JPH11287578A - Manufacture of flat plate type heat pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain simply a flat plate type heat pipe capable of maintaining the predetermined configuration of a container even upon operation. SOLUTION: In the manufacturing method of a flat plate type heat pipe, equipped with a sealed hollow flat plate type container 1 constituted of a first member 2, on which supporting pillar units 7 are established on the inner surface of the same, and a second member 3, arranged so as to be opposed to the inside surface of the tip ends of the supporting pillar units 7, which are connected integrally, the first member 2 and the second member 3 are pressurized in the lengthwise direction of the supporting pillar units 7 and heated to connect the first member 2 to the second member 3 while connecting the tip ends of the supporting pillar unit 7 to the second member 3 integrally.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat heat pipe in which a container has a hollow flat shape, and more particularly to a method for manufacturing a flat heat pipe having a column inside a container.

[0002]

2. Description of the Related Art As is well known, a flat heat pipe forms a closed space inside a container having a hollow flat plate structure, and a condensable gas is formed in the space by removing non-condensable gas such as air. Is sealed as a working fluid. This type of heat pipe has the advantage that the surface becomes flat, so that the contact area with the object to be heat-exchanged is increased, and the heat transfer performance or heat exchange performance is improved. On the other hand,
There is a problem that the flat surface easily bends inside the container during non-operation when the internal pressure of the container becomes a vacuum pressure. Therefore, in the related art, there is a flat heat pipe having a configuration in which a support is provided between flat portions of the container that oppose each other in the thickness direction.

[0003] The method of manufacturing the flat heat pipe will be briefly described. First, a metal flat plate is pressed to form a main body having a concave cross-sectional shape having a support on the inner bottom surface. At this time, the height of the column is set to be approximately the same as or slightly larger than the depth of the main body. Next, in a state where the opening of the main body is closed with another metal flat plate material, the two are brazed to form a hollow flat plate-shaped container, and further, the container is heat piped by a generally known method. .

[0004] As described above, according to the above-described manufacturing method, since the pillar is integrally formed on one of the two members constituting the container, and the two members are brazed, the inside of the container is removed. Thus, a flat heat pipe provided with a support can be easily and efficiently manufactured.

[0005]

However, in the above-mentioned conventional manufacturing method, only the end face of the support is brought into contact with the inner surface of the flat metal material, and the movement of the opposing flat plate portions in the direction in which they are separated from each other is prevented. For example, if the internal pressure of the container becomes equal to or higher than the atmospheric pressure during the operation of the heat pipe, the inner surface of the flat metal plate is separated from the end face of the support and the outer surface of the container may be bent.
That is, the conventional manufacturing method cannot manufacture a heat pipe capable of maintaining a desired container shape during operation.

The present invention has been made in view of the above circumstances, and has as its object to provide a manufacturing method capable of easily manufacturing a flat heat pipe capable of maintaining a desired container shape even during operation. I have.

[0007]

As means for solving the above-mentioned problems, the present invention is directed to a first member having a column standing on an inner surface thereof, and an inner surface provided at a tip end of the column. In a method for manufacturing a flat heat pipe having a closed hollow flat container formed by integrally joining a second member disposed opposite to the first member, the first member and the second member are connected to the support portion. Press and heat in the length direction of
While joining the first member and the second member,
The tip of the support portion is integrally joined to the second member.

Therefore, according to the manufacturing method of the present invention, in the step of forming the container, the tip of the column can be joined to the second member, and the productivity is high.

[0009]

Next, one embodiment of the manufacturing method of the present invention will be described with reference to FIGS. First,
A cup-shaped member 2 and an upper plate 3 constituting the container 1 are prepared. More specifically, the cup-shaped member 2 corresponding to the first member of the present invention includes a bottom plate 4, a side plate 5, and a flange portion 6. The bottom plate 4 has a rectangular shape as a whole, and has eight columns 7 integrally formed with the bottom plate 4 on its upper surface. These pillars 7
As an example, it has a cylindrical shape having the same height as the bottom plate 5.
Note that the tip end surface of the support 7 is formed as a flat surface.

