Electronics Forum | Thu Sep 20 11:22:13 EDT 2001 | ert002
Sorry for not getting back sooner.. a virus attacked our network yesterday. The experiment you have outlined is what I had next on my list...just trying to see if anyone had done it before. We will be experimenting with 0.004" and 0.005" thick sten
Electronics Forum | Mon Aug 14 12:08:35 EDT 2006 | cuculi54986@yahoo.com
I agree with using the homeplate design on chips. Some Pb-free solder paste manufacturers recommend 1:1 apertures. This, in my experience, is not a good idea with any of the SAC305 pastes I've tried. I've been using the same stencil design guideli
Electronics Forum | Tue Mar 20 10:27:36 EDT 2007 | davef
Print styles: Print - Most common print mode * A single print stroke forward on first board * A single print stroke reverse on next board Print-Print (Double Print) * Both forward and reverse printing strokes * Helps to ensure complete filling of th
Electronics Forum | Thu Dec 20 08:00:50 EST 2007 | avalancher
Many years ago, we used to double print. The way we did it was with a rubber squeegee set to do a flood stroke, followed by a return cleaning stroke with a metal squeegee. Why?! Well, this was in the days before Laser etch, and because the chem bat
Electronics Forum | Mon May 12 12:58:07 EDT 2014 | emeto
Hello all, I have a diode(gold plated)on some assemblies that gives me a a hard time. The paste is wetting too good and climbs the lead of the component and touches the body which is a defect. I just wonder what if there is a way to heat the board e
Electronics Forum | Thu Jan 02 12:42:49 EST 2020 | slthomas
As far as stencil design for LGA's I was thinking in terms of verifying that you've used the same aperture design criteria that you would normally use for LGA's so you know you didn't introduce some new variable. I've made changes from my norm bas
Electronics Forum | Wed Feb 21 16:14:44 EST 2001 | billschreiber
120 degrees F (49 degrees C.), check the fine-pitch apertures for shape distortion (stainless steel has a very poor memory, once it expands, it doesn�t always contract back to the same position). Check for dings and dents. A good stencil cleaning pr
Electronics Forum | Thu Oct 23 08:13:44 EDT 2003 | davef
The SEMA listing [ http://www.smema.org/smema5.pdf ] says: * D CUT SQUEEGEE: A single diamond edge squeegee which is shaped like an upside down house and made of polyurethane. * FOUR-SIDED DIAMOND EDGE SQUEEGEE: A polyurethane 3/8 x 3/8 four sided, f
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
Electronics Forum | Tue Sep 15 12:11:36 EDT 1998 | Bill Schreiber
Jeff, The use of flux thinner would only add another chemical to the process. Environmentally, that would not be a good idea. My guess is that you would only end up with "thinner jelly" anyway. Alcohol works well on RMA flux. When assemblers switch f
