JP2003086984A - Electronic component cooling system - Google Patents

Abstract

(57) [Problem] To provide a cooling device for an electronic component which has improved heat radiation performance of heat generated from a high heat-generating electronic component and which has been reduced in size and weight. A heat sink having a plurality of fins on an upper surface of a heat transfer plate portion which is in contact with a heating element to be cooled, wherein a thickness of a cross section perpendicular to a heat receiving surface of the heat transfer plate portion is at least one. A cooling device comprising: a heat sink having a shape that gradually increases toward the other side to enhance the effect of diffusing heat from a heating element; and a fan provided as a blowing unit on the heat sink. By arranging them only near the blades of the cooling fan at both ends of the plate, the air exhaustability is improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat sink used for cooling a semiconductor such as a micro processing unit (hereinafter abbreviated as MPU) used in a personal computer or the like which generates heat, or an electronic component having other heat generating portion. And a cooling device for an electronic component that cools a heating element by combining a heat sink with a blowing means such as a fan.

[0002]

2. Description of the Related Art In recent years, in electronic equipment, in order to ensure normal operation of electronic parts, the electronic parts such as semiconductors have been highly integrated and the operating clock has been increased in frequency to increase the heat generation amount. How to keep the contact temperature of parts within the operating temperature range has become a big problem. In particular, high integration and high frequency of a micro processing unit (hereinafter abbreviated as MPU) are remarkable, and heat dissipation measures have become an important issue in terms of stability of operation and ensuring of operation life.

Generally, in order to cool a heating element such as an MPU, a heat sink for expanding a heat radiation area and efficiently exchanging heat with a refrigerant such as air, and a force such as forcing a refrigerant such as air into the heat sink. Made with a fan with a motor.

Here, a conventional technique will be described with reference to FIGS. 5, 6 and 7.

FIG. 5 is a perspective view, a front view and a side view of a main part of a conventional cooling device. FIG. 6 is a perspective view of a main part of a conventional cooling device and a velocity distribution diagram of air exhausted from a heat sink to the outside. FIG. 7 is a perspective view of a main part of a conventional cooling device including a fan and a flat plate, and a velocity distribution diagram of air exhausted from a heat sink to the outside.

In general, a heat sink is mainly made of a material having a high thermal conductivity such as aluminum or copper, and is subjected to a method such as extrusion molding (also called pultrusion molding), cold forging, die casting and thin plate lamination. Is manufactured in.

In such a cooling device, when it is attached to a heating element, a heat sink is used in contact with the heating element 3 as shown in FIG. 5 (b). The cooling principle of the actual cooling device is that the heat generated by the heating element as shown in FIG.
Heat transfer plate 2b having high heat transfer property such as aluminum
The heat is transferred to the plate-shaped fins 1b through the heat transfer to the air sent from the cooling fan 4 on the surface of the plate-shaped fins 1b, so that the heat is dissipated into the air and cooled.

In order to improve the performance of the cooling device, it is most desirable that heat is evenly distributed over the entire heat transfer portion and that heat can be radiated from all the fins formed for heat radiation. However, in the conventional heat sink having plate-shaped fins as shown in FIG. 5, the heat from the heating element is very small compared to the heat transfer part and the contact area is narrow. Although heat is likely to be concentratedly transferred to the plate-shaped fins, heat tends to be relatively hard to be transferred to the radiation fins in the peripheral portion, and as a result, the entire radiation fin is often not functioning effectively. Also, if the air volume around the plate-shaped fins is the same, if the number of fins is increased and the surface area is increased, then the heat dissipation capacity will simply increase, but in fact, when considering per unit area, if the number of heat dissipation fins increases, As the range where air can flow in decreases, the gap between the plate-shaped fins becomes narrower, so the air inflow resistance increases, and the total amount of air flowing in itself decreases. On the contrary, the heat dissipation capability may be reduced. In other words, simply increasing the number of radiation fins has no effect.

