Electronics Forum | Wed Apr 10 17:05:47 EDT 2019 | davef
I wonder if this discoloration isn't delamination. I'd discuss it with my board fabricator.
Electronics Forum | Fri Jun 07 11:05:35 EDT 2019 | teejsd
Went thru wave solder, yes
Electronics Forum | Fri Jun 07 14:22:51 EDT 2019 | gregoryyork
Would be well worth testing a bare board first
Electronics Forum | Fri Jun 21 02:16:31 EDT 2019 | alanyang
ask your supplier to make micro-section to check whether it is delamination.
Electronics Forum | Fri Jun 07 11:10:08 EDT 2019 | teejsd
We also have a Foresite C3 for spot testing for ionic contamination. I didn't use it at this spot, but used it some other spots around the PCB that showed this color change and with our C3 we were passing IPC standard for ionics. But I was wonderin
Electronics Forum | Fri Jun 07 09:50:13 EDT 2019 | teejsd
Closer pics at angle would seem to support soldermask delam. And I am now wondering if our no clean flux is getting properly inactivated where it is sitting under the mask.
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 11:08:34 EDT 2019 | gregoryyork
OK good if you get really close to the two small solder balls trapped in that greasy waxy residue and carefully turn the balls over you should see that they are flat on the side stuck to the solder resist.
Electronics Forum | Fri Jun 07 11:42:30 EDT 2019 | gregoryyork
Sorry meant to say if the C3 is only testing Ionic then typically this material is Nonyl Phenol which is non ionic so may possibly not see it. Im not familiar with that test, hence we carry out FTIR extraction
Electronics Forum | Fri Jun 07 14:20:40 EDT 2019 | gregoryyork
If you send me the results happy to take a quick look for you. Ask your guys to look out for Minerals Salts, Polyvinyl Acetates etc. Have a great weekend
