WO2015033690A1 - Cooling device - Google Patents

Cooling device Download PDF

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Publication number
WO2015033690A1
WO2015033690A1 PCT/JP2014/069476 JP2014069476W WO2015033690A1 WO 2015033690 A1 WO2015033690 A1 WO 2015033690A1 JP 2014069476 W JP2014069476 W JP 2014069476W WO 2015033690 A1 WO2015033690 A1 WO 2015033690A1
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WIPO (PCT)
Prior art keywords
cooling device
ceramic material
heat
ceramic
cooling
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PCT/JP2014/069476
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French (fr)
Japanese (ja)
Inventor
廣瀬　左京
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株式会社村田製作所
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Publication of WO2015033690A1 publication Critical patent/WO2015033690A1/en

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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
    • H01L23/36—Selection of materials, or shaping, to facilitate cooling or heating, e.g. heatsinks
    • H01L23/373—Cooling facilitated by selection of materials for the device or materials for thermal expansion adaptation, e.g. carbon
    • H01L23/3737—Organic materials with or without a thermoconductive filler
    • C—CHEMISTRY; METALLURGY
    • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K5/00—Heat-transfer, heat-exchange or heat-storage materials, e.g. refrigerants; Materials for the production of heat or cold by chemical reactions other than by combustion
    • C09K5/08—Materials not undergoing a change of physical state when used
    • C09K5/14—Solid materials, e.g. powdery or granular
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F28—HEAT EXCHANGE IN GENERAL
    • F28F—DETAILS OF HEAT-EXCHANGE AND HEAT-TRANSFER APPARATUS, OF GENERAL APPLICATION
    • F28F21/00—Constructions of heat-exchange apparatus characterised by the selection of particular materials
    • F28F21/04—Constructions of heat-exchange apparatus characterised by the selection of particular materials of ceramic; of concrete; of natural stone
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
    • H01L23/36—Selection of materials, or shaping, to facilitate cooling or heating, e.g. heatsinks
    • H01L23/373—Cooling facilitated by selection of materials for the device or materials for thermal expansion adaptation, e.g. carbon
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L23/00—Details of semiconductor or other solid state devices
    • H01L23/34—Arrangements for cooling, heating, ventilating or temperature compensation ; Temperature sensing arrangements
    • H01L23/36—Selection of materials, or shaping, to facilitate cooling or heating, e.g. heatsinks
    • H01L23/373—Cooling facilitated by selection of materials for the device or materials for thermal expansion adaptation, e.g. carbon
    • H01L23/3731—Ceramic materials or glass
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
    • H01L2924/00—Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
    • H01L2924/0001—Technical content checked by a classifier
    • H01L2924/0002—Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Definitions

  • the present invention relates to a cooling device.
  • a cooling device that combines a heat sink and a fan or Peltier element as described above makes the device relatively large and consumes power, making the device smaller and thinner, and lower power consumption (battery life). It is disadvantageous from the point of view. Therefore, development of a cooling device that can be used without a power source and is small is strongly desired.
  • a heat storage material that utilizes latent heat associated with electronic phase transition is known as a heat storage material that does not require electric power (Patent Document 2).
  • latent heat is the total amount of thermal energy required when the phase of a substance changes, and generally refers to the amount of heat absorbed and exothermed with the change of phase.
  • heat storage is to store heat, and cold insulation is to keep the temperature of the object low, and cooling means to lower the temperature of the object.
  • Such a material absorbs heat only in the vicinity of the object in contact with the object to be cooled, and it is clear that the entire cooling device cannot absorb heat and cannot fully utilize the capacity of the cooling device. It was. Therefore, although it can be used in an application in which the space insulated by the heat storage effect is kept for a long time, the temperature rises in a spike shape (steep) when sudden processing is performed like a CPU, for example. It has been found difficult to cool such things efficiently.
  • an object of the present invention is to provide a cooling device that does not require electric power, can be reduced in thickness and size, and has high efficiency and high response.
  • the present inventor is different from a surface in contact with an object to be cooled in a cooling device including a ceramic material that absorbs heat accompanying a crystal structure phase transition or a magnetic phase transition.
  • the inventors have found that the above-mentioned problems can be solved by making the temperatures indicating the latent heat of the ceramic materials at a distance different from each other, and have reached the present invention.
  • a cooling device comprising a ceramic material that absorbs heat, wherein the temperature indicative of the latent heat of the ceramic material at a first distance from the surface in contact with the object to be cooled is the object to be cooled.
  • a cooling device is provided that is different from a temperature indicative of the latent heat of the ceramic material at a second distance from the surface in contact with the surface.
  • a cooling device comprising a ceramic material that absorbs heat associated with a crystal structure phase transition, a magnetic phase transition, etc., the temperature indicating the latent heat of the ceramic material at different distances from the surface in contact with the object to be cooled.
  • FIGS. 1A to 1C are schematic cross-sectional views of a cooling device in which ceramic layers are laminated
  • FIG. 1D is a schematic cross-sectional view of a cooling device having a temperature gradient of phase transition.
  • FIG. 2 shows the results of differential scanning calorimetry in the experimental example.
  • FIG. 3 shows the temperature measurement result of the cooling test in the experimental example.
  • FIG. 4 is a schematic diagram for explaining the result of the cooling test in the experimental example.
  • cooling refers to cooling the cooling object by absorbing the heat generated in the cooling object, and absorbing the heat generated around the cooling object, so that the cooling object is heated. Both prevent it.
  • the temperatures related to latent heat and phase transition such as “temperature indicating latent heat” and “temperature for phase transition” mean the temperature indicating latent heat at the time of temperature rise and the temperature at which the phase transition at the time of temperature rise, unless otherwise specified. To do.
  • the temperature which shows a latent heat, and the temperature which changes a phase mean substantially the same temperature.
  • the cooling device of the present invention comprises a ceramic material that absorbs heat (hereinafter also simply referred to as “ceramic material”).
  • the ceramic material absorbs heat by absorbing latent heat.
  • the latent heat means latent heat accompanying a solid-solid phase transition, such as a crystal structure phase transition or a magnetic phase transition. Using the latent heat accompanying the phase transition of the ceramic material, the heat generated in the object to be cooled or the heat generated around the object to be cooled is absorbed to cool the object to be cooled.
  • the temperature indicating the latent heat is different between the ceramic material at the first distance from the surface in contact with the object to be cooled and the ceramic material at the second distance from the surface in contact with the object to be cooled. .
  • the first distance and the second distance are distances in a direction perpendicular to the surface of the cooling device that contacts the object to be cooled and away from the object to be cooled. It may be a distance.
  • the ceramic material is not particularly limited, and a known ceramic material that undergoes phase transition at a desired temperature can be used. A person skilled in the art can select an appropriate ceramic material according to the desired phase transition temperature, application, and the like.
  • the temperature at which the ceramic material undergoes phase transition is appropriately selected according to the object to be cooled, the purpose of cooling, and the like.
  • the phase transition should be performed at 30 to 100 ° C., preferably 40 to 60 ° C. Is preferred.
  • the ceramic material preferably has a latent heat amount of 5 J / g or more, more preferably 20 J / g or more.
  • the ceramic material preferably has a change in thermal conductivity before and after the phase transition. As a result, it is possible to realize a device that can be cooled more efficiently in terms of heat diffusion, heat dissipation, and heat storage, as well as cooling due to heat absorption caused by latent heat.
  • the ceramic material for electronic phase transition is not particularly limited, for example, ceramic material described in Patent Document 2, specifically, VO 2, LiMn 2 O 4 , LiVS 2, LiVO 2, NaNiO 2, LiRh 2 O 4 , V 2 O 3 , V 4 O 7 , V 6 O 11 , Ti 4 O 7 , SmBaFe 2 O 5 , EuBaFe 2 O 5 , GdBaFe 2 O 5 , TbBaFe 2 O 5 , DyBaFe 2 O 5 , HoBaFe 2 O 5 , YBaFe 2 O 5 , PrBaCo 2 O 5.5 , DyBaCo 2 O 5.54 , HoBaCo 2 O 5.48 , YBaCo 2 O 5.49 , A y VO 2 (wherein A is Li or Na, 0.1 ⁇ y ⁇ 2.0, in preferably 0.5 ⁇ y ⁇ 1.0), V 1-x M x O 2 ( wherein, M represents, W, Ta Mo, Nb
  • the ceramic material used in the cooling device of the present invention is an oxide containing vanadium V and M (where M is at least one selected from W, Ta, Mo and Nb),
  • M is at least one selected from W, Ta, Mo and Nb
  • the molar content of M is about 0 mol parts or more and about 5 mol parts or less. Note that M is not an essential component, and the content molar part of M may be 0.
  • the ceramic material used in the cooling device of the present invention is an oxide containing A (here, A is Li or Na) and vanadium V, where V is 100 mole parts.
  • a mole content of A is from about 50 mole parts to about 100 mole parts.
  • the ceramic material used in the cooling device of the present invention has a composition formula: V 1-x M x O 2 (Wherein, M is W, Ta, Mo or Nb, 0 ⁇ x ⁇ 0.05) Or the composition formula: A y VO 2 (Wherein, A is Li or Na, 0.5 ⁇ y ⁇ 1.0)
  • V 1-x M x O 2 wherein, M is W, Ta, Mo or Nb, 0 ⁇ x ⁇ 0.05
  • a y VO 2 wherein, A is Li or Na, 0.5 ⁇ y ⁇ 1.0
  • the ceramic material used in the cooling device of the present invention has a composition formula: V 1-x W x O 2 (Where 0 ⁇ x ⁇ 0.01) The substance shown by is included as a main component.
  • the main component means a component contained in the ceramic material by 50% by mass or more, particularly 60% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and further preferably 98% by mass. For example, it means 98.0 to 99.8% by mass.
  • Other components include VO x having a different oxygen content from VO 2 .
  • the temperature indicating the latent heat of the ceramic material that is, the temperature at which the ceramic material undergoes phase transition can be adjusted by the amount of the element to be added (dope).
  • a ceramic material has a composition formula: V 1-x W x O 2 When x is 0.005, the phase transition occurs at about 50 ° C., and when x is 0.01, the phase transition occurs at about 40 ° C.
  • the cooling device of the present invention may be a laminate in which two or more ceramic layers each made of a ceramic material that undergoes phase transition at different temperatures are laminated.
  • the ceramic layer may contain other components such as a resin and metal powder described below.
  • the thickness of the ceramic layer is not particularly limited, but is, for example, 0.05 mm to 5 mm, preferably 0.2 mm to 2 mm.
  • the thickness of each ceramic layer may be the same or different.
