CN101515628B - Thermoelectric device and method for manufacturing same - Google Patents

Abstract

Provided are a thermoelectric device capable of improving power generation performance while maintaining hermeticity after application of a thermal cycle, and capable of simplification of structure and improvement of device productivity and reliability by reducing the number of articles, and a method of manufacturing the thermoelectric device. A thermoelectric device, comprising a metal substrate (2), a thermoelectric element (3) assembled on the central part of the surface of the metal substrate (2), a metal cover (4) for covering the upper surface and side surfaces of the thermoelectric element (3), and A joining metal member (5) provided to a peripheral portion of the surface of the metal substrate (2) to hermetically seal the space between the metal substrate (2) and the cover (4).

Description

Thermoelectric device and manufacturing method thereof

This application is a divisional application of the invention patent application submitted by the applicant on August 2, 2006, with the application number 200610110939.9 and the invention title "thermoelectric device and its manufacturing method"

(1) Technical field

The present invention relates to a thermoelectric device and a method of manufacturing the same, and more particularly, to a thermoelectric device for converting heat into electricity or converting electricity into heat and a method of manufacturing the same.

(2) Background technology

A thermoelectric device is a device utilizing thermoelectric effects such as the Thomson effect, the Peltier effect, and the Seebeck effect. As a device that has been mass-produced, a temperature adjustment unit for converting electricity into heat and the like can be cited. Furthermore, the development of, for example, generator units for generating electrical energy from waste heat is ongoing.

In order to promote the power generation efficiency of the thermoelectric device closer to that of the thermoelectric element itself, supplying heat to one end of the thermoelectric element and dissipating heat from the other end of the thermoelectric element must be smoothly performed. Therefore, a ceramic substrate excellent in heat conduction is used as an insulating substrate constituting a thermoelectric device. Then, the electrodes provided to the ends of the thermoelectric elements are composed of a material having a low resistance value.

Also, when a thermoelectric device is exposed to a high temperature of 200°C, it is required not only that members directly exposed to the heat are not damaged by the heat, but also that the thermoelectric element and electrodes electrically connected to the thermoelectric element should be hermetically sealed. This is because it should be prevented that the thermoelectric elements and electrodes are exposed to high temperature and oxidized thereby resulting in a decrease in power generation efficiency. As described above, in a thermoelectric device, a ceramic substrate is generally used as an insulating substrate, and the ceramic substrate and the case are hermetically sealed by brazing.

In a thermoelectric device, in order to increase the output of electromotive force that can be output to the outside, a plurality of thermoelectric elements are arranged on a substrate to be interposed between insulating substrates having electrodes, and are electrically connected in series and thermally connected in parallel. However, in some cases, individual thermoelectric elements vary in height. In this case, there may be a disadvantage that the heat absorbed from the high temperature side cannot be sufficiently supplied to the thermoelectric element or the like, and desired power generation performance cannot be obtained in some cases. Therefore, a thermoelectric device has been proposed in which an elastic conductive member is arranged on the other end surface of the thermoelectric element opposite to one end surface of the connection substrate and a cap-type electrode for covering the conductive member and the thermoelectric element is provided to prevent their movement (see Patent Document 1).

[Patent Document 1] Patent Application Specification (Open) 2005-64457

However, in the invention disclosed in Patent Document 1, it is considered that there is a case where improvement of the power generation performance of the thermoelectric device becomes difficult. More specifically, when the cap-shaped electrodes are provided, insulating plates each having a predetermined height on the substrate are respectively arranged between the thermoelectric elements to prevent the plurality of electrodes from contacting each other to generate a short circuit. When these insulating plates are arranged, the number of thermoelectric elements arranged on the substrate is limited, and the ratio of the thermoelectric elements per unit area of the substrate is reduced. Therefore, the unit output of the thermoelectric device cannot be enhanced, and power generation performance is lowered.

Also, since the thermoelectric device is exposed to high temperature during operation, the thermal expansion of the respective members constituting the thermoelectric device exceeds normal temperature conditions. At this time, the amount of deformation of each member is different due to the difference in linear expansion coefficient of each member and the temperature difference between the heat-absorbing side and the heat-radiating side. In particular, due to the large difference in linear expansion coefficient between the ceramic substrate and the case, the load applied to the brazed portion increases, fracture occurs, and the airtightness of the thermoelectric device decreases, reducing power generation performance.

Furthermore, the thermal resistance from the heat source to the thermoelectric element is affected by the type of components placed between the heat source and the thermoelectric element, the thickness of the components, and the mechanical contact between these components. In particular, since the influence of mechanical contact is significant, it is necessary to reduce the mechanical contact between the heat source and the thermoelectric element by reducing the number of items, and it is also necessary to improve the power generation performance by reducing the thermal resistance. For example, when the thickness of the external electrode for outputting the electromotive force from the thermoelectric device to the outside is thicker than the substrate and then a gap is created between the substrate of the thermoelectric device and the coolant, the thermal resistance between them increases and the power generation performance decreases .

Also, when the ceramic substrate is mounted to the cover and is in contact with the inner surface of the cover without a gap to obtain electrical insulation from the cover, a gap is generated between the inner surface of the cover and the ceramic substrate due to machining accuracy. Therefore, the air layer present in the gap causes heat transfer loss to the thermoelectric element. This heat transfer loss also occurs between the cap electrode and the ceramic substrate. These heat transfer losses lead to a reduction in power generation performance.

(3) Contents of the invention

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a device capable of improving power generation performance while maintaining hermetic sealing after application of a heat cycle and capable of achieving simplification of the structure and device productivity and reliability by reducing the number of items Improved thermoelectric devices and methods of manufacturing such thermoelectric devices.

According to a first aspect of the present invention, there is provided a thermoelectric device comprising a closed container in which an inner space is constituted by a metal member and a first major surface and a second major surface opposite to each other at a certain distance; formed on the first major surface Insulating layer on top; wiring layer provided on the surface of the insulating layer; a plurality of thermoelectric elements fixed to the wiring layer at one end to stand vertically and electrically connected; metal arranged on the other end of the thermoelectric element to electrically connect a plurality of thermoelectric elements a wire mesh; and an insulating member disposed between the metal wire mesh and the second major surface.

According to a second aspect of the present invention, there is provided a thermoelectric device comprising a metal substrate; a thermoelectric element mounted on a central portion of a surface of the substrate; a frame body bonded to a peripheral portion of the surface of the substrate to enclose the thermoelectric element inside; a wiring electrode connected to the thermoelectric element with the other end leading to the frame on the substrate surface joining the frame; and a cover arranged opposite to the substrate surface via the frame so that the cover, the substrate, and the frame seal the thermoelectric element.

