Heat Pipe and Making Method Thereof

Abstract

A heat pipe and the method thereof are provided. The heat pipe ( 1 ) comprises a pipe body ( 12 ), a cavity ( 14 ) and a porous capillary diversion layer ( 18 ). The pipe body ( 12 ) has a first open ( 122 ) and a third open ( 124 ), and the cavity ( 14 ) has a second open ( 142 ). The first open ( 122 ) and the second open ( 142 ) are bonded together, and the third open ( 124 ) is sealed to form the heat pipe ( 1 ). The heat pipe comprises working liquid in it. The sectional area of the cavity ( 14 ) is larger than that of the pipe body ( 12 ). And the cavity ( 14 ) has a planar end ( 144 ).

1 . A heat pipe, applied to a light emitting diode (LED), the heat pipe comprising:
 a tube having a first open, the diameter of the tube being smaller than a distance of 10 mm;   a chamber having a second open, the second open and the first open being tightly joined together to form a sealed space via the tube and the chamber; and   a porous capillary diversion layer, formed in the tube and the chamber;   
     wherein the sealed space contains a working fluid, and a cross-section area of the chamber is larger than a cross-section area of the tube. 
   
   
       2 . The heat pipe of  claim 1 , wherein the tube and the chamber are formed in one piece. 
   
   
       3 . The heat pipe of  claim 1 , wherein the chamber comprises a concave and an upper cover, and the upper cover is engaged with the concave and the upper cover has the second open. 
   
   
       4 . The heat pipe of  claim 3 , wherein the concave is made through a process of powder metallurgy, stamping, injection molding, casting, or machining. 
   
   
       5 . The heat pipe of  claim 1 , wherein the chamber has a flat end. 
   
   
       6 . The heat pipe of  claim 1 , wherein the porous capillary diversion layer is made by sintering a copper powder, a nickel powder, a silver powder, a metallic powder plated with copper, nickel, silver, or other similar metallic powders. 
   
   
       7 . The heat pipe of  claim 1 , wherein the porous capillary diversion layer comprises a metallic pellet layer and a metallic net body, the metallic pellet layer is formed on the inner wall of the tube and the inner wall of the chamber by sintering, and the metallic net body is disposed upon the metallic pellet layer. 
   
   
       8 . The heat pipe of  claim 1 , wherein the porous capillary diversion layer comprises a wavy carped metal cloth and a flat metal net fabric layer, the wavy carped metal cloth is spread on the inner wall of the tube and the inner wall of the chamber, and the flat metal net fabric layer is disposed on the wavy carped metal cloth. 
   
   
       9 . The heat pipe of  claim 8 , wherein the wavy carped of the wavy carped metal cloth is in a form of triangle, rectangle, trapezium or wave. 
   
   
       10 . The heat pipe of  claim 1 , wherein the porous capillary diversion layer comprises a plurality of tiny notches formed on the inner wall of the tube and the inner wall of the chamber. 
   
   
       11 . The heat pipe of  claim 1 , wherein the porous capillary diversion layer comprises a plurality of tiny notches and a metallic sintered layer, the tiny notches are formed on the inner wall of the chamber, and the metallic sintered layer is formed on the inner wall of the tube and the metallic sintered layer is welded with the tiny notches. 
   
   
       12 . A method of making a heat pipe, comprising the steps of:
 (a) providing a tube having a first open and a third open;   (b) providing a chamber having a second open;   (c) tightly joining the first open of the tube and the second open of the chamber together to form a semi-finished heat pipe;   (d) vacuuming the semi-finished heat pipe; and   (e) sealing the third open;   
     wherein the inner wall of the semi-finished heat pipe comprises a porous capillary diversion layer, the semi-finished heat pipe contains a working fluid, and the cross-section area of the chamber is larger than the cross-section area of the tube. 
   
   
       13 . The method of the  claim 12 , wherein the chamber has a flat end. 
   
   
       14 . The method of  claim 12 , wherein in step (c), the tight joining is performed through a process of welding, soldering, machine fastening, or gluing. 
   
   
       15 . The method of  claim 12 , wherein the working fluid is poured into the semi-finished heat pipe before or after step (d) is performed. 
   
