Thermoelectric module and thermoelectric system

Abstract

To improve heat dissipation compared to conventional thermoelectric modules.SOLUTION: A thermoelectric module (10) includes a substrate (11), a plurality of fins (12) protruding from a first region (main surface 111) and covered with an insulating layer (13), and a single-walled carbon nanotube layer (SWCNT layer 14) superimposed on the insulating layer (13) in a section (S).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a thermoelectric module and a thermoelectric system. [Background technology]

[0002] Patent Document 1 describes a thermoelectric module including a plurality of p-type thermoelectric elements and a plurality of n-type thermoelectric elements, in which the p-type thermoelectric elements and the n-type thermoelectric elements are arranged alternately, and adjacent first and second thermoelectric elements are connected by electrodes (see FIGS. 2 to 5 of Patent Document 1). Such a thermoelectric module is capable of generating electricity by utilizing the Seebeck effect, and is therefore applied to power generation devices and the like.

[0003] In this thermoelectric module, the electrodes connecting the p-type thermoelectric elements and the n-type thermoelectric elements are given the function of a heat sink, thereby improving the heat dissipation performance of the thermoelectric module. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2016-092017 Summary of the Invention [Problem to be solved by the invention]

[0005] Incidentally, the materials used for the p-type and n-type thermoelectric elements in the thermoelectric module described in Patent Document 1 have lower thermal conductivities than metals (e.g., aluminum, copper, and alloys containing these metals) commonly used as heat sink materials. Therefore, even if the electrodes connecting the p-type and n-type thermoelectric elements in the thermoelectric module are given the function of a heat sink, it is difficult to efficiently remove heat from the electrodes. This is because the p-type and n-type thermoelectric elements are interposed between the electrode in contact with the heat source and the electrode functioning as a heat sink, hindering heat conduction from the heat source to the electrode functioning as a heat sink.

[0006] One aspect of the present invention has been made in view of the above-mentioned problems, and its object is to improve heat dissipation compared to conventional thermoelectric modules (described in Patent Document 1). [Means for solving the problem]

[0007] In order to solve the above problems, a thermoelectric module according to one embodiment of the present invention comprises a substrate, a plurality of fins protruding from the surface of the substrate, the fins being made of metal or semiconductor, and at least a portion of the section from the base to the tip being covered with an insulating layer, a single-walled carbon nanotube (SWCNT) layer provided on top of the insulating layer within the portion, and a first wiring connecting the SWCNT layers of the first fin and the second fin, when one of the plurality of fins is defined as a first fin and two fins adjacent to the first fin are defined as a second fin and a third fin, respectively, and a second wiring connecting the SWCNT layers of the first fin and the third fin.

[0008] In addition, in order to solve the above-mentioned problems, a thermoelectric module according to one embodiment of the present invention includes a substrate, a plurality of fins protruding from a first region of the substrate, the fins being made of fine ceramics, a single-walled carbon nanotube (SWCNT) layer covering each fin in at least a portion of the section from the base to the tip of each fin, and a first wiring connecting the SWCNT layers of the first fin and the second fin, when one of the plurality of fins is defined as a first fin and two fins adjacent to the first fin are defined as a second fin and a third fin, respectively, and a second wiring connecting the SWCNT layers of the first fin and the third fin.

[0009] The scope of the present invention also includes a thermoelectric system comprising a thermoelectric module according to one embodiment of the present invention and a heat source that generates heat during operation, wherein the heat source is disposed in a second region of the substrate that is different from the first region and in which the fins are not formed. [Effects of the Invention]

[0010] According to one aspect of the present invention, heat dissipation can be improved compared to conventional thermoelectric modules. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a schematic cross-sectional view of a thermoelectric module according to a first embodiment of the present invention. [Figure 2] FIG. 4 is a schematic cross-sectional view of a thermoelectric module according to a second embodiment of the present invention. [Figure 3] FIG. 10 is a schematic cross-sectional view of a thermoelectric module according to a third embodiment of the present invention. [Figure 4] 4 is a graph showing the time dependence of the temperature obtained when a thermoelectric module according to a comparative example of the present invention is heated. In Fig. 4, the temperatures at the base and tip of the fins are shown by thick and thin lines, respectively. [Figure 5]5 is a graph showing the time dependence of the temperature obtained when heating the thermoelectric module according to Example 1 of the present invention. In Fig. 5, the temperatures at the base and tip of the fin are shown by thick and thin lines, respectively. [Figure 6] 6 is a graph showing the temperature difference between the base and tip of the fin as a function of time, which is obtained in each of the thermoelectric modules according to Example 1 of the present invention and the comparative example. In Fig. 6, Example 1 and the comparative example are shown by thick and thin lines, respectively. [Figure 7] 4 is a graph showing the elapsed time dependency of the output voltage obtained in the thermoelectric module according to Example 1 of the present invention. [Figure 8] 4 is a graph showing the temperature difference dependency of the output voltage obtained in the thermoelectric module according to Example 1 of the present invention. [Figure 9] 10 is a graph showing the temperature difference dependency of the output voltage obtained in the thermoelectric module according to Example 2 of the present invention. [Figure 10] 10 is a graph showing the temperature difference dependency of the output voltage obtained in the thermoelectric module according to Example 3 of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0012] [Embodiment 1] A thermoelectric module 10 according to a first embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is a schematic cross-sectional view of the thermoelectric module 10. The cross-sectional view of Fig. 1 is a cross-sectional view obtained by taking a cross section passing through the centers of a plurality of fins 12, which will be described later. The thermoelectric module 10 can generate electricity by utilizing the Seebeck effect, similar to the thermoelectric module described in Patent Document 1.

[0013] <Thermoelectric module configuration> As shown in Fig. 1, a thermoelectric module 10 includes a substrate 11, a plurality of fins 12, an insulating layer 13, an SWCNT layer 14, wiring 15, and an adhesive 16. Note that Fig. 1 illustrates only the configurations of the plurality of fins 12, the insulating layer 13, the SWCNT layer 14, and the wiring 15 where n = i-1, i, and i+1, and omits the configurations of n = i-2, i+2, and i+3. The meaning of n will be explained later. SWCNT is an abbreviation for single-walled carbon nanotube.

[0014] (Base) The substrate 11 is a block made of metal, semiconductor, or fine ceramic. In this embodiment, as shown in FIG. 1 , the substrate 11 has a rectangular parallelepiped shape having a pair of main surfaces 111 and 112 and four side surfaces intersecting the main surfaces 111 and 112. The main surface 111 is an example of a first region on the surface of the substrate 11 where a plurality of fins 12 (described later) are provided. The main surface 112 is an example of a second region on the surface of the substrate 11 where a heat source (described later) is brought into contact. The substrate 11 shown in FIG. 1 can also be called a plate or a block. However, the shape of the substrate 11 is not limited to a plate shape and can be determined appropriately. Examples of heat sources that can be brought into contact with the main surface 112 include electronic components such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), and an SSD (Solid State Drive, an example of an auxiliary storage device). However, the heat source is not particularly limited as long as it has a temperature higher than the surrounding environment, and can be selected appropriately. Examples of heat sources other than electronic components include hot water pipes, steam pipes, and exhaust gas pipes. Also included within the scope of the present invention is a thermoelectric system including a thermoelectric module 10 and a heat source, in which the heat source is disposed on a main surface 112 (second region) different from the main surface 111 (first region) of the substrate 11. The main surface 112 is an example of the second region where the multiple fins 12 are not formed.

