JP2008060175A - Electronic equipment and cooling method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means for supplying a refrigerant from the outside, to provide electronic equipment having high cooling performance utilizing evaporation latent heat, and to provide a cooling method of the electronic equipment. <P>SOLUTION: In the cooling method, an electrical heating element, such as a semiconductor chip 1, and a water storage region 22 having a water absorption material or a hygroscopic material 23 are changed into vapor 27 by thermally connecting at least one portion of the water storage region to the electrical heating element and evaporating moisture, and the periphery is cooled by the latent heat. The electronic equipment has the electrical heating element in a casing, and the water storage region having a water absorption material or a hygroscopic material. A ventilation duct 25 for discharging vapor to the outside is provided in the casing. The upper and lower portions of the moisture absorption material or the hygroscopic material 23 are sandwiched by a moisture-permeable sheet 24 that permeates gas but does not liquid. The vapor that has absorbed heat with excessive evaporation latent heat can be discharged as it is, thus realizing the electronic equipment having high cooling performance. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for cooling an electronic device such as a mobile phone.

Since the semiconductor chip (semiconductor element) runs away when the temperature rises, the semiconductor chip (semiconductor element) is controlled below a specified temperature at which it operates safely. Particularly in a highly exothermic semiconductor chip, heat is dissipated by mounting a heat spreader, heat sink heat pipe, fan, etc. on an electronic device.
Some products also use water cooling technology. The heat pipe absorbs heat by the latent heat of evaporation of the internal refrigerant, and supplies the liquid again to the evaporation section by the capillary force of the wick. Although it has a high heat transport capability, it is not cooled, and a heat radiating fin or the like is required in the condensing part. If the steam that has absorbed heat by the latent heat of vaporization is exhausted as it is, high cooling performance can be realized without using heat radiation fins. However, since there is no means for continuing to supply the refrigerant, such cooling is not realized in electronic devices.

Patent Document 1 discloses a small element cooling device having a high cooling capacity and a heating element having a high cooling capacity. The element cooling device is formed by holding a hygroscopic agent on a hygroscopic agent holding body fixed to the heat generating element. The hygroscopic agent absorbs and retains surrounding moisture due to the hygroscopic effect when the heat generation amount of the heat generating element is small and the temperature is low. The retained moisture evaporates (dry state) when the heating value of the heating element increases and the temperature rises, and suppresses the temperature rise of the heating element due to the heat of vaporization when it evaporates. The element cooling device in the dry state absorbs the surrounding water when the amount of heat generated by the heat generating element decreases again, and becomes moisturized to prepare for the temperature rise of the heat generating element.
JP 2004-319713 A

  The present invention provides means for supplying a refrigerant from the outside, thereby providing an electronic device having high cooling performance utilizing latent heat of vaporization and a method for cooling the electronic device.

One aspect of the electronic device cooling method of the present invention includes a heating element and a water storage region having a moisture absorbing material or a water absorbing material, and at least a part of the water storage region is thermally connected to the heating element to evaporate. Cooling is performed by latent heat, and at least a part of the hygroscopic material is covered with a moisture permeable sheet made of a film that transmits gas and does not allow liquid to pass through, and at least one of the water storage regions that are thermally connected to the heating element. The section is characterized in that the water in the water storage region is moved onto the heating element by capillary force.
According to another aspect of the electronic device of the present invention, a housing that stores the electronic device, a heating element that is stored in the electronic device, and a water storage region that includes a hygroscopic material or a water absorbing material that is stored in the electronic device. At least a part of the water storage region is thermally connected to the heating element, and cools the heating element by latent heat of vaporization, and at least a part of the moisture absorbing material or the water absorbing material transmits gas and allows liquid to pass through. At least a part of the water storage region that is covered with a moisture permeable sheet made of a non-membrane and thermally connected to the heating element moves moisture of the water storage region onto the heating element by capillary force. It is said.

  According to the present invention, since the steam having absorbed heat by the latent heat of vaporization is exhausted as it is, an electronic device having high cooling performance can be realized.

  Hereinafter, embodiments of the invention will be described with reference to examples.

First, Embodiment 1 will be described with reference to FIGS.
1 and 2 are cross-sectional views of main parts of an electronic device for explaining a method for cooling the electronic device of this embodiment.
In this embodiment, a heating element, for example, a water storage region having a hygroscopic or water-absorbing substance (hereinafter referred to as a hygroscopic material or a water absorbing material) is arranged inside a housing in which a semiconductor chip is housed, Collects moisture from the outside obtained by human breath, sweat, water injection, fuel cell drainage, etc., and supplies the moisture directly to the heating element (heating source) such as a semiconductor chip or using capillary force by wick. Cooling by latent heat of evaporation.

