With all the recent talk about nailheading, perhaps I can infer that more
shops are starting to see this condition. Several months ago, it occurred to
us that we were seeing an increasing number of nails at x-section. With our
process controls and parameters, nails had always been so infrequent as to
be a non-issue, so we were concerned enough to assign an engineer to study
the problem and run a DOE on our process. Early results have indicated that
HTE copper foils (now the default on all of our laminates) are more prone to
nailheading. We tuned our process parameters to compensate for the change in
foils.

Anyone with similar findings?

Glynn Shaw, President
Proto Engineering Corp.
181 Commercial St.
Sunnyvale, Ca. 94086

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