Electronics Forum | Wed Sep 30 11:32:45 EDT 2009 | pbarton
What type of conformal coating are you using and are you allowing the coating to migrate under the device in question? If you are allowing the coating unbder the BGA the problem could be CTE of coating is much greater than that of the BGA balls/sold
Electronics Forum | Thu Oct 01 03:03:29 EDT 2009 | cunningham
what we are getting is open circuits not every BGA is failing we use Humiseal 1A33 and currently there is no masking instruction for around the BGA
Electronics Forum | Wed Sep 30 14:17:06 EDT 2009 | davef
What does failure analysis of the BGA indicate? Is this: * ESD damage * Open circuits * Shorting What's the problem?
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 Oct 02 19:04:53 EDT 2006 | DC
We had a issue on the SBGA and found stress built up at the corner of the SBGA after cool down to room temperature. It is confirmed by the warpage analysis. I expected that the stress caused by the heat spreader and the epoxy to the copper frame. O
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