  The water absorbing material is a material that absorbs water and holds the absorbed water (liquid). The hygroscopic material is a material that absorbs moisture and retains moisture (gas). As the water absorbing material, there is a highly water absorbent resin. It has a water retention of several hundred to a thousand times its own volume. Examples of the water-absorbing material include fibers such as paper, sponge, and cloth. The water retention amount is several to several tens of times its own volume. Since the feature of the present invention utilizes the latent heat of vaporization of the water present in the water storage region, the moisture absorbent used here needs to liquefy the moisture in the atmosphere after absorbing moisture (so-called deliquescence). As such a deliquescent hygroscopic material, potassium chloride and magnesium chloride are known. In addition, silica gel, lime, synthetic zeolite, and ion exchange resin are known as hygroscopic materials, but there is no deliquescence. The highly water-absorbent resin is a polymer that has the property of absorbing water to swell and gelling the entire water, and includes starch, carboxymethyl cellulose, polyacrylic acid, and poval. N-isopropylacrylamide whose water retention amount varies with temperature is also a superabsorbent resin.

  The moisture absorption rate is a JIS standard value, the moisture absorption at a relative humidity of 20% is 8.0%, the moisture absorption at a relative humidity of 50% is 22.0%, and the moisture absorption at a relative humidity of 90%. There is a standard that the degree is 30%. Silica gel type A is 10%, 24% and 34%. Calcium chloride has 3-5 times the performance of silica gel. In the present invention, it is preferable that the moisture absorbing material has a moisture absorption of 8.0% or more at a relative humidity of 20%, and the water retention amount of the water absorbing material is several times or more of its own volume.

As shown in FIG. 1, a semiconductor chip 1 as a heating element is housed in a housing (not shown) of an electronic device such as a mobile phone. The water storage area 2 is mounted on the semiconductor chip 1. The water storage region 2 is composed of a hygroscopic material or water absorbing material 3 and a membrane 4 (hereinafter referred to as a moisture permeable sheet) 4 which sandwiches the hygroscopic material or water absorbing material 3 from above and below and does not allow liquid to pass through. That is, the moisture-permeable sheet 4 has a structure that does not leak.
The moisture absorbing material 3 or the water absorbing material 3 inside the water storage region 2 is in contact with external air through the moisture permeable sheet 4 and the like and constantly absorbs moisture (FIG. 1 (a)). The water storage region 2 is thermally connected to the semiconductor chip 1 that is a heating element via a moisture permeable sheet 4. Then, the moisture supplied onto the semiconductor chip 1 that is a heating element is heated by the semiconductor chip 1 and evaporated, thereby depriving the semiconductor chip 1 of heat by the latent heat of vaporization.

In this embodiment, since the high cooling performance due to the latent heat of vaporization can be used, the cooling system can be made thinner than that using the radiation fins. Further, this embodiment can reduce the air volume of the fan, and low noise and power consumption effects can be expected.
FIG. 2 shows another example of this embodiment. This example is characterized in that a metal layer that does not allow liquid to pass is interposed between the semiconductor chip and the moisture absorbing material or the water absorbing material instead of the moisture permeable sheet. As in FIG. 1, a semiconductor chip 1 that is a heating element is housed in a housing (not shown) of an electronic device such as a mobile phone, and a water storage region 2 is mounted on the semiconductor chip 1. The water storage area 2 has a moisture absorbing material or water absorbing material 3, a metal case 5 that houses the moisture absorbing material or water absorbing material 3, and gas that covers the surface of the moisture absorbing material or water absorbing material 3 inside the metal case 5 is permeated and liquid does not pass therethrough. The moisture permeable sheet 4 is comprised.

Such a hygroscopic material or water absorbent 3 in the water storage region 2 is in contact with external air through the moisture permeable sheet 4 and the like, and constantly absorbs moisture (FIG. 2A). The water storage region 2 is thermally connected to the semiconductor chip 1 via a metal case 5. Then, the moisture supplied onto the semiconductor chip 1 is heated by the semiconductor chip 1 and evaporates, thereby cooling the semiconductor chip 1 by removing heat from the surroundings by latent heat of vaporization (FIG. 2B). The metal case 5 can sufficiently prevent liquid leakage.
As described above, in this embodiment, since the steam that has absorbed heat by the latent heat of vaporization is exhausted as it is, an electronic device having high cooling performance can be realized.

