WO2015166783A1

WO2015166783A1 - Thermoelectric conversion element, thermoelectric conversion module, and method for manufacturing thermoelectric conversion element

Info

Publication number: WO2015166783A1
Application number: PCT/JP2015/061210
Authority: WO
Inventors: 修米倉; 林　直之; 加納　丈嘉; 青合　利明
Original assignee: 富士フイルム株式会社
Priority date: 2014-04-30
Filing date: 2015-04-10
Publication date: 2015-11-05
Also published as: JP6174246B2; JPWO2015166783A1

Abstract

This invention comprises the following: a first substrate that, in the plane thereof, has a high-thermal-conductivity section that exhibits higher thermal conductivity than other regions of said first substrate; a first contact layer; a thermoelectric conversion layer comprising nickel or a nickel alloy; a second contact layer; and a second substrate that, in the plane thereof, has a high-thermal-conductivity section that exhibits higher thermal conductivity than other regions of said second substrate and does not completely overlap the high-thermal-conductivity section of the first substrate. This makes it possible to provide the following: a thermoelectric conversion element and a thermoelectric conversion module that can generate electricity efficiently and exhibit good flexibility; and a method for manufacturing said thermoelectric conversion element.

Description

Thermoelectric conversion element, thermoelectric conversion module, and method of manufacturing thermoelectric conversion element

The present invention relates to a thermoelectric conversion element. Specifically, the present invention relates to a thermoelectric conversion element capable of obtaining a high power generation amount and having good flexibility, a thermoelectric conversion module using the thermoelectric conversion element, and a method for manufacturing the thermoelectric conversion element.

Thermoelectric conversion materials that can mutually convert thermal energy and electrical energy are used in thermoelectric conversion elements such as power generation elements and Peltier elements that generate electricity by heat.
The thermoelectric conversion element can convert heat energy directly into electric power, and has an advantage that a movable part is not required. For this reason, a power generation device that uses a thermoelectric conversion element can be easily obtained without incurring operating costs by providing it at a site where heat is exhausted, such as an incinerator or various facilities in a factory.

A thermoelectric conversion element generally has an electrode on a plate-like substrate, a block-like thermoelectric conversion layer (power generation layer) on the electrode, and a plate-like electrode on the thermoelectric conversion layer. It has the structure which has. This thermoelectric conversion element is also called a uni leg type.
That is, in a normal thermoelectric conversion element, a thermoelectric conversion layer is sandwiched between electrodes in the thickness direction, a temperature difference is generated in the thickness direction of the thermoelectric conversion layer, and heat energy is converted into electric energy.

On the other hand, in Patent Document 1 and Patent Document 2, by using a substrate having a high heat conduction portion, a temperature difference is generated not in the thickness direction of the thermoelectric conversion layer but in the surface direction of the thermoelectric conversion layer, A thermoelectric conversion element that converts energy into electrical energy is described.
Specifically, in Patent Document 1, a flexible film substrate composed of two types of materials having different thermal conductivities is provided on both surfaces of a thermoelectric conversion layer formed of a P-type material and an N-type material. A thermoelectric conversion element is described in which materials having different thermal conductivities are arranged on the outer surface of the substrate and at positions opposite to the energizing direction.

Patent Document 2 discloses a sheet-like first insulating portion, a sheet-like second insulating portion, a first end portion for taking out a thermoelectromotive force accommodated between both insulating portions, and A plate-like thermoelectric conversion layer having a second end, and a first insulating portion that is disposed between the thermoelectric conversion layer and the first insulating portion and covers the first insulating portion side of the first end. Covering the second insulating portion side of the second end portion of the plate-like member, which is disposed between the first high thermal conductivity portion having a higher thermal conductivity than the plate-like member and the second insulating portion, An element having a second high thermal conductivity portion having a higher thermal conductivity than the second insulating portion is described.

Japanese Patent No. 3981738 JP 2011-35203 A

As described above, the thermoelectric conversion element generates power by generating a temperature difference in the separation direction of the electrodes connected to the thermoelectric conversion layer, that is, the energization direction. In addition, the larger the temperature difference, the higher the power generation amount.
Therefore, in a general thermoelectric conversion element having a configuration in which a thermoelectric conversion layer is sandwiched between electrodes, in order to cause a large temperature difference in the thermoelectric conversion layer, it is necessary to increase the thickness of the thermoelectric conversion layer in the electrode sandwiching direction. There is.

On the other hand, the thermoelectric conversion elements described in Patent Document 1 and Patent Document 2 generate a temperature difference in the surface direction of the thermoelectric conversion layer by the high heat conduction portion provided on the substrate, and convert the heat energy into electric energy. To do.
Therefore, even in a thin sheet-like thermoelectric conversion layer, a long temperature difference can be generated by making the thermoelectric conversion layer long, and a high power generation amount can be obtained. Furthermore, since the thermoelectric conversion layer can be formed into a sheet shape, a power generator that is excellent in flexibility and easy to install on a curved surface or the like can be obtained.

On the other hand, in Patent Document 1 and Patent Document 2, an alloy containing a rare metal is used for the thermoelectric conversion layer, which is difficult in terms of versatility of the material. For example, in Patent Document 1, CePd ₃ —YbPd is used for the thermoelectric conversion layer. In Patent Document 2, (Bi ₂ Te ₃ ) _1-x (Sb ₂ Te ₃ ) _x and (Bi ₂ Te are used for the thermoelectric conversion layer. ₃ ) _1-x (Sb ₂ Te ₃ ) _x is used.

An object of the present invention is to use a thermoelectric conversion layer made of a highly versatile material, to obtain a high power generation amount, and to have good flexibility, a thermoelectric conversion module using the thermoelectric conversion element, and It is in providing the manufacturing method of this thermoelectric conversion element.

In order to achieve such an object, the thermoelectric conversion element of the present invention includes a first substrate having a high thermal conductivity portion having a thermal conductivity higher than that of other regions in at least a part of the surface direction,
A first adhesion layer formed on the first substrate;
A thermoelectric conversion layer made of nickel or a nickel alloy formed on the first adhesion layer;
A second adhesion layer formed on the thermoelectric conversion layer;
The high adhesion portion formed on the second adhesion layer and having a thermal conductivity higher than that of other regions is provided in at least a part of the surface direction, and the high heat conduction portion of the first substrate is formed in the surface direction. A second substrate that does not completely overlap with the high thermal conductivity part;
A thermoelectric conversion element comprising a pair of electrodes connected to a thermoelectric conversion layer so as to sandwich the thermoelectric conversion layer in a plane direction is provided.

In such a thermoelectric conversion element of the present invention, the nickel content of the thermoelectric conversion layer is preferably 90 atomic% or more.
Moreover, it is preferable that a thermoelectric conversion layer is formed with nickel.
In addition, it is preferable that the high thermal conductivity portion of the first substrate and the high thermal conductivity portion of the second substrate are provided at different positions in the plane direction in the electrode separation direction.
Moreover, it is preferable that the high heat conduction part of a 1st board | substrate and the high heat conduction part of a 2nd board | substrate are located in an outer surface with respect to the lamination direction.
Moreover, it is preferable that the surface of the first substrate on the first adhesion layer side has been subjected to a roughening treatment.
Further, the arithmetic average roughness Ra of the surface of the first substrate on the first adhesion layer side is preferably 0.9 μm or more.

Also, the thermoelectric conversion module of the present invention provides a thermoelectric conversion module formed by connecting a plurality of thermoelectric conversion elements of the present invention in series.

In such a thermoelectric conversion module of the present invention, it is preferable to have a radiating fin in contact with either one of the first substrate and the second substrate and the high thermal conduction portion.
Moreover, it is preferable that the radiation fin and the high thermal conductive portion are bonded with a thermal conductive adhesive sheet or a thermoconductive adhesive.

In addition, the method for manufacturing a thermoelectric conversion element of the present invention includes a step of forming a first adhesion layer on a first substrate having a high thermal conductivity portion having a higher thermal conductivity than at other regions in at least a part of a plane direction.
Forming a thermoelectric conversion layer made of nickel or a nickel alloy on the first adhesion layer;
Connecting the electrode pair to the thermoelectric conversion layer so as to be sandwiched in the surface direction,
Forming a second adhesion layer on the thermoelectric conversion layer;
And on the 2nd adhesion layer, it has a high heat conduction part whose heat conductivity is higher than other fields in at least a part of the surface direction, and its own high heat conduction part is the first substrate in the surface direction. And a step of laminating the second substrate so as not to completely overlap with the high thermal conductivity portion.

In such a method for manufacturing a thermoelectric conversion element of the present invention, the thermoelectric conversion layer is preferably formed by a vapor deposition method.
In addition, prior to the formation of the first adhesion layer, it is preferable to perform a roughening treatment on the surface of the first substrate on which the first adhesion layer is formed.
Further, it is preferable that the roughening treatment is performed so that the arithmetic average roughness Ra of the surface of the first substrate on which the first adhesion layer is formed is 0.9 μm or more.

Such a thermoelectric conversion element and thermoelectric conversion module according to the present invention has a thin sheet-like thermoelectric conversion element made of nickel or a nickel alloy having high versatility, so that a high power generation amount can be obtained and a good potential can be obtained. It has flexibility.
Moreover, according to the manufacturing method of the thermoelectric conversion element of this invention, such a thermoelectric conversion element of this invention can be manufactured suitably.

1A is a top view conceptually showing an example of the thermoelectric conversion element of the present invention, FIG. 1B is a front view thereof, and FIG. 1C is a bottom view thereof. 2A to 2D are conceptual diagrams for explaining an example of the thermoelectric conversion module of the present invention using the thermoelectric conversion element of the present invention. FIG. 3A and FIG. 3B are front views conceptually showing another example of a substrate that can be used in the thermoelectric conversion element of the present invention.

