JP2004037074A - Plate type heat pipe and cooling structure using it - Google Patents

Abstract

An object of the present invention is to realize a plate-type heat pipe having a small number of members and excellent in manufacturing cost.
A plate-type heat pipe provided with a box-shaped container having a plate-shaped member and one or two opposing surfaces of a thickness portion thereof are joined and assembled, wherein a component to be cooled is directly attached to the container. Alternatively, a plate-shaped heat pipe in which a convex portion to be indirectly contacted is formed, and a heat conductive internal block is arranged in a portion corresponding to the convex portion in a hollow portion formed by the container.
[Selection diagram] Fig. 1

Description

{Circle over (1)} The present invention relates to a plate-shaped heat pipe suitable for cooling components that require cooling, such as a semiconductor element, and a cooling structure using the same.

In recent years, a cooling technique for preventing overheating of a heat-generating component such as a semiconductor element mounted on various devices such as a personal computer or a device such as a power facility has attracted attention in recent years. Examples of a method for cooling an electric / electronic component requiring cooling (hereinafter referred to as a component to be cooled) include a method in which a fan is attached to the device to lower the temperature of the air in the device housing, and a method in which the component to be cooled has excellent heat conductivity. There is known a method in which a hot plate is attached and heat of a component to be cooled is released via the soaking plate.

As a soaking plate to be attached to a component to be cooled, for example, a ceramic material such as a copper material, an aluminum material, or a carbon material or an aluminum nitride is applied. I have. The plate heat pipe is a heat pipe having a plate shape, and may be called a flat heat pipe or a flat heat pipe.

Here is a brief description of the heat pipe. The heat pipe has a cavity sealed inside, and a working fluid (also referred to as a working fluid) is contained in the cavity. The inside of the cavity is evacuated, and the working fluid is apt to evaporate. As the working fluid, water, alcohol, CFC alternative, or the like is used.

作 動 The operation of the heat pipe will be described by taking an example of a general pipe shape. Assuming that one end side of the pipe-shaped heat pipe is a heat-absorbing section, the heat-absorbing section uses heat transmitted from the outside through the material of the container (container) constituting the heat pipe, thereby causing the internal working fluid to flow therethrough. Evaporates, and the vapor moves to a heat radiating portion on the other end side of the heat pipe. In the heat radiating section, the vapor of the working fluid is cooled and returns to the liquid state again. Then, the working fluid that has returned to the liquid phase moves (recirculates) to the heat absorbing side again. Heat is transferred by such phase transformation and movement of the working fluid.

還 流 The working fluid is recirculated by gravity or capillary action. In the case of a gravity type heat pipe, the heat absorbing portion may be arranged below the heat radiating portion. When the working fluid is refluxed by the capillary action, a groove is provided on the inner wall of the cavity, or a wick such as a metal mesh is inserted into the cavity.

(4) Connect the component to be cooled to the above-mentioned heat absorbing part. Then, for example, radiating fins may be attached to the radiating portion. With such a configuration, much of the heat of the component to be cooled is dissipated from the fins via the heat pipe.

By the way, in the case of a plate-type heat pipe, there is an advantage that it can be easily connected to a component to be cooled due to its shape. That is, it is possible to bring a part to be cooled, such as a semiconductor element, into contact with the principal surface thereof over a certain area. Incidentally, the contact may sandwich an intervening substance such as heat transfer grease or heat transfer rubber. Alternatively, in some cases, the bonding may be performed by soldering or the like. Further, a fin, a heat sink, a fan, or the like for radiating heat may be attached to the surface of the plate-shaped heat pipe opposite to the surface where the component to be cooled contacts. In this way, a cooling structure excellent in space efficiency can be realized.

The manufacturing cost of a plate-shaped heat pipe is likely to be higher than that of a normal round pipe-shaped heat pipe. Generally, a round pipe-shaped heat pipe is formed by welding and sealing both ends of a pipe manufactured by extrusion or the like to form a container.