Next, Example 2 will be described with reference to FIG.
FIG. 3 is a cross-sectional view of the main part of the electronic device for explaining the cooling method of the electronic device of this embodiment. This embodiment is characterized in that it has a duct, the water storage area is close to the heating element, and a part thereof is placed on the heating element.
In this embodiment, a heat storage element, for example, a water storage region having a moisture absorbing material or a water absorbing material is arranged inside a housing in which a semiconductor chip is stored, and moisture from the outside is collected, and the heat generating element such as a semiconductor chip is placed on the heating element. Cooling by latent heat of vaporization.

As shown in FIG. 3A, a semiconductor chip 21 as a heating element is housed in a housing (not shown) of an electronic device such as a mobile phone. The water storage region 22 is disposed in the vicinity of the semiconductor chip 21, and a part thereof is placed on the semiconductor chip 21. The water storage region 22 includes a moisture absorbent material or a water absorbent material 23 and a moisture permeable sheet 24 that covers the moisture absorbent material or the water absorbent material 23 and allows gas to pass therethrough and liquid not to pass therethrough. And the water storage area | region 22 is in contact with the ventilation duct 25 arrange | positioned in a housing | casing.
The moisture absorbing material or the water absorbing material 23 in the water storage region 22 is in contact with the external air through the moisture permeable sheet 24 and constantly absorbs moisture 26 to accumulate moisture. The water storage region 22 is thermally connected to the semiconductor chip 21 via a moisture permeable sheet 24. The moisture supplied onto the semiconductor chip 21 evaporates due to the heat generated by the semiconductor chip 21 to become vapor, and cools the semiconductor chip 21 by removing heat from the surroundings by latent heat of evaporation. The steam that has cooled the semiconductor chip 21 is discharged from the ventilation duct 25 to the outside. As the moisture supplied to the moisture absorbent material or the water absorbent material 23, breath, sweat, water collected from the fuel cell, and the like can be used in addition to the atmosphere.

FIG. 3B is another example of this embodiment, and the configuration differs from the electronic device of FIG. 3A in that a wick is used in the water storage area. As shown in the figure, a semiconductor chip 21 as a heating element is housed in a housing (not shown) of an electronic device such as a mobile phone. The water storage area 22 is disposed in the vicinity of the semiconductor chip 21.
The water storage region 22 is formed on the moisture absorbing material or the water absorbing material 23, the moisture permeable sheet 24 that covers the moisture absorbing material or the water absorbing material 23, allows gas to pass therethrough and does not allow liquid to pass therethrough, and the semiconductor chip 21. The material 23 is composed of a wick 28 having a capillary force connected to the material 23. The wick 28 guides the water retained in the moisture absorbing material or the water absorbing material 23 onto the semiconductor chip 21 by capillary force. And the water storage area | region 22 is in contact with the ventilation duct 25 arrange | positioned in a housing | casing.
It is thermally connected to the semiconductor chip 21 via a moisture permeable sheet 24. The moisture supplied onto the semiconductor chip 21 by the wick 28 evaporates due to the heat generated by the semiconductor chip 21 to become vapor, and cools the semiconductor chip 21 by removing heat from the surroundings by latent heat of evaporation. The moisture supplied to the hygroscopic material or the water absorbing material 23 can be breath, sweat, water collected from the fuel cell, or the like, in addition to being obtained from the atmosphere.

  In this embodiment, since the high cooling performance due to the latent heat of vaporization can be used, the cooling system can be made thinner than that using the radiation fins. In addition, the fan air volume can be reduced, and low noise and power consumption effects can be expected. In this way, since the steam that has absorbed heat by the latent heat of vaporization is exhausted as it is, an electronic device having high cooling performance can be realized.

Next, Example 3 will be described with reference to FIG.
FIG. 4 is a cross-sectional view of the main part of the electronic device for explaining the cooling method of the electronic device of this embodiment. This embodiment is characterized by having a duct to which a fan is attached, the water storage area being close to the heating element, and a part of which is placed on the heating element.
In this embodiment, a heat storage element, for example, a water storage region having a moisture absorbing material or a water absorbing material is arranged inside a housing in which a semiconductor chip is stored, and moisture from the outside is collected, and the heat generating element such as a semiconductor chip is placed on the heating element. Cooling by latent heat of vaporization.

