JP2003282804A - Heat sink device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To contrive an optimal relation between the shape of a heat sink device and a fan so as to realize the heat sink device of higher cooling efficiency. <P>SOLUTION: The heat sink device 10 is equipped with a heat sink 9 provided with a plurality of fins 8 which are nearly square, platelike and arranged in the direction of thickness, and the fan 4 which is provided with a rotating shaft extending in a vertical direction and mounted at the center of the upper end of the heat sink 9. Slits 6 are provided to the fins 8 as penetrating through the fins 8 in the direction of thickness, and the slits 6 dispersedly located on the uppermost fin 8 descend downward so as to converge at the center line of the lower fin 8. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a heat dissipation device. In particular, this heat dissipation device is a CPU (Central Processing Unit: Centr
It can be suitably used for cooling an al Processing Unit).

[0002]

2. Description of the Related Art Certain electronic components such as a CPU generate heat during use, and if an abnormally high temperature is generated, the processing will be hindered. A conventional heat dissipation device for a CPU generally comprises a combination of a heat sink having a plurality of plate-shaped fins and a fan provided on the heat sink. Then, the heat generated from the CPU conducts in the heat sink and is radiated from the surface of the fin. Next, the air heated on the fin surface is forced to be convected by the air blown from the fan and replaces the cooled air.

As a heat dissipation device of this kind, in order to smooth the flow of air flowing from a fan and prevent the backflow of air,
A configuration has been proposed in which the upper ends of the fins are curved downward (Registered Utility Model No. 3063556). FIG. 2 is an exploded perspective view showing details of the heat dissipation device, in which the bottom plate 101 is provided on the CPU 105 mounted on the motherboard m.
A fin group 102 composed of a large number of plate-shaped fins 106 is attached on top of it. The fin group 102 covers 10.
3, the bottom plate 101, the fin group 102 and the cover 103 constitute a heat sink, and a fan 104 for forced cooling is fixed on the cover 103. By the way, the intervals of the fins 106 are regulated by the bent claws 107 of the fins 106 to be evenly spaced. A curved space is provided between the fin 104 and the fan 104 by the curved portion 108 at the upper end of the fin 106. In the above registered utility model publication, this curved space is defined by the fan 10
It is described that the flow of air flowing in from 4 is made smooth and the backflow of air is prevented.

[0004]

However, the structure of the heat dissipation device described in the above registered utility model is biased toward the purpose of smoothing the flow of air flowing from the fan and preventing backflow of air, and the cooling efficiency is not so high. Not improved. Therefore, an object of the present invention is to provide a heat dissipation device having a higher cooling efficiency.

[0005]

In order to solve the problem, a heat dissipation device of the present invention is a heat sink having a plurality of fins which are substantially rectangular plate-shaped and arranged in the thickness direction.
At the center of the upper end of the heat sink, in a heat dissipating device including a fan attached with the rotating shaft in the vertical direction, the fin has a slit penetrating in the thickness direction,
It is characterized in that the slit descends from the non-center position of the upper end portion toward the lower end portion and approaches the center along with the lowering.

When a heat dissipation device combining a heat sink and a fan is mounted on a heat dissipation object such as a CPU,
The part where the heat sink absorbs the most heat from the object to be radiated and tends to reach a high temperature is the center part of the heat sink. On the other hand, since the wind from the fan is sent by the blades of the fan, the air volume is small immediately below the rotating shaft and large under the blades.

Therefore, according to the present invention, the slits descend from the non-center position of the upper end portion toward the lower end portion, and the slit approaches the center along with the lowering, thereby taking in the wind from under the blades.
The captured wind was guided by the slit and directed toward the center. By leaving the fins surrounded by the slits in the central portion, the heat radiation area and the heat capacity of the heat sink in the central portion are secured as much as possible with a limited occupied volume. Therefore, the heat from the heat dissipation target can be quickly absorbed and continuously released. This is different from the registered utility model in that the center portion is not a fin body but a curved space.

It is preferable that the slit has a slope that becomes gentle as it goes down. Since the wind from the fan first goes downward, it is possible to blow the air with less pressure loss by having a steep gradient at the beginning and a gentle gradient as it descends. Further, it is preferable that the fin has a second slit that vertically descends from the center position of the upper end portion. The wind collected in the center is quickly discharged through the second slit,
This is because the following wind flows in with less resistance.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment 1 An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view showing a heat dissipation device of a CPU according to an embodiment. The heat dissipation device 10 includes a heat sink 9 and a fan 4. For details, see C mounted on the motherboard m.
A connecting plate 1 is arranged on the PU 7, and a fin group 8 in which a large number of fins 2 are arranged at equal intervals in the thickness direction is located on the PU 7, and the entire upper surface of the fin group 8 is covered with a cover 3. The fins 2 are heat-welded to the connecting plate 1, and the connecting plate 1, the fin group 8 and the cover 3 constitute a heat sink 9.
The fan 4 is mounted on the cover 3 with the rotating shaft 41 in the vertical direction. A circular hole is formed in the cover 3 such that the blades 42 of the fan 4 are inscribed in plan view, and the wind generated by the fan 4 passes through the circular hole and enters the heat sink 9.

Each of the fins 2 basically has a rectangular plate-like symmetrical shape, but has a slit 5 penetrating in the thickness direction from the upper end to a certain depth in the vertical direction at the center, and slits on both sides thereof as they descend. There is a slit 6 which is close to 5 but which is not connected to the slit 5 and which has an arc shape of about 1/4. Therefore,
The slit 5 and the slit 6 on one side form the substance of the fin 2 having a quarter circular shape. The width of the slit 6 is wide at the entrance of the upper end and becomes narrower as it goes down.