  • By reducing the thickness of the ceramic layer it is possible to increase the number of ceramic layers in a cooling device of the same thickness, so that the cooling device can have a more gradual phase transition temperature gradient. , Heat diffusion and cooling can be performed more efficiently.
  • the thickness of the ceramic layer is reduced in a cooling device having the same thickness, so that the manufacture is facilitated.
  • the thermal conductivity is also different, so by adjusting the composition and thickness, heat conduction can be improved and worsened to efficiently absorb and It is possible to design according to the object to be cooled and its external environment (such as a heating element nearby) by dissipating heat or efficiently absorbing and insulating heat.
  • the number of laminated ceramic layers is not particularly limited, and is appropriately determined according to the thickness of the cooling device, the thickness of the ceramic layer, and desired characteristics.
  • the number of ceramic layers is increased, it becomes possible to have a more gradual phase transition temperature gradient, and heat diffusion and cooling can be performed more efficiently.
  • the manufacture becomes easier.
  • overheating of the object to be cooled can be suppressed by arranging a thick sample having a low thermal conductivity when heat insulation is desired.
  • the order of stacking the ceramic layers is not particularly limited.
  • the ceramic layers may be stacked in order of increasing phase transition temperature (FIG. 1A), or the ceramic layers having a lower phase transition temperature may undergo phase transition. You may arrange
  • the layer closest to the object to be cooled is a layer that undergoes a phase transition at the temperature to be cooled and controlled
  • a layer farthest from the object to be cooled is a layer that undergoes a phase transition at the lowest temperature.
  • the upper layer absorbs the heat of the cooling target and completes the phase transition relatively early after the temperature of the cooling target starts to rise, and the entire device is cooled with high efficiency and responsiveness. It becomes possible to cool things. Also, in this case, in order to improve the heat diffusion as necessary, the metal foil or carbon sheet having a good thermal conductivity is inserted into or covered with the upper layer portion, the lower layer portion, or the inside, and the heat is more efficiently transferred. Conduction, cooling, and heat dissipation are possible. On the other hand, when heat is generated around the object to be cooled, especially the equipment on the upper layer side, the upper layer is slow to complete the phase transition by arranging a layer having a high temperature showing latent heat in the upper layer.
  • the cooling device by covering the cooling device with a material having a poor thermal conductivity (for example, resin) as necessary, it is possible to further suppress the temperature increase of the cooling target due to the effect of heat insulation. In either situation, if insulation is required, a highly insulating resin or the like may be inserted and covered as necessary.
  • a material having a poor thermal conductivity for example, resin
  • the cooling device of the present invention is such that the temperature at which the ceramic material exhibits latent heat is highest on the surface in contact with the object to be cooled (i.e., the lower part), and gradually decreases with increasing distance from the surface. It can be configured to be the lowest on the surface opposite to the surface in contact with (ie, the upper portion) (FIG. 1 (d)).
  • the upper portion As described above, so that it is possible to cool the cooling target with high efficiency and high response.
  • heat is generated around the object to be cooled, particularly the equipment on the upper side, it is possible to prevent the heat from being transmitted to the lower part by placing it in reverse, so that the object to be cooled is heated. Can be suppressed.
  • the ceramic material may be in the form of particles (powder).
  • the ceramic material By using the ceramic material as particles, the occurrence of cracks can be suppressed even when the phase transition is repeated, and the durability of the cooling device is enhanced.
  • the particle size of the ceramic material particles is not particularly limited.
  • the average particle size is 0.2 to 50 ⁇ m, preferably 0.5 to 50 ⁇ m.
  • Such an average particle diameter can be measured using a laser diffraction / scattering soot particle diameter / particle size distribution measuring apparatus or an electronic scanning microscope.
  • the average particle system is preferably 0.5 ⁇ m or more from the viewpoint of ease of handling, and is preferably 10 ⁇ m or less from the viewpoint of reducing the porosity between particles.
  • the cooling device of the present invention may include metal particles (for example, powder). Since the metal particles have higher thermal conductivity than the ceramic material, the heat of the object to be cooled can be efficiently transmitted to a wide area of the cooling device by using the metal particles.
  • a powder obtained by coating a ceramic particle with a metal using a chemical or physical method may be used.
  • the metal particles need only be in contact with the ceramic material.
  • the metal particles may be dispersed in the cooling device and may be present uniformly or non-uniformly.
  • the cooling device is composed of ceramic layers, it may be present in all ceramic layers, or may be present in some ceramic layers.
  • the ceramic material forming the layer is a lump, it can be dispersed therein, and when the ceramic material forming the layer is a particle, it can be present as a mixture of particles of ceramic material and metal particles.
  • the metal particles are not particularly limited as long as they have higher thermal conductivity than the ceramic material, and examples thereof include particles made of tin, nickel, copper, silver, aluminum, and the like. These metal particles may be used alone or in combination of two or more metal particles. Preferred metal particles are tin, silver, or copper particles.
  • the particle size of the metal particles (powder) is not particularly limited.
  • the average particle size is 0.5 to 100 ⁇ m, preferably 1 to 50 ⁇ m.
  • Such an average particle diameter can be measured using a laser diffraction / scattering soot particle diameter / particle size distribution measuring apparatus or a scanning electron microscope.
  • the average particle system is preferably 1 ⁇ m or more from the viewpoint of ease of handling, and is preferably 50 ⁇ m or less from the viewpoint of reducing the porosity between particles.
  • the mixing ratio of the ceramic material and the metal particles is not particularly limited.
  • the volume ratio is 8: 2 to 2: 8, preferably 6: 4 to 3: 7.
  • the volume ratio between the ceramic material and the metal particles can be obtained by measuring the respective weights and calculating the volume from the theoretical density.
  • the thermal conductivity inside the cooling device can be improved, and the cooling efficiency can be increased.
  • the strength of the cooling device after molding can be increased.
  • the amount of heat that can be absorbed can be increased by increasing the proportion of the ceramic material.
  • the cooling device of the present invention may contain a resin.
  • a resin By including a resin in the cooling device, flexibility can be given to the cooling device, and the strength of the cooling device can be increased.
  • the resin since the resin has a high resistance, the resistance of the cooling device can be increased by compounding, and there is an advantage that it is possible to suppress a short circuit or interference of radio waves.
  • the resin is not particularly limited, and examples thereof include acrylic resin, epoxy, polyester, silicon, polyurethane, polyethylene, polypropylene, polystyrene, nylon, polycarbonate, and polybutylene terephthalate.
  • the content of the resin is not particularly limited, but is preferably equal to or more than an amount capable of filling a gap between particles (including metal particles and ceramic material particles, if present). 10 to 60 parts by volume is preferable with respect to 100 parts by volume in total of the metal particles.
  • the cooling device of the present invention may have a heat conducting portion made of a material having a higher thermal conductivity than the ceramic material (hereinafter also referred to as “high heat conducting material”).
  • the heat conducting unit has a function of efficiently transferring heat generated in the object to be cooled to a wide area of the cooling device.
  • the high thermal conductivity material is not particularly limited as long as it has a higher thermal conductivity than the ceramic material, and examples thereof include metal materials and resins, preferably metal materials and composite materials thereof, graphite, and graphene sheets. Used.
  • the high thermal conductivity material is not particularly limited as long as it has a higher thermal conductivity than the ceramic material, but includes metal materials, resins, nitrides such as AlN, and oxides such as Al 2 O 3 , Metal materials and composite materials thereof, graphite, and graphene are preferable.
  • the metal material is not particularly limited, and examples thereof include tin, nickel, copper, bismuth, silver, iron, aluminum, and alloys containing them. This metal material may be the same metal as the metal particles or may be different. These metal materials may be used alone or in combination of two or more.
  • the shape and arrangement of the high heat conduction part are not particularly limited as long as the heat generated in the object to be cooled can be transmitted to a wide area of the cooling device.
  • the heat conducting part has a contact part with the object to be cooled, and is arranged so as to contact the ceramic material at a position away from the contact part.
  • the heat conducting part is disposed so as to surround the periphery of the cooling device, that is, can be disposed so as to package the ceramic material and the metal particles.
  • the cooling device of the present invention may have elasticity.
  • the cooling device can be fixed more easily and stably by being sandwiched between other members.
  • the method for imparting elasticity to the cooling device of the present invention is not particularly limited, and examples thereof include a method of containing a resin.
  • the shape of the cooling device of the present invention is not particularly limited, and may be, for example, a block shape or a sheet shape. If necessary, the surface of the device may be roughened to increase the surface area.
  • the cooling device By making the cooling device into a sheet shape, the surface area increases, so it becomes easier to release the absorbed heat to the outside. Moreover, when it is set as a sheet form, the softness
  • the manufacturing method of the cooling device of the present invention is not particularly limited.
  • the ceramic material constitutes the ceramic layer
  • the ceramic layer is separately formed using ceramic materials having different temperatures indicating phase transition. And it can produce by crimping
  • pastes containing ceramic materials having different temperatures exhibiting phase transition can be laminated and compression molded to obtain a laminate.
  • the laminate may be sintered by heat treatment after compression molding. In this case, it is possible to manufacture a cooling device in which the transition temperature is continuously changed by mutual diffusion of W or the like added for controlling the transition temperature during firing.
  • the cooling device of the present invention can be molded into a desired shape and can also be given flexibility, it can function as a cooling device and can also be used as another member such as a substrate, a case, or a cushioning material. Can be used.
  • V 2 O 3 Vanadium trioxide
  • V 2 O 5 vanadium pentoxide
  • WO 3 tungsten oxide
  • V: W: O It weighed so that it might become 0.995: 0.005: 2 (molar ratio), and it dry-mixed. Thereafter, heat treatment was performed at 1000 ° C. for 4 hours in a nitrogen / hydrogen / water atmosphere to prepare a powder of V 0.995 W 0.005 O 2 (0.5 at% W-doped VO 2 ) as a ceramic material.
  • pure water, partially stabilized zirconium (PSZ) balls, a dispersant (manufactured by San Nopco: SN5468) and the ceramic material powder obtained above are added to a polypot and pulverized and mixed for 24 hours. Thereafter, an acrylic binder, a plasticizer and an antifoaming agent were added and mixed again for 2 hours to obtain a sheet forming slurry.
  • PSZ partially stabilized zirconium
  • a sheet forming slurry was formed into a sheet to produce a green sheet, then cut into strips, and a ceramic single plate was produced by a crimping process.
  • This ceramic single plate is subjected to a degreasing treatment in the atmosphere at 300 ° C., and then sintered by heat treatment at 1000 ° C. for 4 hours in a nitrogen / hydrogen / water atmosphere to obtain a size of 20 mm ⁇ 20 mm ⁇ 5 mm.
  • a ceramic single plate cooling device was fabricated.
