Electronics Forum | Fri Sep 28 09:30:07 EDT 2001 | kmorris
Just had a similar phenomenon 2 days ago. May relate to your issue --- or not. Like you, I did a once over looking for mechanical obstruction & couldn't find any. Ran a thermal profile on the offending PCB & all checked out. Looked in end of oven
Electronics Forum | Fri Sep 14 15:23:41 EDT 2001 | davef
I saw your earlier postings on the topic, but am not familiar with Print Pro-E Drawings. Have you tried the common Gerber viewers? Like: * View Mate (View only) - http://www.lavenir.com * CamCAD (View only) - http://www.camcad.com * GC-Prevue (View
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 | Tue Sep 18 15:35:23 EDT 2001 | jschake
A laser cut stainless steel stencil was used exclusively for the evaluation of the complete 0201 assembly process, which addressed printing, placement, and reflow. However, I have also conducted off-line 0201 print tests using a nickel electroformed
Electronics Forum | Tue Sep 18 13:58:01 EDT 2001 | ert002
50%) only over the appertures where there was poor support. Most prints took 2 knead strokes to print OK, but this caused fine pitch leaded devices to almost short. stencil had to be be wiped after kneading. 2 similar devices with exactly the same
Electronics Forum | Tue Sep 18 09:13:13 EDT 2001 | davef
Those of us that appear deaf are only faking. So, you need not yell. Responding to your question, consider: * Contacting the contractors and ask them for the information you desire. Most of the larger contractors are public companies. So, much of
Electronics Forum | Tue Sep 18 15:28:56 EDT 2001 | jschake
This is an interesting dilemma you have been faced with. If both machines are outfitted similarly and running under identical process settings then they should produce nearly the same results, in theory. I do not dispute the observations you are re
Electronics Forum | Thu Sep 27 11:59:14 EDT 2001 | vance
Programming time is going to be your biggest concern with a high mix environment. This includes maintaining programs. Any time a part's appearance changes (color, location of marking, wording, etc) templates need to be modified in some way to produ
Electronics Forum | Tue Sep 25 13:01:48 EDT 2001 | Hussman
If the flux you are applying by brush is alcohol based, use some alcohol on a few failed PCBs and retest. It souldn't take a lot of flux to reflow the balls to a pad that's already covered with solder and flux from the first BGA - unless you are cle
Electronics Forum | Tue Sep 25 14:25:30 EDT 2001 | davef
Points in response are: * Microstencils work fine with paste, although they are a little fussy to use. * Never have used microstencils for flux. * Like Hussman, we dab the uBGA into a puddle of tacky flux and then place it on the board. * On contro
