JP6995370B2 - Thermoelectric converters and electronic devices - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act (1) Publication name 2016 The 63rd Japan Society of Applied Physics Spring Academic Lecture Proceedings Proceedings Organizer name Japan Society of Applied Physics Publication date March 3, 2016 (2) ) Meeting name The 63rd Japan Society of Applied Physics Spring Academic Lecture Organizer name Japan Society of Applied Physics Date March 21, 2016

The present invention relates to a thermoelectric conversion device and an electronic device, for example, a thermoelectric conversion device and an electronic device having a thermoelectric thin film.

A thermoelectric converter (or thermoelectric generator) called a thermoelectric generator (TEG), which integrates a large number of Zeebeck elements composed of thermoelectric materials, generates electricity using the exhaust heat of power plants, factories, and automobiles. It is expected as a technology. Recently, a small thermoelectric converter called a micro thermoelectric generator (μTEG) is expected as an energy harvesting element that can be used for wearable devices and sensor nodes. Further, in such a μTEG, power generation using the waste heat of a microprocessor or a system-on-chip (SoC) can be considered.

By alternately forming a large number of columnarized n-type and p-type thermoelectric materials on the lower surface of the upper substrate and the upper surface of the lower substrate, respectively, and joining the upper substrate and the lower substrate. , ΜTEG is known to be produced (for example, Patent Document 1). In this structure, the directions of heat flow and current in the thermoelectric layer are in the normal direction of the substrate. Since this type of μTEG has a structure in which a large number of π-type Zeebeck elements are connected, it will be referred to as π-type in the following.

A structure is described in which n-type and p-type strip-shaped thermoelectric thin films are alternately arranged in the width direction of the strips, and the ends of the thermoelectric thin films in the stretching direction are connected alternately. In this structure, the directions of heat flow and current in the thermoelectric thin film are in the length direction of the strip. This type of μTEG is hereinafter referred to as an inplane type.

U.S. Pat. No. 7,402,910

By using a thin-film thermoelectric material, the thermoelectric conversion device can be miniaturized and highly integrated. However, when a thin-film thermoelectric material is used for the π-type or in-plane type μTEG, the thermal resistance and the electric resistance have a trade-off relationship, and it is difficult to realize a high-output thermoelectric conversion device.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a compact and high-power thermoelectric conversion device and an electronic device.

The present invention includes the first thermoelectric thin film and the second thermoelectric thin film having conductive types alternately provided in the first direction parallel to the surfaces of the first thermoelectric thin film and the second thermoelectric thin film, and the first thermoelectric thin film. A first connecting layer and a second connecting layer, which are electrically and thermally connected to the first thermoelectric thin film and the second thermoelectric thin film between the thermoelectric thin film and the second thermoelectric thin film, and are alternately provided in the first direction. It comprises a connecting layer and a first heat conductive layer and a second heat conductive layer that are thermally connected to the first connecting layer and the second connecting layer, respectively, and extend in a second direction intersecting the surface. The first heat conductive layer and the second heat conductive layer are provided on opposite sides to the surfaces of the first thermoelectric thin film and the second thermoelectric thin film, and the first heat conductive layer penetrates the first heat conductive layer. (1) A solid first insulator having a lower thermal conductivity than the heat conductive layer, a solid second insulator through which the second heat conductive layer penetrates, and a solid second insulator having a lower thermal conductivity than the second heat conductive layer, and the first. It comprises a heat conductive layer and a first base and a second base that are thermally connected to the second heat conductive layer, respectively, and the first base and the first insulator are between the first heat conductive layer. The second base portion and the second insulator are thermoelectric conversion devices having a first groove in the above, and having a second groove between the second heat conductive layers.

In the above configuration, the layer including the first thermoelectric thin film, the second thermoelectric thin film, the first connecting layer, the second connecting layer, the first heat conductive layer and the second heat conductive layer intersects the surface. A plurality of layers are laminated in the direction, and the first heat conductive layer contained in one of the adjacent layers among the plurality of layers and the second heat conductive layer contained in the other of the adjacent layers are thermally connected. Can be configured as

In the above configuration, the first thermoelectric thin film, the second thermoelectric thin film, the first connecting layer, the second connecting layer, and the first heat conductive layer are provided between the first base portion and the second base portion. And the thermoelectric conversion unit provided with the second heat conductive layer, and the first heat conductive layer and the second heat conductive layer are connected to the first base portion and the second base portion, respectively, and the first base portion and the first base portion. It is provided between the two bases and outside the thermoelectric conversion unit, and has a thermal conductivity smaller than that of the first thermoelectric thin film, the second thermoelectric thin film, the first base portion, and the second base portion. The first base may be thermally connected to the surface of a living body of a constant temperature animal, and the second base may be thermally connected to the air .

INDUSTRIAL APPLICABILITY The present invention is a first thermoelectric material provided between a first base portion, a second base portion, the first base portion and the second base portion, and between the first connection layer and the second connection layer. And the second thermoelectric material having a conductive type opposite to that of the first thermoelectric material are alternately connected in series via the first connecting layer and the second connecting layer, and the first connecting layer and the first connecting layer are connected in series. The two connecting layers are between the thermoelectric conversion unit thermally connected to the first base portion and the second base portion, and between the first base portion and the second base portion, respectively, and are outside the thermoelectric conversion unit in a plan view. The thermal insulator is provided with the first thermoelectric material, the second thermoelectric material, and a thermal insulator having a thermal conductivity smaller than the thermal conductivity of the first base portion and the second base portion. In a region outside the thermoelectric conversion unit in plan view, the first base portion and the second base portion are in contact with each other, and in plan view, the area of the thermoelectric conversion unit is the first via the thermoelectric conversion unit and the thermal insulator . It is a thermoelectric conversion device characterized in that the area of the region where the base portion and the second base portion face each other is 1/100 or less.

In the above configuration, the thermal insulator may be configured to be a solid layer. In the above configuration, the thermal insulator may be configured to be a gas layer or a vacuum having a pressure lower than the atmospheric pressure.

The present invention is a first thermoelectric material provided between the first base, the second base, the first base and the second base, and between the first connecting layer and the second connecting layer. And the second thermoelectric material having a conductive type opposite to that of the first thermoelectric material are alternately connected in series via the first connecting layer and the second connecting layer, and the first connecting layer and the first connecting layer are connected in series. The two connecting layers are provided between the thermoelectric conversion unit thermally connected to the first base portion and the second base portion, respectively, and between the first base portion and the second base portion, and outside the thermoelectric conversion unit. A thermal insulator that is a gas layer or vacuum having a pressure lower than atmospheric pressure and that contacts the first and second bases in the outer region of the thermoelectric conversion unit in plan view, and the first base and said. The thermoelectric conversion unit is provided between the second base portion so as to surround the thermoelectric conversion unit and the holding portion for holding the gas layer or the vacuum, and the area of the thermoelectric conversion unit is the area of the thermoelectric conversion unit in a plan view. The thermoelectric conversion device is characterized in that the area of the region where the first base portion and the second base portion face each other via the thermoelectric conversion unit and the thermal insulator is 1/100 or less .

In the above configuration, a plurality of the thermoelectric conversion units separated from each other via the thermal insulator may be provided between the first base portion and the second base portion.

In the above configuration, the first thermoelectric material and the second thermoelectric material are alternately provided in the first direction parallel to the surface of the first base portion and the second base portion, and the first connection layer and the second connection are provided. The layers are electrically and thermally connected between the first thermoelectric material and the second thermoelectric material with the first thermoelectric material and the second thermoelectric material, and are provided alternately in the first direction. The thermoelectric conversion unit is configured to include a first heat conductive layer and a second heat conductive layer that are thermally connected to the first connection layer and the second connection layer, respectively, and extend in a second direction intersecting the surface. be able to. In the above configuration, the first thermoelectric material and the second thermoelectric material are arranged in the plane direction of the first base portion and the second base portion, and the first connection layer and the second connection layer are arranged in the plane direction. The first thermoelectric material and the second thermoelectric material may be alternately thermally and electrically connected in the intersecting direction . In the above configuration, the first base may be thermally connected to the surface of a living body of a homeothermic animal, and the second base may be thermally connected to air.

According to the present invention, it is possible to provide a thermoelectric conversion device and an electronic device that are small in size and have high output.

