LASP’s instrumentation always has used silicone-free polymerics, including conformal coating materials. We are also extremely careful when it comes to our polymerics, and we have learned to have favorites over the years.

We have almost exclusively used Arathane 5750 (https://krayden.com/technical-data-sheet/hunts_arathane_5750_ab_lv_tds/) for conformal coating. (Though there are exceptions that I don’t want to go into here.)

Any polymeric material, though, can be a source of contamination through outgassing, both in ambient environments (room temp, 1 Atmos.) and vacuum (thermal-vacuum tank test or space). For our contamination sensitive instruments, we pre-bake boards that have been conformal coated with Arathane in special thermal-vacuum ovens. I don’t want to give a recipe for these bakes, but just wanted to bring it to your attention that while Arathane 5750 works for most NASA TML and CVCM requirements, we go the extra mile as well.

Oh, and since PMPedia is a radiation-type website, I should add that we have flown (or are flying) Arathane into just about every radiation environment. If you have a specific environment (or radiation requirement), please reply back.