For a plate-type heat pipe container, for example, a method is known in which two plate members are combined and assembled so as to form a cavity between the two plate members. In this case, one or both of the two plate members are curved in the hollow portion, and the curved portion is assembled so as to form a hollow portion, or a member of the plate thick portion of the plate type container after assembly is joined. Sometimes assembled.
JP-A-9-200975 JP-A-6-101980 JP-A-8-121982 JP-A-60-106633 Japanese Patent Publication No. 2-502479 JP-A-52-90852 JP-A-10-38484 JP-A-9-210572 Japanese Patent Application Laid-Open No. 9-3571 Microfilm disclosed in Japanese Patent Application No. 63-47888 (Japanese Utility Model Application Laid-Open No. 1-157491). JP-A-9-303979

However, in the method of assembling a container by combining two plate members, it is necessary to form a closed cavity in the container, so it is essential to securely join the outer peripheral portions of the plate members. For this work, a normal metal joining method such as welding or brazing may be applied, but the joining work for achieving a reliable sealing state over the entire circumference is not easy, and therefore, the plate-shaped heat This was one of the major causes of the increase in pipe manufacturing costs.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a plate-type heat pipe capable of reducing the number of parts and the cost of assembly. We also propose a cooling structure using the plate-type heat pipe.

The plate-type heat pipe of the present invention is a practical one that reduces the number of components and is excellent in productivity and the like. A cooling structure using the same enables efficient cooling of a component to be cooled.

The plate-type heat pipe according to the first aspect of the present invention is a plate-type heat pipe provided with a box-shaped container having a plate shape and one surface or only two opposing surfaces of a thickness portion thereof being joined and assembled. A convex portion for directly or indirectly contacting a component to be cooled is formed, and a heat conductive inner block is arranged in a portion corresponding to the convex portion in a cavity formed by the container. It is. A working fluid is contained in a closed cavity in the container. The convex portion may be formed in the container by hydraulic bulging.

The plate-type heat pipe according to the third aspect of the present invention is a plate-type heat pipe provided with a box-type container having a plate-type shape and one surface or only two opposing surfaces of a thickness portion thereof being joined and assembled. Is provided with a heat-conductive external block for directly or indirectly contacting a component to be cooled, and a heat-conductive internal block is provided at a portion of the cavity formed by the container where the external block is mounted. This is where the blocks are located.
When arranging the inner block and the outer block, they may be constituted by one integrated member.

The plate-type heat pipe according to the fifth aspect of the present invention is the plate-type heat pipe, wherein the box-shaped container is a plate-shaped member formed by deep drawing or backward extrusion, and only one surface of a thickness portion thereof has an opening. , And a box-shaped container formed by joining and assembling a lid member, and a plate-shaped container having only one surface of a thickness portion joined and assembled.

In the plate-type heat pipe according to the sixth aspect of the present invention, the box-shaped container is formed by joining and sealing both ends of a cylindrical body. The plate-shaped heat pipe according to any one of claims 1 to 4, further comprising a box-shaped container that is joined and assembled.

According to the plate-type heat pipe of the seventh aspect of the present invention, in the sixth aspect of the present invention, the box-shaped container has both ends of the tubular body crushed and closed.

The plate type heat pipe according to claim 8 is the plate type heat pipe according to any one of claims 1 to 7, wherein a wick member is provided in a hollow portion of the box type container.

According to a ninth aspect of the present invention, a component to be cooled is thermally connected to one main surface of the plate-type heat pipe according to any one of the first to eighth aspects, and a fin or the like is provided on the other surface. Is a cooling structure to which the heat sink member is attached.

According to a tenth aspect of the present invention, a cooled component to be cooled is thermally connected to one main surface side of the plate-type heat pipe according to any one of the first to eighth aspects, and a fin or the like is provided on the other surface side. Is a cooling structure to which the heat sink member and the fan are attached.

FIG. 1 is an explanatory view showing members (box-shaped members (box-shaped containers)) constituting the plate-type heat pipe of the present invention. The (a) box-shaped member 10 is a seamless member formed by forming a metal sheet by deep drawing or the like. The box-shaped member 10 has an opening 100 only on one surface of the plate thickness portion.

(1) As shown in FIG. 1 (A), the lid member 20 is joined to the opening 100 to form a box-shaped container having a cavity therein. The inside of the cavity is appropriately subjected to vacuum degassing or the like, and further contains an appropriate amount of a working fluid (water, alternative Freon, alcohol, or the like), and the cavity is hermetically sealed to manufacture the plate-type heat pipe 40.

