Semiconductor module radiator plate fabrication method, radiator plate, and semiconductor module using the same

Abstract

When insulating substrates of different shapes are soldered to a radiator plate, a third concave curve is previously formed on an insulating substrate side of the radiator plate. The third curve is determined by adding a second concave curve which is expected at the time of actually soldering the insulating substrates to the radiator plate to a first concave curve obtained by moving upside down a convex curve which appears at the time of soldering the insulating substrates to a flat radiator plate. A bottom of the third curve is positioned under the large insulating substrate, and a curvature of a portion where the distance between the bottom and a reference point of the radiator plate is longer is made smaller than a curvature of a portion where the distance between the bottom and a reference point of the radiator plate is shorter.

What is claimed is: 
     
         1 . A semiconductor module radiator plate fabrication method comprising:
 soldering a plurality of insulating substrates of different shapes to a flat radiator plate, and forming a convex curve on an insulating substrate side of the radiator plate;   obtaining a first concave curve by reversing the convex curve;   setting a second concave curve on an insulating substrate side of a radiator plate after soldering, a bottom of the second concave curve being positioned under clearance between the plurality of insulating substrates;   adding the first curve and the second curve to calculate a third concave curve on the insulating substrate side; and   forming the third curve on a flat plate to form a radiator plate before soldering.   
     
     
         2 . A semiconductor module radiator plate having, on a side on which a plurality of insulating substrates of different shapes are soldered, a third concave curve obtained by adding a first concave curve obtained by reversing a convex curve formed, by soldering the plurality of insulating substrates of different shapes to a flat radiator plate, on an insulating substrate side of the radiator plate and a second concave curve which is set on an insulating substrate side of a radiator plate after soldering and a bottom of which is positioned under clearance between the plurality of insulating substrates. 
     
     
         3 . The semiconductor module radiator plate according to  claim 2 , wherein:
 a bottom of the third curve is positioned under an insulating substrate which is the largest in area of the plurality of insulating substrates of different shapes; and   a curvature of a portion of the third curve positioned under an insulating substrate which is the smallest in area of the plurality of insulating substrates of different shapes is smaller than a curvature of a portion of the third curve positioned under the insulating substrate which is the largest in area of the plurality of insulating substrates of different shapes.   
     
     
         4 . The semiconductor module radiator plate according to  claim 3 , wherein a material is copper or a copper alloy. 
     
     
         5 . A semiconductor module comprising:
 a plurality of insulating substrates of different shapes; and   a semiconductor module radiator plate having, on a side on which the plurality of insulating substrates of different shapes are soldered, a third concave curve obtained by adding a first concave curve obtained by reversing a convex curve formed, by soldering the plurality of insulating substrates of different shapes to a flat radiator plate, on an insulating substrate side of the radiator plate and a second concave curve which is set on an insulating substrate side of a radiator plate after soldering and a bottom of which is positioned under clearance between the plurality of insulating substrates.   
     
     
         6 . The semiconductor module according to  claim 5 , wherein:
 the curve of the semiconductor module radiator plate is concave on the insulating substrate side; and   a bottom of the concave curve is positioned under clearance between the plurality of insulating substrates.   
     
     
         7 . The semiconductor module according to  claim 6 , wherein a material for insulating plates used as the plurality of insulating substrates is alumina, aluminum nitride, or silicon nitride.