Electronics Forum | Tue Jun 07 12:07:30 EDT 2016 | wlsmt
Sorry davef. I was not being clear. PCBAs came out cold soldered after being reflowed the first time with ALPHA WS-820. The flux gel ALPHA WS 609 was supposed to be applied only onto the terminations of caps where ALPHA WS-820 was for a second refl
Electronics Forum | Wed Jun 15 10:38:41 EDT 2016 | laynefelix
Hi everyone..i am new here. I am hardware design engineer and as per my experience PCBAs came out cold soldered after being reflowed the first time with ALPHA WS-820. The flux gel ALPHA WS 609 was supposed to be applied only onto the terminations of
Electronics Forum | Tue Jun 07 10:24:59 EDT 2016 | davef
wlsmt: You’ve got to help us out here: * Why did you apply solder paste to capacitors prior to water washing the PCBA [where the caps were attached?]? * Did you reflow the Alpha WS-609? * How is the Alpha WS-820 involved in this? * Talk about the
Electronics Forum | Fri Apr 16 10:49:55 EDT 2010 | davef
Your picture is not very useful in conveying the stains. Could the stains be a delamination of the board?
Electronics Forum | Wed Sep 26 12:16:44 EDT 2012 | bwjm
Hi Guys,recently i am facing an issue. Refer to the attached photo. This PCB is high RF speed, gold immersion single layer. After reflow, my solder seems to have black stains on it. I tried with SAC305 paste water soluble and no-clean, both results a
Electronics Forum | Thu Apr 15 14:09:48 EDT 2010 | richardli
We found stains on the boards come out of reflow oven. The board itself color changed to yellowish from white . We understand discolor soldermask due to high temperature. This can be acceptable by our customer not the stains. The stains look like wa
Electronics Forum | Fri Apr 16 11:51:26 EDT 2010 | shawnvike
Looks like a simple variance in the solder mask discoloring. Shawn
Electronics Forum | Fri Apr 16 12:17:51 EDT 2010 | richardli
We have asked the supplier use whiter soldermask taking more heat. We also asked the board supplier to double coat board with soldermask. All these tries failed. We are wondering if the stains are flux contamination.
Electronics Forum | Fri Apr 16 13:22:48 EDT 2010 | stepheniii
Have you tried running a few bare boards through the oven? If there is no flux on them and you still get the "stains" then I think you can eliminate the flux as the cuprit. And I've been told that white is the second most difficult solder mask colou
Electronics Forum | Fri Apr 16 23:33:41 EDT 2010 | isd_jwendell
If you are trying for a nice reflective surface you will get a white with better spectral reflection if you paint with an appropriate formula after the board is soldered.
