Thermoelectric conversion module

Abstract

To provide a thermoelectric conversion module that can more efficiently suppress heat (more precisely, radiation heat) conducting from a high temperature side to a low temperature side in a space existing between a plurality of thermoelectric conversion elements.SOLUTION: A thermoelectric conversion module 1 of the present invention includes a first electrically insulating substrate 2, a second electrically insulating substrate 3, a plurality of thermoelectric conversion elements 4a and 4b, connection wires 5 and 6, and a radiation heat reflection member including at least one first radiation heat reflection plate 7. The first radiation heat reflection plate 7 includes a first electrically insulating plate 11, a first reflection layer 12 formed on at least one surface of the first electrically insulating plate 11 and disposed in contact with the thermoelectric conversion elements 4a and 4b, and a plurality of independent holes 10 with the size that enables the thermoelectric conversion elements 4a and 4b to pass therethrough. The first reflection layer 12 includes an electrically insulating part 13 that electrically insulates between the thermoelectric conversion elements 4a and 4b.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a thermoelectric conversion module having a structure in which a plurality of thermoelectric conversion elements are alternately and electrically connected in series. [Background technology]

[0002] Thermoelectric conversion modules that utilize the Seebeck effect can convert thermal energy into electrical energy. When actually performing thermoelectric conversion, it is common to use p-type and n-type thermoelectric conversion elements, which are electrically connected in series in an alternating fashion. Such thermoelectric conversion modules can effectively utilize the heat emitted from industrial and consumer processes and moving objects and convert it into electricity, so thermoelectric conversion has attracted attention as an environmentally friendly energy-saving technology.

[0003] As an example of a conventional thermoelectric conversion module, Patent Document 1 describes a heat loss prevention structure that prevents heat loss caused by heat being transferred by thermal radiation or convection in the gaps between thermoelectric conversion elements or thermoelectric conversion modules and reaching the low-temperature side system through the gaps without passing through the thermoelectric conversion elements. Patent Document 1 also describes that the heat loss prevention structure is configured by arranging multiple radiation prevention plates in multiple stages so as to divide the internal space formed by the high-temperature side insulating substrate and the low-temperature side insulating substrate into multiple flat small spaces. It also describes that the radiation prevention plates are made of a material with high heat reflectivity, such as stainless steel, Ni-plated iron, aluminum (alumite), zinc, etc.

[0004] In the thermoelectric conversion module described in Patent Document 1, by providing a radiation prevention plate, heat absorption from the high-temperature side system can be efficiently guided to each thermoelectric conversion element of the thermoelectric conversion module, thereby improving thermoelectric conversion performance.

[0005] However, the thermoelectric conversion module described in Patent Document 1 does not take into consideration insulating the thermoelectric conversion elements from each other at the radiation prevention plate, and there is a risk of short-circuiting between the thermoelectric conversion elements.

[0006] Patent Document 2 also discloses a configuration in which a plurality of thermoelectric conversion elements are sandwiched between a pair of electrically insulating substrates, a porous insulating layer is filled in the region between the plurality of thermoelectric conversion elements, and a reflective metal layer is disposed in the middle of the porous insulating layer in the height direction in order to suppress heat transfer from the high temperature side to the low temperature side in the region (space) between the thermoelectric conversion elements. It further discloses that the reflective metal layer is disposed 20 μm to 200 μm away from the thermoelectric conversion elements, and a porous insulating layer is inserted between them to form an electrically insulating state.

[0007] In the thermoelectric conversion module described in Patent Document 2, the spaces between the thermoelectric conversion elements are filled with a porous insulating layer, thereby preventing heat transfer due to gas convection, and the reflective metal layer reflects thermal radiation, thereby restricting the transfer of heat due to radiation between high-temperature and low-temperature areas. Furthermore, the reflective metal layer is electrically insulated from the thermoelectric conversion elements, and does not adversely affect the thermoelectromotive force.

[0008] However, the thermoelectric conversion module described in Patent Document 2 has a porous resin layer such as an epoxy resin, which transmits radiant heat, and therefore it is not possible to obtain an excellent radiation suppression effect. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Patent No. 4481606 [Patent Document 2] Patent No. 5598152 Summary of the Invention [Problem to be solved by the invention]

[0010] An object of the present invention is to provide a thermoelectric conversion module that can more efficiently suppress heat (more precisely, radiant heat) transferred from the high-temperature side to the low-temperature side in the space between multiple thermoelectric conversion elements. [Means for solving the problem]