[0015] Although the metal, semiconductor, or fine ceramic constituting the substrate 11 is not particularly limited, it is preferable that it has a thermal conductivity exceeding 10 W / m°C. The material constituting the substrate 11 is preferably a material that exhibits good thermal conductivity. Furthermore, when the substrate 11 is made of a metal, preferred metals include aluminum and copper. The metal constituting the substrate 11 may also be an alloy containing at least one of aluminum and copper. An example of such an alloy is tungsten copper (CuW). In this embodiment, the substrate 11 is made of aluminum. Furthermore, when the substrate 11 is made of a semiconductor, preferred semiconductors include silicon. Furthermore, when the substrate 11 is made of fine ceramics, preferred fine ceramics include aluminum nitride, silicon carbide, aluminum oxide (alumina), and silicon nitride.

[0016] 1, the main surface 111 and the main surface 112 are flat surfaces parallel to each other. However, in one embodiment of the present invention, the main surface 111 and the main surface 112 do not have to be parallel, and may be curved surfaces or surfaces having irregularities. In particular, the main surface 112 is the surface that comes into contact with a heat source, which is an object to be cooled using the thermoelectric module 10. Therefore, it is preferable that the shape of the main surface 112 corresponds to the shape of the surface of the heat source so as to ensure good contact with the surface of the heat source.

[0017] 1, (1) the direction perpendicular to main surface 111 and main surface 112 is defined as the Z-axis direction, the direction in which multiple fins 12 are arranged on main surface 111 is defined as the X-axis direction, and the direction perpendicular to the X-axis within the plane of main surface 111 is defined as the Y-axis direction. Furthermore, within the Z-axis direction, the direction from main surface 112 to main surface 111 is defined as the Z-axis positive direction, and the direction from left to right in FIG. 1 is defined as the X-axis positive direction. The Y-axis positive direction is defined so as to define a right-handed Cartesian coordinate system together with the X-axis positive direction and the Z-axis positive direction. In FIG. 1, the Y-axis positive direction is the direction from the front to the back.

[0018] (fin) The fins 12 are heat dissipation members protruding from the main surface 111 and are made of metal, semiconductor, or fine ceramics. By protruding from the main surface 111, the fins 12 increase the surface area and improve heat dissipation efficiency. The shape of the fins 12 is not limited, but examples include columnar and plate shapes. In this embodiment, each fin 12 is a cylindrical member with a pair of circular bottom surfaces. Note that columnar fins 12 are also called pin fins.

[0019] Furthermore, in order to increase the surface area, the surface of each fin 12 may be formed with projections and recesses. The projections and recesses may have a spiral structure similar to that formed on the surface of a screw or bolt.

[0020] The material (metal, semiconductor, or fine ceramic) constituting each fin 12 is the same as the material constituting the above-described base material 11. Therefore, here, a description of the material constituting the plurality of fins 12 will be omitted. In this embodiment, the plurality of fins 12 are made of aluminum.

[0021] Although not shown in the drawings, in this embodiment, the fins 12 are arranged on the main surface 111 in a matrix (or lattice) of n rows and m columns. Here, n and m are each any integer equal to or greater than 2. In addition, in FIG. 1, the arrangement of the fins 12 in a certain column is expressed as n=i-2, i-1, i, i+1, i+2, i+3, where i is the number of fins 12. Note that in one aspect of the present invention, there is no upper limit to the total number of fins 12 (n×m in this embodiment). Furthermore, there is no limit to the way in which the fins 12 are arranged on the main surface 111, and they may be regular (or periodic) or irregular.

[0022] (insulating layer) The insulating layer 13 is formed on at least a portion of the section from the base to the tip of each fin 12. The insulating layer 13 is used when a metal or a semiconductor is used as the material for each fin 12. On the other hand, when fine ceramics are used as the material for each fin 12, the insulating layer 13 can be omitted. This is because fine ceramics are inherently insulators. In this embodiment, a natural oxide film naturally formed on the surface of the aluminum constituting each fin 12 is used as the insulating layer 13. Therefore, in this embodiment, the insulating layer 13 is formed on the entire section from the base to the tip of each fin 12, covering both the end face on the base side (negative side of the Z-axis) and the end face on the tip side (positive side of the Z-axis). However, as described above, it is sufficient that the insulating layer 13 is formed on at least a portion of the section from the base to the tip of each fin 12. Therefore, the insulating layer 13 may not be formed on part of the fin 12, such as the end face on the base side or the end face on the tip side. When silicon, which is an example of a semiconductor, is used as the material forming each of the fins 12, the insulating layer 13 may be formed by oxidizing the surface of the silicon.

[0023] Note that the method for forming an oxide film as the insulating layer 13 on the surface of each fin 12 is not limited to natural oxidation. For example, the surface of each fin 12 can also be oxidized using existing oxidation techniques such as plasma oxidation or anodic oxidation. Alternatively, the insulating layer 13 can be formed by depositing an oxide film on the surface of each fin 12.

[0024] (SWCNT layer) The SWCNT layer 14 is a layer provided on the surface of each fin 12 so as to overlap the insulating layer 13, and is a layer formed by depositing single-walled carbon nanotubes (SWCNTs).

[0025] SWCNTs can be classified into semiconducting carbon nanotubes (S-SWCNTs) that have semiconducting conductive properties, and metallic carbon nanotubes (M-SWCNTs) that have metallic conductive properties. To construct a thermoelectric device, a material that exhibits the Seebeck effect is required, so S-SWCNTs are used as the SWCNTs that make up the SWCNT layer 14.

[0026] S-SWCNTs can be classified into p-type carbon nanotubes (p-SWCNTs), which are p-type semiconductors, and n-type carbon nanotubes (n-SWCNTs), which are n-type semiconductors. In this embodiment, either p-SWCNTs or n-SWCNTs (here, p-SWCNTs) are used as the S-SWCNTs that make up the SWCNT layer 14.

[0027] However, n-SWCNTs may also be used as the S-SWCNTs that make up the SWCNT layer 14, or different types of p-SWCNTs and n-SWCNTs may be used in combination, as will be described later with reference to Figures 2 and 3.

[0028] In this embodiment, the SWCNT layer 14 is provided in a section S (see FIG. 1 ) of the section where the insulating layer 13 is provided, excluding the vicinity of the end face on the base side of each fin 12. That is, the SWCNT layer 14 covers the tip (end face on the tip side) of each fin 12. However, in one aspect of the present invention, the SWCNT layer 14 does not have to be formed at the tip or the vicinity of the tip. That is, the insulating layer 13 may be exposed from the SWCNT layer 14 at the tip or the vicinity of the tip.

[0029] On the other hand, it is preferable not to provide the SWCNT layer 14 on the end surface on the base side of each fin 12. This is because the SWCNT layers 14 provided on each fin 12 would be short-circuited to each other.

[0030] (wiring) Any one of the multiple fins 12 (here, as an example, the fin 12 with n=i) is defined as the first fin, and the two fins adjacent to the fin 12 with n=i (here, the fins 12 with n=i-1, i+1) are defined as the second fin and the third fin.

