Electronics Forum | Fri May 17 16:37:28 EDT 2002 | Tom Druan
I was wondering if anyone could direct me towards documentation on shear test methods/apparatus to test the bond integrity of a solder ball to its substrate. Thanks.
Electronics Forum | Fri May 17 16:53:50 EDT 2002 | davef
I recall a couple of papers in the SMTA 'Knowledgebase' that used ball shearing and an element in a study that compared BGA [maybe uBGA] component fabrication methods, er sumpin.
Electronics Forum | Tue Jun 04 22:54:32 EDT 2002 | davef
Solder balls are one of the most popular topics here on SMTnet. Search the fine SMTnet Archives for background. We like to wash solder balls from the board in our cleaner.
Electronics Forum | Tue Dec 31 02:04:19 EST 2019 | sssamw
From the picture, I cannot see clearly solder ball violate electrical clearance or cause a short, maybe it is. What I can see is the solder paste has some misalignment although it doesn't printed in solder mask area, but actual position will reduce
Electronics Forum | Wed Jan 01 22:19:33 EST 2020 | sssamw
Solder ball attached on solder joint without violation minimum electrical clearance is acceptable. If your process parameter including stencil not changed, suggest you check if solder pasted being pushed out after IC placement, also check if solder j
Electronics Forum | Tue Dec 31 02:06:21 EST 2019 | sssamw
Yes, from the picture, it seems the gap between solder pad is very small, easy to have solder ball/solder bridge.
Electronics Forum | Tue Dec 31 01:30:07 EST 2019 | sssamw
Do you have clear pictures show IC soldering and the solder ball? DO you have clear picture show the PCB pad?
Electronics Forum | Tue Dec 31 09:24:22 EST 2019 | SMTA-Davandran
You may try reduction on stencil aperture on the particular IC location. Reduction on width and extend outer length may help to minimise solder ball issue. However, please look into stencil foil thickness to meet AR.
Electronics Forum | Fri Jan 03 11:37:24 EST 2020 | emeto
Sometimes might be internal change with personnel. Issue is actually there, but if no one questions it-it is not an issue. With 7mil stencil there is a good chance to have solder balls. So were they registered or were they fixed/cleaned?
