Method of manufacturing heat spreader module

Abstract

A heat spreader module has a pedestal, a heat spreader member joined to the pedestal by a first active hard brazing material, an intermediate layer joined to the heat spreader member by a second active hard brazing material, an insulating board joined to the intermediate layer by a third active hard brazing material, and a circuit board joined to the insulating board by a fourth active hard brazing material. The first through fourth active hard brazing materials are supplied such that the active hard brazing materials have a thickness ranging from 3 to 20 μm when the components of the heat spreader module are joined together under pressure, and contain an active element in an amount ranging from 400 to 1000 μg/cm 2 .

1 . A method of manufacturing a heat spreader module having a heat spreader member, an insulating board, and a metal plate which are joined to a pedestal, comprising the steps of:
 supplying active hard brazing materials each containing an active element, between said pedestal, said heat spreader member, said insulating board, and said metal plate; and   pressing and heating said pedestal, said heat spreader member, said insulating board, and said metal plate to melt said active hard brazing materials, thereby joining said pedestal, said heat spreader member, said insulating board, and said metal plate together;   said active hard brazing materials being supplied such that said active hard brazing materials have a thickness ranging from 3 to 20 μm when said active hard brazing materials are melted, said active element being contained in an amount ranging from 400 to 1000 μg/cm 2 .   
   
   
       2 . A method according to  claim 1 , wherein each of said active hard brazing materials comprises a mixture of said active element and a hard brazing material. 
   
   
       3 . A method according to  claim 1 , wherein said active element comprises Ti. 
   
   
       4 . A method according to  claim 3 , wherein each of said active hard brazing materials comprises a hard brazing material containing 3 to 15 weight % of Ti as the active element or a hard brazing material mixed with 3 to 15 weight % of Ti as the active element. 
   
   
       5 . A method according to  claim 3 , wherein each of said active hard brazing materials comprises an active hard brazing material of Ag—Cu—In—Ti or a mixture of a hard brazing material of Ag—Cu—In and an active element Ti. 
   
   
       6 . A method according to  claim 1 , wherein said heat spreader member is made of a composite material comprising a matrix of Carbon and/or Graphite impregnated with Cu or Cu alloy, or a composite material comprising a matrix of SiC impregnated with Cu or Cu alloy. 
   
   
       7 . A method according to  claim 6 , wherein said hard brazing materials are supplied between said pedestal, said heat spreader member, and said metal plate such that said active hard brazing materials have a thickness ranging from 3 to 20 μm when said active hard brazing materials are melted, and contain said active element in an amount ranging from 400 to 1000 μg/cm 2 , and wherein said active hard brazing material is supplied between said insulating board and said metal plate such that said active hard brazing material has a thickness ranging from 3 to 20 μm when said active hard brazing material is melted, and contains said active element in an amount ranging from 50 to 1000 μg/cm 2 .