Electronics Forum | Thu May 18 10:20:55 EDT 2006 | slthomas
Russ asks good questions and I think Chunks pretty much nailed it. Aspect ratio (aperture width/stencil thickness) s/b 1.2 minimum (I like 1.5 if I can get it). If your aperture width = lead width (.008"), yours is 1. Tough to get consistent paste r
Electronics Forum | Thu Jun 16 22:14:51 EDT 2005 | davef
16 thou pitch parts: Use a 5 thou laser cut electropolished stencil with 0.008"x0.045" apertures and type 3 solder paste. Bridges Connecting or Partially Connecting Adjacent Leads or Lands * Excessive solder paste * Excessive component placement pre
Electronics Forum | Tue Oct 15 19:27:08 EDT 2013 | swag
See if you can get a sample of Dek's Nano Protek. We use it on all our fine pitch stencils. I'd say it's kind of like car wax for the aperture walls. They operators really like it a bug me every day to order more if we run out.
Electronics Forum | Wed Sep 18 12:31:16 EDT 2002 | dragonslayr
My suggestion is to conduct a Design For Manufacturing (DFM)study on the assembly in question. Pay particular attention to the pad sizes, component lead dimensions and satisfy yourself that those two factors are correct. Given that pads match compone
Electronics Forum | Mon Dec 20 12:50:27 EST 1999 | Wolfgang Busko
Hi Pascal, 0,65mm pitch normally isn�t much of a problem. With 90�m CU I don�t have any experience but would like to know what deviation from nominal value for the pads you get with different PCB-deliveries. In short, for the standard Cu=35�m we se
Electronics Forum | Wed Sep 18 12:35:56 EDT 2002 | stepheno
Fourth - > back to design of PCB. Are there solder dams of > mask between the pads? If yes, that helps. If > not, pay close attention to stencil aperture > width and be sure that the aperture deposits less > paste by 1-2 mils per pad, centered o
Electronics Forum | Wed Sep 18 18:41:17 EDT 2002 | davef
People have made good comments. Additional points are: * Your bridging is probably being caused by one or more of the following: [1] printing too much paste, [2] smearing the paste during placement or subsequent handling, or [3] paste slump during t
Electronics Forum | Tue Jan 08 09:23:18 EST 2013 | lock_2002
This is a question regarding soldermask between pins of fine pitch devices. The majority of our production designs end up with at least 2-3 mils of copper thickness on the external layers due to blind vias, wrap plating requirements, etc. Our curre
Electronics Forum | Mon Aug 23 10:11:55 EDT 2010 | flipit
Hi, I have never been able to find an acceptable dispense process for dispensing small dots of solder paste. I currently have an auger screw automated dispense system and can not accomplish 0.010" dot sizes. In addition, stencil printing is much m
Electronics Forum | Thu Sep 19 11:14:45 EDT 2002 | Jim M.
We had lots of problems with bridging on 15.8mm pitch, QFP17-160 at the start.The board was .032 thick, double sided-six boards to a panel. Here is the problems (not neccessarily in the biggest to little but as i remember them) and solutions that he
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