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 | Mon Aug 19 11:36:27 EDT 2019 | bulur
How does no-clean flux residues on a PCB assembly impact the ROSE testing? Does no-clean flux residues on the PCBA dissolve in solution of ROSE tester and increase ionic contaminants level in terms of NaCl per surface area? Is ROSE tester solution (a
Electronics Forum | Fri Jul 23 05:25:20 EDT 2004 | greg york
Got to agree with John on this, get a stencil cleaning wipe something a little more potent than standard IPA and wipe the surface thoroughly, this should produce a green residue of solder resist. If this does happen then ask your PCB vendor to look a
Electronics Forum | Thu Jan 28 15:53:12 EST 1999 | Dave F
| | Hello Netters, | | | | I need some info, Earl or Dave, I have a PCB that exhibits a white layer on solder side. It does not appear to be surface residues (IPA has no effect), but looks like its under solder mask. My first guess is that the LPI
Electronics Forum | Tue Sep 21 11:39:41 EDT 2004 | pabloquintana
Conformal coat a bare board to determine if there > is there is enough surface free energy from your > solder mask to prevent dewetting. Sorry for my ignorance, but what is "enough surface free energy"? How do I determine that? >* Bake a board
Electronics Forum | Mon Oct 23 14:05:08 EDT 2000 | Aokilab
Hi Soza: As Dave F mentioned, there are lot of factors involving the formation of residue, after cleaning. Factors, (such as: solvent's cleaning power, presence of metal oxides, type of soldering flux, etc...). One thing pretty sure, IPC is usually
Electronics Forum | Wed Jul 23 10:44:40 EDT 2003 | ADAM
Guys I was wondering if anybody out there had any suggestions for cleaning populated pcbs that have been contaminated with salty sea water . There is alot of evidence of white residues and salt deposits on the pcb's. I've tried putting them through
Electronics Forum | Tue Jul 29 05:04:20 EDT 2003 | gregoryyork
Dear adam Sounds to me like it may not be Salt water contamination or even flux residue's, as both of these are commonly cleaned semi aqueosly or with IPA. Have you considered it may be Talcum powder used as fillers in solder resist, mineral salts
Electronics Forum | Mon Apr 29 09:54:46 EDT 2002 | davef
MadReindeer If this white residue is salt, * Why do you say is the presence of it 'not dangerous it only looking bad'? Don't salts sometimes go into solution with moisture on the board from humidity in the air and form cathodic plating shorts betw
Electronics Forum | Wed Sep 01 17:34:18 EDT 2010 | kevm
Having solder flow issues on gold pads. Issues started when supplier switched adhesive tape used to cover pads during varnish process. By running SEM/EDX and XPS analysis it has been determined that the new tape leaves behind a thicker organic residu
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