Electronics Forum | Mon Oct 15 12:42:36 EDT 2001 | davef
I hate getting "roped" into math stuff, but here I go again ... Area of aperture = volume of paste / stencil thickness = {[5000 mil^3] / 5 mil} = 1000 mil^2 Side of the square aperture = Sqrt of the area = [1000 mil^2]^1/2 = 32 mil Diameter of ape
Electronics Forum | Sun Feb 28 20:05:54 EST 2010 | aungthura
Dear all There are alot sockets in our products,BIB.These skts are lifted abit after being solderd with wave machine.If the skts become lifted, how much tolerance of the high is acceptable? as example 1mil~5mil,or,1mil~8mil. Pls advise me. Thanks in
Electronics Forum | Tue May 06 21:35:27 EDT 2014 | davef
Indium recommendations: 0201's: * Stencil Opening = 11mil x 16mil rectangle * Foot Print = 12mil x 15mil rectangle * Stencil Thickness = 5mils * Spacing = 9mils Note: The most common stencil being utilized, is the laser cut electropolished, and in so
Electronics Forum | Mon Mar 20 10:54:36 EST 2000 | Glenn Robertson
Jack - The last time I checked IBM was specifying a minimum of 4800 cubic mils of paste for each pad. This is required for acceptable reliability, not just to make the connection. There is no way you are getting that volume with a 5 mil stencil
Electronics Forum | Mon Sep 17 16:03:13 EDT 2001 | jschake
The results from an experiment comparing 27 different combinations of pad dimensions concluded that the pad design with 15 mil pad length, 12 mil pad width, and 9 mil pad separation produced the best assembly yields. A 5 mil thick laser cut stencil
Electronics Forum | Mon Apr 07 13:02:30 EDT 2003 | kmorris
Sorry, I forgot to include the stencil thickness. It is 5 mil. Thanks for the input, everbody. I just checked with our stencil supplier & I thought that Electro-polish was standard with lazer, but I now find out it is not. Our stencil did not get
Electronics Forum | Wed Feb 09 14:23:41 EST 2005 | russ
First off how thick is your stencil going to be? I have printed .5mm pitch with .009" apertures with a 6 mil stencil. A 5 mil would have been better but the 6 worked just fine. Pitch is not necessarily the deciding factor for paste type. it is the
Electronics Forum | Thu May 29 17:19:51 EDT 2008 | dyoungquist
On 0402s we use 20x25 mil pads with a 15 mil gap between the pads on the pcb with ENIG finish, 5 mil stencil with a 1:1 aperture (20x25 mil) and SAC305 lead free solder paste. We very rarely see any tombstoning on 0402s using this setup.
Electronics Forum | Thu Feb 23 18:05:53 EST 2006 | kennyg
What are some general guidelines for the minimum proximity of apertures to a stepdown on a stepped stencil. I have a step from 7 mils to 5 (one mil step each on the top and bottom). How far does the step need to extend beyond the apertures on the
Electronics Forum | Tue Oct 09 20:27:13 EDT 2001 | davef
That�s a 672 BALL BGA, bud!!! It�s a BIG Mutha!!! [I know. I know. For some reason suppliers call balls "pins".] Let�s focus on: * Clarifying the units on your PCB and aluminum plate thickness measurements. * Describing your use of the aluminum pl