Hereinafter, the thermoelectric conversion element, the thermoelectric conversion module, and the method for manufacturing the thermoelectric conversion element of the present invention will be described in detail based on the preferred embodiments shown in the accompanying drawings.

FIG. 1 conceptually shows an example of the thermoelectric conversion element of the present invention. 1A is a top view (a view of FIG. 1B viewed from above), FIG. 1B is a front view (a view of a substrate or the like described later), and FIG. C) is a bottom view (a view of FIG. 1B viewed from the lower side of the drawing).

As shown in FIGS. 1A to 1C, the thermoelectric conversion element 10 basically includes a first substrate 12, a first adhesion layer 14, a thermoelectric conversion layer 16, and a second adhesion layer 18. And the second substrate 20, the electrode 26 and the electrode 28.
Specifically, the first adhesion layer 14 is provided on the first substrate 12, the thermoelectric conversion layer 16 is provided on the first adhesion layer 14, and the second adhesion layer 18 is provided on the thermoelectric conversion layer 16. And has a second substrate 20 on the second adhesion layer 18. Further, the thermoelectric conversion layer 16 is sandwiched between the first substrate 12 and the second substrate 20 (the first adhesion layer 14 and the second adhesion layer 18) in the substrate surface direction of the first substrate 12 and the second substrate 20. The electrode 26 and the electrode 28 are connected to the thermoelectric conversion layer 16. That is, the electrode 26 and the electrode 28 constitute an electrode pair.
Hereinafter, the substrate surface directions of the first substrate 12 and the second substrate 20 are also simply referred to as “surface directions”.

As shown in FIG. 1, the 1st board | substrate 12 has the low heat conduction part 12a and the high heat conduction part 12b. Similarly, the 2nd board | substrate 20 also has the low heat conduction part 20a and the high heat conduction part 20b. In the illustrated example, the two substrates are arranged such that their high thermal conductivity portions are at different positions in the direction in which the electrode 26 and the electrode 28 are separated from each other. The separation direction of the electrode 26 and the electrode 28 is the energization direction.
In addition, since both boards differ only in the arrangement position and the orientation of the front and back sides and the surface direction, and the configuration is the same, unless it is necessary to distinguish between the first board 12 and the second board 20, The description will be made using the first substrate 12 as a representative example.

In the illustrated thermoelectric conversion element 10, the first substrate 12 (second substrate 20) covers a region on one half of one surface of the plate-like material that becomes the low thermal conduction portion 12 a (low thermal conduction portion 20 a). It has a configuration in which the high heat conduction part 12b (high heat conduction part 20b) is laminated.
Therefore, on one surface (one surface) of the first substrate 12, a half region in the plane direction is the low heat conduction portion 12a, and the other half region is the high heat conduction portion 12b. In addition, the other surface of the first substrate 12 is the low thermal conductive portion 12a.
In addition, in the thermoelectric conversion element of this invention, various structures can be utilized for the 1st board | substrate (2nd board | substrate) besides the structure formed by laminating | stacking a high heat conduction part on the surface of a low heat conduction part. For example, as conceptually shown in FIG. 3 (A), the first substrate is formed with a recess in a half region of one surface of the plate-like material that becomes the low heat conducting portion 12a, The structure which incorporates the high heat conductive part 12b so that may become uniform may be sufficient.
Further, the first substrate is a laminated body shown in FIG. 1A, and the second substrate is a first substrate and a second substrate, such as a configuration in which a high heat conduction portion is incorporated in the concave portion shown in FIG. The method for forming the high thermal conductivity portion may be different.

The low heat conduction part 12a is made of various materials as long as it has insulating properties and sufficient heat resistance to the formation of the thermoelectric conversion layer 16 and the electrode 26, such as a glass plate, a ceramic plate, and a plastic film. A thing consisting of can be used.
Preferably, a plastic film is used for the low thermal conductive portion 12a. By using a plastic film for the low heat conducting portion 12a, it is possible to reduce the weight and cost, and to form the thermoelectric conversion element 10 having flexibility (flexibility), which is preferable.

Specific examples of the plastic film that can be used for the low thermal conductive portion 12a include polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, polybutylene terephthalate, poly (1,4-cyclohexylenedimethylene terephthalate), polyethylene-2, Polyester resin such as 6-phthalenedicarboxylate, polyimide, polycarbonate, polypropylene, polyether sulfone, cycloolefin polymer, polyether ether ketone (PEEK), triacetyl cellulose (TAC) resin, glass epoxy, liquid crystalline polyester, etc. The film (sheet-like material / plate-like material) consisting of is exemplified.
Among them, a film made of polyimide, polyethylene terephthalate, polyethylene naphthalate, or the like is suitably used in terms of thermal conductivity, heat resistance, solvent resistance, availability, economy, and the like.

As long as the high heat conductive part 12b has a heat conductivity higher than the low heat conductive part 12a, the film and metal foil which consist of various materials are illustrated.
Specifically, various metals such as gold, silver, copper, and aluminum are exemplified in terms of thermal conductivity and the like. Among these, copper and aluminum are preferably used in terms of thermal conductivity, economy, and the like.

In the present invention, the thickness of the first substrate 12, the thickness of the low thermal conductive portion 12 a, and the like are appropriately determined according to the forming material of the high thermal conductive portion 12 b and the low thermal conductive portion 12 a, the size of the thermoelectric conversion element 10, and the like. , You can set. In addition, the thickness of the 1st board | substrate 12 is the thickness of the low heat conductive part 12a of the area | region which does not have the high heat conductive part 12b. According to the study by the present inventors, the thickness of the first substrate 12 is preferably 2 to 50 μm, more preferably 2 to 25 μm, and more preferably 2 to 20 μm.
Further, the size in the surface direction of the first substrate 12, the area ratio in the surface direction of the high heat conducting portion 12 b in the substrate 12, the forming material of the low heat conducting portion 12 a and the high heat conducting portion 12 b, the size of the thermoelectric conversion element 10, etc. It may be set appropriately according to the above. The size in the surface direction of the first substrate 12 is a size when the first substrate 12 is viewed from a direction orthogonal to the substrate surface.

Furthermore, the position of the first substrate 12 in the surface direction of the high thermal conductive portion 12b is not limited to the illustrated example, and various positions can be used.
For example, in the 1st board | substrate 12, the high heat conductive part 12b may be included in the low heat conductive part 12a in the surface direction. Alternatively, a part of the high heat conduction unit 12b may be located at the end of the first substrate 12 in the plane direction, and the other region may be included in the low heat conduction unit 12a.
Further, the first substrate 12 may have a plurality of high heat conducting portions 12b in the surface direction.

Note that the thermoelectric conversion element 10 shown in FIG. 1 is a preferable mode in which a temperature difference between the first substrate 12 and the second substrate 20 is likely to occur, and both the first substrate 12 and the second substrate 20 have high thermal conductivity. The part 12b and the high heat conduction part 20b are located outside in the stacking direction.
However, the present invention may have a configuration in which the first substrate 12 and the second substrate 20 both have the high heat conduction portion 12b and the high heat conduction portion 20b located inside in the stacking direction. Alternatively, the first substrate 12 may be configured such that the high heat conductive portion 12b is positioned outside in the stacking direction, and the second substrate 20 is positioned such that the high heat conductive portion 20b is positioned inside in the stacking direction.
In the case where the high thermal conductivity portion is formed of a material having conductivity such as metal and disposed inside the stacking direction, and the first adhesion layer 14 and / or the second adhesion layer 18 are electrically conductive. May have. In this case, an insulating layer or the like may be formed between the high heat conduction portion and the electrode 26 and the electrode 28 in order to ensure insulation.

In the thermoelectric conversion element 10, the thermoelectric conversion layer 16 is provided on the first substrate 12 via the first adhesion layer 14. A second substrate 20 is provided on the thermoelectric conversion layer 16 with a second adhesion layer 18 interposed therebetween.
That is, in the thermoelectric conversion element 10, the first adhesion layer 14 is provided between the first substrate 12 and the thermoelectric conversion layer 16. In the thermoelectric conversion element 10, a second adhesion layer 18 is provided between the second substrate 20 and the thermoelectric conversion layer 16.

The formation surface of the first adhesion layer 14 of the first substrate 12 is preferably subjected to a roughening treatment. That is, in the illustrated example, it is preferable that the surface of the first substrate 12 on the side where the high thermal conductive portion 12b is not formed is a surface roughened.
In particular, the surface of the first substrate 12 on which the first adhesion layer 14 is formed preferably has an arithmetic average roughness Ra of 0.9 μm or more. Furthermore, the formation surface of the first adhesion layer 14 of the first substrate 12 is more preferably 1.5 μm or more.
The formation surface of the first adhesion layer 14 of the first substrate 12 is subjected to a roughening treatment, so that an anchor effect occurs due to the unevenness of the surface, and the first substrate 12 and the thermoelectric conversion Adhesion with the layer 16, the electrode 26, and the electrode 28 can be improved.
In addition, what is necessary is just to measure arithmetic mean roughness Ra based on JISB0601 (2001). Further, as will be described later in detail, the roughening treatment may be performed by a known method.

As will be described later, the thermoelectric conversion layer 16 of the thermoelectric conversion element 10 of the present invention is made of nickel or a nickel alloy. Hereinafter, “nickel” is referred to as “Ni”. The first adhesion layer 14 and the second adhesion layer 18 are for ensuring sufficient adhesion between the thermoelectric conversion layer 16 and the first substrate 12 and the second substrate 20.
The first adhesion layer 14 and the second adhesion layer 18 will be described in detail later.