On four sides of the bottom plate 4, bottom plates 5 each having a flat surface extending vertically upward are formed. Note that the height of each bottom plate 5 is set smaller than the width and length of the bottom plate 4. Further, flange portions 6 extending horizontally and outward with respect to the bottom plate 4 are formed at the edges of these bottom plates 5, respectively. The flange 6
At one of the four corners, a mounting groove 8 which is depressed in a semicircular shape is formed. In addition, a thermal spray coating 9 serving as a wick is formed on a portion excluding the inner surfaces of the bottom plate 4 and the bottom plates 5 and the tip of each column 7.

On the other hand, the upper plate 3 corresponding to the second member of the present invention is a flat metal plate formed in the same size and the same shape as the flange portion 6 in a plan view. A cross-shaped holding groove 10 is formed in a portion where the tip of each pillar 7 comes into contact with the support member 7 in a state where it is assembled to the shape member 2. Further, a thermal spray coating 9 is formed on a portion of the upper plate 3 excluding the holding groove 10 and the edge.

Then, the upper plate 3 and the cup-shaped member 2 configured as described above are assembled. First, the inside of each holding groove 10 is filled with the molten filler metal 11 for brazing. Since the holding groove 10 is provided, a required amount of the brazing filler metal 11 can be provided without being raised from the surface of the upper plate 3. In addition, the same filler metal for brazing 1
1 is applied to the upper surface of the flange portion 6 in FIG. Furthermore,
A small diameter pipe 12 serving as an injection nozzle is placed in a state fitted in the mounting groove 8, and a brazing filler metal 11 is melted between them and in the upper surface of the small diameter pipe 12 in a range fitted in the mounting groove 8. Is applied.

After the brazing filler metal 11 has been solidified, the cup-shaped member 2 and the upper plate 3 are temporarily set in a state where the opening formed by the four bottom plates 5 is closed by the upper plate 3. Assemble. The surface of the upper plate 3 where the holding groove 10 is formed is
Turn to the bottom plate 4 side. That is, as shown in FIG. 2, between the upper surface of the flange portion 6 and the lower surface of the upper plate 3, between the upper surface of the column 7 and the lower surface of the upper plate 3, and between the outer peripheral surface of the small diameter pipe 12 and the upper plate 3. Is provided between the lower surface and the mounting groove 8.

Then, the three-unit unit 13 temporarily assembled as described above is brazed. That is, the unit 24 is, for example, a burner (see FIG. 4) in a state in which the respective columns 7 and the upper plate 3 are pressed by the appropriate jigs 14 arranged on the outer surface side of the upper plate 3 and the outer side of the bottom plate 4 in the approaching direction. (Not shown). As a result, the mating surface between the flange portion 6 and the upper plate 3 is brazed and integrally joined. In addition, the front end of the column 7 and the mating surface of the upper plate 3 are brazed and integrally joined. Further, the small-diameter pipe 12 is fixed to the flange 6 and the lower surface of the upper plate 3 by brazing. That is, a hollow flat container 1 having an injection nozzle is completed.

Further, the container 1 is formed into a heat pipe. As the means, a conventionally known means such as a heating purge method, a vacuum pump method or a gas liquefaction method can be employed.

As described above, according to the manufacturing method of this embodiment, in the step of forming the container 1, that is, in the step of brazing the flange portion 6 and the upper plate 3, each column 7 is connected to the inner surface of the upper plate 3. Therefore, the flat heat pipe 15 in which the tips of the plurality of columns 7 are joined to the inner surface of the upper plate 3 can be manufactured in a simple and small number of steps. That is, according to the above manufacturing method, mass production is possible.

Next, the flat heat pipe 15 manufactured by the above manufacturing method will be described with reference to FIG. The flat heat pipe 15 includes a cup-shaped member 2 having an opening width larger than a depth, and the cup-shaped member 2.
The hollow plate-shaped container 1 is constituted by the upper plate 3 assembled so as to close the opening portion of the container 1. A working fluid (not shown) is sealed inside the container 1 in a state where non-condensable gas is degassed. In addition, a small-diameter pipe 1 serving as an injection nozzle is partially provided in four corners of the container 1.
2 are installed.

