摘要 |
PURPOSE:To employ a Cu wire in order to eliminate drawbacks of Au wire or solder and to allow formation of uniform bump electrode by mechanical operation of a wire bonder. CONSTITUTION:A thin Cu wire W having purity of 99.9% or above and containing 10-500ppm of P is inserted into a capillary 3 and the tip thereof is thermally fused by arc discharge in the reducing atmosphere of Ar-10% H2 gas thus producing a ball W'. The ball W' is bonded to the upper face of Al wiring 2 in a semiconductor chip 1 and then the capillary 3 is pulled up thus cutting off the wire W at the predetermined root part of the ball W'. Consequently, a bump electrode (a) is formed on the upper face of the wiring 2 while leaving a neck a1 of predetermined height (h). |