摘要 |
A composite material includes a structural carrier layer and a relatively thin metal foil layer separated by a release layer. The release layer, that may be an admixture of a metal such as nickel or chromium and a non-metal such as chromium oxide, nickel oxide, chromium phosphate or nickel phosphate, provides a release force for the metal foil layer from the carrier strip that is typically on the order of 0.1 pound per inch to 2 pounds per inch. This provides sufficient adhesion to prevent premature separation of the metal foil layer from the carrier layer, but easy removal of the carrier layer when desired. The metal foil layer may be electrolytically formed copper having a low height profile, on the order of 0.5 micron to 2.7 microns, bond strength enhancing agent coating a side of the metal foil layer. The enhanced surface is subsequently bonded to a dielectric and the carrier layer then removed.
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