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 | 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 | 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 | Fri May 11 15:43:41 EDT 2001 | davef
More information would be helpful. For instance: * Talk about the distribution of the problem, including a single lot or from various lots and over components and component types on the board * Tell us about the board (ie, thickness, type, solder ma
Electronics Forum | Mon May 14 22:24:11 EDT 2001 | davef
The time over liquidous of the profile seems short. But then again, who knows? Based on what you told us, I'm guessing at a board fabrication problem, either measling or delamination. Probably the former, rather than the latter. [Now, we remember
Electronics Forum | Fri Jul 20 17:38:06 EDT 2018 | mikedcmt
We have some MLCC capacitors that show some discoloration, or spots. Does anyone know if this will affect reliability? Caps test good - and assemblies function perfectly.
Electronics Forum | Mon Jul 23 09:55:26 EDT 2018 | mgerrior
have not seen this issue personally, often identify cracks on MLCC parts but never dark spots. May be worthwhile to replace as a precaution if at all possible.
Electronics Forum | Mon Jul 23 10:56:38 EDT 2018 | dleeper
I've never seen this before and I would be suspicious. Have you tried to dust it off with a brush or Q-tip, it might just be some sort of process contamination. Have you looked at the reel to see if the parts are coming in with these spots from the
Electronics Forum | Mon Jul 23 11:02:56 EDT 2018 | mikedcmt
Thanks for your reply - parts in tape have similar markings - gets worse after reflow. ~20% have this issue. Units pass test no problem. Occurrence is random.
Electronics Forum | Fri May 12 19:42:05 EDT 2023 | emeto
Have you tried cleaning these spots with anything?
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