FIG. 1 is a schematic diagram showing a Zeebeck element. 2 (a) and 2 (b) are a plan view and a cross-sectional view of the thermoelectric conversion device according to Comparative Example 1, respectively. 3A and 3B are a plan view and a cross-sectional view of the thermoelectric conversion device according to Comparative Example 2, respectively. 4 (a) and 4 (b) are a plan view and a cross-sectional view of the thermoelectric conversion device according to the first embodiment, respectively. 5 (a) to 5 (c) are diagrams showing the simulation results of m ₀ , γ d, and P _OUT for γ in Comparative Example 1, respectively. 6 (a) and 6 (b) are diagrams showing the simulation results of P _OUT , m ₀ , γ d, (1-γ) d and t _Cu with respect to t ₀ in Comparative Example 1. FIG. 7 is a diagram showing simulation results of _{P OUT} , m ₀ , γ d, (1-γ) d and t _Cu with respect to VS in Comparative Example 1. 8 (a) to 8 (c) are diagrams showing the simulation results of m ₀ , γ d, and P _OUT for γ in Example 1, respectively. FIG. 9 is a diagram showing simulation results of P _OUT , m ₀ , γd, (1-γ) d and t _Cu with respect to t ₀ in Example 1. FIG. 10 is a diagram showing P _OUT , m ₀ , _γd , (1-γ) d and t _Cu simulation results for VS in Example 1. 11 (a) and 11 (b) are cross-sectional views of the thermoelectric conversion device according to the first modification of the first embodiment. FIG. 12 is a plan view of the thermoelectric conversion device according to the second modification of the first embodiment. 13 (a) and 13 (b) are a cross-sectional view and a plan view of the thermoelectric conversion device according to the third modification of the first embodiment. 14 (a) and 14 (b) are cross-sectional views of the thermoelectric conversion device according to the modified example 4 of the first embodiment, and FIG. 14 (c) is the thermoelectric conversion device according to the modified example 5 of the first embodiment. It is a cross-sectional view of. 15 (a) and 15 (b) are cross-sectional views of an electronic device using the thermoelectric conversion device according to the sixth modification of the first embodiment. FIG. 16 is a cross-sectional view of the electronic device according to the second embodiment. FIG. 17 is a block diagram of the electronic device according to the first modification of the second embodiment. FIG. 18 is a block diagram of the electric power system according to the first modification of the second embodiment. 19 (a) and 19 (b) are diagrams showing a simulation model. 20 (a) and 20 (b) are diagrams showing simulation results of γd, (1-γ) d, ΔT, _βΔT , VS and P _OUT for γ and m ₀ , respectively, in Example 1. FIG. 21 is a diagram showing simulation results of γd, (1-γ) d, ΔT, _βΔT , VS and P _OUT with respect to t ₀ in Example 1. FIG. 22 is a diagram showing simulation results of γd, (1-γ) d, ΔT, _βΔT , VS and P _OUT with respect to t ₀ in Comparative Example 1. 23 (a) and 23 (b) are schematic cross-sectional views of the thermoelectric conversion device according to Comparative Example 1 and Example 1, respectively. FIG. 24 is a diagram showing a current I and an output power P _OUT with respect to the output voltage V _out in the first embodiment. FIG. 25 is a diagram showing simulation results of γd, (1-γ) d, ΔT, _βΔT , VS and P _OUT with respect to the minimum dimension in Comparative Example 1. 26 (a) is a plan view of the thermoelectric conversion device according to the fourth embodiment, and FIG. 26 (b) is a sectional view taken along the line AA of FIG. 26 (a). FIG. 27 is a diagram showing simulation results of γd, (1-γ) d, ΔT, _βΔT , VS and P _OUT with respect to D in Example 4. 28 (a) is a plan view of the thermoelectric conversion device according to the first modification of the fourth embodiment, and FIG. 28 (b) is a sectional view taken along the line AA of FIG. 28 (a). FIG. 29 (a) is a diagram showing the simulation results of t _Cu , _γd , m ₀ , VS and P _OUT with respect to L in the modified example 1 of Example 4, and FIG. 29 (b) is a diagram showing L, γd with respect to t _Cu . , M ₀ , VS and _{P OUT} simulation results. FIG. 30 is a diagram showing simulation results of L, _γd , m ₀ , VS and P _OUT with respect to t _Cu when the thermal insulator is in a vacuum. FIG. 31 is a cross-sectional view of the thermoelectric conversion device according to the second modification of the fourth embodiment. 32 (a) is a plan view of the thermoelectric conversion device according to the third modification of the fourth embodiment, and FIG. 32 (b) is a sectional view taken along the line AA of FIG. 32 (a). 33 (a) is a plan view of the thermoelectric conversion device according to the modified example 4 of the fourth embodiment, and FIG. 33 (b) is a sectional view taken along the line AA of FIG. 33 (a).

FIG. 1 is a schematic diagram showing a Zeebeck element. As shown in FIG. 1, the Seebeck element 10 includes thermoelectric materials 32a, 32b, electrodes 24a, 24b and a connecting layer 34a. The thermoelectric materials 32a and 32b are, for example, n-type and p-type, respectively. One ends of the thermoelectric materials 32a and 32b are connected via a connecting layer 34a. The other ends of the thermoelectric materials 32a and 32b are connected to the electrodes 24a and 24b, respectively. When heat is absorbed into the connection layer 34a as shown by the arrow 36a and heat is dissipated from the electrodes 24a and 24b as shown by the arrow 36b, an electromotive force is generated between the electrodes 24a and 24b due to the Seebeck effect. When the load 40 is connected between the electrodes 24a and 24b, a current 42 flows. By connecting a plurality of such Zeebeck elements 10 in series, the electromotive force can be increased.

The thermoelectric conversion device (or thermoelectric power generation device) is manufactured by joining a large number of pellets of an n-type thermoelectric material and a p-type thermoelectric material cut by machining, for example. Further, the thermoelectric conversion device can also be manufactured by laminating a substrate formed of a large number of p-type thermoelectric materials in the form of pellets on a substrate formed of a large number of pellets of the n-type thermoelectric material. With these manufacturing methods, it is difficult to increase the degree of integration of the Seebeck elements, and the degree of integration of the Seebeck elements is, for example, about several hundred.

Since the electromotive force per Zeebeck element is small, it is preferable to connect a plurality of Zeebeck elements in series. However, if the degree of integration of the Seebeck elements is small, the number of Seebeck elements connected in series is limited. Therefore, in order to increase the output power of the thermoelectric conversion device, the thermoelectric conversion device is designed with priority given to the electromotive force per Zeebeck element. In such a design that prioritizes the electromotive force per unit, the structure is generally not optimized for the output power.

Therefore, it is conceivable to manufacture a thermoelectric conversion device by applying microfabrication technology and thin film forming technology based on photolithography technology used for manufacturing semiconductor integrated circuits and the like. In such a method, it is possible to design a thermoelectric conversion device having desired output characteristics from the number of integrated Zeebeck elements and a large degree of freedom in the element shape and dimensions. As a result, there is a possibility that a thermoelectric conversion device in which Zebeck elements having an optimized structure are integrated at high density and on a large scale can be realized.

[Comparative Example 1]
The structure of a thermoelectric conversion device that uses a thin film as a thermoelectric material was investigated. Comparative Example 1 is an example in which a π-type Zeebeck element is used. 2 (a) and 2 (b) are a plan view and a cross-sectional view of the thermoelectric conversion device according to Comparative Example 1, respectively. FIG. 2A illustrates a thermoelectric thin film, a connecting layer and electrodes. FIG. 2B is a cross-sectional view taken along the line AA of FIG. 2A. The arrangement directions of the thermoelectric thin films 12a and 12b are the X direction and the Y direction, and the laminating method of each layer is the Z direction.

As shown in FIGS. 2A and 2B, the thermoelectric thin films 12a and the thermoelectric thin films 12b are alternately arranged in the X direction in the thermoelectric conversion device 110. The thermoelectric thin films 12a and 12b are, for example, n-type and p-type, respectively. The adjacent thermoelectric thin films 12a and 12b are electrically and thermally connected to the connecting layers 14a and 14b in the −Z direction and the + Z direction, respectively. A pair of thermoelectric thin films 12a and 12b form one Zeebeck element 10. The plurality of Seebeck elements 10 are connected in series between the electrodes 24a and 24b. The connection layer 14a is thermally connected to the high temperature base 22a via the electric insulating film 20 in the −Z direction. The connection layer 14b is thermally connected to the low temperature base 22b via the electric insulating film 20 in the + Z direction. An electrical and thermal insulating layer 18 is provided between the thermoelectric thin films 12a and 12b.

The dimensions of the bases 22a and 22b in the X and Y directions are D, the length of one side of the square 26 containing one thermoelectric thin film 12a or 12b is d, and the dimension of one side of the thermoelectric thin film 12a or 12b in the square 26. Is the element size γd. Of the voltage differences between the electrodes 24a and _24b , the electromotive force VS by the Seebeck element 10, the temperature difference between the surfaces of the bases 22a and 22b is ΔT, the film thicknesses of the thermoelectric thin films 12a and 12b are t ₀ , the connection layer 14a and The film thickness of 14b is t _Cu , the film thickness of the insulating film 20 is t _Al2O3 , and the film thickness of the bases 22a and 22b is t _HS .

In Comparative Example 1, heat conduction occurs in the Z direction. Therefore, when the film thickness t ₀ of the thermoelectric thin films 12a and 12b becomes small (for example, 100 nm), the thermal resistance becomes small, and the temperature difference _ΔTG (not shown) in the Z direction of the thermoelectric thin films 12a and 12b becomes small. Therefore, the electromotive force is reduced. If sufficient thermal resistance is to be obtained, the dimensions of the thermoelectric thin films 12a and 12b in the X and Y directions will be about the film thickness t ₀ , and the processing process is not easy and unrealistic.

[Comparative Example 2]
Comparative Example 2 is an example in which an in-plane type Zeebeck element is used. 3A and 3B are a plan view and a cross-sectional view of the thermoelectric conversion device according to Comparative Example 2, respectively. FIG. 3 (a) illustrates the thermoelectric thin film, the connecting layer and the base. FIG. 3B is a sectional view taken along the line AA of FIG. 3A. The arrangement direction and stretching direction of the thermoelectric thin films 12a and 12b are set to the X direction and the Y direction, respectively, and the laminating method of each layer is set to the Z direction.

As shown in FIGS. 3A and 3B, in the thermoelectric conversion device 112, the thermoelectric thin films 12a and the thermoelectric thin films 12b are alternately arranged in the X direction and stretched in the Y direction. The thermoelectric thin films 12a and 12b are, for example, n-type and p-type, respectively. The adjacent thermoelectric thin films 12a and 12b are electrically and thermally connected to the connecting layers 14a and 14b in the −Y direction and the + Y direction, respectively. A pair of thermoelectric thin films 12a and 12b form one Zeebeck element 10. The plurality of Seebeck elements 10 are connected in series between the electrodes 24a and 24b. The connection layer 14a is thermally connected to the high temperature base 22a in the −Y direction. The connection layer 14b is thermally connected to the low temperature base 22b in the + Y direction. An insulating layer 18 is provided between the thermoelectric thin films 12a and 12b.

In Comparative Example 2, the length L in the Y direction in which heat conduction occurs in the thermoelectric thin films 12a and 12b can be increased. As a result, the temperature difference _ΔTG (not shown) in the Y direction between the thermoelectric thin films 12a and 12b can be increased. However, as the length L increases, the electrical resistance of the thermoelectric thin films 12a and 12b increases. As a result, even if the electromotive force _VS can be increased, the output power cannot be increased.

As described above, in Comparative Example 1 of the π type using the thermoelectric thin films 12a and 12b, the thermal resistance becomes too small, and in Comparative Example 2 of the inplane type, the electric resistance becomes too large. As described above, in Comparative Examples 1 and 2, the structure is not suitable for optimizing the thermal resistance and the electric resistance, which are in a trade-off relationship, to realize high output power.