(1) The injection / deaeration nozzle 30 shown in FIG. 1 (a) is provided for facilitating the above-described vacuum deaeration in the cavity and the work of enclosing the working fluid, and is not an essential member. In the case of this example, a pipe-shaped liquid injection and deaeration nozzle 30 is joined to the lid member 20. Alternatively, the cover member 20 may be partially formed and formed.

The injection and deaeration nozzle 30 is for injecting the working fluid into the hollow portion and then sealing it by welding or the like. By using such a small and nozzle-shaped injection and deaeration nozzle 30, the working fluid is removed. Has the advantage that the sealing operation is very easy while preventing the outside air from being mixed as much as possible. Although the shape of the liquid injection deaeration nozzle 30 is a pipe-shaped member for the sake of simplicity in the illustrated example, the shape is arbitrary. The operation may be determined in consideration of a working fluid injection operation, a deaeration operation, and a subsequent sealing operation.

FIG. 2 shows a plate-shaped heat pipe 41 in a case where the opening of a box-shaped member 11 similar to the box-shaped member 10 in FIG. 1A is crushed and further welded to form a hermetically sealed cavity. FIG. Reference numeral 110 in the figure is a crushed portion, and reference numeral 111 is a welded portion. In the case of this example, there is an advantage that the number of parts can be reduced because the lid member 20 as shown in FIG. Reducing the number of parts contributes to a reduction in manufacturing costs. In this case, a liquid injection deaeration nozzle is not provided. The opening of the box-shaped container 11 is directly sealed.

FIG. 3 shows an example in which a cavity is formed by sealing the opening of the box-shaped member 12 as in the case of the plate-type heat pipe 41 in FIG. 2 (the reference numeral 120 in the figure denotes a welded portion). In the case of (1), a liquid injection deaeration nozzle 31 is provided in the box-shaped member 12. The mounting position of the liquid injection deaeration nozzle 31 is not particularly limited. Normally, the main surface side of the plate-shaped heat pipe 42 is brought into contact with a component to be cooled such as a semiconductor element to be cooled, or a radiating fin or a heat sink block is attached. It is desirable to provide a liquid injection and deaeration nozzle 31 on the surface of the portion.

The box-shaped members 10 to 12 described above are box-shaped members having a substantially rectangular parallelepiped shape, and may be formed by subjecting a metal sheet to deep drawing or ironing.

The box-shaped members 10 to 12 each have a rectangular parallelepiped shape, but may be a box-shaped member having a rectangular cross section such as a trapezoid or a parallelogram in some cases.

The method of closing the openings of the box-shaped members 10 to 12 is not only a method of joining the lid member 20 as shown in FIG. 1 but also a method of crushing and joining the box-shaped member 11 itself as shown in FIG. There are methods. In any case, the joining method is not particularly limited, but a welding method, a brazing method, or the like may be applied.

The welding method includes, for example, methods such as TIG welding, plasma welding, laser welding, and electron beam welding. In the case of the brazing method, vacuum brazing, brazing in an atmosphere furnace, torch brazing and the like can be mentioned. Further, a welding method and a brazing method may be combined. For example, if laser beam welding is used in combination, it is possible to expect effects such as more reliable joining of fine portions. In any case, a joining method for closing the openings of the box-shaped members 10 to 12 may be appropriately selected in consideration of the material, shape, size, and the like of the members.

、 As the plate-type heat pipe of the present invention, a wick or a heat-conductive internal block may be arranged in the cavity. FIG. 4 is an explanatory view showing a case where the wick member 50 and the inner block 51 are accommodated in a box-shaped member 13 similar to the box-shaped member 10 of FIG. The wick member 50 may be made of, for example, a mesh of metal or the like, a mesh formed from the mesh (mesh molded body), a nonwoven fabric, a porous body, a block in which minute grooves are formed, or the like. As the inner block 51, a block made of a material having excellent heat conductivity such as a copper material may be used. In the example of FIG. 4, both the wick member 50 and the inner block 51 are accommodated in the box-shaped member 10, but one of them may be accommodated. It is natural that these are inserted into the box-shaped member 13 before the box-shaped member 13 is evacuated and sealed.

