We all hoped for the best but, as usual, compromises exist with any material
selection. Too many uneducated/inexperienced "young" gun designers are
getting carried away with Thermount.

Most of the designs I work with need not have negative CTE's for anything.
Certainly don't need it for leaded devices or BGA's for that matter and hole
wall expansion can be accounted for by specifiec plating thickness and
adequate ductility.

As for the moisture, at .5%, there's no way to use this material with OSP's.
As for the prebaking, you're right on here. With OSP's, as one example, it's
gone when recommended prebake cycles of about 3 hours are done. This is true
notwithstanding the core and preg bake cycles before relamination.

Sure would be nice to have the ideal mateerial but, as you say, study what
works best for your application.

Earl

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