LEAD FRAME FOR SEMICONDUCTOR

摘要

PURPOSE:To obtain a lead frame with eminent solderability and resin sealing by forming a surface layer through an Ni-Sn alloy plating or a Co-Sn alloy plating all over a metal substrate. CONSTITUTION:After a substrate 1 of tinned copper is punched into a desired pattern, a lead frame having respectively a semiconductor pellet fixed portion 6, an internal lead terminal 8 and an external lead 10 is made. After this lead frame is given the pretreatment such as degreasing and acid bathing, an Ni-Sn alloy plating 7 is set all over the substrate 1 from pyrophosphoric acid bathing with the electrolytic plating method and then a desired semiconductor lead frame is made by this. In case of making an IC package with this lead frame, an Si pellet 4 is placed on the semiconductor pellet fixed portion 6 through an Ag pace wax material 3 and is distributed to the internal lead terminal 8 with an Al fine line 9 and then all is sealed by a resin 11.