The most important factor here is whether the heat from the heating element can be efficiently transmitted to the radiating fins in the widest possible area, as described above, and a sufficient radiating area can be secured while maintaining a sufficient radiating area between the fins. It is necessary that the electronic component cooling device has a structure capable of sending a sufficient amount of air required for heat radiation.

[0010]

However, in the case of electronic parts such as semiconductors, the heat generation tends to increase more and more due to the further increase in speed, and when the cooling device of the conventional structure is used, sufficient cooling is achieved. It has become difficult to perform the above, and especially with high heat-generating electronic components such as MPU, the performance cannot be fully exhibited,
Alternatively, thermal runaway or the like occurs, causing problems such as abnormalities in electronic devices. It is also possible to increase the cooling capacity by relatively increasing the cooling device itself as the amount of heat generated increases, but the size of the electronic device itself naturally limits the size and weight of the cooling device. There is also.

Generally, in consideration of ensuring the maximum air flow from the fan, the cooling device has a structure in which air is blown from the fan to a heat transfer plate having no fins, as shown in FIG. 7 (a). In this case, since the air blown from the fan has no fins that act as a fluid resistance that leads to a reduction in the air volume, the maximum air volume of the fan can be directly sent to the heat transfer plate. When the velocity distribution of the air at this time is represented in the club as a vector in the X and Y directions, the velocity distribution according to the rotation direction of the fan is obtained as shown in FIG. 7B. But,
In this case, a sufficient amount of air can be secured, but the heat transfer plate alone cannot secure a heat dissipation area that contributes to sufficient heat dissipation due to the small surface area, and as a result, sufficient heat dissipation performance cannot be obtained. There is.

On the other hand, in the conventional heat sink having plate-shaped fins as shown in FIG. 5, the plate-shaped fins themselves have a large cross-sectional area, and heat can be transferred from the heat transfer plate 2b to the fins relatively easily. In addition to being a structure that can easily obtain a uniform temperature distribution, it is also easy to secure a surface area necessary for heat dissipation, and it is a preferable structure in terms of the above-mentioned uniform temperature distribution and a sufficient heat dissipation area. However, since the fins are plate-shaped fins, air cannot be exhausted in the Y direction, the velocity vector in the Y direction disappears, and only the velocity map distribution in the X direction remains. Therefore, even in this case in which the temperature distribution is good as the heat sink structure and a sufficient surface area is secured, the velocity distribution as shown in FIG. 7 for securing a sufficient air volume cannot be obtained,
As a result, the structure is such that sufficient heat dissipation performance cannot be obtained.

The present invention solves the above problems, and provides a high-performance heat sink having improved heat radiation performance of heat generated from a heating element and a cooling device for electronic parts having excellent cooling performance using the heat sink. The purpose is to do.

[0014]

A heat sink of a cooling device according to the present invention is provided with a heat transfer plate that is in contact with a heating element and projects to the opposite side of the heat receiving surface, and is provided on the heat transfer plate along the heat receiving surface. A plurality of first slits formed and a plurality of second slits formed on the side surface of the heat transfer plate in a direction orthogonal to the heat receiving surface form a plurality of fins, and a heat sink and air are blown to the upper part of the heat sink. A cooling device having a fan as a means, wherein the second slits of the heat sink are arranged only near the both ends of the heat transfer plate immediately below the blades of the cooling fan to increase the amount of airflow that contributes to heat dissipation, thereby improving the heat dissipation characteristics. Can be increased.

The heat sink of the cooling device of the present invention comprises a heat transfer plate portion which is in contact with the heating element and diffuses heat from the heat receiving surface, and a plurality of first heat transfer plate portions which are provided on the upper surface of the heat transfer plate portion along the heat receiving surface. A heat sink having one fin and a plurality of fins formed by a plurality of second slits provided on the upper surface of the heat transfer plate so as to intersect the first slit, the heat sink comprising: It is characterized in that it has a shape in which the plate thickness in a cross section perpendicular to the heat receiving surface gradually increases from at least one to the other.

