JPH08172285A - Cooling plate and cooling device - Google Patents

Abstract

PURPOSE: To obtain a cooling plate which can increase the cooling efficiency of a heat pipe although its area is small. CONSTITUTION: A cooling plate 9 is attached, so as to be freely detachable, to a heat-dissipating part 7 for a heat pipe 5 which is installed to cool a heat- generating body on a printed-circuit board. A flow passage 8 which makes a liquid 10 flow is formed at the inside of the cooling plate 9, and the liquid 10 is made to flow to the flow passage 8 so as to cool the heat-dissipating part for the heat pipe. The flow passage 8 is constituted of a parallel passage which is provided with a plurality of branch pipes 11 which branch the liquid 10 so as to flow in parallel, with a distribution main pipe 13 which is connected to an external supply pipe 12 and by which the liquid 10 supplied from the external supply pipe 12 is distributed to the plurality of branch pipes 11 and with a gathering main pipe 15 by which the liquid 10 flowing out from the plurality of branch pipes 11 is gathered so as to be discharged to an external discharge pipe 14. It is preferable that the ratio (d)/D of the diameter D of the distribution main pipe 13 and the gathering main pipe to the diameter (d) of the branch pipes is set at 0.2 or lower.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cooling plate for cooling a heat radiating portion of a heat pipe and a cooling device using the same, and more particularly to a cooling plate having improved cooling efficiency.

[0002]

2. Description of the Related Art Generally, an electronic device is composed of a large number of printed circuit boards, but it needs to be cooled because it generates heat. As a means for cooling the heating element on such a printed circuit board, a liquid cooling type in which a liquid is introduced onto the printed circuit board for cooling is considered. This is as shown in FIG.
The cooling plate 3 having the flow path 2 formed on the printed circuit board 1 is brought into close contact, and the cooling liquid sent from the outside through the coupler 4 from the outside is caused to flow into the flow path 2 to release the heat generated in the printed circuit board 1. It is something to do. However, the liquid cooling type cooling device has the following drawbacks.

(1) A coupler is inserted and removed to connect the passage of the heat sink attached to the substrate and the external pipe, but at this time, even if the liquid is removed from the pipe and the passage, it cannot be completely removed. Since the liquid used last time remains in the pipes and flow paths, some liquid leakage cannot be avoided.

(2) In order to connect the passages of the heat sink attached to a large number of boards to the external pipes, it is necessary to mount one coupler at a time, but the number of printed boards increases. As a result, the number of couplers also increases, which is troublesome and there is a risk of forgetting to mount the couplers. In particular, when the printed circuit board is a double-sided mounting type, the number of couplers is doubled, which further increases the risk. If you forget to install the coupler, the heating element will become hot and break, or liquid will spout and cause a serious accident.

(3) Since liquid is flowing through the heat sink attached to the substrate, it is difficult to deal with liquid leakage.

Therefore, a cooling device adopting a heat pipe system without the above-mentioned drawbacks is also considered. As shown in FIG. 3, in order to cool the heating element on the printed circuit board 1, the heat receiving part 6 of the heat pipe 5 is brought into close contact with the printed circuit board 1, and the heat radiating part 7 of the heat pipe 5 flows inside. The cooling plate 9 having the passage 8 formed therein is detachably attached, and the liquid 10 is caused to flow so as to be folded back by the cooling plate 9 to cool the heat radiating portion 7 of the heat pipe 5. According to this, since it is only necessary to attach / detach the cooling plate 9 to / from the heat pipe 5, attachment / detachment is easy at the time of exchanging the printed circuit board, and since the channel 8 of the cooling plate 9 is closed, there is no risk of liquid leakage. .

[0007]

By the way, in the case of adopting the heat pipe system as described above, in order to efficiently dissipate the heat received from the printed circuit board in a relatively small area, the cooling attached to the heat radiating portion of the heat pipe. The flow path structure of the plate is important. As a flow channel structure, it is conceivable to form one meandering channel in the cooling plate in order to increase the flow channel area.

