Electronics Forum | Sat Nov 08 09:42:22 EST 2003 | ethercom
Hi: I have seen this problem before. It is caused by improper curing of solder mask by the fab manufacturer. When you run the board thru' wave solder, and then wash the board, you see the problem of white residue. However, when you apply heat, you c
Electronics Forum | Fri Aug 05 11:32:29 EDT 2005 | saragorcos
Hi Sandy, Here are some suggestions for an optimum cleaning process for cleaning under BGAs if they are assembled to the board to add to the great tips Shean already listed: - Use a good saponifier w/ DI water - an effective saponifier will be able
Electronics Forum | Mon Oct 05 16:05:40 EDT 2015 | cyber_wolf
Washing no-clean solder residue out from under BGA's might present a challenge.
Electronics Forum | Tue Apr 19 16:20:05 EDT 2016 | davef
Don't blame it on the poor paste thickness requirement [although I might go on to argue that it's could be a contributor to the issue]. Most likely you're the problem. About 70% of the time solder on gold fingers is caused by poor cleaning of screen
Electronics Forum | Tue Mar 30 20:04:19 EST 2004 | Ken
If speed is truly an issue, migrate to no-clean. However, this is not always an option. Why bake after 1st smt pass? Because you are probably not drying completely under the BGA components, and/or you are pushing water into the parts/boards/ vias
Electronics Forum | Thu Jan 09 18:19:51 EST 2003 | babe
The Ersa system is fine however there are thermocoupling problems and the service from Ersa has been very poor of late. The Metcal won't handle larger boards and the heating is inconsistent.Especially with BGA components. We see this via inspection
Electronics Forum | Tue May 21 17:16:51 EDT 2002 | davef
Larry, Yes, no matter how much you�d like to avoid using NC, you probably will have to start using the stuff, if the design [sales, in your case] types have their way. We can clean WS under 1mm and 1.25mm pitch BGA. For 0.8mm pitch BGA, we use NC.
Electronics Forum | Tue Jun 01 07:18:15 EDT 2004 | johnwnz
Abraham, it kinda depends on your BGA ball size, device height. The probem is that very few machines will manage to get cleanign fluid under a BGA and you certainly will struggle to get it dry. You would need to look at various supponofiers as well.
Electronics Forum | Wed Mar 20 13:54:56 EST 2002 | Aaron C
I am starting to use BGAs more and more in our process, which is using water soluble paste. Taking to the Paste Rep, he had pointed out that if you add Surfactant Packs to your inline water wash, that it would help get the water underneath the BGA pa
Electronics Forum | Thu Sep 07 11:35:45 EDT 2017 | slthomas
That is a good point, and was something that we discussed yesterday in our process eng. meeting. I don't have an answer right now as to the current cleanliness but I know they were washing (U/S) the stencil repeatedly during the previous run and in
