Influence of Pd content on microstructure and performance of Au-coated Ag alloy wire.

Zhou, Wen-Yan; Pei, Hong-Ying; Luo, Jian-Qiang; Wu, Yong-Jin; Chen, Jia-Lin; Kang, Fei-Fei; Kong, Jian-Wen; Ji, Xing-Qiao; Yang, Guo-Xiang; Yang, An-Heng

Au-coated Ag alloy (ACAA) wires with different Pd content were fabricated in this investigation. Microstructure, mechanical, and bonding performance of the wires were studied to understand the influence of Pd content and help optimization of the ACAA wire. Pd content ranging from 0 to 4 wt% was studied based on the usual level in commercial alloying wires. With increasing Pd content, the ingot presents more obvious dendritic crystals, and the wire shows higher recrystallization temperature with a maximum difference about 300 ℃. On the basis of a comparable elongation, higher annealing temperature is needed and higher tensile strength, Young's modulus, hardness, electrical resistivity, and finer grains are obtained with higher Pd content. Moreover, the grains transform from 〈100〉 texture as drawn to mixed 〈100〉/〈111〉 texture partially after annealing. Less reduction in tensile performance of the heat-affected zone and higher hardness for both free air ball and wire are observed with higher Pd content. Consequently, higher wire pulling force and more pad extrusion are resulted.

DENDRITIC crystals; MICROSTRUCTURE; WIRE; YOUNG'S modulus; ELECTRICAL resistivity; ALLOYS

Journal of Materials Science: Materials in Electronics, 2020, Vol 31, Issue 8, p6241

0957-4522

Academic Journal

10.1007/s10854-020-03178-0