Electronics Forum | Fri Feb 26 12:01:08 EST 2010 | jdumont
Hey its probably the silicone adhesive
Electronics Forum | Mon Mar 01 07:24:55 EST 2010 | jdumont
No problem just busting, trying to keep the mood light! Cheers
Electronics Forum | Thu Feb 25 07:37:42 EST 2010 | pcbrown
We are using Humiseal 1B31 and polyester dots for masking. We are spraying this in a Binks sprayer mixed at almost 1:1 with 521 thinner. Whe are seeing the coating creating thin halos around the poly dots as if the dots are "rejecting" the coating. T
Electronics Forum | Thu Feb 25 10:30:21 EST 2010 | davef
It sounds like your poly dots are secreting something that affects coating thickness. Is this a function of the adhesive used by poly dot supplier?
Electronics Forum | Fri Feb 26 10:34:03 EST 2010 | kpm135
If I had to guess I'd say they're using a silicone based adhesive.
Electronics Forum | Fri Feb 26 10:42:56 EST 2010 | mleber
Your masking dots are a silicone adhesive. Contact the supplier and tell them you need an acrylic adhesive on the same dots. Normally same cost and lead time.
Electronics Forum | Fri Feb 26 15:41:19 EST 2010 | kpm135
sorry jdumont I didn't see your post until after I posted mine for some reason. If I had seen it first I wouldn't have posted because yours covered it.
Electronics Forum | Mon Mar 01 09:17:56 EST 2010 | duso02
Hey....I think it might be the silicone adhesive! LOL Yeah, that'll do it. We use simple Shercon paper dots. Work like a charm. No evidence of "de-wetting".
Electronics Forum | Thu Feb 25 10:21:49 EST 2010 | jdumont
My guess would be that the adhesive used on the dots contains silicone. We use 1B73 which is also acrylic and it hates silicone. We use silicone RTV to permanently mask around some connectors and unless its fully cured before coating it will cause l
Electronics Forum | Mon Jun 08 13:26:59 EDT 1998 | D.Hammond
I work QA at an OEM in Alberta, Canada. I saw earlier posts on the smtnet regarding PCB haloing criteria. I am currently in a dispute with my PCB vendor over the acceptability of haloing (delamination) around plated through holes and vias on a lot of
