Electronics Forum | Sat Jan 23 17:00:44 EST 1999 | Earl Moon
| | Hi Everyone, | | We plan to build, for reliability/experimental/research purpose some CSPs (namely Tessera microBGA 46-I/O 0/75mm pitch and TI 64 I/O 0/8 mm pitch). the various factors that we plan to evaluate are the reliability and assembly con
Electronics Forum | Mon Sep 14 16:14:23 EDT 1998 | Jeff Sanchez
| Dear Larry, | I developed the ultrasonic cleaning process for Smart Sonic. It has developed into the most widely used stencil and misprinted PCB cleaning process worldwide. With that in mind, I offer some words of caution. "IT'S NOT THE ULTRASON
Electronics Forum | Fri Aug 20 03:19:22 EDT 1999 | PeterB
| | | | | | One of the DFM suggestions I've seen is to remove the solder mask web, i.e. the mask between pads on 20-mil QFP devices. The rational is that if the mask is thicker than the pad the mask can prevent the stencil from making intimate conta
Electronics Forum | Mon May 21 17:34:22 EDT 2001 | davef
Continuing the line of Michael's, the previous poster, comments ... The more Krispy Kremes, the better. Yeth!!! The more beer, the better. Yeth!!! The more epoxy, the better. Uh, I don think so!!! We look at this from a papa bear, mama bear, bab
Electronics Forum | Wed Jun 09 17:53:06 EDT 1999 | Tom B.
| I am interested in seeing how some of you quote smt work. Currently we quote off a bom without component packages known then look in data books to find out what type of component they are. This job will be mine soon but i really believe there is a
Electronics Forum | Sun Apr 25 11:44:14 EDT 1999 | Earl Moon
| | We are just starting to manufacture a PCB with a .039" fine-line PBGA. We are currently seeing voids, mainly in the center, that are as much as 45%. We also intermittently see the corner balls of the PBGA smaller than the center balls. We are usi
Electronics Forum | Fri Jul 16 06:22:31 EDT 1999 | Wayne Sanita
Mark, I had the same peoblem. For my stencils i use a 15% reduction for the width of fine pitch leads only, as Earl said follow the 1:1.5 standard. We consider pitches of 32mil and under. We also clean the stencil every other board to ensure no caki
Electronics Forum | Mon Feb 19 13:04:17 EST 2001 | billschreiber
The ultrasonic frequency used in today�s stencil cleaners is usually a 40 kHz �sweep� frequency (also used on semiconductors and other sensitive cleaning applications). This frequency is not low enough to cause stencil damage (the lower the frequen
Electronics Forum | Mon Aug 16 16:54:57 EDT 1999 | Scott Cook
| One of the DFM suggestions I've seen is to remove the solder mask web, i.e. the mask between pads on 20-mil QFP devices. The rational is that if the mask is thicker than the pad the mask can prevent the stencil from making intimate contact with th
Electronics Forum | Wed Dec 13 20:22:37 EST 2000 | Dave F
George We use a 0.030" dot. Here's a link for aperture sizes for adhesive printing from Alpha. http://www.alphametals.com/products/techarticles/soldrpstncl/guidelines.html Here's a link for aperture sizes for adhesive printing from Heraeus. http:/
