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 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 | 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 | Wed Aug 16 05:13:41 EDT 2000 | Charles S
Are you running high volume. If yes then what you propose may be relevant. If however you run low volume - lots of changeovers then your wastage/transfer will be equal if not greater than the amount put on the boards. Enclosed systems like DEK Proflo
Electronics Forum | Tue Jul 27 22:30:19 EDT 2004 | KEN
Sr. Tech, when you say you have never had a problem, what exactly does that mean? How do you know you have never had a problem directly associated with your solder process? Do you actively measure your defect levels? How do you maintain traceabili
Electronics Forum | Thu Oct 02 01:47:57 EDT 2008 | myleb
I'm new to SMT. Now, i'm making program for SPI machine to inscpect for solder paste of SP60-MU. I think this is a very good printer but some times, my program shows only 50-60% of volume transfer; and the average height is very high: nearly 200 pct.
Electronics Forum | Wed Jul 28 07:59:50 EDT 2004 | cyber_wolf
Ken, With all due respect: Surface mount is surface mount. Whether you are placing 0201's, or PLCC84's the basic concept is the same. So I would surely hope that for the most part my process is transferable. I guess I was too broad when I said "we n
Electronics Forum | Fri Feb 15 12:29:35 EST 2013 | mikesewell
What foil thickness? Type 3 or 4 paste? Have you checked your area ratio(s)? You could overprint or drop your foil thickness by one mil to improve the ratio and paste transfer. As always you can search the fine SMTnet archives for more info.
Electronics Forum | Fri Aug 20 09:40:56 EDT 2010 | namruht
kpm, We were afraid of that, so we have tried several variations with paste usage. New paste, transfered paste from another line, and a new tube from another date code. I think the problem is profile, board design or humidity. I just have to starti
Electronics Forum | Fri Jun 07 15:16:25 EDT 2002 | gdstanton
Ben, Get a copy of IPC 7525 and review it. This will help you understand the relationship of aperture geometry to paste transfer. Good Luck, Greg
