Electronic assembly having an indium wetting layer on a thermally conductive body

Abstract

Embodiments include electronic packages and methods for forming electronic packages. One method includes providing a die and a thermal interface material on the die. A metal body is adapted to fit over the die. A wetting layer of a material comprising indium is formed on the metal body. The thermal interface material on the die is brought into contact with the wetting layer of material comprising indium. The thermal interface material is heated to form a bond between the thermal interface material and the wetting layer so that the thermal interface material is coupled to the metal body, and to form a bond between the thermal interface material and the die so that the thermal interface material is coupled to the die.

1 . A method of forming an electronic assembly, comprising:
 forming a wetting layer comprising indium on a thermally conductive body;   positioning a thermal interface material against a surface of the wetting layer;   positioning a die having an integrated circuit formed therein against the thermal interface material;   heating the thermal interface material so that is melts;   allowing the thermal interface material to cool so that is solidifies and forms a thermal and structural couple between the die and the thermally conductive body.   
     
     
         2 . A method as in  claim 1 , wherein the wetting layer consists of indium. 
     
     
         3 . A method as in  claim 1 , wherein the thermal interface material consists of indium. 
     
     
         4 . A method as in  claim 1 , wherein the thermal interface material comprises indium. 
     
     
         5 . A method as in  claim 1 , wherein the thermal interface material comprises indium and tin. 
     
     
         6 . A method as in  claim 1 , wherein the thermal interface material comprises tin. 
     
     
         7 . A method as in  claim 1 , wherein the thermally conductive body comprises a heat spreader including a copper body having a nickel layer thereon, and the wetting layer is formed on the nickel layer so that at least part of the nickel layer is between the wetting layer and the copper body. 
     
     
         8 . A method as in  claim 7 , further comprising coupling the die and the heat spreader to a package substrate. 
     
     
         9 . A method as in  claim 1 , wherein the thermally conductive body comprises a heat sink including fins. 
     
     
         10 . A method as in  claim 4 , further comprising forming the electronic assembly to include no gold between the thermal interface material and the thermally conductive body. 
     
     
         11 . A method as in  claim 1 , wherein an additional layer of indium is positioned between the die and the thermal interface material. 
     
     
         12 . A method as in  claim 1 , wherein the wetting layer is formed to a thickness of no greater than 1 micron. 
     
     
         13 . A method as in  claim 1 , wherein the thermal interface material comprises an indium solder preform. 
     
     
         14 . A method for forming an electronic package comprising:
 providing a die;   providing a thermal interface material on the die;   providing a metal body adapted to fit over the die;   forming a wetting layer of a material comprising indium on the metal body;   bringing the thermal interface material on the die into contact with the wetting layer of material comprising indium; and   heating the thermal interface material to form a bond between the thermal interface material and the wetting layer so that the thermal interface material is coupled to the metal body, and to form a bond between the thermal interface material and the die so that the thermal interface material is coupled to the die.   
     
     
         15 . A method for forming an electronic package as in  claim 14 , further comprising:
 coupling the die to a substrate; and   coupling the metal body to the substrate.   
     
     
         16 . A method for forming an electronic package as in  claim 15 , further comprising forming the body from a material comprising copper and forming a layer comprising nickel on the body prior to forming the wetting layer on the body, so that the layer comprising nickel is between the wetting layer and the copper. 
     
     
         17 . A method for forming an electronic package as in  claim 16 , further comprising, prior to providing the thermal interface material on the die, forming a stack including layers comprising titanium, a nickel vanadium alloy, and gold on the die, so that the stack is positioned between the die and the thermal interface material. 
     
     
         18 . A method for forming an electronic package as in  claim 14 , further comprising, prior to providing the thermal interface material on the die, forming an additional layer comprising indium on the die, so that the additional layer comprising indium on the die is positioned between the die and the thermal interface material. 
     
     
         19 . A method for forming an electronic package as in  claim 14 , further comprising forming the layer of material comprising indium using a plating process. 
     
     
         20 . A method for forming an electronic package as in  claim 14  further comprising forming the thermal interface material on the die from a solder preform comprising indium. 
     
     
         21 - 31 . (canceled)