Electronics Forum | Wed Sep 16 22:41:51 EDT 2009 | linseeg
PCB finishing is immersion white tin. The brownish is at random location at PCB pad. The issue only affect visual reject but no solderbility functional failure.
Electronics Forum | Thu Nov 11 14:56:22 EST 2010 | davef
We don't know, there are lots of different conformal coating materials and staking materials. Not all combinations behave similarly. Our choice would be to epoxy the component to the board, then conformal coat.
Electronics Forum | Fri Nov 12 04:48:02 EST 2010 | raghu
thanks for your reply sir, for conformal coating Humiseal 1B31, what are the preferable staking materials? please suggest us..
Electronics Forum | Wed Nov 24 13:36:48 EST 2010 | diamondmt
I would suggest Zymet CN-1703 for staking of the components using this coating material we use it very extensively with Humiseal 1B31, if you would like; I would be happy to coat a couple of your samples for your evaluation.
Electronics Forum | Thu Nov 25 05:01:05 EST 2010 | raghu
Thanks for your reply sir... Please tell me, materials you have suggested are reworkable or not...?
Electronics Forum | Tue Nov 30 15:40:09 EST 2010 | diamondmt
Thanks for your reply sir... > > Please tell me, > materials you have suggested are reworkable or > not...? Yes, The material is reworkable, go you Zymet's website you will find all the information located there.
Electronics Forum | Wed Jan 12 10:41:20 EST 2011 | padawanlinuxero
Hello guys ! I have a problem, I am finding some blow holes in the solder join in a resistors pad, can this be because of high humidity in the board? does baking the boards fix the problem? thanks
Electronics Forum | Wed Jan 12 20:18:14 EST 2011 | Jacki
How many % were affected? If a few,it can be caused bcoz of PCB coating. We had encountered it and PCB house replaced for faulty boards. Since then, we do test first if we hve to solder PCBs from this PCB house.
Electronics Forum | Thu Jan 20 08:22:14 EST 2011 | padawanlinuxero
http://www.flickr.com/photos/94427924@N00/5372753378/sizes/m/in/photostream/
Electronics Forum | Fri Jan 21 11:00:56 EST 2011 | xps
Hi, in my experience, the humidity is trapped in the solder paste. Otherwise you can also try to : adjust preheat profile, and /or increase paste viscosity, and /or increase paste metal content (they are the most common causes).
