Electronics Forum | Fri Nov 19 22:48:26 EST 1999 | mark
Steve, your comments from your stencil vendor are very interesting. Any decent laser cutter automatically cuts a trapezoidal aperture. This is just the nature of the cutting. We have a bunch of lasers (and chem-etch). You have to polish your laser cu
Electronics Forum | Steve Thomas |
Sat Nov 13 15:18:11 EST 1999
Electronics Forum | Tue Nov 09 17:12:38 EST 1999 | Dave F
Steve: Addressing your points: 1 FINE PITCH APERTURES Electropolishing Laser Cut Stencils: Laser cut should not requiring polishing. Geesh, how much money do you have for stencils? ;-) Oval Shaped Apertures: Pass. What do you expect to gain f
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 | 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 | Sat Nov 13 14:09:45 EST 1999 | se
First, let me say what I always say: a good chem-etched stencil will print fine pitch. Chem-etch brings trap to the side walls because its a physical by-product of the process. Because they are less expensive you can add electropolish and still save
Electronics Forum | Tue Nov 09 19:45:48 EST 1999 | Steve Thomas
1 Money IS an object, and my boss will be thrilled. The stencil manufacturer recommended ovals to facilitate better release. Seems likely to be true, but whether or not it's necessary I don't know. We have perpendicular walls on these (6 mil) ste
Electronics Forum | Fri Feb 15 12:29:35 EST 2013 | mikesewell
What foil thickness? Type 3 or 4 paste? Have you checked your area ratio(s)? You could overprint or drop your foil thickness by one mil to improve the ratio and paste transfer. As always you can search the fine SMTnet archives for more info.
Electronics Forum | Wed Feb 13 09:47:36 EST 2013 | cnotebaert
what type of paste are you using?
Electronics Forum | Mon Feb 18 12:09:17 EST 2013 | pbarton
What type of flux material does your solder paste have? I have seen difficulties when attempting to print small apertures with water washable and rosin types. Do you get a good first print and then have problems or is it the same from the start?
