Power module substrate

Abstract

The present invention for solving the problem of suppressing the load caused by heat stress applied on an insulation substrate, reducing the manufacturing coat of a power module substrate, and improving productivity provides a power module substrate in which a buffer layer having a surface area one to three times as large as the surface area of the insulation substrate is laminated and bonded between the insulation substrate and the heat sink, wherein the buffer layer is formed using a material having a thermal expansion coefficient between the thermal expansion coefficients of the insulation substrate and the heat sink, the insulation substrate being preferably formed using AlN, Si3N4 or Al2O3, the buffer layer being preferably formed using AlSiC, and a carbon plate or a composite material of AlC, besides the thickness of the buffer layer being preferably 1.5 to 50 times as large as the thickness of the insulation substrate, and the insulation substrate, the buffer layer and the heat sink being preferably laminated via a brazing foil by bonding.

Dependencies are inferred from the claim text.