In the thermoelectric conversion element 10, the thermoelectric conversion layer 16 is provided on the first substrate 12 via the first adhesion layer 14. In other words, the thermoelectric conversion layer 16 is a power generation layer. A second substrate 20 is provided on the thermoelectric conversion layer 16 with a second adhesion layer 18 interposed therebetween. Note that, as described above, both the substrates have the high thermal conductivity portion located outside in the stacking direction. Therefore, one surface of the thermoelectric conversion layer 16 faces the surface where the entire surface of the first substrate 12 becomes the low heat conduction portion 12a, and the other surface faces the surface where the entire surface of the second substrate 20 becomes the low heat conduction portion 20a. To do.
The thermoelectric conversion layer 16 is provided in such a manner that the center in the plane direction coincides with the boundary between the low thermal conductivity portion and the high thermal conductivity portion of both substrates.
The thermoelectric conversion layer 16 is connected to an electrode pair including the electrode 26 and the electrode 28 so as to be sandwiched in the surface direction.

The thermoelectric conversion element generates a temperature difference between the heated part and the other part due to, for example, heating by contact with a heat source, etc. A difference occurs in the carrier density in the direction of the temperature difference, and electric power is generated. In the illustrated example, for example, a heat source is provided on the first substrate 12 side, and a temperature difference is generated between the high heat conduction portion 12b of the first substrate 12 and the high heat conduction portion 20b of the second substrate 20, thereby generating power. To do. Further, by connecting wiring to the electrode 26 and the electrode 28, electric power (electric energy) generated by heating or the like is taken out.

In the thermoelectric conversion element 10 of the present invention, the thermoelectric conversion layer 16 is made of Ni or a Ni alloy.
The thermoelectric conversion element 10 of the present invention uses two substrates having a high heat conduction portion and a low heat conduction portion, and places the high heat conduction portions of both substrates in different positions in the plane direction, and sandwiches the thermoelectric conversion layer between the two substrates. The thermoelectric conversion has a structure and is formed of Ni or Ni alloy so that a high power generation amount can be obtained using a highly versatile material and the flexibility is excellent. The device is realized.
Hereinafter, a configuration in which two substrates having a high heat conduction portion and a low heat conduction portion are used, and the high heat conduction portions of both the substrates are located at different positions in the plane direction, and the thermoelectric conversion layer is sandwiched between the two substrates, “in Also called “plane type”.

Ni and Ni alloys are known to have high power generation due to temperature differences. That is, Ni and Ni alloys are known to have a large Seebeck coefficient. Ni and Ni alloys are also known to have high electrical conductivity.
In the thermoelectric conversion layer, the higher the Seebeck coefficient and the higher the electrical conductivity, the higher the amount of power generated. Therefore, it is conceivable that a thermoelectric conversion element capable of obtaining a high power generation amount can be obtained by using Ni or a Ni alloy for the thermoelectric conversion layer.
However, Ni and Ni alloys have high thermal conductivity.

As described above, a normal thermoelectric conversion element has a configuration in which a block-shaped thermoelectric conversion layer is sandwiched between electrodes. In such a thermoelectric conversion element, by increasing the thickness of the thermoelectric conversion layer, the temperature difference generated in the thermoelectric conversion layer in the direction of separation between the electrodes can be increased. The separation direction between the electrodes is the separation direction of the electrode pair. Hereinafter, the separation direction between the electrodes is also referred to as “inter-electrode direction”.
However, Ni and Ni alloys have high thermal conductivity. Therefore, in a normal thermoelectric conversion element using a block-shaped thermoelectric conversion layer, if Ni or a Ni alloy is used for the thermoelectric conversion layer, even if the thermoelectric conversion layer is made thick, it causes a temperature difference in the thermoelectric conversion layer. It is difficult to.
Therefore, in a normal thermoelectric conversion element in which a block-shaped thermoelectric conversion layer is sandwiched between electrodes, Ni or Ni alloy having high thermal conductivity cannot be used for the thermoelectric conversion layer, and a material having as low thermal conductivity as possible is used. It is used to form a thermoelectric conversion layer.

On the other hand, in the thermoelectric conversion element 10 of the present invention which is an in-plane type, the first substrate 12 has a high heat conduction part 12b, and the second substrate 20 has a high heat conduction part 20b, and the high heat conduction part 12b and the high heat conduction part 12b. The conductive portion 20b is arranged at a different position in the plane direction without overlapping. Therefore, for example, when a heat source is provided on the first substrate 12 side, a temperature difference is generated in the surface direction of the thermoelectric conversion layer 16 between the high thermal conductivity portion 12b and the high thermal conductivity portion 20b. That is, in the thermoelectric conversion element 10 of the present invention that is an in-plane type, the heat is applied in the surface direction of the sheet-like thermoelectric conversion layer 16 as conceptually shown by the arrow x in FIGS. Flows.
Therefore, the thermoelectric conversion element 10 of the present invention can cause a large temperature difference in the thermoelectric conversion layer 16 between the electrodes by the sheet-like thermoelectric conversion layer 16 without increasing the thickness of the thermoelectric conversion layer 16. Further, by making the thermoelectric conversion layer 16 longer in the inter-electrode direction, a higher power generation amount can be obtained due to a temperature difference over a long distance in the surface direction.

Here, according to the study by the present inventors, in the in-plane type thermoelectric conversion element, even if the thermoelectric conversion layer is formed of a material having high thermal conductivity such as Ni or Ni alloy, the temperature in the thermoelectric conversion layer is reduced. A difference can be made.
Like water and electricity, heat also flows more easily as the path through which it travels, that is, the flow path, is larger. Further, the shorter the heat flow path, the easier the heat transfer and the less the temperature difference in the flow direction.
In the in-plane type thermoelectric conversion element 10, the thermoelectric conversion layer 16 is not a block shape but a thin sheet shape. Therefore, in the in-plane type thermoelectric conversion element 10, since the heat flow path in the thermoelectric conversion layer 16 is narrow and it is difficult for heat to flow, a temperature difference is easily generated in the thermoelectric conversion layer 16.
In addition, as described above, the in-plane type thermoelectric conversion element 10 is one of the advantages that good flexibility is obtained. In order to obtain good flexibility, the thermoelectric conversion layer is used. 16 is advantageously thinner. That is, by making the thermoelectric conversion layer 16 thinner, a temperature difference can be easily generated, and flexibility can be improved. Moreover, in the in-plane type thermoelectric conversion element 10, as described above, in order to obtain a large temperature difference, it is advantageous that the thermoelectric conversion layer 16 between the electrodes is long. Temperature differences are likely to occur.

That is, the thermoelectric conversion element 10 of the present invention is an in-plane type, so that even if Ni or Ni alloy having high thermal conductivity is used, a temperature difference can be generated in the thermoelectric conversion layer 16 and a high power generation amount can be obtained. Can be obtained.

Here, the in-plane type thermoelectric conversion element 10 has a configuration in which the thermoelectric conversion layer 16 is sandwiched between a first substrate 12 and a second substrate 20 having a high heat conduction portion and a low heat conduction portion. As described above, the low thermal conductive portion 12a and the low thermal conductive portion 20a of the first substrate 12 and the second substrate 20 are formed of a glass plate, a ceramic plate, a plastic film, or the like.
However, Ni and Ni alloys have low adhesion to these materials. Therefore, when the thermoelectric conversion layer 16 is formed in direct contact with the first substrate 12 and the second substrate 20, the thermoelectric conversion layer 16 is peeled off during the formation, and an appropriate thermoelectric conversion layer cannot be formed. Is peeled off by bending or bending, and the thermoelectric conversion element is broken.

On the other hand, the thermoelectric conversion element 10 of the present invention has the first adhesion layer 14 between the thermoelectric conversion layer 16 and the first substrate 12, and further between the thermoelectric conversion layer 16 and the second substrate 20. 2 has a second adhesion layer 18. Therefore, the thermoelectric conversion layer 16 and the first substrate 12 and the second substrate 20 can be stacked with sufficient adhesion.
As a result, an appropriate thermoelectric conversion layer 16 made of Ni or Ni alloy can be formed, and even if bending and the like are repeated, peeling of the thermoelectric conversion layer 16 from the first substrate 12 and the second substrate 20 occurs. The thermoelectric conversion element 10 excellent in flexibility can be obtained.

That is, the thermoelectric conversion element 10 of the present invention adopts an in-plane type, forms the thermoelectric conversion layer 16 with Ni or Ni alloy, and further, between the thermoelectric conversion layer 16 and the first substrate 12 and the second substrate 20. The first adhesion layer 14 and the second adhesion layer 18 have a large temperature difference in the thermoelectric conversion layer 16 which is a general-purpose material and has a high thermal conductivity but a high power generation amount and a high conductivity. This produces a high power generation amount, and also realizes good flexibility, which is one of the features of the in-plane type.

In the thermoelectric conversion element 10 of the present invention, the thermoelectric conversion layer 16 is made of Ni or Ni alloy.
As the Ni alloy, various Ni alloys that generate electric power by generating a temperature difference can be used. Specifically, examples include one component such as V, Cr, Si, Al, Ti, Mo, Mn, Zn, Sn, Cu, Co, Fe, Mg, and Zr, or a Ni alloy mixed with two or more components. Is done.

Here, in the thermoelectric conversion element 10 of the present invention, the thermoelectric conversion layer 16 preferably has a Ni content of 90 atomic% or more, more preferably a Ni content of 95 atomic% or more, and is made of Ni. Is particularly preferred. In addition, what consists of Ni includes what consists of Ni and an unavoidable impurity.
By setting the Ni content of the thermoelectric conversion layer 16 to 90 atomic% or more, a high internal conductivity of Ni is utilized to reduce the internal resistance of the thermoelectric conversion layer 16, thereby obtaining a high power generation amount with a small internal resistance. Since the thermoelectric conversion layer 16 can be made thin while maintaining it, it is preferable in that the thermoelectric conversion element 10 can be made thin, and the thermoelectric conversion module using this can be made thinner, lighter and more flexible (flexible).

