Electronics Forum | Thu Nov 07 09:23:05 EST 2002 | russ
What would the considerations be in utilizing a type 4 paste as opposed to type 3? We have an assembly that has a large amount of uBGAs (12 mil diam pad)along with 50 mil pitch BGAs assorted fine pitch etc... We are experiencing difficulty in paste
Electronics Forum | Fri Nov 08 17:10:04 EST 2002 | rspoerri
Is that square inscribed or circumscribed with respect to the pad? It sounds like you're saying circumscribed (overprint) given the volume comment. Wanted to confirm though. Kim
Electronics Forum | Fri Nov 08 17:20:52 EST 2002 | davef
You need to get as much paste on the board as you can get. A BIG opening gives: * Better release. * More paste. You may be able to cheat further by rotating the square so that it is on the diagonal.
Electronics Forum | Fri Nov 08 14:48:58 EST 2002 | davef
Yours is (12 thou x12 thou)/(2x(12 thou +12 thou)x5 thou) = 0.60 * Aspect=W/T for electroformed stencils SB GT 1.1 => Yours is 12 thou/5 thou = 2.40 So, we kind of think of what you�re trying do as maybe printing a 16 pitch QFP, which gives you simi
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 | Thu Mar 09 00:45:57 EST 2006 | kent_peterson
Fastek will get it done with 2 machine and 2 shifts. 2 shifts would need to place 50,000cph. One CP643 with both device tables set could get it done. Having it panelized in 50's, you would need to print 50 panels a hour so get a auto cleaner on the p
Electronics Forum | Fri Feb 28 15:27:50 EST 2014 | tombstonesmt
Good afternoon! Looking to see what everyone else in the industry is running for print speeds regarding type 3 solder pastes. Our paste is a type 3 with 11.5% ROL0 flux content. The finest pitch component in our case is .5mm pitch. Our screen print
Electronics Forum | Wed Feb 09 13:41:48 EST 2005 | rkevin
Does anyone know the smallest pitch I can print succesfully with type 3 powder for a BGA ?
Electronics Forum | Mon Mar 03 13:34:39 EST 2014 | markhoch
I'd start with the paste manufacturer's data sheet. You may be surprised how wide their process window is. If that doesn't help... Can you increase the number of PCBs in your panel?
Electronics Forum | Wed Mar 05 17:46:19 EST 2014 | tombstonesmt
Very good suggestion. We have MPM Speedline printers. Typically we stick with the default after providing the board dimensions. Maybe there's some room there for improvement.
