Electronics Forum | Mon Nov 15 12:13:41 EST 1999 | Dave F
Steve: There are guidelines for determining if your aperture has the correct proportions to the foil thickness. Maybe that�s what you�re looking for: 1 Aspect ratio = aperture width/foil thickness Chemically etched SB GT 1.5 Laser cut SB GT 1.2
Electronics Forum | Mon Nov 15 12:09:55 EST 1999 | Dave F
Steve: Continuing with Dan�s thinking, generally, "poor release" (paste hanging-up in the stencil holes) could have three main (or combination of) causes: 1 Equipment: Stencil is too thick. Specifically, your 0.006 should be OK, providing you don�
Electronics Forum | Fri Sep 17 14:30:06 EDT 2004 | russ
You are right, playing with apertures is how to ensure release. Making a stencil thinner or thicker is "playing with apertures" It all relates to aspect and area ratio calculations and what you need to do based upon the numbers you get. Russ
Electronics Forum | Mon Oct 17 11:16:09 EDT 2005 | slthomas
There are a lot of things that might affect your cleaning efficiency. Paste type (no clean or w/s?), cleaning chemistry, aperture aspect ratio (aperture width/stencil thickness), "linty" wipes, etc. Another thing you need to look at is the frequency
Electronics Forum | Wed May 22 12:32:49 EDT 2002 | pwrgroup
which stencil vendor can deliver aspect ratio and area ratio and the statistical information to the user?It's difficult if the pad is modified.
Electronics Forum | Fri May 17 11:10:25 EDT 2002 | wister
Is there any software to design the stencil openings? It may be including automatic modify the aperture,monitoring aspect ratio and area ratio,even let you know the whole vloume of the opening and average ratio?because the stencil design is more impo
Electronics Forum | Wed May 22 12:39:00 EDT 2002 | pwrgroup
and the two ratio is changed if you use different thickness sheet or step-down or step-up.I think real time calculator of the two ratio is very important for tranfer efficience.
Electronics Forum | Wed May 22 12:39:06 EDT 2002 | pwrgroup
Hmmm... Why would you want to to this? I > understand your concern, but why not let your > stencil house manipulate your Gerber and send you > a copy of it before they cut a stencil? Saves > you time and money. Sit down with your stencil > m
Electronics Forum | Sat Jan 04 09:02:17 EST 2003 | davef
Q1. What is the recommended stencil thickness to apply the proper amount of solder for 0603 components? A1. The proper amount of solder is determined by: * Metal content of the solder paste. * Stencil thickness. * Aperture opening. * Other factors,
Electronics Forum | Tue Feb 04 22:28:16 EST 2003 | davef
You could reduce the paste by about 70%. Solder balling and tombstoning will be the issues to fight. The drivers to these don't change with the component size. Use the fine SMTnet Archives for background. Aperture Size and Thickness of Solder Pas
