JP2010065934A - Cooling method and cooling apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for local rapid cooling having cooling time equal to that in conventional methods practically while improving a problem wherein in conventional local cooling of a solid surface, moisture adheres to the solid surface after the cooling and the moisture may cause a failure, in particular, in electronic circuit boards etc. <P>SOLUTION: A mass of coolant comprising an aggregate of powdery bodies is brought into contact with the solid surface, and while a contact area between the mass and the solid surface is maintained practically, the mass is pressed against the solid surface, so as to achieve local rapid cooling reducing moisture absorption. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for cooling a solid surface and a cooling device used therefor.

  Conventionally, as a method of locally quenching a solid surface, there has been an aerosol can using HFC-134a or the like as a quenching agent. Since these sprayed gas, unlike solid coolants, solid surfaces having uneven surfaces could be rapidly cooled. However, HFC-134a has become an environmentally regulated substance because it is a warming substance. As a quenching agent that obtains a quenching effect equivalent to that of HFC-134a, there is generally a flammable gas quenching agent. However, since there is a risk of a fire disaster, it is not suitable particularly when cooling electronic devices while energizing them. there were.

  On the other hand, a local quenching method using carbon dioxide gas and snow dry ice injection as shown in Patent Document 1 has been proposed.

JP-A-6-1559889

  FIG. 4 shows an example of a conventional local quenching method. In the local local quenching method of the prior art, in order to directly inject a gas, a coolant, or the like as a refrigerant from the aerosol can 9 through the nozzle 8, moisture is absorbed in the atmosphere to be cooled, and the surface of the solid 7 after cooling is absorbed. Moisture was easy to adhere. For example, in the case where the solid 7 to be cooled is an electronic component, this moisture may cause a short circuit if energized during or immediately after cooling, and it is necessary to remove moisture from the surface after cooling is completed, resulting in poor productivity. It was. In addition, in the case of rapid cooling by direct injection, a large amount of cooling gas had to be injected. HFC-134a and the like are warming substances, and these large-scale injections are unfavorable work for the global environment.

  On the other hand, solid coolant, such as block or pellet dry ice, is commercially available, and the method of cooling by pressing these is because the amount of coolant released into the atmosphere is smaller than the direct injection described above. It was examined. However, cooling by directly contacting these solid coolants on the surface of the solid 7 to be cooled is uneven in the case of an electronic component having an uneven surface, so it is difficult to secure a contact area. Therefore, the cooling time cannot be as rapid as expected.

  Therefore, there has been a demand for a method capable of rapidly cooling an uneven surface without adhering moisture, and a method for releasing a warming substance into the atmosphere.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms or application examples.

[Application Example 1]
The cooling method according to this application example is a cooling method for cooling a solid, wherein a mass of a coolant composed of an aggregate of powders is brought into contact with the surface of the solid, and the mass and the surface of the solid are brought into contact with each other. The lump is pressed against the solid surface while the contact area is practically the same.

  According to this configuration, by using the above-described cooling method, moisture in the air is not absorbed to a practically negligible level, and the powder coolant is fluid and follows a rough surface as a lump. Because it can be freely deformed, the contact area with the uneven solid surface can be secured to the extent that the cooling time can be rapidly achieved, and it is pressed so that it is practically a constant contact area, so voids generated by vaporization of the coolant Can be eliminated, and the cooling effect can be stabilized.

[Application Example 2]
In the cooling method according to this application example, it is preferable that the mass of the coolant is an aggregate of powdered solid carbonic acid.

  According to this structure, since it is a solid carbonic acid, there is no flammability, and there is no fear of a fire even if it is used for cooling electronic components while energizing. Moreover, since carbon dioxide gas having a lower warming coefficient than HFC-134a is discharged, it is also effective in preventing global warming.

[Application Example 3]
The cooling device according to this application example is a cooling device used in a method of cooling a solid with an aggregate of powdered solid carbonic acid. The cooling device includes a cylindrical body and a columnar body, and the inside of the cylindrical body is The solid carbonic acid aggregate is filled, the columnar body is inserted into the cylindrical body, and the columnar body moves toward the surface of the solid, whereby the solid carbonic acid aggregate. Is pressed against the surface of the solid.

  According to this configuration, by using the cylindrical body and the columnar body described above, it is possible to easily handle the solid carbonic acid aggregate as a lump of a certain volume, and the aggregate and the solid surface The contact area can be practically the same. Since solid carbonic acid of the powder disappears due to vaporization as the cooling proceeds, voids are generated in the lump particularly in the vicinity of the solid surface, but in the device of the present application, the columnar body moves toward the surface of the solid, and the above-mentioned Since it presses so that a space | gap may be eliminated, the contact area of the said lump and the surface of the said solid can be kept practically the same, and it can cool.

[Application Example 4]
In the cooling device according to this application example, it is preferable that the cylindrical body has a cylindrical frustum shape, and a cross-sectional area of the cylindrical body decreases toward the solid surface.

  According to this configuration, by using the cylindrical frustum-shaped cylindrical body, voids generated in the lump in the vicinity of the solid surface can be further compressed and eliminated. The cooling time can be accelerated by pressing the solid carbonic acid aggregate to eliminate voids.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the drawings.

