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 | 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
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 | Tue Mar 01 13:48:49 EST 2011 | davef
Kim, Just add a new posting to this thread then.
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 | Wed Mar 09 17:01:10 EST 2011 | davef
We don't think your voiding is related to your bridging. We'd guess: * Voiding is either poor material selection or improper process recipe choice * Bridging is sloppy process management
Electronics Forum | Mon Feb 28 07:36:56 EST 2011 | davef
Kim Here's an approach to posting pictures: * On your posting, clickon 'Edit' * Scrolldown past the 'Quote' 'Preview' 'Post' etc line * Clickon 'Attachments' * Enter your picture location * Select the choice that allows viewing the picture * Close ou
Electronics Forum | Mon Feb 28 23:08:48 EST 2011 | kemasta
Davef I tried to click the "Attachment" button, but it trigger "Post" button, so I can't attach the picture here.
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