[0011] In order to achieve the above object, the gist of the present invention is as follows. (1) In a usage environment with a temperature difference, a thermoelectric conversion module having a first electrically insulating substrate disposed on a high temperature side, a second electrically insulating substrate disposed on a low temperature side and generally parallel to the first electrically insulating substrate at a distance therefrom, a plurality of thermoelectric conversion elements sandwiched between the first and second electrically insulating substrates, and connection wiring disposed between the first electrically insulating substrate and the plurality of thermoelectric conversion elements and between the second electrically insulating substrate and the plurality of thermoelectric conversion elements, the thermoelectric conversion module having a temperature difference between the first and second electrically insulating substrates, a radiant heat reflecting member constituted by at least one first radiant heat reflecting plate arranged substantially parallel to the first and second electrically insulating substrates, the first radiant heat reflecting plate having a first electrically insulating plate, a first reflective layer that reflects radiant heat and is formed on at least one side of the first electrically insulating plate and arranged so as to be in contact with the thermoelectric conversion elements, and a plurality of independent holes of a size that allows the plurality of thermoelectric conversion elements to pass through, the first reflective layer having an electrical insulating portion that electrically insulates the plurality of thermoelectric conversion elements from each other. (2) The thermoelectric conversion module described in (1) above, wherein the first radiant heat reflecting plate has the first reflecting layer and a second reflecting layer that reflects radiant heat and is arranged on both sides of the first electrically insulating plate so as not to contact the thermoelectric conversion element. (3) The thermoelectric conversion module described in (1) or (2) above, wherein the radiant heat reflecting member further includes at least one second radiant heat reflecting plate having a second electrically insulating plate and a second reflecting layer that reflects radiant heat and is formed on only one side or both sides of the second electrically insulating plate and arranged so as not to contact the thermoelectric conversion element. (4) A thermoelectric conversion module described in (3) above, wherein the outer area of ​​the first electrically insulating plate and the outer area of ​​the second electrically insulating plate are both the same as or larger than the outer area of ​​either the first electrically insulating substrate or the second electrically insulating substrate. (5) The thermoelectric conversion module according to (3) or (4) above, wherein the thermal conductivity of the first electrical insulating plate and the second electrical insulating plate is both lower than the thermal conductivity of the thermoelectric conversion element. (6) The thermoelectric conversion module according to any one of (2) to (5) above, wherein the first reflective layer and the second reflective layer are both formed by dry plating or wet plating. (7) A thermoelectric conversion module described in any one of (1) to (6) above, further comprising a side radiant heat reflector arranged so as to substantially surround the radiant heat reflecting member and the second electrically insulating substrate. (8) The thermoelectric conversion module described in (7) above, wherein the side radiant heat reflecting plate has a third electrically insulating plate and a third reflecting layer formed on one surface of the third electrically insulating plate and reflecting radiant heat, and the other surface of the third electrically insulating plate is arranged to face a side of the radiant heat reflecting member and a side of the second electrically insulating substrate. (9) The thermoelectric conversion module according to (8) above, wherein the thermal conductivity of the third electrically insulating plate is lower than the thermal conductivity of the thermoelectric conversion element. Effect of the Invention

[0012] An object of the present invention is to provide a thermoelectric conversion module that can more efficiently suppress heat (more precisely, radiant heat) transferred from the high-temperature side to the low-temperature side in the space between multiple thermoelectric conversion elements. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a perspective view of a thermoelectric conversion module according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II of the thermoelectric conversion module shown in FIG. [Diagram 3]FIG. 3 is a perspective view showing the thermoelectric conversion module shown in FIG. 1 with a first electrically insulating substrate and a first radiant heat reflecting plate removed. [Figure 4] FIG. 4 is a plan view showing an example of the first reflective layer. [Diagram 5] FIG. 5 is a plan view showing another example of the first reflective layer. [Figure 6] Fig. 6(a) is a diagram for explaining how radiant heat is transmitted when a first light-transmitting electrically insulating plate has a first reflective layer on both sides of which the electrical insulating parts are formed in different configurations. Fig. 6(b) is a diagram for explaining how radiant heat is transmitted when a radiant heat reflecting member is composed of two light-transmitting first electrically insulating plates, and these two first electrically insulating plates each have a first reflective layer on which the electrical insulating parts are formed in different configurations. Fig. 6(c) is a diagram for explaining how radiant heat is transmitted when a first non-light-transmitting electrically insulating plate has a first reflective layer on both sides of which the electrical insulating parts are formed in different configurations. Figure 6(d) is a diagram illustrating how radiant heat is transmitted when the radiant heat reflecting member is composed of two non-translucent first electrically insulating plates, and these two first electrically insulating plates each have a first reflective layer in which the electrical insulating portion is formed in a different arrangement shape. [Figure 7] FIG. 7 is a cross-sectional view of a thermoelectric conversion module according to the second embodiment. [Figure 8] FIG. 8 is a cross-sectional view of a thermoelectric conversion module according to the third embodiment. [Figure 9] FIG. 9 is a cross-sectional view of a thermoelectric conversion module according to the fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Next, various embodiments of thermoelectric conversion modules according to the present invention will be described below.

