Electronics Forum | Fri May 11 11:52:25 EDT 2001 | jagman
Does anyone know what would cause a PCB to develop white spots all over the board following parts placement and reflow? I need help!!
Electronics Forum | Sat Sep 12 09:49:38 EDT 2015 | davef
If the boards were still "wet" after DI wash, your [I assume] low res flux could be reacting with the moisture on the board and causing the white spots. The preheater in the wave could have more dryification than the preheater on the selective solde
Electronics Forum | Thu Feb 12 12:30:16 EST 2015 | stevezeva
I remembered something from the TechNet a long time ago about heating the board with a heat gun to see if the white spots disappear. I searched the archives and found this from Bill Kenyon: Quick identification of solder mask white spots- if it is t
Electronics Forum | Fri Sep 11 15:27:50 EDT 2015 | u4bga
Hi! We're noticing white spots on 2 PCBAs after the selective soldering & DI Wash processes. ----Facts---- 1) The marking is on all boards, irrespective of date code 2) It only happens on leads that have been selective soldered 3) The pattern of w
Electronics Forum | Sun May 13 21:02:34 EDT 2001 | djarvis
Gary, You're not trying to clean these boards with Iso or other solvents after using no-clean solder paste? That'll do it.
Electronics Forum | Fri Mar 19 05:21:11 EST 1999 | Vinesh Gandhi
Hi Folks, Need help, on white spots/marks which we are getting after wave soldering. This problem has started only once we have shifted to the no clean flux. Prior, to this we have been using aqueous cleanable flux without problems. If brushed vi
Electronics Forum | Fri Jun 17 11:08:37 EDT 2005 | Stefan
The inner light ring creates a direct light to the fiducial. If you deal with a very shiny fiducial (or board) the light will reflect into the lense, create white spots in the camera CCD chip and make the fiducial shape un-readable. Use the outer li
Electronics Forum | Sat Nov 08 09:42:22 EST 2003 | ethercom
Hi: I have seen this problem before. It is caused by improper curing of solder mask by the fab manufacturer. When you run the board thru' wave solder, and then wash the board, you see the problem of white residue. However, when you apply heat, you c
Electronics Forum | Mon May 14 19:16:49 EDT 2001 | jagman
Dave: Actually, I'm located in the South Bay (Santa Clara)! Good guess. Now, for more in-depth information: So far, the distribution has been limited to one board out of 10 assembled, so far from one lot. The components assembled are exclusively
Electronics Forum | Thu May 14 22:45:46 EDT 2009 | davef
You're correct. It's a peculiar looking defect. With measling, we expect to see discrete white spots or crosses just below the surface of the base material. We don't see that here. We do see a similar condition at almost every PTH in the picture, a