Electronics Forum | Thu Feb 24 23:11:51 EST 2011 | kemasta
HI I have this BGA short issue, I took x-ray image, the solder ball having big void. We suspect the pad on BGA was oxidie. Reject percentage quite low, only 5 out of 6000. But after the BGA re-ball, is work fine. Anyone have any idea to trobleshoot
Electronics Forum | Mon Mar 21 17:36:44 EDT 2011 | davef
Kim: You could be correct. We had a batch of BGA that had a weird bridging pattern. Could not figure it out. So, we put the whole batch straight out of the 'box' bug-up on a hot plate and video recorded the balls as we took them through a thermal cy
Electronics Forum | Fri Mar 04 00:46:36 EST 2011 | kemasta
Hi ScottE "Is this ball sitting on a via?" I am not sure is I answered your question correct, the ball is sit on the pad.
Electronics Forum | Thu Mar 03 08:06:36 EST 2011 | scottp
I've seen this with through hole via in pad with soldermask plugging from the opposite side. Baking the boards solved it. Not using such a horrible via in pad method would also have solved it, but that wasn't an option. Is this ball sitting on a v
Electronics Forum | Fri Mar 04 01:08:19 EST 2011 | kemasta
Thanks davef Bridging:- There is no heat sink on the BGA, the heat sink will be fix after relow. I do believe paste had something to do with it, but currently this defect didn't appear so oftenly, so we think that the main root cause is not from the
Electronics Forum | Mon Mar 21 02:54:58 EDT 2011 | kemasta
Hi Dave I agree with the 2nd point (sloppy process management) if the failure rate is higher than 5%. But this is 0.083% case, and only happen once in the blue moon. As I study about the re-flow profile for the last whole week, current parameter se
Electronics Forum | Thu Sep 05 03:23:14 EDT 2002 | manic
Hi, I encountered a problem with pbga. One edge either warp downwards or upwards creating bridging or open. This pbga have fr4 at the bottom (compound molding at the top). The fr4 is bigger than the top compound by 3mm at each edge. Pls help. Than
Electronics Forum | Wed Sep 02 06:50:55 EDT 1998 | Masdi Muhammad
Hi, We are having problem with yield loss due to electrical fail. Further investigation shows that the failure is due to solder bridging under BGA. Has been there any study or experience on how this could occur and what we can do to prevent it. Than
Electronics Forum | Mon Feb 28 23:07:04 EST 2011 | kemasta
It is random. By the way, this board pass thought wave process, (BGA is at the top), will that cause the older short issue?
Electronics Forum | Fri Feb 25 09:30:29 EST 2011 | kahrpr
Was the void on the same pad for the 5 failures or were they random