[0015] <First embodiment> FIG. 1 is a perspective view showing a thermoelectric conversion module of a first embodiment according to the present invention, FIG. 2 is a cross-sectional view of the thermoelectric conversion module shown in FIG. 1 along line II, and FIG. 3 is a perspective view showing the thermoelectric conversion module shown in FIG. 1 with a first electrically insulating substrate and a first radiant heat reflector removed.

[0016] The thermoelectric conversion module 1 of the first embodiment has a structure capable of converting thermal energy into electrical energy (power) in a usage environment with a temperature difference by utilizing the Seebeck effect.

[0017] The illustrated thermoelectric conversion module 1 is mainly composed of a first electrically insulating substrate 2, a second electrically insulating substrate 3, a plurality of thermoelectric conversion elements 4, first and second connection wirings 5 ​​and 6, and a first radiant heat reflector .

[0018] The first electrically insulating substrate 2 is disposed on the high temperature side, and the second electrically insulating substrate 3 is disposed approximately parallel to and spaced from the first electrically insulating substrate 2 on the low temperature side.

[0019] The first electrically insulating substrate 2 and the second electrically insulating substrate 3 must have electrical insulation, and preferably have excellent thermal conductivity, but there is no particular restriction on the material or structure. For example, the electrically insulating substrates 2 and 3 may have electrical insulation at least on the surface. Suitable examples of the electrically insulating substrates 2 and 3 include materials having electrical insulation and high thermal conductivity, such as ceramic materials such as alumina (Al2O3), aluminum nitride (AlN), and silicon nitride (Si3N4), and glass epoxy substrates and glass substrates can also be used under conditions of use at temperatures of about 200°C or less. Furthermore, the electrically insulating substrates 2 and 3 can be metal substrates such as copper, copper alloys, aluminum, and aluminum alloys, the surfaces of which are covered with an insulating layer, and the electrically insulating substrates 2 and 3 having such a configuration are preferable in that they can increase thermal conductivity.

[0020] In the first embodiment, a plurality of columnar thermoelectric conversion elements 4, such as cylindrical or rectangular thermoelectric conversion elements, are arranged alternately at intervals between a first electrically insulating substrate 2 disposed on the high temperature side and a second electrically insulating substrate 3 disposed on the low temperature side, and are sandwiched between the first electrically insulating substrate 2 and the second electrically insulating substrate 3, so as to be arranged in a lattice, matrix or row shape as a whole.

[0021] Each thermoelectric conversion element 4 has a first electrode 8 formed on the end face facing the first electrically insulating substrate 2, and a second electrode 9 formed on the end face facing the second electrically insulating substrate 3. In addition, a first connection wiring 5 and a second connection wiring 6 are formed on the opposing surfaces of the first electrically insulating substrate 2 and the second electrically insulating substrate 3, respectively.

[0022] The first connection wiring 5 and the second connection wiring 6 are respectively arranged between the first electrically insulating substrate 2 and the multiple thermoelectric conversion elements 4 (one end surface) and between the second electrically insulating substrate 3 and the multiple thermoelectric conversion elements 4 (the other end surfaces) to connect the multiple thermoelectric conversion elements 4, 4.

[0023] The material of the first connection wiring 5 and the second connection wiring 6 is not particularly limited, but examples thereof include copper, copper alloy, etc. The first connection wiring 5 and the second connection wiring 6 are formed in a rectangular planar shape in Fig. 3. The size (planar size) of the first connection wiring 5 and the second connection wiring 6 is set to be the same as or slightly larger than the area of ​​the end face of the thermoelectric conversion element 4 depending on the size of the thermoelectric conversion element 4 connected to the first connection wiring 5 and the second connection wiring 6.

[0024] 1 to 3, a plurality of thermoelectric conversion elements 4, for example a plurality of p-type thermoelectric conversion elements 4a and a plurality of n-type thermoelectric conversion elements 4b, are connected to a first connection wiring 5 via a first electrode 8 and to a second connection wiring 6 via a second electrode 9, so that the p-type thermoelectric conversion elements 4a and the n-type thermoelectric conversion elements 4b are electrically connected in series. The thermoelectric conversion elements 4a, 4b can be connected to the first and second connection wirings 5, 6 by bonding (adhesion) using, for example, silver paste or the like.

[0025] The first electrode 8 and the second electrode 9 are not particularly limited, but can be formed by plating, vapor deposition, or the like using a metal such as Ni or an alloy.