The thermoelectric conversion layer 16 preferably has a Seebeck coefficient S of −15 μV / K or less and a conductivity σ of 10,000 S / cm or more.
The thermoelectric conversion layer 16 having such characteristics is preferable in that a high power generation amount can be obtained by reducing the internal resistance of the thermoelectric conversion layer 16 by utilizing the high conductivity of Ni. In addition, since the thermoelectric conversion layer 16 has such characteristics, the thermoelectric conversion element 16 can be made thin while maintaining a small internal resistance by utilizing the high conductivity of Ni, and thus the thermoelectric conversion element 10 can be made thin. The thermoelectric conversion module using this is also preferable in that it can be made thin, light, and flexible.

In the thermoelectric conversion element 10 of the present invention, the thickness of the thermoelectric conversion layer 16, the length in the direction between the electrodes, the length in the direction orthogonal to this length, the size in the surface direction, the area ratio in the surface direction with respect to the substrate, etc. What is necessary is just to set suitably according to the magnitude | size, use, etc. of the thermoelectric conversion element 10. FIG.

Here, in the thermoelectric conversion element 10 of the present invention, when the length of the thermoelectric conversion layer 16 in the inter-electrode direction is L and the thickness of the thermoelectric conversion layer 16 is T, as shown in FIG. The aspect ratio of L / T is preferably 100 to 2000, the aspect ratio of L / T is more preferably 200 to 1000, and the aspect ratio of L / T is particularly preferably 200 to 500. . The thickness of the thermoelectric conversion layer 16 is the size of the thermoelectric conversion layer 16 in the stacking direction of the first substrate 12, the thermoelectric conversion layer 16, and the second substrate 20.
As described above, in order to increase the temperature difference between the electrodes of the thermoelectric conversion layer 16, it is advantageous that the thermoelectric conversion layer 16 is thin, and it is advantageous that the thermoelectric conversion layer 16 is long between the electrodes. is there. Therefore, it is preferable that the L / T aspect ratio in the thermoelectric conversion layer 16 is within the above range in that a large temperature difference is generated in the thermoelectric conversion layer 16 and a higher power generation amount can be obtained.

Further, according to the study by the present inventors, the thickness T of the thermoelectric conversion layer 16 is preferably 0.05 to 4 μm, more preferably 1 to 2 μm.
By setting the thickness T of the thermoelectric conversion layer 16 within this range, it is preferable in that a higher power generation amount can be obtained, and the thermoelectric conversion element 10 having good flexibility can be obtained.

The first adhesion layer 14 and the second adhesion layer 18 have sufficient adhesion strength between the first substrate 12 and the second substrate 20 and the thermoelectric conversion layer 16 according to the forming materials of the first substrate 12 and the second substrate 20. There are various types of materials that can be obtained.
Specifically, examples include various metal oxides such as silicon oxide, aluminum oxide, tantalum oxide, and zirconium oxide, and layers made of various metals such as chromium, copper, and titanium.
In addition, an adhesion layer using a liquid adhesive or an adhesion layer using a film-like adhesive or an adhesive sheet can be suitably used as the first adhesion layer 14 and the second adhesion layer 18. These adhesives may use commercially available products.
Among these, the first adhesion layer 14 and the second adhesion layer 18 are preferably a layer made of silicon oxide and a layer made of chromium, and a layer made of silicon oxide is particularly preferable.
Note that the materials for forming the first adhesion layer 14 and the second adhesion layer 18 may be the same or different.

The thickness of the first adhesion layer 14 and the second adhesion layer 18 depends on the forming material of the first adhesion layer 14 and the second adhesion layer 18, the forming material and the size of the first substrate 12 and the second substrate 20, and the like. The thickness capable of obtaining sufficient adhesion may be set as appropriate.
According to the study by the present inventors, it is preferable that the adhesion layer be thin if a sufficient adhesion amount is obtained. Specifically, 50 to 500 nm is preferable, and 100 to 200 nm is more preferable.
By setting the thickness of the first adhesion layer 14 and the second adhesion layer 18 in this range, it is preferable in that sufficient adhesion can be obtained, and the thermoelectric conversion element 10 having good flexibility can be obtained.
In addition, the interface between the first substrate 12 and the first adhesion layer 14, the interface between the first adhesion layer 14 and the thermoelectric conversion layer 16, the interface between the thermoelectric conversion layer 16 and the second adhesion layer 18, and the second adhesion layer 18 In order to improve the adhesion at one or more of the interfaces with the second substrate 20, a known surface treatment such as plasma treatment, UV ozone treatment, electron beam irradiation treatment is applied to the surface of the substrate and / or the surface of the adhesion layer. The surface may be modified or cleaned.

The first adhesion layer 14 and / or the second adhesion layer 18 may be formed corresponding to the entire surface of the first substrate 12 and the second substrate 20 as in the illustrated example. The two substrates 20 may be formed only in a region corresponding to the thermoelectric conversion layer 16.

An electrode 26 and an electrode 28 are connected to the thermoelectric conversion layer 16 so as to sandwich the thermoelectric conversion layer 16 in the surface direction.

The electrode 26 and the electrode 28 can be formed of various materials as long as they have a necessary conductivity.
Specifically, materials used as transparent electrodes in various devices such as metal materials such as copper, silver, gold, platinum, nickel, chromium, and copper alloys, and indium tin oxide (ITO) and zinc oxide (ZnO). Etc. are exemplified. Especially, copper, gold | metal | money, platinum, nickel, a copper alloy etc. are illustrated preferably, and copper, gold | metal | money, platinum, nickel is illustrated more preferably. Among these, copper is particularly preferably exemplified in that a high power generation amount is obtained.

Further, the thickness and size of the electrode 26 and the electrode 28 may be appropriately set according to the thickness of the thermoelectric conversion layer 16 and the size of the thermoelectric conversion element 10.

In the illustrated example, the thermoelectric conversion element 10 faces the abutting direction between the electrodes, and the high heat conduction portion 12b of the first substrate 12 and the high heat conduction portion 20b of the second substrate 20 face each other in the interelectrode direction. Located in different positions.
In addition to this, the thermoelectric conversion element of the present invention can be used in various configurations as long as the high thermal conductivity portion of the first substrate and the high thermal conductivity portion of the second substrate do not completely overlap in the plane direction. . In other words, in the thermoelectric conversion element of the present invention, the high heat conduction part of the first substrate and the high heat conduction part of the second substrate do not completely overlap when viewed from the surface direction, that is, the direction orthogonal to the substrate surface. Various configurations are available. Also in the following example, the high heat conduction part may be placed on the low heat conduction part as shown in FIG. 1 (B), or the low heat conduction part as shown in FIG. 3 (A). You may incorporate in the formed recessed part.

For example, in the example shown in FIG. 1, the high heat conduction portion 12 b of the first substrate 12 is moved to the right side in the drawing, the high heat conduction portion 20 b of the second substrate 20 is moved to the left side in the drawing, The conductive portion may be separated in the direction between the electrodes. Specifically, the high heat conduction part 12b of the first substrate 12 and the high heat conduction part 20b of the second substrate 20 are in the plane direction with respect to the size of the thermoelectric conversion layer 16 in the direction in which the electrode 26 and the electrode 28 are separated from each other. Thus, it is preferably 10 to 90% apart in the direction between the electrodes, and more preferably 10 to 50% apart.
Alternatively, in the configuration in which both the high heat conductive portions are separated from each other, the high heat conductive portion 12b and / or the high heat conductive portion 20b are provided with a convex portion directed to the other, so that the high heat conductive portions of both the substrates partially overlap in the surface direction. It may be.

On the other hand, in the example shown in FIG. 1, the high heat conduction portion 12b of the first substrate 12 is moved to the left side in the drawing, and the high heat conduction portion 20b of the second substrate 20 is moved to the right side in the drawing, A part of the conductive portion may overlap in the surface direction.

In addition, in the present invention, various configurations can be used as long as the high thermal conductivity portion of the first substrate and the high thermal conductivity portion of the second substrate do not completely overlap in the plane direction.
For example, a circular high thermal conductivity portion is formed on the first substrate, a square high thermal conductivity portion of the same size is formed on the second substrate, and the two substrates are mounted so that the centers of both high thermal conductivity portions coincide in the plane direction. You may arrange. Even in this configuration, although the distance is short, since the end (periphery) positions of the two high heat conducting portions are different in the surface direction, a temperature difference in the surface direction is generated in the thermoelectric conversion layer, and a temperature difference is generated in the thickness direction. Efficient power generation is possible compared to thermoelectric conversion elements. In addition, the circle and square of the same size are a circle and a square with the same diameter and the length of one side.

Furthermore, the thermoelectric conversion element of the present invention has a gas barrier layer, an antioxidant layer, a protective layer (passivation film) and the like for preventing deterioration of the thermoelectric conversion layer 16, the electrode 26, the electrode 28, and the like, if necessary. May be.
These layers are, for example, between the thermoelectric conversion layer 16 and the first adhesion layer 14 and the second adhesion layer 18, between the first adhesion layer 14 and the first substrate 12, and between the second adhesion layer 18 and the second adhesion layer 18. What is necessary is just to provide in the outer surface side of the 1st board | substrate 12 and the 2nd board | substrate 20, etc. between the board | substrates 20.
Examples of these layers include a silicon oxide layer, an aluminum oxide layer, a silicon nitride layer, and a zirconium oxide layer.
Therefore, for example, when the first adhesion layer 14 and / or the second adhesion layer 18 is formed of silicon oxide or aluminum oxide, the adhesion layer also functions as a gas barrier layer.

