Electronics Forum | Mon Oct 14 10:53:28 EDT 2013 | emeto
0.5 if you use electroformed stencil or > 0.8 if you use laser cut. 2. Always use fresh paste 3. Uses the right printer parameters for your paste(for example Alpha likes fast release of the stencil from the board - in DEK this is called separation s
Electronics Forum | Thu Oct 17 21:13:35 EDT 2013 | hegemon
But where does it go, that it needs to be refreshed or replenished on the stencil? Does that "just like wax" product wind up in my solder joints, no matter how small the percentage, and would it then qualify as a contaminant? I heard there are some (
Electronics Forum | Tue Oct 22 09:20:31 EDT 2013 | swag
Yes, car rims (and brass tubas)! You finally helped me get to the bottom of this expensive issue. We fired the culprit. It's the same guy that was using the ultrasonic stencil washer to clean car parts on night shift. It might be snake oil, I don
Electronics Forum | Thu Sep 19 12:08:39 EDT 2002 | ccross
I would like to thank everyone for their time and replies
Electronics Forum | Tue Sep 17 15:03:33 EDT 2002 | ccross
I am working with fine pitch components (15-20 mil) and having soldering problems and would appreciate some opinions. 1) How much of an effect does pad size have on bridging? 2) How much of an effect does solder paste grain size have? What is the re
Electronics Forum | Wed Sep 18 20:55:33 EDT 2002 | scottefiske
I'm with you dave...please provide specifics as to defect condition... Are you getting good wetting to both land and lead? Is there any repeatability to lead/location/device? Do you have paste inspection capabilites to verify deposition? Is it a Pala
Electronics Forum | Wed Sep 18 19:43:12 EDT 2002 | dragonslayr
One more variable I've remembered - pad height with respect to solder mask height. Pads being too low can cause stencil "gasketing" problems that in turn allow more paste to be deposited than needed. Are your fabs HASL or some other media?
Electronics Forum | Fri Sep 20 04:47:29 EDT 2002 | byates
If I were you I would contact your solder paste applications engineer and your stencil applications eng. They are there for this very reason and are very capable
Electronics Forum | Wed Sep 18 18:48:33 EDT 2002 | davef
Fabs can produce a solder mask web between 20 pitch leads, but I've never seen a web for 16 pitch leads. Although, I would like know a supplier that can lay-down a fine web. Minimum solder mask web width is about 0.004 thou. An absolute mininum o
Electronics Forum | Wed Sep 18 06:53:05 EDT 2002 | CH
1) For solder short, pls check the paste height. Too much vol will cause short. For 15 mils use 5 mils thickness stencil if possible. Check profile preheat time to prevent hot slumpof the paste. 2) type 4 powder will be better for 15 mils pit