  • Cooling test A PTC (positive temperature coefficient) heater with an ultimate temperature of about 60 ° C. was used as a heating element, and heat conduction grease was applied to the surface of the PTC heater, and an ultrafine K thermocouple was applied thereon, and the above was produced from above.
  • the sintered ceramic single plate cooling device was pressed and fixed. Further, an ultrafine K thermocouple was attached to the upper surface of the cooling device (the surface opposite to the surface in contact with the PTC heater).
  • heat conduction grease was applied to the surface of another PTC heater for reference, and an ultrafine K thermocouple was attached (no cooling device).
  • the surface (contact surface) temperature of the PTC heater is slightly lowered by using the sintered ceramic single plate cooling device as compared with the case where this cooling device is not used.
  • the temperature of the upper surface of the cooling device has a large temperature difference from the contact surface and does not sufficiently contribute to heat absorption.
  • the heat of the PTC heater 4 is transmitted to the lower part of the sintered ceramic single plate 2 that is in contact with the PTC heater 4 (the x part in FIG. 4). It is thought that this is because the amount of heat transferred from the ceramic material of the x portion to the upper portion of the sintered ceramic single plate (y portion in FIG. 4) is reduced while absorbing the heat required for.
  • the cooling effect is seen for a while after the PTC heater is energized, but after 400 seconds, the cooling effect is hardly seen even though the temperature of the upper surface of the cooling device is low, and the merit of using the cooling device is small. It was confirmed.
  • the resulting ceramic material powder, pure water, partially stabilized zirconium (PSZ) balls, and a dispersant are added to a polypot and mixed for 24 hours, followed by acrylic binder, plasticizer and antifoam.
  • the agent was added and mixed again for 2 hours to obtain sheet forming slurries A to C corresponding to the ceramic materials A to C.
  • each of the sheet forming slurries A to C is formed into a sheet to produce green sheets A to C. Thereafter, each of the green sheets A to C is cut into strips, and about 1
  • the green sheets A to C were laminated to 6 mm, and the laminated green sheets A to C were pressure-bonded and cut in the order of A to C to prepare a laminate having a size of 20 mm ⁇ 20 mm ⁇ 5 mm.
  • Comparative Example 1 A laminate of Comparative Example 1 having a size of 20 mm ⁇ 20 mm ⁇ 5 mm was obtained in the same manner as Example 1 except that only the green sheet A was laminated.
  • Cooling test As a heating element, a PTC heater having an ultimate temperature of about 60 ° C. was used, heat conduction grease was applied to the heater surface, and an ultrafine K thermocouple was attached thereto. One cooling device was pressed and fixed. In the cooling device of Example 1, the green sheet C side was the cooling device side. For reference, an extra fine K thermocouple was attached to the surface of the heater without a cooling device.
  • the rated current was applied to the PTC heater using a DC power supply, and the temperature of the PTC heater surface after 200 seconds and 600 seconds was measured to evaluate the cooling effect.
  • the results are shown in Table 2.
  • the cooling device of Comparative Example 1 using only one kind of ceramic material shows a cooling effect at 200 seconds after energizing the PTC heater, but after 600 seconds, the cooling effect is seen. I can't. As described in the experimental example, this is considered to be because heat conduction is suppressed while the ceramic material is absorbing heat, and the vicinity of the upper surface of the cooling device cannot sufficiently contribute to heat absorption.
  • the cooling device of Example 1 using three kinds of ceramic materials has a larger cooling effect after 200 seconds than the cooling device of Comparative Example 1, and also exhibits a sufficient cooling effect after 600 seconds. It was confirmed.
  • the cooling device of the present invention can be used, for example, as a cooling device for a small communication terminal in which a thermal countermeasure problem has become prominent.

Abstract

The present invention provides a cooling device that has high efficiency and high responsiveness, can have increased compactness and increased thinness, and does not require electrical power. The cooling device, which comprises a ceramic material having latent heat, is characterized by a temperature indicating the latent heat of the ceramic material at a first distance from a surface contacting a cooling subject being different from a temperature indicating the latent heat of the ceramic material at a second distance from the surface contacting the cooling subject.

Description

冷却デバイスCooling device
　本発明は、冷却デバイスに関する。 The present invention relates to a cooling device.
　近年、小型通信機器の進歩により薄くて軽いスマートフォンやタブレット型端末が広く普及し始めている。このような機器においてもパーソナルコンピューターと同様に高性能化が進められ、それに伴いＣＰＵなどの発熱に関する問題が顕著化しており、機器の内部温度を、より高度に制御することが求められている。このような課題に対しては、従来からヒートシンクとファンまたはペルチェ素子を組み合わせた冷却装置が知られている（特許文献１を参照）。 In recent years, thin and light smartphones and tablet terminals have begun to spread widely due to the progress of small communication devices. In such devices as well as personal computers, higher performance has been promoted, and accordingly, problems related to heat generation of the CPU and the like have become more prominent, and it is required to control the internal temperature of the devices to a higher degree. Conventionally, a cooling device combining a heat sink and a fan or a Peltier element is known for such problems (see Patent Document 1).
特開２０１０－２２３４９７号公報JP 2010-223497 A 特開２０１０－１６３５１０号公報JP 2010-163510 A
　上記のようなヒートシンクとファンまたはペルチェ素子を組み合わせた冷却装置は、機器が比較的大きくなり、また、電力を消費するので、機器の小型化・薄型化、および低消費電力（バッテリーの持ち時間）の観点から不利である。したがって、無電源で使用可能で、かつ小型な冷却デバイスの開発が強く望まれている。 A cooling device that combines a heat sink and a fan or Peltier element as described above makes the device relatively large and consumes power, making the device smaller and thinner, and lower power consumption (battery life). It is disadvantageous from the point of view. Therefore, development of a cooling device that can be used without a power source and is small is strongly desired.
　一方、電力を必要としない蓄熱材として電子相転移に伴う潜熱を利用する蓄熱材が知られている（特許文献２）。ここで潜熱とは、物質の相が変化するときに必要とされる熱エネルギーの総量であり、一般的に相の変化に伴う吸発熱量の事をいう。蓄熱とはその名の通り熱を蓄えることであり、保冷とは対象物の温度を低い状態に保つことであり、冷却とは対象物の温度を下げることを意味する。本発明者の検討の結果、このような材料を用いることにより、蓄熱、保冷効果に加え、冷却したい対象物（例えば、ＣＰＵ）を冷却する効果を一応得ることができることが確認されたが、このような材料は、冷却対象物に接している近傍の部分だけで熱を吸収し、冷却デバイス全体で熱を吸収することができず冷却デバイスの能力を最大限利用できていないことが明らかになった。したがって、蓄熱効果により断熱された空間を長時間にわたって保冷する用途では使用することができるが、例えば、ＣＰＵのように、突発的な処理を行った際にスパイク状（急峻）に温度が上昇するようなものの冷却を効率よく行うことは難しいことが見出された。 On the other hand, a heat storage material that utilizes latent heat associated with electronic phase transition is known as a heat storage material that does not require electric power (Patent Document 2). Here, latent heat is the total amount of thermal energy required when the phase of a substance changes, and generally refers to the amount of heat absorbed and exothermed with the change of phase. As the name suggests, heat storage is to store heat, and cold insulation is to keep the temperature of the object low, and cooling means to lower the temperature of the object. As a result of the inventor's investigation, it was confirmed that by using such a material, in addition to the heat storage and cooling effect, the effect of cooling the object (for example, CPU) to be cooled can be obtained. Such a material absorbs heat only in the vicinity of the object in contact with the object to be cooled, and it is clear that the entire cooling device cannot absorb heat and cannot fully utilize the capacity of the cooling device. It was. Therefore, although it can be used in an application in which the space insulated by the heat storage effect is kept for a long time, the temperature rises in a spike shape (steep) when sudden processing is performed like a CPU, for example. It has been found difficult to cool such things efficiently.
　したがって、本発明の目的は、電力を必要とせず、薄型化・小型化が可能であり、高効率かつ高応答の冷却デバイスを提供することにある。 Therefore, an object of the present invention is to provide a cooling device that does not require electric power, can be reduced in thickness and size, and has high efficiency and high response.
　本発明者は、上記問題を解消すべく鋭意検討した結果、結晶構造相転移や磁気相転移等に伴う熱を吸収するセラミックス材料を含んで成る冷却デバイスにおいて、冷却対象物と接触する面から異なる距離にあるセラミックス材料の潜熱を示す温度が互いに異なるようにすることにより、上記の問題を解決できることを見出し、本発明に至った。 As a result of intensive studies to solve the above problems, the present inventor is different from a surface in contact with an object to be cooled in a cooling device including a ceramic material that absorbs heat accompanying a crystal structure phase transition or a magnetic phase transition. The inventors have found that the above-mentioned problems can be solved by making the temperatures indicating the latent heat of the ceramic materials at a distance different from each other, and have reached the present invention.
　本発明の要旨によれば、熱を吸収するセラミックス材料を含んで成る冷却デバイスであって、冷却対象物と接触する面から第１の距離にあるセラミックス材料の潜熱を示す温度が、冷却対象物と接触する面から第２の距離にあるセラミックス材料の潜熱を示す温度と異なることを特徴とする冷却デバイスが提供される。 According to the gist of the present invention, a cooling device comprising a ceramic material that absorbs heat, wherein the temperature indicative of the latent heat of the ceramic material at a first distance from the surface in contact with the object to be cooled is the object to be cooled. A cooling device is provided that is different from a temperature indicative of the latent heat of the ceramic material at a second distance from the surface in contact with the surface.
　本発明によれば、結晶構造相転移や磁気相転移等に伴う熱を吸収するセラミックス材料を含んで成る冷却デバイスにおいて、冷却対象物と接触する面から異なる距離にあるセラミックス材料の潜熱を示す温度が互いに異なるようにすることにより、薄型化・小型化が可能であり、電力を用いることなく、効率よく冷却対象物を冷却することができ、かつ、冷却対象物の急激な温度の上昇に対応できる冷却デバイスが提供される。 According to the present invention, in a cooling device comprising a ceramic material that absorbs heat associated with a crystal structure phase transition, a magnetic phase transition, etc., the temperature indicating the latent heat of the ceramic material at different distances from the surface in contact with the object to be cooled. By making them different from each other, it is possible to reduce the thickness and size, to cool the object to be cooled efficiently without using electric power, and to respond to the sudden rise in temperature of the object to be cooled. Possible cooling devices are provided.