The mesh member 50 has a function of promoting the return of the working fluid by the capillary action in the plate-type heat pipe assembled by sealing the box-shaped member 13. For this reason, even if the plate-type heat pipe is in a reverse operation state (a state in which the heat absorbing portion is located above the heat radiating portion), a certain amount of reflux of the working fluid can be maintained.

The internal block 51 is desirably arranged at a place where the component to be cooled comes into contact with the plate-type heat pipe. By doing so, there are effects such as an increase in the area of a portion for transferring the heat of the component to be cooled to the working fluid. When the inner block 51 contacts the upper and lower inner walls of the box-shaped member 51, the inner block 51 also serves as a heat path between the inner walls. Further, in some cases, the mesh member 50 can be fixed by the inner block 51.

FIGS. 5 and 6 show examples in which convex portions 140 and 150 are provided on the box-shaped members 14 and 15. The convex portions 140 and 150 serve as contact portions with the parts to be cooled in the plate-type heat pipe assembled by sealing the box-shaped members 14 and 15.
The protrusions 140 and 150 may be formed by molding the box-shaped members 14 and 15.

The protruding portions 140 and 150 are plate-shaped, and a box-shaped member (a member like the box-shaped member 10 in FIG. 1) in which only one of the thickness portions or two opposing surfaces thereof have openings is prepared. The mold member may be formed by molding. In the case of FIG. 5, the projection 140 is located at the end of the box-shaped member 14.
For this reason, the convex portion 140 can be formed relatively easily by molding using a normal mold. Alternatively, when a metal sheet or the like is subjected to drawing processing to produce a box-shaped member in which only one of the thickness portions or two opposing surfaces thereof have openings in a plate shape, the convex portions 140 are formed from the beginning. It is also possible to process it into a given shape.

On the other hand, in the case of FIG. 6, since the convex portion 150 is located at the central portion of the box-shaped member 15, it is difficult to form the convex portion 150 by molding using a mold. Therefore, it is preferable to form by hydraulic bulging.

FIG. 7 is an explanatory view illustrating a case where the heat conductive internal block 141 is accommodated inside the convex portion 140 of the box-shaped member 14 provided with the convex portion 140 shown in FIG.
This internal block 141 has an effect of increasing the area of a portion for transmitting the heat of the component to be cooled to the working fluid, similarly to the internal block 51 in FIG.

FIG. 8 is an explanatory view showing a situation in which a heat-conductive outer block 160 is attached to a box-shaped member 16 similar to the box-shaped member 10 in FIG.
The outer block 160 may be a contact portion of the plate-type heat pipe assembled by sealing the box-shaped member 16 with the component to be cooled.

FIG. 9 is an explanatory diagram showing a form in which the inner block and the outer block are integrated. In this case, the terms “internal block” and “external block” are not meaningful per se, but the form is such that the internal block and the external block are integrated.
In FIG. 9, holes 170 and 171 are provided in the box-shaped member 17 so as to penetrate both main surfaces thereof, and an integrated block 172 is inserted and arranged so as to penetrate the holes 170 and 171. Of course, it is needless to say that the airtightness is maintained by joining the boundaries between the holes 170 and 171 and the integrated block 172. In the assembled plate-type heat pipe, the integrated block 172 has effects such as a reduction in the temperature difference between the two main surfaces of the integrated block 172 and the box-shaped member 17 and an increase in uniformity. The exposed surface of the integrated block 172 serves as a contact portion with the component to be cooled, and has an effect that the dimensional accuracy such as the flatness of the contact portion is easily increased.

Although the plate-type heat pipe of the present invention has been described above, a cooling structure using the same will also be described. As shown in FIG. 10, using a plate-type heat pipe 60 of the present invention, a component to be cooled 70 to be cooled is thermally connected to one main surface side (lower surface in this figure) of the heat pipe 60, The fins 61 may be attached to the other surface (the upper surface in this figure). The thermal connection between the plate-shaped heat pipe 60 and the component to be cooled 70 is not limited to a simple contact, but may be a contact with heat transfer grease or the like, a bonding such as soldering, or other thermal connection. Means The fins 61 promote heat dissipation of the plate-shaped heat pipe 60, and a fan may be further provided if necessary. Reference numerals 71 and 72 in the figure indicate leads and substrates. Such a cooling structure of the present invention is compact and efficient.

