Electronics Forum | Mon May 24 19:37:57 EDT 2010 | jry74
I am new Engineer in conformal coating and I am looking for help with dewetting. What "Tricks of the trade" can I try to reduce or eliminate dewetting? We use a lot of Conap CE 1155 and Humiseal 1B73? Any help would be appreciated!!!
Electronics Forum | Tue May 25 11:37:50 EDT 2010 | davef
Where on the assembly is the dewetting occurring? Factors that influence dewetting usually involve non-ionic contamination such as: * Residues from board manufacture including silicone surfactants from solder resist & HASL rinse contamination * Comp
Electronics Forum | Tue May 25 12:43:00 EDT 2010 | jmedernach
I don't have experience with 1B73. I do have a ton of experience with CE-1155. There are a couple of gotchas with this material. First and foremost is that it HATES silicone residue. If the material is not sticking to parts and they aren't cerami
Electronics Forum | Tue May 25 13:03:35 EDT 2010 | jdumont
Hello, I have no experience with CE-1155 but a ton with 1B73. I would say Justin hit it right on the head. 1B73 does not like to be anywhere near silicone residues. We make sure the boards are handled with gloves after wash, before coat. Unfortunat
Electronics Forum | Thu Dec 06 11:01:19 EST 2001 | Carol Stirling
This SMT process certainly makes a body want to win the $$$ and retire! We have been trying to stabalize the process and keep running into new problems. Any help would be appreciated on this issue. All pads on both sides have the same look - partial
Electronics Forum | Thu Dec 06 19:46:08 EST 2001 | davef
First, we�re assuming that we�re talking hot air solder leveled [HASL] bare boards, eh? Consider using A-600 - Acceptability of Printed Boards as the basis for discussing the bare board problems. It is the bare board analog of A-610 - Acceptability
Electronics Forum | Fri Mar 06 16:17:38 EST 2009 | aj
whats your board finish?
Electronics Forum | Wed Nov 06 03:51:28 EST 2013 | cuperpeter
Hi rob, Thank you very much for your response. Profiling was made exactly on the pad, which showed dewetting, so the values are mentioned for this pad. PCB's is about a week old. It is possible that the surface of pads is already oxidized? I will t
Electronics Forum | Tue Nov 05 09:57:45 EST 2013 | cuperpeter
Hello All, We have a problem with dewetting of solder paste. Problem is most visible on the pads without components (see attached pictures) and occurs randomly, 20% of PCB's. Pcb supplier sent us a cross-section of pads with thickness of Cu, Ni and
Electronics Forum | Tue Nov 05 12:34:54 EST 2013 | rgduval
3-6 months, say, depending on the environment), I might consider a ramp-soak-spike profile to allow sufficient time for the flux to clean any potential contaminants. Cheers, ..rob
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