Alternatively, the heat sink of the cooling device of the present invention is provided with a heat transfer plate portion that is in contact with the heating element and that diffuses heat from the heat receiving surface, and is provided on the upper surface of the heat transfer plate portion along the heat receiving surface. A plurality of fins are formed by a plurality of first slits and a plurality of second slits provided on the upper surface of the heat transfer plate so as to intersect with the heat receiving surface. May be.

Further, in the cooling device of the present invention, a heat transfer plate portion which is in contact with the heating element and diffuses heat from the heat receiving surface, and a plurality of heat transfer plate portions are provided on the upper surface of the heat transfer plate portion along the heat receiving surface. A heat sink having a plurality of fins formed by slits, the heat sink having a shape in which a plate thickness in a cross section perpendicular to the heat receiving surface of the heat transfer plate portion gradually increases from at least one to the other; And an attached cooling means.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 is a heat transfer plate which is in contact with a heating element and projects to the opposite side of the heat receiving surface, and a plurality of heat transfer plates provided on the heat transfer plate along the heat receiving surface. Cooling provided with a heat sink in which a plurality of fins are formed by a first slit and a plurality of second slits formed in a side surface of the heat transfer plate in a direction orthogonal to the heat receiving surface, and a fan serving as a blower unit above the heat sink. In the device, by disposing the second slits of the heat sink only in the vicinity of both ends of the heat transfer plate, it is possible to increase the amount of airflow that contributes to heat dissipation and improve heat dissipation characteristics.

According to a second aspect of the present invention, the cutting depth of the second slit of the heat sink to the heat transfer plate is set to the first depth.
By making the depth shallower than the slit, it is possible to efficiently transfer heat from the heat transfer plate to the upper portion of the fin without reducing the cross-sectional area of the plate fin, and it is possible to improve the heat dissipation characteristics of the entire heat sink.

According to a third aspect of the present invention, the cross-sectional shape of the heat transfer plate is a rectangle, a trapezoid, a triangle or a substantially vertical direction from the heat receiving surface as a cross-sectional shape perpendicular to the direction along which the heat transfer plate extends along the first slit. By adopting one of the heat sink shapes in which the cross-sectional width of the heat transfer plate is gradually reduced, the heat distribution of the entire heat sink can be made uniform and the heat dissipation characteristics can be improved.

According to a fourth aspect of the present invention, the second slit is formed in the heat sink only in the vicinity of the bottom of the fan blades on both ends of the heat transfer plate, so that the exhaust gas is discharged in the second slit direction. It is possible to secure an area and increase the amount of air that contributes to heat dissipation.

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a perspective view, a front view and a side view of a main part of a cooling device according to Embodiment 1 of the present invention. FIG. 1 (a) shows cooling according to Embodiment 1 of the present invention. 1 (b) is a front view of the cooling device according to the present invention as viewed from the Y-axis direction, and FIG. 1 (c) is an X view.
It is a side view of the cooling device of the present invention seen from the axial direction.

FIG. 2 is a perspective view of a main part of the cooling device according to the first embodiment of the present invention and a velocity distribution diagram of air exhausted from the heat sink. FIG. 2 (a) is the same as FIG. 1 (a). 2 (b) is a perspective view of a main part of the cooling device according to the first embodiment of the present invention, and FIG. 2 (b) is exhausted around a heat sink when the cooling device according to the first embodiment of the present invention is viewed from the Z direction. It is explanatory drawing which showed the velocity distribution of the XY directions of air.

1 (a) to 1 (c), 1b is a plate-shaped fin formed on the upper part of the heat transfer plate 2.
Is a columnar fin formed on the upper part of the plate-shaped fin of 1b, and 1a is a plate-shaped fin extending on the upper part of the plate-shaped fin of 1b to the vicinity of the fan of the upper part with the same thickness. Reference numeral 2 denotes a heat transfer plate (that is, a heat transfer portion or a support) on which the columnar fins 1 and the plate-shaped fins 1a and 1b are arranged, and 3 is attached to a lower portion of the heat transfer plate 2 (negative Z-axis direction). It is a heating element. In this case, the heat sink is composed of columnar fins 1 and heat transfer plate 2. Here, as the heating element 3, a semiconductor such as an IC, an LSI, an MPU, or an electronic component such as a transistor generates heat.

