I have an electronic assembly that is heat sensitive. Due to the incorporation of a CR3032 coin cell battery, it can survive being heated to a maximum of 60 degrees C.
I want to coat this assembly in a biocompatible, waterproof plastic. This layer will be the ultimate barrier to moisture between my device and a biological environment.
At the moment I am using parylene-C, which performs admirably, but is very expensive.
Various species of thermoplastic promise to perform just as well, at dramatically lower cost, but I don't know how I'd apply them without damaging my battery.
My question to you is, how could I coat my circuit in a thermoplastic without thermally damaging it, and without spending more than a few dollars per unit?