Method of bonding gold or gold alloy wire to lead tin solder
AssigneeInternational Business Machines Corporation
InventorsH. Ward Conru, Stephen E. Gons, Gordon C. Osborne, Jr., Douglas W. Phelps, Jr., Stephen G. Starr, William C. Ward
Life of this patent
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Abstract
A compression bond is formed between a gold or gold alloy wire and lead/tin solder by forming a head on the wire and forcing the head into a pad of the solder by thermosonic, or thermocompression, or ultrasonic compression bonding techniques. This forms a gold/tin intermetallic compound which in turn forms the bond. The head of the wire is maintained out of contact with any underlying surface, and surrounded by the solder.
Claims12
A method of bonding gold or gold alloy wire to lead/tin solder overlying an underlying surface, comprising the steps of:
- forming said wire with an end portion having a composition of at least 50% gold, maintaining said solder at a temperature below the melting point of the lowest melting eutectic of said solder;
- and compression bonding said end portion of said wire to said solder, said bonding being characterized by said end portion of said wire being forced into said solder a distance sufficient to imbed a substantial portion of said end portion in said solder, but said end portion remaining out of contact with said underlying surface;
- whereby a gold/tin intermetallic compound is formed between at least part of said end portion of said wire and said solder.
Dependencies are inferred from the claim text.