FIGS. 2A to 2D show an example of the thermoelectric conversion module of the present invention in which a plurality of such thermoelectric conversion elements 10 of the present invention are connected in series. 2A to 2C are top views and FIG. 2D is a front view.
In this example, the first substrate 12A and the second substrate 20A have a rectangular plate-like low thermal conductive material on the surface of a long rectangular pillar-shaped high thermal conductive portion and a length of one side in contact with the low thermal conductive portion of the rectangular pillar. It has a configuration that is arranged at equal intervals in a direction orthogonal to the longitudinal direction of the quadrangular prism.
That is, in the first substrate 12A and the second substrate 20A, the entire surface of one surface is a low heat conductive portion, and the other surface is a direction in which a long low heat conductive portion and a high heat conductive portion are orthogonal to the longitudinal direction. The structure is alternately formed at equal intervals (see FIGS. 2A, 2C, and 2D).
Also in this example, the first substrate (second substrate) can use various configurations other than the configuration in which the high thermal conductivity portion is placed on the surface of the low thermal conductivity portion. For example, as conceptually shown in FIG. 3B, the first substrate is a rectangular plate-like low heat conductive material in one direction (a direction perpendicular to the paper surface of FIG. 3B). A configuration in which long grooves are formed at equal intervals with the width of the grooves in a direction orthogonal to the longitudinal direction, and a high heat conductive material is incorporated in the grooves may be employed.

As conceptually shown in FIGS. 2B and 2C, the thermoelectric conversion layer 16 has a rectangular surface shape, and the entire surface of the first substrate 12A is on the surface on the side that is the low thermal conductive portion 12a. The boundary and the center of the low heat conduction part 12a and the high heat conduction part 12b are made to correspond in the surface direction. The surface on the side where the entire surface of the first substrate 12A is the low thermal conductive portion 12a is the upper surface in a state where FIG.
In the illustrated example, the horizontal size of the thermoelectric conversion layer 16 in FIG. 2B is the same as the width of the high thermal conductive portion 12b. Hereinafter, the horizontal direction in FIG. 2B is also simply referred to as “lateral direction”. In other words, the horizontal direction is an alternately arranged direction of the low heat conducting portions 12a and the high heat conducting portions 12b.
The thermoelectric conversion layer 16 is formed at equal intervals every other boundary with respect to the boundary between the low thermal conductivity portion 12a and the high thermal conductivity portion 12b in the lateral direction. The thermoelectric conversion layers 16 are formed at equal intervals in the horizontal direction at the same interval as the width of the high thermal conduction portion 12b. The width of the high heat conducting portion 12b and the lateral size of the thermoelectric conversion layer 16 are equal.
Further, the thermoelectric conversion layers 16 are two-dimensionally formed so that the rows of the thermoelectric conversion layers 16 arranged at equal intervals in the horizontal direction are arranged at equal intervals in the vertical direction in FIG. . Hereinafter, the vertical direction in FIG. 2B is also simply referred to as “vertical direction”. In other words, the up and down direction is the longitudinal direction of the low heat conduction portion 12a and the high heat conduction portion 12b.
Further, as shown in FIG. 2 (B), the horizontal arrangement of the thermoelectric conversion layers 16 is shifted in the horizontal direction by the width of the high thermal conductive portion 12b in the columns adjacent in the vertical direction. That is, in the columns adjacent in the vertical direction, the thermoelectric conversion layers 16 are alternately formed by the width of the high heat conduction portion 12b.
Note that a first adhesion layer 14 is formed on the entire surface of the first substrate 12A on which the thermoelectric conversion layer 16 is formed.

Each thermoelectric conversion layer 16 is connected in series by an electrode 26 (electrode 28). Specifically, as shown in FIG. 2B, in the arrangement of the thermoelectric conversion layers 16 in the horizontal direction in the figure, the electrodes 26 are provided so as to sandwich the thermoelectric conversion layers 16 in the horizontal direction. Thereby, the thermoelectric conversion layers 16 arranged in the lateral direction are connected in series by the electrode 26. Note that in FIG. 2B, the electrode 26 is shaded in order to clarify the configuration.
Further, the thermoelectric conversion layers 16 in the rows adjacent in the vertical direction are connected by the electrodes 26 at the lateral ends of the thermoelectric conversion layers 16. In the connection of the vertical thermoelectric conversion layer 16 by the electrode 26 at the end of the horizontal row, the thermoelectric conversion layer 16 at one end is connected to the thermoelectric conversion layer 16 at the same end of the upper row. The thermoelectric conversion layer 16 at the other end is connected to the thermoelectric conversion layer 16 at the same end in the lower row.
Thereby, all the thermoelectric conversion layers 16 are connected in series like the one line | wire folded in multiple times in the horizontal direction.

Further, as conceptually shown in FIG. 2 (A), on the thermoelectric conversion layer 16 and the electrode 26, the side of the second substrate 20A where the entire surface is the low heat conduction portion 20a is directed downward, and the low heat conduction portion. The second substrate 20A is laminated such that the boundary between 12a and the high thermal conductivity portion 12b coincides with the first substrate 12A. This stacking is performed so that the high thermal conductive portion 12b of the first substrate 12A and the high thermal conductive portion 20b of the second substrate 20A are alternated.
Although not shown, prior to the lamination of the second substrate 20A, the second adhesion layer 18 is formed on the thermoelectric conversion layer 16 and the electrode 26 so as to cover the entire first substrate 12A.

Therefore, the low heat conduction part 12a of the first substrate 12A and the region of the second substrate 20A only with the high heat conduction part 20b are aligned in the plane direction and face each other, and the high heat conduction part 12b of the first substrate 12A and the second substrate 20A The region of only the low heat conducting portion 20a faces the surface direction in alignment.
Thereby, the thermoelectric conversion module formed by connecting many thermoelectric conversion elements 10 of this invention in series is comprised.

Here, as described above, the arrangement of the thermoelectric conversion layers 16 in the horizontal direction is shifted in the horizontal direction by the width of the high heat conduction portion 12b (that is, the high heat conduction portion 20b) in the columns adjacent in the vertical direction. Is done. That is, in the columns adjacent in the vertical direction, the thermoelectric conversion layers 16 are alternately formed by the width of the high heat conduction portion 12b.
For this reason, the thermoelectric conversion layers 16 connected in series as a single folded line have all the thermoelectric conversion layers 16 in the flow in one direction of the connection direction, and one half of the thermoelectric conversion layers 16 is the high thermal conductivity of the first substrate 12A. The portion 12b faces the region of the second substrate 20A only of the low heat conduction portion 20a, and the other half faces the region of only the low heat conduction portion 12a of the first substrate 12A and the high heat conduction portion 20b of the second substrate 20A. .
For example, when viewed in the serial connection direction from the top to the bottom of FIG. 2 (B), as shown in FIGS. 2 (A) to 2 (C), all the thermoelectric conversion layers 16 are upstream. Half of the first substrate 12A faces the region of only the high thermal conductivity portion 12b and the second substrate 20A of the low thermal conductivity portion 20a, and the half of the downstream side of the first substrate 12A of the region of only the low thermal conductivity portion 12a and the second substrate 20A. It faces the high heat conduction part 20b.
Therefore, when the heat source is arranged on the first substrate 12A side or the second substrate 20A side, the heat flow direction relative to the connection direction, that is, the flow direction of the generated electricity is the same in all the thermoelectric conversion layers 16 connected in series. And the thermoelectric conversion module can generate electricity properly.

When the thermoelectric conversion module (thermoelectric conversion element) of the present invention is bonded to a heat source to generate electric power, a heat conductive adhesive sheet or a heat conductive adhesive may be used.
There is no limitation in particular in the heat conductive adhesive sheet and heat conductive adhesive which are stuck and used for the heating side or cooling side of a thermoelectric conversion module. Therefore, a commercially available heat conductive adhesive sheet or heat conductive adhesive can be used. As the heat conductive adhesive sheet, for example, TC-50TXS2 manufactured by Shin-Etsu Silicone Co., Ltd., Hypersoft heat dissipation material 5580H manufactured by Sumitomo 3M Co., Ltd., BFG20A manufactured by Denki Kagaku Kogyo Co., Ltd., TR5912F manufactured by Nitto Denko Corporation and the like can be used. In addition, the heat conductive adhesive sheet which consists of silicone type adhesives from a heat resistant viewpoint is preferable. Examples of the thermally conductive adhesive include Scotch Weld EW 2070 manufactured by 3M, TA-01 manufactured by Inex, TCA-4105, TCA-4210, HY-910 manufactured by Cima Electronics, and SST2 manufactured by Satsuma Research Institute. -RSMZ, SST2-RSCSZ, R3CSZ, R3MZ, etc. can be used.
By using a heat conductive adhesive sheet or a heat conductive adhesive, the adhesion to the heat source is improved and the surface temperature on the heating side of the thermoelectric conversion module is increased, the cooling efficiency is improved and the cooling side of the thermoelectric conversion module is improved. Due to the effect of reducing the surface temperature, the amount of power generation can be increased.

