Electronics Forum | Wed Jan 16 11:20:52 EST 2002 | bentzen
Hi... We tend to do a lot of footprint calculating for new SMD components. But what about the amount of solder paste on the solder pads. The amount of solder alloy is of cause determined by the stencil aperture size, stencil thickness and the sold
Electronics Forum | Wed Jan 16 15:22:29 EST 2002 | Terry Burnette
In his book titled "Manufacturing Techniques for Surface Mount Assemblies" author R.J. Klein Wassink describes the relationship between solder land dimensions, component lead coplanarity, board warpage, solder volumes, and solder paste flux wetting b
Electronics Forum | Sat Jun 26 02:32:32 EDT 2010 | prinsisgarcee
how do i calculate false call rate? i got this equation = [over reject / (total solder joints + components) ] * 1000000 and i got a table which shows data like number of solder joints, components on panel, and number of false call, and the false
Electronics Forum | Fri Jul 09 19:20:49 EDT 2010 | rway
This table, is it in a database? And is it indicating the number of component, solder insp. etc based on one board or one panel? It needs to be based on the total number of inspection on your panelized pcb. The equation works, you may just be look
Electronics Forum | Sun Nov 07 10:54:21 EST 1999 | Steve Thomas
We're looking at redesigning our stencils to facilitate better (well, it's pretty much non-existant, so any improvement is a big leap) release from fine pitch apertures. Currently we have perpendicular walled laser cut apertures. We'll be having
Electronics Forum | Steve Thomas |
Sat Nov 13 15:18:11 EST 1999
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 | 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 | 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
