Metal based thermal dissipator having enhanced thermal radiation, and methods for producing the same

Abstract

A composite thermal dissipator and a method for fabricating the same is disclosed. The composite thermal dissipator includes a molded polydimethylsiloxane (PDMS) composite material composed of a powdered metal mixed with PDMS. The method for fabricating a composite thermal dissipator includes mixing a powdered copper into liquid PDMS to form a liquid mixture, and pouring the liquid mixture into a sacrificial wax mold. The sacrificial wax mold includes wax shaped to be complementary to the composite thermal dissipator. The method also includes curing the liquid mixture within the sacrificial wax mold, and removing the composite thermal dissipator from the sacrificial wax mold by melting away the wax.

What is claimed is: 
     
         1 . A method for fabricating a composite thermal dissipator, comprising:
 mixing a powdered copper into liquid polydimethylsiloxane (PDMS) to form a liquid mixture;   pouring the liquid mixture into a sacrificial wax mold, the sacrificial wax mold comprising wax shaped to be complementary to the composite thermal dissipator;   curing the liquid mixture within the sacrificial wax mold; and   removing the composite thermal dissipator from the sacrificial wax mold by melting away the wax.   
     
     
         2 . The method of  claim 1 , further comprising:
 covering the sacrificial wax mold with a substrate such that the substrate is in contact with the liquid mixture;   wherein the composite thermal dissipator comprises the substrate.   
     
     
         3 . The method of  claim 1 , wherein the powdered copper has a particle size of less than 75 μm. 
     
     
         4 . The method of  claim 1 , wherein the weight ratio of powdered copper to PDMS is between 3.7 and 4. 
     
     
         5 . The method of  claim 1 , wherein the composite thermal dissipator comprises a plurality of fins, each fin having a perimeter and a cross-sectional area, wherein the perimeter-to-cross-sectional-area ratio is at least 400 m −1 . 
     
     
         6 . A method for fabricating a composite thermal dissipator, comprising:
 mixing a powdered metal into liquid polydimethylsiloxane (PDMS) to form a liquid mixture;   pouring the liquid mixture into a mold, the mold shaped to be complementary to the composite thermal dissipator;   curing the liquid mixture within the mold; and   removing the composite thermal dissipator from the mold.   
     
     
         7 . The method of  claim 6 :
 wherein the mold is a sacrificial wax mold comprising wax shaped to be complementary to the composite thermal dissipator; and   wherein removing the composite thermal dissipator from the mold comprises melting away the wax of the sacrificial wax mold.   
     
     
         8 . The method of  claim 6 , further comprising:
 covering the mold with a substrate such that the substrate is in contact with the liquid mixture;   wherein the composite thermal dissipator comprises the substrate.   
     
     
         9 . The method of  claim 6 , wherein the powdered metal is powdered copper. 
     
     
         10 . The method of  claim 6 , wherein the powdered metal has a particle size of less than 75 μm. 
     
     
         11 . The method of  claim 6 , wherein the weight ratio of powdered metal to PDMS is between 3.7 and 4. 
     
     
         12 . The method of  claim 6 , wherein the composite thermal dissipator comprises a plurality of fins, each fin having a perimeter and a cross-sectional area, wherein the perimeter-to-cross-sectional-area ratio is at least 400 m −1 . 
     
     
         13 . The method of  claim 6 , wherein the liquid mixture is cured within the mold at room temperature. 
     
     
         14 . A composite thermal dissipator, comprising a molded PDMS composite material composed of a powdered metal mixed with PDMS. 
     
     
         15 . The composite thermal dissipator of  claim 14 , further comprising a substrate coupled to the molded composite material. 
     
     
         16 . The composite thermal dissipator of  claim 14 , wherein the powdered metal is powdered copper. 
     
     
         17 . The composite thermal dissipator of  claim 16 , wherein the powdered metal has a particle size of less than 75 μm. 
     
     
         18 . The composite thermal dissipator of  claim 17 , wherein the weight ratio of powdered metal to PDMS is between 3.7 and 4. 
     
     
         19 . The composite thermal dissipator of  claim 14 , further comprising a plurality of fins, each fin having a perimeter and a cross-sectional area, wherein the perimeter-to-cross-sectional-area ratio is at least 400 m −1 .