UBM structures for wafer level chip scale packaging

摘要

A wafer level chip scale semiconductor device comprises a semiconductor die, a first under bump metal structure and a second under bump metal structure. The first under bump metal structure having a first enclosure is formed on a corner region or an edge region of the semiconductor die. A second under bump metal structure having a second enclosure is formed on an inner region of the semiconductor die. The first enclosure is greater than the second enclosure.