[0031] As shown in FIG. 1 , wiring 15 connects the vicinity of the lower end of the SWCNT layer 14 of fin 12, which is the first fin, to the vicinity of the upper end of the SWCNT layer 14 of fin 12, which is the second fin. This wiring 15 is an example of a first wiring. Another wiring 15 connects the vicinity of the upper end of the SWCNT layer 14 of fin 12, which is the first fin, to the vicinity of the lower end of the SWCNT layer 14 of fin 12, which is the third fin. This wiring 15 is an example of a second wiring. In this way, by defining the second fin, third fin, first wiring, and second wiring with fin 12 where n=i as the first fin, and then changing i in each column within the range of 2≦i≦n−1, a thermoelectric module 10 having an arbitrary number of fins 12 (n×m in this embodiment) can be designed. Furthermore, when the total number of fins 12 (n×m in this embodiment) is a multiple of 3, the thermoelectric module 10 may be designed by connecting a plurality of unit structures, each consisting of three fins 12, the first to third fins. Note that FIG. 1 illustrates a case where the first to third fins are located in the same row. However, the first to third fins may be located across different rows.

[0032] In the thermoelectric module 10 configured in this manner, a plurality of (n×m in this embodiment) SWCNT layers 14 provided on each of a plurality of (n×m in this embodiment) fins 12 are connected in series using wiring 15 that functions as a first wiring and wiring 15 that functions as a second wiring. In addition, although not shown in FIG. 1 , the thermoelectric module 10 further includes output terminals provided on both ends of the plurality of series-connected SWCNT layers 14. That is, one terminal constituting the output terminal is connected to the first SWCNT layer 14 (the first SWCNT layer 14) of the plurality of series-connected SWCNT layers 14, and the other terminal constituting the output terminal is connected to the last SWCNT layer 14 (the n×mth SWCNT layer 14) of the plurality of series-connected SWCNT layers 14.

[0033] (glue) As described above, the multiple fins 12 are fixed to the main surface 111 so as to protrude from the main surface 111. In this embodiment, adhesive 16 is used as a fixing means for fixing each fin 12 to the main surface 111 in an upright state.

[0034] The type of adhesive 16 is not limited as long as it can bond the metal or metal oxide constituting the main surface 111 to the insulating layer 13 covering the surface of each fin 12. However, since the adhesive 16 is interposed between the substrate 11 and each fin 12, it is preferable that the adhesive be an adhesive that exhibits good thermal conductivity so as to minimize the inhibition of thermal conduction between the substrate 11 and each fin 12. Examples of such adhesives include conductive adhesives such as silver paste, heat dissipation grease, and carbon paste.

[0035] The conductive adhesive not only exhibits good thermal conductivity, but also has electrical conductivity, as its name suggests. Therefore, when using a conductive adhesive as adhesive 16, it is preferable to separate SWCNT layer 14 from adhesive 16 to prevent short-circuiting between SWCNT layer 14 and substrate 11.

[0036] The means for fixing each fin 12 to the main surface 111 of the base material 11 is not limited to adhesive. For example, as in thermoelectric module 20 shown in Fig. 2, holes may be formed in the main surface 111 and the base of each fin 12 may be inserted into the holes. Furthermore, as in thermoelectric module 30 shown in Fig. 3, the base material 11 and the multiple fins 12 may be integrally formed by cutting them out from a single block of metal.

[0037] (Thermoelectric module output due to temperature difference) In the thermoelectric module 10 configured as described above, a heat source is brought into contact with the main surface 112 of the substrate 11. As a result, when viewed along the Z-axis direction in FIG. 1, the temperature T1 at the base of each fin 12 in contact with the substrate 11 is high, and the temperature T2 at the tip is low. Therefore, a temperature difference ΔT (= T1 - T2) occurs between the base and tip of each fin 12. The SWCNTs constituting the SWCNT layer 14 provided on each fin 12 exhibit the Seebeck effect. Therefore, the SWCNT layer 14 provided on each fin 12 generates electricity according to the temperature difference ΔT. In the thermoelectric module 10, three fins 12 (first to third fins) are used as a unit configuration, and the SWCNT layers 14 provided on each of the first to third fins 12 are connected in series by wiring 15, which are the first and second wirings. Therefore, a voltage difference occurs between both ends of the n × m fins 12 constituting the thermoelectric module 10 (i.e., the two terminals constituting the output terminals). In the embodiments described below, this voltage difference occurring in response to the temperature difference ΔT is referred to as the output voltage of the thermoelectric module 10. If the six fins 12 shown in FIG. 1 are used instead of the n×m fins 12, the voltage difference occurring across the six fins 12 means the voltage difference occurring between the wiring 15 extending leftward from the fin 12 where n=i−2 and the wiring 15 extending rightward from the fin 12 where n=i+3.

[0038] [Embodiment 2] A thermoelectric module 20 according to a second embodiment of the present invention will be described with reference to Fig. 2. Fig. 2 is a schematic cross-sectional view of the thermoelectric module 20.

[0039] The thermoelectric module 20 can be considered a modified example of the thermoelectric module 10 according to embodiment 1. Therefore, for the sake of convenience, the same reference numerals are used to designate members having the same functions as those described in embodiment 1, and the description thereof will not be repeated.

[0040] 2, the thermoelectric module 20 includes a base material 21, a plurality of fins 12, an insulating layer 13, an SWCNT layer 14, and wiring 25. Note that in Fig. 2, for each of the reference symbols for the plurality of fins 12, the insulating layer 13, the SWCNT layer 24, and the wiring 25, only the configurations where n = i-1, i, and i+1 are shown, and the configurations where n = i-2, i+2, and i+3 are not shown.

[0041] Similar to the substrate 11 shown in FIG. 1 , the substrate 21 is a plate-like member made of metal (here, aluminum), and has a pair of main surfaces 211 and 212. The main surfaces 211 and 212 correspond to the main surfaces 111 and 112, respectively. However, the main surface 212 has holes formed in a matrix (or lattice) of n rows and m columns at positions where the fins 12 are fixed. The diameters of these holes correspond to the diameter of the bottom surface of each cylindrical fin 12. Therefore, each fin 12 can be fixed to the main surface 211 by inserting the base of each fin 12 into the hole formed in the main surface 211.

[0042] In this embodiment, each fin 12 is fixed to the main surface 211 by press-fitting the base into each hole. However, the means (or method) for fixing each fin 12 to the main surface 211 is not limited to this. For example, each fin 12 can also be fixed to the main surface 211 using adhesive 16 shown in FIG. 1.

[0043] In addition, in the thermoelectric module 20, the insulating layer 13 is formed over the entire section from the base to the tip of each fin 12, covering both the end face on the base side (negative Z-axis direction side) and the end face on the tip side (positive Z-axis direction side). In this respect, the thermoelectric module 20 has the same configuration as the thermoelectric module 10.

[0044] Furthermore, the section S in which the SWCNT layer 24 is provided in each fin 12 of the thermoelectric module 20 is the same as the section S in which the SWCNT layer 14 is provided in each fin 12 of the thermoelectric module 10 (see FIG. 2). That is, the tip of each fin 12 of the thermoelectric module 20 is covered with the insulating layer 13 and the SWCNT layer 24.