[0026] The thermoelectric conversion material used in the thermoelectric conversion element 4 is not particularly limited, and examples thereof include bismuth-tellurium compounds, silicon-germanium (Si-Ge) compounds, silicide compounds, skutterudite compounds, clathrate compounds, Heusler compounds, and half-Heusler compounds. In this embodiment, it is preferable to use a clathrate compound as the thermoelectric conversion material of the thermoelectric conversion element 4 for at least one of the p-type thermoelectric conversion element 4a and the n-type thermoelectric conversion element 4b. The clathrate compound can reduce thermal conductivity, and by changing the composition of the clathrate compound, optimal performance can be obtained for that temperature range, so that the thermoelectric conversion efficiency of the thermoelectric conversion module 1 can be improved.

[0027] Moreover, the thermoelectric conversion element 4 formed from a clathrate compound is particularly preferable in that it does not contain environmentally hazardous substances such as bismuth (Bi), tellurium (Te), and selenium (Se), and can be manufactured by separately producing p-type thermoelectric conversion material and n-type thermoelectric conversion material.

[0028] The dimensions of each thermoelectric conversion element 4 are not particularly limited. For example, in the case of a prismatic thermoelectric conversion element 4 as shown in FIG. 1, the thermoelectric conversion element 4 has a rectangular shape with a side length of about 0.5 mm to 3 mm when viewed in cross section, and a height dimension of about 2 mm to 20 mm.

[0029] In addition, the thermoelectric conversion module 1 of this embodiment has a radiant heat reflecting member composed of at least one first radiant heat reflecting plate 7 arranged approximately parallel to the first electrically insulating substrate 2 and the second electrically insulating substrate 3 between the first electrically insulating substrate 2 and the second electrically insulating substrate 3.

[0030] Fig. 4 is a plan view showing the first reflective layer 12. As shown in Fig. 4, the first radiant heat reflecting plate 7 has a plurality of independent holes 10, 10 of a size that allows a plurality of thermoelectric conversion elements 4, 4 to pass through. The independent holes 10 are formed in the same number as the number of thermoelectric conversion elements 4 constituting the thermoelectric conversion module 1, and the positions of the independent holes 10 formed in the first radiant heat reflecting plate 7 coincide with the positions of the thermoelectric conversion elements 4.

[0031] Furthermore, when the thermoelectric conversion module 1 is constructed, in order to suppress heat transfer from the high temperature side to the low temperature side in the region (space) between the thermoelectric conversion elements 4, 4, it is preferable to set the shape and dimensions of the independent holes 10 in the first radiant heat reflecting plate 7 in accordance with the contour shape and dimensions of the side surface of the thermoelectric conversion element 4 so that no gaps are generated between the independent holes 10 formed in the first radiant heat reflecting plate 7 and the thermoelectric conversion elements 4 inserted into the independent holes 10. The first radiant heat reflecting plate 7 shown in Fig. 4 shows a case in which 16 rectangular independent holes 10 are arranged in a lattice pattern.

[0032] The first radiant heat reflecting plate 7 preferably has a first electrically insulating plate 11 and a first reflective layer 12 that reflects radiant heat, which is formed on at least one surface of the first electrically insulating plate 11, i.e., on the upper surface (one surface) of the first electrically insulating plate 11 in Fig. 2. Although not limited thereto, it is more preferable that the first reflective layer 12 of the first radiant heat reflecting plate 7 faces the first electrically insulating substrate 2, and it is even more preferable that the first reflective layer 12 is formed on both surfaces of the first electrically insulating substrate 2.

[0033] The first reflective layer 12 has an electrical insulating portion 13 surrounding the outer periphery of the thermoelectric conversion elements 4a, 4b at a position spaced outward from the outer edge of the independent holes 10 as shown in Fig. 4. Therefore, the first reflective layer 12 is disposed so as to be in contact with the thermoelectric conversion elements 4a, 4b. The electrical insulating portion 13 may be formed in a concave shape such as a groove as shown in Fig. 2, or may be formed in a convex shape by using an electrical insulating material such as rubber or resin, thereby electrically insulating the thermoelectric conversion elements 4a, 4b from the first reflective layer 12.

[0034] As another embodiment of the electrical insulating portion 13A of the first reflective layer 12A, for example, as shown in FIG. 5, the electrical insulating portion 13A can be formed in a lattice-like arrangement so as to electrically insulate adjacent independent holes 10, 10 (multiple thermoelectric conversion elements 4a, 4b) from each other.

[0035] 1 and 2 is configured as a single first radiant heat reflecting plate 7, but is not limited thereto, and the radiant heat reflecting member may be configured as a plurality of first radiant heat reflecting plates 7. By installing a plurality of first radiant heat reflecting plates 7 using the space from the high temperature side to the low temperature side, a more excellent radiation suppression effect can be obtained.

