JP3413152B2 - heatsink - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultra-thin heat sink for cooling various electronic components such as semiconductor elements, and more particularly to a heat sink including a flat heat pipe and a plurality of U-shaped plate fins. .

[0002]

2. Description of the Related Art Electronic components such as semiconductor elements mounted on various devices such as personal computers and electric / electronic devices such as electronic equipment are unavoidable to generate a certain amount of heat due to their use, and in recent years it is important to cool them. It is becoming a technical issue. As a method of cooling an electric / electronic element that requires cooling, for example, a fan is attached to the equipment to lower the temperature of the air in the equipment housing, or a cooled body is attached to the cooled element to cool the cooled element. Methods and the like are typically known.

As the cooling body to be mounted on the element to be cooled, not a simple heat-conducting metal material but a cooling body having a heat pipe structure or a round heat pipe having excellent heat conductivity such as a copper material or an aluminum material is mounted. The one in the form has been proposed and put into practical use. The heat pipe has a sealed cavity, and heat is transported by the phase transformation and movement of the working fluid contained in the cavity. Some of the heat is
Most of the heat is carried by the phase transformation and transfer by the working fluid, although it is carried directly through the container that constitutes the heat pipe.

On the heat absorbing side of the heat pipe, the working fluid evaporates due to the heat transmitted through the material of the container forming the heat pipe, and the vapor moves to the heat radiating side of the heat pipe. . On the heat radiation side, the vapor of the working fluid is cooled and returns to the liquid phase state again. Then, the working fluid that has returned to the liquid phase moves (refluxes) to the heat absorption side again. Heat is transferred by such phase transformation and transfer of the working fluid.

The working fluid in the heat pipe is usually
Water, aqueous solution, alcohol, or other organic solvent is used. Mercury may be used as a working fluid as a special application. As described above, the heat pipe utilizes the action such as phase transformation of the working fluid inside, so it is manufactured so as to avoid mixing of gases other than the working fluid into the sealed interior as much as possible. . Such a contaminant is, for example, carbon dioxide gas dissolved in the atmosphere (air) or the working fluid that is usually mixed during the manufacturing.

As the shape of the heat pipe, a flat type is widely used in addition to a typical round pipe shape. Due to its shape, the flat heat pipe has an advantage that it can be easily brought into contact with a cooled element such as a semiconductor element in a wide area. Further, a heat sink has been widely used in which heat transferred by a heat pipe is forcibly cooled by using a fan or the like.

Furthermore, in recent years, electronic equipment has been
It incorporates high output and highly integrated components such as U. Since various electronic components such as semiconductor elements have a very high degree of integration and perform processing such as information calculation and control at high speed, a large amount of heat is generated. There is a demand for a device for cooling the heat of a semiconductor device or the like, which is a high output and highly integrated component.

[0008] Further, the number of opportunities for activities via the Internet has rapidly increased, and the number of situations in which a desktop fixed computer cannot fully exhibit its functions has been increasing. In other words, it is important to consider that personal computers equipped with various electronic components such as CPUs should be miniaturized and have mobility so that the functions of the personal computers can be fully exerted both during the journey by car and while traveling. Is becoming popular.

Along with this, heat sinks for cooling various electronic components such as CPUs are also required to be small and thin. FIG. 6 shows a conventional heat sink using a heat pipe. FIG. 7 is a partially enlarged view of a conventional heat sink. As shown in FIG. 6, the conventional heat sink includes a round heat pipe 20 and a plurality of heat radiation fins 21 provided at one end (that is, the heat radiation side) of the round heat pipe 20. In the conventional heat sink, as shown in FIG. 7, in order to enhance the heat radiation effect, a hole is made in the central portion of the radiation fin 21 by burring 22 and the round heat pipe 20 is inserted into the opening,
The radiation fin and the round heat pipe are connected.

However, in the conventional heat sink shown in FIG. 6, the heat radiation fin 21 into which the round heat pipe 20 is inserted has a height higher than a predetermined value, for example, 1
There is a fatal defect that the value exceeds 0 mm and it cannot be mounted on the above-mentioned ultra-thin personal computer having high mobility.

