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Date: | 07 Oct 96 16:51:27 -0500 |
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Why do you prefer glossy masks,
We specify matte or semi glossy to reduce solderballs!!!
______________________________ Reply Separator _________________________________
Subject: Matt vs. Glossy soldermask
Author: [log in to unmask] at internet
Date: 10/7/96 2:43 PM
We got in a batch of boards with a bad soldermask. When we were
compareing the bad boards to a known good board from a previous run the
most obvious difference was that the bad boards had a matt mask where the
known good boards had a glossy mask. The obvious cause was some kind of
contamination. The upshot is that it has been legislated now that all
future boards will LPI glossy. Internal politics aside, what kind of
specification, if any, do you guys put on your documentation to specify
soldermask?
Do you use a note on the drawing, a material callout table, an entry
in your PCB spec, or what?
How specific are you?
Is there any real performance difference between matt and glossy LPI?
What do you fab and/or assembly shops prefer -- why?
In the past we have allowed the board shop to do their thing and only
specified LPI and standard thickness etc... These were primarily SMT
with only passives (ie. caps, resistors, diodes) on the backside.
Thanks,
[log in to unmask]
Don Walker
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