[0045] In the thermoelectric module 20, the SWCNT layer 24 provided on each fin 12 is composed of p-type or n-type S-SWCNTs that exhibit semiconducting conductive properties, and the SWCNT layers 24 of two adjacent fins 12 among the multiple fins 12 are composed of different types of p-type and n-type S-SWCNT layers. In Figure 2, the S-SWCNTs where n = i-2, i, and i+2 are composed of p-SWCNTs, and the S-SWCNTs where n = i-1, i+1, and i+3 are composed of n-SWCNTs. Note that in Figure 2, the types of S-SWCNTs that make up the SWCNT layer 24 are distinguished by varying the spacing between the hatches.

[0046] In the thermoelectric module 20, as in the thermoelectric module 10, one of the multiple fins 12 (here, as an example, the fin 12 where n=i) is defined as the first fin, and the two fins adjacent to the fin 12 where n=i (here, the fins 12 where n=i-1, i+1) are defined as the second fin and the third fin.

[0047] The wiring 25 corresponds to the wiring 15 of the thermoelectric module 10. As shown in FIG. 2, the wiring 25 connects the vicinity of the lower end of the SWCNT layer 24 of the fin 12, which is the first fin, to the vicinity of the upper end of the SWCNT layer 24 of the fin 12, which is the second fin. This wiring 25 is an example of a first wiring. Another wiring 25 connects the vicinity of the upper end of the SWCNT layer 24 of the fin 12, which is the first fin, to the vicinity of the lower end of the SWCNT layer 14 of the fin 12, which is the third fin. This other wiring 25 is an example of a second wiring.

[0048] In the thermoelectric module 20 configured in this manner, SWCNT layers 24 made of p-SWCNTs and SWCNT layers 24 made of n-SWCNTs are arranged alternately, and the SWCNT layers 24 are connected in series using wiring 25. Therefore, it can be said that the multiple SWCNT layers 24 in the thermoelectric module 20 form a pn junction.

[0049] [Embodiment 3] A thermoelectric module 30 according to a third embodiment of the present invention will be described with reference to Fig. 3. Fig. 3 is a schematic cross-sectional view of the thermoelectric module 30.

[0050] The thermoelectric module 30 can be considered a modified example of the thermoelectric module 10 according to the embodiment 1, and can also be considered a modified example of the thermoelectric module 20 according to the embodiment 2. Therefore, for the sake of convenience, the same reference numerals are used to designate members having the same functions as the members described in the embodiments 1 and 2, and the description thereof will not be repeated.

[0051] 3, the thermoelectric module 30 includes a base material 31, a plurality of fins 32, an insulating layer 33, an SWCNT layer 34, and wiring 35. Note that in FIG. 3, for each of the reference symbols for the plurality of fins 32, the insulating layer 33, the SWCNT layer 34, and the wiring 35, only the configurations where n=i-1, i, and i+1 are shown, and the configurations where n=i-2, i+2, and i+3 are not shown.

[0052] In the thermoelectric module 30, a base material 31 and a plurality of fins 32 are integrally formed. The plurality of fins 32 are arranged on the base material 31, out of a pair of main surfaces 311 and 312, in a matrix (or lattice) of n rows and m columns.

[0053] The base material 31 and the plurality of fins 32 are made of metal (aluminum in this example) like the base material 11 and the base material 21. The integrally molded base material 31 and the plurality of fins 32 can be produced by cutting out from a metal block, can be produced as a casting, or can be produced using a 3D printer.

[0054] In the thermoelectric module 30, the insulating layer 33 is formed in an area of ​​the main surface 311 where the fins 32 are not formed and in the entire section from the base to the tip of each fin 32. That is, the insulating layer 33 covers the entire surface of the thermoelectric module 30 on which the fins 32 are provided. Therefore, the tip of each fin 32 is covered with the insulating layer 33.

[0055] In this embodiment, the insulating layer 33 is formed by performing plasma oxidation on the surfaces of the aluminum that constitutes the base material 31 and each of the fins 32. However, the method for forming the insulating layer 33 is not limited to plasma oxidation.

[0056] In the thermoelectric module 30, the SWCNT layer 34 is provided on the entire section S of each fin 32 and on the tip of each fin 32 (see FIG. 3). In this manner, the tip of each fin 32 is covered with the insulating layer 33 and the SWCNT layer 34.

[0057] In the thermoelectric module 30, the SWCNT layer 34 provided on each fin 32 is composed of p-type and n-type S-SWCNTs (p-SWCNTs and n-SWCNTs), respectively, which exhibit semiconducting conductive properties.

[0058] Specifically, as shown in FIG. 3, the section S of each fin 32 is divided into two sections, with the section closest to the base being the first section S1 and the section closest to the tip being the second section S2. The first section S1 and the second section S2 are adjacent to each other. The first SWCNT layer 341 provided in the first section S1 is composed of one of p-type and n-type S-SWCNTs (p-SWCNTs in this embodiment) that exhibit semiconducting conductive properties, and the second SWCNT layer 342 provided in the second section S2 is composed of the other of the p-type and n-type S-SWCNTs (n-SWCNTs in this embodiment). In FIG. 3, the p-SWCNTs and n-SWCNTs are distinguished by varying the spacing between the hatching.

[0059] The first SWCNT layer 341 provided in the first section S1 and the second SWCNT layer 342 provided in the second section S2 are electrically connected. The first SWCNT layer 341 and the second SWCNT layer 342 may overlap near the boundary between the first section S1 and the second section S2. Therefore, each of the multiple SWCNT layers 34 in the thermoelectric module 30 can be said to form a pn junction.

[0060] In the thermoelectric module 30, as in the thermoelectric modules 10 and 20, one of the multiple fins 32 (here, as an example, the fin 32 where n=i) is defined as the first fin, and the two fins adjacent to the fin 32 where n=i (here, the fins 32 where n=i-1, i+1) are defined as the second fin and the third fin, respectively.

[0061] The wiring 35 corresponds to the wiring 15 of the thermoelectric module 10. As shown in FIG. 3, the wiring 25 connects the vicinity of the lower end of the SWCNT layer 34 of the fin 32, which is the first fin, to the vicinity of the upper end of the SWCNT layer 34 of the fin 32, which is the second fin. This wiring 35 is an example of a first wiring. Furthermore, another wiring 35 connects the vicinity of the upper end of the SWCNT layer 34 of the fin 32, which is the first fin, to the vicinity of the lower end of the SWCNT layer 34 of the fin 32, which is the third fin. This other wiring 35 is an example of a second wiring.