4 (a) and 4 (b) are a plan view and a cross-sectional view of the thermoelectric conversion device according to the first embodiment, respectively. FIG. 4A illustrates a thermoelectric thin film, a connecting layer and electrodes. 4 (b) is a sectional view taken along the line AA of FIG. 4 (a). The surfaces of the thermoelectric thin films 12a and 12b are XY planes, the arrangement direction (width direction) and stretching direction (length direction) of the thermoelectric thin films 12a and 12b are the X direction and the Y direction, respectively, and the laminating method of each layer is the Z direction. ..

As shown in FIGS. 4A and 4B, in the thermoelectric conversion device 100, the thermoelectric thin film 12a and the thermoelectric thin film 12b are strip-shaped in a plan view. The thermoelectric thin films 12a and 12b are arranged alternately in the X direction and are stretched in the Y direction. The thermoelectric thin films 12a and 12b are, for example, n-type and p-type, respectively. The adjacent thermoelectric thin films 12a and 12b are electrically and thermally connected to the connecting layers 14a and 14b alternately in the X direction. The connecting layers 14a and 14b extend in the Y direction. A pair of thermoelectric thin films 12a and 12b form one Zeebeck element 10. The plurality of Seebeck elements 10 are connected in series between the electrodes 24a and 24b. The connecting layers 14a and 14b are thermally connected to the heat conductive layers 16a and 16b in the −Z direction and the + Z direction, respectively. The heat conductive layers 16a and 16b are thermally connected to the high temperature base 22a and the low temperature base 22b, respectively, via the electric insulating film 20. Insulating layers 18a and 18b are provided between the heat conductive layers 16a and 16b.

The X-direction and Y-direction dimensions of the thermoelectric conversion device 100 are D, the pitch of the thermoelectric thin films 12a and 12b in the X direction is d, and the dimension of one thermoelectric thin film 12a or 12b is the element dimension γd. Of the voltage difference between the electrodes 24a and _24b , the electromotive force VS by the Seebeck element 10 and the temperature difference between the surfaces of the bases 22a and 22b are defined as ΔT. The film thicknesses of the thermoelectric thin films 12a and 12b and the connecting layers 14a and 14b are t ₀ , the film thicknesses of the heat conductive layers 16a and 16b are t _Cu , the film thickness of the insulating film 20 is t _Al2O3 , and the film thicknesses of the bases 22a and 22b are t. Let it be _HS .

In such a structure, the directions of the heat flow and the current of the thermoelectric thin films 12a and 12b are in the X direction. In Comparative Example 1, the thermal resistance decreased when the film thickness t ₀ of the thermoelectric thin films 12a and 12b became small, but in Example 1, the thermal resistance increased as the film thickness t ₀ decreased. In Comparative Example 2, the electric resistance of the thermoelectric thin films 12a and 12b increased as the length L in the Y direction increased, but in Example 1, the electric resistance decreased as the length L increased. By making the length L sufficiently larger than the film thickness t ₀ in this way, the thermal resistance is not too small and the electrical resistance is not too large, and the element size γd (or γ) in the X direction is used for the trade-off. The desired output power can be obtained by optimizing the related thermal resistance and electrical resistance.

For applications where the operating temperature is near room temperature or up to about several hundred degrees Celsius, the thermoelectric materials used for the thermoelectric thin films 12a and 12b can be bismuth tellurium alloys, full-Whisler alloys, or half-Whisler alloys. The bismuth tellurium-based alloys are, for example, Bi ₂ Te _3-x Se _x as an n-type and, for example, Bi _2-x Sb _x Te ₃ as a p-type. Full-Whisler alloys are n-type, for example Fe ₂ VAL _1-x Ge _x , Fe ₂ VAL _1-x Si _x or Fe ₂ VTa _x Al _1-x , and p-type, for example Fe ₂ V _1-x W _x . Al, Fe ₂ V _1-x Ti _x Al or Fe ₂ V _1-x Ti _x Ga, and other materials based on, for example, Fe ₂ NbGa, Fe ₂ HfSi, Fe ₂ TaIn, Fe ₂ TiSn or Fe ₂ ZrGe. .. Half-Whisler alloys include, for example, TiptSn, (Hf _1-x Zr _x ) NiSn or NbCoSn as n-type, and TiCoSn _x Sb _1-x , Zr (Ni _1-x Co _x ) Sn, Zr (Ni) as p-type. _1-x In _x ) Sn, HfPtSn. By using the n-type thermoelectric material and the p-type thermoelectric material as similar materials, the thermoelectric thin films 12a and 12b can be easily manufactured. Further, when the temperature range to be used is sufficiently higher than room temperature, Si or SiGe alloy can also be used as the thermoelectric material used for the thermoelectric thin films 12a and 12b.

As the connecting layers 14a and 14b, materials having high electric conductivity and thermal conductivity are preferable, and for example, a metal layer such as Cu, Al, Au or Ag can be used. The connecting layers 14a and 14b may be made of different materials.

As the heat conductive layers 16a and 16b, materials having a large thermal conductivity are preferable, and for example, a metal layer such as Cu, Al, Au or Ag can be used. The heat conductive layers 16a and 16b may be insulator layers as long as they have a high thermal conductivity. The heat conductive layers 16a and 16b may be made of different materials. The connecting layers 14a and 14b and the heat conductive layers 16a and 16b may be made of different materials.

As the insulating layers 18a and 18b (insulators), materials having high insulating properties and sufficiently smaller thermal conductivity than the thermal conductive layers 16a and 16b are preferable. Examples of the insulating layers 18a and 18b include an inorganic insulator such as silicon oxide or a porous material thereof, an alkyl group-containing silica or a similar oxide and insulator, and a resin (for example, acrylic resin, epoxy resin, vinyl chloride resin, silicone). Insulators such as resin, fluororesin, phenol resin, bakelite resin, polyethylene resin, polycarbonate resin, polystyrene resin, polyproprene resin) or rubber (natural rubber, ethylene propylene rubber, chloroprene rubber, silicon rubber, butyl rubber or polyurethane rubber), Insulating gas such as nitrogen or air, vacuum or the like can be used. The insulating layers 18a and 18b can be formed by using a CVD (Chemical Vapor Deposition) method, a sputtering method or a spin coating method.

As the insulating film 20, a material having high insulating properties and high thermal conductivity is preferable, and an inorganic insulator such as aluminum oxide can be used. The insulating film 20 may not be provided, but it is preferable to provide the insulating film 20 for insulation when the heat conductive layers 16a and 16b and the bases 22a and 22b are conductors.

As the bases 22a and 22b, materials having a large thermal conductivity are preferable, and for example, metals such as Cu, Al, Au or Ag, ceramics such as Si or alumina and the like can be used. The insulating film 20 may be formed on the bases 22a and 22b by sputtering or a CVD method. When the bases 22a and 22b are electrical insulators, the insulating film 20 may not be used. At least one of the bases 22a and 22b can be formed by using a sputtering method or a CVD method. As a result, the bases 22a and 22b can be thinned. At least one of the bases 22a and 22b can be formed by plating. As a result, the bases 22a and 22b can be made into a thick film to some extent. When at least one of the bases 22a and 22b is an oxide film or ceramics, a coating film by spin coating or the like can be used. As the bases 22a and 22b, a structure (for example, a fin structure or a heat sink structure) and a material having high heat exchange characteristics and heat dissipation characteristics (for example, a heat dissipation sheet, a heat dissipation material containing a volatile material or an endothermic material, or an alumite-processed surface Al, etc. ) Can be used.

For Comparative Example 1 and Example 1, a simulation was performed to optimize the thermal resistance and the electric resistance having a trade-off relationship. A trade-off parameter γ indicating the proportion of the thermoelectric thin films 12a and 12b to the area of the bases 22a and 22b was used. The simulation was performed assuming a lumped constant circuit using the thermal conductivity, electrical conductivity and Seebeck coefficient of each material. In the simulation, the dimensions D × D of the bases 22a and 22b, the temperature difference ΔT between the bases 22a and 22b, the electromotive force VS by the _Zeebeck element, the film thickness t ₀ of the thermoelectric thin films 12a and 12b, and the trade-off parameter γ are set. And other dimensions were calculated.

The simulation conditions are shown below.
Thermoelectric thin film 12a: n-type Fe ₂ VAL _1-x Ta _x
Thermoelectric thin film 12b: p-type Fe ₂ V _1-x Ti _x Ga
Dimensionless figure of merit: 0.09
Connection layers 14a, 14b: Cu
Thermally conductive layers 16a, 16b: Cu
Insulation layer 18: SiO ₂
Insulating film 20: Al _{2O 3} , film thickness t _Al 2O3: 100 nm
Bases 22a, 22b: Cu, film thickness t _HS : 1 mm
D x D: 10 mm x 10 mm
ΔT: 1K

[Simulation of Comparative Example 1]
The simulation was performed with t ₀ = 100 nm and _VS = 1 V. 5 (a) to 5 (c) are diagrams showing simulation results of the element logarithm m ₀ , the element size γ d, and the output power P _OUT with respect to γ in Comparative Example 1, respectively. The element logarithm m ₀ of the Zeebeck element is a pair of thermoelectric thin films 12a and 12b. The element size γd is the width of each thermoelectric thin film 12a and 12b in the X direction. The output power P _OUT is the maximum output power of the thermoelectric conversion device obtained by adjusting the load resistance. In the simulation here, the temperature difference ΔT is optimized so that it always has 1K. In the actual design, the optimization will be performed in consideration of the amount of heat input.

As shown in FIG. 5A, the element logarithm m ₀ increases as γ increases. This is because as the trade-off parameter γ increases, the thermal resistance between the bases 22a and 22b decreases. Therefore, the electromotive force per Zeebeck element 10 becomes small, and the number of series connections of the _Zeebeck element 10 increases in order to secure the electromotive force VS.

As shown in FIG. 5 (b), as γ becomes larger, γd becomes larger. γ ² is the area ratio of the thermoelectric thin films 12a and 12b in D × D. γd is the dimensional ratio of the thermoelectric thin films 12a and 12b to d.