図１（ａ）～（ｃ）は、セラミックス層を積層した冷却デバイスの概略断面図を示し、図１（ｄ）は、相転移する温度の勾配を有する冷却デバイスの概略断面図である。FIGS. 1A to 1C are schematic cross-sectional views of a cooling device in which ceramic layers are laminated, and FIG. 1D is a schematic cross-sectional view of a cooling device having a temperature gradient of phase transition. 図２は、実験例における示差走査熱量測定の結果を示す。FIG. 2 shows the results of differential scanning calorimetry in the experimental example. 図３は、実験例における冷却試験の温度測定結果を示す。FIG. 3 shows the temperature measurement result of the cooling test in the experimental example. 図４は、実験例における冷却試験の結果を説明するための模式図である。FIG. 4 is a schematic diagram for explaining the result of the cooling test in the experimental example.
　本明細書において、「冷却」とは、冷却対象物で生じた熱を吸収して冷却対象物を冷却すること、および冷却対象物の周囲で生じた熱を吸収し、冷却対象物が加熱されることを防止することの両方を意味する。 In this specification, “cooling” refers to cooling the cooling object by absorbing the heat generated in the cooling object, and absorbing the heat generated around the cooling object, so that the cooling object is heated. Both prevent it.
　本明細書において、「潜熱を示す温度」および「相転移する温度」といった潜熱および相転移に関する温度は、特記しない限り、それぞれ、昇温時に潜熱を示す温度および昇温時に相転移する温度を意味する。なお、潜熱を示す温度および相転移する温度は、実質的に同じ温度を意味する。 In the present specification, the temperatures related to latent heat and phase transition such as “temperature indicating latent heat” and “temperature for phase transition” mean the temperature indicating latent heat at the time of temperature rise and the temperature at which the phase transition at the time of temperature rise, unless otherwise specified. To do. In addition, the temperature which shows a latent heat, and the temperature which changes a phase mean substantially the same temperature.
　本発明の冷却デバイスは、熱を吸収するセラミックス材料（以下、単に「セラミックス材料」ともいう）を含んで成る。このセラミックス材料の熱の吸収は、潜熱を吸収することにより為される。前記潜熱は、固体－固体の相転移、例えば結晶構造相転移や磁気相転移等に伴う潜熱を意味する。このセラミックス材料の相転移に伴う潜熱を利用し、冷却対象物で生じる熱または冷却対象物の周囲で生じる熱を吸収し、冷却対象物を冷却する。 The cooling device of the present invention comprises a ceramic material that absorbs heat (hereinafter also simply referred to as “ceramic material”). The ceramic material absorbs heat by absorbing latent heat. The latent heat means latent heat accompanying a solid-solid phase transition, such as a crystal structure phase transition or a magnetic phase transition. Using the latent heat accompanying the phase transition of the ceramic material, the heat generated in the object to be cooled or the heat generated around the object to be cooled is absorbed to cool the object to be cooled.
　本発明の冷却デバイスにおいて、冷却対象物と接触する面から第１の距離にあるセラミックス材料と、冷却対象物と接触する面から第２の距離にあるセラミックス材料とは、潜熱を示す温度が異なる。 In the cooling device of the present invention, the temperature indicating the latent heat is different between the ceramic material at the first distance from the surface in contact with the object to be cooled and the ceramic material at the second distance from the surface in contact with the object to be cooled. .
　上記第１の距離および第２の距離とは、冷却デバイスの冷却対象物と接触する面に対して垂直に、冷却対象物から離れる方向への距離を意味し、互いに異なってさえいれば、いかなる距離であってもよい。 The first distance and the second distance are distances in a direction perpendicular to the surface of the cooling device that contacts the object to be cooled and away from the object to be cooled. It may be a distance.
　上記セラミックス材料は、特に限定されず、所望の温度で相転移する公知のセラミックス材料を用いることができる。当業者であれば、所望の相転移温度、用途等に応じて、適当なセラミックス材料を選択することができる。 The ceramic material is not particularly limited, and a known ceramic material that undergoes phase transition at a desired temperature can be used. A person skilled in the art can select an appropriate ceramic material according to the desired phase transition temperature, application, and the like.
　上記セラミックス材料が相転移する温度は、冷却対象物、冷却目的などに応じて適宜選択され、例えば冷却対象物がＣＰＵである場合、３０～１００℃、好ましくは４０～６０℃で相転移することが好ましい。 The temperature at which the ceramic material undergoes phase transition is appropriately selected according to the object to be cooled, the purpose of cooling, and the like. For example, when the object to be cooled is a CPU, the phase transition should be performed at 30 to 100 ° C., preferably 40 to 60 ° C. Is preferred.
　上記セラミックス材料は、好ましくは５Ｊ／ｇ以上、より好ましくは２０Ｊ／ｇ以上の潜熱量を有する。大きな潜熱量を有することにより、より小さな体積で大きな冷却効果を発揮できるので、小型化の点で有利である。 The ceramic material preferably has a latent heat amount of 5 J / g or more, more preferably 20 J / g or more. By having a large amount of latent heat, a large cooling effect can be exhibited with a smaller volume, which is advantageous in terms of miniaturization.
　上記セラミックス材料は好ましくは相転移前後で熱伝導率が変化することが好ましい。これにより潜熱に起因する吸熱により冷却だけでなく、熱拡散・放熱・蓄熱の観点でより効率よく冷却できるデバイスを実現することが可能となる。 The ceramic material preferably has a change in thermal conductivity before and after the phase transition. As a result, it is possible to realize a device that can be cooled more efficiently in terms of heat diffusion, heat dissipation, and heat storage, as well as cooling due to heat absorption caused by latent heat.
　電子相転移するセラミックス材料としては、特に限定されないが、例えば特許文献２に記載のセラミックス材料、具体的には、ＶＯ２、ＬｉＭｎ２Ｏ４、ＬｉＶＳ２、ＬｉＶＯ２、ＮａＮｉＯ２、ＬｉＲｈ２Ｏ４、Ｖ２Ｏ３、Ｖ４Ｏ７、Ｖ６Ｏ１１、Ｔｉ４Ｏ７、ＳｍＢａＦｅ２Ｏ５、ＥｕＢａＦｅ２Ｏ５、ＧｄＢａＦｅ２Ｏ５、ＴｂＢａＦｅ２Ｏ５、ＤｙＢａＦｅ２Ｏ５、ＨｏＢａＦｅ２Ｏ５、ＹＢａＦｅ２Ｏ５、ＰｒＢａＣｏ２Ｏ５．５、ＤｙＢａＣｏ２Ｏ５．５４、ＨｏＢａＣｏ２Ｏ５．４８、ＹＢａＣｏ２Ｏ５．４９、ＡｙＶＯ２（式中、ＡはＬｉまたはＮａであり、０．１≦ｙ≦２．０、好ましくは０．５≦ｙ≦１．０）、Ｖ１－ｘＭｘＯ２（式中、Ｍは、Ｗ、Ｔａ、Ｍｏ、Ｎｂ、ＲｕまたはＲｅであり、０≦ｘ≦０．２、好ましくは０≦ｘ≦０．０５）等が挙げられる。 The ceramic material for electronic phase transition, is not particularly limited, for example, ceramic material described in Patent Document 2, specifically, VO 2, LiMn 2 O 4 , LiVS 2, LiVO 2, NaNiO 2, LiRh 2 O 4 , V 2 O 3 , V 4 O 7 , V 6 O 11 , Ti 4 O 7 , SmBaFe 2 O 5 , EuBaFe 2 O 5 , GdBaFe 2 O 5 , TbBaFe 2 O 5 , DyBaFe 2 O 5 , HoBaFe 2 O 5 , YBaFe 2 O 5 , PrBaCo 2 O 5.5 , DyBaCo 2 O 5.54 , HoBaCo 2 O 5.48 , YBaCo 2 O 5.49 , A y VO 2 (wherein A is Li or Na, 0.1 ≦ y ≦ 2.0, in preferably 0.5 ≦ y ≦ 1.0), V 1-x M x O 2 ( wherein, M represents, W, Ta Mo, Nb, a Ru or Re, 0 ≦ x ≦ 0.2, preferably include 0 ≦ x ≦ 0.05) or the like.
　好ましい態様において、本発明の冷却デバイスに用いられるセラミックス材料は、バナジウムＶおよびＭ（ここに、Ｍは、Ｗ、Ｔａ、ＭｏおよびＮｂから選ばれる少なくとも一種である）を含む酸化物であって、ＶとＭの合計を１００モル部としたときのＭの含有モル部が約０モル部以上約５モル部以下である。なお、Ｍは必須成分ではなく、Ｍの含有モル部は０であってもよい。 In a preferred embodiment, the ceramic material used in the cooling device of the present invention is an oxide containing vanadium V and M (where M is at least one selected from W, Ta, Mo and Nb), When the total amount of V and M is 100 mol parts, the molar content of M is about 0 mol parts or more and about 5 mol parts or less. Note that M is not an essential component, and the content molar part of M may be 0.
　別の好ましい態様において、本発明の冷却デバイスに用いられるセラミックス材料は、Ａ（ここに、ＡはＬｉまたはＮａである）およびバナジウムＶを含む酸化物であって、Ｖを１００モル部としたときのＡの含有モル部が約５０モル部以上約１００モル部以下である。 In another preferred embodiment, the ceramic material used in the cooling device of the present invention is an oxide containing A (here, A is Li or Na) and vanadium V, where V is 100 mole parts. The A mole content of A is from about 50 mole parts to about 100 mole parts.
　また、別の好ましい態様において、本発明の冷却デバイスに用いられるセラミックス材料は、組成式：
　　　Ｖ１－ｘＭｘＯ２
（式中、Ｍは、Ｗ、Ｔａ、ＭｏまたはＮｂであり、０≦ｘ≦０．０５）
または、組成式：
　　　　ＡｙＶＯ２
　（式中、ＡはＬｉまたはＮａであり、０．５≦ｙ≦１．０）
で表される１種またはそれ以上の物質を主成分として含む。 In another preferred embodiment, the ceramic material used in the cooling device of the present invention has a composition formula:
V 1-x M x O 2
(Wherein, M is W, Ta, Mo or Nb, 0 ≦ x ≦ 0.05)
Or the composition formula:
A y VO 2
(Wherein, A is Li or Na, 0.5 ≦ y ≦ 1.0)
As a main component, one or more substances represented by the formula:
　より好ましい態様において、本発明の冷却デバイスに用いられるセラミックス材料は、組成式：
　　　Ｖ１－ｘＷｘＯ２
（式中、０≦ｘ≦０．０１）
で示される物質を主成分として含む。 In a more preferred embodiment, the ceramic material used in the cooling device of the present invention has a composition formula:
V 1-x W x O 2
(Where 0 ≦ x ≦ 0.01)
The substance shown by is included as a main component.
