Electronics Forum | Thu Feb 26 21:35:21 EST 2015 | flyingsnow
Hi, has anyone experienced discoloration of cured non-conductive epoxy? It turned from white to deep red. The parts were returned from customer and we noticed the color change and wondered what could cause epoxy discoloration.Thank you!
Electronics Forum | Wed Aug 17 13:57:27 EDT 2005 | ppwlee
We have encountered what appears to be mask discoloration after wave soldering. The areas of concern coincide with the areas that were exposed selectively by fixtures during wave soldering, dominated by one date code of PCB with a slightly different
Electronics Forum | Wed Aug 17 14:30:58 EDT 2005 | russ
I usually see this with mask that is not fully cured from the PCB shop. This probably agrees with the baking statement that you made.
Electronics Forum | Wed Aug 17 22:41:37 EDT 2005 | davef
Peter are you having fun with solder masks erwat? We saw this years ago with LPI solder masks. It shows occasionally with other masks. We agree with Russ. If nothing [eg, alcohol, flux thinner, acetonitrile, or water] dissolves the haze, then it
Electronics Forum | Thu Jul 27 07:50:35 EDT 2006 | davef
Send us pix
Electronics Forum | Mon Jul 24 11:35:42 EDT 2006 | Jimk@ics-inc.org
We have experienced a problem with tin leaching or discoloration of lead terminals on random parts on solder side of a paste/paste operation. The profile has been used on previous production runs and there doesn't appear to be any heat damage to othe
Electronics Forum | Mon Aug 29 16:21:20 EDT 2011 | rjlasko
Greetings...I have a customer that has an assembly that is conformal coated with Humiseal 1A33. This assembly has some components (resistors and FET's) that heated up during operation and has discolored the conformal coating around their location.
Electronics Forum | Mon Jul 03 23:11:04 EDT 2000 | Patrick Ng
hi, We are receiving PCBs with gold fingers "discolored". The "discolored" gold fingers can be removed if rub with soft eraser! We are working with suppliers to determine the root cause and eliminate this issue. Pls assist if you have encountered si
Electronics Forum | Tue Aug 30 09:49:24 EDT 2011 | blnorman
Guess the better question is why are the resistors and FETs heating to the degree that they discolored the coating? If the coating is discolored, I'd be concerned with the possibility of cracking as dave mentioned. Cracks defeat the purpose of the
Electronics Forum | Fri Apr 21 09:03:59 EDT 2006 | choppy
I guess the first thing to look at is the temperature. We had to heat more for QFP256 on sample boards and we saw discoloration on some small parts. Just try to sense around when profiling to see what's there.
