Improved Parylene Adhesion on Flex Circuits

Parylene has been used for decades to protect PCBs from harsh environments. Flex ciurcuts made of polyimide or Kapton are being used more and more to make wearable electronics. One of the steps involved in the parylene coating process is an adhesion promotion step to help parylene stick to the substrate. With traditional adhesion promotion processes, parylene can have problems sticking to flex circuits. The R&D engineers at VSI Parylene conducted a series of experiments to create the optimal adhesion promotion solution for parylene onto polyimide substrates. A variation of chemistries, solvents, concentration, time and temperatures were variables in the experimental design. The ASTM D3359-09ε2 adhesion measurement by tape test method was used to quantify parylene adhesion onto polyimide substrates after adhesion promotion and parylene coating. A formula with an average of 90% adhesion (3B classification) was achieved, with samples of up to 100% adhesion (5B) demonstrated, see Figure 1. While A-174 samples result in complete delamination (0% adhesion, 0B), KAPhesionTM provides a verified solution to the polyimide adhesion promotion problem. To find out more or to request a sample coating run, please contact www.vsiparylene.com.

Step 1: Identify problem with corrosion or environmental damage

Are you having problems with environmental damage or corrosion on a circuit board or flex circuit?  We love to learn about new ideas where parylene can enable parts and applications. Contact VSI Parylene to discuss our parylene deposition process.

Step 2: Send parts to VSI Parylene for coating

If your application looks like a good fit for parylene protection, you can send parts in and we will provide parylene coating as a service. 

Step 3: Part returned, test for improvment

VSI Parylene will send parts back to you and you can test to make sure the coating made an improvement.  If the coating works, let us know and we can talk about ways to ramp up the process if needed. 

Happy tinkering!