As shown in FIG. 4A, a semiconductor chip 31 as a heating element is housed in a housing (not shown) of an electronic device such as a mobile phone. The water storage area 32 is disposed close to the semiconductor chip 31, and a part thereof is placed on the semiconductor chip 31. The water storage area 32 is composed of a hygroscopic material or water absorbing material 33 and a moisture permeable sheet 34 that covers the hygroscopic material or water absorbing material 33 and that allows gas to pass therethrough and liquids not to pass therethrough. And the water storage area | region 32 is in contact with the ventilation duct 35 arrange | positioned in a housing | casing. A fan 39 is attached to one end of the ventilation duct 35.
The moisture absorbing material 33 or the water absorbing material 33 in the water storage region 32 is in contact with the external air through the moisture permeable sheet 34, and constantly absorbs moisture 36 to accumulate moisture. The water storage region 32 is thermally connected to the semiconductor chip 31 via a moisture permeable sheet 34. The moisture supplied onto the semiconductor chip 31 evaporates due to the heat generated by the semiconductor chip 31 and becomes vapor, and cools the semiconductor chip 31 by removing heat from the surroundings by latent heat of evaporation. The steam that has cooled the semiconductor chip is discharged from the ventilation duct 35 to the outside. Since the fan 39 is attached to the ventilation duct 35, discharge | emission of the vapor | steam outside can be accelerated | stimulated and a cooling effect is improved. The moisture supplied to the hygroscopic material or the water absorbing material 33 can use breath, sweat, water collected from the fuel cell, etc. in addition to the air.

FIG. 4B is another example of this embodiment, and the configuration is different from the electronic device of FIG. 3A in that a wick is used in the water storage area. A semiconductor chip 31 as a heating element is housed in a housing (not shown) of an electronic device such as a mobile phone. The water storage area 32 is disposed in the vicinity of the semiconductor chip 31.
The water storage region 32 is formed on the semiconductor chip 31 and the moisture absorbing material or water absorbing material 33, the moisture absorbing material 33, the moisture absorbing material 33 that covers the moisture absorbing material or the water absorbing material 33, and the moisture permeable sheet 34 that allows gas to pass therethrough but does not allow liquid to pass through. The material 33 is composed of a wick 38 having a capillary force connected thereto. The wick 38 guides the water retained in the moisture absorbing material or the water absorbing material 33 onto the semiconductor chip 31 by capillary force. And the water storage area | region 32 is arrange | positioned in a housing | casing, and is in contact with the ventilation duct 35 to which the fan 39 was attached.
It is thermally connected to the semiconductor chip 31 via a moisture permeable sheet 34. The moisture supplied by the wick 38 onto the semiconductor chip 31 evaporates as a result of the heat generated by the semiconductor chip 31 and becomes vapor, and the semiconductor chip 31 is cooled by removing heat from the surroundings due to latent heat of evaporation. The moisture supplied to the hygroscopic material or the water absorbing material 33 can be breath, sweat, water collected from the fuel cell, or the like, in addition to being obtained from the atmosphere.

  In this embodiment, since the high cooling performance due to the latent heat of vaporization can be used, the cooling system can be made thinner than that using the radiation fins. Moreover, since the fan 39 is attached to the ventilation duct 35, discharge | emission of a vapor | steam outside can be accelerated | stimulated and a cooling effect is improved. In this way, since the steam that has absorbed heat by the latent heat of vaporization is exhausted as it is, an electronic device having high cooling performance can be realized.

Next, Example 4 will be described with reference to FIG.
FIG. 5 is a cross-sectional view of a mobile phone which is an electronic apparatus of this embodiment.
In this embodiment, a heat storage element, for example, a water storage region having a moisture absorbing material or a water absorbing material is arranged inside a housing in which a semiconductor chip is stored, and moisture from the outside is collected, and the heat generating element such as a semiconductor chip is placed on the heating element. Cooling by latent heat of vaporization.

  A ventilation duct 45 having a microphone 49, a semiconductor chip 41, a water storage area 42, and a fan 47 through which air is passed is formed and arranged in the housing 40 of the mobile phone. The water storage area 42 is formed on the hygroscopic material or water absorbing material 43 close to the semiconductor chip 41, the hygroscopic material or water absorbing material 44 close to the microphone 49, and the semiconductor chip 41. A wick 48 to be supplied to the chip 41 is provided. In addition, an opening 46 is formed at a position of the housing 40 close to the moisture absorbing material or the water absorbing material 43. The moisture absorbing material or the water absorbing material 43 is exposed at the opening 46 via a moisture permeable sheet (not shown). Then, moisture is absorbed from the outside through water injection or sweat. Thus, the moisture absorbing material or the water absorbing materials 43 and 44 inside the water storage region 42 always accumulates moisture. The water storage area 42 is thermally connected to the semiconductor chip 41. Moisture supplied onto the semiconductor chip 41 evaporates due to heat generated by the semiconductor chip 41 to become vapor, and cools the semiconductor chip 41 by removing heat from the surroundings by latent heat of evaporation.

