PD ALLOY WIRE FOR BUMP FORMATION, FORMATION OF BUMP AND SEMICONDUCTOR DEVICE USING THE PD ALLOY WIRE

摘要

PURPOSE:To eliminate difficulties involved in use of Au or solder and make it possible to form a bump electrode of a desired height through the mechanical operation of a wire bonder, by employing a Pd alloy wire containing 0.0001-1% of P. CONSTITUTION:A Pd alloy wire W for bumps, 30mum in diameter, containing 0.0001-1% of P, is made using Pd with a purity of 99.95% as raw material. The Pd alloy wire is threaded through a capillary 3. The end of the wire is heated and melted in a reducing atmosphere of Ar-10%H2 gas by arc discharge to form a ball W'. The ball W' is stuck to the upper surface of the Al wiring 2 on a semiconductor chip 1. In this state, lifting up the capillary 3 will cut the wire W in a specified position at the base of the ball W', and will form a bump electrode on the upper surface of the wiring 2 with a neck a1 with a specified height h left on the top of the ball.