TWI260385B - Sintered heat pipe and method for manufacturing the same - Google Patents

Abstract

A sintered heat pipe includes a tube and a capillary structure formed on the inner wall of the tube. The capillary structure formed by sintered powder includes at least three sections arranged in axis of the tube and being different in size of the powder. Method for manufacture of the sintered heat pipe includes the following steps: (1) providing the tube, and inserting a rigid mandril into the tube; (2) filling at least three types of powder into a space formed between an inner wall of the tube and the rigid mandril in turn for forming the at least three sections of the capillary structure, the size of the three types of powder increasing sequentially; (3) sintering the powder, and then drawing out the rigid mandril; (4) filling working liquid into the tube, and then vacuumizing and sealing the tube.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat transfer device and a method of manufacturing the same, and more particularly to a sintered heat pipe used in the field of electronics and a method of manufacturing the same. [Prior Art]

Before I, the heat pipe has a fast heat transfer rate and is widely used in the field of electronic component heat dissipation. The commonly used heat pipe comprises a sealed tubular casing having a constant vacuum degree, and in the casing = a single capillary structure without sintering and filled with a proper amount of working liquid, the heat is wide, and the evaporation end is another - The end is the condensation end. When the fresh evaporation end is scaled, the working liquid is vaporized, and the steam flows to the condensation end to release heat under a slight pressure difference, and then condenses into a liquid, and the liquid is returned to the evaporation end under the capillary force of the capillary structure, so that the heat is evaporated by the heat pipe. The end is quickly transferred to the condensation end. However, the working performance of the heat pipe is affected by the capillary pressure difference and the reflux resistance, which are caused by the capillary pore size of the capillary structure. When the capillary pores are small, the capillary pressure difference is large. Driving the condensed liquid into the capillary = in the structure ^ reflux to the evaporation end, but on the other hand, the reduction of the capillary pores makes the working fluid reflux = friction and viscous force increase, that is, the working fluid reflux resistance increases, resulting in the working fluid reflux speed Slow, easy to make the heat pipe dry burning phenomenon at the evaporation end, and when the capillary pores are large, the work, the body receives less backflow resistance, of course, the capillary pressure of the condensed liquid is sucked into the capillary structure, and the working fluid return flow is reduced. Further, the heat pipe may be dry-fired at the evaporation end. SUMMARY OF THE INVENTION An object of the present invention is to provide a heat pipe having a large capillary pressure difference, a reflux resistance, and a method of manufacturing the same. Heart, ° type The sintered heat pipe of the present invention comprises a casing and a capillary structure disposed on the inner wall of the casing, the capillary structure being sintered by at least three-stage structure in which powders having different particle sizes from each other are sintered. The manufacturing method of the sintered heat pipe of the present invention comprises the following steps: 1) providing a casing into which a hard mandrel is inserted; 2) sequentially filling at least two of increasing diameters in the gap between the casing and the hard mandrel Section powder; 3) Sintering the powder in the shell, and then withdrawing the hard core rod; $ filling the working liquid into the casing and vacuum-sealing. , 6 1260385 Compared with the prior art, the capillary structure of the sintered heat pipe of the present invention is formed by different particle diameters, thereby producing a capillary structure having different capillary pores, wherein the smaller hair 'flow, = structure is produced The large capillary pressure difference drives the condensed liquid back inside the capillary structure: the capillary structure of the larger capillary pores exerts a stronger force on the returning working fluid, and the working fluid returns rapidly.乂 乂 口 口 口 【 【 【 【 【 【 【 【 【 【 【 【 【 【 【 【 【 【 【 【 【 【 【 【 【 【 【 【 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 11 , copper and aluminum two steel / sheet geometry. The capillary structure consists of a powder segment 12, a second capillary structure segment 13 and a third capillary structure segment u:; a working alcohol, as a liquid. The working fluid is selected from a liquid having a low boiling point chemical stability, such as B. 2 to 6 In the above, the sintered heat pipe can be inserted into a hard mandrel 20 through the following body 11 body 11, and the hard core 'rod 2 〇 壳 、 、 、, line; 2) to the casing 11 and The gap between the hard core rods 20 is sequentially set to three increments of copper powder; 3) at 1 coffee. . The copper core rod 20 in the casing η is sintered to the left and right; 4) the working liquid (not shown) is filled into the casing 11, and the furnace is sealed to form the sintered heat pipe of the present invention. , and the eight bronzes will not be mixed into the copper powder filled in, which is easy to fill and process. ΜΛ ^ ^ 于 于 于 于 于 于 于 于 于 于 于 于 于 于 于 于 于 于 烧结 烧结 烧结 烧结 烧结 烧结 烧结 烧结 烧结 烧结 烧结 烧结 烧结 烧结 烧结 烧结 烧结 烧结 烧结 烧结 烧结 烧结 烧结 烧结 烧结 烧结 烧结 烧结 烧结The particle size of the powder can be selected according to actual needs. He uses it forever. Compared with the conventional heat pipe, the capillary structure of the sintered heat pipe of the present invention has a gradient in the axial direction, wherein the capillary structure of the smaller capillary pores has a large fraction, which facilitates the condensed liquid to enter the capillary knot. In the capillary structure, ^, 广广,,, capillary structure produces a second-to-return working liquid. For example, the end of the third capillary structure section 14 of the heat pipe is taken as the 'end, = the capillary structure lx 12 is used as the condensation end, that is, the fresh capillary hole P« from the evaporation end to the cold is reduced, in the cold-aged-capillary section 12 仏 较 : 】 】 】 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 12 , the return flow resistance of the working liquid decreases, and the reflux speed increases the error of the 乂" 'to the end of the hair to participate in the evaporation cycle again; for example, the first leg of the heat pipe is from the end of the ^, the end of the third capillary structure 14 At the condensing end, the capillary pores of the iiirt structure are increased. At the condensing end, due to the third condensing station end, the drums are cold, and the cold body is less squeaky and smoothly flows back to the steaming table. Two-action °: force: fine-acting condensed liquid is more - capillary 3 offering 19 again. In addition, the sintered heat pipe of the present invention has a smaller capillary pore size, so that a larger surface area is thermally exchanged with the outside world. Fine = fine; above = ίί (4) material county, New Zealand materials, please do. However, God's equivalent modification or change All should be ==Special j [Simplified description of the drawing] = one = is a schematic cross-sectional view of the sintered heat pipe of the present invention along its axis. It is a flow chart of the sintered fresh manufacturing of the present invention. L main 7L symbol description] Capillary structure section 13 Hard mandrel 20 The first capillary structure section The second capillary structure section is a schematic diagram of the present invention.

Claims (1)

1260385, X. Patent Application Range: ^ 1. A sintered heat pipe comprising a casing and a capillary structure disposed on the inner wall of the casing, the improvement being that the capillary structure is sintered by powders having different particle sizes from each other. Into a three-stage structure. 2. The sintered heat pipe according to claim 1, wherein the powder is increased or decreased in particle size along the axial direction of the casing. 3. A method of manufacturing a sintered heat pipe according to claim 1, comprising the steps of: 1) providing a housing into which a hard core rod is inserted; 2) facing the housing and the hard core rod The gap is filled with at least three stages of powder having an increasing particle diameter; 3) sintering the powder in the casing, and then extracting the hard core rod; 4) filling the working liquid into the casing, and vacuuming the seal. 4. The method for producing a sintered heat pipe according to claim 3, wherein the powder is a metal powder or a ceramic powder. 5. The method of manufacturing a sintered heat pipe according to claim 4, wherein the metal powder is copper powder or copper tin alloy powder or aluminum powder.