According to a third aspect of the present invention, there is provided a thermoelectric device comprising a metal substrate; a thermoelectric element mounted on a surface of the substrate; a cover arranged opposite to the surface of the substrate via the thermoelectric element; a peripheral portion having one end bonded to the substrate to A frame body of a high heat-resistance formed portion that surrounds the periphery of the thermoelectric element and that has the other end joined to the peripheral portion of the cover.

According to a fourth aspect of the present invention, there is provided a method of manufacturing a thermoelectric device, comprising the steps of forming a wiring layer on a first major surface constituting a metal closed container via an insulating layer; bonding a thermoelectric element to the wiring layer via a bonding material the steps of; the step of assembling the metal mesh on the thermoelectric element; assembling the insulating member on the metal mesh to maintain the insulating member between the metal mesh and the second major surface constituting the metal closed container, and by means of welding A step of closing the metal closed container to hermetically seal the inner space formed in the metal closed container.

According to a fifth aspect of the present invention, there is provided a method of manufacturing a thermoelectric device, which includes the steps of assembling a thermoelectric element on a substrate; mounting a frame on a peripheral portion of the surface of the substrate; the step of spraying an insulating material formed on the sprayed layer on the inner surface of the cover; and arranging the cover so that the inner surface of the cover is opposite to the substrate surface so that the cover pushes the metal fine wire mesh to press the other electrodes of the thermoelectric element through the sprayed layer, and A step of hermetically sealing the thermoelectric element in a space surrounded by the substrate, the cover, and the frame by attaching the peripheral portion of the cover to the frame.

According to a sixth aspect of the present invention, there is provided a method of manufacturing a thermoelectric device, which includes the steps of forming lead-out wiring on the surface of a metal substrate from a central portion to a peripheral portion; bonding a frame body to the peripheral portion of the substrate surface to span the the step of drawing out wiring; the step of electrically connecting the thermoelectric element to the electrode constituted in the region of one end of the drawing wiring; and mounting the cover to the surface of the substrate via the frame, and sealing the thermoelectric element in the substrate, the frame, and the cover Steps in the enclosed space.

According to the present invention, it is possible to provide a thermoelectric device capable of improving power generation performance while maintaining airtightness after application of a thermal cycle, and also capable of simplifying the structure and improving device productivity and reliability by reducing the number of articles, and manufacturing of such a thermoelectric device method.

(4) Description of drawings

1 is a cross-sectional view of a thermoelectric device according to a first embodiment of the present invention;

2 is an explanatory diagram illustrating a method of manufacturing a thermoelectric device according to a first embodiment of the present invention;

3 is an explanatory diagram illustrating a method of manufacturing a thermoelectric device according to a first embodiment of the present invention;

4 is an explanatory diagram illustrating a method of manufacturing a thermoelectric device according to a first embodiment of the present invention;

5 is an explanatory diagram illustrating a method of manufacturing a thermoelectric device according to a first embodiment of the present invention;

6 is an explanatory diagram illustrating a method of manufacturing a thermoelectric device according to a first embodiment of the present invention;

7 is an explanatory diagram illustrating a method of manufacturing a thermoelectric device according to a first embodiment of the present invention;

8 is a cross-sectional view of a thermoelectric device according to a first variation of the first embodiment of the present invention;

9 is a cross-sectional view of a thermoelectric device according to a second variation of the first embodiment of the present invention;

10A to D are cross-sectional views of main steps of the thermoelectric device shown in FIG. 9;

11 is a cross-sectional view of a thermoelectric device according to a third variation of the first embodiment of the present invention;

12 is a cross-sectional view of a thermoelectric device according to a fourth variation of the first embodiment of the present invention;

Fig. 13A is a cross-sectional view of a thermoelectric device according to a fifth variation of the first embodiment of the present invention, and Fig. 13B is a plan view of the heat exchange sleeve viewed from the line B-B in the direction of the arrow in Fig. 13A;

14 is a cross-sectional view of another variation of the thermoelectric device according to the fifth variation of the first embodiment of the present invention;

15 is a cross-sectional view of a thermoelectric device according to a second embodiment of the present invention;

16 is an explanatory diagram illustrating a method of manufacturing a thermoelectric device according to a second embodiment of the present invention;

17 is an explanatory diagram illustrating a method of manufacturing a thermoelectric device according to a second embodiment of the present invention;

18 is an explanatory diagram illustrating a method of manufacturing a thermoelectric device according to a second embodiment of the present invention;

19 is an explanatory diagram illustrating a method of manufacturing a thermoelectric device according to a second embodiment of the present invention;

20 is an explanatory diagram illustrating a method of manufacturing a thermoelectric device according to a second embodiment of the present invention;

21 is an explanatory diagram illustrating a method of manufacturing a thermoelectric device according to a second embodiment of the present invention;

22 is an explanatory diagram illustrating a method of manufacturing a thermoelectric device according to a second embodiment of the present invention;

23 is an explanatory diagram illustrating a method of manufacturing a thermoelectric device according to a second embodiment of the present invention;

24 is a cross-sectional view of a thermoelectric device according to a first variation of the second embodiment of the present invention;

25 is a cross-sectional view of a thermoelectric device according to a second modification of the second embodiment of the present invention;

26 is a cross-sectional view of a thermoelectric device according to a third embodiment of the present invention;

27 (including 27A, 27B, 27C) is an explanatory diagram showing a method of manufacturing a metal fine wire mesh from a foil according to a fourth embodiment of the present invention;

FIG. 28 (including 28A, 28B) is an explanatory diagram showing another method of manufacturing a metal wire mesh from a foil according to the fourth embodiment of the present invention;

29 is a cross-sectional view showing a thermoelectric device according to a fifth embodiment of the present invention;

30 is an explanatory diagram illustrating a method of manufacturing a thermoelectric device according to a fifth embodiment of the present invention;

Figure 31 is a plan view of the main steps of the thermoelectric device shown in Figure 30;

32 is an explanatory diagram illustrating a method of manufacturing a thermoelectric device according to a fifth embodiment of the present invention;

Figure 33 is a plan view of the main steps of the thermoelectric device shown in Figure 32;

34 is an explanatory diagram illustrating a method of manufacturing a thermoelectric device according to a fifth embodiment of the present invention;

Figure 35 is a plan view of the main steps of the thermoelectric device shown in Figure 34;

36 is an explanatory diagram illustrating a method of manufacturing a thermoelectric device according to a fifth embodiment of the present invention;

37 is an explanatory diagram illustrating a method of manufacturing a thermoelectric device according to a fifth embodiment of the present invention;

38 is an explanatory diagram illustrating a method of manufacturing a thermoelectric device according to a fifth embodiment of the present invention;