[0062] [Modification of SWCNT layer] The above-described thermoelectric modules 10, 20, and 30 include a plurality of fins 12 and 32 that function as heat sink fins, and each fin 12 and 32 includes an SWCNT layer 14, 24, or 34. This configuration allows the thermoelectric modules 10, 20, and 30 to not only improve heat dissipation but also generate electricity in response to a temperature difference ΔT between the base and tip of each fin 12 and 32 due to contact of a heat source with the main surfaces 112, 212, and 312 of the substrates 11, 21, and 31. This power generation utilizes the Seebeck effect in the SWCNT layers 14, 24, and 34, and therefore the power generation efficiency depends on the configuration of the SWCNT layers 14, 24, and 34. To improve this power generation efficiency, the SWCNT layers 14, 24, and 34 may be modified as follows:

[0063] Thermoelectric module 10 uses p-SWCNTs to form SWCNT layer 14, thermoelectric module 20 uses n-SWCNTs to form SWCNT layer 24, and thermoelectric module 30 uses p-SWCNTs and n-SWCNTs to form SWCNT layer 34. In our experience, n-nanoink tends to have lower dispersibility than p-nanoink. Therefore, the SWCNT layer of n-SWCNTs tends to be thicker than the SWCNT layer of p-SWCNTs, resulting in a smaller temperature difference ΔT. To improve the dispersibility of n-nanoink, the water in the n-nanoink (n-SWCNTs, water, and cationic surfactant) may be replaced with an organic solvent. By replacing water with an organic solvent, the diameter of the carbon nanotube bundles formed by aggregation of multiple n-SWCNTs tends to decrease, resulting in improved dispersibility.

[0064] In addition, in order to improve power generation efficiency, the length of each fin 12, 32, the length of the section in each fin 12, 32 where the SWCNT layers 14, 24, 34 are formed, and the position of the section in each fin 12, 32 where the SWCNT layers 14, 24, 34 are formed (for example, including the tip and away from the base) can also be adjusted.

[0065] Furthermore, the SWCNT layers 14, 24, and 34 may contain an organic semiconductor that functions as an organic thermoelectric material in addition to SWCNTs. That is, the SWCNT layers 14, 24, and 34 may be a nanocomposite of SWCNTs and an organic semiconductor. An example of a p-type organic semiconductor to be mixed with p-SWCNTs is poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS). Note that the p-type organic semiconductor and n-type organic semiconductor are not limited to these and can be selected appropriately. By appropriately mixing an organic semiconductor that functions as an organic thermoelectric material into the SWCNT layers 14, 24, and 34, the thermoelectric efficiency can be improved. This is because the appropriate mixing of the organic semiconductor reduces the thermal conductivity of the SWCNT layers 14, 24, and 34, thereby increasing the temperature difference ΔT.

[0066] [Embodiment 4] A manufacturing method M10 according to embodiment 4 of the present invention will be described. The manufacturing method M10 is an example of a method for manufacturing the thermoelectric module 10 according to embodiment 1. For ease of explanation, members having the same functions as those described in embodiments 1 and 2 will be denoted by the same reference numerals, and their explanations will not be repeated.

[0067] The manufacturing method M10 includes an insulating layer forming step S11, an SWCNT layer forming step S12, a fin fixing step S13, and a wiring step S14.

[0068] (Insulating layer formation process) The insulating layer forming step S11 is a step of forming an insulating layer on the surfaces of at least some sections (all sections in this embodiment) of the multiple fins 12. Note that if each fin 12 is made of a metal that oxidizes easily, such as aluminum or copper, and if a natural oxide film of sufficient thickness is formed on the surface of each fin 12, the insulating layer forming step S11 may be omitted. Note that the method for forming the insulating layer 13 on the surface of each fin 12 in the insulating layer forming step S11 is not limited. In addition to the natural oxidation described above, existing oxidation techniques such as plasma oxidation and anodic oxidation can also be used. Alternatively, the insulating layer 13 may be formed by depositing an oxide film on the surface of each fin 12.

[0069] (SWCNT layer formation process) The SWCNT layer forming step S12 is a step of forming an SWCNT layer 14 on the insulating layer 13 in the section of each fin 12 where the insulating layer 13 is formed. The SWCNT layer forming step S12 includes a dispersion solution preparing step S121, a dipping step S122, and a drying step S123.

[0070] The dispersion solution preparation step S121 is a step of preparing a dispersion solution containing p-SWCNTs. In this embodiment, ion-exchanged water, p-SWCNTs, and a surfactant are placed in a container (here, a beaker), mixed, and then ultrasonic waves are applied to the mixture using an ultrasonic homogenizer to obtain a dispersion solution containing p-SWCNTs. An example of p-SWCNTs is SG101 ZEONANO (manufactured by Zeon Corporation), an example of a surfactant is sodium dodecyl sulfate (SDS), and an example of an ultrasonic homogenizer is BRANSON SFX 250 (manufactured by EMERSON). However, the p-SWCNTs, surfactant, and ultrasonic homogenizer are not limited to these and can be selected appropriately. Furthermore, the mixing ratio of p-SWCNTs, surfactant, and ion-exchanged water is not limited. Hereinafter, the dispersion solution obtained in the dispersion solution preparation step S121 is referred to as nanoink.

[0071] The dipping step S122 is a step of forming a layer of nanoink on at least a partial section of each fin 12. In this embodiment, the dipping step S122 is performed by impregnating at least a partial section of the multiple fins 12 in the nanoink obtained in the dispersion solution preparation step S121, and then lifting up the multiple fins 12.

[0072] The method for immersing the fins 12 in the nanoink is not limited, but an example is to clamp both ends of the cylindrical fin 12 with a holder and immerse the holder in the nanoink. In the dipping step S122, multiple fins 12 may be immersed in the nanoink together, or the fins 12 may be immersed one by one in order.

[0073] The drying step S123 is a step of drying each fin 12 on which a nanoink layer has been formed in the dipping step S122. By carrying out the drying step S123, the moisture contained in the nanoink is removed, and an SWCNT layer 14 is obtained that is laminated on the surface of the insulating layer 13.

[0074] As described above, by carrying out the SWCNT layer forming step S12, a plurality of fins 12 are obtained in which the insulating layer 13 and the SWCNT layer 14 are stacked within the section in which the insulating layer 13 is formed.

[0075] (Fin fixing process) The fin fixing step S13 is a step of fixing the fin 12 obtained in the SWCNT layer forming step S12 to the main surface 111 of the substrate 11. In this embodiment, one end of the fin 12 is fixed to the main surface 111 using an adhesive 16.

[0076] (Wiring process) As described in the first embodiment, the wiring step S14 is a step of connecting the SWCNT layers 14 of the first fin and the second fin with wiring 15, and also connecting the SWCNT layers 14 of the first fin and the third fin with another wiring 15 (see FIG. 1).

[0077] [Embodiment 5] A manufacturing method M20 according to embodiment 5 of the present invention will be described. The manufacturing method M20 is an example of a method for manufacturing the thermoelectric module 20 according to embodiment 2. The manufacturing method M20 can also be considered a modified example of the manufacturing method M10 according to embodiment 1. Therefore, for the sake of convenience, the same reference numerals will be used to designate components and steps having the same functions as those described in embodiments 2 and 4, and their description will not be repeated.

[0078] The manufacturing method M20 includes an insulating layer forming step S11, an SWCNT layer forming step S22, a fin fixing step S23, and a wiring step S14.

[0079] The insulating layer forming step S11 has already been described in the fourth embodiment, and therefore will not be described here.

[0080] The SWCNT layer forming step S22 corresponds to the SWCNT layer forming step S12 of the manufacturing method M10, and includes a dispersion solution preparing step S221, a dipping step S222, and a drying step S123.

