JP2000230790A - Flat type heat pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flat type heat pipe wherein a heat receiving plate and a radiation plate can be easily bonded to each other and a wick can be easily mounted to the plates. SOLUTION: In the heat pipe, a plurality of wire mesh bodies 3 are arranged between a heat receiving plate 1 and a radiation plate 2 so as to be spaced apart from one another by predetermined intervals. An adhesive is impregnated into each body 3 to form an interval holding spacer between the plate 1 and the plate 2. The plate 1 can be easily bonded to the plate 2 so as to be spaced from each other trough the wire mesh bodies 3 each of which is impregnated with adhesives, and a wick can be easily disposed in fluid passages for working liquid formed between regularly spaced apart bodies 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a personal computer CPU.
The present invention relates to a structure of a flat heat pipe suitable for cooling a heat-generating component in an electronic device housing such as a multi-chip module incorporating a semiconductor device.

[0002]

2. Description of the Related Art Generally, a heat pipe is used as a cooling body in an electronic device by attaching a heat receiving plate and a heat radiating plate to a conventional tubular heat pipe, and routing the heat pipe in accordance with the position of the heat generating portion and the heat radiating portion. It was a target. In recent years, the heat generation density has increased with the increase in the density of electronic devices, and flat heat pipes having a larger heat transport amount have been used in many cases. In addition to the increased heat transport, flat heat pipes can respond even if the position of the heating element changes in the flat end surface area of the flat heat pipe, increasing the degree of freedom in design within the housing of electronic equipment. There are advantages.

As a structure of a flat heat pipe, for example, as shown in FIGS. 9 and 10, an aluminum extruded material 21 having a honeycomb structure having a rectangular cross section is used, and a hydraulic fluid is supplied to a large number of flow paths 24 having a honeycomb structure. There is a type in which the open end is sealed with a sealing member 23 after injection. 25 in the figure
Is a wick, which promotes the circulation of hydraulic fluid by the action of its own capillary.

[0004]

However, the above-mentioned prior art has the following problems. In the flat type heat pipe using the extruded material 21, each of the flow paths 24 is narrow, and it is difficult to insert the wick 25 into an appropriate position of each of the flow paths 24. . In addition, since extrusion molding is used, the material is limited. For example, there is a problem in that the working fluid is limited to fluorocarbon, hydrocarbon, and the like in relation to the material by aluminum or the like. SUMMARY OF THE INVENTION An object of the present invention is to provide a flat heat pipe capable of easily adhering a heat receiving plate and a heat radiating plate and facilitating mounting of a wick in order to solve the above-mentioned problems.

[0005]

A flat heat pipe according to the present invention comprises a plurality of wire meshes arranged at a predetermined interval between a heat receiving plate and a heat radiating plate, and the wire meshes are impregnated with an adhesive. The two flat plate spacing spacers formed are provided. According to such a heat pipe, the heat receiving plate and the heat radiating plate can be easily adhered to each other through the wire mesh body at intervals according to the size of the wire mesh itself by the adhesive impregnated into the plurality of wire mesh bodies, and at a predetermined interval. The wick can be easily arranged in the flow path of the hydraulic fluid formed between the metal mesh bodies arranged apart. In addition, it is desirable to leave a portion that is not impregnated with the adhesive in the peripheral portion of the wire netting in that the wire netting in that portion acts as a wick in the thickness direction.

The wire mesh is not particularly limited as long as it has a strength capable of forming a spacer, but is preferably made of a copper-based metal material having a high thermal conductivity or a metal such as stainless steel. Wire mesh is preferred. The size of the mesh of the wire mesh is not particularly limited as long as the mesh is impregnated with the adhesive and does not flow out of the wire mesh. 50
Mesh or 300 mesh). The material of the adhesive is not limited as long as the adhesive is held in the space between the spacer and the wick and has a viscosity that does not flow out of the wire netting, but an epoxy-based or urethane-based adhesive is particularly desirable.