However, when the meandering path is used, the curvature at the turning point becomes very small, resulting in a large pressure loss. In order to reduce the loss, it is sufficient to draw the curved portion in a gentle arc, but this requires a large area and the heat pipe mounting portion must also be enlarged. Due to the miniaturization of electronic devices, the space between printed circuit boards and the space around them are becoming less available, so miniaturization is essential.

An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to effectively cool a cooling plate and a printed circuit board which are small in size and can improve the cooling efficiency of the heat pipe, through the heat pipe. It is to provide a cooling device capable of performing.

[0010]

A cooling plate of the present invention is detachably attached to a heat radiating portion of a heat pipe provided for cooling a heating element on a printed circuit board, and a liquid is formed in a channel formed inside. In the cooling plate that flows to cool the heat dissipation portion of the heat pipe, the flow path collects the plurality of branch pipes for flowing the liquid, the distribution main pipe for distributing the liquid to the plurality of branch pipes, and the liquid flowing out from the plurality of branch pipes. It is composed of a parallel path with a collecting main pipe.

A plurality of flow passages including the branch pipe, the distribution main pipe, and the collecting main pipe may be connected in series or in parallel in order to increase the flow passage area.

In the cooling plate of the present invention, the cooling pipe is detachably attached to the heat radiating portion of the heat pipe provided to cool the heating element on the printed circuit board, and the liquid is formed in the flow passage formed inside the cooling pipe. In a cooling device for cooling the heat radiating portion of a heat pipe, a plurality of branch pipes for flowing a liquid, a distribution main pipe for distributing the liquid to the plurality of branch pipes, It is composed of a parallel path with a collecting main pipe for collecting the liquid flowing out from the branch pipe.

In order to make the resistance of the branch pipe uniform, the ratio d / D of the pipe diameter D of the main pipe and the pipe diameter d of the branch pipe is 0.2.
It is preferable to set the following.

[0014]

If the flow path of the cooling plate is not a meandering path but a parallel path having a plurality of branch pipes, the flow path resistance can be reduced even in a small area, the pressure loss is small, and the cooling efficiency is improved. be able to.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical sectional view of the cooling plate of this embodiment.

The cooling plate 9 is detachably attached to the heat radiating portion 7 of the planar heat pipe 5 provided for cooling the heating element on the printed circuit board. The attachment is arbitrary, such as screwing or clasping. Cooling plate 9
Since it is attached to a narrow space on the extension between printed circuit boards, it is composed of a thin plate-shaped body. A flow path 8 for flowing a liquid 10 such as cooling water is formed inside the cooling plate 9, and the liquid 10 is caused to flow through the flow path 8 to cool the heat dissipation portion 7 of the heat pipe 5. .

The flow path 8 of the cooling plate 9 has the liquid 10
A plurality of branch pipes 11 for branching and flowing in parallel, a main distribution pipe 13 connected to the external supply pipe 12 for distributing the liquid 10 supplied from the external supply pipe 12 to the plurality of branch pipes 11, and a plurality of the branch pipes 11 The liquid 10 that has flowed out is collected, and the external discharge pipe 1
4 and a collecting main pipe 15 for discharging to 4 and a parallel path. It is preferable that all of the distribution main pipe 13, the branch pipes 11 and the collecting main pipe 15 are straight so as not to increase the flow path resistance. The external supply pipe 12 and the external discharge pipe 14 are attached to the same side surface of the cooling plate 9, and these are integrally connected to the distribution main pipe 13, the collecting main pipe 15 of the cooling plate 9 by screwing means, etc., There are no leaks. Since the flow path 8 in the cooling plate 9 is closed to the heat pipe 5, the cooling plate 9 is connected to the heat pipe 5.
The liquid 10 does not leak when it is attached to or detached from the heat dissipation part 7.

In order to form the cooling plate as described above, two plate pieces made of aluminum or copper are respectively formed with the groove patterns forming the above-mentioned parallel paths, and these are bonded to each other, or a mold is formed. It is also made by casting (die casting).

The flow passage 8 may be formed by connecting a plurality of the above-mentioned parallel passages in series or in parallel to further enhance the cooling efficiency. For example, as shown in FIG. 2, the first-stage collecting main pipe 15 and the second-stage distribution main pipe 13 can be connected to form a two-stage series connection. Assembly pipe 15 and distribution pipe 1
3 is preferably connected by a straight line for the above reason. In this embodiment, the external supply pipe 12 and the external discharge pipe 14 are connected to the facing surfaces of the cooling plate 9, but they may be connected to the same surface.

