Low-Profile Heat Sink with Fine-Structure Patterned Fins for Increased Heat Transfer

Abstract

In one embodiment, a device for transferring heat comprises a base member and a first array of pin fins supported by the base member, the pin fins having an aspect ratio of not less than about 10, and the pin fins being not more than about 0.3 mm in equivalent diameter and not more than about 3 mm in length, either one or both of the base member and pin fins comprising a metallic or semiconductor material. To form this device, a substrate is provided. A pattern is formed on the substrate, the pattern having holes therein or in the form of dots with cross-sectional dimensions of not more than about 0.3 mm. Pin fins supported by the substrate are formed, where the pin fins have an aspect ratio of not less than about 10, and not more than about 0.3 mm in equivalent diameter and not more than about 3 mm in length. Either one or both of the base member and pin fins comprise a metallic or semiconductor material. The pattern is then removed.

1 . A device for transferring heat comprising:
 a base member; and   a first array of pin fins supported by said base member, said pin fins having an aspect ratio of not less than about 10, and said pin fins being not more than about 0.3 mm in equivalent diameter and not more than about 3 mm in length, either one or both of said base member and pin fins comprising a metallic or semiconductor material.   
     
     
         2 . The device of  claim 1 , said pin fins having an aspect ratio of not less than about 20. 
     
     
         3 . The device of  claim 1 , said pin fins having a perimeter P, wherein said equivalent diameter of the pin fins is P/π. 
     
     
         4 . The device of  claim 1 , said pin fins having a length or lengths less than about 1 mm. 
     
     
         5 . The device of  claim 1 , said pin fins having an equivalent diameter less than about 0.1 mm. 
     
     
         6 . The device of  claim 1 , said pin fins created by a Deep Reactive Ion Etching process. 
     
     
         7 . The device of  claim 1 , further comprising a second array of pin fins supported by the base member. 
     
     
         8 . The device of  claim 1 , the base member comprising a layer of silicon material, said device further comprising a second member bonded to the base member for conducting heat between the pin fins and the second member through the base member. 
     
     
         9 . The device of  claim 1 , wherein said base member defines one or more holes therein for enhancing air flow turbulence and heat convection to transfer heat. 
     
     
         10 . The device of  claim 1 , wherein said first array of pin fins arranged in sub-arrays with gutters between the sub-arrays for enhancing heat convection to transfer heat. 
     
     
         11 . The device of  claim 1 , further comprising a fan for generating air flow in spacings between the pin fins. 
     
     
         12 . A device for transferring heat comprising:
 a heat spreader; and   a plurality of heat transfer elements supported by and thermally connected to said on said heat spreader, each element comprising a base member, and an array of pin fins supported by said base member, said pin fins having an aspect ratio of not less than about 10 and said pin fins being not more than about 0.3 mm in equivalent diameter and not more than about 3 mm in length, said base members and pin fins comprising a metallic or semiconductor material.   
     
     
         13 . The device of  claim 12 , said base members comprising plates with edges, said plurality of heat transfer elements supported by and thermally connected to said on said heat spreader through the edges of said base members of the elements. 
     
     
         14 . A device for transferring heat comprising:
 a set of fins arranged in a radial pattern; and   a plurality of heat transfer elements supported on said fins, each element comprising a base member, and an array of pin fins supported by said base member, said pin fins having an aspect ratio of not less than about 10, and said pin fins being not more than about 0.3 mm in equivalent diameter and not more than about 3 mm in length, said base members and pin fins comprising a metallic or semiconductor material.   
     
     
         15 . A method for making a device that dissipates heat in air, comprising:
 providing a substrate;   forming a pattern on the substrate, said pattern having holes therein or in the form of dots with cross-sectional dimensions of not more than about 0.3 mm; and   causing pin fins supported by the substrate to be formed, said pin fins having an aspect ratio of not less than about 10, and said pin fins being not more than about 0.3 mm in equivalent diameter and not more than about 3 mm in length, said base member and pin fins comprising a metallic or semiconductor material; and   removing said pattern.   
     
     
         16 . The method of  claim 15 , wherein said pattern is in the form of dots and formed by means of a photolithographic process, and said pin fins are formed by means of an etching process. 
     
     
         17 . The method of  claim 15 , wherein said pin fins are formed by means of a Deep Reactive Ion etching process. 
     
     
         18 . The method of  claim 15 , wherein said pattern have holes therein and formed by means of an UV photolithographic or nano-imprinting process, said causing including depositing growing seeds in said holes, and growing nanotubes or nanowires on top of the seeds. 
     
     
         19 . The method of  claim 18 , wherein said nanotubes or nanowires have diameters not more than 1 micron. 
     
     
         20 . A method for transferring heat, comprising:
 providing a device for transferring heat which comprises:   a base member; and   a first array of pin fins supported by said base member, said pin fins having an aspect ratio of not less than about 10, and said pin fins being not more than about 0.3 mm in equivalent diameter and not more than about 3 mm in length, said base member and pin fins comprising a metallic or semiconductor material;   locating said base member relative to an object to transfer heat between the pin fins and the object and so that said pin fins are in contact with a gaseous environment to enable heat transfer between the pin fins and the gaseous environment.   
     
     
         21 . The method of  claim 20 , wherein heat is transferred from the object to the pin fins, and said pin fins are in contact with air. 
     
     
         22 . The method of  claim 20 , wherein heat is transferred from the pin fins to the object, and said pin fins are in contact with air. 
     
     
         23 . The method of  claim 20 , wherein heat is by means of conduction or radiation or both.