JPS6011832B2 - Cooling system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a cooling device for electronic circuit components including heat generating elements such as transistors, which are cooled by boiling of cold butter.

FIG. 1 is a sectional view showing a conventional cooling device of this type, in which 1 is a closed container, 2 and 3 are a plurality of first and second liquids having different densities sealed in the closed container 1, and The density of the first liquid 2 on the side is higher than the density of the second liquid 3 on the upper side, and the boiling point of both liquids 2 and 3 is lower than that of the first liquid 2 on the lower side. It is being

Reference numeral 4 denotes an interface between the first and second liquids 2 and 3, 5 a heating element to be cooled, such as an electronic circuit component such as a transistor, and 6 a heating element formed on the upper part of the second liquid 3, which controls the temperature. This is a gas phase space provided to release the expansion of both liquids 2 and 3 as they rise.

In the conventional cooling device configured as described above, when the heating element 5 consisting of an electronic circuit component such as a transistor starts to generate heat, the first liquid 2 with which the heating element 5 is in contact
Inside, steam bubbles 7 are generated and gradually rise as shown in FIG.

Therefore, the surface of the heating element 6 is extremely efficiently cooled by the disturbance action of the first liquid 2 caused by the vapor bubbles 7 that are successively generated and separated. The rising vapor bubbles 7 then penetrate the boundary surface 4 and enter the upper second liquid 3. By forcibly cooling the outer wall surface of the closed container 1 using an electric fan (not shown), the second liquid 3 is cooled by exchanging heat with the inner wall surface of the closed container 1. Therefore, the vapor bubbles 7 that have entered the second liquid 3 are cooled by the second liquid 3 and condensed into droplets 8 as shown in FIG. In this way, since the first liquid 2 condensed in the second liquid 3, that is, the droplet 8, has a density greater than that of the second liquid 3, it penetrates the boundary surface 4 due to its own weight and drops into the first liquid. However, since the boiling point of the second liquid 3 is higher than the boiling point of the first liquid 2, no boiling occurs. As described above, in the conventional cooling device, the heat generated in the heating element 5 becomes vapor bubbles 7 of the first liquid 2 and enters the upper second liquid 3, where it is condensed. Heat is radiated into the second liquid 3, and the heat is radiated from the second liquid 3 to the outside via the wall surface of the closed container 1. However, in the second liquid 3 in the conventional cooling device described above, there are vapor bubbles 7 that enter the second liquid 3 and rise, and first liquid 2 that condenses and descends.
Since the liquid droplets 8 are mixed, there is a drawback that the effect of disturbing the second liquid 3 by the vapor bubbles 7 is reduced. That is,
The heat transfer from the second liquid 3 to the inner peripheral wall surface of the closed container 1 is as follows:
This is mainly caused by the natural S convection phenomenon, but it is clear that when the above-mentioned disturbance effect caused by the vapor bubbles 7 rising in the second liquid 3 is added to this natural convection phenomenon, the heat transfer coefficient is significantly improved. Nevertheless, in the conventional cooling device of this type, since there is no guiding device for the vapor bubbles 7, the heat transfer efficiency between the second liquid 3 and the inner circumferential wall surface of the closed container 1 is extremely poor. This invention has been made with attention to this point, and a guide device is provided to guide the vapor bubbles 7 rising in the second liquid 3 so that they rise along the inner wall surface of the closed container 1. By effectively utilizing the disturbance effect of 7, the second
This is intended to improve the heat transfer efficiency between the liquid 3 and the inner circumferential wall surface of the closed container 1.

That is, FIG. 2 shows one embodiment of this invention.
1 is an airtight container; 2 and 3 are a plurality of first and second liquids having different densities sealed in the airtight container 1; the density of the lower first liquid 2 is higher than that of the upper second liquid; The density of the lower first liquid 2 is higher than that of the liquid 3, and the boiling point of both liquids 2 and 3 is lower than that of the first liquid 2.

4 is an interface between the first and second liquids 2 and 3, 5 is a heating element made of an electronic circuit component such as a transistor, and 6 is formed above the second liquid 3, and as the temperature rises, A gas phase space 7 provided to release the expansion of both liquids 2 and 3 is generated within the first liquid 2 and penetrates through the boundary surface 4 to enter the upper second liquid 3. The vapor bubbles 8 are droplets formed by being cooled and condensed by the second liquid 3. Reference numeral 9 denotes a cup-shaped guide device that spans the first and second liquids 2 and 3 in the sealed container 1 and is disposed corresponding to the boundary surface 4 between the two liquids. A large number of relatively small-diameter holes 10 are formed in the peripheral wall to allow the droplets 8 to pass through but not to allow the vapor bubbles 7 to pass through, and in reality, a wire mesh or a perforated plate is used. This cup-shaped guide device 9 causes vapor bubbles 7 generated in the first liquid 2 near the heating element 5 to rise intensively along the inner circumferential wall surface of the closed container 1, and It is provided to return droplets 8 that have been cooled and condensed in the liquid 3 into the first liquid 2 .

As described above, according to the present invention, in the closed container 1 containing the heating element 5, the boundary surface 4 between the first and second liquids 2 and 3 having different densities and boiling points is straddled.
Since the guide device 9 is arranged in accordance with Since the second liquid 3 is guided by the guide device 9 so as to rise, the heat transfer efficiency between the second liquid 3 and the inner circumferential wall surface of the closed container 1 is significantly improved.

Therefore, it is possible not only to reduce the size of the cooling diamond of this type of electronic circuit component, but also to have an excellent effect of suppressing abnormal temperature rise of the heating element 5 made of the electronic circuit component.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a conventional cooling device, and FIG. 2 is a sectional view showing an embodiment of the present invention. In the drawings, 1 is a closed container, 2 is a first liquid, 3 is a second liquid, 4 is an interface, 5 is a heating element, 7 is a vapor bubble, 8 is a droplet,
9 is a guide device, and 10' is a small hole. Note that the same reference numerals in the figures indicate the same or corresponding parts. Figure 1 Figure 2

Claims (1)

[Scope of Claims] 1. A first liquid and a second liquid having different densities and boiling points are sealed in a closed container containing a heating element at a predetermined position, and a boundary between these liquids is straddled between the two liquids. A guide device is provided corresponding to the surface, and the guide device causes steam bubbles generated in the vicinity of the heating element to rise intensively along the inner peripheral wall surface of the closed container. Cooling device. 2. The cooling device according to claim 1, wherein the guide device is shaped like a pot and has a large number of small holes through which vapor bubbles do not pass, but liquid droplets pass through.