[0036] When the first reflective layers 12B, 12C are formed on both sides of the first electrically insulating plate 11, it is preferable to have the first reflective layers 12B, 12C having electrically insulating portions 13B, 13C of different shapes formed thereon. As shown in Fig. 6(a), even if radiant heat (thin black arrow H) penetrates (thin black arrow P) the electrically insulating portion 13B (or the electrically insulating portion 13C) of one of the first reflective layers 12B, 12C, it is reflected (open arrow R) by the other first reflective layer 12C, 12B, so that a higher radiation suppression effect can be obtained. Figure 6(a) shows a case where a single first electrically insulating plate 11 has first reflective layers 12B, 12C with electrically insulating portions 13B, 13C of different shapes formed on both sides, but even when the radiant heat reflecting member has multiple first radiant heat reflecting plates 7, 7D having first reflective layers 12, 12D on one side of the first electrically insulating plates 11, 11D as shown in Figure 6(b), the same effect can be obtained by having the respective electrical insulating portions 13, 13D have different shapes.

[0037] A radiant heat reflecting member constituted by at least one first radiant heat reflecting plate 7 is preferably located closer to the first electrically insulating substrate 2 than the center position in the height direction of the thermoelectric conversion element 4 (center line C in the height direction), as shown in Fig. 2. By positioning the first radiant heat reflecting plate 7 (particularly the first reflective layer 12) closer to the first electrically insulating substrate 2 than the center position in the height direction of the thermoelectric conversion element 4 (center line C in the height direction), a sufficient temperature gradient from high to low temperatures can be obtained in the thermoelectric conversion element 4, and the thermoelectric performance as designed can be obtained.

[0038] Although not shown, one or more spacer members made of an electrically insulating material may be disposed between the second electrically insulating substrate 3 and the first radiant heat reflector 7. The spacer members may be disposed continuously (for example, a ring-shaped member) or in dots (multiple block-shaped members arranged at equal intervals) along the contour of the edge portion of the first radiant heat reflector 7. In addition, when two or more first radiant heat reflectors 7 are disposed, one or more spacer members made of an electrically insulating material may also be disposed between the respective first radiant heat reflectors 7.

[0039] The first electrically insulating plate 11 is required to have electrical insulation, like the first electrically insulating substrate 2 and the second electrically insulating substrate 3. However, it is preferable to use a material with low thermal conductivity in order to make it difficult for heat to be transferred from the high temperature side to the low temperature side in the region (space) between the thermoelectric conversion elements 4, 4. In particular, the thermal conductivity of the first electrically insulating plate 11 is preferably smaller than that of the thermoelectric conversion elements 4a, 4b. In addition, the first electrically insulating plate 11 is preferably used as a base material for the first radiant heat reflector 7 in order to ensure the strength of the first radiant heat reflector 7. The thickness of the first electrically insulating plate 11 is preferably 0.1 to 0.5 mm. The material of the first electrically insulating plate 11 is not particularly limited, but for example, a glass substrate, a glass epoxy substrate, or the like can be used. In a transparent (translucent) substrate such as a glass substrate, the radiant heat (thin black arrow H) passes through (thin black arrow P) as shown in FIG. 6(a) and FIG. 6(b). On the other hand, in the case of a non-transparent (non-light-transmitting) substrate such as a glass epoxy substrate, as shown in Figures 6(c) and 6(d), the radiant heat (thin black arrow H) is absorbed (thick black arrow A) and / or radiated (dashed arrow E) and passes through by thermal transfer (thin black arrow P2), but it is possible to obtain the same effect as when the radiant heat (thin black arrow H) passes through a transparent substrate (thin black arrow P).

[0040] The outer area of ​​the first electrically insulating plate 11 is preferably the same as or larger than the outer area of ​​either of the first and second electrically insulating substrates 2, 3. By employing this configuration, heat transfer from the high temperature side to the low temperature side due to gas convection is effectively prevented in the region (space) between the thermoelectric conversion elements 4, 4.

[0041] The first reflective layer 12 is formed on at least one side of the first electrically insulating plate 11 in the area (space) between the thermoelectric conversion elements 4, 4 to reflect radiant heat transferred from the high temperature side and prevent it from being transferred to the low temperature side.

[0042] The material of the first reflective layer 12 is not particularly limited, but it is preferable that the first reflective layer 12 is made of a metal having a high optical reflectance, such as gold, silver, copper, aluminum, etc. The thickness of the first reflective layer 12 is preferably 0.1 to 100 μm.

[0043] Methods for forming the first reflective layer 12 on the first electrically insulating plate 11 include, for example, a method in which the first reflective layer 12 made of a metal foil such as gold, silver, copper, aluminum, etc. is formed on the surface of the first electrically insulating plate 11 by bonding or the like, but other known methods may also be adopted.

[0044] Moreover, the first reflective layer 12 is preferably formed by dry or wet plating.

[0045] <Second embodiment> Fig. 7 shows a thermoelectric conversion module 1A according to a second embodiment of the present invention, and is a cross-sectional view taken at the same position of the thermoelectric conversion module 1A as the position on line II of the thermoelectric conversion module 1 shown in Fig. 1. Note that the same reference numerals are used to denote the same components of the thermoelectric conversion module 1A of the second embodiment as those of the thermoelectric conversion module 1 of the first embodiment.