[0011]

[Problems to be Solved by the Invention] As described above, CP
A personal computer on which various electronic components such as U are mounted is thin and small, and the space for arranging a heat sink for cooling a highly integrated CPU is restricted, and a heat sink with high performance is required. In particular, when a height of 10 mm or less, and further, a height of 7 to 8 mm is required, there is a problem that the above-described conventional heat sink cannot handle it.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a heat sink excellent in heat dissipation which can be mounted on a thin and small electronic device having high mobility.

[0013]

The present inventor has conducted extensive studies to solve the above-mentioned conventional problems. as a result,
A flat heat pipe having a thickness of, for example, 1.5 mm or less is used, which is made of a U-shaped plate material including an upper surface portion, a vertical surface portion, and a lower surface portion, and is formed at the bottom of the vertical surface portion.
A plate part having a plurality of plate-shaped fins having a square-shaped opening into which the flat heat pipe is inserted is attached to the end of the flat-shaped heat pipe described above, and a plate having a square-shaped opening. Thin fins with high mobility by blowing air from a plurality of rectangular openings arranged in parallel on both side surfaces of the fins in which a plurality of fins are arranged in parallel to each other and forcibly air cooling It was found that it is possible to provide a heat sink that can be mounted on a personal computer or the like and that has excellent heat dissipation performance.

The present invention has been made on the basis of the above findings, and the first aspect of the heat sink of the present invention is a heat sink comprising the following members: (a) Working fluid is sealed and hermetically sealed. A flat heat pipe having a hollow portion; and (b) a flat U-shaped plate member having an upper surface portion, a vertical surface portion and a lower surface portion, which is formed at the bottom of the vertical surface portion and accommodates the flat heat pipe. A fin portion in which a plurality of plate-shaped fins having a V-shaped opening are arranged in parallel.

A second aspect of the heat sink of the present invention is
The opening is a heat sink characterized in that it has a rectangular shape having four circumferences formed by the vertical portion and the lower surface portion.

A third aspect of the heat sink of the present invention is
The opening portion has an upper end portion having an edge portion extending in the same direction and parallel to the lower surface portion, having substantially the same width as the lower surface portion, and closely contacting the upper surface of the heat pipe. It is a heat sink.

A fourth aspect of the heat sink of the present invention is
The heat sink is characterized in that the edge of the opening is in close contact with the upper surface of the flat heat pipe, and the lower surface is in close contact with the lower surface of the flat heat pipe.

According to a fifth aspect of the heat sink of the present invention,
A heat sink, characterized in that a plurality of plate-shaped fins each having the square-shaped opening are arranged in parallel on both side surfaces of the fin, and both side surfaces of the fin are provided with a plurality of rectangular openings arranged in parallel. .

Another aspect of the heat sink of the present invention is the heat sink, wherein the flat heat pipe is provided with a curved portion.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a heat sink of the present invention will be described in detail with reference to the drawings. The heat sink of the present invention is composed of a flat heat pipe having a closed cavity in which a working fluid is sealed, and a U-shaped plate member composed of an upper surface portion, a vertical surface portion and a lower surface portion, and the lowermost portion of the vertical surface portion. A plurality of plate-shaped fins having a square-shaped opening for accommodating the flat heat pipe formed are arranged in parallel.

FIG. 1 is a perspective view of one aspect of the heat sink of the present invention viewed from the front side. As shown in Figure 1,
At one end (that is, the heat radiation side) of the flat heat pipe 2, there is provided a fin portion 3 in which a plurality of plate-like fins 4 each having a square-shaped opening are arranged in parallel. The flat heat pipe 2 of the present invention has, for example, a thickness of 1 mm and a width of 10 m.
It is a thin flat heat pipe of m. A mesh-shaped wick (not shown) is built in the sealed cavity of the flat heat pipe, and a working fluid (not shown) is enclosed therein. A mesh wick is placed in the center of the flat heat pipe to facilitate the return of the hydraulic fluid.
Both sides may be opened as passages. The thickness of the flat heat pipe of the present invention is preferably less than 1.5 mm.

