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PARYLENE DEPOSITION PROCESS

Parylene Coating Process Explained:
How it Works, Variables, Illustrations, Pros & Cons

Increase Electronics Reliability, Performance, and Lifetime in Numerous Applications with a Parylene Coating

Read more about Parylene coating properties.

Meanwhile, other favorable properties (such as high purity, defect and pinhole-free films, and excellent conformality) result from the Parylene coating method.

 

 

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Understanding the Parylene Deposition Process


Parylene is applied with chemical vapor deposition (CVD). When used for Parylene deposition, CVD converts dimer (raw Parylene coating material in powder form) into a gas that deposits onto components, forming coatings that provide excellent corrosion, barrier, and insulation protection. The Parylene chemical vapor deposition process is summarized as follows:
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Dimer is loaded into a vacuum chamber to sublimate into a gas without transitioning into a liquid state.

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After sublimation, the dimer gas passes through to the next stage of the deposition process by flowing through a pyrolysis chamber.

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The gas will be heated to a temperature range of 500 to 700° C to split the dimer molecules and create a monomer vapor.

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The monomer vapor is then drawn into a depressurized chamber, creating a vacuum.

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The chamber, held at room temperature, polymerizes the monomer vapor, conformally coating all surfaces it lands on, including edges, crevices, and other topography.

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The vacuum pump that draws the Parylene vapor into the deposition chamber also pulls the gas exiting the chamber into a cold trap.

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This cold trap will solidify the Parylene for proper disposal.

Parylene N Chemical Change Process

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di-para-xylylene
(dimer)

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para-xylylene
(monomer)

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poly(para-xylylene)
(polymer)

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Parylene deposition equipment is critical to any Parylene coating process

Time to consider throughput, chamber size, and footprint. 

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Parylene Coating Process Overview

Several processes before and after the Parylene coating application are required to complete the film deposition. A general overview of some of these processes is below:

Cleanliness

Surface Preparation

Adhesion Promotion

Masking

Demasking

Parylene Coating Inspection

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Speak to an Engineer About Parylene

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Challenges in the Parylene Coating Process

Delamination

Rework

Long Run Times

How long does Parylene Coating Take?

The answer is that it depends. Parylene types have unique chemical compositions that affect the deposition process. For example, Parylene N deposits more slowly than Parylene C. Additionally, D deposits faster than C, but it can be more challenging to control uniformity within the coating chamber. Parylene film thickness is another variable. Thinner coatings entail shorter coating times.

There are multiple issues to balance when trying to speed the Parylene deposition rate, such as:

  • Increasing the deposition rate
  • Decreasing the coating time
  • Ensuring coating thickness uniformity throughout the chamber
  • Ensuring coating quality throughout the chamber 
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Silicone

Machine Spray Method

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Parylene

Vacuum Deposition Method

Courtesy of CALCE,  University of Maryland

Parylene CVD Advantages

Because Parylene deposits as a vapor that wraps around components, even at tight corners, with minimal changes in thickness, ensuring superior coverage compared to traditional conformal coatings.

Silicone coating has been applied in the accompanied image with uneven coverage. The darker surfaces show where the film has settled, while the lighter edges on each of the leads show where it is thinly applied. Parylene is wrapped completely around the part on the right, with even thickness all around.

Parylene Coating with HZO

Despite the many benefits of CVD, the Parylene coating process can present challenges for OEMs who need to ramp up to mass production or cut costs, but this does not have to be the case. 

HZO is a Parylene supplier serving all industries with high throughput, turnkey coating solutions that decrease cost and improve quality and speed. Please visit our services page, contact us with questions, or get a quote. 

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Additional Resources

Download the HZO Parylene Datasheet
Datasheet

Download the HZO Parylene Datasheet

Learn About Corrosion Resistance From An Industry-Leading Engineer
Webinar

Learn About Corrosion Resistance From An Industry-Leading Engineer

Learn About HZO Coatings With Our Resource Page
Resource

Learn About HZO Coatings With Our Resource Page

Learn About the Parylene Process With Our Resource Page
Resource

Learn About the Parylene Process With Our Resource Page

Learn About Parylene Properties With Our Resource Page
Resource

Learn About Parylene Properties With Our Resource Page

Understand Parylene's Benefits for Optical Applications
Blog

Understand Parylene's Benefits for Optical Applications

Parylene Thickness - How Much is Enough?
Blog

Parylene Thickness - How Much is Enough?

Understand Parylene Masking
Blog

Understand Parylene Masking

Learn How to Remove Parylene Coating
Blog

Learn How to Remove Parylene Coating

Download a Parylene C Datasheet and Learn About the Coating
Blog

Download a Parylene C Datasheet and Learn About the Coating

Understand More About Parylene's Superior Chemical Resistance
Blog

Understand More About Parylene's Superior Chemical Resistance

Learn About the Benefits of Parylene's Biocompatibility
Blog

Learn About the Benefits of Parylene's Biocompatibility

Download a Parylene N Datasheet and Learn About the Coating
Blog

Download a Parylene N Datasheet and Learn About the Coating

Is Parylene Right For Your Project?
Blog

Is Parylene Right For Your Project?

How HZO Makes Parylene Scalable
Blog

How HZO Makes Parylene Scalable

Learn About Parylene
Blog

Learn About Parylene

How Does Parylene Perform in Extreme Temperatures?
Blog

How Does Parylene Perform in Extreme Temperatures?

Why is Parylene Coating Conformal?
Blog

Why is Parylene Coating Conformal?

The Illustrated Guide to CVD
Infographic

The Illustrated Guide to CVD

Learn How To Incorporate Conformal Coating Into Your Manufacturing Process
Webinar

Learn How To Incorporate Conformal Coating Into Your Manufacturing Process

Parylene Coating for Reliable Product Design Webinar
Webinar

Parylene Coating for Reliable Product Design Webinar

Download the HZO Parylene SDS
Datasheet

Download the HZO Parylene SDS

Learn How to Bring Parylene Deposition In-House
Technical Paper

Learn How to Bring Parylene Deposition In-House