to Kevin, Groovy et al

I guess we kinda got off track on the nailhead problem and voids that may be
created because of.nailheads. 

I think that most of us think of wedge-voids as voids appearing along the
oxide line and hole wall interface.  It seems that wedge-voids can be present
regardless of nailheading or no nailheading, regardless of  the type of
direct plate or even with electroless copper; though with electroless copper
they are usually filled with electroless and electrolytic copper in the
finished board.  Some people do not accept these wedge like appearances even
when filled with electroless copper and electrolytic copper and scrap the
boards, IPC-RB-276 accepts this appearance, but other specs are silent on the
subject which allows some to make up new rejectable defects and scrap the
product.

Phil Hinton
Hinton "PWB" Engineering 
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