In order to facilitate the description below, in addition to the representation of partial names as shown in FIG. 1, the length direction of the heat transfer plate 2 (support) is set to the X-axis direction as described above. , The width direction of the heat transfer plate 2 is the Y axis direction, and the height direction of the heat transfer plate 2 is the Z axis direction.

Generally, in a heat dissipation device that is in contact with a small heating element, when heat flows from the heat receiving surface into the isotropic material, it tends to diffuse with a hemispherical temperature distribution. Therefore, an ideal heat sink shape is obtained. Is considered to have the highest heat dissipation characteristics by forming a large number of heat dissipation fins in a radial direction starting from a heat transfer part having a hemispherical shape and a heat source at the center of the heat transfer part. However, in such a configuration, various problems other than the performance arise, such as a shape and a size that cannot be used in an actual shape and an extremely high manufacturing cost.

In recent miniaturized electronic devices, heat sinks which can be formed by the extrusion method in the X direction as shown in FIG. 5A have been widely used in order to suppress the cost and ensure the performance. It was Further, as described above, the conventional heat sink having the plate-shaped fins as shown in FIG. 5 has a structure in which a uniform temperature distribution can be easily obtained and a surface area required for heat dissipation can be easily secured, which is a preferable structure. There is. However, since the fins are plate-shaped fins, the fins cannot be exhausted in the Y direction, and the exhaust direction of air is limited to one direction of the X direction.
There is a problem that sufficient heat dissipation characteristics cannot be obtained.

Therefore, with respect to this problem, the cooling device adopting the structure of the heat sink according to the present invention is
It is possible to realize a small and lightweight cooling device which has excellent heat conduction and heat dissipation properties and can be used even in small electronic devices.

In the cooling device according to the first embodiment shown in FIG. 1, the heat transfer plate 2 of the heat sink has a triangular cross section in the depth direction (X-axis direction) as shown in FIG. The heat transfer plate has a shape in which the cross-sectional width gradually decreases in a substantially vertical direction from the heat receiving surface. As a result, it is possible to realize a hemispherical temperature distribution in a much larger range in the heat transfer plate than in the plate heat transfer portion of the conventional heat sink. The heat diffused from the heating element 3 is transferred from the hemispherical temperature distribution and spreads to the range of the columnar fin 1 that functions as a heat radiation fin, and if the size is the same, the heat radiation is much higher than that of the conventional heat sink. The characteristics will be obtained. Also, FIG.
As shown in (b), the second slits are concentrated near the cooling fan blades on the end side of the heat transfer plate to form the second slits, so that not only the air flow 5a in the X direction but also as shown in FIG. Y
It is possible to newly generate the directional air flow 5b, and it is possible to secure sufficient heat dissipation performance without lowering the exhaust performance as shown in FIG. 5 of the related art.

Next, FIGS. 2 (a) and 2 (b) show a perspective view of a main part of the cooling device of the present invention and a velocity distribution diagram of air exhausted from the heat sink to the outside. From FIG. 2B, by forming the second slits in the Y direction near the end of the heat transfer plate or immediately below the fan blades on the end of the heat transfer plate, the velocity distribution of FIG. Also, the exhaust direction in the Y direction is formed, and it becomes possible to increase the air volume of air that contributes to heat dissipation.

(Embodiment 2) FIG. 3 is a perspective view, a front view and a side view of a cooling device according to Embodiment 2 of the present invention, in which the heat sink of the flat heat transfer plate shown in FIG. Similarly to the above, it is another embodiment in which the second slits are formed in the vicinity of immediately below the blades of the cooling fan on the end side of the heat transfer plate.