In the flat heat pipe according to the present invention, a plurality of sintered bodies having a mesh-like gap are arranged at predetermined intervals between a heat receiving plate and a heat radiating plate, and these sintered bodies are impregnated with an adhesive. The two flat plate spacing spacers formed are provided. According to such a heat pipe, the heat receiving plate and the heat radiating plate can be easily bonded via the sintered body itself at intervals according to the size of the sintered body itself by the adhesive impregnated in the sintered body, and The wick can be easily arranged in the working fluid flow path formed between the sintered bodies arranged at a predetermined interval.

The above-mentioned sintered body has a strength capable of forming a spacer, and is preferably made of a metal having excellent heat conductivity. In addition, the size of the mesh-shaped gap is also particularly so long as it is impregnated with the adhesive and does not flow out of the sintered body,
Although the number is not limited, the average gap is 0.0
It is desirable that the number of gaps is 5 mm to 0.1 mm and the number of gaps is as large as possible as long as strength can be maintained. The material of the adhesive is not limited as long as the adhesive has a viscosity that does not flow out of the sintered body, but the above-described example of the adhesive is preferable.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a first embodiment of a flat heat pipe according to the present invention will be described with reference to FIGS. The substrates 1 and 2 are metal thin plates, and a spacer 3 is disposed on the substrate 1 via a sheet-like wire mesh wick 5. In this example, a coarse and thick wire mesh is used as the spacer 3. The spacers 3 are arranged at appropriate intervals inside the effective flow path. Reference numeral 4 denotes a cured layer of the adhesive inside the spacer 3. The external seal portion 6 is arranged on the outer periphery of the substrates 1 and 2 except for a portion serving as an injection port (not shown) of the hydraulic fluid. A working fluid is injected into a space surrounded by the spacer 3 and the external seal portion 6 between the substrates 1 and 2, and the above-described injection port, not shown, is sealed with a sealing agent.

[0010] The size of such a flat heat pipe is 200 mm and 50 mm in the longitudinal and transverse directions, and 1 mm in the height direction. The thickness dimensions of the substrates 1 and 2 are 0.3 mm, the thickness dimension of the spacer 3 is 0.3 mm, and the length * width dimension of the cross section of the spacer 3 is 3 mm * 3 mm. 70 mesh was used as the wire mesh of the spacer 3.
As the adhesive, an epoxy-based adhesive having a viscosity of 90000 cps is used, and the diameter of the cured layer 4 of the adhesive is about 2 mm. As the wire mesh of the wick 5, a 300-mesh, 0.1 mm-thick phosphor bronze wire mesh was used. A copper plate having a thickness of 0.3 mm was used as the substrates 1 and 2, and water was used as a working fluid. In the flat heat pipe described above, the portion of the spacer 3 which is not filled with the adhesive has a vertical capillary action on the working fluid and also acts as a wick, so that the wick having a horizontal capillary action is provided. 5, the cooling performance was improved.

Next, a method for manufacturing the above-mentioned flat heat pipe will be described. A wick 5 is laid on the substrate 1, the spacer 3 is placed thereon, and an adhesive having an appropriate viscosity is applied from above the spacer 3. Thereafter, by pressing the substrate 2 from above, the adhesive penetrates to the substrate 1 through the wick 5 and is held in the space of the spacer 3 to bond the substrates 1 and 2 together. The arrangement of the spacers 3 is determined by calculating the required pitch from the condition that the pressure withstands when the heat pipe is used. Finally, the working fluid is injected from the injection port to seal the injection port.

A second embodiment of the flat heat pipe according to the present invention will be described with reference to FIGS. In the flat heat pipe according to this embodiment, the members of the spacer are changed as compared with the first embodiment, and the same members as those shown in FIGS. Omitted. A porous spacer 13 is arranged on a substrate 1 via a sheet-like wire mesh wick 5. The spacers 13 are arranged at appropriate intervals inside the effective flow path. Reference numeral 14 denotes a cured layer of the adhesive inside the spacer 13. The working fluid is injected into a space surrounded by the spacer 13 between the substrates 1 and 2 and the external seal portion 6, and the above-described injection port, not shown, is sealed with a sealing agent.

