Electronics Forum | Thu Nov 11 05:30:09 EST 1999 | Wolfgang Busko
For me it sounds like to much paste. If it worked in former runs with the same design and stencil look for changes in your printing process, check the volume and shape of your deposit. Redesigning pads and playing with aperture size allowing for mor
Electronics Forum | Fri Sep 21 14:45:36 EDT 2001 | jschake
I asked several people their opinion of HASL 0201 pads and there was no positive feedback whatsoever. The most common concern was the domed/convex shape of the pad finish that would result in aperture gasketing problems, which you may already have e
Electronics Forum | Wed Nov 10 18:02:54 EST 1999 | John Thorup
Hi Dave Sounds like what we call a "squeeze ball". Usually caused by excess paste squeezed over the mask between the pads of the component when placed. This sometimes escapes the pull of surface tension back to the fillet and escapes to the side, us
Electronics Forum | Wed Apr 10 22:46:04 EDT 2002 | davef
On SMTnet, we've discussed the the frailties of controlling paste height, when volume is a more telling measure. Sometimes if you seperate too quickly, the paste tries to stay attached to the aperture walls. This creates a 'U' shaped deposit with r
Electronics Forum | Mon Sep 21 22:25:05 EDT 2009 | davef
What babies!!!! Sure, give it a try. * Stencil material: metal or plastic, no difference in print, metal is easier to clean, no static problem, available * Stencil thickness: Chips 0.006", SOIC 0.010" [print height equals 1/3 thickness] * For 0603, a
Electronics Forum | Fri Oct 09 06:32:38 EDT 2009 | davef
Here's what is on that post referred to, not sure what you need more than ... "* Stencil material: metal or plastic, no difference in print, metal is easier to clean, no static problem, available * Stencil thickness: Chips 0.006", SOIC 0.010" [print
Electronics Forum | Tue Nov 03 11:46:52 EST 2009 | davef
Search the finee SMTnet Archives for previous posts on the topic. Here's a clip from on of those posts that may get you started. [snip] * Stencil material: metal or plastic, no difference in print, metal is easier to clean, no static problem, availa
Electronics Forum | Mon May 29 02:15:06 EDT 2000 | Dreamsniper
Hi Buddy, We've tried shifting to this process before and from our point of view here are some of the advantage and disadvantages that we discovered. Advantage 1) Cheap Equipment cost as you just need to use your Solder Paste Printer rather than buy
Electronics Forum | Fri Jul 30 17:13:30 EDT 1999 | Dave F
| | | Looking for solder paste specification limits which have reliability data to support them. Currently, we are looking to define the min/max volume necessary to ensure a good joint on CBGA, PBGA, and Micro-BGA's. Any information will be greatly
Electronics Forum | Thu Feb 24 13:28:31 EST 2000 | Dave F
Robert: Ah, opinions are like mothers, everyone has one. Here's mine: 1 Goto the Altera site, get a copy of "AN 114," follow it. Generally, manufacturers are closer to the requirements of their components than others are. 2 Metal showing on the b
