Method for fabricating a semiconductor device

Abstract

A semiconductor device that improves the heat cycle resistance and power cycle resistance of a power module. An electrode member in which copper posts are formed in a plurality of perforations cut in a support made of a ceramic material is soldered onto a side of an IGBT where an emitter electrode is formed. By soldering the copper posts onto the electrode, heat generated in the IGBT is transferred to the electrode member and is radiated. In addition, even if a material of which the IGBT is made and copper differ in thermal expansivity, stress on a soldered interface is reduced and distortion is reduced. This suppresses the appearance of a crack. As a result, the heat cycle resistance and power cycle resistance of a power module can be improved.

1 . A method for fabricating a semiconductor device having a semiconductor element with an electrode on a surface and a electrode member having a plurality of individual copper or aluminum posts connected to the electrode, comprising:
 molding ceramic powder into a molding having a plurality of perforations;   burning the molding to form an insulating ceramic member with the plurality of perforations that pierce through principal planes of the insulating ceramic member;   forming the plurality of individual copper or aluminum posts in the plurality of perforations; and   connecting each of the plurality of individual copper or aluminum posts to the electrode of the semiconductor element electrically and thermally.   
     
     
         2 . The method for fabricating a semiconductor device according to  claim 1 , wherein connecting each of the plurality of individual copper or aluminum posts to the electrode of the semiconductor element electrically and thermally by a solder layer at an interface between the electrode and the individual copper or aluminum posts. 
     
     
         3 . The method for fabricating a semiconductor device according to  claim 1 , wherein forming the plurality of individual copper or aluminum posts in the plurality of perforations includes impregnating the insulating ceramic member with molten copper or molten aluminum. 
     
     
         4 . The method for fabricating a semiconductor device according to  claim 3 , further comprising:
 removing the copper or aluminum formed on the principal planes of the insulating ceramic member after impregnating the insulating ceramic member with molten copper or molten aluminum.