As shown in FIG. 5C, the output power P _OUT is about 11 μW and peaks when γ is about 0.12. From FIGS. 5 (a) and 5 (b), the element logarithm m ₀ and the element dimension γ d at which the output power P _OUT peaks can be obtained.

Next, the film thicknesses t ₀ of the thermoelectric thin films 12a and 12b were changed from 10 nm to 10000 nm, and the element logarithm m ₀ and the element size γ d at which the output power P _OUT was maximized were calculated. With ΔT = 1K, simulations were performed when the electromotive force _VS was 1 V and when the electromotive force was 100 mV.

6 (a) and 6 (b) are diagrams showing the simulation results of P _OUT , m ₀ , γ d, (1-γ) d and t _Cu with respect to t ₀ in Comparative Example 1. 6 (a) and 6 (b) show _VS = 1 V and _VS = 100 mV, respectively. P _OUT indicates the maximum value of output power. In addition, in FIG. 6A and FIG. 6B, the output power is shown as P _out . The same applies to the following figure.

As shown in FIGS. 6 (a) and 6 (b), the output power P _OUT becomes smaller as the film thickness t ₀ becomes thinner. The film thickness to which a microfabrication technique such as a normal dry etching method and a thin film forming technique such as a sputtering method or a CVD method can be applied is about 1000 nm or less, preferably about 100 nm. In this range, the output power P _OUT becomes very small.

FIG. 7 is a diagram showing simulation results of _{P OUT} , m ₀ , γ d, (1-γ) d and t _Cu with respect to VS in Comparative Example 1. The film thickness t ₀ is set to 100 nm. As shown in FIG. 7, when VS becomes small, _{P OUT} becomes small.

[Simulation of Example 1]
The simulation was performed with t ₀ = 100 nm and _VS = 100 mV. The simulation conditions are the same as in Comparative Example 1. The width of the heat conductive layers 16a and 16b in the X direction was the same as the width of the connecting layers 14a and 14b in the X direction. 8 (a) to 8 (c) are diagrams showing the simulation results of m ₀ , γ d, and P _OUT for γ in Example 1, respectively. As shown in FIGS. 8 (a) and 8 (b), there is no solution when γ <0.5. When 0.5 <γ, two solutions are obtained. A solution having a large electromotive force per Zeebeck element and a small number of elements (solid line) and a solution having a small electromotive force per Zeebeck element and a large number of elements (dotted line). As shown in FIG. 8 (c), the output power P _OUT is the same for both solutions, and is maximum at γ = 0.5. From the viewpoint of ease of manufacturing the element, a solution (solid line) with a small number of elements was adopted.

Next, when the electromotive force _VS is 100 mV, the film thickness t ₀ of the thermoelectric thin films 12a and 12 b is changed from 10 nm to 200 nm, and the element pair number m ₀ and the element dimension _γd and (1- γ) d was calculated.

FIG. 9 is a diagram showing simulation results of P _OUT , m ₀ , γd, (1-γ) d and t _Cu with respect to t ₀ in Example 1. As shown in FIG. 9, the output power P _OUT is 250 μW or more even when the film thickness t ₀ is 200 nm or less. P _OUT hardly depends on the film thickness t ₀ . 250 μW can be realized as P _OUT at t ₀ = 100 nm, which is suitable for microfabrication technology and thin film formation technology.

FIG. 10 is a diagram showing simulation results of _{P OUT} , m ₀ , γ d, (1-γ) d and t _Cu with respect to VS in Example 1. The film thickness t ₀ is set to 100 nm. As shown in FIG. 10, _{P OUT} is large even if VS is small. Even if VS is 100 mV or less, 250 μW can be realized as _{P OUT} .

As the thermoelectric material used for the thermoelectric thin films 12a and 12b, a BiTe-based material having a larger Seebeck coefficient is used. Further, the insulating layers 18a and 18b are made of a material having a thermal conductivity smaller than that of SiO ₂ such as resin. Further, by thinning the bases 22a and 22b, the output power P _OUT can be further improved.

According to the first embodiment, the thermoelectric thin film 12a (first thermoelectric thin film) and the thermoelectric thin film 12b (second thermoelectric thin film) are alternately provided in the X direction (the first direction parallel to the surfaces of the thermoelectric thin films 12a and 12b). There is. The thermoelectric thin films 12a and 12b have opposite conductive types. The connection layers 14a (first connection layer) and 14b (second connection layer) are electrically and thermally connected to the thermoelectric thin films 12a and 12b between the thermoelectric thin films 12a and 12b, and are provided alternately in the X direction. ing. The heat conductive layers 16a and 16b are thermally connected to the connecting layers 14a and 14b, respectively, and extend in the Z direction (second direction intersecting the XY plane). As a result, the output power P _OUT can be increased even if a thin film of thermoelectric material is used.

Further, the heat conductive layers 16a and 16b are provided on opposite sides to the surfaces of the thermoelectric thin films 12a and 12b. That is, the heat conductive layer 16a is thermally connected to the connecting layer 14a and extends in the −Z direction (second direction intersecting the XY plane). The heat conductive layer 16b is thermally connected to the connecting layer 14b and extends in the + Z direction (direction opposite to the second direction). As a result, a temperature difference in the X direction between the thermoelectric thin films 12a and 12b is generated, and power can be generated. For example, by forming the bases 22a and 22b into a comb shape, the heat conductive layers 16a and 16b may be provided on the same side with respect to the surfaces of the thermoelectric thin films 12a and 12b.

The film thickness t ₀ of the thermoelectric thin films 12a and 12b is preferably 10 μm or less, more preferably 5 μm or less. The film thickness t ₀ of the thermoelectric thin films 12a and 12b that can be formed by using the technique for manufacturing a semiconductor integrated circuit that can increase the degree of freedom in shape and dimensions is 1 μm or less. Even if the film thickness t ₀ is 1 μm or less, the output power P _OUT can be increased in Example 1 as compared with Comparative Example 1. In the simulation results of Example 1 and Comparative Example 1, the film thickness t ₀ is preferably 500 nm or less, more preferably 200 nm or less.

The insulating layers 18a and 18b (insulators) have a lower thermal conductivity than the heat conductive layers 16a and 16b through which the heat conductive layers 16a and 16b penetrate. When the heat conductive layers 16a and 16b are provided on the + Z side and the −Z side, the insulating layers 18a (first insulator) and 18b (second insulator) are provided on the −Z direction side and the −Z direction side of the thermoelectric thin films 12a and 12b. The heat conductive layers 16a and 16b penetrate in the + Z direction side, respectively, and the heat conductivity is smaller than that of the heat conductive layers 16a and 16b. As described above, by using the insulating layers 18a and 18b, the thermal resistance of the portions other than the heat conductive layers 16a and 16b between the bases 22a and 22b can be increased.

The thermoelectric thin films 12a and 12b are stretched in the Y direction (a third direction parallel to the surface and intersecting the first direction). As a result, the electrical resistance of the thermoelectric thin films 12a and 12b in the X direction can be reduced. The length of the thermoelectric thin films 12a and 12b in the Y direction is preferably 10 times or more, more preferably 100 times or more, and further preferably 1000 times or more the film thickness _t0 .

The γd (width in the X direction) of the thermoelectric thin films 12a and 12b is larger than the film thickness _t0 of the thermoelectric thin films 12a and 12b. As a result, the thermal resistance of the thermoelectric thin films 12a and 12b in the X direction can be increased. The element size γd is preferably 2 times or more the film thickness t ₀ , and more preferably 10 times or more.

[Modification 1 of Example 1]
11 (a) and 11 (b) are cross-sectional views of the thermoelectric conversion device according to the first modification of the first embodiment. As shown in FIG. 11A, the width of the heat conductive layers 16a and 16b in the X direction may be larger than the width of the connecting layers 14a and 14b in the X direction. As shown in FIG. 11B, the width of the heat conductive layers 16a and 16b in the X direction may be smaller than that of the connecting layers 14a and 14b. Other configurations are the same as those in the first embodiment, and the description thereof will be omitted.

[Modification 2 of Example 1]
FIG. 12 is a plan view of the thermoelectric conversion device according to the second modification of the first embodiment. As shown in FIG. 12, a plurality of modules 30 are provided in the Y direction. Each module 30 includes a Seebeck element 10 arranged in the X direction between the electrodes 24a and 24b. Each module 30 is electrically and thermally separated by an insulating layer 18. Depending on the application, each module 30 can be connected in series, connected in parallel, or electrically connected in combination of series and parallel. By integrating the wiring connecting the modules 30 on the board, the internal resistance of the wiring can be reduced. Other configurations are the same as those in the first embodiment, and the description thereof will be omitted.

[Modification 3 of Example 1]
13 (a) and 13 (b) are a cross-sectional view and a plan view of the thermoelectric conversion device according to the third modification of the first embodiment. As shown in FIG. 13A, a groove 28a is formed in the base portion 22a and the insulating layer 18a, and a groove 28b is formed in the base portion 22b and the insulating layer 18b. The insulating layers 18a and 18b are solid. The inside of the grooves 28a and 28b is a gas such as air or a vacuum, and has a higher thermal conductivity than the insulating layers 18a and 18b. Therefore, even if the temperature difference between the bases 22a and 22b is the same, the temperature difference between the thermoelectric thin films 12a and 12b can be increased. As shown in FIG. 13B, a plurality of grooves 28b are provided in the base portion 22b. Similarly, the base portion 22a is also provided with a plurality of grooves 28a. The grooves 28b are arranged in the X direction and the Y direction. By dividing the groove 28b into short pieces, the strength of the thermoelectric conversion device can be increased. The groove 28b may be provided so as to extend in the Y direction. Other configurations are the same as those in the first embodiment, and the description thereof will be omitted.

According to the third modification of the first embodiment, the base portion 22a and the insulating layer 18a have a groove 28a (first groove) between the heat conductive layers 16a. The base 22b and the insulating layer 18b have a groove 28b (second groove) between the heat conductive layers 16a. As a result, the temperature difference between the thermoelectric thin films 12a and 12b can be increased. The insulating layers 18a and 18b may be completely removed to form the grooves 28a and 28b.

