JPH09167819A - Heat pipe cooler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make uniform a temperature difference, which is generated between the windward side and the leeward side of a heat-receiving plate, by a method wherein more than two kinds of working fluids of different amounts of heat transmission are used as working fluids, which are respectively encapsulated in a plurality of heat pipes which are provided side by side, and the heat pipes encapsulated with these working fluids are arranged in the order of the pipe encapsulated with the working fluid of the small amount of heat transmission from the windward side of a convection. SOLUTION: A working fluid 4a is encapsulated in heat pipes 2a and 2b, a working fluid 4b is encapsulated in a heat pipe 2c and convection is caused from one side of the parallel directions of the heat pipes passing through heat dissipation fins 3. The pipes 2a to 2c are small in a heat resistance value in order from the windward side of the convection, in short, are large in the amount of heat transmission. Thereby, as the pipe 2c on the leeward side, where is decreased in the amount of the wind which strikes directly on the side, of the convection is large in the amount of heat transmission, the pipe 2c can be made a heat exchange in roughly the same way as that of the pipe 2a on the windward side and a temperature difference, which is generated between the windward side and the leeward side of a heat- receiving plate, can be decreased. Accordingly, the formation of a heat pipe cooler is easy and the life of a semiconductor element can be prolonged.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pipe cooler, and more particularly to a heat pipe cooler capable of making the temperature distribution of a heat receiving plate uniform even when cooling a heat radiating portion by convection.

[0002]

2. Description of the Related Art Conventionally, as a heat pipe cooler, for example, there is one in which a plurality of heat pipes arranged in parallel have a base portion serving as a heat receiving plate on one end side and a large number of fins for heat radiation attached on the other side. When this is used for cooling a semiconductor, for example, a semiconductor element is attached to the heat receiving plate and installed. However, in recent years, semiconductor devices have been downsized, and along with this, the heat pipe cooler must be downsized, but in the heat pipe cooler, the size is reduced and the space between the heat pipes arranged side by side is narrowed. It will be.

Cooling air by natural convection or forced convection is normally blown to the heat radiating portion of the heat pipe cooler, and the heat exchange efficiency of the heat pipe is increased to promote the cooling efficiency of the heat pipe cooler. Often configured to. However, the direction in which the cooling air is blown by the convection is considered in consideration of the arrangement, space, etc. of the entire device to which the heat pipe cooler is attached, and is blown from the parallel direction of the heat pipes or perpendicular to the parallel direction. There are various ways to blow air.

Further, in general, when a temperature distribution occurs in a semiconductor, a large amount of current flows in a low temperature portion, so that a load is locally applied and the life of the semiconductor is shortened. Therefore, uniform cooling is desired. .

Therefore, for example, Japanese Utility Model Laid-Open No. 6-50355 proposes to reduce the temperature difference between the upstream side and the downstream side of cooling air by changing the inner diameters of a plurality of heat pipes.

According to this, by increasing the inner diameter of the heat pipe from the windward side of the cooling air to the leeward side, the amount of vaporized water vapor in the heat pipe on the leeward side increases, so that the heat transport amount can be increased, Prevents decrease in heat transport,
It discloses that the temperature difference can be reduced.

[0007]

As described above, when the size of the conventional heat pipe cooler is reduced, the space between the heat pipes arranged side by side becomes narrower, so that the cooling efficiency may decrease. When the cooling air is blown from one of the heat pipes arranged in parallel in the heat pipe cooler in the parallel direction, the heat pipe on the windward side in the blowing direction is directly hit by the wind to promote cooling. However, in the heat pipe on the leeward side, the wind is hard to hit directly, and since it is in a state of being warmed by the heat pipe on the windward side in advance, the temperature of the heat pipe on the leeward side is higher than that of the heat pipe on the windward side. It will exchange heat with high air. That is, there is a problem in that the heat exchange amount of the heat pipe decreases on the leeward side, and a temperature difference occurs between the heat receiving plate on the leeward side and on the leeward side.

Furthermore, when the temperature difference is reduced by the method disclosed in Japanese Utility Model Laid-Open No. 6-50355, and when the inner and outer diameters are both changed, the size of the heat radiation fins provided in the heat pipe and the size of the holes formed in the heat receiving plate are changed. Must be done, processing takes time, and the production capacity decreases. Further, even when only the inner diameter is changed and the outer diameter is the same, it takes time and labor to process the pipe, and the production capacity is reduced. In addition, the decrease in the production capacity becomes more remarkable as the heat pipe cooler becomes smaller.

Therefore, an object of the present invention is to make the temperature difference of the heat receiving plate of the heat pipe cooler uniform and
It is to provide a heat pipe cooler that does not reduce the production capacity and can be easily downsized.

[0010]

A heat pipe cooler of the present invention comprises a plurality of heat pipes arranged in parallel, a heat receiving plate in which one end side of these heat pipes is embedded, and a plurality of heat pipes inserted in the other end side. A heat pipe cooler comprising a number of heat radiating fins, wherein when convection occurs from one of the heat pipes in the parallel direction, the working liquid is sealed in each of the plurality of heat pipes arranged in parallel. It is characterized in that two or more kinds having different heat transport amounts are used, and the heat pipes in which these working fluids are enclosed are arranged in the ascending order of heat transport amount from the windward side of the convection.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail. FIG. 1 is a view showing an embodiment of the heat pipe cooler of the present invention. In this embodiment, the heat pipe 2
It shows a mode in which one end side of a, 2b, 2c is embedded in the heat receiving plate 1 and the radiation fins 3, 3, ... Are inserted in the other end side, and the arrows in the figure indicate the direction of convection. . Fluorinert FX-3250 (Sumitomo 3M, trade name) is filled in the heat pipes 2a and 2b as the working fluid 4a, and water is filled in the heat pipe 2c as the working fluid 4b.

