Electronics Forum | Thu Sep 30 17:36:17 EDT 2004 | GIO
i have a 0.5 pitch(19x19 pbga array) ..with a pad of 20 mils (thou) , solder mask is same...(20th..)..and an stenCil aperture of rectangular 22 X 22.1 thou...WHICH SHOWS..I AM HAVING AN OVERPRINT..MY PASTE IS A NO-CLEAN.. COMMENTS PLS...
Electronics Forum | Sun Oct 10 15:07:04 EDT 2004 | GIO
sorry..it s 40 mils...pitch,...but stencil aperture is square...ANY COMMENTS.. THANKS RUSS...
Electronics Forum | Thu Sep 30 18:23:00 EDT 2004 | russ
Comment: A 20 mil pad for a .5mm pitch BGA? That seems like an awful large pad for this device. If my math is right the pads will be basically touching each other. .5mm = .020". I would think that you have something else. You cannot have a 22mil
Electronics Forum | Mon Oct 11 15:21:20 EDT 2004 | russ
I have heard of making square apertures for round pads to aid in Xray and possibly allow for better release in some applications. The square aperture in your case would be for Xray inspection and not release. Usually a 20 mil square would be used f
Electronics Forum | Thu Feb 08 08:28:11 EST 2007 | mzaboogie
Good Morning Everyone, We have an application coming up with several BGA's on a RoHS assembly. One is a 25 mil ball on a 40 mil pitch, another is a 15 mil ball on a 40 mil pitch. In the past for leaded assemblies, we have used square apertures for 1
Electronics Forum | Sat Dec 15 06:34:54 EST 2012 | sowmya
Normally paste manufacturer specifies stencil life of a paste is 10 hours. the question is, if i run a continuous manufacturing for 40 hours, we will be adding 250 g of paste for every two hours. The addition of 250 g will be mixed with the paste whi
Electronics Forum | Mon Dec 17 09:38:27 EST 2012 | cyber_wolf
Why scrap paste if there is no degradation of performance? Do your own study to determine this.
Electronics Forum | Mon Dec 17 08:34:58 EST 2012 | emeto
I would scrap it. As you said part of it is going to be old paste. All manufacturers don't recommend mixing old with new paste because you change the rheology of the paste.
Electronics Forum | Tue Jul 19 14:33:17 EDT 2011 | ccouture
Has anyone tried using a product thet when applied to a stencil, it facilitates the release of solder paste from the stencil, including the fine pitch openings. It makes the stencil's surface "fluxophobic". Same principle as Rain-X for windshield. A
Electronics Forum | Wed Jul 20 05:49:45 EDT 2011 | kenneth0
I think you are referring to nano coatings. Try google nano coated stencils
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