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
Electronics Forum | Tue Jun 16 15:10:27 EDT 1998 | Bob Willis
Simple x-ray inspection works well have a word with those nice people at Nicolet or Glenbrook. One of them was featured on my x-ray training video for BGA. A procedure for inspection criteria is on my web site if it is of use. | | How do I mechanical
Electronics Forum | Tue Aug 21 21:39:19 EDT 2001 | davef
1) why is No-clean (NC) the preferred process, for BGA mounting by SMT? Probably the same reason NC is the preferred process for mounting non-area array SMT components. 2) why is water-soluble (WS) not a hot choice? There�s not reason not to use
Electronics Forum | Wed Apr 21 20:08:37 EDT 2004 | Dreamsniper
Now the ball starts rolling. I'm lookin' for a new aqeous cleaner. Do I really need chemical cleaners or saponifiers, surfactant etc. for an Aqeous Cleaning Machine in removing OA or Water Soluble flux from under my 1.27mm Pitch BGA down to 1mm Pitch
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