39 is an explanatory diagram illustrating a method of manufacturing a thermoelectric device according to a fifth embodiment of the present invention;

Figure 40 is a side view of the thermoelectric device shown in Figure 29 as viewed from direction D;

Fig. 41 is a cross-sectional view of a variant thermoelectric device according to the fifth embodiment of the present invention;

42 is a cross-sectional view of a thermoelectric device according to a sixth embodiment of the present invention;

43A and B are explanatory diagrams illustrating a frame body according to a sixth embodiment of the present invention in an enlarged manner;

FIG. 44 is an explanatory view showing in an enlarged manner a joint portion between a cover and a frame in a sixth embodiment of the present invention;

45 is a cross-sectional view of a thermoelectric device according to a first variation of the sixth embodiment of the present invention;

Fig. 46 is an explanatory diagram illustrating a frame body according to a first modification of the sixth embodiment of the present invention

47 is an explanatory diagram illustrating a frame body according to a second modification of the sixth embodiment of the present invention;

Fig. 48 is an explanatory diagram of another variation of the second variation of the sixth embodiment of the present invention;

Fig. 49 is an explanatory diagram of yet another variation of the second variation of the sixth embodiment of the present invention.

(5) specific implementation

Various embodiments of the present invention will be described in detail with reference to the following drawings.

(first embodiment)

As shown in FIG. 1, a thermoelectric device (closed container) 1 according to a first embodiment of the present invention is made of a metal substrate 2 made of metal, and placed in the center of the surface of the metal substrate 2 (hereinafter referred to as "first main surface α"). The thermoelectric element 3 on the part, the cover 4 for covering the upper surface and the side surface of the thermoelectric element 3, and the joint metal member 5 made of metal that hermetically seals the metal substrate 2 and the cover 4 on the peripheral portion of the first major surface α constitute . More specifically, all members constituting the container (electrical heating device) 1, namely, the metal substrate 2, the metal cover 4, and the joining metal member 5 are made of metal.

An insulating layer 6 is provided in the central portion on the first major surface α, and a first conductive wiring layer 7 is formed on the insulating layer 6 . As the insulating layer 6, preferably, for example, a resin or a resin containing ceramic powder should be used. In the first embodiment, copper can be used specifically as the metal substrate 2 and the first wiring layer 7 , and epoxy resin containing ceramic powder can be used as the insulating layer 6 . The thermoelectric element 3 is bonded to the first wiring layer 7 via, for example, a bonding material 8 such as solder.

Metal fine wire mesh 9 as a mesh-like conductive member is arranged at the ends of thermoelectric elements 3 not bonded to first wiring layer 7 to spread over a pair of thermoelectric elements 3 . Specifically, a strip formed by netting Cu thin wires having a diameter of 0.6 mm and cutting to a predetermined length can be used as the metal fine wire mesh 9 .

Since the metal fine wire mesh 9 has elasticity in the thickness direction, this metal fine wire mesh 9 can absorb the height variation of the assembled thermoelectric element 3 . Therefore, the electrical connection between the thermoelectric element 3 and the second wiring layer 11 can be determined via the metal filament 9, and the step of selecting/inspecting each length of the thermoelectric element 3 can also be omitted.

The insulating member 10 is arranged on the metal fine wire mesh 9 . Second wiring layer 11 is formed on the surface (lower surface in FIG. 1 ) of insulating member 10 , and metal film 12 is provided on the entire back surface (upper surface in FIG. 1 ) of insulating member 10 . The metal film 12 contacts the surface of the cover 4 opposite to the first major surface α (hereinafter referred to as “second major surface β”). By interposing the insulating member 10 between the second wiring layer 11 and the metal film 12, the mechanical strength of the insulating member 10 can be increased. Also, since the metal film 12 is in contact with the second major surface β, heat absorption efficiency can be improved.

The cover 4 is composed of a metal such as Kovar, stainless steel (preferably SUS304), and is metallically joined to the metal substrate 2 via a joining metal member 5 . A metal foil such as nickel (Ni) foil or the like can be used as the joining metal member 5 . Unlike the ceramic substrates so far, both the metal substrate 2 and the cover 4 are made of metal. Therefore, the difference in linear expansion coefficient between the metal substrate 2 and the cover 4 can be reduced, and the stress generated in the joint portion between the two members following thermal cycles can be reduced while being able to maintain airtightness.

The wiring layer used in the first embodiment is obtained by forming a commercially available metal substrate into the shape of a metal substrate of a thermoelectric device. As a generally widely sold metal substrate, copper (Cu), aluminum (Al), or the like is used as the metal substrate 2 . Also, the first wiring layer 7 obtained by the patterned copper foil is pasted on the first major surface α of the metal substrate 2 by using an insulating epoxy adhesive containing a filler. In employing such commercial metal substrates, metallic bonding obtained by alloying by means of welding through nickel components is effective in bonding substrates to alloys such as Kovar, stainless steel, and the like. For this purpose, a frame-shaped nickel member having the same shape as the outer periphery of the metal substrate is used as the joint metal member 5, so that the joint metal member 5 can be disposed along the outer edge of the metal substrate from which the metal substrate 2 is exposed, at When the same material as that of the cover 4 can be used as the material of the metal substrate 2, the joining metal member 5 is not required.

Cover 4 is arranged to contact metal film 12 at its second major surface β and cover the upper and side surfaces of thermoelectric elements 3 , and is bonded to metal substrate 2 via bonding metal member 5 at its peripheral portion. Since the cover 4 and the metal substrate 2 are bonded together, the insulating member 10 (the second wiring layer 11) and the metal fine wire mesh 9 placed on the thermoelectric element 3 are held and sandwiched by the cover 4 and the metal substrate 2 so as to The longitudinal direction of the thermoelectric element 3, that is, the direction in which the electric current flows in response to the generation of electromotive force, applies pressure.

A part of the cover 4 that contacts the metal member 5 is formed in a flange shape. Laser welding is applied over the entire periphery to the end face portion where the end of the flange of the cover 4, the connection metal member 5 and the metal substrate 2 are laminated to join them by an alloy containing nickel in its composition.

In this way, the thermoelectric device 1 has an inner space surrounded by the metal substrate 2 and the cover 4, and this inner space serves as a closed container isolated from the outside. The inside of the closed container is set to a low-pressure atmosphere, making it difficult to deform and damage the closed container even when exposed to high temperatures. Each thermoelectric element 3 is hermetically sealed in a closed container maintaining a low-pressure atmosphere.

As the thermoelectric element 3, there are two types consisting of a p-type thermoelectric element 3a and an n-type thermoelectric element 3b. The plurality of p-type thermoelectric elements 3a and the plurality of n-type thermoelectric elements 3b are alternately electrically connected in series, and thermally aligned in parallel from the heat-absorbing side to the heat-radiating side.

