Ag—Au—Pd ternary alloy bonding wire

摘要

An Ag—Au—Pd ternary alloy bonding wire for semiconductor devices made from 4-10 mass % of gold having a purity of 99.999% or higher, 2-5 mass % of palladium having a purity of 99.99% or higher, and remaining mass % of silver (Ag) having a purity of 99.999% or higher; and this wire contains 15-70 mass ppm of oxidizing non-noble metallic elements, and is thermally annealed before being continuously drawn through dies, and is thermally tempered after being continuously drawn through the dies, and this wire is useful for ball bonding in a nitrogen atmosphere; Ag2Al and a Pd rich layer produced in the interface between the Ag—Au—Pd ternary alloy wire and an aluminum pad suppress the corrosion development between the Ag2Al intermetallic compound layer and the wire.

主权项

1. An Ag—Au—Pd ternary alloy bonding wire for semiconductor devices comprising:
an alloy made from a mixture of Ag having an initial purity of 99.99% or higher; Au having an initial purity of 99.999% or higher; Pd having an initial purity of 99.99% or higher; and oxidizing non-noble metallic elements, including at least one of calcium, a rare earth element and lanthanum; the alloy comprising:
4-10 mass % of the Au;2-5 mass % of the Pd;15-70 mass ppm of the oxidizing non-noble metallic elements, including at least one of calcium, a rare earth element and lanthanum; andthe balance being the Ag; wherein the wire is thermally annealed at least once, followed by continuous drawing through dies, followed by thermal tempering, the wire is applicable for ball bonding in a nitrogen atmosphere and the wire has a HAST reliability of 50% or smaller.