Also in this case, a high heat dissipation performance can be expected from the standpoint of improving the exhaust performance.

(Third Embodiment) FIG. 4 is a perspective view, a front view and a side view of a cooling device according to a third embodiment of the present invention, showing a heat sink having a corrugated thin plate joined to a flat heat transfer plate. Similar to FIG. 1, it is another embodiment in the case where the second slits are formed in the vicinity of immediately below the cooling fan blades on the heat transfer plate end side.

In this case as well, a high heat dissipation performance can be expected with the same effect as in FIG.

As described above, by forming the second slits in the vicinity of the cooling fan blades on the end side of the heat transfer plate according to the present invention, the second slits are formed so as to secure a sufficient amount of air for exhaust, and thus cooling having an extremely high heat dissipation performance. It is possible to implement the device.

[0037]

The heat sink according to the first to fourth aspects of the present invention has a shape in which the plate thickness in a cross section perpendicular to the heat receiving surface of the heat transfer plate portion facing the heating element gradually increases from one to the other. By adopting it, the heat diffusion effect from the heating element is enhanced,
Furthermore, by disposing both plate fins and columnar fins on the upper surface of the heat transfer plate, a sufficient heat dissipation area is secured,
In addition, by providing the second slits in the vicinity of the cooling fan blades on the end side of the heat transfer plate to form the second slits and increasing the amount of exhaust air, it is possible to provide a cooling device for electronic components having improved heat dissipation performance and excellent cooling performance. Is possible.

[0038]

[Brief description of drawings]

FIG. 1 is a perspective view, a front view and a side view of essential parts of a cooling device according to a first embodiment of the present invention.

FIG. 2 is a perspective view of a main part of the cooling device according to the first embodiment of the present invention and a velocity distribution diagram of air exhausted from the heat sink to the outside.

FIG. 3 is a perspective view, a front view and a side view of a main part of a cooling device according to a second embodiment of the present invention.

FIG. 4 is a perspective view, a front view, and a side view of essential parts of a cooling device according to a third embodiment of the present invention.

FIG. 5 is a perspective view, a front view, and a side view of a main part of a conventional cooling device.

FIG. 6 is a perspective view of a main part of a conventional cooling device and a velocity distribution diagram of air exhausted from a heat sink to the outside.

FIG. 7 is a perspective view of a main part of a conventional cooling device including a fan and a flat plate, and a velocity distribution diagram of air exhausted from a heat sink to the outside.

[Explanation of symbols]

1 columnar fin 1a Plate-shaped fin 1b Plate-shaped fin integrated with base 2 Heat transfer plate (support) 3 heating element 4 cooling fan 5a, 5b Air flow 6a, 6b Air velocity distribution

Claims (4)

[Claims] 1. A heat transfer plate that is in contact with a heating element and projects to the side opposite to the heat receiving surface, a plurality of first slits provided on the heat transfer plate along the heat receiving surface, and the heat transfer plate. A cooling device comprising a heat sink having a plurality of fins formed by a plurality of second slits formed on the side surface of the plate in a direction orthogonal to the heat receiving surface, and a fan serving as an air blower above the heat sink. A cooling device for electronic parts, wherein the second slit of the heat sink is arranged only near both ends of the heat transfer plate. 2. The cooling device for electronic parts according to claim 1, wherein the depth of the second slit of the heat sink cut into the heat transfer plate is shallower than the depth of the first slit. 3. A cross-sectional shape of the heat transfer plate is a rectangle, a trapezoid, a triangle, or a heat transfer surface that is gradually transferred in a substantially vertical direction as a cross-sectional shape perpendicular to the direction along the first slit. The cooling device for an electronic component according to claim 1 or 2, wherein the heat plate has a heat sink shape having a cross-sectional width that is reduced. 4. The formation position of the second slit of the heat sink is arranged only in the vicinity of under the blade of the fan on both end sides of the heat transfer plate. Item 3. A cooling device for an electronic component according to Item 3.