In the thermoelectric element 3, the current generated in the p-type thermoelectric element 3a and the n-type thermoelectric element 3b when heat is applied is made to flow in a direction opposite to the direction of the thermal gradient. When the p-type thermoelectric element 3 a and the n-type thermoelectric element 3 b are electrically connected in series by the first wiring layer 7 and the second wiring layer 11 , the voltage of the electromotive force increases.

As an electrical series connection, for example, on the metal substrate 2, the p-type thermoelectric elements 3a and the n-type thermoelectric elements 3b are alternately connected in the row direction and the column direction, respectively, and in each row, a first wiring layer 7 is respectively connected to a pair of One end of the p-type thermoelectric element 3a and the n-type thermoelectric element 3b are in electrical contact. Then, one second wiring layer 11 is electrically contacted with the other end of a pair of adjacent p-type thermoelectric elements 3a and n-type thermoelectric elements 3b, and this pair of adjacent p-type thermoelectric elements 3a and n-type thermoelectric elements 3b are not separated. connected to the same first wiring layer 7. That is, the p-type thermoelectric elements 3a and n-type thermoelectric elements 3b located at the ends of each row are constructed in such a manner that adjacent thermoelectric elements in the column direction are electrically connected to each other through the first wiring layer 7 or the second wiring layer 11. touch. With such a configuration, electric current converted from heat alternately passes through the p-type thermoelectric element 3a and the n-type thermoelectric element 3b and is output from the external electrodes.

Via wiring 13 provided to pass through metal substrate 2 and insulating layer 6 is connected to metal layer 14 at a portion of metal substrate 2 exposed to the outside. Then, this metal layer 14 is connected to an external electrode 16 via a solder 15, so that the electromotive force generated in the thermoelectric element 3 is taken out to the outside.

Next, an example of a manufacturing method (assembling method) of the thermoelectric device 1 will be described below with reference to FIGS. 2 to 7 .

As shown in FIG. 2 , the insulating layer 6 on which the first wiring layer 7 is formed is bonded to the metal substrate 2 (first main surface α), and the via wiring 13 is also formed. The insulating layer 6 is not bonded to the entire surface of the first major surface α, but the insulating layer 6 is bonded to the central portion of the metal substrate 2 so that a region where the insulating layer 6 is not bonded exists in the periphery along the periphery of the metal substrate 2 part to secure a bonding area for bonding the cover 4 and the metal substrate 2 together.

As shown in FIG. 3 , on a predetermined portion of the first wiring layer 7 , a bonding material 8 is coated. For example, it is preferable to use solder as the bonding material 8 . However, the material is not particularly limited if advantages similar to those of the first embodiment can be obtained.

Then, as shown in FIG. 4, a plurality of thermoelectric elements 3a and 3b are placed on the position where the bonding material 8 is applied so as to be aligned with, for example, the above arrangement, and the thermoelectric elements 3a and 3b are respectively bonded to the first wiring layer. 7. For example, when solder is used as the bonding material 8, the first wiring layer 7 and the thermoelectric elements 3a and 3b are commonly bonded together in a reflow furnace, respectively.

As shown in FIG. 5, a metal fine wire mesh 9 is placed on the thermoelectric elements 3a and 3b so as to stretch over them (electrically connect them). At this step, the metal fine wire mesh 9 is not bonded to the thermoelectric element 3 but just placed thereon.

Then, the insulating film 10 having the second wiring layer 11 and the metal film 12 previously provided on its surface and back surface, respectively, is loaded on top of the metal fine wire mesh 9 which has been placed on the thermoelectric element 3 . As is clear from FIG. 6 , they are provided only in the range where the second wiring layer 11 contacts the metal fine wire mesh 9 . In this step, the insulating member 10 is not bonded to the metal fine-wire mesh 9 but merely placed on the metal fine-wire mesh 9 .

Then, as shown in FIG. 7 , the cover 4 is arranged so as to contact the metal film 12 on the insulating member 10 and cover the upper surface and side surfaces of the thermoelectric element 3 , and the side portion of the cover 4 is also placed around the metal substrate 2 On the surface portion, the peripheral surface portion is not bonded to the above-mentioned insulating layer 6 . Then, the cover 4 and the metal substrate 2 are bonded together via the bonding metal member 5 . In the first embodiment, SUS304 was used as the material of the cover 4 , and Ni was used as the material of the joining metal member 5 . However, the materials of the cover 4 and the joining member 5 are not limited to these materials if airtightness can be maintained.

By engaging the cover 4 and the engaging metal member 5 in this way, an internal space C1 in which the heating element 3 is placed is created therebetween. The internal space C1 is set to a low-pressure atmosphere by reducing the pressure from the atmospheric pressure by, for example, 0.07 MPa via the sealing hole 17 previously provided to the cover 4 . Also, the internal space C1 is made into a non-oxidizing atmosphere by filling nitrogen, argon, etc., and then the sealing hole 17 is fused by laser to hermetically seal the internal space. Accordingly, a thermoelectric device 1 having a hermetically sealed structure can be obtained. Then, an external electrode 16 that outputs electricity generated by the thermoelectric device 1 to the outside is mounted to a portion of the via wiring 13 . The via wiring 13 provided for the thermoelectric device 1 is not limited to one, and a plurality of via wirings may be provided.

In this way, since the metal cover 4 is bonded to the metal substrate 2 via the bonding metal member 5, the difference in coefficient of thermal expansion among the respective members constituting the case of the thermoelectric device can be reduced. Therefore, even when the thermoelectric device 1 is exposed to high temperature, the joint portion between the metal substrate 2 and the cover 4 is not damaged, and the airtightness is never lost. Accordingly, the power generation performance of the thermoelectric element 3 provided in the internal space C1 of the thermoelectric device 1 can be improved, the thermoelectric device 1 having excellent reliability can be realized, and the thermoelectric device 1 can be easily manufactured.

(first change)

Next, a first variation of the first embodiment will be described below. In the first embodiment and subsequent variations of the first embodiment, the same reference numerals are attached to the same components as those explained in the first embodiment, and thus repeated description of the same components will be omitted here.

The configuration of the first variation differs from that of the first embodiment in that the cover 4 is divided into the main body of the cover 4 and the frame body 4 a and the metal substrate 2 is bonded to the frame body 4 a. That is, the cover 4 is bonded to the peripheral portion of the surface of the metal substrate 2 via the bonding metal member 5 in the first embodiment, while the frame body 4 a is bonded to the peripheral portion of the back surface of the metal substrate 2 in the first variation.

