Device mounting board, semiconductor module, and method for fabricating the device mounting board

Abstract

A device mounting board includes a metallic substrate, an oxide film formed such that the surfaces of the metallic form are oxidized, an insulating resin layer disposed on the oxide film facing one main surface of the metallic layer, and a wiring layer disposed on the insulating resin layer. The film thickness of a certain partial region of the oxide film disposed below a first semiconductor device is greater than that of the other regions surrounding the partial region of the oxide film. Conversely, the film thickness of the insulating resin layer underneath a second semiconductor device is less than that of the insulating resin layer underneath the first semiconductor device.

What is claimed is: 
     
       1. A device mounting board comprising:
 a metallic substrate; 
 an oxide film formed such that surfaces of the metallic substrate are oxidized; 
 an insulating resin layer provided on the oxide film that faces one main surface of the metallic substrate; and 
 a wiring layer provided on the insulating resin layer, 
 wherein the thickness of at least part of the oxide film is greater than that of the other parts of the oxide film. 
 
     
     
       2. A device mounting board according to  claim 1 , wherein a plurality of semiconductor devices having different heat generation rates are mounted, and
 wherein the at least part of the oxide film whose thickness is greater than that of the other parts thereof is a predetermined mounting region of semiconductor devices, whose heat generation rate is relatively large, in the plurality of semiconductor devices. 
 
     
     
       3. A device mounting board according to  claim 1 , wherein the insulating resin layer, which is provided above the at least part of the oxide film whose thickness is greater than that of the other parts thereof, has a portion having a thickness less than the thickness of other parts of the insulating resin layer. 
     
     
       4. A device mounting board according to  claim 1 , wherein a surface of the at least part of the oxide film, whose thickness is greater than that of the other parts thereof, is positioned at the same height or level of surfaces of the other regions thereof or is positioned further toward the metallic substrate than the surfaces of the other regions thereof. 
     
     
       5. A device mounting board according to  claim 1 , wherein asperities are formed, on the one main surface of the metallic substrate, in the at least part of the oxide film whose thickness is greater than that of the other parts thereof. 
     
     
       6. A semiconductor module comprising:
 a device mounting board according to  claim 1 ; and 
 a semiconductor device electrically connected to the wiring layer, the semiconductor device being mounted on a main surface of the device mounting board on a side where the wiring layer is formed.