Metal foam heat sink

Abstract

Further, a system is provided for dissipating heat from a semiconductor module including a semiconductor die and the unitary heat sink. The heat sink comprising a unitary body having both a porous and non-porous portion is provided. The non-porous portion is attached to the semiconductor die and configured to transfer heat to the porous portion for dissipation into the environment. In addition, a method for manufacturing the heat sink is provided.

1 . A heat sink comprising a unitary body having first and second portions, the first portion being generally non-porous and the second portion being generally porous; 
 whereby the first portion transfers and spreads heat within the heat sink and the second portion substantially dissipates the heat from the heat sink.    
   
   
       2 . The heat sink according to  claim 1 , wherein the first and second portions are made of a metal material.  
   
   
       3 . The heat sink according to  claim 1 , wherein the first and second portions include a copper alloy.  
   
   
       4 . The heat sink according to  claim 1 , wherein the first portion is generally solid.  
   
   
       5 . The heat sink according to  claim 1 , wherein the second portion has a melting temperature that is lower than a melting temperature of the first portion.  
   
   
       6 . A system for dissipating heat comprising: 
 a semiconductor die; and    a unitary heat sink attached to the semiconductor die, the heat sink including a non-porous portion and a porous portion.    
   
   
       7 . The system according to  claim 6 , wherein the semiconductor die is soldered to the non-porous portion of the unitary heat sink.  
   
   
       8 . The system according to  claim 6 , wherein the heat sink is made of a copper alloy.  
   
   
       9 . The system according to  claim 6 , wherein a melting temperature of the porous portion is lower than a melting temperature of the non-porous portion.  
   
   
       10 . The system according to  claim 6 , wherein a gas is forced through the porous portion of the heat sink.  
   
   
       11 . The system according to  claim 6 , wherein a liquid is forced through the porous portion of the heat sink.  
   
   
       12 . The system according to  claim 11 , wherein the fluid is a dielectric fluid.  
   
   
       13 . A method for manufacturing a heat sink comprising the steps of: 
 forming a unitary body having a first portion therein and a second portion;    melting the second portion of the body; and    creating porosity in the second portion of the body.    
   
   
       14 . The method according to  claim 13 , wherein the first portion has a higher melting temperature than the second portion.  
   
   
       15 . The method according to  claim 13 , wherein the porosity is created by forcing a gas through the second portion.  
   
   
       16 . The method according to  claim 13 , wherein the step of creating porosity includes the step of integrating a material into the second portion.  
   
   
       17 . The method according to  claim 16 , further comprising the step of solidifying the second portion with the material integrated therein.  
   
   
       18 . The method according to  claim 17 , further comprising the step of removing the material from the second portion.  
   
   
       19 . The method according to  claim 18 , wherein the material is removed by a chemical interaction.