The heat generated from the CPU 7 is transmitted to the fin group 8 via the connecting plate 1. Then slit 5 and slit 6
Each fin 2 including the above-mentioned 1/4 circular portion surrounded by
Transmitted to the air near the surface of the. On the other hand, the velocity of the wind sent from the fan 4 is weakest immediately below the rotating shaft 41, and the blade 42
Becomes stronger as you go to the outer circumference. According to this heat dissipation device, a strong wind immediately below the blade 42 is taken in from the upper end of the slit 6, and the wind is guided by the slit 6 toward the center of the fin 2. The hot air heated in the center of the fin 2
Slit 5 pushed by the cold air sent from slit 6
Is released through. Therefore, forced convection can be efficiently performed with a small pressure loss. At the same time, the replaced cool air absorbs heat from the fins 2 having a large surface area including the ¼ circular portion. Therefore, the cooling effect is excellent.

-Embodiment 2- A heat sink used in a heat dissipation device of a second embodiment of the present invention is shown in a perspective view in FIG. Also in the heat dissipation device of the second embodiment, the fan 4 shown in FIG.
It is common with the first embodiment in that U7 is located. Therefore,
Hereinafter, the heat sink 19 will be mainly described.

The heat sink 19 is composed of a large number of plate-shaped fins 12 and is arranged at equal intervals in the thickness direction of the fin group 1.
8 and a connector 11 for connecting the fin 12. As shown in the perspective view of FIG. 4, the connector 11 includes a lower plate 11a and side plates 11b and 11c that are integrally erected on both sides of the lower plate 11a. A plurality of grooves are formed on the upper surface of the lower plate 11a in parallel with the side plates 11b and 11c. 11d is formed.

As shown in the perspective view of FIG. 5, the fin group 18 basically has a symmetrical shape of a rectangular plate, and penetrates in both sides in the thickness direction and approaches the center as it descends. Although it is common with the first embodiment in that it has an arcuate slit 16, a vertical slit is not formed in the center. Therefore, the two slits 16 and 16 form the substance of the fin 12 having a ½ circle or bowl shape. The width of the slit 16 is wide at the entrance of the upper end and narrows as it goes down. And, the lower end of the fin 12 is the groove 11
By being inserted into d, the fins 12 are fixed to the connector 11 and the intervals between the fins 12 are determined.

According to this embodiment, the distance between the fins 12 can be freely changed. Therefore, for example, in the central portion where the wind speed of the fan is low, the fins 12 can be intermittently inserted into the grooves 11d to widen the gap between the fins 12 to reduce the pressure loss and secure the air volume. On the contrary, in the vicinity of the side plates 11b and 11c where the wind speed is strong, the fins 12 can be continuously inserted into the grooves 11d to increase the number of fins 12 per unit area and secure a large heat radiation area and heat capacity. In this embodiment, as in the first embodiment, a vertical slit may be formed in the center of the fin 12.

Although the embodiment of the heat dissipation device according to the present invention has been described above, the present invention is not limited to such an embodiment, and various variations and modifications can be made without departing from the scope of the invention. . For example, the shape of the slit descending from the non-center position of the fins and approaching the center as the fin descends is described as a shape having a gentle slope in the above-mentioned embodiment, but the slit is centered at a constant slope from the non-center position. A straight line shape that faces toward is also applicable to the present invention.
Further, by slightly curving the upper ends of the fins, more air from the fan may be collected in the center. Furthermore, regarding the method of forming the heat sink, in the present embodiment, the description is based on crimp fin forming in which a plurality of plate-shaped fins are connected to the connecting plate or the connecting tool, but it is also applicable to extrusion forming, and in that case. The slits 5, 6, 16 may be formed by wire cutting on each fin of the extruded heat sink.

[0017]

According to the heat dissipating device of the present invention, it is possible to efficiently use the wind of the fan without reducing the heat capacity and the heat dissipating area of the heat sink, so that the cooling effect is excellent.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a heat dissipation device according to a first embodiment.

FIG. 2 is an exploded perspective view showing a conventional heat dissipation device.

FIG. 3 is a perspective view showing a heat sink applied to the heat dissipation device of the second embodiment.

FIG. 4 is a perspective view showing a connector of the heat sink.

FIG. 5 is a perspective view showing a fin group of the heat sink.

[Explanation of symbols]

1, 11 Connecting plate or connecting tool 2,12 fins 3 cover 4 fans 5, 6, 16 slits 7 CPU 8, 18 fin group 9, 19 Heat sink 10 Heat dissipation device 101 bottom plate 102 fins 103 cover 104 fans 105 CPU 106 fins 107th 108 Bend

Claims (3)

[Claims] 1. A heat dissipating device comprising a heat sink having a plurality of fins each having a substantially rectangular plate shape and arranged in the thickness direction, and a fan mounted at the center of an upper end portion of the heat sink with a rotating shaft in the vertical direction. In the above, the fin has a slit penetrating in the thickness direction, the slit descends from the non-center position of the upper end portion toward the lower end portion, and as it descends, approaches the center. apparatus. 2. The heat dissipation device according to claim 1, wherein the slit has a slope that becomes gentle as it goes down. 3. The heat dissipation device according to claim 1, wherein the fin has a second slit that vertically descends from the center position of the upper end portion.