The Parylene Deposition Process

Parylene coating is applied onto a substrate or material through a vapor deposition process. Depending on the Parylene variant and required thickness, Parylene typically deposits at a rate of about 0.2/mils per hour. A Parylene machine run can vary from as little as 1 hour to over 24 hours.

The process begins with raw dimer in a solid state being placed into a vaporization chamber. The dimer is heated to 150°C and vaporized into a dimeric gas. Very high temperatures allows for sublimation and the splitting of the molecule into a monomer. Then, the monomer gas deposits on all surfaces as a thin, transparent polymer film. The coating effortlessly penetrates crevices and tight areas on multi-layer components, providing complete and uniform encapsulation. The final stage of the Parylene deposition process is the cold trap. The cold trap is cooled to between -90ºC and -120ºC and is responsible for removing all residual Parylene materials pulled through the coating chamber.

The Parylene deposition process is relatively simple to understand but tough to master. A thorough understanding of the process is key to controlling thickness and ensuring a successful coating cycle.