   
       16 . The method of  claim 12 , wherein a sintered metallic powder layer is formed on the inner wall of the chamber, and the porous capillary diversion layer is formed by the following steps of:
 interposing a center pillar into the semi-finished heat pipe from the third open and the center pillar being approximately tightly against the sintered metallic powder layer;   filling a first metallic powder between the center pillar and the semi-finished heat pipe;   performing a sintering process to make the first metallic powder and the metallic powder mutually welded to form the porous capillary diversion layer; and   getting the center pillar out of the semi-finished heat pipe.   
   
   
       17 . The method of  claim 12 , wherein the inner wall of the chamber has a plurality of tiny notches, and the porous capillary diversion layer is formed by the following steps of:
 interposing a center pillar into the semi-finished heat pipe from the third open and the center pillar being approximately tightly against the plurality of tiny notches;   filling a second metallic powder between the center pillar and the semi-finished heat pipe;   performing a sintering process to make the second metallic powder and the plurality of tiny notches mutually welded to form the porous capillary diversion layer; and   getting the center pillar out of the semi-finished heat pipe.   
   
   
       18 . The method of  claim 16  or  17 , wherein the first metallic powder or the second metallic powder is a copper powder, a nickel powder, a silver powder, a metallic powder plated with copper, nickel, silver metal powder, or other metallic powders. 
   
   
       19 . The method of  claim 12 , wherein the porous capillary diversion layer is formed by the following step of:
 using a machining process to make the plurality of tiny notches on the inner wall of the tube and the inner wall of the chamber to form the porous capillary diversion layer.   
   
   
       20 . The method of  claim 12 , wherein the porous capillary diversion layer is formed by the following steps of:
 sintering a plurality of metallic pellets on the inner wall of the tube and the inner wall of the chamber; and   disposing a metallic net body on the plurality of metallic pellets to form the porous capillary diversion layer.   
   
   
       21 . The method of  claim 12 , wherein the porous capillary diversion layer is formed by the following steps of:
 laying a wavy carped metal cloth on the inner wall of the tube and the inner wall of the chamber; and   disposing a flat metal net fabric layer on the wavy carped metal cloth to form the porous capillary diversion layer.   
   
   
       22 . The method of  claim 12 , wherein step (b) comprises the steps of:
 providing a concave;   providing a upper cover, the upper cover has the second open; and   engaging the upper cover and the concave to form the chamber.   
   
   
       23 . The method of  claim 22 , wherein a first sintered metal layer is formed on the concave, a second sintered metal layer is formed on the upper cover, and the first sintered metal layer is engaged with the second sintered metal layer. 
   
   
       24 . The method of  claim 22 , wherein a plurality of first tiny notches is formed on the concave, a plurality of second tiny notches is formed on the upper cover, and the plurality of first tiny notches is engaged with the plurality second of tiny notches. 
   
   
       25 . The method of  claim 22 , wherein the concave is made through a process of powder metallurgy, stamping, injection molding, casting, or machining. 
   
   
       26 . A method of making a heat pipe, comprising the steps of:
 (A) providing a first tube having an open and a closed end;   (B) shrinking the neck of the first tube to form a chamber and a second tube, the chamber and the second tube being mutually through, wherein the chamber comprises the closed end, and the second comprises the open;   (C) vacuuming the chamber and the second tube; and   (D) sealing the open;   
     wherein the inner wall of the chamber and the inner wall of the second tube comprise a porous capillary diversion layer, the chamber and the second tube contain a working fluid, a cross-section area of the chamber is larger than the cross-section area of the second tube. 
   
   
       27 . The method of  claim 26 , wherein the closed end is flat. 
   
   
       28 . The method of  claim 26 , wherein step (B) is operated in a temperature range from 400° C. to 600° C. 
   
   
       29 . The method of  claim 26 , further comprising:
 after step (A) is performed, forming the porous capillary diversion layer on the inner wall of the first tube.   
   
   
       30 . The method of  claim 29 , wherein the porous capillary diversion layer is formed by the following steps of:
 disposing a first metallic powder into the first tube;   interposing a center pillar into the first tube from the open and the center pillar being approximately tightly against on the first metallic powder;   filling a second metallic powder between the center pillar and the inner wall of the first tube;   performing a sintering process to make the first metallic powder and the second metallic powder mutually welded to form the porous capillary diversion layer; and   getting the center pillar out of the first tube.