　ここで、主成分とは、セラミックス材料中に５０質量％以上含まれる成分を意味し、特に６０質量％以上、好ましくは８０質量％以上、より好ましくは９０質量％以上、さらに好ましくは９８質量％以上、例えば９８．０～９９．８質量％含むことを意味する。その他の成分としては、ＶＯ２と酸素量の異なるＶＯｘが挙げられる。 Here, the main component means a component contained in the ceramic material by 50% by mass or more, particularly 60% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, and further preferably 98% by mass. For example, it means 98.0 to 99.8% by mass. Other components include VO x having a different oxygen content from VO 2 .
　セラミックス材料の潜熱を示す温度、即ち、セラミックス材料が相転移する温度は、添加（ドープ）する元素の添加量により調節することができる。 The temperature indicating the latent heat of the ceramic material, that is, the temperature at which the ceramic material undergoes phase transition can be adjusted by the amount of the element to be added (dope).
　例えば、セラミックス材料が、組成式：
　　　Ｖ１－ｘＷｘＯ２
で示される場合、ｘを０．００５とすると、相転移は約５０℃で起こり、ｘを０．０１とすると、相転移は約４０℃で起こる。 For example, a ceramic material has a composition formula:
V 1-x W x O 2
When x is 0.005, the phase transition occurs at about 50 ° C., and when x is 0.01, the phase transition occurs at about 40 ° C.
　一の態様において、本発明の冷却デバイスは、それぞれ異なる温度で相転移するセラミックス材料から構成された２つまたはそれ以上のセラミックス層が積層された積層体であり得る。かかるセラミックス層は、上記セラミックス材料に加え、他の成分、例えば下記する樹脂、金属粉末などを含んでいてもよい。 In one embodiment, the cooling device of the present invention may be a laminate in which two or more ceramic layers each made of a ceramic material that undergoes phase transition at different temperatures are laminated. In addition to the ceramic material, the ceramic layer may contain other components such as a resin and metal powder described below.
　上記セラミックス層の厚みは、特に限定されるものではないが、例えば、０．０５ｍｍ～５ｍｍ、好ましくは０．２ｍｍ～２ｍｍである。各セラミックス層の厚みは、同じであってもよく、異なっていてもよい。セラミックス層の厚みを薄くすることにより、同じ厚みの冷却デバイスにおいて、セラミックス層の数を多くすることができるので、冷却デバイスに、より段階的な相転移温度の勾配を持たせることが可能になり、熱の拡散・冷却をより効率よく行うことができる。他方、セラミックス層の厚みを厚くすることにより、同じ厚みの冷却デバイスにおいて、セラミックス層の数が少なくなるので製造が容易になる。 The thickness of the ceramic layer is not particularly limited, but is, for example, 0.05 mm to 5 mm, preferably 0.2 mm to 2 mm. The thickness of each ceramic layer may be the same or different. By reducing the thickness of the ceramic layer, it is possible to increase the number of ceramic layers in a cooling device of the same thickness, so that the cooling device can have a more gradual phase transition temperature gradient. , Heat diffusion and cooling can be performed more efficiently. On the other hand, by increasing the thickness of the ceramic layer, the number of ceramic layers is reduced in a cooling device having the same thickness, so that the manufacture is facilitated.
　また、Ｗ添加量により潜熱を示す温度が異なることに加え、熱伝導率も異なることから、組成や厚みを調整することで、熱伝導を良くしたり悪くしたりして効率よく熱を吸収・放熱させたり、効率よく熱を吸収し、断熱することで冷却対象物とその外部環境（近くに発熱体がある等）に応じた設計が可能となる。 Also, in addition to the temperature showing latent heat depending on the amount of W added, the thermal conductivity is also different, so by adjusting the composition and thickness, heat conduction can be improved and worsened to efficiently absorb and It is possible to design according to the object to be cooled and its external environment (such as a heating element nearby) by dissipating heat or efficiently absorbing and insulating heat.
　上記セラミックス層の積層数は、特に限定されず、冷却デバイスの厚みおよびセラミックス層の厚み、所望の特性に応じて、適宜決定される。セラミックス層の数を多くすると、より段階的な相転移温度の勾配を持たせることが可能になり、熱の拡散・冷却をより効率よく行うことができる。他方、セラミックス層の数を少なくすると、製造が容易になる。また厚みにより熱の伝わり方を変えることができるため、断熱したい時には熱伝導の低い組成の試料を厚く配置することで冷却対象物の過熱を抑制することもできる。 The number of laminated ceramic layers is not particularly limited, and is appropriately determined according to the thickness of the cooling device, the thickness of the ceramic layer, and desired characteristics. When the number of ceramic layers is increased, it becomes possible to have a more gradual phase transition temperature gradient, and heat diffusion and cooling can be performed more efficiently. On the other hand, if the number of ceramic layers is reduced, the manufacture becomes easier. In addition, since the way in which heat is transmitted can be changed depending on the thickness, overheating of the object to be cooled can be suppressed by arranging a thick sample having a low thermal conductivity when heat insulation is desired.
　上記セラミックス層の積層順は、特に限定されず、例えば、相転移する温度の高い順に積層してもよく（図１（ａ））、あるいは、相転移する温度が低いセラミックス層を、相転移する温度が高いセラミックス層で挟むように（図１（ｂ））、またはその逆に（図１（ｃ））配置してもよい。 The order of stacking the ceramic layers is not particularly limited. For example, the ceramic layers may be stacked in order of increasing phase transition temperature (FIG. 1A), or the ceramic layers having a lower phase transition temperature may undergo phase transition. You may arrange | position so that it may pinch | interpose with a ceramic layer with high temperature (FIG.1 (b)), or the contrary (FIG.1 (c)).
　好ましい態様において、冷却対象物の発熱が対象物の加熱の原因である場合は、冷却対象物に最も近い層（以下、最下層ともいう）を、冷却・制御したい温度で相転移する層とし、冷却対象物から離れるに従って、より低い温度で相転移する層とし、冷却対象物から最も遠い層（以下、最上層ともいう）が、最も低い温度で相転移する層とすることが好ましい。このように積層することにより、冷却対象物の温度が上昇し始めてから比較的早期に、上層が冷却対象物の熱を吸収して相転移を完了させ、デバイス全体で高効率で応答よく冷却対象物を冷却することが可能になる。またこの場合、必要に応じて熱の拡散をより良くするため、熱伝導率の良い金属箔やカーボンシート等を上層部や下層部、また内部に挿入したり、覆うことでより効率よく熱の伝導・冷却・放熱させることが可能となる。一方、冷却対象物の周囲、特に上層側にある機器で熱が発生する場合、逆に潜熱を示す温度が高い層を上層に配置することにより、上層は相転移が完了するのが遅く、下層に熱が伝わるのを抑制することができるので、外部の熱から冷却対象物を保護することが可能になる。またこの場合、必要に応じて熱伝導率の悪い材料（例えば樹脂）などで冷却デバイスを覆うことで、断熱の効果により冷却対象物の温度上昇をより抑えることが可能となる。またどちらの状況においても絶縁が必要な場合は必要に応じて絶縁性の高い樹脂等を挿入、覆ってもよい。 In a preferred embodiment, when the heat generation of the object to be cooled is the cause of the heating of the object, the layer closest to the object to be cooled (hereinafter also referred to as the lowermost layer) is a layer that undergoes a phase transition at the temperature to be cooled and controlled, It is preferable that a layer undergoes a phase transition at a lower temperature as it is separated from the object to be cooled, and a layer farthest from the object to be cooled (hereinafter also referred to as the uppermost layer) is a layer that undergoes a phase transition at the lowest temperature. By laminating in this way, the upper layer absorbs the heat of the cooling target and completes the phase transition relatively early after the temperature of the cooling target starts to rise, and the entire device is cooled with high efficiency and responsiveness. It becomes possible to cool things. Also, in this case, in order to improve the heat diffusion as necessary, the metal foil or carbon sheet having a good thermal conductivity is inserted into or covered with the upper layer portion, the lower layer portion, or the inside, and the heat is more efficiently transferred. Conduction, cooling, and heat dissipation are possible. On the other hand, when heat is generated around the object to be cooled, especially the equipment on the upper layer side, the upper layer is slow to complete the phase transition by arranging a layer having a high temperature showing latent heat in the upper layer. Therefore, it is possible to protect the object to be cooled from external heat. Further, in this case, by covering the cooling device with a material having a poor thermal conductivity (for example, resin) as necessary, it is possible to further suppress the temperature increase of the cooling target due to the effect of heat insulation. In either situation, if insulation is required, a highly insulating resin or the like may be inserted and covered as necessary.
　別の態様において、本発明の冷却デバイスは、セラミックス材料が潜熱を示す温度が、冷却対象物と接触する面（即ち、下部）において最も高く、前記面から離れるに従って徐々に低くなり、冷却対象物と接触する面と反対の面（即ち、上部）で最も低くなるように構成することができる（図１（ｄ））。このような構成とすることにより、上記と同様に、熱を上部に効率よく伝えることが可能になるので、高効率で応答よく冷却対象物を冷却することが可能になる。一方、冷却対象物の周囲、特に上部側にある機器で熱が発生した場合は、逆に配置することで下部に熱が伝わるのを抑制することができるので、冷却対象物が加熱されることを抑制することができる。 In another aspect, the cooling device of the present invention is such that the temperature at which the ceramic material exhibits latent heat is highest on the surface in contact with the object to be cooled (i.e., the lower part), and gradually decreases with increasing distance from the surface. It can be configured to be the lowest on the surface opposite to the surface in contact with (ie, the upper portion) (FIG. 1 (d)). By adopting such a configuration, it is possible to efficiently transfer heat to the upper portion, as described above, so that it is possible to cool the cooling target with high efficiency and high response. On the other hand, when heat is generated around the object to be cooled, particularly the equipment on the upper side, it is possible to prevent the heat from being transmitted to the lower part by placing it in reverse, so that the object to be cooled is heated. Can be suppressed.
　好ましい態様において、上記セラミックス材料は、粒子（粉末）状であり得る。セラミックス材料を粒子として用いることにより、相転移を繰り返した場合にもクラックの発生を抑制することができ、冷却デバイスの耐久性が高くなる。 In a preferred embodiment, the ceramic material may be in the form of particles (powder). By using the ceramic material as particles, the occurrence of cracks can be suppressed even when the phase transition is repeated, and the durability of the cooling device is enhanced.