Furthermore, a heat radiation fin (heat sink) or a heat radiation sheet made of a known material such as stainless steel, copper, or aluminum may be provided on the cooling side surface of the thermoelectric conversion module, preferably in contact with the high heat conduction portion. By using a radiation fin or the like, the low temperature side of the thermoelectric conversion module can be more suitably cooled, and the temperature difference between the heat source side and the cooling side becomes large, which is preferable in terms of further improving thermoelectric efficiency. The heat radiating fins and the heat radiating sheet are preferably bonded to the thermoelectric conversion module using the above-described heat conductive adhesive sheet or heat conductive adhesive.
As the heat radiating fins, known fins such as T-Wing manufactured by Taiyo Wire Mesh Co., Ltd., FLEXCOOL manufactured by the Business Creation Laboratory, and various fins such as corrugated fins, offset fins, waving fins, slit fins, and folding fins may be used. it can. In particular, it is preferable to use a folding fin having a fin height.
The fin height of the heat dissipating fin is preferably 10 to 56 mm, the fin pitch is 2 to 10 mm, and the plate thickness is preferably 0.1 to 0.5 mm. The heat dissipating characteristics are high, the module can be cooled, and the power generation amount is high. And it is more preferable that fin height is 25 mm or more. In addition, it is preferable to use aluminum having a plate thickness of 0.1 to 0.3 mm in view of high fin flexibility and light weight.
As the heat dissipation sheet, a known heat dissipation sheet such as a PSG graphite sheet manufactured by Panasonic Corporation, a cool staff manufactured by Oki Electric Cable Co., or a shellac α manufactured by Ceramission Corporation can be used.

Hereinafter, the manufacturing method of the thermoelectric conversion element of the present invention will be described in detail by explaining an example of the manufacturing method of the thermoelectric conversion element 10 shown in FIG.

First substrate 12 (12A) having low heat conduction part 12a and high heat conduction part 12b, and second substrate 20 (20A) having low heat conduction part 20a and high heat conduction part 20b are prepared.

The first substrate 12 and the second substrate 20 may be manufactured by a known method using photolithography, etching, film formation technology, or the like.
For example, a method of preparing the first substrate 12 and the second substrate 20 by preparing a plate material in which a low heat conductive material and a high heat conductive material are laminated and removing a part of the high heat conductive material by etching or the like is exemplified. In this case, each of the first substrate 12 and the second substrate 20 has a planar shape in which one entire surface is a low heat conduction portion, and the other surface is a convex high heat conduction on the planar low heat conduction portion. A portion is formed and has unevenness (see FIGS. 1B and 2D).
As another method, a concave portion is formed in a part of the sheet-like low thermal conductive material by etching or the like, and a high thermal conductive portion is formed by vacuum deposition or the like using a mask so as to fill the concave portion. A method for producing the second substrate 20 is exemplified. In this case, both the first substrate 12 and the second substrate 20 are planar (see FIGS. 3A and 3B).
Commercially available products can also be used for the first substrate 12 and the second substrate 20.

The first adhesion layer 14 is formed on the surface of the first substrate 12 on the side where the high thermal conductive portion 12b is not formed.
The first adhesion layer 14 is formed by a known method such as a vapor deposition method (vacuum film formation method) such as vacuum deposition or sputtering, a sol-gel method, a coating method, or a printing method, depending on the material for forming the first adhesion layer 14. What is necessary is just to form. Alternatively, as described above, the first adhesion layer 14 may be formed using a liquid adhesive or a film adhesive.

Here, prior to the formation of the first adhesion layer 14, it is preferable to subject the surface of the first substrate 12 on which the first adhesion layer 14 is formed to a roughening treatment. In other words, in the illustrated example, prior to the formation of the first adhesion layer 14, it is preferable to perform the roughening treatment on the surface of the first substrate 12 on the side where the high thermal conductive portion 12 b is not formed. The roughening treatment is particularly preferably performed so that the arithmetic average roughness Ra of the formation surface of the first adhesion layer 14 of the first substrate 12 is 0.9 μm or more, and is 1.5 μm or more. Is more preferable.
By roughening the surface of the first substrate 12 on which the first adhesion layer 14 is formed, irregularities are generated on the substrate surface, and the adhesion with the thermoelectric conversion layer and the wiring layer is improved by the anchor effect.
A known method can be used for the roughening treatment. For example, as a roughening treatment method, there is a method in which a metal foil is pressure-bonded or heat-sealed to a surface to be roughened and then transferred to a surface to be roughened by peeling or dissolving the metal surface. Illustrated. As another roughening treatment method, there is exemplified a method of forming irregularities on the surface to be roughened by irradiation with plasma, UV ozone, electron beam or the like. As another roughening treatment method, a method of forming irregularities on the surface roughened by sandblasting or the like is exemplified.

Next, the thermoelectric conversion layer 16 is formed on the first adhesion layer 14.
As described above, in the thermoelectric conversion element 10 of the present invention, the thermoelectric conversion layer 16 is made of Ni or Ni alloy. The thermoelectric conversion layer 16 is formed by a vapor deposition method such as sputtering or vacuum deposition, a printing method using an ink in which Ni or Ni alloy powder is dispersed, a method of sticking a sheet material made of Ni or Ni alloy, Ni or Ni What is necessary is just to form by the well-known method which can form the film | membrane (layer) which consists of Ni or Ni alloy, such as the method of plating an alloy.
Among these, vapor deposition methods such as sputtering and vacuum evaporation are preferably exemplified in that the thermoelectric conversion element 10 having high adhesion to the first adhesion layer 14 and excellent flexibility is obtained.
If necessary, a thermoelectric conversion layer 16 may be formed by forming a layer made of Ni or a Ni alloy foil on the first adhesion layer 14 and then performing patterning by etching or the like (see FIG. 2 (B)).

Next, the electrode 26 and the electrode 28 are formed so as to sandwich the thermoelectric conversion layer 16 in the surface direction.
The formation of the electrode 26 and the electrode 28 may be performed by a known method according to the material for forming the electrode 26 and the electrode 28.

Next, the second adhesion layer 18 is formed on the thermoelectric conversion layer 16, the electrode 26, and the electrode 28 corresponding to the entire surface of the first substrate 12 (first adhesion layer 14). Alternatively, the second adhesion layer 18 is formed only on the thermoelectric conversion layer 16.
The second adhesion layer 18 may be formed by a known method similar to that of the first adhesion layer 14 depending on the material for forming the second adhesion layer 18.

Further, the prepared second substrate 20 is attached to the thermoelectric conversion layer 16 with the side where the high heat conduction portion 20b is not formed, and the thermoelectric conversion element 10 is manufactured.

Such a thermoelectric conversion element of the present invention can be used for various applications.
Examples include various power generation applications such as hot spring thermal generators, solar thermal generators, waste heat generators, and other devices (devices) such as wristwatch power supplies, semiconductor drive power supplies, and small sensor power supplies. The Moreover, as a use of the thermoelectric conversion element of this invention, sensor element uses, such as a thermal sensor and a thermocouple, are illustrated besides a power generation use.

As described above, the thermoelectric conversion element, the thermoelectric conversion module, and the manufacturing method of the thermoelectric conversion element of the present invention have been described in detail. However, the present invention is not limited to the above-described examples, and various types can be made without departing from the gist of the present invention. Of course, improvements and changes may be made.

Hereinafter, the thermoelectric conversion element of the present invention will be described in more detail with reference to specific examples of the present invention. However, the present invention is not limited to the following examples.

[Example 1]
An adhesive-free single-sided copper-clad polyimide substrate (FELIOS R-F775, manufactured by Panasonic Electric Works Co., Ltd.) was prepared. The copper-clad polyimide substrate has a size of 60 × 60 mm, a polyimide layer thickness of 20 μm, and a copper layer thickness of 70 μm.
The copper layer of this copper-clad polyimide substrate is etched to form a copper stripe pattern having a width of 500 μm and an interval of 500 μm, as shown in FIG. 2 (A), FIG. 2 (C) and FIG. 2 (D). One substrate and a second substrate were produced.

A 200 nm-thick silicon oxide layer (SiO ₂ layer) was formed as a first adhesion layer on the entire surface of the first substrate which is a polyimide layer by EB vapor deposition (Electron Beam vapor deposition). The surface where the entire surface of the first substrate is a polyimide layer is the planar surface of the first substrate.
Next, a thermoelectric conversion layer made of Ni having a thickness of 1 μm was formed by a sputtering method using a Ni target. Note that the thermoelectric conversion layer was formed using a metal mask at an equal interval of 1770 (59 × 30) patterns of 500 × 1000 μm as conceptually shown in FIG.

Next, an electrode 26 made of gold (Au) having a thickness of 2 μm is produced by a vacuum deposition method using a metal mask, and 1770 thermoelectric conversion layers are connected in series as conceptually shown in FIG. Connected.

Further, the first substrate and the second substrate on which the thermoelectric conversion layer is formed are laminated as a second adhesion layer via a non-support adhesive sheet (SK-2478, manufactured by Soken Chemical Co., Ltd.), and an automatic press machine (TP700A, Taiyo Yu A thermoelectric conversion module in which 1770 thermoelectric conversion elements are connected in series was manufactured by bonding with a press load of 5 kN.
As shown in FIGS. 2A to 2C, the first substrate and the second substrate are laminated with a polyimide layer on the entire surface of the first substrate and the second substrate. A certain surface was faced, and the copper stripe portion of the first substrate and the portion without the copper stripe of the second substrate were aligned in the plane direction. The surface on which the entire surface of the second substrate is a polyimide layer is a planar surface of the second substrate. Further, the portion of the second substrate without the copper stripe is the portion of the second substrate made of only polyimide.

On the other hand, the electrical conductivity σ and Seebeck coefficient S of the thermoelectric conversion layer were measured by the following method.
A 15 × 4 mm thermoelectric conversion layer made of Ni having a thickness of 1 μm was formed in the center of the polyimide substrate by a sputtering method using the same Ni target.
Regarding the thermoelectric conversion layer made of Ni, the electrical conductivity σ and Seebeck coefficient S were measured using a thermoelectric property evaluation apparatus (ZEM-3, manufactured by ULVAC-RIKO). The center temperature of the substrate was 30 ° C.
As a result, the conductivity σ was 46500 S / cm and the Seebeck coefficient S was −15.4 μV / K.