[0081] The dispersion solution preparation step S221 is a step of preparing a dispersion solution containing p-SWCNTs and a dispersion solution containing n-SWCNTs. The step of preparing the dispersion solution containing p-SWCNTs is the same as the dispersion solution preparation step S121. Hereinafter, the dispersion solution containing p-SWCNTs obtained here will be referred to as p-nanoink.

[0082] The process for preparing a dispersion solution containing n-SWCNTs involves placing ion-exchanged water, n-SWCNTs, and a surfactant in a container (here, a beaker), mixing them, and then applying ultrasonic waves to the mixture using an ultrasonic homogenizer. An example of n-SWCNTs is SG-CNT ZEONANO (manufactured by Zeon Corporation), and an example of a surfactant is 1-Octadecaneammonium, N,N-dimethyl-N-octadecylchloride (DODMAC). However, the n-SWCNTs, surfactant, and ultrasonic homogenizer are not limited to these and can be selected appropriately. Furthermore, the mixing ratio of n-SWCNTs, surfactant, and ion-exchanged water is not limited. Hereinafter, the dispersion solution containing n-SWCNTs obtained here is referred to as n-nanoink.

[0083] The dipping process S222 is a process of forming a layer of p-nanoink on at least a partial section of the fin 12, and forming a layer of n-nanoink on at least a partial section of another fin 12. Note that the formation of a layer of p-nanoink on at least a partial section of the fin 12 is the same process as the dipping process S122.

[0084] The step of forming a layer of n-nanoink on at least a portion of another fin 12 is a step of impregnating at least a portion of the fin 12 in n-nanoink and then lifting up the multiple fins 12. In other words, the step of forming a layer of n-nanoink on at least a portion of another fin 12 is a step based on the dipping step S122, but using n-nanoink instead of p-nanoink.

[0085] The drying step S123 has already been described in the fourth embodiment, so a description thereof will be omitted here.

[0086] By carrying out the SWCNT layer formation step S22, (1) a plurality of fins 12 are obtained in which an insulating layer 13 and an SWCNT layer 24 made of p-SWCNT are stacked within the section in which the insulating layer 13 is formed, and (2) a plurality of fins 12 are obtained in which an insulating layer 13 and an SWCNT layer 24 made of n-SWCNT are stacked within the section in which the insulating layer 13 is formed.

[0087] The fin fixing step S23 corresponds to the fin fixing step S13 in the manufacturing method M10. That is, the fin fixing step S23 is a step of fixing the fins 12 obtained in the SWCNT layer forming step S22 to the main surface 211 of the substrate 21. The fins 12 obtained in the SWCNT layer forming step S22 include fins 12 on which the SWCNT layer 24 made of p-SWCNTs is formed and fins 12 on which the SWCNT layer 24 made of n-SWCNTs is formed.

[0088] In the fin fixing step S23, as shown in FIG. 2, fins 12 having SWCNT layers 24 made of p-SWCNTs and fins 12 having SWCNT layers 24 made of n-SWCNTs are arranged alternately so that the SWCNT layers 24 of two adjacent fins 12 among the plurality of fins 12 are composed of different types of S-SWCNTs.

[0089] As described in the second embodiment, a plurality of holes are formed in a matrix (or lattice) of n rows and m columns on the main surface 212 of the base material 21. In the fin fixing step S23, the base of each fin 12 is inserted into each hole formed on the main surface 211, thereby fixing each fin 12 to the main surface 211.

[0090] The wiring step S14 has already been described in the fourth embodiment, so a description thereof will be omitted here.

[0091] [Embodiment 6] A manufacturing method M30 according to a sixth embodiment of the present invention will be described. The manufacturing method M30 is an example of a method for manufacturing the thermoelectric module 30 according to the third embodiment. The manufacturing method M30 can be considered a modified version of the manufacturing method M10 according to the fourth embodiment, or a modified version of the manufacturing method M20 according to the fifth embodiment. Therefore, for the sake of convenience, the same reference numerals will be used to designate components and steps having the same functions as those described in the first, second, fourth, and fifth embodiments, and the description thereof will not be repeated.

[0092] The manufacturing method M30 includes an insulating layer forming step S31, an SWCNT layer forming step S32, and a wiring step S14.

[0093] The insulating layer forming step S31 is a step of forming an insulating layer 33 on the surfaces of at least some sections (all sections in this embodiment) of the multiple fins 32 and on the main surfaces 311 by oxidizing the surfaces of aluminum constituting the integrally molded base material 31 and multiple fins 32. In this embodiment, the insulating layer 33 made of an aluminum oxide film is formed by subjecting the main surfaces 311 and the surfaces of the fins 32 to plasma oxidation. However, the method of forming the insulating layer 33 is not limited to plasma oxidation. The method of oxidizing the surfaces of the main surfaces 311 and the fins 32 may be natural oxidation or anodic oxidation. Alternatively, the insulating layer 33 may be formed by depositing an oxide film on the surfaces of the main surfaces 311 and the fins 32.

[0094] The SWCNT layer formation process S32 is a process in which, in the section S of each fin 32, (1) in the first section S1, a first SWCNT layer 341 is formed consisting of one of p-type and n-type S-SWCNTs (p-SWCNT and n-SWCNT) that exhibit semiconducting conductive properties (p-SWCNT in this embodiment), and (2) in the second section S2, a second SWCNT layer 342 is formed consisting of the other of the p-type and n-type S-SWCNTs (n-SWCNT in this embodiment).

[0095] The SWCNT layer forming step S32 corresponds to the SWCNT layer forming step S12 of manufacturing method M10 and the SWCNT layer forming step S22 of manufacturing method M20. That is, the SWCNT layer forming step S32 includes a dispersion solution preparing step S321, a dipping step S322, and a drying step S123.

[0096] The dispersion solution preparation step S321 is a step of preparing a dispersion solution containing p-SWCNTs (i.e., p-nanoink) and a dispersion solution containing n-SWCNTs (i.e., n-nanoink), and is the same step as the dispersion solution preparation step S221 in manufacturing method M20, so its description will be omitted here.

[0097] The dipping step S322 is a step of (1) forming a layer of p-nanoink in the first section S1 of the section S of each fin 32, and (2) forming a layer of n-nanoink in the second section S2.

[0098] In this embodiment, first, the sections S of all the fins 32 are impregnated with p-nanoink, and then all the fins 32 are pulled up, thereby forming a layer of p-nanoink over the entire sections S of all the fins 32 .

[0099] Next, the second section S2 of the section S is inserted into ion-exchanged water, and the p-nanoink formed in the second section S2 is washed away.

[0100] Next, the second section S2 of the section S is impregnated with the n-nanoink, and then the second section S2 is pulled up, thereby forming a layer of the n-nanoink in the second section S2.

[0101] The drying step S123 has already been described in the fourth embodiment, so a description thereof will be omitted here.

[0102] By carrying out the SWCNT layer formation process S32, an insulating layer 13 and a first SWCNT layer 341 are stacked in the first section S1, and multiple fins 32 are obtained in the second section S2, each having an insulating layer 13 and a second SWCNT layer 342 stacked thereon.

[0103] The wiring step S14 has already been described in the fourth embodiment, so a description thereof will be omitted here.