The electrothermal device 1 generates electricity from the absorbed heat by using the thermoelectric element 3 . In order to increase the thermoelectric conversion efficiency by generating a larger output, it is necessary to arrange a large number of thermoelectric elements 3 per unit area on the first major surface α. However, when the cover 4 is bonded to the metal substrate 2 at the peripheral portion of the first major surface α, there needs to be a predetermined bonding area for bonding the cover 4 to the metal substrate 2, so that it is necessary to arrange the first major surface α of the thermoelectric elements 3. The surface area is reduced. Therefore, in the thermoelectric device 1 according to the first variation, the bonding area between the cover 4 and the metal substrate 2 can be sufficiently secured while improving the packaging efficiency of the thermoelectric elements 3 on the first main surface α.

More specifically, as shown in FIG. 8, the frame body 4a for covering the part of the side surface of the thermoelectric element 3 is formed as an extension around the back surface of the metal substrate 2, and the periphery of the frame body 4a and the back surface of the metal substrate 2 The parts are joined together via joining metal members 5 . Therefore, the bonding area with the frame body 4 a can be sufficiently secured on the back surface of the metal substrate 2 as compared with the first main surface α. The thickness of the metal substrate 2 in this bonding region (the peripheral portion of the back surface of the metal substrate 2 ) is set to be thinner than the central portion of the back surface of the metal substrate 2 . Therefore, the joining metal member 5 can be easily aligned without the frame body 4 a (joining region) protruding from the central portion of the back surface of the metal substrate 2 .

In this way, the frame body 4 a is bonded to the back surface of the metal substrate 2 . Therefore, the first major surface α can be effectively used as a mounting area for the thermoelectric elements 3 without providing a bonding area, and thus a greater number of thermoelectric elements 3 can be arrayed on the first major surface α. Accordingly, the power generation efficiency of the thermoelectric device 1 can be further improved while maintaining the airtightness.

(second change)

Next, a second variation of the first embodiment will be described below.

In the second variation, unlike the first embodiment, as shown in FIG. 9 , the configuration of via wiring 13 is different. More specifically, in the second variation, as shown in FIG. 10A , firstly, a via hole 13A is formed in the metal substrate 2 in advance to form the via wiring 13 . Then, as shown in FIG. 10B , an insulating material 13B is filled in the through hole 13A, plugging the through hole 13A previously formed in the metal substrate 2 . Then, the insulating layer 6 having the first wiring layer 7 is bonded on the first main surface α, and the insulating layer 13C and the metal layer 14 (both are not shown in FIG. 10 ) are bonded to the back surface of the metal substrate 2 . Accordingly, when viewed from the bottom (see FIG. 9 ), metal layer 14 , insulating layer 13C, metal substrate 2 , insulating layer 6 , and wiring layer 7 are sequentially formed.

In this case, as shown in FIG. 10C , via holes 13D respectively passing through the aforementioned layers are formed. For example, the through hole 13D may be formed by machining using a drill. The through hole 13D may also be formed by punching. As shown in FIG. 10D , via wiring 13 is formed along at least the inner wall of via hole 13D. For example, the via wiring 13 is formed by plating. Then, external electrodes 16 are joined to metal layer 14 via solder 15 .

Due to the adoption of such a method for manufacturing the via wiring 13 , the internal space C1 of the thermoelectric device 1 can be hermetically sealed and the power generation efficiency of the electric heating element 3 can be improved. Thereby, not only can the thermoelectric device 1 and its manufacturing method excellent in reliability be realized, but also the via wiring 13 can be manufactured simply without using a special jig or the like in the process of manufacturing the via wiring 13 .

(third change)

Next, a third variation of the first embodiment will be described below.

As shown in FIG. 11 , unlike the first embodiment, the third variation is different in the configuration of the via wiring 23 . First, the via hole 23A is first formed in the metal substrate 2 to form the via wiring 23 . This through hole 23A is formed such that its diameter on the back surface is opened larger than that on the surface (first main surface α) of the metal substrate 2 . Then, an insulating material 23B is filled in the through hole 23A to bury the through hole 23A previously formed in the metal substrate 2 . In this case, insulating material 23B is filled but via hole 23A is not completely buried, but a recess is formed when viewed from the back surface of metal substrate 2 .

Then, the insulating layer 6 having the first wiring layer 7 formed thereon is bonded to the surface of the metal substrate 2 , and a via hole 23C passing through each wiring layer other than the first wiring layer 7 is formed. For example, the through hole 23C is formed by processing using a drill. Also, the through hole 23C may be formed by punching.

Then, the via wiring 23 is formed on the inner wall of the via hole 23C while forming a stepped portion contacting the insulating material 23B, and being coplanar with the back surface of the metal substrate 2 . For example, the via wiring 23 and the stepped portion 23D may be formed by plating. Then, although not shown in FIG. 11 , external electrodes 16 are joined via solder 15 .

By adopting such a method of manufacturing the via wiring 23 , the internal space C1 of the thermoelectric device 1 can be hermetically sealed and the power generation efficiency of the electric heating element 3 can be improved. Accordingly, a highly reliable thermoelectric device 1 and a manufacturing method thereof can be realized, and the size of the stepped portion 23D to be formed can be freely determined in terms of design. More specifically, as shown in A in Fig. 11, since the distance between the step portion 23D and the metal substrate 2 can be freely determined, that is, the insulation distance, the insulation between the step portion 23D and the metal substrate 2 can be ensured more. . Also, since the area of the joint portion between the external electrode 16 and the stepped portion 23D can be maximized with respect to the insulation distance balance, the joint between the external electrode 16 and the stepped portion 23D can be strengthened more simply.

In a third variation, the through hole 23A is opened as a stepped hole. However, if the hole on the back surface of the metal substrate 2 is opened larger than the hole on the surface, that is, if the hole is opened so that the diameter decreases from the back surface of the metal substrate 2 to the surface, for example, any shape such as A hole such as a tapered hole.

Also, like the stepped portion 23D in the third variation, it is preferable from the aspect of installation that the stepped portion 23D constitutes a coplanar surface. However, it is not always required that the stepped portion 23D is formed as a coplanar surface. However, it is preferable not to interfere with the contact between the metal substrate 2 and the heat and cold sources.

(fourth change)

Next, a fourth variation of the first embodiment will be described below.

As shown in FIG. 12 , thermoelectric device 1 according to the fourth variation has such a feature that fins 2 a are provided to the back surface of metal substrate 2 . In the fourth variation, an easily processed metal is used as the metal substrate 2, and these ribs 2a can be produced by cutting, etching, etc. the back surface of the metal substrate 2.