　上記セラミックス材料の粒子の粒度は、特に限定されないが、例えば平均粒子径が、０．２～５０μｍであり、好ましくは、０．５～５０μｍである。かかる平均粒子径は、レーザー回折・散乱式 粒子径・粒度分布測定装置または電子走査顕微鏡を用いて測定することができる。平均粒子系は、取り扱いの容易性の観点から、０．５μｍ以上であることが好ましく、粒子間の空隙率を小さくする観点から、１０μｍ以下であることが好ましい。 The particle size of the ceramic material particles is not particularly limited. For example, the average particle size is 0.2 to 50 μm, preferably 0.5 to 50 μm. Such an average particle diameter can be measured using a laser diffraction / scattering soot particle diameter / particle size distribution measuring apparatus or an electronic scanning microscope. The average particle system is preferably 0.5 μm or more from the viewpoint of ease of handling, and is preferably 10 μm or less from the viewpoint of reducing the porosity between particles.
　一の態様において、本発明の冷却デバイスは、金属粒子（例えば、粉末）を含んでいてもよい。この金属粒子は、上記セラミックス材料よりも熱伝導率が高いので、金属粒子を用いることにより冷却対象物の熱を効率的に冷却デバイスの広範な領域に伝えることが可能になる。また、この場合、化学的、物理的手法を用いてセラミックス粒子に金属をコーティングした紛体を使用してもよい。 In one embodiment, the cooling device of the present invention may include metal particles (for example, powder). Since the metal particles have higher thermal conductivity than the ceramic material, the heat of the object to be cooled can be efficiently transmitted to a wide area of the cooling device by using the metal particles. In this case, a powder obtained by coating a ceramic particle with a metal using a chemical or physical method may be used.
　上記金属粒子は、セラミックス材料と接触していればよく、例えば、冷却デバイスに分散して存在し、均一で存在しても不均一で存在してもよい。冷却デバイスがセラミックス層から構成される場合、すべてのセラミックス層に存在してもよく、または一部のセラミックス層に存在してもよい。層を形成するセラミックス材料が塊である場合はそこに分散され得、層を形成するセラミックス材料が粒子である場合は、セラミックス材料の粒子と金属粒子との混合物として存在し得る。 The metal particles need only be in contact with the ceramic material. For example, the metal particles may be dispersed in the cooling device and may be present uniformly or non-uniformly. When the cooling device is composed of ceramic layers, it may be present in all ceramic layers, or may be present in some ceramic layers. When the ceramic material forming the layer is a lump, it can be dispersed therein, and when the ceramic material forming the layer is a particle, it can be present as a mixture of particles of ceramic material and metal particles.
　上記金属粒子としては、上記セラミックス材料よりも熱伝導率が高いものであれば特に限定されず、例えば、スズ、ニッケル、銅、銀およびアルミニウムなどからなる粒子が挙げられる。この金属粒子は、単独で用いてもよく、または２種以上の金属粒子を組み合わせて用いてもよい。好ましい金属粒子は、スズ、銀、または銅粒子である。 The metal particles are not particularly limited as long as they have higher thermal conductivity than the ceramic material, and examples thereof include particles made of tin, nickel, copper, silver, aluminum, and the like. These metal particles may be used alone or in combination of two or more metal particles. Preferred metal particles are tin, silver, or copper particles.
　上記金属粒子（粉末）の粒度は、特に限定されないが、例えば平均粒子径が、０．５～１００μｍであり、好ましくは、１～５０μｍである。かかる平均粒子径は、レーザー回折・散乱式 粒子径・粒度分布測定装置または走査電子顕微鏡を用いて測定することができる。平均粒子系は、取り扱いの容易性の観点から、１μｍ以上であることが好ましく、粒子間の空隙率を小さくする観点から、５０μｍ以下であることが好ましい。 The particle size of the metal particles (powder) is not particularly limited. For example, the average particle size is 0.5 to 100 μm, preferably 1 to 50 μm. Such an average particle diameter can be measured using a laser diffraction / scattering soot particle diameter / particle size distribution measuring apparatus or a scanning electron microscope. The average particle system is preferably 1 μm or more from the viewpoint of ease of handling, and is preferably 50 μm or less from the viewpoint of reducing the porosity between particles.
　上記セラミックス材料と金属粒子の混合比は、特に限定されないが、例えば、体積比で８：２～２：８であり、好ましくは６：４～３：７である。なお、セラミックス材料と金属粒子の体積比は、それぞれの重量を測定して理論密度から体積を算出することにより得ることができる。金属粒子の割合を多くすることにより、冷却デバイス内部の熱伝導性を向上させることができ、冷却効率を高めることができる。さらに、成形後の冷却デバイスの強度を高めることができる。他方、セラミックス材料の割合を多くすることにより、吸収できる熱量を大きくすることができる。 The mixing ratio of the ceramic material and the metal particles is not particularly limited. For example, the volume ratio is 8: 2 to 2: 8, preferably 6: 4 to 3: 7. The volume ratio between the ceramic material and the metal particles can be obtained by measuring the respective weights and calculating the volume from the theoretical density. By increasing the ratio of the metal particles, the thermal conductivity inside the cooling device can be improved, and the cooling efficiency can be increased. Furthermore, the strength of the cooling device after molding can be increased. On the other hand, the amount of heat that can be absorbed can be increased by increasing the proportion of the ceramic material.
　一の態様において、本発明の冷却デバイスは、樹脂を含んでいてもよい。冷却デバイスに樹脂を含有させることにより、冷却デバイスに柔軟性を与えることができ、また、冷却デバイスの強度を高めることができる。また樹脂が高抵抗であるため複合化により冷却デバイスの抵抗を高めることができ、回路のショートや電波の干渉などを抑制することが可能となる利点もある。 In one embodiment, the cooling device of the present invention may contain a resin. By including a resin in the cooling device, flexibility can be given to the cooling device, and the strength of the cooling device can be increased. In addition, since the resin has a high resistance, the resistance of the cooling device can be increased by compounding, and there is an advantage that it is possible to suppress a short circuit or interference of radio waves.
　上記樹脂としては、特に限定されるものではないが、例えばアクリル系樹脂、エポキシ、ポリエステル、シリコン、ポリウレタン、ポリエチレン、ポリプロピレン、ポリスチレン、ナイロン、ポリカーボネート、ポリブチレンテレフタレート等が挙げられる。 The resin is not particularly limited, and examples thereof include acrylic resin, epoxy, polyester, silicon, polyurethane, polyethylene, polypropylene, polystyrene, nylon, polycarbonate, and polybutylene terephthalate.
　上記樹脂の含有量は、特に限定されないが、粒子（金属粒子および存在する場合にはセラミックス材料の粒子を含む）間の空隙を埋めることができる量以上であることが好ましく、例えば、セラミックス材料と金属粒子の合計１００体積部に対して、１０～６０体積部が好ましい The content of the resin is not particularly limited, but is preferably equal to or more than an amount capable of filling a gap between particles (including metal particles and ceramic material particles, if present). 10 to 60 parts by volume is preferable with respect to 100 parts by volume in total of the metal particles.
　一の態様において、本発明の冷却デバイスは、セラミックス材料よりも高い熱伝導率を有する材料（以下、「高熱伝導材料」ともいう）から構成される熱伝導部を有していてもよい。この熱伝導部は、冷却対象物で生じた熱を効率的に冷却デバイスの広範な領域に伝える機能を有する。 In one embodiment, the cooling device of the present invention may have a heat conducting portion made of a material having a higher thermal conductivity than the ceramic material (hereinafter also referred to as “high heat conducting material”). The heat conducting unit has a function of efficiently transferring heat generated in the object to be cooled to a wide area of the cooling device.
　上記高熱伝導材料としては、上記セラミックス材料よりも高い熱伝導率を有する材料であれば特に限定されないが、金属材料および樹脂が挙げられ、好ましくは金属材料やその複合材料、またグラファイト、グラフェンシートが用いられる。 The high thermal conductivity material is not particularly limited as long as it has a higher thermal conductivity than the ceramic material, and examples thereof include metal materials and resins, preferably metal materials and composite materials thereof, graphite, and graphene sheets. Used.
　上記高熱伝導材料としては、上記セラミックス材料よりも高い熱伝導率を有する材料であれば特に限定されないが、金属材料、樹脂、ＡｌＮなどの窒化物およびＡｌ２Ｏ３などの酸化物が挙げられ、好ましくは金属材料やその複合材料、またグラファイト、グラフェンである。 The high thermal conductivity material is not particularly limited as long as it has a higher thermal conductivity than the ceramic material, but includes metal materials, resins, nitrides such as AlN, and oxides such as Al 2 O 3 , Metal materials and composite materials thereof, graphite, and graphene are preferable.
　上記金属材料としては、特に限定されるものではないが、例えば、スズ、ニッケル、銅、ビスマス、銀、鉄およびアルミニウムまたはそれらを含む合金等が挙げられる。この金属材料は、上記金属粒子と同じ金属であっても、異なっていてもよい。これらの金属材料は、単独で用いてもよく、または２種以上を組み合わせて用いてもよい。 The metal material is not particularly limited, and examples thereof include tin, nickel, copper, bismuth, silver, iron, aluminum, and alloys containing them. This metal material may be the same metal as the metal particles or may be different. These metal materials may be used alone or in combination of two or more.
　上記高熱伝導部は、冷却対象物で生じた熱を冷却デバイスの広範な領域に伝えることが可能であれば、その形状および配置は特に限定されない。 The shape and arrangement of the high heat conduction part are not particularly limited as long as the heat generated in the object to be cooled can be transmitted to a wide area of the cooling device.
　好ましい態様において、上記熱伝導部は、冷却対象物との接触部を有し、該接触部から離れた位置においてセラミックス材料と接触するように配置される。このように熱伝導部を配置することにより、より効率的に熱を冷却デバイスの広範な領域に伝えることができる。 In a preferred embodiment, the heat conducting part has a contact part with the object to be cooled, and is arranged so as to contact the ceramic material at a position away from the contact part. By arranging the heat conducting portion in this way, heat can be more efficiently transferred to a wide area of the cooling device.
　別の好ましい態様において、上記熱伝導部は、冷却デバイスの周囲を取り囲むように配置され、即ち、セラミックス材料および金属粒子をパッケージングするように配置することができる。このような形態とすることにより、冷却デバイスの強度を高めることができ、また、熱を外部に放出する能力を高めることができる。 In another preferred embodiment, the heat conducting part is disposed so as to surround the periphery of the cooling device, that is, can be disposed so as to package the ceramic material and the metal particles. By setting it as such a form, the intensity | strength of a cooling device can be raised and the capability to discharge | release heat outside can be improved.
　好ましい態様において、本発明の冷却デバイスは弾性を有し得る。弾性を有することにより、例えば他の部材に挟むことによる冷却デバイスの固定をより容易かつ安定に行うことができる。本発明の冷却デバイスに弾性を与える方法は、特に限定されないが、例えば樹脂を含有させる方法が挙げられる。 In a preferred embodiment, the cooling device of the present invention may have elasticity. By having elasticity, for example, the cooling device can be fixed more easily and stably by being sandwiched between other members. The method for imparting elasticity to the cooling device of the present invention is not particularly limited, and examples thereof include a method of containing a resin.
