Electronics Forum | Mon Jan 22 11:35:16 EST 2001 | kirks
Hey Mike, what do you recommend for PCB cleaning if there was a mis-print during the screen printing process. Currently we are hand cleaning them with a SMT solution but are having problems with solder balls in the via's and joints. What cleaning mat
Electronics Forum | Thu May 17 08:28:14 EDT 2001 | wavemaster
I would have to agree that the leads are probably geting to hot, but there are many factors that could be the root cause. I would suggest doing a experiment with a solder sample and make 2 recipes. One with a relativly cold profile and one with a r
Electronics Forum | Fri Jun 29 14:13:05 EDT 2001 | markhoch
Just a quick thought on solder balls "or beads" caused when using NC paste. I found a spec (12.4.10 in IPC-A-610C) that says solder beads are acceptable if they are entrapped in NC flux residue and can not be dislodged in the normal service environme
Electronics Forum | Tue Jan 04 07:22:12 EST 2000 | Michael Selva
One of the boards has a via designed right in the middle of a pad for a 1206 cap, one side only. This causes the solder paste to run into the via during reflow. We run No-Clean paste. One alternative is to increase the aperture on the stencil for tha
Electronics Forum | Tue Aug 24 10:58:26 EDT 1999 | James Graves
Does anyone have any information on stencil aperture/pad ratios for noclean solder paste. In the past I have experienced severe solder ball problems when using the same size apertures from aqueous products as I do with the No-clean products. Conseq
Electronics Forum | Fri Feb 12 14:06:28 EST 1999 | Craig Lowe
Bill, I would go with the second piece of advice by leaving a little film of solder paste on the screen. This is good advise if you are using a lookup/look down type of vision centering. Like on MPM and newer Fuji. On older Fuji GSP2/3 style printer
Electronics Forum | Mon Jan 11 09:00:17 EST 1999 | Kelvin Chow
Some of my friends ask me if sombody use lead free solder ball on BGA, espically PBGA packages. I wonder if 96.5Sn/3.5Ag (m.p .221 oC) or 58Bi/42Sn (m.p. 138 oC) would be suitable candidates? Do you have any experience on this subject? Kelvin
Electronics Forum | Mon Aug 27 22:48:21 EDT 2001 | dougk
Used an older model of the one you described. Have used Asymtech and Fuji's as well. The Camalot is accurate, reliable, and easy to program. The only things I disliked about it was that is was slower than the fuji's, and if the pressures weren't set
Electronics Forum | Tue Feb 05 09:19:27 EST 2002 | Carol Stirling
Would someone be able to direct me to information on residual BGA stress please? I've been told that mounting the BGA involves residual stress to the solder balls due to different expansion characteristics of the BGA versus the board at the moment of
Electronics Forum | Tue Jun 04 15:58:06 EDT 2002 | Hussman69
Hmmm... I know the Vitronics oven had bigger motors on em', but I don't think they're blowing molten solder balls around. You did say you changed your profile and stencil designs, which helped, but didn't exactly state what ya did. I believe this