On the inner bottom surface (bottom plate 4) of the cup-shaped member 2,
Eight cylindrical pillars 7 formed integrally with the inner bottom surface are provided. The distal ends of these columns 7 are integrally joined to the portion of the inner surface of the upper plate 3 where the holding grooves 10 are formed by brazing. In other words, portions of the upper plate 3 and the bottom plate 4 that are separated from the edges are substantially integrally connected by the columns 7.

A thermal spray coating 9 as a wick is formed on the entire inner surface of the container 1 including the surface of each column 7. The thermal spray coating 9 has a porous structure having pores between thermal spray particles bonded to each other, and generates a large capillary pressure. The mating surface between the upper plate 3 and the flange 6 is sealed by brazing.

According to the flat heat pipe 15, for example, the CPU to be cooled is arranged on the outer surface of the bottom plate 4 in close contact with the heat sink (both not shown) on the outer surface of the upper plate 3. It is provided inside a personal computer case (not shown) in a posture attached to the PC.

Therefore, the flat heat pipe 15
Also, when the working fluid is evaporated by heating by the CPU, the internal pressure of the container 1 increases, and a force acts in a direction to separate the bottom plate 4 and the top plate 3 from each other. However,
The upper end of each of the eight columns 7 is joined to the inner surface of the upper plate 3, and the central portions of the bottom plate 4 and the upper plate 3 in the plane direction are connected to each other. Does not deform such that it expands in an arc shape. That is,
The container 1 can be maintained in a desired shape. Therefore, heat transfer between the container 1 and the heat sink and the CPU is performed favorably, and as a result, overheating of the CPU can be reliably prevented.

Since the upper plate 3 and the bottom plate 4 are supported from the inside by the metal columns 7, there is no deformation such that these portions bend inside the container 1 even during non-operation.

Next, another embodiment of the manufacturing method of the present invention will be described with reference to FIG. In addition, in the example shown here, the step of joining the cup-shaped member 2 and the upper plate 3 and the column 7 and the upper plate 3 will be mainly described, and detailed description of the same steps as those in the above specific example will be omitted.

First, a melted brazing filler metal 11 is applied to the flange 6 of the cup-shaped member 2 and the upper surface of the small-diameter pipe 12 in a range fitted in the mounting groove 8. In this specific example, the holding groove 10 in the above specific example is not formed on the upper plate 3, and the brazing filler metal 11 is not applied to the upper plate 3.

Next, the cup-shaped member 2 and the upper plate 3 are temporarily assembled while the opening formed by the four bottom plates 5 is closed by the upper plate 3. That is, as shown in FIG. 4, a solid-phase brazing filler metal 11 is interposed between the upper surface of the flange portion 6 and the lower surface of the upper plate 3, and each of the pillars is positioned with respect to the lower surface of the upper plate 3. 7 are brought into contact with each other so that the front end faces are in contact with each other. A solid-phase soldering filler material 11 is also provided between the outer peripheral surface of the small-diameter tube 12 and the lower surface of the upper plate 3 and the mounting groove 8.

Then, the temporarily assembled unit 24 is subjected to brazing and diffusion bonding. That is, the unit 24 is, for example, a burner (see FIG. 4) in a state where the respective columns 7 and the upper plate 3 are pressed by the appropriate jigs 14 arranged on the outer surface side of the upper plate 3 and the outer side of the bottom plate 4 in the approaching direction. Not shown)
Heat with. As a result, the mating surface between the flange portion 6 and the upper plate 3 is brazed and integrally joined. Further, the small diameter pipe 12, the flange portion 6 and the upper plate 3 are brazed and integrally joined. Further, the tip of the column 7 and the contact surface between the upper plate 3 are diffusion-bonded and integrally bonded.

Thus, a hollow flat container 1 having an injection nozzle is completed. Further, the container 1 is formed into a heat pipe, and the plate-shaped heat pipe 15 is completed by performing an inspection process according to a usual manner.

