Heat dissipation device and a method for manufacturing same

Abstract

A heat dissipation device includes a first copper sheet and a second copper sheet. The first copper sheet includes a number of first recesses and the second copper sheet includes a number of corresponding second recesses. The second copper sheet is fixed on the first copper sheet and an airtight receiving cavity is formed by each first recess and each the second recess, a working fluid in the airtight receiving cavity carries unwanted heat away.

What is claimed is: 
     
         1 . A heat dissipation device comprising:
 a first copper sheet comprising a plurality of first recesses;   a second copper sheet comprising a plurality of second recesses, the second recesses corresponding with the first recesses, the second copper sheet being fixed on the first copper sheet and each the second recesses facing the corresponding first recesses, an airtight receiving cavity being formed by each of the first recesses and the second recesses, the second copper sheet being fixed on the first copper sheet with adhesive, the adhesive forms a part of an inner wall of the airtight receiving cavity; and   a working fluid received in the airtight receiving cavity.   
     
     
         2 . The heat dissipation device of  claim 1 , wherein the first copper sheet comprises a first surface, the second copper sheet comprises a second surface facing the first surface, the first recesses are randomly distributed on the first surface. 
     
     
         3 . The heat dissipation device of  claim 2 , wherein the first copper sheet comprises a plurality of first ribs, the first ribs are formed between each two adjacent first recesses, the second copper sheet comprises a plurality of second ribs, the second ribs are formed between each two adjacent second recesses, the first ribs are corresponding with the second ribs. 
     
     
         4 . The heat dissipation device of  claim 1 , wherein the adhesive is low temperature solder paste. 
     
     
         5 . The heat dissipation device of  claim 4 , wherein the adhesive comprises a molten resin material doped with metal particles, the metal particle is selected from the group comprising tin, bismuth and any combination thereof. 
     
     
         6 . The heat dissipation device of  claim 5 , wherein a weight ratio of tin in the adhesive is in the range from about 37% to about 38%, a weight ratio of bismuth in the adhesive is in the range from about 51% to about 52%, and a weight ratio of molten resin in the adhesive is in the range from about 4% to about 6%. 
     
     
         7 . The heat dissipation device of  claim 3 , wherein the adhesive is sandwiched between the first ribs and the second ribs. 
     
     
         8 . The heat dissipation device of  claim 1 , wherein a cross section of the first and second recesses is an arc or a semi circle. 
     
     
         9 . A heat dissipation device, comprising:
 a first copper sheet comprising a plurality of first recesses;   a second copper sheet comprising a plurality of second recesses, the second recesses being corresponding with the first recesses, the second copper sheet being fixed on the first copper sheet such that each of the second recesses mate with the corresponding first recesses to define a plurality of an airtight receiving cavities being formed by each the first recess and the second recess; and   a working fluid in each of the airtight receiving cavities;   wherein the first and second copper sheets are configured to transmit external heat from an outer surface toward the working fluid, thereby providing a heat sink.   
     
     
         10 . A method for manufacturing the heat dissipation device, the method comprising:
 providing a first copper base and a second copper base, the first copper base comprises a first surface, the second copper base comprises a second surface facing toward the first surface;   processing the first surface to form a number of first recess and a number of ribs between each two adjacent first recesses,   processing the second surface to form a number of second recesses, the second recesses and the first recesses have the same shape and size;   providing an adhesive on the ribs of the first copper sheet;   providing a working fluid in the first recesses of the first copper sheet;   pressing the second copper sheet on the adhesive, and the second copper sheet is fixed with the first copper sheet by the adhesive, each the first recesses are in communication with the second recesses, each of the first recesses and the second recesses together form an airtight receiving cavity;   solidifying the adhesive.   
     
     
         11 . The method of  claim 9 , wherein the a depth of each first recesses is smaller than a thickness of the first copper sheet, a depth of each second recesses is smaller than a thickness of the second copper sheet. 
     
     
         12 . The method of  claim 10 , wherein the adhesive is low temperature solder paste. 
     
     
         13 . The method of  claim 12 , wherein the adhesive comprises of molten resin material doped with metal particles, the metal particle is selected from the group comprising tin, bismuth and any combination thereof. 
     
     
         14 . The method of  claim 13 , wherein a weight ratio of tin in the adhesive is in the range from about 37% to about 38%, a weight ratio of bismuth in the adhesive is in the range from about 51% to about 52%, and a weight ratio of molten resin in the adhesive is in the range from about 4% to about 6%. 
     
     
         15 . The method of  claim 13 , wherein the working fluid at least is able to select from the group comprising water, methanol, ethanol, acetone, ammonia, paraffin, oil, and chlorofluorocarbons.