　本発明の冷却デバイスの形状は、特に限定されず、例えば、ブロック状またはシート状のいずれであってもよい。必要に応じて、デバイス上面に凹凸加工をして表面積を大きくしてもよい。 The shape of the cooling device of the present invention is not particularly limited, and may be, for example, a block shape or a sheet shape. If necessary, the surface of the device may be roughened to increase the surface area.
　冷却デバイスをブロック状とすることにより、全体の体積が大きくなり、より多くの熱を吸収することができる。 ¡By making the cooling device into a block shape, the entire volume is increased and more heat can be absorbed.
　冷却デバイスをシート状とすることにより、表面積が増加するので、吸収した熱を外部に放出しやすくなる。また、シート状とした場合、樹脂を含有せしめることにより、冷却デバイスの柔軟性を高めることができ、設置に関する自由度が向上する。また、これにより、一つのデバイスで複数の冷却対象物の冷却をおこなうこともできる。 ∙ By making the cooling device into a sheet shape, the surface area increases, so it becomes easier to release the absorbed heat to the outside. Moreover, when it is set as a sheet form, the softness | flexibility of a cooling device can be improved by containing resin, and the freedom degree regarding installation improves. Thereby, it is also possible to cool a plurality of cooling objects with one device.
　本発明の冷却デバイスの製造方法は、特に限定されず、公知の方法、例えば、セラミックス材料がセラミックス層を構成する場合、相転移を示す温度が異なるセラミックス材料を用いて、別個にセラミックス層を形成し、これを圧着することにより作製することができる。別法として、相転移を示す温度が異なるセラミックス材料を含むペーストを積層して、圧縮成形して積層体を得ることができる。所望により、圧縮成形後に、熱処理して積層体を焼結してもよい。この場合、焼成中に転移温度制御のために添加したＷ等が相互拡散することにより転移温度が連続的に変化した冷却デバイスを作製することができる。 The manufacturing method of the cooling device of the present invention is not particularly limited. For example, when the ceramic material constitutes the ceramic layer, the ceramic layer is separately formed using ceramic materials having different temperatures indicating phase transition. And it can produce by crimping | bonding this. Alternatively, pastes containing ceramic materials having different temperatures exhibiting phase transition can be laminated and compression molded to obtain a laminate. If desired, the laminate may be sintered by heat treatment after compression molding. In this case, it is possible to manufacture a cooling device in which the transition temperature is continuously changed by mutual diffusion of W or the like added for controlling the transition temperature during firing.
　本発明の冷却デバイスは、所望の形状に成形することができ、さらに柔軟性を与えることもできるので、冷却デバイスとしての機能を有しつつ、基板、ケースまたは緩衝材等の他の部材としても利用することができる。 Since the cooling device of the present invention can be molded into a desired shape and can also be given flexibility, it can function as a cooling device and can also be used as another member such as a substrate, a case, or a cushioning material. Can be used.
　実験例：
・焼結セラミックス冷却デバイスの作製
　セラミックス原料として、三酸化バナジウム（Ｖ２Ｏ３）、五酸化バナジウム（Ｖ２Ｏ５）、および酸化タングステン（ＷＯ３）を用い、これらをＶ：Ｗ：Ｏ＝０．９９５：０．００５：２（モル比）となるように秤量し、乾式混合した。その後、窒素／水素／水雰囲気下で１０００℃、４時間熱処理し、セラミックス材料としてＶ０．９９５Ｗ０．００５Ｏ２（０．５ａｔ％ＷドープＶＯ２）の粉末を調製した。 Experimental example:
-Production of sintered ceramic cooling device Vanadium trioxide (V 2 O 3 ), vanadium pentoxide (V 2 O 5 ), and tungsten oxide (WO 3 ) were used as ceramic raw materials, and these were expressed as V: W: O = It weighed so that it might become 0.995: 0.005: 2 (molar ratio), and it dry-mixed. Thereafter, heat treatment was performed at 1000 ° C. for 4 hours in a nitrogen / hydrogen / water atmosphere to prepare a powder of V 0.995 W 0.005 O 2 (0.5 at% W-doped VO 2 ) as a ceramic material.
　次に、純水、部分安定化ジルコニウム（Partial Stabilized Zirconia；ＰＳＺ）ボール、分散剤（サンノプコ製：ＳＮ５４６８）および上記で得られたセラミックス材料の粉末をポリポットに加えて、２４時間粉砕混合を行い、その後アクリル系バインダー、可塑剤および消泡剤を加え、再度２時間混合を行い、シート成形用スラリーを得た。 Next, pure water, partially stabilized zirconium (PSZ) balls, a dispersant (manufactured by San Nopco: SN5468) and the ceramic material powder obtained above are added to a polypot and pulverized and mixed for 24 hours. Thereafter, an acrylic binder, a plasticizer and an antifoaming agent were added and mixed again for 2 hours to obtain a sheet forming slurry.
　次に、ドクターブレード法を使用し、シート成形用スラリーをシート成形して、グリーンシートを作製し、その後短冊カットし、圧着プロセスにより、セラミックス単板を作製した。このセラミックス単板を、３００℃大気中で脱脂処理に付し、その後窒素／水素／水雰囲気下で、１０００℃で４時間熱処理して焼結させて、２０ｍｍ×２０ｍｍ×５ｍｍのサイズの焼結セラミックス単板の冷却デバイスを作製した。 Next, using a doctor blade method, a sheet forming slurry was formed into a sheet to produce a green sheet, then cut into strips, and a ceramic single plate was produced by a crimping process. This ceramic single plate is subjected to a degreasing treatment in the atmosphere at 300 ° C., and then sintered by heat treatment at 1000 ° C. for 4 hours in a nitrogen / hydrogen / water atmosphere to obtain a size of 20 mm × 20 mm × 5 mm. A ceramic single plate cooling device was fabricated.
・示差走査熱量測定
　上記で得られたセラミックス単板の冷却デバイスについて、示差走査熱量測定（Differential scanning calorimetry：ＤＳＣ）により、０℃→１００℃→０℃の温度掃引で、熱の出入り（吸熱および発熱）を評価した。結果を図２に示す。図２から、得られたセラミックス材料は、加温時には５０℃～６０℃付近で吸熱し、冷却時には４０～５０℃付近で放熱することが確認された。 ・ Differential scanning calorimetry About the cooling device of the ceramic single plate obtained above, by differential scanning calorimetry (DSC), heat input and output (endothermic and Exotherm) was evaluated. The results are shown in FIG. From FIG. 2, it was confirmed that the obtained ceramic material absorbs heat at around 50 ° C. to 60 ° C. during heating and dissipates heat at around 40-50 ° C. during cooling.
・冷却試験
　発熱体として、到達温度が約６０℃のＰＴＣ（positive temperature coefficient）ヒーターを使用し、ＰＴＣヒーター表面に熱伝導グリスを塗布、そして極細Ｋ熱電対を張り付けてその上から上記で作製した焼結セラミックス単板の冷却デバイスを押しつけて固定した。さらに冷却デバイスの上面（ＰＴＣヒーターと接触している面と反対の面）にも極細Ｋ熱電対を張り付けた。また、基準用に別のＰＴＣヒーターの表面に熱伝導グリスを塗布し、極細Ｋ熱電対を張り付けた（冷却デバイスなし）。 ・ Cooling test A PTC (positive temperature coefficient) heater with an ultimate temperature of about 60 ° C. was used as a heating element, and heat conduction grease was applied to the surface of the PTC heater, and an ultrafine K thermocouple was applied thereon, and the above was produced from above. The sintered ceramic single plate cooling device was pressed and fixed. Further, an ultrafine K thermocouple was attached to the upper surface of the cooling device (the surface opposite to the surface in contact with the PTC heater). In addition, heat conduction grease was applied to the surface of another PTC heater for reference, and an ultrafine K thermocouple was attached (no cooling device).
　上記の冷却デバイス有りのＰＴＣヒーターおよび冷却デバイスなしのＰＴＣヒーターについて、直流電源を用いてＰＴＣヒーターに定格電流を通電した状態で１０分間、ついで、通電を止めて２０分間、ヒーターと冷却デバイスの接触面の温度、および冷却デバイスの上面の温度を測定した。結果を図３に示す。 For the above PTC heaters with and without cooling devices, contact the heaters with the cooling device for 10 minutes with the rated current applied to the PTC heaters using a DC power supply and then for 20 minutes with the current turned off. The temperature of the surface and the temperature of the upper surface of the cooling device were measured. The results are shown in FIG.
　図３に示されるように、焼結セラミックス単板の冷却デバイスを用いることにより、この冷却デバイスを用いない場合と比較して、ＰＴＣヒーターの表面（接触面）温度がわずかに低下していることが確認された。しかしながら、冷却デバイス上面の温度は、接触面との温度差が大きく、熱吸収に十分寄与できていないことが確認された。これは、図４の矢印で示されるように、ＰＴＣヒーター４の熱は、これと接触している焼結セラミックス単板２の下部（図４のｘ部分）に伝わるが、ｘ部分が相転移に要する熱を吸収している間、このｘ部分のセラミックス材料から焼結セラミックス単板の上部（図４のｙ部分）に伝わる熱量が低下するのが原因であると考えられる。その結果、ＰＴＣヒーターに通電後しばらくは冷却効果が見られるが、４００秒後には、冷却デバイスの上面の温度が低いにもかかわらず、冷却効果はほとんど見られなくなり、冷却デバイスを用いるメリットが小さいことが確認された。 As shown in FIG. 3, the surface (contact surface) temperature of the PTC heater is slightly lowered by using the sintered ceramic single plate cooling device as compared with the case where this cooling device is not used. Was confirmed. However, it has been confirmed that the temperature of the upper surface of the cooling device has a large temperature difference from the contact surface and does not sufficiently contribute to heat absorption. As indicated by the arrows in FIG. 4, the heat of the PTC heater 4 is transmitted to the lower part of the sintered ceramic single plate 2 that is in contact with the PTC heater 4 (the x part in FIG. 4). It is thought that this is because the amount of heat transferred from the ceramic material of the x portion to the upper portion of the sintered ceramic single plate (y portion in FIG. 4) is reduced while absorbing the heat required for. As a result, the cooling effect is seen for a while after the PTC heater is energized, but after 400 seconds, the cooling effect is hardly seen even though the temperature of the upper surface of the cooling device is low, and the merit of using the cooling device is small. It was confirmed.
