Method for manufacturing a plate-type heat pipe

Abstract

A method for manufacturing a plate-type heat pipe includes filling a cavity of a mold with a core, and filling first and second metal powders into the injection systems of a double-mode injection molder with opposite injection directions. The first and second metal powders are injected into the cavity, and the first metal powder adheres to the core and the second metal powder adheres to the first metal powder. The resulting green piece is removed from the mold and the core removed therefrom by thermal or chemical reaction, resulting in a chamber in the green piece. The green piece is heated to obtain a sintered product with a tight outer wall constituting the sintered second metal powder and a wick structure constituting the sintered first powder. Finally a working fluid is injected into the chamber, and the sintered workpiece is evacuated by vacuum and sealed.

1 . A method for manufacturing a plate-type heat pipe comprising:
 depositing a core into a cavity of a mold, wherein the cavity is filled;   filling first and second metal powders respectively into two injection systems with opposite directions of a double-mode injection molder;   using the double-mode injection molder to inject the first and second metal powders into the cavity of the mold, wherein the first metal powder securely adheres to the core and the second metal powder securely adheres to the first metal powder, thereby forming a green piece;   removing the core from the green piece to define a chamber therein;   heating the green piece to obtain a sintered workpiece;   injecting a working fluid into the chamber;   evacuating by vacuum the sintered workpiece; and   sealing an opening end of the sintered workpiece.   
     
     
         2 . The method for manufacturing a plate-type heat pipe as claimed in  claim 1 , wherein the second metal powder sintered to form a tight outer wall on the sintered workpiece. 
     
     
         3 . The method for manufacturing a plate-type heat pipe as in  claim 2 , wherein the first metal powder is sintered to form a continuous wick structure having a plurality of pores and lining an inner wall of the outer wall. 
     
     
         4 . The method for manufacturing a plate-type heat pipe as in  claim 3 , wherein the chamber is located at a central portion of the wick structure. 
     
     
         5 . The method for manufacturing a plate-type heat pipe as in  claim 3 , wherein a plurality of spaced supporting portions is formed in the chamber of the plate-type heat pipe. 
     
     
         6 . The method for manufacturing a plate-type heat pipe as in  claim 5 , wherein the supporting portions connect with top and bottom ends of the wick structure of the plate-type heat pipe. 
     
     
         7 . The method for manufacturing a plate-type heat pipe as in  claim 6 , wherein the supporting portions comprise a plurality of pores communicating with pores of the wick structure. 
     
     
         8 . The method for manufacturing a plate-type heat pipe as in  claim 5 , wherein the core comprises a plurality of holes and a part of first metal powder fills the holes of the core to form the supporting portions. 
     
     
         9 . The method for manufacturing a plate-type heat pipe as in  claim 1 , wherein the first metal powder comprises a particle size exceeding that of the second metal powder. 
     
     
         10 . The method for manufacturing a plate-type heat pipe as in  claim 1 , wherein the core is a high polymer material or waxy material. 
     
     
         11 . The method for manufacturing a plate-type heat pipe as in  claim 1 , wherein the core is removed from the green piece by thermal or chemical reaction. 
     
     
         12 . A method for manufacturing a plate-type heat pipe comprising:
 providing a core formed by a material which is releasable by one of thermal reaction and chemical reaction;   adhering a first powder to a surface of the core;   adhering a second powder to a surface of the first powder, where the second powder has a particle size smaller than that of the first powder;   removing the core from the first powder so that a chamber is surrounded by the first powder;   heating the first and second powders to a temperature that the second powder is sintered to be a tight outer wall and the first powder is sintered to be a wick structure in the tight outer wall;   injecting working liquid into the chamber; and   vacuuming and sealing the chamber.   
     
     
         13 . The method as claimed in  claim 12 , where the first powder is adhered to the core and the second powder is adhered to the first powder by using a double-mode injection molder. 
     
     
         14 . The method as claimed in  claim 12 , wherein the core defines a plurality of holes therethrough and the first powder fills in the holes. 
     
     
         15 . The method as claimed in  claim 12 , wherein the first powder has a particle size of 50 μm to 150 μm, and the second powder has a particle size of 10 μm to 20 μm. 
     
     
         16 . The method as claimed in  claim 12 , wherein the core is made of one of a polymer material and a waxy material. 
     
     
         17 . The method as claimed in  claim 12 , wherein the first and second powders are metal powders.