In other words, the fins 2a having a high heat dissipation effect are provided to the back surface of the metal substrate 2, functioning as the heat dissipation side. Therefore, the heat dissipation efficiency of the thermoelectric device 1 can be improved, and the power generation efficiency of the thermoelectric element 3 can also be further improved. Accordingly, the power generation efficiency of the thermoelectric device 1 can be further improved.

Here, the fins 2 a are not manufactured by processing the back surface of the metal substrate 2 , but the ribs 2 a manufactured as separate bodies of the metal substrate 2 may be mounted on the back surface of the metal substrate 2 .

(fifth change)

Next, a fifth variation of the first embodiment will be described below.

As shown in FIGS. 13A and 13B , the thermoelectric device 1 according to the fifth variation is characterized in that the metal substrate 2 functions as a heat exchange jacket. Fig. 13B is a view showing, as a plan view, the heat exchange jacket 2b cut along line B-B in Fig. 13A.

More specifically, the heat exchange jacket function is constituted by providing flow channels 2c inside the metal substrate 2 of the thermoelectric device 1 to circulate the medium. In order to obtain uniform and high heat exchange efficiency, the flow channels 2c are arranged in a zigzag shape over the entire area of the metal substrate 2 except the connection area to the external electrode 16 . In the case where the substrate 2 is manufactured by pasting two substrates together and then the flow channel 2c is formed in at least one of the pasted substrates by processing, etching, etc., the metal substrate 2 can be simply provided with a heat exchange jacket function.

A heat exchange jacket having a high heat exchange effect is provided to the metal base plate 2 . Therefore, the heat exchange efficiency of the thermoelectric device 1 can be improved, and the power generation efficiency of the thermoelectric element 3 can also be improved. Accordingly, the power generation performance of the thermoelectric device 1 can be further improved.

Like the thermoelectric device 1 according to the fourth variation above, in the thermoelectric device 1 according to the fifth variation, the heat exchange jacket 2 b manufactured as a separate body of the metal substrate 2 can be mounted on the back surface of the metal substrate 2 . Also, as shown in Fig. 14, the ribs 2a described in the fourth variation may also be installed to increase the surface area.

(second embodiment)

Next, a second embodiment will be described below. In the second embodiment and each variation of the second embodiment, the same reference numerals are attached to the same components as those explained in the first embodiment, and thus repeated description of the same components will be omitted here.

As shown in FIG. 15, a thermoelectric device 31 according to a second embodiment of the present invention includes a substrate 32, a thermoelectric element 3 on the substrate 32, and a cover 34, and also includes a sprayed layer 35 formed to closely contact the inner surface of the insulating cover 4. .

The substrate 32 is composed of an insulating substrate 32 a , a metal film 32 b provided on the insulating substrate 32 , and a wiring layer 37 . Here, the surface of the substrate 32 refers to the surface on which the thermoelectric elements are mounted, and the back surface thereof refers to the surface on which the metal film 32b is provided. As the insulating substrate 32a, for example, in the second embodiment other than the ceramic plate shown in FIG. 15, a resin or a resin containing ceramic powder can be preferably used. Also, for example, the metal film 32b may be formed on the back surface of the insulating substrate 32a by soldering, sputtering, or the like. As the metal film 32b, for example, copper is preferably used. On the surface of the insulating substrate 32a, for example, the thermoelectric element 3 is bonded to the wiring layer 37 via a bonding material 8 such as solder.

As the thermoelectric element 3, there are two types consisting of a p-type thermoelectric element 3a and an n-type thermoelectric element 3b. The plurality of p-type thermoelectric elements 3a and the plurality of n-type thermoelectric elements 3b are alternately electrically connected in series, and thermally aligned in parallel from the heat-absorbing side to the heat-radiating side.

The cover 34 is made of metal such as Kovar, stainless steel (preferably SUS304), for example, the sprayed layer 35 is provided in close contact with the inner surface of the cover 34 . Here, the inner surface of the cover 34 refers to a surface opposite to the surface of the substrate 32 via the thermoelectric element 3 . The surface of the cover 34 that contacts the outside when the thermoelectric device 31 is completed is assumed to be the outer surface.

An insulating ceramic material is used as the sprayed layer 35 . As the ceramic material, white alumina, gray alumina, magnesia spinel, chromium oxide, zirconium, which have electrical insulating properties, wear resistance, and compatibility with, for example, Kovar, stainless steel constituting the cover 34 can be appropriately selected. Stone etc. and then spray. Here, on the inner surface of the cover 34 , the entire surface of the cover 34 can be set as the spraying range of the thermal spray layer 35 . However, the sprayed layer 35 must be formed to such an extent that the sprayed layer 35 covers at least the area where the thermoelectric element 3 is aligned.

The cover 34 is arranged at a position to cover the upper surfaces of the plurality of thermoelectric elements 3 and joined to the frame body 39 . When the cover 34 and the frame body 39 are engaged with each other, the metal fine wire mesh 9 placed on the thermoelectric element 3 is pressed tightly with the cover 34, the frame body 39 and the base plate 32, so as to be along the longitudinal direction of the thermoelectric element 3, that is, along the direction due to the generation of electromotive force. The direction of the induced current flow exerts pressure.

A part of the frame body 39 that contacts the cover 34 is shaped into a flange shape. The end surface portion of the cover 34 on which the flange end portion of the frame body 39 overlaps is welded over the entire periphery thereof by laser welding.

A metal fine wire mesh 9 serving as a mesh-like conductive member is arranged on the ends of the thermoelectric elements 3 , which is not bonded to the wiring layer 37 , to spread over a pair of thermoelectric elements 3 .

The frame body 39 is bonded to the insulating substrate 32a via the adhesive material 41 on the frame connection electrode 40 provided on the peripheral portion of the surface of the insulating substrate 32a. That is, the frame body 39 surrounds the thermoelectric element 3 and connects the substrate 32 and the cover 34 . As the binder material 41, for example, a brazing filler metal is preferably used.

In this way, the thermoelectric device 31 has its inner space surrounded by the substrate 32 , the cover 34 and the frame body 39 . This inner space constitutes a box-shaped structure airtight from the outside. The inside of the box-shaped structure is set to a low-pressure atmosphere, so that the box-shaped structure is hardly deformed and damaged even when exposed to high temperatures. Each thermoelectric element 3 is hermetically sealed in a box-like structure maintaining a low-pressure atmosphere.

The portion of the via wiring 42 provided to pass through the insulating substrate 32a exposed to the outside of the insulating substrate 32a is bonded to the external electrode 43 via a bonding material (not shown). Therefore, the electromotive force generated in the thermoelectric element 3 is taken out to the outside.

Next, an example of a manufacturing method (assembling method) of the thermoelectric device 31 will be described below with reference to FIGS. 16 to 23 .

