Electronics Forum | Fri Oct 03 07:49:18 EDT 2003 | mk
Mask Musings. Soldermask (SM) and its functions have changed and evolved over the years. As an ex-solder mask applicator, I can remember screening Colonial High Gloss Epoxy soldermask on boards back in the early 80's, ending up with a thickness that
Electronics Forum | Tue Jun 01 05:17:16 EDT 2004 | Alistair MacAdam
I am currently looking at the volume of paste being deposited on a PWB 2.4mm thick with a 0.25mm tolerance. I am looking for information on PWB variation and a MPM AP25 series printer, and can the volume of paste be controlled on varing PWB thickness
Electronics Forum | Mon May 07 16:07:05 EDT 2012 | davef
Start with targets based on the stencil thickness (for height) and stencil thickness times the aperture size (for volume). * Set reasonable upper and lower control limits (+ 25% and –25 % of the targets, for example). * Next, check the printer set-u
Electronics Forum | Wed Jun 07 22:33:50 EDT 2006 | Bolos
first: what is your problem after reflow? second: a good rule of thumb is a tolerance of 1 mil. for example..if you got 5 thou stencil thickness then your range of thickness is 6-/+1 thou.. then you just improve after you get your height data and ana
Electronics Forum | Fri May 26 09:49:34 EDT 2006 | pjc
This question cannot really be answered definitively here. There are unknowns such as your board design and solder land finish. I suggest you conduct a DoE (Design of Experiments) to determine paste print deposition X-Y-Theta tolerance for your appli
Electronics Forum | Thu May 25 18:41:15 EDT 2006 | russ
How accurate is your placement machine? if it is accurate I would eval up to 25% off pad. the problem I might think you will have is errant paste or balls causing shorts if it doesn't coalesce completely. Bottom line is, if the board is good at th
Electronics Forum | Fri May 26 08:16:14 EDT 2006 | Chunks
This could be what we call a "non-problem". If your print is off slightly, yet after reflow there is no solder related defects, it should be considered OK. Move your inspector from the printer to right after the oven. This would enable them to ins
Electronics Forum | Tue May 30 16:02:04 EDT 2006 | slthomas
Do a dirty DoE...print ten boards with the worst error you think you can accept, build them up, and count print related defects. At the same time, print ten spot-on and proceed the same. If you don't have any more defects on the off-print batch show
Electronics Forum | Fri Oct 03 05:27:24 EDT 2003 | kanwal324
the puspose of solder mask is to prevent exposure of cu tracks to atmosphere. the lesser thickness can effect the performance of board but it only depends on its application. if you are making telecom board then its not good to use the board.
Electronics Forum | Wed Jan 25 18:31:05 EST 2012 | kahrpr
A few years ago a lot of stencils were 6 mill and 7 mills and a lot of people still use them. these days with such a hi mix on the boards 5 mill seems to be a good compromise. if the 6 mills is working for you that's fine. One thing to note as you go
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