FIG. 2 is a perspective view of one aspect of the heat sink of the present invention viewed from the back side. FIG. 3 is a perspective view from the front side of one embodiment of the plate fin of the present invention. FIG. 4 is a perspective view from the back side of one embodiment of the plate fin of the present invention. As shown in FIG. 3, the plate-shaped fin 4 is made of a U-shaped plate member including an upper surface portion 5, a vertical surface portion 6 and a lower surface portion 7, and is formed in the lowermost portion of the vertical surface portion 6 and has the flat shape. It has a square-shaped opening 8 for accommodating the heat pipe 2. The above-described opening 8 has a rectangular shape in which the vertical portion 6 forms three sides on the upper side and the both sides, and the lower surface portion 7 forms one side. That is, the flat heat pipe 2 is inserted into the opening 8. As shown in FIG. 4, the opening 8 into which the flat heat pipe is inserted
Is formed at the bottom of the vertical plane.

Further, in order to facilitate the thermal connection between the flat heat pipe 2 inserted in the square-shaped opening 8 and the U-shaped plate member 4, the lower surface is formed at the upper end of the opening 8. The edge portion 9 extends in the same direction as and parallel to the portion 7, has the same width as the lower surface portion 7, and has an edge portion 9 that is in close contact with the upper surface of the flat heat pipe 2. By forming the opening in this way,
The upper surface of the flat heat pipe 2 is thermally connected to the edge portion 9 of the opening, and the lower surface of the flat heat pipe 2 is thermally connected to the lower surface portion 7 of the U-shaped plate member 4, so that The heat from the heating element is radiated to the outside from the heat radiation side of the flat heat pipe 2 through the fin portion 3. That is, the area of the contact portion between the flat heat pipe 2 and the fin 4 is increased.

The flat heat pipe includes a flat heat pipe having a flat or planar shape at least in such a portion to be thermally connected to the plate fin. Therefore, a plate-shaped heat pipe may be used in addition to the heat pipe obtained by flattening the cylindrical heat pipe. Since both side surfaces of the fin portion in which a plurality of plate-like fins 4 having the square-shaped opening 8 are arranged in parallel are provided with a plurality of rectangular openings 10 arranged in parallel, either one of (( By sending air by a fan or the like (not shown) to perform forced air cooling, the heat radiation effect of the heat sink can be further enhanced. As shown in FIG. 2, the lower surface portion 7 of the plate fin 4 is in close contact with the flat heat pipe.

FIG. 5 shows a cross section of a heat sink in which a plurality of plate fins are attached to the end of a flat heat pipe. As shown in FIG. 5, the flat heat pipe is in close contact with and thermally connected to the lower surface portion 7 of the plate fin 4 and the edge portion 9. As shown in FIG. 5, a rectangular opening 10 having a wide space is formed.

Further, the flat heat pipe 2 may be provided with a curved portion in accordance with the arrangement position of the heating element such as CPU in the electronic equipment. That is, the heat absorbing portion of the flat heat pipe is connected to a heating element such as a CPU, and the flat heat pipe is provided with a curved portion that bends in a substantially right-angle direction, for example, in a central portion,
Furthermore, the fin portion 3 may be provided on the heat radiation side of the other end by linearly extending over a predetermined length.

As the material of the container of the heat pipe of the present invention, a metal having good heat conduction such as copper or aluminum can be used. As the wick, a member made of the same material as that of the flat heat pipe container can be used. As the working fluid, water, CFC substitute, or Fluorinert is used depending on the compatibility with the material of the heat pipe container. The material of the container is preferably copper, which has excellent compatibility with water as a working fluid.

[0028]

EXAMPLES The surface heat pipe of the present invention will be described in more detail below with reference to examples. The heat sink of the present invention shown in FIG. 1 was manufactured by the method described below.
That is, a U-shaped plate member (plate fin) 4 was prepared from an aluminum plate member having a plate thickness of 0.5 mm. The upper and lower surfaces of the plate fin are 1.5 mm wide and 20 m long, respectively.
The vertical surface portion connecting the upper surface portion and the lower surface portion has a height of 7 mm and a width of 20 mm.

