Graphene based filler material of superior thermal conductivity for chip attachment in microstructure devices

Abstract

An integrated circuit chip attachment in a microstructure device is accomplished through the use of an adhesive-based material in which graphene flakes are incorporated. This results in superior thermal conductivity. The spatial orientation of the graphene flakes is controlled, for example by adhering polar molecules to the graphene flakes and exposing the flakes to an external force field, so that the graphene flakes have desired orientations under the integrated circuit chip, alongside of the integrated circuit chip and above the integrated circuit chip.

What is claimed is: 
     
         1 . A microstructure device, comprising:
 a substrate having a surface;   a microstructure device chip positioned above said surface, said microstructure chip having formed therein at least one circuit element; and   an intermediate heat transfer layer positioned between said surface of said substrate and said microstructure device chip, said intermediate heat transfer layer comprising graphene flakes.   
     
     
         2 . The microstructure device of  claim 1 , wherein said intermediate heat transfer layer comprises a glue substance so as to mechanically connect said microstructure device chip to said substrate. 
     
     
         3 . The microstructure device of  claim 1 , wherein a concentration in atomic percent of carbon atoms of said graphene flakes in said intermediate heat transfer layer is greater than a concentration of silver (Ag) atoms and/or lead (Pb) atoms. 
     
     
         4 . The microstructure device of  claim 3 , wherein said intermediate heat transfer layer is a lead-free material. 
     
     
         5 . The microstructure device of  claim 1 , wherein said intermediate heat transfer layer is formed above the entire surface area of said surface. 
     
     
         6 . The microstructure device of  claim 1 , wherein said intermediate heat transfer layer comprises at first portion including a first plurality of said graphene flakes having a first averaged spatial orientation that is aligned to a first spatial direction. 
     
     
         7 . The microstructure device of  claim 6 , wherein said first spatial direction is perpendicular to said surface. 
     
     
         8 . The microstructure device of  claim 6 , wherein said first spatial direction is parallel to said surface. 
     
     
         9 . The microstructure device of  claim 6 , wherein said intermediate heat transfer layer further comprising a second portion including a second plurality of graphene flakes having a second averaged spatial orientation that is aligned to a second spatial direction that is different from said first spatial direction. 
     
     
         10 . The microstructure device of  claim 9 , wherein said first and second spatial directions are substantially orthogonal. 
     
     
         11 . The microstructure device of  claim 9 , wherein said first and second portions are provided laterally adjacent to each other. 
     
     
         12 . The microstructure device of  claim 9 , wherein said first and second portions form a stacked configuration. 
     
     
         13 . The microstructure device of  claim 1 , further comprising a second microstructure device chip positioned above said microstructure device chip and a second intermediate heat transfer layer formed between said microstructure device chip and said second microstructure device chip, wherein said second intermediate heat transfer layer comprises graphene flakes. 
     
     
         14 . A method, comprising:
 positioning a microstructure device chip above a surface of a substrate; and   providing therebetween a filler material that is thermally conductive and comprises graphene flakes.   
     
     
         15 . The method of  claim 14 , wherein said thermally conductive filler material comprises a glue substance incorporating therein said graphene flakes. 
     
     
         16 . The method of  claim 14 , wherein providing comprises, prior to positioning said microstructure device chip above said surface, forming said filler material as a layer above a wafer that comprises a plurality of chips including said microstructure device chip. 
     
     
         17 . The method of  claim 14 , wherein said thermally conductive filler material substantially completely covers said surface. 
     
     
         18 . The method of  claim 14 , wherein providing comprises depositing said filler material in a deformable state and exposing a first portion of said filler material in said deformable state to a first spatially oriented force field so as to allow graphene flakes in said first portion to take on a first averaged spatial orientation corresponding to said first force field. 
     
     
         19 . The method of  claim 18 , further comprising curing said filler material so as to permanently set said averaged spatial orientation. 
     
     
         20 . The method of  claim 18 , further comprising exposing a second portion of said filler material to a second spatially oriented force field so as to allow graphene flakes in said second portion to take on a second averaged spatial orientation corresponding to said second force field. 
     
     
         21 . A microstructure device, comprising:
 a substrate having a surface;   a microstructure device chip positioned above said surface, said microstructure chip having formed therein at least one circuit element; and   an intermediate heat transfer layer positioned between said surface of said substrate and said microstructure device chip, said intermediate heat transfer layer comprising a plurality of graphene flakes, said graphene flakes have a first permanently set averaged spatial orientation in a region of the intermediate heat transfer layer underneath said microstructure device chip.   
     
     
         22 . The structure of  claim 21 , wherein said graphene flakes have a second permanently set averaged spatial orientation, different from said first permanently set averaged spatial orientation, in a region of the intermediate heat transfer layer that is not underneath said microstructure device chip. 
     
     
         23 . The structure of  claim 21 , wherein said intermediate heat transfer layer comprises a first layer wherein said graphene flakes have the first permanently set averaged spatial orientation and a second layer wherein said graphene flakes have a second permanently set averaged spatial orientation different from said first permanently set averaged spatial orientation. 
     
     
         24 . The structure of  claim 23 , wherein said graphene flakes having the first permanently set averaged spatial orientation are located in the region of the first layer that is underneath said microstructure device chip, and wherein said graphene flakes in the first layer have the second permanently set averaged spatial orientation in a region of the first layer that is not underneath said microstructure device chip. 
     
     
         25 . The structure of  claim 21 , further comprising a heat transfer material positioned adjacent side edges of said microstructure device chip, said heat transfer material comprising a plurality of graphene flakes, said graphene flakes have a second permanently set averaged spatial orientation different from said first permanently set averaged spatial orientation.