protection: A Parylene coating from 5 microns and above will be able to protect most productions from freshwater submersion
Temperature and Humidity: Products that will experience a range of temperature and humidity changes over the lifetime of the product are typically coated at a thickness greater than 15 microns
Chemical and Solvent Resistance: Chemical exposure typically necessitates coatings over 10 microns to prevent permeation and ensure the integrity of the covered components.
Physical Abrasion: Parylene is a soft polymer and while it will not wipe off, it is not suitable to an environment where there will be continual abrasion of the coating.
By analyzing the environmental threats in your application environment and the coating specifications you must meet, you can pinpoint the Parylene thickness you need.
How Do You Measure Parylene Thickness?
Coating thickness can be measured with various techniques. The industry standard method that HZO employes is to use spectral reflectance. This is done for every run in every one of our facilities. Additional methods such as contact Profilometry and Ellipsometry can also be used.
Spectral Reflectance
Spectral reflectance is used for measuring coating thickness by examining the interaction between light and matter at various wavelengths. Spectral reflectance measures how much light reflects from a thin coating over a range of wavelengths and is a non-destructive, non-contact method. Spectral reflectance is commonly used for coatings that range from around 1 to 50+ microns, most often on glass slide witness coupons and sometimes directly on a coated product with sufficiently flat and reflective surfaces.
Contact Profilometry
Contact Profilometry
With contact profilometry, a physical probe moves across the coating surface, registering variations in height to reveal thickness disparities. This mechanical method is respected for its accuracy and ability to produce detailed surface topography maps. However, the very contact nature of this technique might induce damage or introduce deformations to Parylene films, presenting a significant limitation so this Is not used on a a daily basis.
Ellipsometry
Ellipsometry, a non-destructive optical method, analyzes polarized light reflected from the coating surface. The ellipsometry tool infers film thickness by interpreting changes in the light's polarization state. Light interaction with the substrate complicates this analysis, often requiring the tool to perform complex calculations and it needs meticulous calibration to ensure accurate results, especially with non-uniform surfaces. Ellipsometry is more often used for sub-micron thickness coatings, especially on silicon wafer witness coupons.
At HZO, quality is top of mind. Since our inception, we've coated millions of components and haven't had one product return due to coating issues. Watch this video to learn more about our coating process.
Choose HZO as your Parylene Coating Partner
Are you wondering how thick the coating should be on your next project? No problem. Book a DFM consultation and speak to an engineer. They will tell you the next steps.
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.
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 SecurityInSmart 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.
