Electronics Forum | Tue Nov 06 22:37:35 EST 2012 | davef
Ryan ... "As for bismuth-based lead-free alloys, a lower melting temperature than that of tin-lead is offered together with a cost similar to that of tin [in the area of $3/lb]. Unfortunately, bismuth in soldering alloys tends to create embrittlemen
Electronics Forum | Mon Dec 16 10:23:42 EST 2002 | Grant Petty
Hi, I have checked the archives, but need some advise. We have a 256 pin 1 mm pitch BGA part of our boards, and we have having problems with paste release our of the holes for the BGA. We just cannot seem to get it right, and we have to keep the st
Electronics Forum | Fri Jan 15 09:11:28 EST 1999 | Steve Gregory
| Due to an foul up on my part, a circuit board ECO snuck up on me and I have a solder paste stencil that doesn't quite match the board. Two pads are off by about half a pad each. | | Can the solder paste stencil be modified? If so, what is the tec
Electronics Forum | Thu Oct 26 17:53:32 EDT 2000 | Dave F
John: I�m here. On "what do ya think about that one!..."??? Mutha, that sounds rat�s rump [as Dennis Miller says] ugly. On some boards, we paste a cuppla chips on the break-away panels and then torque the chips from the board after cure. We use the
Electronics Forum | Tue Dec 30 20:23:34 EST 2014 | jeff701
What does "maintain it really good" entail? For reference, this is our maintenance procedure for the FX-D: - At the end of an 8hr shift, the solder paste path is purged start-to-finish using Nordson's ValvePurge. The machine's then powered down and
Electronics Forum | Fri Aug 17 12:03:46 EDT 2001 | davef
We knew they�d make you use those boards, didn�t we? Your boss could be correct, but then again, you might get away with baking. Entek coating thickness is often poorly controlled by fabricators. But if sample boards that you ran are OK, why not g
Electronics Forum | Thu Nov 07 10:59:11 EST 2002 | pjc
IPC-7525 "Stencil Design Guidelines" is a good reference document to have. Here are notes from a Tessera, (a major mBGA mfg.), study- "Application Note Solder Stencil Requirement for mBGA" The stencil aperture is to be square, equal in size to the l
Electronics Forum | Fri Jan 28 12:29:01 EST 2005 | Bob R.
We use the exact same method Chunks outlined for evaluating just about anything we're going to roll out worldwide, whether it's a material or a machine. List your factors (print speed, solder spread, etc), assign each a weight, evaluate each paste a
Electronics Forum | Thu Oct 08 22:32:58 EDT 1998 | Dave F
| | | | I am trying to find out, what possibilities I have, to print solder paste on a board, when the task is to have 120 Microns thickness for the biggest part of the board (85% of the real estate), and then have 250 Microns of thickness on the re
Electronics Forum | Thu Oct 08 03:27:00 EDT 1998 | Thomas Blesinger
| | | I am trying to find out, what possibilities I have, to print solder paste on a board, when the task is to have 120 Microns thickness for the biggest part of the board (85% of the real estate), and then have 250 Microns of thickness on the rema