The produced thermoelectric conversion module was sandwiched between a heated copper plate and a copper plate connected with a cold water circulation device, and the temperature of the heated copper plate was adjusted so that the temperature difference between both copper plates would be 10 ° C. .
Further, the electrode of the most upstream thermoelectric conversion layer and the electrode of the most downstream thermoelectric conversion layer connected in series are connected to a source meter (source meter 2450, manufactured by Keithley), and the open circuit voltage and the short circuit current are measured. The power generation amount was obtained from the following formula.
(Power generation amount) = 0.25 × (open circuit voltage) × (short circuit current)
As a result, the power generation amount was 43.4 μW.

After measuring the amount of power generation, a bending test of the thermoelectric conversion module was conducted according to JIS K 5600. A cylindrical mandrel having a diameter of 32 mm was used and bent 180 °.
After performing the bending test, the power generation amount of the thermoelectric conversion module was measured as before.
As a result, the power generation amount was 41.8 μW.

[Comparative Example 1]
A thermoelectric conversion module was produced by producing a thermoelectric conversion element in the same manner as in Example 1 except that the silicon oxide layer was not formed on the first substrate as the first adhesion layer.
However, after forming the thermoelectric conversion layer, in many thermoelectric conversion elements, the thermoelectric conversion layer peeled off from the first substrate, and an appropriate thermoelectric conversion module could not be produced.

[Example 2]
A thermoelectric conversion module was produced in the same manner as in Example 1 except that the first adhesion layer formed on the first substrate was replaced with a chromium layer instead of the silicon oxide layer. Note that the chromium layer was formed by a sputtering method using chromium as a target.
Further, in the same manner as in Example 1, the electrical conductivity σ and Seebeck coefficient S of the thermoelectric conversion layer were measured. As a result, the conductivity σ was 42000 S / cm, and the Seebeck coefficient S was −14.7 μV / K.
Further, in the same manner as in Example 1, the power generation amount before and after the bending test of the produced thermoelectric conversion module was measured. As a result, the power generation amount before the bending test was 36.4 μW, and the power generation amount after the bending test was 34.6 μW.

[Example 3]
A thermoelectric conversion module was produced in the same manner as in Example 1 except that the thermoelectric conversion layer was replaced with an Ni90Mo10 alloy layer (Ni90 atom%, Mo10 atom% alloy layer) instead of the Ni layer. The Ni90Mo10 alloy layer was formed by a sputtering method using a Ni90Mo10 alloy as a target.
In the same manner as in Example 1, the conductivity σ and Seebeck coefficient S of the thermoelectric conversion layer were measured. As a result, the conductivity σ was 8000 S / cm, and the Seebeck coefficient S was 10 μV / K.
Further, in the same manner as in Example 1, the power generation amount before and after the bending test of the produced thermoelectric conversion module was measured. As a result, the power generation amount before the bending test was 4.19 μW, and the power generation amount after the bending test was 4.02 μW.

[Comparative Example 2]
A thermoelectric conversion element was produced by producing a thermoelectric conversion element in the same manner as in Example 3 except that the silicon oxide layer was not formed as the first adhesion layer on the first substrate.
However, after forming the thermoelectric conversion layer, in many thermoelectric conversion elements, the thermoelectric conversion layer peeled off from the first substrate, and an appropriate thermoelectric conversion module could not be produced.

[Example 4]
A thermoelectric conversion module was produced in the same manner as in Example 1 except that the electrode forming material was changed from gold to copper (Cu).
In the same manner as in Example 1, the conductivity σ and Seebeck coefficient S of the thermoelectric conversion layer were measured. As a result, the conductivity σ was 42000 S / cm, and the Seebeck coefficient S was −14.5 μV / K.
Further, in the same manner as in Example 1, the power generation amount before and after the bending test of the produced thermoelectric conversion module was measured. As a result, the power generation amount before the bending test was 53.8 μW, and the power generation amount after the bending test was 50.6 μW.

[Comparative Example 3]
A polyimide substrate (Kapton 100V, manufactured by Toray DuPont) having a size of 60 × 60 mm and a thickness of 25 μm was prepared.
By depositing a chromium film with a thickness of 100 nm by a vacuum deposition method using a metal mask, and then depositing a gold film with a thickness of 1000 nm on the chromium layer, 95 metal electrode layers were patterned on the polyimide substrate.
Next, Ni foil having a thickness of 100 μm was cut to prepare 95 Ni chips of 3 × 3 mm. The produced Ni chip was bonded onto the metal electrode layer formed on the polyimide substrate using a silver paste (FA705BN, manufactured by Fujikura Kasei Co., Ltd.).
Furthermore, by using silver paste (FA705BN, manufactured by Fujikura Kasei Co., Ltd.) as an adhesive and connecting the upper surface of the Ni chip and the metal electrode layer under the adjacent Ni chip with a copper foil having a thickness of 18 μm, uni A thermoelectric conversion module comprising 95 leg-type thermoelectric conversion elements connected in series was produced.
In the same manner as in Example 1, the conductivity σ and Seebeck coefficient S of the Ni foil were measured. As a result, the conductivity σ was 140000 S / cm and the Seebeck coefficient S was −18 μV / K.
Moreover, although the power generation amount before and after the bending test of the produced thermoelectric conversion module was measured in the same manner as in Example 1, no power generation could be measured. In Ni with high thermal conductivity, there is no temperature difference between the upper and lower sides of the thermoelectric conversion layer (between the electrodes), so it is estimated that no thermoelectromotive force occurred.

The results are shown in Table 1.

As shown in Table 1, according to the thermoelectric conversion element of the present invention, Ni or Ni alloy, which is a general-purpose material that has high heat conductivity but high power generation and high conductivity, is used in plane. By forming a thermoelectric conversion element of a mold, a high power generation amount can be obtained. In particular, Example 1 and Example 2 in which the thermoelectric conversion layer is formed of Ni obtain a high power generation amount. Moreover, the thermoelectric conversion module using the thermoelectric conversion element of the present invention has almost the same amount of power generation before and after the bending test, and is excellent in flexibility.
Furthermore, from the results of Example 4, when the electrode is made of copper, a higher power generation amount is obtained due to the excellent conductivity of copper and a slightly higher Seebeck coefficient than gold. In addition, the Seebeck coefficient of gold is 2 μV / K, and the Seebeck coefficient of copper is 4 μV / K.
On the other hand, as shown in Comparative Example 3, in the uni-leg type thermoelectric conversion element, even if the thermoelectric conversion layer is manufactured using the same Ni, there is almost no temperature difference between the upper and lower sides of the thermoelectric conversion layer, and power generation cannot be performed. It became clear. That is, it was found that a thermoelectric conversion module using the thermoelectric conversion element of the present invention is useful for using Ni or Ni alloy in the thermoelectric conversion layer.

[Example 5]
An adhesive-free double-sided copper-clad polyimide substrate (FELIOS R-F775, manufactured by Panasonic Electric Works Co., Ltd.) was prepared. The copper-clad polyimide substrate has a size of 60 × 60 mm, a polyimide layer thickness of 25 μm, and a copper layer thickness of 70 μm.
The copper on one surface of the double-sided copper-clad polyimide substrate was completely removed by etching. When the exposed polyimide surface was observed with a laser microscope (VK-X100, manufactured by Keyence Corporation), it was found that there were irregularities derived from the surface of the copper layer (copper foil).
The arithmetic average roughness Ra of the surface from which the copper layer was removed (surface where the entire surface was polyimide) was measured and found to be 0.989 μm. The arithmetic average roughness Ra was measured according to JIS B 0601 (2001) by measuring the height of the surface using a shape measurement laser microscope: VK-X200 (manufactured by Keyence Corporation). . At this time, the observation range was set to 1.405 mm in width and 1.05 mm in length. From this observation range, three lines were extracted in the horizontal direction, the arithmetic average roughness Ra was determined, and the average value was calculated.

Further, the remaining copper layer of the copper-clad polyimide substrate from which the copper layer on one side is removed is etched to form a copper stripe pattern having a width of 500 μm and an interval of 500 μm, and FIG. 2 (A), FIG. 2 (C) and A first substrate and a second substrate as shown in FIG.

A silicon oxide layer (SiO ₂ layer) having a thickness of 200 nm was formed as a first adhesion layer on the entire surface of the first substrate which is a polyimide layer by EB vapor deposition. The surface on which the entire surface of the first substrate is a polyimide layer is the planar surface of the first substrate.
Next, a thermoelectric conversion layer made of Ni having a thickness of 1 μm was formed by a sputtering method using a Ni target. Note that the thermoelectric conversion layer was formed using a metal mask at an equal interval of 1770 (59 × 30) patterns of 500 × 1000 μm as conceptually shown in FIG.

Next, a laminated electrode made of 0.05 μm thick chromium (Cr) and 2 μm thick gold (Au) is fabricated by vacuum vapor deposition using a metal mask, as conceptually shown in FIG. In addition, 1770 thermoelectric conversion layers were connected in series.

The conductivity σ and Seebeck coefficient S of the thermoelectric conversion layer were measured in the same manner as in Example 1 except that the thermoelectric conversion layer was formed on the surface of the copper-clad polyimide substrate from which the copper foil was removed.
As a result, the conductivity σ was 46500 S / cm and the Seebeck coefficient S was −15.4 μV / K.
Further, in the same manner as in Example 1, the power generation amount before and after the bending test of the produced thermoelectric conversion module was measured. As a result, the power generation amount before the bending test was 43.4 μW, and the power generation amount after the bending test was 42.1 μW.