[0104] [Additional Notes] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention. [Example]

[0105] Examples 1 to 3 of the present invention and a comparative example of the present invention will be described with reference to FIGS. 4 to 10. FIG. 4 is a graph showing the time dependence of the temperature obtained when a thermoelectric module according to the comparative example is heated. In FIG. 4, the temperatures at the base and tip of the fins are shown by thick and thin lines, respectively. FIG. 5 is a graph showing the time dependence of the temperature obtained when a thermoelectric module according to Example 1 is heated. In FIG. 5, the temperatures at the base and tip of the fins are shown by thick and thin lines, respectively. FIG. 6 is a graph showing the time dependence of the temperature difference between the base and tip of the fin obtained in each of the thermoelectric modules according to Example 1 and the comparative example. In FIG. 6, Example 1 and the comparative example are shown by thick and thin lines, respectively. FIG. 7 is a graph showing the time dependence of the output voltage obtained in the thermoelectric module according to Example 1. FIGS. 8 to 10 are graphs showing the temperature difference dependence of the output voltage obtained in the thermoelectric modules according to Examples 1 to 3, respectively. In each of FIGS. 8 to 10, a straight line obtained by the least squares method using a linear function passing through the origin is shown by a broken line.

[0106] Example 1 is an example of the thermoelectric module 10 according to embodiment 1 and the manufacturing method M10 according to embodiment 4. In Example 1, the SWCNT layer 14 made of p-SWCNTs was used.

[0107] Specifically, in the dispersion solution preparation step S121 of the SWCNT layer formation step S12 included in production method M10, SG101 ZEONANO (manufactured by Zeon Corporation) was used as the p-SWCNT, SDS (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was used as the surfactant, and a BRANSON SFX 250 (manufactured by EMERSON) was used as the ultrasonic homogenizer. Here, 0.08 g of SG101 and 0.2 g of SDS were added to 40 ml of ion-exchanged water, and the ultrasonic output of the BRANSON SFX 250 was set to 70%. Ultrasonic waves were applied for 1 hour to obtain p-nanoink.

[0108] Note that explanations of steps other than the dispersion solution preparation step S121 included in the manufacturing method M10 will be omitted here.

[0109] Example 2 is an example of the thermoelectric module 10 according to embodiment 1 and the manufacturing method M10 according to embodiment 4. In Example 2, the SWCNT layer 14 made of n-SWCNTs was used.

[0110] Specifically, in the dispersion solution preparation step S121 of the SWCNT layer formation step S12 included in the manufacturing method M10, n-nanoink was prepared instead of p-nanoink.

[0111] Specifically, in the step of preparing the n-nanoink in the dispersion solution preparation step S221 of the SWCNT layer formation step S22 included in the manufacturing method M20 according to embodiment 5, SG-CNT ZEONANO (manufactured by Zeon Corporation) was used as an example of n-SWCNT, DODMAC was used as the surfactant, and a BRANSON SFX 250 was used as the ultrasonic homogenizer. Here, 0.08 g of SG-CNT and 0.4 g of DODMAC were added to 40 ml of ion-exchanged water, and the ultrasonic output of the BRANSON SFX 250 was set to 70%. Ultrasonic waves were applied for 1 hour to obtain the n-nanoink.

[0112] Example 3 is an example of the thermoelectric module 20 according to embodiment 2 and the manufacturing method M20 according to embodiment 5. That is, in Example 3, as shown in Fig. 2, a SWCNT layer 24 made of p-SWCNTs was used in each of the fins 12 where n = i-2, i, i+2, and a SWCNT layer 24 made of n-SWCNTs was used in each of the fins 12 where n = i-1, i+1, i+3. Note that a description of the processes for producing p-nanoink and n-nanoink will be omitted here.

[0113] The comparative example was obtained by omitting the SWCNT layer 14 formed on each fin 12 from the thermoelectric module 10 of Example 1. In other words, the comparative example does not function as a thermoelectric module, but is simply a heat sink.

[0114] Using Example 1, the main surface 112 of the substrate 11 was placed on the heat generating surface of a hot plate type heater, the temperature of the heater was set to 180°C, and the elapsed time and the temperature of the thermoelectric module 10 were measured. The temperature of the thermoelectric module 10 was measured at each of the base and tip of the fins 12.

[0115] In Examples 2 and 3, the heater temperature was set to 180° C., and the elapsed time and the temperatures at the base and tip of the fin 12 were measured, as in Example 1. The same was true for the comparative example.

[0116] In addition, in Examples 1 to 3, the output voltages of the thermoelectric modules 10 and 20 were measured along with the elapsed time and the temperature of the fins 12.

[0117] 4 and 5, it was found that in both the comparative example and example 1, the temperature of the fins increased with heating and eventually saturated. It was also found that in both the comparative example and example 1, the temperature of the base of the fins increased to approximately 170°C. On the other hand, it was found that the temperature of the tip of the fins in the comparative example only increased to approximately 100°C, whereas the temperature of the tip of the fins in example 1 increased to approximately 150°C.

[0118] Furthermore, referring to FIG. 6, it was found that the temperature difference between the base and tip of the fin was approximately 75° C. and approximately 20° C. in the comparative example and Example 1, respectively.

[0119] From the above results, it was found that in the thermoelectric module 10, the surface of each fin 12 is covered not only with the insulating layer 13 made of a natural oxide film but also with the SWCNT layer 14, which increases the thermal conduction from the base to the tip of the fin 12, thereby improving the heat dissipation performance as a heat sink.

[0120] 7, it was found that the output voltage of Example 1 increases with heating and eventually saturates. Also, it was found that the temperature difference between the base and tip of the fin 12 is proportional to the output voltage.

[0121] Furthermore, referring to FIGS. 9 and 10, it was found that in each of Examples 2 and 3, the temperature difference occurring between the base and tip of the fin 12 and the output voltage were proportional to each other.

[0122] 8 to 10, the slopes of the lines obtained by the least squares method for Examples 1 to 3 were 38 μV / K, 10 μV / K, and 10 μV / K, respectively. The greater the slope, the higher the power generation efficiency. Therefore, it was found that, among Examples 1 to 3, Example 1 had the highest power generation efficiency, and Examples 2 and 3 had similar power generation efficiencies.

[0123] 〔summary〕 In order to improve heat dissipation performance compared to conventional thermoelectric modules (described in Patent Document 1), a thermoelectric module according to a first aspect of the present invention includes a base material, a plurality of fins protruding from a first region of the base material, the fins being made of metal or semiconductor and having at least a portion of their base-to-tip sections covered with an insulating layer, a single-walled carbon nanotube (SWCNT) layer provided on top of the insulating layer within the portion of the fins, and a first wiring connecting the SWCNT layers of the first fin and the second fin, when one of the fins is defined as a first fin and two fins adjacent to the first fin are defined as a second fin and a third fin, respectively, and a second wiring connecting the SWCNT layers of the first fin and the third fin.

[0124] In order to improve heat dissipation performance compared to conventional thermoelectric modules (described in Patent Document 1), a thermoelectric module according to a second aspect of the present invention includes a substrate, a plurality of fins protruding from a first region of the substrate, the fins being made of fine ceramics, a single-walled carbon nanotube (SWCNT) layer covering each fin in at least a portion of the section from the base to the tip of each fin, and, when one of the plurality of fins is defined as a first fin and two fins adjacent to the first fin are defined as second fin and third fin, a first wiring connecting the SWCNT layers of the first fin and the second fin, and a second wiring connecting the SWCNT layers of the first fin and the third fin.