As shown in FIG. 16, first, the substrate 32 in the thermoelectric device 31 other than the cover 34 is manufactured. A wiring layer 37 is bonded to the surface of the substrate 32 composed of the insulating substrate 32a and the metal film 32b, and the via wiring 42 and the external electrodes 43 are also formed. The wiring layer 37 is not bonded to the entire surface of the substrate 32, but is bonded to the central portion of the substrate 32, so that a region where the wiring layer 37 is not bonded exists in the peripheral portion along the periphery of the metal substrate 32, to ensure that the surface of the substrate 32 The upper joint area with the frame body 39. A peripheral portion of the substrate 32 is used for a bonding area between the frame body 39 and the substrate 32, and the frame connection electrode 40 is formed thereon.

As shown in FIG. 17 , the frame body 39 is bonded to the frame connection electrode 40 formed on the substrate 32 through an adhesive material 41 .

As shown in FIG. 18 , bonding material 8 is applied on a predetermined portion of wiring layer 37 . As the bonding material 8, for example, solder is preferably used. However, if an effect similar to that of Embodiment 2 can be obtained, the material is not particularly limited.

As shown in FIG. 19, for example, according to the alignment described in the first embodiment, a plurality of thermoelectric elements 3a, 3b are placed on the positions coated with the bonding material 8, and then the thermoelectric elements 3a, 3b are respectively bonded to Wiring layer 37. For example, when solder is used for the bonding material 8, the thermoelectric elements 3a, 3b are collectively bonded to the wiring layer 37, respectively, in a reflow oven.

Then, the cover 34 is manufactured. As shown in FIG. 20, the loading cover 34 has its outer surface facing downward (with its inner surface facing upward). The sealing hole 34a is formed in the cover 34 first.

Then, as shown in FIG. 21 , a sprayed layer 35 is formed on the inner surface of the cover 34 . As described above, for example, white alumina is preferably used as the sprayed layer 35 . But the material is not particularly limited if an effect similar to that of the second embodiment can be obtained.

As shown in FIG. 22, a heat-resistant adhesive 35a is applied on the sprayed layer 35, and then the metal fine wire mesh 9 as a conductive member is bonded thereto. In the second embodiment, an inorganic binder material is used as the heat-resistant binder 35a, which does not generate gas or the like even when the thermoelectric device 31 is used at a high temperature. The heat-resistant adhesive 35a is applied in a sufficient amount to temporarily fix the wire mesh 9. In addition, the portion coated with the heat-resistant adhesive 35 a swells to form unevenness on the sprayed layer 35 . In this case, since the metal fine wire mesh 9 is deformed along unevenness, such unevenness can be absorbed by the metal fine wire mesh 9 when the metal fine wire mesh 9 is brought into contact with the thermoelectric element 3 . Here, even when only the metal fine wire mesh 9 is placed on the predetermined portion of the sprayed layer 35 without using the heat-resistant adhesive 35a, advantages similar to those of the present embodiment can be obtained.

Then, the substrate 32 and the cover 34 manufactured separately in this manner are bonded together so that the surface of the substrate 32 is opposed to the inner surface of the cover 34 via the frame body 39 . In FIG. 23 , a case is assumed in which the sprayed layer 35 and the metal fine wire mesh 9 are bonded to each other without the heat-resistant adhesive 35 a in the manufacturing step of the cover 34 . In other words, the fine wire mesh 9 is simply placed on the sprayed layer 35 formed on the inner surface of the cover 34 so that the fine wire mesh 9 falls when the inner surface of the cover 34 is directed downward during bonding to the substrate 32 . To this end, the cover 34 and the frame body 39 are engaged with each other in such a manner that the substrate 32 is placed with the thermoelectric element 3 facing down, and then the substrate 32 is placed on the cover 34 .

On the contrary, when the metallic fine mesh 9 is fixed to the sprayed layer 35a by the heat-resistant adhesive 35a, the metallic fine mesh 9 does not fall. Therefore, unlike the above case, no special bonding procedure is required, and either one of the substrate 32 and the cover 34 can be bonded to the other.

In this way, since the substrate 32 and the cover 34 are bonded to each other such that the surface of the substrate 32 is opposed to the inner surface of the cover 34 via the frame body 39 , an internal space C2 in which the thermoelectric elements are aligned is created therebetween. By utilizing the sealing hole 34 a previously provided in the cover 34 , the inside of the internal space C2 is set to a low-pressure atmosphere. In the second embodiment, for example, the pressure is reduced by 0.07 MPa from the atmospheric pressure, or the atmosphere is set to a non-oxidizing atmosphere by filling nitrogen, argon, etc., and then the internal space C2 is hermetically sealed by sealing the hole 34a by laser fusion. Accordingly, a thermoelectric device 31 having a hermetically sealed structure can be obtained. In this case, the via wiring 42 provided for the thermoelectric device 31 is not limited to one, and a plurality of via wiring 42 may be provided.

According to the thermoelectric device 31 manufactured in this way, there is no need to provide cap electrodes and insulating plates, but only the sprayed layer 35 and the metal fine wire mesh 9 are provided between the inner surface of the cover 34 and the thermoelectric element 3 . Therefore, since a large number of thermoelectric elements 3 can be arranged on the surface of the substrate 32, the unit output can be increased, and the mechanical contact between the heat source and the thermoelectric elements can be reduced by reducing the number of items for lowering thermal resistance. Thereby, the thermoelectric device 31 capable of improving power generation performance can be realized, and at the same time, the thermoelectric device 31 can be manufactured at low cost and with high productivity.

(first change)

Next, a first variation of the second embodiment of the present invention will be described below.

In the second embodiment, the cover 34 and the frame body 39 are made of metal. The first variant differs from the second embodiment in that the base plate 32 also consists of metal and the cover 34 has a different shape. That is, the sprayed layer 35 in the second embodiment is provided to the thermoelectric device 1 in the first embodiment.

As shown in FIG. 24, a thermoelectric device 51 according to a first variation of the second embodiment includes a metal substrate 2, a thermoelectric element 3 placed on the surface of the metal substrate 2, and an upper wall having an inner surface opposite to the surface of the metal substrate 2 and A cover 24 coupled to the peripheral portion of the upper wall and bonded to the side wall of the peripheral portion of the metal substrate 2 . In addition, the thermoelectric device 51 also includes the sprayed layer 35 contacting the inner surface of the cover 24 , the electrodes contacting the thermoelectric element 3 and the metal wire mesh 9 contacting the sprayed layer 35 . The insulating layer 6 is provided on the central portion of the surface of the metal substrate 2 , and the conductive wiring layer 37 is placed on the insulating layer 6 .