[Modified Example 4 of Example 1]
FIG. 14A is a cross-sectional view of the thermoelectric conversion device according to the modified example 4 of the first embodiment. As shown in FIG. 14A, the positions of the thermoelectric thin films 12a and 12b in the Z direction are not the same. Other configurations are the same as those in the first embodiment, and the description thereof will be omitted. Depending on the method of manufacturing the thermoelectric thin films 12a and 12b, the thermoelectric thin films 12a and 12b may not be located on the same XY plane.

FIG. 14B is another example of the modification 4 of the first embodiment. As shown in FIG. 14B, the connection layers 14a and 14b may be in contact with the thermoelectric thin film 12a in the + Z direction and may be in contact with the thermoelectric thin film 12b in the −Z direction. The heat conductive layer 16a may be thermally connected to the connecting layers 14a and 14b via the thermoelectric thin film 12b, and the heat conductive layer 16b may be thermally connected to the connecting layers 14a and 14b via the thermoelectric thin film 12a. The width of the heat conductive layers 16a and 16b in the X direction may be larger than the width of the connecting layers 14a and 14b in the X direction. The width of the heat conductive layers 16a and 16b in the X direction may be smaller than that of the connecting layers 14a and 14b. In FIG. 14B, since the thermoelectric thin films 12b, the connecting layers 14a and 14b, and the thermoelectric thin films 12a are laminated in the Z direction, the thermoelectric thin films 12a and 12b can easily come into contact with the connecting layers 14a and 14b.

[Modification 5 of Example 1]
FIG. 14 (c) is a cross-sectional view of the thermoelectric conversion device according to the modified example 5 of the first embodiment. As shown in FIG. 14 (c), a plurality of layers 48 are laminated between the base portions 22a and 22b via the insulating film 20. Each layer 48 includes the thermoelectric thin films 12a and 12b of the modified example 4 of the first embodiment, the connecting layers 14a and 14b, the heat conductive layers 16a and 16b, and the insulating layers 18a and 18b. The insulating film 20 is an electrical insulator and has a high thermal conductivity. Other configurations are the same as those in the first embodiment, and the description thereof will be omitted.

According to the modification 5 of the first embodiment, the heat conductive layer 16a contained in one of the adjacent layers among the plurality of layers 48 and the heat conductive layer 16b contained in the other of the adjacent layers 48 are electrically formed. It is thermally connected via the insulating film 20. By forming the thermoelectric material into a thin film in this way, a plurality of layers 48 can be thermally connected in series between the bases 22a and 22b. This makes it possible to efficiently convert heat into electric power. The Seebeck elements of Example 1 and its modifications 1 to 3 may be laminated as in the modification 5 of Example 1.

The thermoelectric conversion device according to the first embodiment and its modifications can be used as a power source for a wearable device, a microcontroller or a sensor. For example, a thermoelectric conversion device is worn on the body. As a result, the thermoelectric conversion device can generate electric power by using the heat radiated from the body and supply the generated electric power to the wearable device or the sensor. Further, the thermoelectric conversion device can be used for power generation by waste heat from a car engine (heat from exhaust gas) or the like.

[Modified Example 6 of Example 1]
Modification 6 of Example 1 is an example in which the thermoelectric conversion device according to Example 1 and the modification thereof is used as a Pelche element. 15 (a) and 15 (b) are cross-sectional views of an electronic device using the thermoelectric conversion device according to the sixth modification of the first embodiment. As shown in FIG. 15A, the integrated circuit element 52 is mounted on a substrate 58 such as a printed circuit board. The integrated circuit element 52 is, for example, a microprocessor or a SoC (System on a Chip). A heat conduction member 56, a thermoelectric conversion device 51, a heat conduction member 56, and a heat dissipation member 54 are provided on the integrated circuit element 52. The thermoelectric conversion device 51 uses the thermoelectric conversion device according to the first embodiment and its modifications as a Pelche element. The heat conductive member 56 is a metal layer that makes thermal contact, such as copper or indium. The heat radiating member 54 is, for example, a heat radiating fin. The materials exemplified in Example 2 may be used for the heat conductive member 56 and the heat radiating member 54. As shown in FIG. 15B, the thermoelectric conversion device 51 may be mounted directly on the integrated circuit element 52.

As in the modification 6 of the first embodiment, the integrated circuit element 52 can be cooled by applying electric power to the thermoelectric conversion device 51 which is a Pelche element. As shown in FIG. 15A, the thermoelectric conversion device 51 may be mounted between the integrated circuit element 52 and the heat radiating member 54 via the heat conductive member 56. As shown in FIG. 15B, the thermoelectric conversion device 51 may be directly integrated on the integrated circuit element 52 by using a semiconductor process. In this case, it is also possible to integrate the thermoelectric conversion device 51 directly above the portion on the integrated circuit element 52 where the heat rise is particularly high. By forcibly cooling the integrated circuit element 52 by these, the problem of heat dissipation in the integrated circuit element 52 can be solved.

The second embodiment is an example of an electronic device having a thermoelectric conversion device. FIG. 16 is a cross-sectional view of the electronic device according to the second embodiment. As shown in FIG. 16, in the electronic device 105, the power generation device 50 is provided between the integrated circuit element 52 and the heat dissipation member 54. The integrated circuit element 52 is mounted on the substrate 58. The power generation device 50 and the integrated circuit element 52 are thermally connected via a heat conductive member 56.

The power generation device 50 includes, for example, a thermoelectric conversion device according to Comparative Example 1, Comparative Example 2, Example 1, and a modification thereof. One of the connecting layers 14a and 14b of the thermoelectric conversion device is thermally connected to the heat conductive member 56 via one of the bases 22a and 22b. The other of the connecting layers 14a and 14b is thermally connected to the heat radiating member 54 via the other of the bases 22a and 22b.

The integrated circuit element 52 is a package on which an integrated circuit such as a SoC (System on a Chip) is formed or an integrated circuit chip is mounted. The integrated circuit element 52 may be a microprocessor or the like. The substrate 58 is, for example, a printed circuit board. The heat conductive member 56 is preferably made of a material having a high thermal conductivity, and for example, a metal such as Cu, Al, Au or Ag, ceramics or a highly heat conductive silicone resin can be used. The bases 22a and 22b of the thermoelectric conversion device may be brought into direct contact with the integrated circuit element 52 without providing the heat conductive member 56. The heat radiating member 54 is, for example, a housing of an electronic device, a heat radiating plate subjected to alumite processing, a heat radiating fin, or a heat radiating fan. The power generation device 50 may be a π-type thermoelectric conversion device or other thermoelectric conversion device.

According to the second embodiment, when the integrated circuit element 52 operates, heat is generated in the integrated circuit element 52. The generated heat is conducted to the heat radiating member 54 via the heat conductive member 56 and the power generation device 50, and is radiated by the heat radiating member 54. In the power generation device 50, as in Comparative Examples 1 and 2, Example 1 and its modifications, the thermoelectric thin films (thermoelectric materials) 12a and 12b provided between the connection layers 14a and 14b are formed with the connection layer 14a. Includes thermoelectric converters alternately connected in series via 14b. One of the connection layers 14a and 14b is thermally connected to the integrated circuit element 52, and the other of the connection layers 14a and 14b is connected to the heat dissipation member 54.

As a result, power can be generated using the temperature difference between the integrated circuit element 52 and the heat radiating member 54. By using the first embodiment and its modifications as the power generation device 50, the output power of the power generation device 50 can be increased.

[Modification 1 of Example 2]
FIG. 17 is a block diagram of the electronic device according to the first modification of the second embodiment. As shown in FIG. 17, the electronic device 106 includes a control circuit 60 and a power storage device 62 in addition to the electronic device 105 according to the second embodiment. The power storage device 62 is, for example, a secondary battery. External power 70 is supplied to the control circuit 60. The control circuit 60 supplies electric power 71 to the integrated circuit element 52. The control circuit 60 may supply electric power 71 having a plurality of voltages to the integrated circuit element 52 corresponding to the power supply voltage of the integrated circuit element 52.

The heat 80 generated in the integrated circuit element 52 is conducted or transferred to the power generation device 50. In the power generation device 50, a part of heat is converted into electric power 72. The remaining heat 81 is conducted or transferred to the heat radiating member 54. The heat 82 is released from the heat radiating member 54.

The electric power 72 generated by the power generation device 50 is output to the control circuit 60. The control circuit 60 supplies the electric power 72 generated by the power generation device 50 to the power storage device 62 or the integrated circuit element 52. The power storage device 62 stores the electric power 73 supplied from the control circuit 60. Further, the power storage device 62 supplies the electric power 74 to the control circuit 60. The control circuit 60 supplies the electric power 74 supplied from the power storage device 62 to the integrated circuit element 52 as the electric power 71.

The control circuit 60 selects, for example, a charging mode and an operation assist mode. In the charging mode, the control circuit 60 mainly uses the electric power 72 generated by the power generation device 50 to charge the power storage device 62. The electric power 71 supplied to the integrated circuit element 52 mainly uses an external electric power 70. In the charging mode, the power consumption rate of the power storage device 62 can be relaxed. Alternatively, the charging time of the power storage device 62 can be shortened as compared with the case where the power storage device 62 is charged only by an external power source.

In the operation assist mode, the control circuit 60 supplies the power 72 generated by the power generation device 50 and / or the power 74 discharged by the power storage device 62 to the integrated circuit element 52 in addition to the external power 70. In the operation assist mode, if the operation speed of the integrated circuit element 52 is the same, the consumption of the external power 70 can be suppressed (that is, the power consumption is low) as compared with the case where the operation assist mode such as the charging mode is not used. If the external power 70 is the same, the integrated circuit element 52 can be operated at a higher speed (that is, the voltage is boosted by thermoelectric power generation). Further, the energy recovered from the thermoelectric conversion device can be used to retain the data in the memory in the integrated circuit when the integrated circuit goes to sleep. For this data retention, the operation assist mode and the energy from the battery can also be utilized.

