Electronics Forum | Thu Oct 08 08:15:39 EDT 2009 | kpm135
We've used both 1A33 urethane and 1B31 acrylic coating on our SMT assemblies with great success for many many years. This is with components of all shapes and sizes including a 9 ball micro-BGA. We apply the coating in every way imaginable and we hav
Electronics Forum | Thu Oct 01 07:03:55 EDT 2009 | davef
We doubt that Humiseal 1A33 is causing opens in your assemblies. We'd guess the opens occur earlier in the process, but are not hard failures. So, you pass your tests. When applied, the conformal coat flows into the gap in the ball crack and insulate
Electronics Forum | Wed Sep 30 08:21:07 EDT 2009 | cunningham
Hi We have a board at the moment thats passing ICT and passing functional test but its failing test after conformal coating has anyone had any experinces of this? or any idea what may be causing this?
Electronics Forum | Mon Oct 05 04:55:42 EDT 2009 | pengliang
we suggest as below : the first : check the soldering(solder ball and pad) by X-ray ; second: to do dye analyse (note:pls confrm is there have crack )
Electronics Forum | Thu Oct 08 01:07:46 EDT 2009 | tpappano
I have used 1A33 for many years with excellent results on through-hole pcbs in equipment subjected to very hot and very cold environments. Because 1A33 continues to harden with time, I assumed it would simply not be usable on smt boards, cracking t
Electronics Forum | Mon Mar 21 02:41:29 EDT 2011 | kemasta
Hi It's me again. Our products need to pass a chamber test 45c/36hrs after the PCBA completed batch of functional tests and assemble in to case. We found 1 unit was functioning for 24hours in the chamber, but hang after that. We tried to re-boot the
Electronics Forum | Mon Jan 12 02:29:13 EST 2009 | sachu_70
Hi Milan, One cause for such BGA failures could either be a laminate warp (bow or twist) formed during your Reflow or Wave soldering process, or perhaps a warp seen on the BGA component package itself prior to processing on SMT line. IPC guidelines f
Electronics Forum | Mon Mar 21 12:34:58 EDT 2011 | scottp
If there was a ball in cup defect on the original assembly then it could behave like you explained.
Electronics Forum | Mon Mar 21 23:10:13 EDT 2011 | kemasta
Hi Scott Thank you very much.
Electronics Forum | Thu Jan 08 10:56:13 EST 2009 | aj
Hi, Is there any PTH Assembly after reflow, we found cracked joints on some BGAs which was caused by operators ing Oupin connectors which were a tight fit. This caused the PCB to flex hence cracking joints. One way of checking for this during test
.gif)