The shape and material of the heat receiving plate 1 are not particularly limited, and the shape can be appropriately determined according to the shape of the object to be cooled, and the material can also be determined according to the usage environment and the like. In order to effectively receive heat, it is preferable that the thermal conductivity is high and the wall thickness is thin. For example, a copper plate and an aluminum plate are preferable.

The containers for the heat pipes 2a, 2b and 2c have a high thermal conductivity and a thin wall in order to effectively transfer heat, and the corrosion due to the working fluid to be enclosed and the internal pressure It can be appropriately determined in consideration of the pressure resistance against the above. A copper pipe or the like is preferably used.

The radiating fin 3 is not particularly limited, and a thin plate of aluminum or copper, for example, may be used, and the material, shape, fin interval, etc. may be appropriately determined in consideration of heat radiation efficiency.

The working fluids 4a and 4b are not limited to the above-mentioned Fluorinert FX-3250 and water, but it is sufficient that the heat pipes enclosing the working fluid can be arranged in the ascending order of heat transfer amount from the windward side. It can be appropriately determined according to the operating temperature of the vessel, the working fluid in other heat pipes, the compatibility of the working fluid with the container (problem of corrosion, etc.), for example, various fluorinates, methanol, ethanol, and other fluorocarbon materials such as R-22, R-13
4a (all are DuPont, trade names) and the like can be appropriately combined and used.

In the present embodiment, the case where convection from the left to the right in the drawing, that is, the case where the cooling air flows, is taken into consideration, and operation is performed so that the heat transport amount of the heat pipe is larger on the right side than on the left side. The type of liquid is changed and enclosed. With this configuration, the heat pipe on the leeward side (right side in the figure) receives less direct air, and the air warmed by the heat pipe on the upwind side hits, so the heat exchange efficiency decreases, but Since the amount of transportation is larger in the heat pipe on the leeward side, the decrease in efficiency can be compensated by the increase in the amount of transportation. Therefore, the leeward heat pipe and the leeward heat pipe can exchange heat almost in the same manner, and the temperature difference between the heat receiving plates can be reduced.

Further, in the present embodiment, the case where the number of heat pipes is three is shown, but the present invention is not limited to this and can be appropriately determined according to the cooling capacity required for the heat pipe cooler.

Also, regarding the heat pipe, in the present embodiment, different kinds of hydraulic fluids are enclosed only on the most leeward side of the three pipes, but the present invention is not limited to this, and the heat transport amount of the heat pipe is on the windward side. It is sufficient if they can be arranged in ascending order. Furthermore, it is preferable to arrange the heat pipes one by one in order from the windward side so that the heat transport amount increases, because the whole heat receiving plate can be made more uniform.

[0019]

EXAMPLES Specific examples will be described below. In this example, the heat pipe cooler shown in FIG. 1 was manufactured. The heat receiving plate 1 made of an aluminum plate, the heat pipes 2a, 2b, 2c having the same shape made of a copper pipe, and the heat radiation fins 3 made of an aluminum plate are shown. And heat pipe 2
Fluorinert FX-3 as hydraulic fluid 4a in a and 2b
Water is sealed in the heat pipe 250 as a hydraulic fluid 4b. The arrows in the figure represent the direction of the flow of air blown by a fan (not shown), and the heat-dissipating fins 3, 3, ... Convection is occurring.

FIG. 2 shows the three heat pipes 2a and 2
It is the figure which showed the thermal resistance value of b, 2c. In this way, the heat resistance values of the heat pipes 2a, 2b, and 2c are sequentially small from the windward side, that is, the heat transport amount is large.

With this structure, even if air is blown as shown by the arrow in the figure, the heat pipe 2c on the leeward side, where the air blown directly decreases, has a large amount of heat transport, so that the heat pipe 2a on the windward side is The heat exchange was possible almost in the same manner, and the temperature difference between the windward side and the leeward side of the heat receiving plate could be reduced.

Further, since the heat pipes 2a, 2b, 2c are all of the same shape, the heat receiving plate 1 and the radiation fins 3 are drilled, and the heat pipes 2a, 2c are formed.
Processing of b and 2c can be performed in the same manner as in the past, and the production capacity was not reduced.

[0023]

As described above, according to the heat pipe cooler of the present invention, the temperature difference of the heat receiving plate can be reduced without reducing the production capacity of the heat pipe cooler. Therefore, it is easy to manufacture and has an excellent effect that the life of the semiconductor element can be extended.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a heat pipe cooler of the present invention.

FIG. 2 is a diagram showing a thermal resistance value of each heat pipe of the present invention.

[Explanation of symbols]

 1 Heat receiving plate 2a, 2b, 2c Heat pipe 3 Radiating fin 4a Fluorinert 4b Water

Claims (1)

[Claims] 1. A heat pipe cooler comprising a plurality of heat pipes arranged in parallel, a heat receiving plate in which one end side of these heat pipes is buried, and a plurality of heat radiation fins inserted in the other end side. Then, in the case where convection occurs from one of the heat pipes in the parallel direction, two or more types of working fluid having different heat transport amounts are used as the working liquids sealed in the plurality of heat pipes arranged in parallel, A heat pipe cooler characterized by arranging heat pipes in which these working fluids are enclosed in order of increasing heat transport amount from the windward side of the convection.