Electronics Forum | Tue May 12 06:44:16 EDT 2009 | jhk71
We do a conformal coating for a customer with copper-nickel-gold pads on his board. The pads are masked prior to coating with a standard gel, containing ammonia. After thousands of boards, being processed like this, now the gold pads seem to be less
Electronics Forum | Tue May 12 22:54:46 EDT 2009 | davef
Did the board fabricator forget to apply the nickel undercoat?
Electronics Forum | Mon May 18 08:34:08 EDT 2009 | davef
It's happened perviously. If that happens, there is a widespread solderabily issue, not just on selected pads.
Electronics Forum | Tue Nov 08 17:06:26 EST 2005 | Erik
A while ago I tried using rubber boots for masking but couldn't get them to work because the coating we use (Humiseal 1B73) is so thin it leaches under the rubber. If you can get them to work with your application more power to ya.
Electronics Forum | Tue Nov 15 14:31:59 EST 2005 | Samir Nagheenanajar
Back in the days when I was in charge of a Paintline Dip conformal coater, I had the same issue with a non-hermetically sealed Potentiometer. We tried to use rubber boots, but the capillary/wicking action of our silicone-based heat cured coating was
Electronics Forum | Fri May 15 19:08:25 EDT 2009 | jlawson
Ammonia based masks can create solderability issues after they are removed. You can get non-ammonia based latex mask material but down side is slower cure and cost a little more as they have higher levels of latex etc
Electronics Forum | Wed Oct 26 17:26:32 EDT 2005 | Larry Davis
I have used Kinnarney Rubber Company out of Mantua, NJ in the past with great results. Contact Jim Kinnarney 609-468-1320
Electronics Forum | Wed Nov 09 12:23:34 EST 2005 | SuMoTe
Caplugs Very low tech, and very low cost. you will have to do a bit of work to find a size that will work for you, but the savings are worth it.
Electronics Forum | Mon May 18 02:22:34 EDT 2009 | jhk71
Unfortunately I have no information about the metal layers and the processes. I only see the effect. Is it possible or common that the nickel undercoat could have been forgotten?
Electronics Forum | Thu Jan 22 11:12:06 EST 2009 | davef
Conformal coating masking: Electronic equipment manufacturer's use conformal coating processes to protect printed circuit modules from moisture, fumes, rapid temperature changes and other environmental conditions. Typically, pressure sensitive tapes
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