| 摘要 |
PURPOSE:To obtain a thermal expansion coefficient matching material being inexpensive and enabling the direct application of solder and the wide range of matching of a thermal expansion coefficient by a method wherein nickel plates having substantially the same thickness with each other are superposed on the opposite surfaces of an iron-nickel alloy plate respectively. CONSTITUTION:A cladding material 10 is prepared by superposing nickel plates 2 and 2' integrally on the opposite surfaces of an iron-nickel alloy plate 1 respectively. The iron-nickel alloy plate is so constituted that the alloy contains nickel of 35-45wt%. The ratio in thickness between these plates is preferably and particularly within the range of 1/0.5/1-1/5/1. A semiconductor device using this material is made to have a structure in which a silicon chip 3, a solder layer 4, the cladding material 10, a solder layer 4', a copper electrode 7, a solder layer 4'', an alumina insulating layer 8, a solder layer 4''' and a heat sink 9, for instance, are superposed sequentially and integrated with each other by the solder layers. |
