Electronics Forum | Fri Feb 13 09:46:51 EST 2004 | roertner
You might want to check int using a BGA underfill material prior to coating.
Electronics Forum | Fri Feb 13 09:17:11 EST 2004 | Kris
we are worried about the coating not being able to cover underneath the BGA. If the coat is excessive then it would cause CTE issues. Also if anybody has data on 85/85, 1000 hrs after conformal coating of BGA, would appreciate if you guys can share
Electronics Forum | Thu Feb 12 16:57:52 EST 2004 | blnorman
Why can't you conformally coat the BGA? We do on some of our lines with no adverse affects.
Electronics Forum | Thu Feb 12 14:26:22 EST 2004 | Kris
Hi all, We have a PCB without any BGAs on it which goes into harsh environment.We therefore conformal coat it. After assembly the PCBs are expected to withstand "85degc/85%RH for 1000 hours" We now want to add a BGA to the PCB. Does any one have
Electronics Forum | Fri Feb 13 14:50:57 EST 2004 | blnorman
Underfills could improve reliability. If you pick materials right, you could co-cure and underfill and coating.
Electronics Forum | Wed Mar 27 18:23:01 EST 2002 | kmorris
Does anyone have experience doing conformal coating over Plastic BGA in High-Rel PCB assembly? Is underfill necessary to avoid problems with entrapped air, etc? Our application is a 17x17mm BGA, 256 I/O. We are assembling with a water soluable pas
Electronics Forum | Mon Apr 01 13:00:27 EST 2002 | BTaylor
We had a problem with conformal coating getting under an IC and with Temp. and vibration would cause cracking of the solder bump, underfill solved the problem.
Electronics Forum | Wed Mar 27 21:20:30 EST 2002 | davef
There is two major BGA coating camps. * Camp #1: "We require the coating to be under low stand-off devices but with no filleting. So we apply a thinned dip coat first, and then top-off with a proper spray coat" * Camp #2: "We want no coating under th
Electronics Forum | Tue Apr 02 22:52:38 EST 2002 | davef
Tks BT Can't be many places tougher than automotive, 'cept maybe oil field, down pipe. We use Dexter Hysol flow underfills for both 1 thou and 3 thou gaps, but they wouldn't come close to filling under a BGA. Most BGA are sitting about 16+ thou fr
Electronics Forum | Tue Apr 02 11:21:46 EST 2002 | BTaylor
davef I assume this question is for my reply and me. We used a dexter\hysol underfill and a Camalot 5700 to dispense.Single line technique next to a small IC with 14 bumps around the perimeter.The conformal coating was applied with a small brush aro
