Electronics Forum | Fri Sep 30 10:07:44 EDT 2005 | davef
Alternate explanations are: * Your reflow profile needs to be tweeked. * Bumps under a die look different than elsewhere on the package. Severe creases may indicate a problem, but creases of only a 0.001 to 0.002" deep should not pose any difficulti
Electronics Forum | Wed Apr 27 10:47:26 EDT 2005 | HOSS
A 1:1 pad to ball diameter will cause the balls to collapse more giving you less post solder component standoff. Depending on the application of this product and required reliability, you may want to stay with the padstack being used. You may try c
Electronics Forum | Thu Jul 05 10:45:01 EDT 2001 | dougie
Steven, There is a load of info on this if you check through the archives. Quick pointer though are: Solder balls are caused by paste creeping under the component at placement. The part is placed and the paste is squashed under the component, when t
Electronics Forum | Mon Feb 14 12:05:24 EST 2000 | Dave F
Masdi: Are you sure you have your washer set-up correctly? We never have problems with solder balls. Ta. Dave F
Electronics Forum | Fri Feb 11 08:51:45 EST 2000 | HMAL
Dear Masdi, Perhaps you should check again your screen print process. Small amounts of solder paste under stencil can cause your problems. This paste is from previous printed pcb. When printing next pcb this paste attachs to places that it doesn't
Electronics Forum | Thu Nov 29 01:37:30 EST 2018 | cannizzaro
I think silicone mask is ok, This is so that after soldering, you can use these holes to fit other components later. This peelable layer is needed, unless you want to solder each component manually--From ALLPCB
Electronics Forum | Fri Jul 10 14:40:12 EDT 1998 | Bob Willis
Yes this can be a killer. Its caused by glues with a high water content or fast curing of glues. When you get solder going through the glue it is litterally sucked in during solder wave contact. If you have never seen it you would never believe it bu
Electronics Forum | Tue Nov 20 12:31:12 EST 2007 | kelz
In my past experience, having via's under or attached to SMD lands produces risk. Solder will not consistently wick the same if it is being drawn into a via. This has also caused issues from solder wetting through the via to the other side causing a
Electronics Forum | Wed Jun 24 23:52:41 EDT 1998 | Phillip Hunter
| Has anyone seen a problem with solder under chip components, in-between the glue and the component or in-between the mask and the component? We seen both. | What could be causing this? This has only been detected on one of our products. All the re
Electronics Forum | Tue Nov 13 09:36:18 EST 2007 | rgduval
From a manufacturing standpoint, this isn't very nice. Vias will tend to wick solder away from the pad, resulting in insuficient solder joints, which require touch-up. The amount of times any solder joint is reheated should be minimized, as extra h
