| 摘要 |
PROBLEM TO BE SOLVED: To provide a substrate for power modules that can reduce warpage and can avoid decrease of the coefficient for thermal conductivity regardless of the difference of the coefficients of thermal conductivity between an insulating board and a radiator. SOLUTION: A material 18 having a low coefficient of thermal expansion is laminated on a radiator body 17 of the radiator 16. The radiator body 17 is formed with a material having a high coefficient of thermal conductivity such as pure Al preferably with purity of 99.5% or higher including, for example, pure Al, an Al alloy, pure Cu, or a Cu alloy. The material 18 having a low coefficient of thermal conductivity is made of a material having a lower coefficient of thermal conductivity than that of the radiator body 17, for example an Fe-Ni-based alloy. A thickness A in the lamination direction of the material 18 having a low coefficient of thermal conductivity is formed to be 0.05 times or larger and 0.10 times or smaller than a thickness B in the lamination direction of the radiator body 17. COPYRIGHT: (C)2004,JPO&NCIPI |
