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Wed, 6 Sep 2006 01:59:45 -0400 |
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Hi All,
I am recently shifted into PCB design filed; interesting field off course!!! satisfied being a part of product development.
Now started learning the reason for each task I perform. Hope I can get more suggestions from expertise here :-).
I understand the reason that slodermask is used for better solderability, but I want to know why we provide certain clearance like 0.005" or 0.004" more than pad size, sometimes I see soldermask missing (say on BGA). Any problems you have experienced due to larger or smaller soldermasks?
Is there any specific standards or calculation used for soldermask creation based of padstack,Assembly process say wave soldering or reflow soldering? How IPC calculates this? I have IPC SM782.
Awaiting for your suggestions.
Thanks,
Raja.
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