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AssigneeGeneral Electric Company
InventorsConstantine A. Neugebauer, Homer H. Glascock, II, Kyung W. Paik, James G. McMullen
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Annealed copper foil (12) is coated with chromium film (16), followed by coating with an appropriate thickness of gold film (14) and is thermocompression bonded to an aluminum metallized substrate (18) on a silicon chip (30) to provide solderable, high current contacts to the chip. The foil is formed into appropriate electrical network-contact patterns (40) and is bonded to the silicon chip only where aluminum metallization exists on the chip. Leaf (wing) portions (46) of the foil extend beyond the boundaries of the silicon chip for subsequent retroflexing over the foil to provide electrical contact at predesignated locations (49). External contacts to the foil are made by penetrating through a ceramic lid positioned directly above the foil area. Thus, direct thermocompression bonding of a principally copper foil to aluminum semiconductor pads can replace current gold detent/bump connections by securing a copper conductor to a silicon chip through an intermetallic AuAl.sub.2 link and an aluminum stratum.
A method for providing substantially inductance-free connection to selected surfaces of a semiconductor chip that bears thereon metal contact padding having a thickness, comprising preparing a foil laminate by coating a conductive foil with at least one metallic conductor capable of forming an intermetallic bond with the chip metal contact padding, and thermocompressively bonding said laminate to the padding by placing the metallic conductor coating in registry with the padding under pressure and at a temperature sufficient to induce a stable intermetallization bond between said metallic conductor and and padding so as to form an intermetallic layer therebetween.
Dependencies are inferred from the claim text.