The vapor | steam which cooled the semiconductor chip is discharged | emitted from the ventilation duct 45 outside. Since the fan 47 is attached to the ventilation duct 45, discharge | emission of a vapor | steam outside can be accelerated | stimulated and a cooling effect is improved. The moisture supplied to the hygroscopic material or the water absorbing materials 43 and 44 can be obtained from the atmosphere, breathing during conversation, sweat from the palm of the user, water collected from the fuel cell, and the like.
One of the means for supplying water to the internal water storage area is to collect water from the sweat of the palm of the user. This also has the effect of improving the comfort because it makes the contact surface dry. For example, a hygroscopic material can be provided near the microphone to collect moisture from the breath exhaled by the user during the conversation. Since a person's breath contains a large amount of water, the water can be efficiently recovered.

In addition, although not shown, as a refrigerant supply method to the water storage region, water generated by power generation may be used in an electronic device that performs fuel cell power generation. Furthermore, a liquid injection hole may be provided so that the user can supply water directly. In that case, it is better to have a function to inform the user of the amount of water in the internal water storage area by some method. In addition, when water is directly supplied by these methods, a moisture absorbing material or a water absorbing material is not necessarily required. In addition, an embodiment in which a ventilation duct that allows outside air to pass therethrough is provided in the casing of the electronic device or a fan is provided in the ventilation duct is also possible.
Moreover, although the semiconductor chip was mentioned as a heat generating body, it is applicable also to heat generating bodies other than a semiconductor chip. Examples of the heating element other than the semiconductor chip include a hard disk drive (HDD), a hard disk drive motor, a power supply circuit, a battery, a generator, and a fuel cell.

Sectional drawing of the principal part of an electronic device explaining the cooling method of the electronic device of Example 1 which is one Example of this invention. Sectional drawing of the principal part of an electronic device explaining the cooling method of the electronic device of Example 1 which is one Example of this invention. Sectional drawing of the electronic device principal part explaining the cooling method of the electronic device of Example 2 which is one Example of this invention. Sectional drawing of the electronic device principal part explaining the cooling method of the electronic device of Example 3 which is one Example of this invention. Sectional drawing of the form telephone main part explaining the cooling method of the mobile telephone of Example 4 which is one Example of this invention.

Explanation of symbols

1, 21, 31, 41 ... Semiconductor chip 2, 22, 32, 42 ... Water storage area 3, 23, 33, 43, 44 ... Hygroscopic material or water absorbing material 4, 24, 34 ... Transparent Wet sheet 5 ... Metal case 6, 26, 36 ... Moisture absorption 7, 27, 37 ... Steam 25, 35, 45 ... Ventilation duct 28, 38, 48 ... Wick 39, 47 ...・ Fan 40 ... Case 46 ... Opening 49 ... Microphone

Claims (4)

A heating element;
A water storage region having a moisture absorbing material or a water absorbing material,
At least a part of the water storage area is thermally connected to the heating element and cooled by latent heat of vaporization, and at least a part of the hygroscopic material is a moisture permeable sheet made of a film that transmits gas and does not allow liquid to pass through. A method for cooling an electronic device, wherein at least a part of the water storage region that is covered and thermally connected to the heat generating member moves moisture of the water storage region onto the heat generating member by capillary force.   The method for cooling an electronic device according to claim 1, wherein the moisture permeable sheet is partially exposed on a surface of the housing. A housing for storing electronic devices;
A heating element housed in the electronic device;
A water storage region having a moisture absorbing material or a water absorbing material housed in the electronic device,
At least a part of the water storage region is thermally connected to the heating element and cools the heating element by latent heat of vaporization, and at least a part of the moisture absorbing material or the water absorbing material is a film that transmits gas and does not allow liquid to pass through. At least a part of the water storage region that is thermally connected to the heating element moves moisture of the water storage region onto the heating element by capillary force. Electronics. The electronic device according to claim 3, wherein the moisture permeable sheet is partially exposed on a surface of the housing.

Images