[0046] In the thermoelectric conversion module 1 of the first embodiment, the first radiant heat reflecting plate 7 has a first reflective layer 12 formed on at least one surface thereof for reflecting radiant heat, whereas in the thermoelectric conversion module 1A of the second embodiment, in addition to this, a second reflective layer 15 for reflecting radiant heat is formed on the rear side of the surface of the first radiant heat reflecting plate 7 on which the first reflective layer 12 is formed, and is disposed so as not to come into contact with the thermoelectric conversion elements 4. That is, in the thermoelectric conversion module 1A of the second embodiment, the first radiant heat reflecting plate 7 has, on both sides of the first electrically insulating plate 11, the first reflective layer 12 and the second reflective layer 15 for reflecting radiant heat, and is disposed so as not to come into contact with the thermoelectric conversion elements 4a, 4b.

[0047] Even in the case where the first reflective layer 12 and the second reflective layer 15 are provided, a higher radiation suppression effect can be obtained, as in the case where the first reflective layer 12 shown in FIG. 6 has an electrical insulating portion 13 of a different shape.

[0048] The second reflective layer 15 can be formed using the same method, material, and dimensions as the first reflective layer 12. The first reflective layer 12 and the second reflective layer 15 may be formed using different materials.

[0049] FIG. 7 shows a configuration in which the first reflective layer 12 is formed on the first electrically insulating substrate 2 side and the second reflective layer 15 is formed on the second electrically insulating substrate 3 side on both sides of the first electrically insulating plate 11, but this is not limited to the above, and the second reflective layer 15 may be formed on the first electrically insulating substrate 2 side and the first reflective layer 12 may be formed on the second electrically insulating substrate 3 side.

[0050] The radiant heat reflecting member, which is composed of at least one first radiant heat reflecting plate 7 having a first reflective layer 12 and a second reflective layer 15 on both sides, is preferably located closer to the first electrically insulating substrate 2 than the center position in the height direction (height direction center line C) of the thermoelectric conversion element 4. By positioning the first radiant heat reflecting plate 7 (particularly the first reflective layer 12 and the second reflective layer 15) closer to the first electrically insulating substrate 2 than the center position in the height direction (height direction center line C) of the thermoelectric conversion element 4, a sufficient temperature gradient from high to low temperatures can be obtained in the thermoelectric conversion element 4, and the thermoelectric performance as designed can be obtained.

[0051] <Third embodiment> Fig. 8 shows a thermoelectric conversion module 1B according to a third embodiment of the present invention, and is a cross-sectional view taken at the same position of the thermoelectric conversion module 1B as the position on line II of the thermoelectric conversion module 1 shown in Fig. 1. Note that the same reference numerals are used for the components of the thermoelectric conversion module 1B of the third embodiment when they are the same as those of the thermoelectric conversion module 1 of the first or second embodiment.

[0052] In the thermoelectric conversion module 1B of the third embodiment, the radiant heat reflecting member further includes, in addition to the first radiant heat reflecting plate 7 shown in the first embodiment, at least one second radiant heat reflecting plate 19 having a second electrically insulating plate 20 and a second reflecting layer 15 that reflects radiant heat and is formed on only one side or both sides of the second electrically insulating plate 20 and arranged so as not to contact the thermoelectric conversion elements 4a, 4b.

[0053] Even when the radiant heat reflecting member is composed of multiple radiant heat reflecting plates, namely, the first radiant heat reflecting plate 7 and the second radiant heat reflecting plate 19, a higher radiation suppression effect can be obtained, as in the case shown in FIG.

[0054] The second electrical insulating plate 20 may be formed using the same method, material, and dimensions as the first electrical insulating plate 11. Although not limited thereto, the outer area of ​​the second electrical insulating plate 20 is preferably the same as or larger than the outer area of ​​either of the first and second electrical insulating substrates 2, 3, similar to the first electrical insulating plate 11. Note that, similar to the first electrical insulating plate 11, the thermal conductivity of the second electrical insulating plate 20 is preferably smaller than the thermal conductivity of the thermoelectric conversion elements 4a, 4b in order to make it difficult for heat to be transferred from the high temperature side to the low temperature side in the region (space) between the thermoelectric conversion elements 4, 4.

[0055] The radiant heat reflecting member constituted by the first electrically insulating plate 11 and the second electrically insulating plate 20 is preferably located closer to the first electrically insulating substrate 2 than the center position in the height direction (height direction center line C) of the thermoelectric conversion element 4. By positioning the first radiant heat reflecting plate 7 (particularly the first reflective layer 12 and the second reflective layer 15) closer to the first electrically insulating substrate 2 than the center position in the height direction (height direction center line C) of the thermoelectric conversion element 4, a sufficient temperature gradient from high to low temperatures can be obtained in the thermoelectric conversion element 4, and the thermoelectric performance as designed can be obtained.

