Electronics Forum | Mon Apr 12 22:38:01 EDT 2004 | Ken
Dave is correct. The void is una"void"able when printing over the via. Sorry for the pun. The smaller the via, the smaller the problem.
Electronics Forum | Sat Mar 06 02:54:25 EST 2004 | tommy
1)Solder paste selection 2)Reflow profile.Focus on soaking and TAL. 3)Moisture control for BGA. 4)Maybe the BGA solder ball already with void. 5)PCB design.Any via on bga land? 6)Solder masking type. 7)Solder paste volume apply on land. 8)IPC class 3
Electronics Forum | Wed Oct 07 15:25:02 EDT 1998 | Joe P.
Hi Everybody | | Is anyone aware of the possible causes that may lead to voids in the solder bumps after assembly. We assembled some dice on thin substrates and after assembly, void formation in the solder bumps were observed. | We have alread
Electronics Forum | Thu Nov 21 06:36:30 EST 2002 | Ben
I'm doing SMT of lead-free solder BGA on FR4 Ni-Au PCB. The solder paste I'm using is Sn/Ag/Cu and reflow with peak temp at 240C. I found there are voids(1-2) in almost every solder joint(500 micron in dia) under xray. And the void size is violate th
Electronics Forum | Thu Feb 19 12:56:29 EST 1998 | Earl Moon
| I'd like someone gives me a tip for elemating of voids | in the mico BGA solder joint and the method of inspection | of them, very exactly. Voids in excess of 20% by each solder ball volume is cause for rejection. Causes are improperly managed proc
Electronics Forum | Mon Apr 12 08:10:17 EDT 2004 | wgaffubar
We are sometimes, not always, seeing very large voids in the solder joints of BGA's with Via in Pad. Some lots of PCB will have the voids and other lots of boards will not. I feel the via's are outgassing during reflow, due to the PCB not having been
Electronics Forum | Tue Dec 23 01:25:38 EST 1997 | J.H Kim
| I'd like someone gives me a tip for elemating of voids | in the mico BGA solder joint and the method of inspection | of them, very exactly.
Electronics Forum | Sun Mar 07 17:53:39 EST 2004 | Ken
Increasing the metals loading may help. But may cause issues elsewhere. Unsure of your exact process....but may work. Is anyone dispensing solder paste onto BGA pads...how is voiding in comparison???
Electronics Forum | Mon Apr 12 22:22:01 EDT 2004 | davef
Large voids are common in via in pad [seach the fine SMTnet Archives for earlier laments], especially in blind via. Observations on your via out gassing theory: * If the copper plating on your via is GT 1 thou, there will be no outgassing from the
Electronics Forum | Tue Apr 13 13:01:01 EDT 2004 | arcandspark
These voids only appear in the solder connections that have a (via in pad). The pads that do not have (via in pad) do not have any voids. Profile is 60 seconds above 183 C and peak of 218 C. The BGA is an OMAP lead free,I am using standard eutectic s