[0125] According to the above configuration, at least a portion of the fin is covered with an insulating layer and an SWCNT layer, and the SWCNT layers of adjacent fins are connected by first and second wirings, allowing the multiple SWCNT layers to function as a thermoelectric device. Furthermore, the SWCNTs constituting the SWCNT layer have a higher thermal conductivity than metals or fine ceramics (e.g., aluminum, alumina, etc.) that are widely used as heat sink materials. Therefore, the thermal resistance between the substrate and the tip of each fin can be reduced, and the thermoelectric module according to the first or second aspect can improve heat dissipation performance compared to conventional thermoelectric modules.

[0126] Furthermore, in a thermoelectric module according to a third aspect of the present invention, in addition to the configuration of the thermoelectric module according to the first or second aspect described above, a configuration is adopted in which the partial section includes the tip, and the tip is covered with the SWCNT layer.

[0127] According to the above configuration, the surface area of ​​each fin can be effectively utilized to dissipate heat, thereby further improving heat dissipation.

[0128] Furthermore, in a thermoelectric module according to a fourth aspect of the present invention, in addition to the configuration of the thermoelectric module according to the first or second aspect described above, a configuration is adopted in which all SWCNT layers are composed of one type of S-SWCNT that exhibits semiconducting conductive properties.

[0129] According to the above configuration, the thermoelectric module according to one aspect of the present invention can be easily manufactured.

[0130] Furthermore, in a thermoelectric module according to a fifth aspect of the present invention, in addition to the configuration of the thermoelectric module according to the first or second aspect described above, a configuration is adopted in which each SWCNT layer is composed of p-type or n-type S-SWCNTs that exhibit semiconducting conductive properties, and the SWCNT layers of two adjacent fins among the plurality of fins are composed of different types of S-SWCNTs.

[0131] According to the above configuration, it is possible to improve the heat dissipation performance in a thermoelectric module that utilizes a pn junction.

[0132] Furthermore, in a thermoelectric module according to a sixth aspect of the present invention, in addition to the configuration of the thermoelectric module according to the first or second aspect described above, the following configuration is adopted: of the partial sections of each fin, a section close to the base is defined as a first section, and a section close to the tip is defined as a second section, the first section and the second section are in contact with each other, the SWCNT layer provided in the first section is composed of one of p-type and n-type S-SWCNTs that exhibit semiconducting conductive properties, and the SWCNT layer provided in the second section is composed of the other of the p-type and n-type S-SWCNTs.

[0133] According to the above configuration, a pn junction can be provided in a partial section of each fin, which makes it easier to improve power generation efficiency compared to when all SWCNT layers are composed of a single type of S-SWCNT, or when the SWCNT layers of two adjacent fins are composed of S-SWCNT layers of different types (p-type and n-type).

[0134] Furthermore, in a thermoelectric module according to a seventh aspect of the present invention, in addition to the configuration of the thermoelectric module according to the first or second aspect described above, a configuration is adopted in which the plurality of fins are pin fins each made of a columnar member.

[0135] According to the above configuration, the sum of the surface areas of the fins can be increased compared to when fins made of plate-like members are used, thereby further improving heat dissipation.

[0136] Furthermore, in a thermoelectric module according to an eighth aspect of the present invention, in addition to the configuration of the thermoelectric module according to the first or second aspect described above, a configuration is adopted in which the SWCNT layers provided on each of the plurality of fins are connected in series using the first wiring and the second wiring, and output terminals are provided on both ends of the plurality of SWCNT layers connected in series.

[0137] According to the above configuration, the electric power generated in each SWCNT layer can be output to the outside of the thermoelectric module via the output terminal.

[0138] A thermoelectric system according to a ninth aspect of the present invention includes the thermoelectric module according to the first or second aspect described above, and a heat source. The thermoelectric system employs a configuration in which the heat source is disposed in a second region of the base material that is different from the first region and in which the fins are not formed. As described above, the thermoelectric module according to the first or second aspect can improve heat dissipation compared to conventional thermoelectric modules. Therefore, according to the above configuration, the heat dissipation in the thermoelectric system can be improved compared to conventional thermoelectric modules. [Explanation of symbols]

[0139] 10, 20, 30 Thermoelectric Module 11,21,31 Base material 111,112,211,212,311,312 Main surfaces 12,32 Multiple fins 13,33 Insulating layer 14,24,34 SWCNT layers S section S1 First Section S2 2nd Section 341 1st SWCNT layer 342 2nd SWCNT layer 15 Wiring 16 Adhesive

Claims

1. A substrate; a plurality of fins protruding from a first region of the substrate, the fins being made of metal or semiconductor, and at least a portion of a section from a base to a tip being covered with an insulating layer; a single-walled carbon nanotube (SWCNT) layer provided on the insulating layer in the partial section; When any one of the plurality of fins is designated as a first fin and two fins adjacent to the first fin are designated as a second fin and a third fin, the fin is provided with a first wiring that connects SWCNT layers of the first fin and the second fin, and a second wiring that connects SWCNT layers of the first fin and the third fin, Thermoelectric module.

2. A substrate; a plurality of fins protruding from a first region of the base material, the fins being made of fine ceramics; a single-walled carbon nanotube (SWCNT) layer covering each fin in at least a portion of the section from the base to the tip of each fin; When any one of the plurality of fins is designated as a first fin and two fins adjacent to the first fin are designated as a second fin and a third fin, the fin is provided with a first wiring that connects SWCNT layers of the first fin and the second fin, and a second wiring that connects SWCNT layers of the first fin and the third fin, Thermoelectric module.

3. the partial section includes the tip, The tip is covered with the SWCNT layer. The thermoelectric module according to claim 1 or 2.

4. The entire SWCNT layer is composed of one type of S-SWCNT, which exhibits semiconducting conductive properties. The thermoelectric module according to claim 1 or 2.

5. Each SWCNT layer is composed of p-type or n-type S-SWCNTs that exhibit semiconducting conductive properties, the SWCNT layers of two adjacent fins among the plurality of fins are composed of different types of S-SWCNTs; The thermoelectric module according to claim 1 or 2.

6. Of the partial sections of each fin, a section close to the base is defined as a first section, and a section close to the tip is defined as a second section, The first section and the second section are in contact with each other, The SWCNT layer provided in the first section is composed of either p-type or n-type S-SWCNTs exhibiting semiconducting conductive properties, the SWCNT layer provided in the second section is composed of the other of the p-type and n-type S-SWCNTs; The thermoelectric module according to claim 1 or 2.

7. The plurality of fins are pin fins, each of which is made of a columnar member. The thermoelectric module according to claim 1 or 2.

8. the SWCNT layers provided on each of the plurality of fins are connected in series using the first wiring and the second wiring; The SWCNT layer may further include output terminals provided at both ends of the plurality of SWCNT layers connected in series. The thermoelectric module according to claim 1 or 2.

9. The thermoelectric module according to claim 1 or 2; a heat source; the heat source is disposed in a second region of the base material that is different from the first region and in which the fins are not formed. Thermoelectric systems.

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