I would go for wash and bake but I worry that washing will "Wash Crud Into"
the shielded areas and the rinse will not rinse it out.

Are your concerns about no clean flux in a marine environment really
justified or is it hog wash from somewhere? 

Bob K.

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Graham Collins
Sent: Friday, December 01, 2017 10:09 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