Patent ID: 8496161
Filing Date: 2013-07-30
Classification: B23K,H01L

Abstract:
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 comprising obtaining heat pipe components comprising pipes being hollow, and each pipe having an inner diameter, an outer diameter, a lower end and an upper end, bases, each base has a hole that is larger than the outer diameter of the pipe and has an upper surface, covers, each cover including a central through-hole and being smaller than the inner diameter of 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 comprising steps of: (B1) assembling primary components of the heat pipe comprising mounting the cover on the upper end of the pipe, mounting the lower end of the pipe on the hole of the base and mounting the small pipe in the central through-hole; and (B2) putting copper-silver alloy filler rings respectively at joints between primary components that 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 N2, NH4 and H2 in a ratio of 2:1:1 into a steel liner of a brazing furnace at the heating elements; (D) turning on a multi-stage brazing heater and cooler causing an 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 the heat pipe assemblies on a conveyor comprising placing the heat pipe assemblies on the conveyor sliding on an input bracket assembly to be carried into and through the brazing furnace; (F) brazing the heat pipe assemblies to form heat pipes comprising 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; (G) cooling the heat pipes comprising moving the brazed heat pipes through the cooling element and onto an output bracket assembly after the heat pipes are cooled to approximately 150° C.; and (H) removing the heat pipes from the conveyor comprising 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 copper and brazed by the multiple copper-silver alloy filler rings without flux and the pipe has a diameter in range from 20 millimeters to 100 millimeters, the heat pipe is reduced in 400° C. for removing oxide.