Electronics Forum | Sat Mar 27 08:15:02 EST 2004 | davef
Via in pad is a designer's dream and an assembler's nightmare. Search the fine SMTnet Archives for previous discussions to get started. VIP, via-in-pad, or whatever tend to promote voiding within the via and certainly partially starved solder conne
Electronics Forum | Tue Sep 25 14:08:59 EDT 2001 | davef
Oooo, the solder on the pad and PGA ball is flowing during reflow down the via to the secondary side? Why didn�t you say so?? ;-) Why would you expect that gravity and capillary action wouldn�t force solder to flow down the solder plated via to the
Electronics Forum | Mon Jan 24 08:11:00 EST 2000 | Dave F
Jeff: Whoa bud. I'm sorry. Leave the pads as they are. The calculation was intended to increase the aperture for the pad with the via to compensate for the paste starving caused by the via. Sorry for not being clear. Dave F
Electronics Forum | Mon Oct 20 15:24:52 EDT 2008 | davef
During reflow soldering, sometimes via fill with solder leaving the solder connection starved. Questions are: * Specifically, what is the problem you see? * Do the defective pads show that solder has melted in a uniform fashion? * How do the tempera
Electronics Forum | Mon Feb 21 08:33:53 EST 2000 | Tony Di Mauro
Kurt, When I was working in a captive manufacturing house we had been to migrate toward tenting all vias under the BGA to eliminate not only shorts but insufficient (Starved) joints. Tony
Electronics Forum | Mon Feb 21 08:33:53 EST 2000 | Tony Di Mauro
Kurt, When I was working in a captive manufacturing house we had been to migrate toward tenting all vias under the BGA to eliminate not only shorts but insufficient (Starved) joints. Tony
Electronics Forum | Thu Feb 22 20:53:44 EST 2001 | davef
You're not sposed to pull the mask from the BGA when reworking it!!!! ;-) Well, if you insist. You can be as fancy as you want. Basically, all you need to do form a dam to prevent the solder from flowing from the pad to the via and starving the
Electronics Forum | Mon Sep 20 13:04:25 EDT 2004 | davef
The Intel BGA Developer�s Guide [ http://developer.intel.com/design/packtech/ch_14.pdf ] says: 14.8.3.3 Plated Through Hole (PTH) Isolation Regardless of the technique used for the mounting pads shape or definition, isolation of the plated through h
Electronics Forum | Thu Nov 22 12:56:12 EST 2001 | tony_sauve
Thanks for the comments & suggestions. Here's some info garnered from a telecon w/the PCB Fab house: -the blind via's extend from layer 2-17...this was a revelation. The info from our customer was that the via's only extended down 2 layers. Did I men
Electronics Forum | Fri Dec 18 10:18:55 EST 1998 | Dave F
| I have been developing a BGA Process and are having problems with a 310 IO PBGA reflowing. I am achieving good wetting exept 2 to 5 balls on the outer perimeter I have a good profile my air flow is set per mfg spec, the strange thing is that it doe