It is explanatory drawing which shows the member which comprises the plate type heat pipe concerning this invention. It is explanatory drawing which shows the member which comprises the plate type heat pipe concerning this invention. It is explanatory drawing which shows the member which comprises the plate type heat pipe concerning this invention. It is explanatory drawing which shows the member which comprises the plate type heat pipe concerning this invention. It is explanatory drawing which shows the member which comprises the plate type heat pipe concerning this invention. It is explanatory drawing which shows the member which comprises the plate type heat pipe concerning this invention. It is explanatory drawing which shows the member which comprises the plate type heat pipe concerning this invention. It is explanatory drawing which shows the member which comprises the plate type heat pipe concerning this invention. It is explanatory drawing which shows the member which comprises the plate type heat pipe concerning this invention. It is explanatory drawing which shows the example of the cooling structure using the plate type heat pipe of this invention.

Explanation of reference numerals

DESCRIPTION OF SYMBOLS 10 Box-shaped member 100 Opening part 20 Cover member 30 Injection deaeration nozzle 40 Plate-shaped heat pipe 11 Box-shaped member 110 Crushed part 111 Welded part 41 Plate-shaped heat pipe 12 Box-shaped member 120 Welded part 31 Injection deaeration nozzle 42 Plate heat pipe 13 Box-shaped member 50 Wick member 51 Inner block 14 Box-shaped member 140 Convex part 15 Box-shaped member 150 Convex part 141 Inner block 16 Box-shaped member 160 External block 17 Box-shaped member 170 Hole 171 Hole 172 Integrated Block 60 Plate heat pipe 61 Fin 70 Component to be cooled 71 Lead 72 Board

Claims (10)

In a plate-type heat pipe provided with a box-shaped container in which only one surface or two opposing surfaces of a thickness portion thereof are joined and assembled, a component to be cooled is directly or indirectly contacted with the container. A plate-shaped heat pipe, wherein a convex portion to be formed is formed, and a heat-conductive inner block is arranged in a portion corresponding to the convex portion in a hollow portion formed by the container. The plate-shaped heat pipe according to claim 1, wherein the convex portion is formed by hydraulic bulging on the container. In a plate-type heat pipe provided with a box-shaped container in which one surface or only two opposing surfaces of a thickness portion are joined and assembled, a component to be cooled is directly or indirectly attached to an outer surface of the container. A plate-type heat pipe, wherein a heat-conductive outer block is attached to the container, and a heat-conductive inner block is arranged in a portion of the cavity formed by the container where the outer block is mounted. The plate-type heat pipe according to claim 3, wherein the outer block and the inner block are formed as one integrated member. The box-shaped container is a plate formed by deep drawing or backward extrusion, and a plate-shaped member having only one surface of its thickness portion as an opening, and a lid member joined and assembled. The plate type heat pipe according to any one of claims 1 to 4, wherein the plate type heat pipe is a box-shaped container in which only one surface of a thickness portion of the die is joined and assembled. The said box-shaped container is a box-shaped container formed by joining and sealing both ends of a cylindrical body, and formed by joining and assembling only two opposing surfaces of a thickness portion in a plate shape. Item 5. A plate-shaped heat pipe according to any one of Items 1 to 4. The flat heat pipe according to claim 6, wherein the container has both ends of the tubular body crushed and closed. The plate-shaped heat pipe according to any one of claims 1 to 7, wherein a wick member is provided in the hollow portion of the container. The component to be cooled, which is a cooling object, is thermally connected to one main surface side of the plate-shaped heat pipe, and fins or other heat sink members are attached to the other surface side. A cooling structure using the plate-type heat pipe described in Crab. 9. A cooled component to be cooled is thermally connected to one main surface of the plate-shaped heat pipe, and fins and other heat sink members and a fan are mounted to the other surface. A cooling structure using the plate-type heat pipe described in any one of the above.

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