| 摘要 |
An under-bump metallurgical structure between the bonding pad of a die or a substrate and a solder bump such that the principle constituent of the solder bump is lead-tin alloy or lead-free alloy. The under-bump metallurgical structure at least includes a metallic layer and a buffer metallic structure. The metallic layer is formed over the bonding pads of the die. Major constituents of the metallic layer include copper, aluminum, nickel, silver or gold. The buffer metallic structure between the metallic layer and the solder bump is capable of reducing the growth of inter-metallic compound due to chemical reaction between the metallic constituents of the metallic layer and tin from the solder bump. |