1 and 2, the ratio d / D between the diameter D of the distribution main pipe 13 and the collecting main pipe 15 and the diameter d of the branch pipe 11 is 0.
It should be set to 2 or less. By doing this, each branch pipe 1
The resistance of No. 1 becomes uniform, the flow rate of the liquid flowing in each branch pipe 11 becomes uniform, and the cooling in the heat radiating portion of the heat pipe becomes uniform.

According to this embodiment, since the flow passage is formed by the parallel passage having a plurality of branch pipes, it is possible to construct a cooling plate having a small area and high cooling efficiency. This is particularly useful when high cooling efficiency is required, especially when the space between the printed circuit boards is small and there is no margin in the periphery. Also, when the heat generation amount of the printed circuit board changes and it is necessary to change the heat radiation amount of the heat pipe, the cooling efficiency is determined by the pattern of the parallel paths if the flow rate of the cooling plate is constant.
It can be easily dealt with by changing the pattern of the parallel paths. Further, the cooling efficiency can be changed by the contact area between the heat pipe and the cooling plate.

[0022]

According to the present invention, since the flow paths of the cooling plate are parallel paths, the flow path resistance can be reduced while the area is small compared with the case of using a meandering path, and the heat pipe The cooling efficiency can be increased.

Further, in the cooling device in which the cooling plate is attached to the heat dissipation plate of the heat pipe, the heat generated in the printed circuit board can be efficiently dissipated from the cooling plate via the heat pipe. Can cool effectively.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a cooling plate according to an exemplary embodiment of the present invention.

FIG. 2 is a vertical sectional view of a cooling plate according to another embodiment.

FIG. 3 is a front view showing an embodiment of a heat pipe type cooling device of the present invention.

FIG. 4 is a front view of a conventional liquid cooling type cooling device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Printed circuit board 5 Heat pipe 7 Heat dissipation part 8 Flow path 9 Cooling plate 10 Liquid 11 Branch pipe 13 Distribution main pipe 15 Assembly main pipe

Claims (4)

[Claims] 1. A cooling system, which is detachably attached to a heat radiating portion of a heat pipe provided to cool a heat generating element on a printed circuit board, and which allows a liquid to flow through a channel formed inside to cool the heat radiating portion of the heat pipe. In the plate, the flow path is configured by a parallel path including a plurality of branch pipes for flowing a liquid, a distribution main pipe for distributing the liquid to the plurality of branch pipes, and a collecting main pipe for collecting the liquid flowing out from the plurality of branch pipes. A cooling plate characterized in that. 2. A cooling system, which is detachably attached to a heat radiating section of a heat pipe provided for cooling a heat generating element on a printed circuit board, and which cools the heat radiating section of the heat pipe by flowing a liquid through a flow path formed inside. In the plate, the flow path is configured by a parallel path including a plurality of branch pipes for flowing a liquid, a distribution main pipe for distributing the liquid to the plurality of branch pipes, and a collecting main pipe for collecting the liquid flowing out from the plurality of branch pipes. A cooling plate comprising a plurality of the parallel paths connected in series or in parallel. 3. A heat radiating portion of a heat pipe provided for cooling a heat generating element on a printed circuit board is detachably attached to a heat radiating portion of the heat pipe, and a liquid is caused to flow through a flow passage formed inside the cooling pipe to radiate the heat from the heat pipe. In a cooling device for cooling a portion, a flow path formed inside the cooling pipe is provided with a plurality of branch pipes for flowing a liquid, a distribution main pipe for distributing the liquid to the plurality of branch pipes, and a liquid flowing out from the plurality of branch pipes. A cooling device comprising a parallel path having a collecting main pipe. 4. The diameter D of the main pipe and the diameter d of the branch pipe.
The cooling plate according to claim 1 or 2, or the cooling device according to claim 3, characterized in that a ratio d / D of the cooling plate is set to 0.2 or less.