(Embodiment)
1 and 2 are schematic cross-sectional views showing the structure of the cooling device. Hereinafter, the cooling method and the structure of the cooling apparatus will be described mainly with reference to FIG.

  As shown in FIG. 1, the cylindrical body 5 is installed in the vicinity of a place to be locally cooled on the surface of the solid 4 to be cooled. The cylindrical body 5 may be preliminarily filled with a solid carbonate powder aggregate, or may be filled with a solid carbonate powder aggregate after installation.

  The solid carbon dioxide powder is prepared by blowing carbon dioxide into the atmosphere through a snow horn from a storage container of liquefied carbon dioxide (purity 99.90 vol% or more). The prepared solid carbonic acid powder is stored in a cold container to form a coolant mass 3 (solid carbon powder aggregate mass). Alternatively, the cylindrical body 5 may be placed near the snow horn outlet, and solid carbon dioxide powder may be directly filled into the cylindrical body 5 from the snow horn.

  The solid carbon dioxide powder stored in the cold container is filled into the cylindrical body 5 using a jig such as a spoon or a spatula. The filling method of the solid carbonic acid powder is not limited to the method described above. Any method that can ensure cold resistance and safety may be used. For example, cold-resistant gloves may be used for filling with human hands.

  The columnar body 6 is inserted into the cylindrical body 5 filled with solid carbonic acid powder, and the mass of coolant 3 is pressed against the solid surface while moving the columnar body 6 in the direction of the solid surface. This movement of the columnar body 6 may be performed in a timely manner so as to eliminate the gap of the coolant due to vaporization. A tapered cylindrical body as shown in FIG. 2 may be used, or a cylindrical body having substantially the same cross section as shown in FIG. 1 may be used. However, since the effect of pressing in FIG. 2 is higher, the cooling time can be stably and rapidly.

  Next, the relationship between the pressing force and the cooling time will be described.

  In FIG. 3, the temperature of the solid surface to be cooled is plotted as the elapsed time from the start of cooling. A commercially available resin circuit board was used as a solid for temperature measurement. A thermocouple K wire was attached to the surface of the resin circuit board, and the surface temperature of the resin circuit board was measured using an LR4120 manufactured by Yokogawa Electric.

  The cylindrical body 5 is a ceramic cylinder having an outer diameter of about 20 mm to 30 mm and a hollow portion having an inner diameter of about 15 mm to 20 mm. The length of the cylinder is about 30 mm. The cylindrical shape may be a cylindrical shape or a polygonal cylindrical shape. Moreover, the material of the cylindrical body 5 is not limited to ceramic, and resin, metal, or the like may be used.

  FIG. 3 shows the results obtained in the above experiment. The conditions of the results shown are 3 conditions. The solid line is the result of the condition in which the columnar body 6 presses the coolant mass 3. On the other hand, the broken line is the result of the condition in which the coolant mass 3 is not pressed by the columnar body 6. As a comparative experiment, cooling by gas injection from an aerosol can of HFC-134a is also performed, and the result of the cooling time is indicated by a two-dot chain line.

  Under the condition where the pressing is not performed (broken line), the cooling time until reaching −40 ° C. was 4 minutes, but under the pressing condition (solid line), it was shortened to 1 minute. Although it is later than 20 seconds of the HFC-134a injection condition (two-dot chain line) shown as a comparison, the pressing condition (solid line) is a practically applicable cooling time. In addition, adhesion of moisture was observed on the surface of the resin circuit board immediately after cooling only under the condition of HFC-134a injection (two-dot chain line).

  As described above, the mass of the coolant composed of the powder aggregate is brought into contact with the solid surface, and the mass is directed to the solid surface while the area where the mass is in contact with the solid surface is practically the same. By being pressed, it is cooled in a cooling time substantially equivalent to the local quenching in the conventional jet of a coolant gas or the like, and the local quenching with less moisture adhesion can be realized. It is also an environmentally friendly technology because it uses a gas with a lower global warming potential than regulated substances and emits less in the atmosphere.

The schematic cross section which shows the structure of a cooling device. The schematic cross section which shows the structure of a cooling device. The graph which shows the cooling effect of this application and HFC-134a. The schematic diagram which shows the conventional cooling method.

Explanation of symbols

  3 ... lump of coolant, 4 ... solid, 5 ... cylindrical body, 6 ... columnar body.

Claims (4)

A cooling method for cooling a solid,
A coolant mass composed of an aggregate of powders is brought into contact with the surface of the solid, and the area where the mass and the surface of the solid are in contact is practically the same, while the mass is directed toward the solid surface. A cooling method characterized by pressing.   The cooling method according to claim 1, wherein the mass of the coolant is an aggregate of powdered solid carbonic acid. A cooling device used in a method of cooling a solid with an aggregate of powdered solid carbonic acid,
It is composed of a cylindrical body and a columnar body, the mass of the solid carbonic acid aggregate is filled inside the cylindrical body, the columnar body is inserted into the cylindrical body, and the columnar body is the solid body. A cooling apparatus, wherein the solid carbonic acid aggregate is pressed against the surface of the solid by moving toward the surface of the solid.   The cooling device according to claim 3, wherein the cylindrical body has a cylindrical frustum shape, and a cross-sectional area of the cylindrical body decreases toward the solid surface.

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