Multi-layer polymer-solder hybrid thermal interface material for integrated heat spreader and method of making same

Abstract

A process of making a multi-layer thermal interface material is depicted. The multi-layer thermal interface material is attached between an integrated heat spreader and a die. Processing of the multi-layer thermal interface material includes stamping or other pressure processing.

1 . A process of forming a heat transfer composite, comprising: 
 laminating a solder preform to a matrix to form a heat transfer subsystem; and    bonding the matrix to the solder preform, wherein the matrix is formed by a process selected from: 
 co-extruding and singulating a plurality of first heat transfer structures and a second heat transfer structure; and  
 mixing, casting, curing, and singulating a plurality of first heat transfer structures and a second heat transfer structure.  
   
   
   
       2 . The process according to  claim 1 , wherein the matrix includes a polymer, and wherein bonding includes a process selected from cold stamping and pressing under a heat load.  
   
   
       3 . The process according to  claim 1 , wherein the matrix includes a polymer, and wherein bonding achieves the heat transfer composite with a transition between the matrix and the solder preform, wherein the transition is selected from an interface and a concentration gradient.  
   
   
       4 . The process according to  claim 1 , wherein bonding includes supplying the solder preform material, selected from a base solder alloyed with an active element material, indium, tin, tin-indium, silver, tin-silver, tin-silver-indium, lead, tin-lead, lead-free solder, and combinations thereof.  
   
   
       5 . The process according to  claim 1 , wherein bonding is carried out in a pressure range from about 200 pounds force to about 400 pounds force.  
   
   
       6 . A method comprising: 
 disposing a heat transfer subsystem between a die and a heat spreader; and    bonding the heat transfer subsystem to the die and the heat spreader to form a heat transfer composite from the heat transfer subsystem, wherein the heat transfer composite includes: 
 a plurality of first heat transfer structures disposed in a matrix of a second heat transfer structure;  
 a solder preform disposed on the matrix; and  
 a transition between the matrix and the solder preform, wherein the transition is selected from an interface and a concentration gradient.  
   
   
   
       7 . The method according to  claim 6 , further including: 
 before disposing the heat transfer subsystem between the die and the heat spreader, heating the heat spreader above ambient, wherein bonding is carried out for the heat transfer subsystem at a temperature of about (T TIM -T AMB )/2, wherein T TIM  is the melting Centigrade temperature of the solder preform, and wherein T AMB  is the Centigrade ambient temperature.    
   
   
       8 . The method according to  claim 6 , wherein bonding includes reflowing the plurality of first heat transfer structures against the die, wherein the plurality of first heat transfer structures is selected from a base solder alloyed with an active element material, indium, tin, silver, tin-silver, tin-indium, silver-indium, tin-silver-indium, and combinations thereof.  
   
   
       9 . The method according to  claim 6 , further including: 
 disposing the die on a mounting substrate to form a package.    
   
   
       10 . The method according to  claim 6 , further including: 
 coupling the die with at least one of an input device and an output device.    
   
   
       11 . The method according to  claim 6 , further including: 
 coupling the die with a computing system included in one of a computer, a wireless communicator, a hand-held device, an automobile, a locomotive, an aircraft, a watercraft, and a spacecraft.    
   
   
       12 . A computing system comprising: 
 a heat spreader;    a die disposed below the heat spreader;    a heat transfer composite disposed above and on the die and below and on the heat spreader, wherein the heat transfer composite includes: 
 a plurality of first heat transfer structures disposed in a polymer matrix of a second heat transfer structure, wherein the polymer matrix is disposed on the die; and  
 a solder preform disposed on the polymer matrix, wherein the solder preform is disposed on the heat spreader; and  
 at least one of an input device and an output device.  
   
   
   
       13 . The computing system according to  claim 12 , wherein the computing system is disposed in one of a computer, a wireless communicator, a hand-held device, an automobile, a locomotive, an aircraft, a watercraft, and a spacecraft.  
   
   
       14 . The computing system according to  claim 12 , wherein the die is selected from a data storage device, a digital signal processor, a micro controller, an application specific integrated circuit, and a microprocessor.