| 摘要 |
PURPOSE:To make an IC package with an eminent reliability by setting an Ni alloy layer including more than one of P, B, Fe and Co on a metal substrate surface and providing a copper or a copper alloy layer, and a silver layer in order at least on a semiconductor element fixed portion and an internal lead terminal on it. CONSTITUTION:An IC lead frame consists of an internal lead frame 6, an external lead frame 7 and a semiconductor element fixed portion 5 fitted up with an Si chip. This lead frame is set a 0.5mu thick 8% P-Ni alloy layer 2 all over the surface of a metal substrate 1 with the electroplating after the pretreatment using such as degreasing and acid bathing of the metal substrate 1 of 42 alloy, for instance. After a 0.1 thick copper layer 3 is set as an intermediate layer with the electroplating using a copper cyanide bathing all over the metal substrate 1 provided with the 8% P-Ni alloy layer 2, a 4 thick silver layer 4 is set with the electroplating on both the semiconductor element fixed portion 5 of the lead frame and the terminal 8 of the internal lead 6. Thus, a copper layer of the part of which is not covered with the silver layer 4 is made through being dissolved and eliminated anodically in the cyanide bath. |
