Thermal interface pad and production method thereof, and heat dissipating system

Abstract

A thermal interface pad, includes a substrate and carbon nanowires, where the substrate has a first surface and a second surface opposite to the first surface, the carbon nanowires are disposed on both the first surface and the second surface of the substrate, and the carbon nanowires are arranged in an array. The substrate includes a flexible composite metal film, or a material of the substrate includes at least one of flexible graphite and a solder alloy, and the flexible composite metal film is a flexible metal film with a surface coated with nickel, silver or gold. The thermal interface material has high thermal conductivity, may be attachable and affixed, and is easy for industrial production and use. The embodiments of the present invention further provide a production method of a thermal interface material, which features a large production volume, low costs, and easy control of product quality.

What is claimed is: 
     
         1 . A thermal interface pad, comprising:
 a substrate having a first surface and a second surface opposite to the first surface;   carbon nanowires disposed on both the first surface and the second surface of the substrate and are arranged in an array; and   wherein the substrate comprises a flexible composite metal film, or a material of the substrate comprises at least one of flexible graphite and a solder alloy, and the flexible composite metal film is a flexible metal film with a surface coated with nickel, silver or gold.   
     
     
         2 . The thermal interface pad according to  claim 1 , wherein the carbon nanowires are perpendicular to at least one surface of the first surface and the second surface of the substrate. 
     
     
         3 . The thermal interface pad according to  claim 1 , wherein the carbon nanowires comprise carbon nanofibers, or multi-walled carbon nanotubes, or both. 
     
     
         4 . The thermal interface pad according to  claim 3 , wherein the carbon nanofibers have a diameter of 50 to 200 nm. 
     
     
         5 . The thermal interface pad according to  claim 3 , wherein the multi-walled carbon nanotubes have a diameter of 1 to 50 nm. 
     
     
         6 . The thermal interface pad according to  claim 1 , wherein the flexible metal film comprises at least one of copper foil, aluminum foil, nickel foil, a copper alloy sheet, and a stainless steel sheet. 
     
     
         7 . The thermal interface pad according to  claim 1 , wherein the flexible composite metal film has a thickness of 10 to 200 μm. 
     
     
         8 . The thermal interface pad according to  claim 1 , wherein the flexible graphite is highly oriented pyrolytic graphite. 
     
     
         9 . The thermal interface pad according to  claim 1 , wherein the flexible graphite has a thickness of 10 to 200 μm. 
     
     
         10 . The thermal interface pad according to  claim 9 , wherein the carbon nanowires disposed on at least one surface of the first surface and the second surface of the substrate have a length of 20 to 125 μm. 
     
     
         11 . The thermal interface pad according to  claim 1 , wherein the solder alloy is an indium-based alloy or a gallium-based alloy. 
     
     
         12 . The thermal interface pad according to  claim 11 , wherein the substrate made from the solder alloy has a thickness of 10 to 50 μm. 
     
     
         13 . The thermal interface pad according to  claim 12 , wherein the carbon nanowires disposed on the first surface of the substrate have a length of 0.5 to 10 μm, and the carbon nanowires disposed on the second surface of the substrate have a length of 50 to 150 μm. 
     
     
         14 . The thermal interface pad according to  claim 13 , wherein:
 the thermal interface pad further comprises a vapor deposited layer or a sputtered layer located on one side of the second surface of the substrate;   the carbon nanowires located on the second surface penetrate into the vapor deposited layer or the sputtered layer; and   at least one portion of the carbon nanowires on the second surface penetrates through the vapor deposited layer or the sputtered layer and projects out of the vapor deposited layer or the sputtered layer, and the portion of the carbon nanowires projecting out of the vapor deposited layer or the sputtered layer has a length of 0.5 to 10 μm.   
     
     
         15 . The thermal interface pad according to  claim 14 , wherein a total cross-sectional area of the carbon nanowires penetrating into the vapor deposited layer or the sputtered layer accounts for 50% to 99% of an area of the second surface of the substrate. 
     
     
         16 . A heat dissipating system, comprising:
 a heat emitting element;   a heat radiator;   a thermal pad comprising the thermal interface pad according to  claim 1 ; and   wherein the heat emitting element is located on one side of the heat radiator, and the thermal pad is affixed between the heat emitting element and the heat radiator, so that the heat emitting element transfers heat through the thermal pad to the heat radiator for heat dissipation.