Parylene Chemical Resistance Properties – Overview

Posted on January 21st, 2022 by

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 industries ranging from medical devices to automotive.

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
2-Propanol (IPA)

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, as well as 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.

Mallory McGuinness

As a veteran writer with over a decade of writing experience, Mallory McGuinness has spent the last two 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.

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