According to the above-described manufacturing method, the step of forming the holding groove 10 in the upper plate 3 and the step of applying the brazing filler metal 11 to the holding groove 10 are omitted. Productivity can be further improved.

Next, still another embodiment of the manufacturing method of the present invention will be described with reference to FIG. This specific example is an example in which projection welding is adopted. First, projections 16 having a smaller surface area than, for example, the surface area of those members are formed on the front end surface of each support 7 and the upper surface of the flange 6. As an example, these projections 16 are made of the same material as the cup-shaped member 2. And the protrusion 1
The upper plate 3 and the cup-shaped member 2 are temporarily assembled in a posture such that the opening of the cup-shaped member 2 provided with 6 is closed by the upper plate 3.

Further, the unit 24 is pressurized in a direction in which the respective columns 7 and the upper plate 3 approach each other by an appropriate jig 14 disposed on the outer surface side of the upper plate 3 and the outer side of the bottom plate 4. An electric current flows through the joint between the support plate 7 and the flange 6 on the upper surface of the upper plate 3 by means of a resistance welding machine not used. Then
Since the resistance heat is concentrated on each of the projections 16, the projections 16 of the unit 24 are preferentially melted. As a result, the above-mentioned joint portions are integrally joined. That is, the container 1 is formed in which the front end of each column 7 is welded to the upper plate 3 and the flange 6 is welded to the upper plate 3.

Therefore, according to the specific example shown in FIG.
The container 1 in which the brazing filler metal 11 is not interposed between the upper plate 3 and the column 7 and between the upper plate 3 and the flange portion 6 can be manufactured.

In each of the above specific examples, a container constituted by a cup-shaped member and an upper plate has been exemplified. However, the present invention is not limited to the above specific example. Any shape may be used as long as the shape is a hollow flat plate, and thus, for example, a configuration in which two cup-shaped members are joined to each other may be used. Further, in the above-described specific example, the column integrally formed on the cup-shaped member is illustrated. However, the column may be formed integrally with the upper plate, or may be configured separately from the cup-shaped member and the upper plate. Can also.

Further, in the above specific example, brazing, diffusion bonding and projection welding are exemplified as means for joining the support and the upper plate. However, the present invention is not limited to the above specific example. Means such as pressure welding may be employed. In the above specific example, the thermal spray coating is given as the wick. However, as another example of the wick, a wick having a porous structure formed by sintering metal particles may be employed.

[0034]

As described above, according to the present invention, the first member and the second member are pressed and heated in the length direction of the column, and the first member and the second member are separated from each other. This is a manufacturing method in which the tip of the support portion is integrally joined to the second member, that is, the tip of the support portion can be joined to the inner surface of the container in the step of forming the container. A flat heat pipe capable of maintaining the desired container shape can be easily manufactured.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a step of heating a unit while applying pressure.

FIG. 2 is a sectional view showing an assembled state of an upper plate and a cup-shaped member.

FIG. 3 is a schematic view showing a flat heat pipe with a part cut away.

FIG. 4 is a schematic diagram showing another specific example of the present invention.

FIG. 5 is a schematic view showing still another specific example of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Container, 2 ... Cup-shaped member, 3 ... Upper plate, 4
... Bottom plate, 6 ... Flange part, 7 ... Prop, 10 ... Holding groove, 11 ... Soldering filler metal, 13 ... Unit, 1
4: Jig, 15: Flat heat pipe.

Continued on the front page (72) Inventor Yuji Saito 1-5-1, Kiba, Koto-ku, Tokyo Inside Fujikura Co., Ltd. (72) Inventor Tan Nuen 1-5-1, Kiba, Koto-ku, Tokyo Inside Fujikura Co., Ltd.

Claims (1)

[Claims] 1. A first member having a pillar portion erected on an inner surface thereof;
In a method for manufacturing a flat heat pipe including a closed hollow flat container formed by integrally joining a second member disposed opposite to the inner surface to a distal end side of the support portion, the first member and The second member is pressed and heated in the length direction of the support portion and heated to join the first member and the second member, and the tip of the support portion is integrated with the second member. A method for producing a flat heat pipe, which is characterized by joining.