[Example 6]
A thermoelectric conversion module was produced in the same manner as in Example 5 except that the first adhesion layer formed on the first substrate was replaced with a chromium layer instead of the silicon oxide layer. Note that the chromium layer was formed by a sputtering method using chromium as a target.
Further, in the same manner as in Example 5, the conductivity σ and Seebeck coefficient S of the thermoelectric conversion layer were measured. As a result, the conductivity σ was 42000 S / cm, and the Seebeck coefficient S was −14.7 μV / K.
Further, in the same manner as in Example 1, the power generation amount before and after the bending test of the produced thermoelectric conversion module was measured. As a result, the power generation amount before the bending test was 36.4 μW, and the power generation amount after the bending test was 35.2 μW.

[Example 7]
A thermoelectric conversion module was produced in the same manner as in Example 5 except that the thermoelectric conversion layer was replaced with an Ni90Mo10 alloy layer (Ni90 atom%, Mo10 atom% alloy layer) instead of the Ni layer. The Ni90Mo10 alloy layer was formed by a sputtering method using a Ni90Mo10 alloy as a target.
In the same manner as in Example 5, the conductivity σ and Seebeck coefficient S of the thermoelectric conversion layer were measured. As a result, the conductivity σ was 8000 S / cm, and the Seebeck coefficient S was 10 μV / K.
Further, in the same manner as in Example 1, the power generation amount before and after the bending test of the produced thermoelectric conversion module was measured. As a result, the power generation amount before the bending test was 4.19 μW, and the power generation amount after the bending test was 4.07 μW.

[Example 8]
A thermoelectric conversion module was prepared in the same manner as in Example 5 except that the electrode was changed from a laminated electrode made of chromium and gold to a laminated electrode made of 0.05 μm thick chromium and 0.5 μm thick copper. Produced.
In the same manner as in Example 5, the conductivity σ and Seebeck coefficient S of the thermoelectric conversion layer were measured. As a result, the conductivity σ was 42000 S / cm, and the Seebeck coefficient S was −14.7 μV / K.
Further, in the same manner as in Example 1, the power generation amount before and after the bending test of the produced thermoelectric conversion module was measured. As a result, the power generation amount before the bending test was 45.2 μW, and the power generation amount after the bending test was 43.4 μW.

[Example 9]
The first adhesion layer formed on the first substrate is a chromium layer instead of the silicon oxide layer, and the electrode is a laminated electrode made of chromium and gold, and has a thickness of 0.05 μm and a thickness of 0.5 μm. A thermoelectric conversion module was produced in the same manner as in Example 5 except that the laminated electrode was made of copper.
In the same manner as in Example 5, the conductivity σ and Seebeck coefficient S of the thermoelectric conversion layer were measured. As a result, the conductivity σ was 42000 S / cm, and the Seebeck coefficient S was −14.7 μV / K.
Further, in the same manner as in Example 1, the power generation amount before and after the bending test of the produced thermoelectric conversion module was measured. As a result, the power generation amount before the bending test was 38.2 μW, and the power generation amount after the bending test was 37.1 μW.

[Example 10]
A first substrate was produced in the same manner as in Example 5 except that the copper beats on one surface of the double-sided copper-clad polyimide substrate were removed, and then this surface was subjected to a roughening treatment by sandblasting.
The sand blasting was performed with a sand blasting apparatus (SCM-4RBY-05-401, manufactured by Fuji Seisakusho Co., Ltd.) using φ20 μm alumina particles at a supply air pressure of 0.1 MPa. When the arithmetic average roughness Ra of the surface subjected to the roughening treatment was measured in the same manner as in Example 5, the arithmetic average roughness Ra was 1.68 μm.
A thermoelectric conversion module was produced in the same manner as in Example 9 except that this first substrate was used.
In the same manner as in Example 5, the conductivity σ and Seebeck coefficient S of the thermoelectric conversion layer were measured. As a result, the conductivity σ was 46500 S / cm and the Seebeck coefficient S was −15.4 μV / K.
Further, in the same manner as in Example 1, the power generation amount before and after the bending test of the produced thermoelectric conversion module was measured. As a result, the power generation amount before the bending test was 43.4 μW, and the power generation amount after the bending test was 42.6 μW.

[Example 11]
A first substrate was produced in the same manner as in Example 10.
A thermoelectric conversion module was produced in the same manner as in Example 8 except that this first substrate was used.
In the same manner as in Example 5, the conductivity σ and Seebeck coefficient S of the thermoelectric conversion layer were measured. As a result, the conductivity σ was 42000 S / cm, and the Seebeck coefficient S was −14.7 μV / K.
Further, in the same manner as in Example 1, the power generation amount before and after the bending test of the produced thermoelectric conversion module was measured. As a result, the power generation amount before the bending test was 45.2 μW, and the power generation amount after the bending test was 44.3 μW.

The results are shown in Table 2 below.

As shown in Table 2, a highly flexible thermoelectric conversion module is obtained by roughening the formation surface of the first adhesion layer of the first substrate.
In particular, as shown in Example 10 and Example 11, by increasing the surface roughness of the surface of the first substrate on which the first adhesion layer is formed, the amount of power generation is almost unchanged before and after the bending test. A thermoelectric conversion module having excellent flexibility can be obtained.

[Example 12]
The thermoelectric conversion module produced by the method similar to Example 11 was adhere | attached on the curved surface ((phi) 120mm) -shaped heating source (surface temperature of 80 degreeC) using the heat conductive adhesive sheet (TR5912F, Nitto Denko Corporation make).
Further, a corrugated fin (COA-5B2D75B, size 100 × 100 mm, manufactured by Mogami Inc.) was bonded to the surface of the thermoelectric conversion module using a heat conductive adhesive sheet (TR5912F, manufactured by Nitto Denko Corporation).
Connect the electrode of the most upstream thermoelectric conversion element and the electrode of the most downstream thermoelectric conversion element connected in series to the source meter (source meter 2450, manufactured by Keithley) and measure the open-circuit voltage and short-circuit current, and the amount of power generation Was obtained, and an output of 2.7 μW was obtained.
From this result, it can be seen that the heat conversion module of the present invention can generate power even with air cooling, and can generate power even with a curved heat source.
From the above results, the effects of the present invention are clear.

DESCRIPTION OF SYMBOLS 10

Thermoelectric conversion element

12, 12A 1st board |

substrate

12a, 20a Low

heat conduction part

12b, 20b High heat conduction part 14 1st adhesion layer 16 Thermoelectric conversion layer 18

2nd adhesion layer

20, 20A 2nd board |

substrate

26, 28 Electrode

Claims

A first substrate having a high thermal conductivity part having a higher thermal conductivity than other regions in at least a part of the surface direction;
A first adhesion layer formed on the first substrate;
A thermoelectric conversion layer made of nickel or a nickel alloy formed on the first adhesion layer;
A second adhesion layer formed on the thermoelectric conversion layer;
The high adhesion portion formed on the second adhesion layer has a high thermal conductivity higher than that of another region in at least a part of the surface direction, and the high heat conduction portion of the surface in the surface direction includes the first heat conduction portion. A second substrate that does not completely overlap the high thermal conductivity portion of one substrate;
A thermoelectric conversion element comprising a pair of electrodes connected to the thermoelectric conversion layer so as to sandwich the thermoelectric conversion layer in a plane direction.
The thermoelectric conversion element according to claim 1, wherein the nickel content of the thermoelectric conversion layer is 90 atomic% or more.
The thermoelectric conversion element according to claim 2, wherein the thermoelectric conversion layer is formed of nickel.
The thermoelectric conversion according to any one of claims 1 to 3, wherein the high thermal conductivity portion of the first substrate and the high thermal conductivity portion of the second substrate are provided at different positions in the plane direction in the separation direction of the electrodes. element.
The thermoelectric conversion element according to any one of claims 1 to 4, wherein the high thermal conductivity portion of the first substrate and the high thermal conductivity portion of the second substrate are located on an outer surface with respect to the stacking direction.
The thermoelectric conversion element according to any one of claims 1 to 5, wherein a surface of the first substrate on the first adhesion layer side is subjected to a roughening treatment.
The thermoelectric conversion element according to claim 6, wherein the arithmetic average roughness Ra of the surface of the first substrate on the first adhesion layer side is 0.9 µm or more.
A thermoelectric conversion module comprising a plurality of the thermoelectric conversion elements according to any one of claims 1 to 7 connected in series.
The thermoelectric conversion module according to claim 8, further comprising heat radiation fins in contact with either one of the first substrate and the second substrate.
The thermoelectric conversion module according to claim 9, wherein the heat radiation fin and the high heat conductive portion are bonded with a heat conductive adhesive sheet or a thermoconductive adhesive.
Forming a first adhesion layer on a first substrate having a high thermal conductivity portion having a higher thermal conductivity than other regions in at least part of the surface direction;
Forming a thermoelectric conversion layer made of nickel or a nickel alloy on the first adhesion layer;
Connecting the electrode pair to the thermoelectric conversion layer so as to be sandwiched in the surface direction;
Forming a second adhesion layer on the thermoelectric conversion layer;
And on the second adhesion layer, at least part of the surface direction has a high heat conduction part having a higher heat conductivity than other regions, and the high heat conduction part of itself in the surface direction And a step of laminating the second substrate so as not to completely overlap with the high thermal conductivity portion of the first substrate.
The method of manufacturing a thermoelectric conversion element according to claim 11, wherein the thermoelectric conversion layer is formed by a vapor deposition method.
The method for manufacturing a thermoelectric conversion element according to claim 11 or 12, wherein a surface roughening treatment is performed on a formation surface of the first adhesion layer of the first substrate prior to the formation of the first adhesion layer.
The method for manufacturing a thermoelectric conversion element according to claim 13, wherein the roughening treatment is performed so that an arithmetic average roughness Ra of a surface of the first adhesion layer of the first substrate is 0.9 µm or more.