　実施例
　上記実験例と同様にして、Ｖ：Ｗ（モル比）が下記表１に示す割合となるように、セラミックス材料Ａ～Ｃの粉末を調製した。 Examples In the same manner as in the above experimental examples, powders of ceramic materials A to C were prepared so that V: W (molar ratio) was a ratio shown in Table 1 below.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
　得られたセラミックス材料の粉末、純水、部分安定化ジルコニウム（Partial Stabilized Zirconia；ＰＳＺ）ボール、および分散剤をポリポットに加えて、２４時間粉砕混合を行い、その後アクリル系バインダー、可塑剤および消泡剤を加え、再度２時間混合を行い、セラミックス材料Ａ～Ｃに対応するシート成形用スラリーＡ～Ｃを得た。 The resulting ceramic material powder, pure water, partially stabilized zirconium (PSZ) balls, and a dispersant are added to a polypot and mixed for 24 hours, followed by acrylic binder, plasticizer and antifoam. The agent was added and mixed again for 2 hours to obtain sheet forming slurries A to C corresponding to the ceramic materials A to C.
　次に、ドクターブレード法を使用し、シート成形用スラリーＡ～Ｃの各々を、シート成形して、グリーンシートＡ～Ｃを作製し、その後グリーンシートＡ～Ｃのそれぞれを短冊カットし、約１．６ｍｍに積層し、積層したグリーンシートＡ～Ｃを、Ａ～Ｃの順番で圧着、カットして、サイズ２０ｍｍ×２０ｍｍ×５ｍｍの積層体を作製した。 Next, using the doctor blade method, each of the sheet forming slurries A to C is formed into a sheet to produce green sheets A to C. Thereafter, each of the green sheets A to C is cut into strips, and about 1 The green sheets A to C were laminated to 6 mm, and the laminated green sheets A to C were pressure-bonded and cut in the order of A to C to prepare a laminate having a size of 20 mm × 20 mm × 5 mm.
　比較例１
　グリーンシートＡのみを積層する以外は、実施例１と同様にして、サイズ２０ｍｍ×２０ｍｍ×５ｍｍの比較例１の積層体を得た。 Comparative Example 1
A laminate of Comparative Example 1 having a size of 20 mm × 20 mm × 5 mm was obtained in the same manner as Example 1 except that only the green sheet A was laminated.
（評価）
・冷却試験
　発熱体として、到達温度が約６０℃のＰＴＣヒーターを使用し、ヒーター表面に熱伝導グリスを塗布、そして極細Ｋ熱電対を張り付けてその上から上記で作製した比較例１および実施例１の冷却デバイスを押しつけて固定した。なお、実施例１の冷却デバイスは、グリーンシートＣ側を冷却デバイス側とした。また、基準用に、冷却デバイスなしのヒーター表面にも極細Ｋ熱電対を張り付けた。 (Evaluation)
Cooling test As a heating element, a PTC heater having an ultimate temperature of about 60 ° C. was used, heat conduction grease was applied to the heater surface, and an ultrafine K thermocouple was attached thereto. One cooling device was pressed and fixed. In the cooling device of Example 1, the green sheet C side was the cooling device side. For reference, an extra fine K thermocouple was attached to the surface of the heater without a cooling device.
　直流電源を用いてＰＴＣヒーターに定格電流を通電し、２００秒後および６００秒後でのＰＴＣヒーター表面の温度を測定し、冷却効果を評価した。結果を表２に示す。 The rated current was applied to the PTC heater using a DC power supply, and the temperature of the PTC heater surface after 200 seconds and 600 seconds was measured to evaluate the cooling effect. The results are shown in Table 2.
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
　上記表に示されるように、１種のセラミックス材料のみを用いた比較例１の冷却デバイスは、ＰＴＣヒーターに通電後２００秒後の時点では冷却効果を示すが、６００秒後には冷却効果が見られない。これは実験例で記載したように、セラミックス材料が熱を吸収している間は、熱伝導が抑制され、冷却デバイスの上面付近が、熱吸収に十分寄与できていないことが原因と考えられる。 As shown in the above table, the cooling device of Comparative Example 1 using only one kind of ceramic material shows a cooling effect at 200 seconds after energizing the PTC heater, but after 600 seconds, the cooling effect is seen. I can't. As described in the experimental example, this is considered to be because heat conduction is suppressed while the ceramic material is absorbing heat, and the vicinity of the upper surface of the cooling device cannot sufficiently contribute to heat absorption.
　一方、３種のセラミックス材料を用いた実施例１の冷却デバイスは、比較例１の冷却デバイスと比較して、２００秒後の冷却効果が大きく、また、６００秒後も十分に冷却効果を示すことが確認された。 On the other hand, the cooling device of Example 1 using three kinds of ceramic materials has a larger cooling effect after 200 seconds than the cooling device of Comparative Example 1, and also exhibits a sufficient cooling effect after 600 seconds. It was confirmed.
　上記の結果から、異なる温度で相転移するセラミックス材料を、その相転移を示す温度の順に積層し、相転移を示す温度が低い層を冷却対象物側に配置することにより、冷却効果を改善することが可能となることが確認された。これは、各層の相転移を示す温度を段階的にすることにより、冷却対象物で生じた熱を、効率よく上層に伝えることができるためと考えられる。 From the above results, ceramic materials that undergo phase transition at different temperatures are stacked in the order of the temperature showing the phase transition, and the cooling effect is improved by arranging a layer with a low temperature showing the phase transition on the cooling object side. It was confirmed that it would be possible. This is considered to be because heat generated in the object to be cooled can be efficiently transferred to the upper layer by making the temperature showing the phase transition of each layer stepwise.
　本発明の冷却デバイスは、例えば、熱対策問題が顕著化している小型通信端末の冷却デバイスとして利用することができる。 The cooling device of the present invention can be used, for example, as a cooling device for a small communication terminal in which a thermal countermeasure problem has become prominent.
　　２　…　焼結セラミックス単板
　　４　…　ＰＴＣヒーター 2 ... Sintered ceramic single plate 4 ... PTC heater

Claims (10)

  1. 　熱を吸収するセラミックス材料を含んで成る冷却デバイスであって、冷却対象物と接触する面から第１の距離にあるセラミックス材料の潜熱を示す温度が、冷却対象物と接触する面から第２の距離にあるセラミックス材料の潜熱を示す温度と異なることを特徴とする、冷却デバイス。 A cooling device comprising a ceramic material that absorbs heat, wherein the temperature indicative of the latent heat of the ceramic material at a first distance from the surface in contact with the object to be cooled is second from the surface in contact with the object to be cooled. A cooling device, characterized in that it is different from the temperature indicating the latent heat of the ceramic material at a distance.
  2. 　セラミックス材料から構成される２つまたはそれ以上のセラミックス層が積層されて成り、各セラミックス層を構成するセラミックス材料の潜熱を示す温度がそれぞれ異なることを特徴とする、請求項１に記載の冷却デバイス。 2. The cooling device according to claim 1, wherein two or more ceramic layers made of ceramic materials are laminated, and the temperatures indicating the latent heat of the ceramic materials constituting each ceramic layer are different from each other. .
  3. 　セラミックス材料の潜熱を示す温度が、冷却対象物と接触する面において最も高く、前記面から離れるに従って低くなることを特徴とする、請求項１または２に記載の冷却デバイス。 3. The cooling device according to claim 1, wherein a temperature indicating latent heat of the ceramic material is highest on a surface in contact with an object to be cooled and decreases as the distance from the surface increases.
  4. 　セラミックス材料が、バナジウムＶおよびＭ（ここに、Ｍは、Ｗ、Ｔａ、ＭｏおよびＮｂから選ばれる少なくとも一種である）を含む酸化物であって、ＶとＭの合計を１００モル部としたときのＭの含有モル部が約０モル部以上約５モル部以下であることを特徴とする、請求項１～３のいずれかに記載の冷却デバイス。 When the ceramic material is an oxide containing vanadium V and M (where M is at least one selected from W, Ta, Mo and Nb), and the total of V and M is 100 mol parts The cooling device according to any one of claims 1 to 3, wherein the molar part of M is from about 0 to about 5 parts by mole.
  5. 　セラミックス材料が、Ａ（ここに、ＡはＬｉまたはＮａである）およびバナジウムＶを含む酸化物であって、Ｖを１００モル部としたときのＡの含有モル部が約５０モル部以上約１００モル部以下であることを特徴とする、請求項１～３のいずれかに記載の冷却デバイス。 The ceramic material is an oxide containing A (here, A is Li or Na) and vanadium V, and when V is 100 mole parts, the content mole part of A is about 50 mole parts or more and about 100 mole parts. The cooling device according to any one of claims 1 to 3, wherein the cooling device is in a molar part or less.
  6. 　セラミックス材料が、式：
    　　　Ｖ１－ｘＭｘＯ２
    （式中、Ｍは、Ｗ、Ｔａ、ＭｏまたはＮｂであり、ｘは、０以上０．０５以下である）
    または、式：
    　　　ＡｙＶＯ２
    （式中、Ａは、ＬｉまたはＮａであり、ｙは、０．５以上１．０以下である）
    で表される１種またはそれ以上の材料を含むことを特徴とする、請求項１～３のいずれかに記載の冷却デバイス。     Ceramic material has the formula:
    V 1-x M x O 2
    (In the formula, M is W, Ta, Mo or Nb, and x is 0 or more and 0.05 or less)
    Or the formula:
    A y VO 2
    (In the formula, A is Li or Na, and y is 0.5 or more and 1.0 or less)
    The cooling device according to any one of claims 1 to 3, characterized in that it comprises one or more materials represented by:
  7. 　セラミックス材料が、粒子状であることを特徴とする、請求項１～６のいずれかに記載の冷却デバイス。 The cooling device according to any one of claims 1 to 6, wherein the ceramic material is in the form of particles.
  8. 　さらに、金属粒子を含むことを特徴とする、請求項１～７のいずれかに記載の冷却デバイス。 The cooling device according to any one of claims 1 to 7, further comprising metal particles.
  9. 　さらに、樹脂を含んで成ることを特徴とする、請求項１～８のいずれかに記載の冷却デバイス。 The cooling device according to any one of claims 1 to 8, further comprising a resin.
  10. 　さらに、セラミックス材料よりも高い熱伝導率を有する材料から構成される熱伝導部を有して成ることを特徴とする、請求項１～９のいずれかに記載の冷却デバイス。 The cooling device according to any one of claims 1 to 9, further comprising a heat conducting portion made of a material having a higher thermal conductivity than the ceramic material.
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WO2016063479A1 (en) * 2014-10-22 2016-04-28 株式会社デンソー Laminated heat storage material
JP2016069554A (en) * 2014-09-30 2016-05-09 株式会社デンソー Heat storage unit and heat storage system

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JP5854363B2 (en) * 2013-12-11 2016-02-09 富士高分子工業株式会社 Thermal storage composition
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