According to the first modification of the second embodiment, the power storage device 62 stores the electric power generated by the power generation device 50 and supplies the stored electric power to the integrated circuit element 52. This enables low power consumption and / or high speed operation.

[Modification 2 of Example 2]
FIG. 18 is a block diagram of the electric power system according to the second modification of the second embodiment. As shown in FIG. 18, the power system 108 includes a control circuit 60 and a power recovery device 64 in addition to the electronic device 105. The control circuit 60 supplies external power 70 to the integrated circuit element 52. The electric power recovery device 64 recovers the electric power 72 generated by the power generation device 50 in the plurality of electronic devices 105. The electric power recovery device 64 supplies the electric power 75 in which the recovered electric power 72 is integrated to the outside.

In a data center or the like, a huge number of integrated circuit elements 52 such as a microprocessor are operating. Therefore, a huge amount of electric power is consumed. Therefore, a part of the heat generated in the integrated circuit element 52 is converted into the electric power 72 in the power generation device 50. The electric power 72 is recovered and reused. The electric power 75 to be reused is used for electric power such as air conditioning or lighting in a data center or the like. Even if the recovered electric power 72 is about 10% of the electric power consumed by the integrated circuit element 52, it can be sufficiently used as electric power for air conditioning or lighting.

[Simulation using a homeothermic animal model]
In the simulations of Comparative Example 1 and Example 1, the temperature difference ΔT applied to the thermoelectric conversion device is constant. This model is one of the evaluation methods for a single thermoelectric power generation module. However, when the thermoelectric conversion device is used as a power source for the wearable device, the thermoelectric conversion device generates electricity by using the temperature difference between the body temperature of the human body and the temperature of the atmosphere. In such a case, the above simulation is not appropriate. Therefore, using a homeothermic animal model for the skin temperature of the human body, a simulation of the thermoelectric conversion device in Example 1 was performed.

19 (a) and 19 (b) are diagrams showing a simulation model. 19 (a) and 19 (b) show a constant heat flow model and a constant temperature difference model, respectively. The constant heat flow corresponds to a constant current source model when expressed by an equivalent electric circuit, and the constant temperature difference corresponds to a constant voltage source model when expressed by an equivalent electric circuit. A constant current source model is generally used to evaluate the performance of thermoelectric converters.

As shown in FIG. _19A , the thermal resistances km and _air are connected in series. km and _air correspond to the thermal resistance of the _{thermoelectric} converter and the thermal resistance between the thermoelectric converter and the atmosphere, respectively. A constant current source 66 (that is, a constant heat flow source) is provided in series with the thermal resistances _km and _air . In the constant current source model, the constant current source 66 applies a power Q to one end of the _thermal resistance km to keep the heat flow flowing through the _km and the _air constant. The power Q corresponds to the power input to the thermoelectric conversion device from the skin of the human body. However, in the constant current source model, the temperature of the skin surface changes depending on the _magnitude of the thermal resistance km. This cannot represent the human body, which is a homeothermic animal. Therefore, for example, when the thermal resistance _km is large, a large power Q is applied to keep the heat flow constant. However, the power input from the human body is limited, and the constant current source model is not suitable as a simulation model of the power supply for wearable devices.

As shown in FIG. 19B, a constant voltage source 68 (that is, a constant temperature difference source) is provided in series with the thermal resistance _km and _air . In the constant voltage source model, considering that the human body is a homeothermic animal, the temperature of the skin surface of the human body is kept constant by keeping the temperature difference between the outside air and the skin surface constant. That is, the constant voltage source 68 keeps the thermal resistance _km and the temperature difference _ΔTS applied to the _air constant. The temperature difference ΔT applied to both sides of the thermoelectric converter varies depending on the thermal resistance _km and _air , but the temperature of the skin surface can be kept constant.

The structure of Example 1 is shown in FIGS. 4 (a) and 4 (b), and the structure of Comparative Example 1 is shown in FIGS. 2 (a) and 2 (b).
The simulation conditions are shown below.
Atmospheric thermal resistance _kair : 212.5K / W
Thermoelectric thin films 12a and 12b
_Seebeck coefficient S ₌ Sp-Sn: 434 μV / K
Thermal conductivity λ = (λ _p + λ _n ) / 2: 1.43 Wm ^-1 K ^-1
Electrical resistivity ρ = (ρ _p + ρ _n ) / 2: 8.11 μΩm
Connection layers 14a and 14b: Cu
Film thickness t _Cu : 10 μm (Example 1), ≦ 10 μm (Comparative Example 1)
Thermal conductivity λ _Cu : 386Wm ^-1 K ^-1
Electrical resistivity λ _Cu : 1.69 × ^10-8 Ωm
Insulation layer 18: Vacuum D x D: 10 mm x 10 mm
_ΔTS : 10K
Sn and Sp are the Seebeck coefficients of the _n -type and _p -type thermoelectric thin films 12a and 12b, respectively, λ _n and λ _p are the thermal conductivitys of the n-type and p-type thermoelectric thin films 12a and 12b, respectively, and ρ _n and ρ. _p is the electrical resistivity of the n-type and p-type thermoelectric thin films 12a and 12b, respectively. D is the length of one side of the module.

As described above, in the homeothermic animal model, the temperature difference _ΔTS between the surface temperature of the skin and the outside air temperature was kept constant at 10K. This corresponds to, for example, a case where the body temperature is 35 ° C and the temperature is 25 ° C. The thermal resistance _kair of convection from the base of the thermoelectric converter and heat dissipation due to radiation was kept constant at 212.5 K / W regardless of the temperature.

[Simulation of Example 1]
A simulation was performed for Example 1 using a homeothermic animal model. Similar to the simulation with constant ΔT, the optimization was performed with the trade-off parameter γ that maximizes the output power P _OUT and the element logarithm m ₀ that maximizes the output power P _OUT .

20 (a) and 20 (b) are diagrams showing simulation results of γd, (1-γ) d, ΔT, _βΔT , VS and P _OUT for γ and m ₀ , respectively, in Example 1. βΔT is the temperature difference between both ends of the thermoelectric thin films 12a and 12b. Other parameters are the same as in the simulation in which ΔT is constant.

FIG. 20A is a diagram when γ is optimized at m ₀ = 100 pairs and t ₀ = 100 nm. As shown in FIG. 20 (a), when γ changes, P _OUT changes. The γ that maximizes P _OUT is the optimized γ. When P _OUT did not have a peak with respect to γ, γ having the maximum P _OUT within the range of γ d ≧ 1 μm and (1-γ) d ≧ 1 μm was defined as the optimized γ.

FIG. 20 (b) is a diagram when m ₀ is optimized at t ₀ = 100 nm. Gamma is optimized by the method shown in FIG. 20 (a) for each m ₀ . As shown in FIG. 20 (b), P _OUT changes when m ₀ changes. As shown in the figure, since m ₀ that takes the peak of _{P OUT} and VS is different, for example, m ₀ that is in the range of VS ≧ 100 mV and has the maximum _{P OUT} can be set as the optimized m ₀ . can.

FIG. 21 is a diagram showing simulation results of γd, (1-γ) d, ΔT, _βΔT , VS and P _OUT with respect to t ₀ in Example 1. For each t ₀ , m ₀ is optimized by the method shown in FIG. 20 (b). As shown in FIG. 21, P _OUT is 100 μW or more when the film thickness t ₀ is 300 nm or less.

[Simulation of Comparative Example 1]
A simulation was performed for the π-type of Comparative Example 1 in the same manner as in Example 1 using a homeothermic animal model. FIG. 22 is a diagram showing simulation results of γd, (1-γ) d, ΔT, _βΔT , VS and P _OUT with respect to t ₀ in Comparative Example 1. Here, the minimum values of γd and (1-γ) d are limited to 1 μm. As shown in FIG. 22, as the film thickness t ₀ becomes smaller, P _OUT becomes smaller. When the film thickness t ₀ is 1000 nm or less, P _OUT becomes 100 μW or less.

As described above, even when the simulation using the homeothermic animal model was used, the same result as the simulation result in which ΔT was constant was obtained. That is, in the first embodiment, the output power P _OUT hardly depends on the film thickness t ₀ . On the other hand, in Comparative Example 1, the output power P _OUT becomes smaller as the film thickness t ₀ becomes smaller.

In Example 1, the reason why the output power P _OUT can be increased even if the film thickness t ₀ of the thermoelectric thin films 12a and 12b is made smaller than that of Comparative Example 1 will be described.

23 (a) and 23 (b) are schematic cross-sectional views of the thermoelectric conversion device according to Comparative Example 1 and Example 1, respectively. As shown in FIGS. 23 (a) and 23 (b), the direction of the temperature difference ΔT is the Z direction in both Comparative Example 1 and Example 1. In Comparative Example 1, the direction in which the heat flow of the thermoelectric thin films 12a and 12b flows is the same Z direction as the temperature difference ΔT. In the first embodiment, the flow direction of the heat flow of the thermoelectric thin films 12a and 12b is the X direction intersecting the temperature difference ΔT.

In Comparative Example 1, as shown in FIG. 23A, when the film thickness t ₀ of the thermoelectric thin films 12a and 12b is reduced to reduce the thickness of the thermoelectric thin films 12a and 12b, the thermal resistance k of the thermoelectric thin films 12a and 12b becomes smaller. The temperature difference βΔT between both ends of the thermoelectric thin films 12a and 12b becomes small. As shown in FIG. 22, when the film thickness t ₀ becomes smaller, the temperature difference ΔT generated in the entire thermoelectric conversion device (module) becomes smaller, but the temperature difference ΔT becomes smaller than the temperature difference ΔT. As a result, the output power P _OUT becomes small.

In Example 1, as shown in FIG. 23 (b), when the film thickness t ₀ of the thermoelectric thin films 12a and 12b is reduced to reduce the thickness of the thermoelectric thin films 12a and 12b, the thermal resistance k of the thermoelectric thin films 12a and 12b increases. As a result, as shown in FIG. 21, the temperature difference ΔT generated in the entire thermoelectric conversion device is large, and the temperature difference βΔT and the temperature difference ΔT between both ends of the thermoelectric thin films 12a and 12b are almost the same. As a result, the output power P _OUT does not decrease even if the film thickness t ₀ becomes smaller.

