Flat type heat pipe and method for manufacturing the same

Abstract

An exemplary flat type heat pipe includes a hollow, flattened casing and a first wick structure and a second wick structure received in the casing. The casing includes a top plate and a bottom plate opposite to the top plate. The first wick structure includes a plurality of spaced protruding portions and grooves between every two adjacent protruding portions. The second wick structure is made of sintered metal powder. The first and second wick structures are disposed at inner sides of the bottom and top plates of the casing, respectively. The first and second wick structures contact each other. The casing defines two vapor channels at opposite lateral sides of the combined first and second wick structures, respectively.

1 . A flat type heat pipe comprising:
 a hollow, flattened casing, comprising a top plate and a bottom plate opposite to the top plate; and   a first wick structure and a second wick structure formed in the casing, the first wick structure comprising a plurality of spaced protruding portions and grooves between the protruding portions, the second wick structure being made of sintered metal powder, the first and second wick structures disposed at inner surfaces of the bottom and top plates of the casing, respectively, the first and second wick structures contacting each other, the casing defining two vapor channels at opposite lateral sides of the combined first and second wick structures, respectively.   
     
     
         2 . The flat type heat pipe of  claim 1 , wherein bottoms of the protruding portions of the first wick structure extend from the bottom plate, a top of the second wick structure is attached to the top plate, and a top of at least one of the protruding portions of the first wick structure is attached to a bottom of the second wick structure not in contact with the top plate. 
     
     
         3 . The flat type heat pipe of  claim 1 , wherein the first wick structure is aligned with the second wick structure, and the second wick structure abuts the centermost plurality of the protruding portions of the first wick structure. 
     
     
         4 . The flat type heat pipe of  claim 3 , wherein the second wick structure tapers from a top thereof farthest away from the first wick structure toward a bottom thereof in contact with the first wick structure, and the bottom of the second wick structure in contact with the first wick structure forms a rounded ridge attached to the corresponding protruding portions of the first wick structure. 
     
     
         5 . The flat type heat pipe of  claim 3 , wherein the tops of the protruding portions of the first wick structure abut a central portion of the second wick structure. 
     
     
         6 . The flat type heat pipe of  claim 1 , wherein the first wick structure obliquely faces the second wick structure. 
     
     
         7 . The flat type heat pipe of  claim 6 , wherein the second wick structure tapers from a top thereof farthest away from the first wick structure toward a bottom thereof attached to the first wick structure, and the bottom of the second wick structure is attached to a plurality of the protruding portions of at one side of the first wick structure. 
     
     
         8 . The flat type heat pipe of  claim 6 , wherein the second wick structure is generally cuboid, and one side of a bottom of the second wick structure is attached to a plurality of the protruding portions of the first wick structure. 
     
     
         9 . The flat type heat pipe of  claim 1 , wherein the second wick structure is substantially triangular prism-shaped or cuboid, and a bottom of the second wick structure not in contact with the casing is attached to the first wick structure. 
     
     
         10 . The flat type heat pipe of  claim 1 , wherein the protruding portions are aligned with each other, with ends of the protruding portions closer to the second wick structure being substantially coplanar with each other. 
     
     
         11 . The flat type heat pipe of  claim 1 , wherein each of the protruding portions is elongated, and a transverse width of the protruding portion decreases from a bottom thereof at the bottom plate of the casing to a top thereof farthest away from the bottom plate. 
     
     
         12 . The flat type heat pipe of  claim 1 , wherein a part of at least one of the protruding portions is embedded in the second wick structure. 
     
     
         13 . A method for manufacturing a flat type heat pipe, the method comprising:
 providing a cylindrical mandrel, the mandrel defining an elongated notch and an elongated cutout in a circumferential surface thereof, the notch and the cutout located directly opposite each other across a center axis of the mandrel;   providing a cylindrical and hollow tube, an elongated protruding plate disposed on a part of an inner surface of the tube, the protruding plate being etched and thereby comprising a plurality of protruding portions and grooves between every two adjacent protruding portions, the protruding portions and the grooves cooperatively forming a first wick structure preform, an inner diameter of the tube being substantially equal to an outer diameter of the mandrel;   inserting the mandrel into the tube, wherein the protruding portions are received in the notch of the mandrel;   filling an amount of metal powder into the cutout of the mandrel in the tube, and sintering the metal powder to form a second wick structure preform;   drawing the mandrel out of the tube, wherein the first and second wick structure preforms remain in the tube, and face each other;   injecting a working medium into the tube, and evacuating and sealing the tube; and   flattening the tube such that the first and second wick structure preforms become formed a first wick structure and a second wick structure, respectively, wherein the second wick structure contacts at least one of the protruding portions of the first wick structure with the protruding portions being simultaneously substantially aligned with each other, thus forming a flat type heat pipe, wherein the flat type heat pipe defines two vapor channels at opposite lateral sides of the combined first and second wick structures, respectively.   
     
     
         14 . The method for manufacturing a flat type heat pipe of  claim 13 , wherein the cutout defines a generally rainbow-shaped cross section, and after the mandrel is drawn out of the tube, the second wick structure preform has a generally rainbow-shaped cross section. 
     
     
         15 . The method for manufacturing a flat type heat pipe of  claim 14 , wherein after the tube is flattened, the second wick structure is generally cuboid. 
     
     
         16 . The method for manufacturing a flat type heat pipe of  claim 13 , wherein an inmost extremity of the cutout is planar, and after the mandrel is drawn out of the tube, a transverse cross section of the second wick structure preform comprises a straight line and an arcuate line connecting the straight line, with the arcuate line corresponding to a portion of the second wick structure attached to the inner surface of the tube. 
     
     
         17 . The method for manufacturing a flat type heat pipe of  claim 16 , wherein after the tube is flattened, the second wick structure generally tapers from one side thereof farthest away from the first wick structure toward another side thereof in contact with the first wick structure. 
     
     
         18 . The method for manufacturing a flat type heat pipe of  claim 13 , wherein each the notch and the protruding plate defines an arcuate cross section. 
     
     
         19 . The method for manufacturing a flat type heat pipe of  claim 13 , wherein the at least one protruding portion of the first wick structure is pressed into engagement with the second wick structure upon the flattening of the tube. 
     
     
         20 . The method for manufacturing a flat type heat pipe of  claim 13 , wherein the first wick structure preform directly or obliquely faces the second wick structure preform before the tube is flattened.