Substrate for power modules, substrate with heat sink for power modules, and power module

Abstract

The present invention provides a power module substrate including an insulating substrate, a circuit layer which is formed on one surface of the insulating substrate, and a metal layer which is formed on the other surface of the insulating substrate, in which the circuit layer has a first aluminum layer made of aluminum or an aluminum alloy which is bonded to the insulating substrate and a first copper layer made of copper or a copper alloy which is bonded to the first aluminum layer by solid-phase diffusion, the metal layer has a second aluminum layer made of aluminum or an aluminum alloy, and a relationship between a thickness t1 of the circuit layer and a thickness t2 of the second aluminum layer of the metal layer satisfy t1<t2.

Dependencies are inferred from the claim text.