FIG. 24 is a diagram showing a current I and an output power P _OUT with respect to the output voltage V _out in the first embodiment. The film thickness t ₀ is set to 100 nm, and the area S of the XY plane is changed from 20 cm ² to 120 cm ² in 20 cm ² steps. The maximum value of the output power P _OUT is the output power when the output is impedance-matched. As shown in FIG. 24, when the output voltage V _out is 1 V, the output power P _OUT peaks. The mounting area of the wristband type wearable device is about 100 cm ² . Even if the area S is about 100 cm ² , an output power P _OUT of about 10 mW can be obtained, and it can be sufficiently applied to a health care device or a wearable device including short- and medium-distance communication.

In Comparative Example 1, the simulation was performed without the conditions of γd ≧ 1 μm and (1-γ) d ≧ 1 μm. FIG. 25 is a diagram showing simulation results of γd, (1-γ) d, ΔT, _βΔT , VS and P _OUT with respect to the minimum dimension in Comparative Example 1. The minimum dimension corresponds to d. The film thickness t ₀ was set to 100 nm. Also in Comparative Example 1, when the minimum dimension is reduced, the temperature difference ΔT of the entire thermoelectric converter becomes large, and the temperature difference βΔT generated in the thermoelectric material becomes small. As a result, the difference between the temperature difference βΔT and ΔT becomes small, and the output power P _OUT becomes large. For example, when the minimum dimension is 1 μm or less, the output power P _OUT is 20 μW or more. When the minimum dimension is 100 nm or less, the temperature difference βΔT and ΔT are substantially the same, and the output power P _OUT is 100 μW or more.

As described above, even in Comparative Example 1, if the minimum dimension is reduced, the output power P _OUT can be improved. However, if the minimum dimension is smaller than the micron order (for example, 1 μm), the cost for microfabrication will increase. In the first embodiment, the output power P _OUT can be increased even if the minimum dimension is 1 μm or more, and high output power can be realized at low cost.

As shown in FIGS. 2A and 2B, the thermoelectric thin films 12a and 12b are arranged in the plane direction of the bases 22a and 22b. The connecting layers 14a and 14b are thermally connected to the bases 22a and 22b, respectively, and are alternately thermally and electrically connected to the thermoelectric thin films 12a and 12b in the direction intersecting the plane direction (Z direction). .. In such a π-type thermoelectric conversion device, as shown in FIG. 25, the output power is set by setting the pitch (period: for example, dimensions γd and / or (1-γ) d) of the thermoelectric thin films 12a and 12b to 1 μm or less. P _OUT can be increased. The size of the thermoelectric thin films 12a and 12b is preferably 0.5 μm or less, more preferably 0.1 μm or less. Since the thermoelectric thin films 12a and 12b are manufactured by the thin film technology, the film thickness _t0 of the thermoelectric thin films 12a and 12b is preferably 10 μm or less, more preferably 5 μm or less. Further, the film thicknesses of the thermoelectric thin films 12a and 12b formed by using the semiconductor integrated circuit manufacturing technique are preferably 1 μm or less, more preferably 500 nm or less, still more preferably 200 nm or less. As shown in FIG. 25, the output power P _OUT can be increased even when the film thickness t0 is 100 nm.

26 (a) is a plan view of the thermoelectric conversion device according to the fourth embodiment, and FIG. 26 (b) is a sectional view taken along the line AA of FIG. 26 (a). FIG. 26 (a) shows the bases 22a and 22b and the thermoelectric conversion unit 44. As shown in FIGS. 26 (a) and 26 (b), a thermoelectric conversion unit 44 is provided between the bases 22a and 22b. The thermoelectric conversion unit 44 has the thermoelectric thin films 12a and 12b, the connecting layers 14a and 14b, and the insulating layer 18 as in FIGS. 2 (a) and 2 (b) of Comparative Example 1. The area of the thermoelectric conversion unit 44 is made smaller than that of the bases 22a and 22b in a plan view. A thermal insulator 46 is provided in a portion between the bases 22a and 22b other than the thermoelectric conversion unit 44. The thermal insulator 46 has a lower thermal conductivity than the thermoelectric thin films 12a and 12b, the connection layers 14a and 14b, and the bases 22a and 22b. Thus, the thermal insulator 46 is an electrical and thermal insulator. The size of the bases 22a and 22b is D0 × D0, and the size of the thermoelectric conversion unit 44 is D × D.

For Example 4, a simulation was performed using a homeothermic animal model. In the simulation, D0 = 1 cm, t ₀ = 100 nm, _ΔTS was 10 K, the thermal insulator 46 and the insulating layer 18 were evacuated, and γd ≧ 1 μm and (1-γ) d ≧ 1 μm. Optimization was performed with γ and m ₀ .

FIG. 27 is a diagram showing simulation results of γd, (1-γ) d, ΔT, _βΔT , VS and P _OUT with respect to D in Example 4. As shown in FIG. 27, even if the thermoelectric conversion unit 44 has the same π type as in Comparative Example 1, if D is made small, the output power P _OUT becomes large. When the thermoelectric conversion unit 44 is π-shaped, when the thermoelectric thin films 12a and 12b are uniformly dispersed in the region of D0 × D0, the connecting layers 14a and 14b that electrically connect the thermoelectric thin films 12a and 12b become long, and the inside becomes long. The impedance becomes high. When the thermoelectric thin films 12a and 12b are housed in a narrow range of D × D as in the fourth embodiment, the connection layers 14a and 14b are shortened, and the internal impedance can be reduced.

[Modification 1 of Example 4]
28 (a) is a plan view of the thermoelectric conversion device according to the first modification of the fourth embodiment, and FIG. 28 (b) is a sectional view taken along the line AA of FIG. 28 (a). FIG. 28 (a) shows the bases 22a and 22b and the thermoelectric conversion unit 44. As shown in FIGS. 28 (a) and 28 (b), the thermoelectric conversion unit 44 has the same thermoelectric thin films 12a and 12b and the connecting layer 14a as in FIGS. 4 (a) and 4 (b) of the first embodiment. It has 14b, a heat conductive layer and an insulating layer. The area of the thermoelectric conversion unit 44 is made smaller than that of the bases 22a and 22b in a plan view. The thermal insulator 46 has a lower thermal conductivity than the thermoelectric thin films 12a and 12b, the connection layers 14a and 14b, and the bases 22a and 22b. The size of the bases 22a and 22b is D × D, and the length of the thermoelectric conversion unit 44 is L.

A simulation was performed using a homeothermic animal model for Modification 1 of Example 4. In the simulation, D = 1 cm, t ₀ = 100 nm, _ΔTS is 10 K, and the insulating layers 18a and 18b in the thermoelectric conversion unit 44 are porous silicon (thermal conductivity is 35.7 mWm ^-1 K ^-1 ), and the thermal insulator is used. 46 was porous silicon or vacuum, and γd ≧ 1 μm and (1-γ) d ≧ 1 μm. Optimization was performed with γ and m ₀ .

FIG. 29 (a) is a diagram showing the simulation results of t _Cu , _γd , m ₀ , VS and P _OUT with respect to L in the modified example 1 of Example 4, and FIG. 29 (b) is a diagram showing L, γd with respect to t _Cu . , M ₀ , VS and _{P OUT} simulation results. The insulating layers 18a and 18b and the thermal insulator 46 in the thermoelectric conversion unit 44 were made of porous silicon. As shown in FIG. 29 (a), when the thermal insulator 46 is porous silicon, the output power P _OUT increases when L is reduced. In this example, when L is about 30 μm, the output power P _OUT becomes maximum. As shown in FIG. 29 (b), when L is about 30 μm and t _Cu is about 500 μm, the output power P _OUT becomes maximum at about 20 μW. When the thermal insulator 46 is porous silicon, P _OUT increases by increasing t _Cu in order to suppress the heat flow through the thermal insulator 46, but if t _Cu is too large, the thermal resistance of the heat conductive layer increases. P _OUT has a peak because it becomes large.

FIG. 30 is a diagram showing simulation results of L, _γd , m ₀ , VS and P _OUT with respect to t _Cu when the thermal insulator 46 is in a vacuum. The insulating layers 18a and 18b in the thermoelectric conversion unit 44 were made of porous silicon. As shown in FIG. 30, when L and t _Cu become smaller, the output power P _OUT becomes smaller. When L and t _Cu are about 0.1 μm, the output power P _OUT is about 100 μW. As described above, when the thermal insulator 46 is evacuated, the output power P _OUT becomes large. Since the heat flow through the thermal insulator 46 hardly flows, the output power P _OUT can be increased even if t _Cu is thin.

[Modification 2 of Example 4]
FIG. 31 is a cross-sectional view of the thermoelectric conversion device according to the second modification of the fourth embodiment. As shown in FIG. 31, a holding wall 47 for holding between the bases 22a and 22b in a vacuum 46a is provided. Other configurations are the same as those of the fourth embodiment and the first modification thereof, and the description thereof will be omitted.

According to Example 4 and modifications 1 and 2 thereof, the base 22a (first base) is thermally connected to the surface of a living body of a homeothermic animal such as a human body. The base 22b (second base) is thermally connected to the atmosphere (air). The thermoelectric conversion unit 44 (thermoelectric conversion unit) is provided between the bases 22a and 22b. The thermal insulator 46 is provided between the base 22a and the base 22b and outside the thermoelectric conversion unit 44, and has a thermal conductivity smaller than the thermal conductivity of the thermoelectric thin films 12a, 12b, the base 22a, and the base 22b. As a result, the output power P _OUT can be improved as shown in the simulation results of FIGS. 27 and 29 (a) to 30.