[0056] <Fourth embodiment> Fig. 9 shows a thermoelectric conversion module 1C according to a fourth embodiment of the present invention, and is a cross-sectional view taken at the same position of the thermoelectric conversion module 1C as the position on line II of the thermoelectric conversion module 1 shown in Fig. 1. Note that the same reference numerals are used for the components of the thermoelectric conversion module 1C of the fourth embodiment when they are the same as those of the thermoelectric conversion modules 1 of the first to third embodiments.

[0057] As shown in Figure 9, the thermoelectric conversion module 1C of the fourth embodiment is an example of a configuration that uses at least one first radiant heat reflector 7 that constitutes the thermoelectric conversion module 1 of the first embodiment (Figure 2), and further has a side radiant heat reflector 25 that is arranged so as to substantially surround the radiant heat reflecting member (one first radiant heat reflector 7 in Figure 9) and the second electrically insulating substrate 3.

[0058] The side radiant heat reflector 25 has a third electrically insulating plate 26 and a third reflecting layer 27 formed on one surface of the third electrically insulating plate 26 and reflecting radiant heat, and is disposed so that the other surface of the third electrically insulating plate 26 faces the side surface of the radiant heat reflecting member and the side surface of the second electrically insulating substrate 3. It is preferable that the side radiant heat reflector 25 completely surrounds the radiant heat reflecting member (one first radiant heat reflector 7 in FIG. 9) and the second electrically insulating substrate 3, but an actual thermoelectric conversion module 1C has structural constraints such as the need to provide the second connection wiring 6. Therefore, in a portion not subject to structural constraints, the side radiant heat reflector 25 may be one that substantially surrounds the radiant heat reflecting member and the second electrically insulating substrate 3. In addition, in this embodiment, an example has been shown in which a single first radiant heat reflecting plate 7 is used as the radiant heat reflecting member, but this configuration is not limited to this, and multiple first radiant heat reflecting plates 7, or a second radiant heat reflecting plate 19 may be used together with the first radiant heat reflecting plate 7.

[0059] The third electrical insulating plate 26 can be formed by the same method and made of the same material as the first electrical insulating plate 11, and the third reflective layer 27 can be formed by the same method and made of the same material as the first reflective layer 12. Like the first electrical insulating plate 11, the thermal conductivity of the third electrical insulating plate 26 is preferably smaller than the thermal conductivity of the thermoelectric conversion elements 4a, 4b in order to make it difficult for heat to be transferred from the high temperature side to the low temperature side in the region (space) between the thermoelectric conversion elements 4, 4.

[0060] <Method of manufacturing thermoelectric conversion module> Next, an example of a method for manufacturing the thermoelectric conversion module 1 according to the first embodiment of the present invention will be described below. [1] Preparation of the first electrically insulating substrate 2 and the second electrically insulating substrate 3 A first electrically insulating substrate 2 having a first connection wiring 5 formed thereon is fabricated by etching an alumina substrate with a copper foil laminated thereon. Similarly, a second electrically insulating substrate 3 having a second connection wiring 6 formed thereon is fabricated. [2] Fabrication of p-type thermoelectric conversion element 4a and n-type thermoelectric conversion element 4b Eight p-type thermoelectric conversion elements 4a and eight n-type thermoelectric conversion elements 4b having a rectangular parallelepiped shape with cross-sectional dimensions of 2 mm × 2 mm and height dimensions of 3 mm are cut out from a sintered body of p-type thermoelectric conversion material and n-type thermoelectric conversion material, and a first electrode 8 and a second electrode 9 made of Ni are formed by vapor deposition on both end faces of 2 mm × 2 mm of each of the cut-out elements 4a, 4b. [3] Preparation of radiant heat reflector 7 A first reflective layer 12 made of gold and having a thickness of about 1 μm is formed by plating on an electrically insulating board 11 made of a 0.2 mm thick copper-coated glass epoxy substrate as the radiant heat reflector 7. Then, a plurality of independent holes 10 having a size that allows the passage of eight p-type thermoelectric conversion elements 4a and eight n-type thermoelectric conversion elements 4b are formed by machining. [4] Assembly of thermoelectric conversion module 1 Eight p-type thermoelectric conversion elements 4a and eight n-type thermoelectric conversion elements 4b are arranged alternately at intervals on the second connection wiring 6 formed on the second electrically insulating substrate 3 so as to form a lattice shape as a whole, and the second electrode 9 formed on one end surface of each thermoelectric conversion element 4a, 4b and the second connection wiring 6 are joined using silver paste. Then, from the side of the first electrode 8 formed on the other end surface of the thermoelectric conversion element 4, the radiant heat reflector 7 is moved through toward the second electrically insulating substrate 3 with the independent holes 10 of the radiant heat reflector 7 aligned with all the thermoelectric conversion elements 4a, 4b, and placed at a position in contact with the second connection wiring 6 formed on the second electrically insulating substrate 3. Then, the first connection wiring 5 formed on the first electrically insulating substrate 2, the first electrode 8 formed on the other end surface of each thermoelectric conversion element 4a, 4b, and the first connection wiring 5 formed on the first electrically insulating substrate 2 are joined using silver paste to manufacture the thermoelectric conversion module 1.

