Electronics Forum | Tue Mar 16 03:16:18 EST 1999 | Scott Davies
| | Can sombody help me with this?? When applying solder paste, what factors determine how high off the PCB the stencil is? We use no fine pitch devices. (mostly 603 and 1206 size components) Any help would be greatly appreciated. As you could probab
Electronics Forum | Wed Dec 16 19:37:19 EST 1998 | Ron Costa
I have a mixed technology board ranging from 50 mil pitch devices to 20mil Qfp's to PBGA-352 at 1.27mm, and 6 Intel uBGA-48 at 30 mil pitch. With all these different package types i'm torn between using a 4 or 5mil thick stencil. The ball dia. is 14
Electronics Forum | Mon Oct 19 17:40:01 EDT 1998 | Eric
Nate, If your stencil vendor has laser-cutting capabilities, they should be able to burn in your fiducial locations. This process involves re-setting the focus of the laser beam to burn the locations 1-3 mils into the surface (as opposed to 1/2 cut
Electronics Forum | Mon Sep 14 10:25:40 EDT 1998 | Wayne Bracy
| Our company currently donesn't have any type of sonic wash to wash boards that have been "miss printed" Wanting to know the best way to go about this. So what we are having to do is spray down the boards with alcohol and wipeing the solder paste
Electronics Forum | Wed Aug 12 16:13:48 EDT 1998 | Alex Ondi
:Try American Plating Systems for Chem Etch Equipment, LPKF (Germany)for Laser cutting systems (A Laser in Oregon is the local distributor for LPKF), Lumonics is another option for Laser cutting systems. Probably should have been more specific. | W
Electronics Forum | Mon Jul 20 13:47:04 EDT 1998 | MMurphy
:On a dense board, a great way to reduce solderballing is to either; print paste 1:1 with pad size using a 5mil foil, reduce aperture openings by 10% of pad size or change aperture shape to "Home Plate" design. If none of these work on their own you
Electronics Forum | Mon Feb 23 22:15:32 EST 1998 | fxb
| Paul, | I've got a third-level ISO Stencil Specification procedure that I did at a past employer that I'll send you...it also deals with the DEK-265 printer (which is what we used) when I talk about frame sizes and image positioning, but you can ed
Electronics Forum | Thu Aug 16 13:46:06 EDT 2001 | Hussman
Hi Pavel, I'll bet you're talking after reflow - so in a nutshell - it is too much solder. Paste goes under the R or C and rests on the mask after placement. During reflow, this excess paste balls up along your part (wow, look Ma, no rocket scienc
Electronics Forum | Thu Aug 23 10:54:41 EDT 2001 | Hussman
I've always asked the board house to send me the Gerber data they used to make the board. I've found that things got moved for reasons unknown to either of us (e-mail gremlins?). 9 times out of 10 I take this Gerber and have my stencil manufacturer
Electronics Forum | Tue Sep 18 18:36:59 EDT 2001 | mparker
... and don't forget proper stencil alignment. Invariably I find most bridging problems for fine pitch parts, etc. is caused by lousy alignment. The alignment must be verified under magnification, using the naked eye is not good enough. Use at least
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