Further, at the bottom of the vertical surface portion, a height of 1 mm,
A square-shaped opening 8 having a length of 8 mm is provided. An edge having a width of 1.5 mm and a length of 7 mm is provided at the upper end of the square-shaped opening. The 12 U-shaped plate materials thus prepared were arranged in parallel, and the rectangular opening 10 was formed on the side surface.
The fin portion 4 having the formed was prepared.

Next, a flat heat pipe container having a thickness of 1 mm and a width of 7 mm was prepared from an OFC (oxygen-free high conductivity copper) material. An OFC mesh wick was installed in the center of the container, and both sides of the container were opened as passages. Pure water was used as a working liquid, and the container was sealed in a container and hermetically sealed under reduced pressure. The flat heat pipe thus prepared was inserted into the square-shaped opening 8 of the fin portion to prepare a heat sink.

In the heat sink of the present invention thus prepared, the upper surface of the flat heat pipe and the plurality of edges provided at the upper end of the square-shaped opening are in close contact with each other, and The lower surface and the lower surface of the plurality of U-shaped plate members are in close contact with each other. Furthermore, by arranging a plurality of U-shaped plate materials in parallel, a fan having the same height as the fin portion was attached to one end of the plurality of rectangular openings 10 formed in the side surface portion.

The heat sink of the present invention is a very small heat sink having a height of 7 mm, and is forcedly cooled by a fan from a plurality of rectangular openings that are widely opened. It can be used to cool a CPU mounted on a small personal computer.

[0033]

As described above, according to the present invention, it is possible to provide a heat sink having excellent heat dissipation performance, which can be mounted on a thin and small electronic device having high mobility, and particularly, a heat sink having a height of 10 mm or less. It is possible and has high utility value in industry.

[Brief description of drawings]

FIG. 1 is a perspective view of one aspect of a heat sink of the present invention viewed from the front side.

FIG. 2 is a rear perspective view of one aspect of the heat sink of the present invention.

FIG. 3 is a front perspective view of one embodiment of the plate fin of the present invention.

FIG. 4 is a rear perspective view of one embodiment of the plate fin of the present invention.

FIG. 5 is a schematic cross-sectional view showing a cross section of a heat sink in which a plurality of plate-shaped fins are attached to an end portion of a flat heat pipe.

FIG. 6 is a diagram showing a conventional heat sink using a heat pipe.

FIG. 7 is a partially enlarged view of a conventional heat sink.

[Explanation of symbols]

1. heatsink 2. Flat heat pipe 3. Fin part 4. U-shaped plate material 5. Top part 6. Vertical surface 7. Lower surface 8. Square shaped opening 9. Edge 10. Rectangular opening 20. Round heat pipe 21. fin 22. Burring process

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masaru Oumi 2-6-1, Marunouchi, Chiyoda-ku, Tokyo Furukawa Electric Co., Ltd. (56) Reference JP-A-2-211657 (JP, A) JP-A 9-203590 (JP, A) Actual development Sho 62-182600 (JP, U) Actual development 3-64368 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01L 23/34 -23/473

Claims (5)

(57) [Claims] 1. A flat heat pipe having a heat sink (a) hermetically sealed cavity, comprising:
(B) A plate-shaped fin made of a U-shaped plate having an upper surface portion, a vertical surface portion, and a lower surface portion, and having a square-shaped opening portion for accommodating the flat heat pipe formed at the lowermost portion of the vertical surface portion. Fins arranged in parallel. 2. The heat sink according to claim 1, wherein the opening has a rectangular shape having four circumferences formed by the vertical portion and the lower surface portion. 3. The opening portion has, at an upper end portion thereof, an edge portion extending in the same direction and parallel to the lower surface portion, having an approximately same width as the lower surface portion, and closely contacting an upper surface of the heat pipe. The heat sink according to claim 1, wherein the heat sink is a heat sink. 4. The edge of the opening is in close contact with the upper surface of the flat heat pipe, and the lower surface is in close contact with the lower surface of the flat heat pipe. Heat sink described in. 5. The fin portions on which a plurality of plate-shaped fins having the U-shaped opening are arranged in parallel are provided with a plurality of rectangular openings arranged in parallel. The heat sink according to any one of claims 1 to 4.