[0061] Although the embodiment of the present invention has been described above, the present invention is not limited to the above embodiment, and includes all aspects encompassed by the concept of the present invention and the scope of the claims, and can be modified in various ways within the scope of the present invention. [Explanation of symbols]

[0062] 1 Thermoelectric conversion module 2. First electrically insulating substrate 3. Second electrically insulating substrate 4 Thermoelectric conversion element 4a p-type thermoelectric conversion element 4b n-type thermoelectric conversion element 5 First connection wire 6 Second connection wire 7 First radiant heat reflector 8 1st electrode 9 Second electrode 10 independent holes 11 First electrical insulating plate 12 1st reflective layer 13 Electrical insulation section 15 Second reflective layer 19 Second radiant heat reflector 20 Second electrical insulating plate 25 Side radiant heat reflector 26 Third Electrical Insulating Board 27 Third reflective layer

Claims

1. In an environment with temperature differences, a first electrically insulating substrate disposed on the high temperature side; a second electrically insulating substrate disposed substantially parallel to and at a lower temperature side of the first electrically insulating substrate at a distance therefrom; a plurality of thermoelectric conversion elements sandwiched between the first and second electrically insulating substrates; connection wiring disposed between the first electrically insulating substrate and the plurality of thermoelectric conversion elements and between the second electrically insulating substrate and the plurality of thermoelectric conversion elements, the connection wiring connecting the plurality of thermoelectric conversion elements; In a thermoelectric conversion module having a radiant heat reflecting member including at least one first radiant heat reflecting plate disposed between the first and second electrically insulating substrates and substantially parallel to the first and second electrically insulating substrates; the first radiant heat reflecting plate includes a first electrically insulating plate, a first reflecting layer formed on at least one surface of the first electrically insulating plate and disposed so as to be in contact with the thermoelectric conversion elements, the first reflecting layer reflecting radiant heat, and a plurality of independent holes each having a size allowing the passage of the plurality of thermoelectric conversion elements; The thermoelectric conversion module according to claim 1, wherein the first reflective layer has an electrical insulating portion that electrically insulates the plurality of thermoelectric conversion elements from one another.

2. The first radiant heat reflector includes: On both sides of the first electrical insulating plate, the first reflective layer; a second reflective layer that reflects radiant heat and is disposed so as not to come into contact with the thermoelectric conversion element; The thermoelectric conversion module according to claim 1 .

3. The radiant heat reflecting member is A second electrically insulating plate; a second reflective layer that reflects radiant heat and is formed on only one surface or both surfaces of the second electrically insulating plate and is disposed so as not to come into contact with the thermoelectric conversion elements; The thermoelectric conversion module according to claim 1 , further comprising at least one second radiant heat reflecting plate having a first radiant heat reflecting plate and a second radiant heat reflecting plate having a second radiant heat reflecting plate.

4. The thermoelectric conversion module according to claim 3 , wherein the outer area of ​​the first electrically insulating plate and the outer area of ​​the second electrically insulating plate are both the same as or larger than the outer area of ​​either the first electrically insulating substrate or the second electrically insulating substrate.

5. The thermoelectric conversion module according to claim 3 , wherein the thermal conductivity of the first electrical insulating plate and the second electrical insulating plate is both lower than the thermal conductivity of the thermoelectric conversion element.

6. The thermoelectric conversion module according to claim 2 , wherein the first reflective layer and the second reflective layer are both formed by dry plating or wet plating.

7. The thermoelectric conversion module according to claim 1 , further comprising a side radiant heat reflector disposed so as to substantially surround the radiant heat reflecting member and the second electrically insulating substrate.

8. The side radiant heat reflector is A third electrically insulating plate; a third reflective layer formed on one surface of the third electrically insulating plate and configured to reflect radiant heat; having The thermoelectric conversion module according to claim 7 , wherein the other surface of the third electrically insulating plate is disposed so as to face a side surface of the radiant heat reflecting member and a side surface of the second electrically insulating substrate.

9. The thermoelectric conversion module according to claim 8 , wherein the third electrical insulating plate has a thermal conductivity lower than a thermal conductivity of the thermoelectric conversion element.

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