Device and method for brazing a heat pipe

Abstract

The present invention relates to a device and method for brazing a heat pipe assembly with copper-silver alloy filler rings to improve heat dissipation efficiency of a heat pipe. The device comprises a brazing furnace and a conveyor. The brazing furnace comprises an open ended passage with a multi-stage brazing heater and cooler. The conveyor comprises an input bracket assembly, an output bracket assembly and a steel mesh belt. The method comprises steps of (A) providing multiple heat pipe components, (B) assembling the heat pipe components to form heat pipe assemblies, (C) injecting mixed gas, (D) turning on the multi-stage brazing heater and cooler, (E) placing the heat pipe assemblies on the conveyor, (F) brazing the heat pipe assemblies to form heat pipes, (G) cooling the heat pipes and (H) removing the heat pipes from the conveyor.

1 . A method for brazing heat pipe components having a pipe, a base, a cover, a small pipe and multiple copper-silver alloy filler rings, the method comprising steps of
 (A) providing multiple heat pipe components comprises obtaining heat pipe components comprising pipes being hollow, and each pipe having a lower end and an upper end, bases, each base is larger than the pipe and has an upper surface, covers, each cover including a central through-hole and smaller than the pipe, small pipes corresponding respectively to the central through-holes and copper-silver alloy filler rings;   (B) assembling the heat pipe components to form heat pipe assemblies comprises steps of
 (B1) assembling primary components of the heat pipe comprises mounting the lower end of the pipe on the upper surface of the base, mounting the cover on the upper end of the pipe and mounting the small pipe in the central through-hole; and 
 (B2) mounting copper-silver alloy filler rings respectively at joints between primary components will cause the copper-silver alloy filler rings to fill and close gaps between primary components when brazed and melted; 
   (C) injecting mixed gas comprising injecting N 2 , NH 4  and H 2  in a ratio of 2:1:1 into the steel liner of the brazing furnace at the heating elements;   (D) turning on the multi-stage brazing heater and cooler causing the initial stage to heat to approximately 220° C. and burn the mixed gas to evacuate most oxygen in the brazing furnace and remove any impurities from inside the steel liner to obviate oxidation of the heat pipe assemblies in the brazing furnace;   (E) placing heat pipe assemblies on the conveyor comprises placing the heat pipe assemblies on the conveyor sliding on the input bracket assembly to be carried into and through the brazing furnace;   (F) brazing the heat pipe assemblies to form heat pipes comprises moving the heat pipe assemblies through the multi-stage heating elements, heating the heat pipe assemblies to 780° C. and melting the copper-silver alloy filler rings to fill any gaps without oxygen;   (G) cooling the heat pipes comprises moving the brazed heat pipes through the cooling element and onto the output bracket assembly after the heat pipes are cooled to approximately 150° C.; and   (H) removing the heat pipes from the conveyor comprises removing the heat pipes from the output bracket assembly after the molten copper-silver alloy filler rings solidify, wherein   the pipe, the base, the cover and the small pipe are made of same material and brazed by the multiple copper-silver alloy filler rings without flux and the pipe has a diameter greater than 20 mini-meters.   
   
   
       2 . The method as claimed in  claim 1 , wherein the upper surface of each base has a recess corresponding to the pipe. 
   
   
       3 . The method as claimed in  claim 1 , wherein removing the heat pipes from the output bracket assembly is performed robotically. 
   
   
       4 . The method as claimed in  claim 1 , wherein the pipe, the base, the cover and the small pipe are made of copper.