Electronics Forum | Wed Aug 23 08:05:50 EDT 2000 | Eugene Smelik
Dr. Lee: I have read that fillet lifting can be exacerbated by certain types of Pb-free solder. Can you explain which alloys cause this and why? Thanks! Gene Smelik Cookson Performance Solutions
Electronics Forum | Wed Aug 23 15:10:24 EDT 2000 | Dr. Ning-Cheng Lee
Fillet lifting is a phenomenon mostly observed at wave soldering. It is caused by mismatch in thermal expansion coefficient (TCE) between solder and parts, and aggravated by the pasty range of solder alloys. Upon cooling, the mismatch in TCE will cau
Electronics Forum | Thu Sep 30 11:30:46 EDT 2010 | babe7362000
Take a few parts from the reel and look close at > the parts to make sure the bottom surface of the > leads is below the bottom surface of the body. Yes I did that and they are below the body. I found the problem I think. The solder mask is abo
Electronics Forum | Thu Jul 02 16:01:57 EDT 2009 | ewchong
thanks kpm. agree the cause of those pads lifting. all of them were no connects so they cannot be the cause of the electrical failure. when the bga was removed, all the solder balls on the pcb turned into conical shape due to the separation, except
Electronics Forum | Tue Jul 07 08:42:49 EDT 2009 | ewchong
kpm, you are probably right. under magnification those two pads show some exposed copper which means that they were contaminated or had insufficient solder paste before reflow.
Electronics Forum | Thu Jul 02 13:10:22 EDT 2009 | kpm135
On first glance it looks like those particular pads were not attached to any traces. If I had to guess I would say that your rework profile got hot enough to melt away the glue holding the pads to the board and they came away with your part when you
Electronics Forum | Tue Jul 07 05:55:34 EDT 2009 | kpm135
I agree with your assessment of the two pins with irregular solder. The head-in-pillow or broken joint are both probable events for your defect. At this point in the process it will probably be difficult to pinpoint the exact cause. If it was a broke
Electronics Forum | Mon Aug 09 04:15:33 EDT 1999 | Jacqueline Coia
I am having cleaning problems when processing PCB's which have TAIYO solder mask on them. After processing, hand soldering and cleaning, a sticky residue is remains, resulting in a cosmetically poor finish with tide marks etc. Other soldermasks do no
Electronics Forum | Fri Nov 09 16:58:30 EST 2001 | davef
Go for it!!! You were unspecific, but adding mask to a completed board could cause: * Increased paste thickness, if you have double thickness of solder mask. * Wrinkled and lifted solder mask under the component, if the solderability protection of
Electronics Forum | Wed Jan 05 14:45:14 EST 2000 | Hoyt Moore
Does anybody know how to remove solder mask from pads that were masked over.