The spacer 13 is made of a sintered body of a bronze material, has a thickness of 0.3 mm, and a horizontal cross section of the spacer 13 has a length * width of 3 mm * 3 mm. Spacer 13
As a sintered body, a bronze spherical lump (having a diameter of about 0.1 m
m) was used. The average gap is about 0.05 mm. As the adhesive, the same epoxy resin as that of the first embodiment is used, and the diameter of the layer 14 where the adhesive is cured in the pacer 13 is about 2 mm.

In the flat heat pipe of each of the above embodiments, the material of each member can be selected from the condition that it is stable with respect to the working fluid. The substrates 1 and 2 are generally made of copper, aluminum or the like having good thermal conductivity. The spacers 3, 13 and the wick 5 can be selected from a copper-based material, stainless steel, or the like in consideration of good thermal conductivity and the condition of maintaining strength against pressure during operation. As the adhesive, an epoxy-based adhesive or the like can be used, but a material having a viscosity and a curing time that can be bonded to the substrates 1 and 2 while being held in the gaps of the used wick 5 and the spacers 3 and 13 and not flowing out to the surroundings can be used. do it. The outer peripheral seal part 6 leaves an opening partly,
A predetermined amount of hydraulic fluid is injected from the opening. The hydraulic fluid is
Water, perfluorocarbon, ethanol and the like are used.

[0015]

As described in detail above, in the flat heat pipe of the present invention, a plurality of wire meshes are arranged at a predetermined interval between a heat receiving plate and a heat radiating plate, and an adhesive is provided in these wire meshes. And two plate-spacing spacers formed by impregnation. According to such a heat pipe, the heat receiving plate and the heat radiating plate can be easily adhered to each other through the wire mesh body at intervals according to the size of the wire mesh body by the adhesive impregnated in the wire mesh body, and The wick can be easily arranged in the flow path of the working fluid formed between the metal nets arranged at intervals.

[Brief description of the drawings]

FIG. 1 is a perspective view of a flat heat pipe according to a first embodiment of the present invention.

FIG. 2 is an enlarged sectional view taken along line 2-2 of the flat heat pipe shown in FIG.

FIG. 3 is an enlarged plan view of a main part of the flat heat pipe shown in FIG. 1;

FIG. 4 is a view showing a main part of the flat heat pipe shown in FIG.
It is a line sectional view.

FIG. 5 is a perspective view of a flat heat pipe according to a second embodiment of the present invention.

FIG. 6 is an enlarged sectional view taken along line 6-6 of the flat heat pipe shown in FIG.

7 is an enlarged plan view of a main part of the flat heat pipe shown in FIG. 5;

FIG. 8-8 of the essential part of the flat heat pipe shown in FIG. 7;
It is a line sectional view.

FIG. 9 is a perspective view of a heat pipe manufactured by a conventional extrusion method.

FIG. 10 is an enlarged sectional view taken along line 10-10 of the heat pipe shown in FIG. 7;

[Explanation of symbols]

 1, 2 substrate 3, 13 spacer 4, 14 layer with cured adhesive 5 wick

Claims (2)

[Claims] 1. A two-plate spacing maintaining spacer formed by arranging a plurality of wire meshes at a predetermined interval between a heat receiving plate and a heat radiating plate, and impregnating the wire mesh with an adhesive. A flat type heat pipe comprising: 2. A method according to claim 1, wherein a plurality of sintered bodies having a mesh-like gap are arranged at predetermined intervals between the heat receiving plate and the heat radiating plate, and the sintered bodies are formed by impregnating an adhesive. A flat heat pipe comprising a flat plate spacing spacer.