Have you considered conformal coat the module, then hand solder with OA & wash? Regards, Ed Popielarski Engineering Manager 970 NE 21st Ct. Oak Harbor, Wa. 98277 Ph: 360-675-1322 Fx: 206-624-0695 Cl: 360-544-2289 "Nearly all men can stand adversity, but if you want to test a man's character, give him power." Abraham Lincoln -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Graham Collins Sent: Friday, December 01, 2017 9:09 AM To: [log in to unmask] Subject: [TN] board wash / non-washable modules - the dilemma Hello Technet! Wondering what other people are doing with this dilemma. We have had several customers design in pre-built RF modules on their boards. I totally get why, it is a pre-built, FCC approved, easy solution - the fastest way to get a good Wi-Fi or bluetooth solution. Where things go off the rails for me are where this is used in a high humidity application (e.g. a marine setting). We strongly prefer to wash boards, we can build no-clean if needed but I'd prefer not to for an on the water use. But the part a customer has designed in specifically says not to wash it (it has an EMI shield, so they are properly concerned with water entrapment). So - would you: - build it no-clean? - leave the part off, build and wash as usual, install RF module later using no-clean? - wash it (and maybe bake it to dry it out)? - ???? -- regards, Graham Collins Senior Process Engineer Sunsel Systems (902) 444-7867