Ed -

When I hear of separation between the foil and a board vendors plating I
immediately look for a problem in his cleaning and activation processes,
including tank scum.  Plating separations are fatal, and generally do their
worst after a board has been operated or thermal cycled for some period of
time.

The laminate separation is another thing: You didn't give any detail as to
when the laminate separation is occuring, ie., at the solder process, or other
event.  This could result from several factors: contaminants; insufficient
resin; improper B-stage storage and handling; inadequate cure; etc.  Is this
classic delamination or something different?

From your description, you've done some microsections.  What do the junctions
of inner layers to barrels look like?  Any abnormally dark lines in this
junction when examined @3-400x?

Hope these thoughts help - Email me direct if I can be of assistance.

Regards - Kelly

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