Hi Steve

Typical pad to mask clearances are 3mil, so that would leave only a 2mil strip of mask. 5mil is more commonly required by most
fabs. With round pads (BGA) the fab may accept it, but most would not countenance a 2mil strip if it's any length.

While it may be useful as a surface tension modifier, it's almost never present in the case of fine pitch parts where the
challenge of bridging is greater.


Best Regards
 
David Greig
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-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Steve Gregory
Sent: 12 February 2007 17:11
To: [log in to unmask]
Subject: [TN] LPI soldermask resolution

Mornin' All!
 
What kind of resolution should a LPI be able to give you? Specifically, LPI's should be able to give you a solder mask dam
between 20-mil pitch leads if you have 8-mils of space between the pads shouldn't it?
 
Thanks!
 
-Steve Gregory-

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