Electronics Forum | Fri Jan 22 16:03:17 EST 2021 | SMTA-64387124
Does anyone see any issues in mixing SMD and NSMD pads within one BGA footprint. We have high current pads which we want to make SMD and the other signal pads to be NSMD
Electronics Forum | Sat May 12 00:04:36 EDT 2001 | zam_bri
The product I'm running currently consist a mix of 20 mil pitch QFP, 50 mil pitch, 0402, BGA and variable size of connectors from small to big, on OSP finished PCB. Running intrusive reflow with a mix packages is a real headache, esplly when you hav
Electronics Forum | Tue Jun 02 21:27:22 EDT 2009 | davef
We've never heard of a situtation where oversized pads caused voiding. Your supplier is correct that the pads on the board should be the same size as the pads on the interposer, but this is to improve reliability issues. Search the fine SMTnet Archi
Electronics Forum | Mon May 25 08:37:28 EDT 2009 | d0min0
Hello, recently we changed supplier of the LF BGA, we did corossection and now have doubts... previous BGA specs : pitch 1mm, ball diameter 0.6mm future BGA specs : pitch 1mm, ball diameter 0.4mm on the crossecrion we found that one of the ball seem
Electronics Forum | Thu Jun 04 20:06:30 EDT 2009 | davef
Since posting the above comment extolling the virtues of NSMD pads and disparaging SMD pads, we've learned that the points apply to all array devices, but in spite of that some designers of fine pitch [eg, 0.4, 0.5mm pitch] array devices choose SMD w
Electronics Forum | Thu Oct 08 15:15:49 EDT 2015 | huske
BGA's are by far much easier to process correctly and inspect. As for LGA's you'll never get 100% of the materiel out from under it during the cleaning process. The voiding issue is magnified with and LGA, the low standoff is the reason for the v
Electronics Forum | Tue Dec 29 22:31:06 EST 1998 | Kelvin Chow
It is still a big concern on using No-clean or aqueous cleaning for CSP assembly. I prefer to use no-clean, however, not all components are suitable to use it. Especially those dirty capacitors or connectors which may cause solderability problem. It
Electronics Forum | Wed Dec 30 17:34:23 EST 1998 | Michael Allen
I'm afraid we don't agree regarding the best test method to use here. My understanding is as follows. The omegameter test measures board-level, ionic contamination (i.e., average for the entire board area and all components); it does not tell you w
Electronics Forum | Fri Sep 19 11:49:54 EDT 2003 | chrissieneale
OK, so is anyone qualifying CGA's yet? Our first batch of CGA qualification is not going too well. We stuck with the teardrop shaped pad but the solder fillet is not as big as expected. What size pads is anyone using, i'm getting conflicting informat
Electronics Forum | Mon Sep 22 02:15:09 EDT 2003 | chrissieneale
We were having void problems with heat transfer down the via's (24 layer boards, shed loads of planes). So we drew the via away from the centre into a teardrop pad. Void's gone!
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