Electronics Forum | Wed Aug 19 19:16:43 EDT 1998 | Steve
How is the aspect ratio of a reliable BGA joint defined? Is it best to have H/W between two limits? What are these?
Electronics Forum | Fri Aug 21 15:03:42 EDT 1998 | Dave F
| How is the aspect ratio of a reliable BGA joint defined? Is it best to have H/W between two limits? What are these? Steve: People on TechNet have spent alot of time talking about BGA pad design. Use the link below. Dave
Electronics Forum | Fri Jul 24 01:28:00 EDT 1998 | Alex Ondi
I also heard of a company considering a patent on aperture design. The aperture was a "chevron" aperture, very similar to the "V" shaped aperture recently touted in SMT magazine, presumably for the purpose of reducing solder balls. Go figure!
Electronics Forum | Mon Sep 24 20:38:27 EDT 2001 | davef
Mike's comments are well taken. Your technique works fine with BGA, but uBGA are less forgiving. Again, let's take about: * Specifics of the problem. * Amount and method of applying flux. * What's holding the uBGA in-place before the solder ball an
Electronics Forum | Wed Oct 17 19:12:32 EDT 2001 | scott
Dave's right! Wash the boards RIGHT AFTER reflow, don't let that residue harden. Then you turn around and cure that stuff during the second reflow by not performing the first wash???? wow.... By the way, are you having any problems with white resi
Electronics Forum | Mon Dec 03 21:48:40 EST 2001 | davef
How do yall monitor the concentration of yer saponifier? [NOTE: This is a BIG chance for NC flux-types to make smart remarks in retribution for remarks made about removing solder balls in an aqueous cleaner.]
Electronics Forum | Mon Jan 28 20:06:52 EST 2002 | davef
Sounds like an interesting project. In Euroland and Japan, there are political moves with no scientific basis afoot to exclude lead from electronic products. There is a HUGE body of knowledge on the topic. For instance, Electrochemical Publication
Electronics Forum | Mon Apr 22 18:45:07 EDT 2002 | Steve Townsend
Chances are your profile is fine. There is probably too much paste on the descrete pads. Consider reducing the aperture size of the stencil. Good luck.
Electronics Forum | Mon Jul 15 17:35:42 EDT 2002 | davef
Micro BGA � (�BGA�). A Tessera brand name for a fine [0.5 mm and 0.75 mm solder ball] pitch BGA.
Electronics Forum | Tue Jul 27 10:22:09 EDT 2004 | Chris C
By looking at the solder balls they have not joined with the other particles that are alongside them. suggesting that they did'nt reflow. But they could very well be as you suggested, reflowed and ejacta from the process. We have been experiencing
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