Electronics Forum | Tue Dec 31 11:48:36 EST 2019 | emeto
Hello experts, I have a 50mmx50mm LGA on a PCBA. I Would like to decrease voiding in these joints and I wanted to hear about your techniques to decrease voiding. Stencil is currently 5mil. SAC305. ENIG finish.
Electronics Forum | Mon Sep 17 14:45:57 EDT 2012 | kkay
We are experiencing voiding on one of our lead-free assemblies on every part. The voiding only occurs underneath the parts and not in the solder fillet (see pic). We have tried baking, curing, washing, multiple pastes and everything else we can think
Electronics Forum | Thu Jun 22 17:47:05 EDT 2006 | davef
First, we expect voiding in imm silver to be similar to ENIG. We expect more voiding in OSP than other common solderability protection. Second, choosing a solder paste, which does not contain resins and activators that decompose at higher temperatu
Electronics Forum | Thu Dec 11 11:59:23 EST 2008 | joeherz
Update - We've tested a board previously having voiding issues with ENIG versions and the voiding has completely disappeared. No other variables were changed. Looks promising. I have an order of LF HASL boards arriving soon that we plan to split i
Electronics Forum | Fri Feb 13 19:51:07 EST 2009 | joeherz
Update Received cross-section analysis for ENIG plated boards and am happy to report that we have no voiding issues. Intermetalics look great and no copper dissolution. No process parameters were changed, only the PCB plating. For now, we are onl
Electronics Forum | Tue May 02 07:46:39 EDT 2006 | Bob R.
Be careful about taking any generic advice and trying to use it to reduce voiding for your particular paste with your particular boards. I've done a few literature searches over the years on causes/cures for BGA voiding in the SnPb world and found a
Electronics Forum | Sat Nov 08 09:10:16 EST 2008 | davef
SN100 was designed for selective soldering and producing low levels of voiding. But thin barrel plating is a common cause of voids in wave and selective soldered connections, as you say. As a result, you checked the plating thickness and it was accep
Electronics Forum | Mon Nov 10 19:45:51 EST 2008 | davef
Joe On the earlier ENIG comment: No, you're not missing anything. ENIG board are less likely to have copper dissolution issues that other solderability protection.
Electronics Forum | Wed Aug 09 09:54:36 EDT 2006 | russ
Use ENIG, plated finish will be too thick and make for a brittle joint. ENIG is self limiting so this condition cannot be present. To ensure that the bond is strong for BGA you must ensure that process is under control. The correct reflow profile w
Electronics Forum | Mon Nov 10 12:29:59 EST 2008 | joeherz
Dave, You've got me worried - All of the boards we've tested to this point are LF HASL. Why do you say "can't be ENIG"? Am I missing something? We have not sectioned soldered boards as yet but plan to shortly. Thanks.
