Abstract
This study focused on the materials issues and related reliability testing on Cu-core solder joints for power device, low temperature solder joints for flexible substrate and the utilization of Cu-Zn under-bump metallization (UBM) in micro-BGA solder joints. The fabrication of electrodeposited Cu-Zn metallization is also demonstrate. The future prospect and challenge for the material system and the reliability issues in microelectronic packaging are also addressed.