Electronics Forum | Mon Oct 14 17:59:45 EDT 2002 | russ
When I used the micro-stencils, We purchased the holder from the stencil manufacturer. As far as design we used 5mil stencils for uBGAs,6-7 mil for larger 63/37 balls, and 8 mil for CBGAs. Aperture openings used were slightly smaller than what we wo
Electronics Forum | Wed Sep 30 06:22:23 EDT 2015 | mervin
MPMENG, Thank you so much for taking the time to help. The machine has Y snuggers and flippers. The Pcb is loading in the center all the time. The driver cards look fine there is no obvious faults on them or partially burned. The machine was not in
Electronics Forum | Tue Sep 19 22:15:53 EDT 2000 | Sophia
Hi guys, I have been working in the SMT pick and place process for five years, and now I'm responsible for the solder paste printing process, and one thing that I notice is that the actual process that we have is to poor, actually our main defects a
Electronics Forum | Thu Aug 31 00:07:24 EDT 2000 | Ramon I Garcia C
I Kyung: I'm not sure if we are working with PIHR but we insert some pines in a PCB with a pin inserter machine, after that we run this pcb in a screen printer and put over its solder paste, and then run in a chip shooter and then IC placer and f
Electronics Forum | Tue Jun 27 10:51:42 EDT 2000 | Ioan
Hi Bill, there are a couple of things you should check. Most likely you have too much paste which is squashed at the insertion of the cap. - the paste height, around 7 mils should do. Too much paste will cause shorts under the cap at insertion which
Electronics Forum | Thu Apr 06 00:27:42 EDT 2000 | Dean
I would check their data sheet for the particular product. Thats the range I have for Some Kester products I use... Are you seeing any slumping prior to pick-and-place? Is the bridge in the same place every time? How is your pick-and-place mounting
Electronics Forum | Thu Mar 29 01:22:57 EST 2001 | chinaman
Hello everybody, Two questions came up during an audit (old topics once more): 1. we are not checking the solder paste volume/pad height after printing - others are using an AOI, but is it really necessary? We just do visual inspection randomly. We
Electronics Forum | Tue Dec 14 12:00:34 EST 1999 | Kris Wiederhold
We recently reduced our standard aperture reduction to aid in the reduction of solder on gold defects. Since this reduction in aperture size, we have been experiencing exposed copper at the end of the component pads. The heel and toe joints are per
Electronics Forum | Wed Apr 16 10:45:16 EDT 2003 | Takfire
Recent cross-section analysis for a customer complaint revealed voiding in the solder fillet. In some cases, the remains of outgassing were also observed. During the failure analysis, we also observed failures where the solder fillet wicked on the
Electronics Forum | Fri Sep 10 17:32:59 EDT 2004 | Yngwie
We have recently faced lifted lead problem that happened on our 20 mil pitch QFP. We have infact pushed it back to the incoming quality, but still I have a few questions to bring up : 1) what is the typical coplanarity tolerance that ICs' manufactur
