Materials Characteristics of Ag-Alloy Wires and Their Applications in Advanced Packages

The materials characteristics of annealing-twinned Ag-alloy wires with various Au and Pd contents were evaluated in this paper. The results indicated that both Ag-8Au-3Pd and Ag-15Au-3Pd have higher strength and corrosion resistance than do pure Ag and binary Ag-Pd wires. On the other hand, the pure Ag, Ag-0.5Pd, Ag-3Pd, and Ag-4Pd wires possess the merits of lower material cost, higher electrical conductivity, and higher electromigration durability than do the ternary Ag-Au-Pd wires. However, the breaking load and elongation of pure Ag wire are inferior to those of Ag-0.5Pd, Ag-3Pd, and Ag-4Pd wires. In addition, the corrosion resistances of pure Ag and Ag-0.5Pd wires are far inferior to those of Ag-3Pd and Ag-4Pd wires. Based on these performances, the ternary Ag-8Au-3Pd wire is an ideal substitute for the traditional Au wire due to its high strength, corrosion resistance, and reliability, while the Ag-3Pd and Ag-4Pd are cost-friendly bonding wires for high-frequency integrated circuit devices.