Electronics Forum | Tue Mar 13 11:13:05 EST 2001 | blair
Hi: We are about to build a batch of highly critical control cards with 5 BGA on them. We just recently had a significantly bad yield at our subcontractor in the San Jose area. We feel it is in the reflow profile that was used but are not 100% sur
Electronics Forum | Thu Jun 07 07:11:41 EDT 2001 | stefwitt
8" ). For calculation of the theta angle, the global fiducials should be placed over the diagonal. Component recognition can be improved if your vision system has different light zones. The steep light should be turned off and the flat light turned
Electronics Forum | Thu Jul 18 15:21:32 EDT 2002 | gdstanton
Steve, Seriously we really do that much. Don't know much about your stuff but our designs typically have as much as five 144 pin QFPs on each CCA. Boards are small and double sided with BGA and uBGA. We build some high reliability space stuff and w
Electronics Forum | Tue Aug 03 16:52:41 EDT 2004 | Dreamsniper
Hi, What contributes to the above? I've got some BGA solder joints with a crystal like flux attached to it like a mini solder ball but do not have a perfect round shape. I had my aqueous cleaner's DI water sent for analysis and everything looks okay
Electronics Forum | Wed Jul 08 00:12:20 EDT 2020 | duchoang
Interesting!. They don't look like voids as usual meanings. The "voids" take the whole size of pads. We built millions of BGA, never seen those before. Look like the pads refused to connect with solder paste and pushed the paste away. Pads contaminat
Electronics Forum | Sun Jan 14 16:35:48 EST 2007 | Austin
I have several boards built at various CM's. We have prototype builds with some JTAG failures on BGA's (1-3 failures with qty 3, 1500 pin BGA's). CM's always claim reflow profiles look good. X-ray does not show bridges and they claim it looks good, b
Electronics Forum | Fri Sep 27 15:30:28 EDT 2002 | russ
greetings all Does anybody have any methods or recomendations for removing/reducing excessive voiding in BGAs that are already on board? Had a bad lot of paste and I believe that we are seeing some opens due to very large voids. Any and all input
Electronics Forum | Thu Mar 04 20:15:51 EST 2004 | davef
Print paste in the holes you don't plan to use and let it dry. That way you don't affect your paste volume in other apertures. The bad news: When you don't want paste to dry and close your apertures, it will do it. When you want paste to dry and
Electronics Forum | Wed Mar 24 15:10:23 EST 2004 | davef
Without a proper picture, I'd reject the parts that you describe based on IPC-A-610, 7.2, which says words to the effect: Defect - Class 1,2,3 - Dirt and particulate matter on assembly, eg, dirt, lint, dross, metallic particles, etc. Absence or pres
Electronics Forum | Mon Feb 18 02:08:06 EST 2008 | lococost
4 days seems a lot. You could be losing flux activation causing poor wetting on the enig. Check your suppliers data sheets for paste life. If it was contamination on the PCB, you'ld expect other components to solder badly as well. Try using a bra
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