A Technology for Bonding Cu Wires with Cu Pads: Structure and Electrical Fatigue Mechanism of Fine Micro-alloyed Cu Wires.

In this study, ternary and quaternary micro-alloyed copper (MAC) wires were formed by adding trace amounts of gold, palladium, and platinum to copper wires and introducing copper substrates to eliminate the influence of intermetallic compounds on the bonding surface. The reliability of the copper wires and copper substrates after wire bonding were investigated. The results show that the addition of platinum had no grain refinement effect, and the resistance was significantly increased compared to the addition of gold and palladium. However, the platinum-added MAC wire exhibited the best electrical fatigue life whether as a pure wire or bonding with the substrate. After bonding of the MAC wires with the copper substrates, they still retained certain mechanical properties and showed extremely good electrical fatigue characteristics. Overall, the Cu321 wire, with the addition of 0.3 wt.% platinum, 0.2 wt.% gold, and 0.1 wt.% palladium, bonding with copper substrate exhibited the best reliability and can be applied in packaging industries. [ABSTRACT FROM AUTHOR]