Electronics Forum | Fri Jun 07 10:46:16 EDT 2019 | gregoryyork
The Single Solder ball stuck to the mask may indicate undercured as well. The issue is not so much the mild No Clean flux but the potentially major active HASL flux or Silver Process chemistries causing issues. This has been through flow solder hasnt
Electronics Forum | Fri Jun 07 11:17:14 EDT 2019 | teejsd
Unfortunately for me, I can't say whether those balls were flat on 1 side or not -- sent this board for x-section to see if we had CAF, since my ionics testing wasn't breaking IPC standard. Unhappily my x-sect results were inconclusive. However I d
Electronics Forum | Fri Jun 07 11:19:14 EDT 2019 | gregoryyork
If you have soldered with HASL finish then the worrying chemistry will be more like NON IONIC. They sit there and attract moisture like mad and any chlorides they hold ionize in the moisture attracted and cause electromigration or SIR issues. They ca
Electronics Forum | Thu Apr 22 20:26:39 EDT 1999 | Dave F
| | On various PCB's after building processes,such as reflow, flowsolder and wash. The soldermask on the PCB's have become discoloured, like a 'marble' effect all along the solder side of the board, it is lighter in contrast than normal, although whe
Electronics Forum | Thu Apr 22 18:07:38 EDT 1999 | Tom B.
| On various PCB's after building processes,such as reflow, flowsolder and wash. The soldermask on the PCB's have become discoloured, like a 'marble' effect all along the solder side of the board, it is lighter in contrast than normal, although when
Electronics Forum | Sun Nov 24 20:43:15 EST 2019 | sssamw
If you want to check if solder mask on tented via, better to do cross section to have a clear view. Sometime supplier will not tell you the truth once you ask question for potential quality issue.
Electronics Forum | Fri Nov 22 05:04:07 EST 2019 | SMTA-Matthew
We have some circuit boards where the solder mask seems clear instead of green on top of some of the tented via pads. No gold deposited during the ENiG process and no solder sticks to it but why is it clear and does it have any correlation to the thi
Electronics Forum | Tue Dec 30 11:29:13 EST 2008 | davef
People use green soldermask because people use green soldermask. In the 1950s, the US military selected green, because they liked green better than other colors. So, here we are. We believe the performance of red and blue is comparable with green. T
Electronics Forum | Fri Jul 09 18:36:48 EDT 2010 | rway
We don't use flex pcbs but have the same issue here. Most of our pcbs are HASL finish. I have looked at silver and gold immersion and both look really good under my color camera on my AOI. However, gold is more pricey. There is no additional cost
Electronics Forum | Wed Jul 31 09:20:47 EDT 2002 | larryk
Dave, I'm assuming your unsoldered fids are exposed copper. Do you have any issues with machine vision due to the various color changes the copper goes through as it oxidies? Larry
