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Date: | Tue, 15 Jul 97 15:58:03 EST |
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We found that a reduced oxide helped quite a bit. This means that the
inner layer processing is involved in the formation of wedge voids.
I'll bet that lamination cycles can adversely affect the boards too.
Drilling is, of course involved, & wet process brings out the defect.
What problems do you have with reduced oxide?
Matt Byrne
HADCO-Owego
______________________________ Reply Separator _________________________________
Subject: Re: Mechanism of Wedge Void Formation
Author: [log in to unmask] at SMTPLINK-HADCO
Date: 7/15/97 06:37 AM
wedge voids are usually a start of shotty drilling - then seepage of solution
through the voids and that solution then starts attacking oxide layer - which
inturn leads to pinkring. Dm will not make a difference - actually if
drilling is still primary cause - will be the same or worse - since Dm is
thinner coating. A reduced oxide layer can eliviate problem to a certain
degree - but then - reduced oxide brings in a problem of it's own.
regards
Richard Fudalewski
Atotech Canada
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