The thermal insulator 46 may completely surround the thermoelectric conversion unit 44 in a plan view as shown in FIG. 26 (a) of the fourth embodiment. The thermal insulator 46 may be provided only on both sides of the thermoelectric conversion unit 44 in a plan view as shown in FIG. 28 (a) of the first modification of the fourth embodiment. The thermal insulator 46 may be provided on only one side of the thermoelectric conversion unit 44. The width of the thermoelectric conversion unit 44 in the X direction may be smaller than D. That is, at least one of the thermoelectric conversion units 44 in the ± X direction may be provided with a thermal insulator 46. In both the cases of FIGS. 26 (a) and 28 (a), the area of the thermoelectric conversion unit 44 is preferably 1/10 or less, more preferably 1/100 or less of the area of the bases 22a and 22b in a plan view.

As the thermal insulator 46, the materials of the insulating layers 18a and 18b exemplified in Example 1 can be used. For example, the thermal insulator 46 may be a solid layer such as porous silicon. As the porous silicon, for example, porous silicon using high resistance silicon or porous silicon which becomes an insulator electrically and thermally by oxidation or the like can be used. Thereby, the bases 22a and 22b can be reinforced. As the solid layer, a porous layer such as porous silica other than porous silicon can be used.

Further, as in the modified example 2 of the fourth embodiment, the thermal insulator 46 is a gas layer or a vacuum having a pressure lower than the atmospheric pressure, and the holding wall 47 (holding portion) holds the vacuum. As a result, the thermal conductivity of the thermal insulator 46 can be reduced as compared with the case where the thermal insulator 46 is a solid layer. Therefore, as shown in FIG. 30, the output power P _OUT can be increased. The thermal insulator 46 may be atmospheric pressure air or other gas (eg, nitrogen, etc.). Also in Example 4, the thermal insulator 46 may be vacuum, atmospheric pressure air or other gas. Further, in the fourth embodiment and its modifications, the insulating layers 18, 18a and 18b (see FIG. 4 (b) and the like) in the thermoelectric conversion unit 44 may be vacuum, air or other gas in addition to the solid.

The thermal insulator 46 and the insulating layers 18, 18a and 18b may be made of the same material or different materials. The insulating layers 18, 18a and 18b may be solid layers for holding the thermoelectric thin films 12a and 12b, and the connecting layers 14a and 14b, and the thermal insulator 46 may be an air layer or a vacuum for increasing the output power P _OUT .

[Modification 3 of Example 4]
32 (a) is a plan view of the thermoelectric conversion device according to the third modification of the fourth embodiment, and FIG. 32 (b) is a sectional view taken along the line AA of FIG. 32 (a). As shown in FIGS. 32 (a) and 32 (b), a plurality of thermoelectric conversion units 44 corresponding to the thermoelectric conversion units 44 of the fourth embodiment are provided between the single base 22a and the single base 22b. ing. Each thermoelectric conversion unit 44 is surrounded by a thermal insulator 46 in a plan view. The plurality of thermoelectric conversion units 44 may be electrically connected in series or in parallel.

[Modification 4 of Example 4]
33 (a) is a plan view of the thermoelectric conversion device according to the modified example 4 of the fourth embodiment, and FIG. 33 (b) is a sectional view taken along the line AA of FIG. 33 (a). As shown in FIGS. 33 (a) and 33 (b), the thermoelectric conversion unit 44 corresponding to the thermoelectric conversion unit 44 of the first modification of the fourth embodiment between the single base 22a and the single base 22b. Are provided in multiples. Each thermoelectric conversion unit 44 is surrounded by a thermal insulator 46 in a plan view. The plurality of thermoelectric conversion units 44 may be electrically connected in series or in parallel.

According to the modifications 3 and 4 of the fourth embodiment, a plurality of thermoelectric conversion units 44 are provided between the bases 22a and 22b so as to be separated from each other via the thermal insulator 46. These interconnects allow the output voltage and power to be set appropriately.

Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the specific examples thereof, and various modifications are made within the scope of the gist of the present invention described in the claims.・ Can be changed.

10 Zeebeck element 12a, 12b Thermoelectric thin film 14a, 14b Connection layer 16a, 16b Thermal conduction layer 18, 18a, 18b Insulation layer 20 Insulation film 22a, 22b Base 24a, 24b Electrode 28a, 28b Groove 44 Thermoelectric conversion unit 46 Thermal insulation 47 Holding wall 50 Power generation device 52 Integrated circuit element 54 Heat dissipation member 60 Control circuit 62 Power storage device

Claims (11)

The first thermoelectric thin film and the second thermoelectric thin film having opposite conductive types alternately provided in the first direction parallel to the surfaces of the first thermoelectric thin film and the second thermoelectric thin film.
A first connection layer that is electrically and thermally connected to the first thermoelectric thin film and the second thermoelectric thin film between the first thermoelectric thin film and the second thermoelectric thin film, and is alternately provided in the first direction. And the second connection layer,
A first heat conductive layer and a second heat conductive layer that are thermally connected to the first connecting layer and the second connecting layer, respectively, and extend in a second direction intersecting the surface.
Equipped with
The first heat conductive layer and the second heat conductive layer are provided on opposite sides to the surfaces of the first thermoelectric thin film and the second thermoelectric thin film.
A solid first insulator through which the first heat conductive layer penetrates and has a lower thermal conductivity than the first heat conductive layer.
A solid second insulator through which the second heat conductive layer penetrates and has a lower thermal conductivity than the second heat conductive layer.
A first base portion and a second base portion thermally connected to the first heat conductive layer and the second heat conductive layer, respectively.
Equipped with
The first base and the first insulator have a first groove between the first heat conductive layers.
The thermoelectric conversion device, wherein the second base portion and the second insulator have a second groove between the second heat conductive layers. A plurality of layers including the first thermoelectric thin film, the second thermoelectric thin film, the first connecting layer, the second connecting layer, the first heat conductive layer and the second heat conductive layer are laminated in a direction intersecting the surface. Being done
The first heat conductive layer included in one of the adjacent layers among the plurality of layers and the second heat conductive layer contained in the other of the adjacent layers are thermally connected. The thermoelectric conversion device according to claim 1. The first thermoelectric thin film, the second thermoelectric thin film, the first connecting layer, the second connecting layer, the first heat conductive layer and the second thermoelectric thin film are provided between the first base portion and the second base portion. A thermoelectric conversion unit provided with a heat conductive layer, wherein the first heat conductive layer and the second heat conductive layer are connected to the first base portion and the second base portion, respectively.
Between the first base and the second base, which is provided outside the thermoelectric conversion unit, the thermal conductivity of the first thermoelectric thin film, the second thermoelectric thin film, the first base and the second base. With a thermal insulator with lower thermal conductivity,
Equipped with
The first base is thermally connected to the surface of the living body of a homeothermic animal.
The thermoelectric conversion device according to claim 1 or 2 , wherein the second base is thermally connected to air . The first base and
The second base and
A first thermoelectric material provided between the first base and the second base, provided between the first connection layer and the second connection layer, and a conductive type opposite to the first thermoelectric material. The two thermoelectric materials are alternately connected in series via the first connection layer and the second connection layer, and the first connection layer and the second connection layer are the first base portion and the second base portion, respectively. With a thermoelectric conversion unit thermally connected to
Between the first base and the second base, provided outside the thermoelectric conversion unit in plan view, the first thermoelectric material, the second thermoelectric material, the first base and the second base. With a thermal insulator that has a thermal conductivity lower than that of the thermal conductivity,
Equipped with
The thermal insulator contacts the first base portion and the second base portion in a region outside the thermoelectric conversion unit in a plan view, and the area of the thermoelectric conversion unit in a plan view is the thermoelectric conversion unit and the thermal insulator. A thermoelectric conversion device characterized in that the area of the region where the first base portion and the second base portion face each other is 1/100 or less of the area of the first base portion and the second base portion. The thermoelectric conversion device according to claim 4, wherein the thermal insulator is a solid layer. The thermoelectric conversion device according to claim 4, wherein the thermal insulator is a gas layer or a vacuum having a pressure lower than atmospheric pressure. The first base and
The second base and
A first thermoelectric material provided between the first base and the second base, provided between the first connection layer and the second connection layer, and a conductive type opposite to the first thermoelectric material. The two thermoelectric materials are alternately connected in series via the first connection layer and the second connection layer, and the first connection layer and the second connection layer are the first base portion and the second base portion, respectively. With a thermoelectric conversion unit thermally connected to
A gas layer or vacuum between the first base and the second base, which is provided outside the thermoelectric conversion unit and has a pressure lower than atmospheric pressure, and is a region outside the thermoelectric conversion unit in a plan view. In the thermal insulator that comes into contact with the first base and the second base,
A holding portion provided between the first base portion and the second base portion so as to surround the thermoelectric conversion unit and the thermal insulator to hold the gas layer or the vacuum.
Equipped with
In a plan view, the area of the thermoelectric conversion unit is 1/100 or less of the area of the region where the first base portion and the second base portion face each other via the thermoelectric conversion unit and the thermal insulator. Converter. The thermoelectric conversion according to any one of claims 4 to 7, wherein a plurality of the thermoelectric conversion units separated from each other via the thermal insulator are provided between the first base portion and the second base portion. Device. The first thermoelectric material and the second thermoelectric material are alternately provided in the first direction parallel to the surface of the first base portion and the second base portion.
The first connecting layer and the second connecting layer are electrically and thermally connected to the first thermoelectric material and the second thermoelectric material between the first thermoelectric material and the second thermoelectric material. Alternately provided in the first direction
The thermoelectric conversion unit includes a first heat conductive layer and a second heat conductive layer that are thermally connected to the first connection layer and the second connection layer, respectively, and extend in a second direction intersecting the surface. The thermoelectric conversion device according to any one of claims 4 to 8, wherein the thermoelectric conversion device is characterized. The first thermoelectric material and the second thermoelectric material are arranged in the plane direction of the first base portion and the second base portion.
A claim characterized in that the first connecting layer and the second connecting layer are alternately thermally and electrically connected to the first thermoelectric material and the second thermoelectric material in a direction intersecting the plane direction. Item 6. The thermoelectric conversion device according to any one of Items 4 to 8. The first base is thermally connected to the surface of the living body of a homeothermic animal.
The thermoelectric conversion device according to any one of claims 4 to 10, wherein the second base is thermally connected to air.

Images