Electrode structure and its manufacturing method, and semiconductor module

Abstract

There is a highly reliable semiconductor module having a satisfactory bonding strength in the electrical bonded portion. In the semiconductor module 10, a semiconductor chip 11 is mounted on a circuit board 20. In the circuit board 20, on an insulating ceramic substrate 21 is formed a metal circuit plate 22 on which the semiconductor chip 11 is implemented. The semiconductor chip 11 and metal circuit plate 22 are connected with each other by an aluminum bonding wire 23. In the connected portion between the metal circuit plate 22 and bonding wire 23, a coating layer 24 for excellent conjunction therebetween is mounted. The coating layer 24, as shown in an enlarged diagram, is made up of a nickel (Ni) layer 241, a P-distributed palladium (Pd) layer 242, and an Au layer 243 in increasing order. To the P-distributed Pd layer 242 is added P (phosphorous) and, the P concentration on the Ni layer 241 is higher than that on the Au layer side 243.

Dependencies are inferred from the claim text.