The cover 24 in the first variation is identical in configuration to the cover 4 in the first embodiment. Therefore, there is no need to provide the frame body 39 to the peripheral portion of the surface of the metal substrate 2 in the second embodiment, so the number of items can be reduced. For example, the cover 24 in the first variation is made of Kovar or stainless steel, and the thickness of the member is set to 0.2 mm or less.

Also, the cover 24 is constituted by integrally forming the cover 34 and the frame body 39 in the second embodiment, and is metallically joined to the metal substrate 2 by laser welding. Here, for example, by putting a bonding metal member 5 such as nickel (Ni) foil or the like, bonding ability between the cover 24 and the metal substrate 2 can be improved.

Via wiring 13 provided through metal substrate 2 and insulating layer 6 is connected to metal layer 14 at a portion exposed to the outside of metal substrate 2 , and then metal layer 14 is connected to external electrode 16 via solder 15 . Therefore, the electromotive force generated in the thermoelectric element 3 can be picked up to the outside.

The metal substrate 2 and the cover 24 formed in this way are metallized to be bonded to each other, for example, by laser, whereby an internal space C2 in which the thermoelectric elements are aligned is created therebetween. The interior of the internal space C2 is set to a low-pressure atmosphere by using the sealing hole 4b previously provided in the cover 24, or the atmosphere is set to a non-oxidizing atmosphere by filling nitrogen, argon, etc., and then the internal space C2 is fused by using a laser. The sealing hole 4b is hermetically sealed. Therefore, it is possible to obtain the thermoelectric device 51 having a hermetic structure.

According to the thermoelectric device 51 manufactured in this way, since the cover 24 is formed to have the upper wall whose inner surface is opposite to the surface of the metal substrate 2 and the side coupled to the peripheral portion of the upper wall and bonded to the peripheral portion of the metal substrate 2 Wall structure, so the number of items can be reduced. Meanwhile, there is no need to provide cap electrodes and insulating plates, but only the sprayed layer 35 and the metal fine wire mesh 9 are provided between the inner surface of the cover 24 and the thermoelectric element 3 . Therefore, since a large number of thermoelectric elements 3 can be arranged on the surface of the substrate 32, the unit output can be increased, and the mechanical contact between the heat source and the thermoelectric elements can be reduced by reducing the number of items for lowering thermal resistance. Thus, the power generation performance supplied to the internal space C2 in the thermoelectric device 51 can be improved while reducing the number of items, and the thermoelectric device 51 with excellent reliability can be realized, and the thermoelectric device 51 can be manufactured at low cost and high productivity.

(second change)

Next, a second variation of the second embodiment of the present invention will be described below.

In the first variation, the cover 24 is joined to the peripheral portion via the metal joining member 5 on the surface of the metal substrate 2 . This second variation differs from this in that the cover is bonded to the peripheral portion on the back surface of the metal substrate 2 . That is, the sprayed layer 35 in the second embodiment is provided to the thermoelectric device 1 shown in the first variation of the first embodiment.

As shown in FIG. 25, the frame body 4a for covering the part of the side surface of the thermoelectric element 3 is constituted as an extension around the back surface of the metal substrate 2, and the frame body 4a and the peripheral portion of the back surface of the metal substrate 2 are connected via a joint metal member. 5 joined together. Therefore, a bonding area with the frame body 4 a can be sufficiently ensured on the back surface of the metal substrate 2 as compared with the surface of the metal substrate 2 . The thickness of the metal substrate 2 in this bonding region (the peripheral portion of the back surface of the metal substrate 2 ) is set to be thinner than the central portion of the back surface of the metal substrate 2 . Therefore, the joining metal member 5 can be easily aligned without the frame body 4 a (joining region) protruding from the central portion of the back surface of the metal substrate 2 . In addition, the sprayed layer 35 contacting the inner surface of the cover 4 , the metal fine wire mesh 9 and the sprayed layer 35 contacting the electrodes of the thermoelectric element 3 are provided.

In this way, the frame body 4 a is bonded to the back surface of the metal substrate 2 without providing a bonding region on the surface of the metal substrate 2 . Therefore, the surface of the metal substrate 2 can be effectively used as a mounting area for the thermoelectric elements 3, and thus a greater number of thermoelectric elements 3 can be arrayed. Meanwhile, there is no need to provide cap-shaped electrodes and insulating plates, but only the sprayed layer 35 and the metal fine wire mesh 9 are disposed between the inner surface of the cover 4 and the thermoelectric element 3 . Therefore, it is possible to increase the unit output and reduce the mechanical contact between the heat source and the thermoelectric element by reducing the number of items to lower the thermal resistance. Thus, the power generation performance supplied to the internal space C2 in the thermoelectric device 61 can be improved while reducing the number of items, and the thermoelectric device 61 with excellent reliability can be realized, and the thermoelectric device 61 can be manufactured at low cost and high productivity.

(third embodiment)

Next, a third embodiment will be described below. In the third embodiment, the same reference numerals are attached to the same components as those explained in the first embodiment, and thus repeated description of the same components will be omitted here.

Fig. 26 is a cross-sectional view of the thermoelectric device 1 according to the third embodiment. The electromotive force generated from the thermoelectric element 3 is extracted to the outside of the thermoelectric device 1 through the via wiring 13 , the metal layer 14 , the solder 15 , and the external electrode 16 . In the third embodiment, the insulating material 18 insulating from the cooling medium is provided on the surface opposite to the surface of the solder 15 connected to the external electrodes 16 .

In each of the above-described embodiments, in the thermoelectric device 1 etc., the thickness of the metal substrate 2 etc. is reduced in the region of the via wiring 13 to include the external electrodes 16 etc. therein, and the region of the via wiring 13 is used to output electromotive force . The combined thickness obtained after laminating the via wiring 13 , the metal layer 14 , the solder 15 and the external electrodes 16 is the same as the thickness of the back surface of the metal substrate 2 .

In the third embodiment, the laminate thickness of the via wiring 13, the metal layer 14, the solder 15, the external electrode 16, and the insulating layer 18 provided in the region of the via wiring 13 that outputs the electromotive force becomes smaller than that of the metal substrate 2. Back surface thinness γ (becomes reduced when viewed from the surface of the metal substrate 2 ). That is, the distance from the back surface of the metal substrate 2 to the bonding surface between the via wiring 13 and the metal layer 14 is longer by γ than the distance from the insulating material 18 to between the via wiring 13 and the metal layer 14 .

In other words, since the lamination thickness of the via wiring 13 to the insulating material 18 becomes thick by providing, for example, the insulating material 18, it can be considered that when the cooling medium is brought into contact with the back surface of the metal substrate 2, since the wiring from the via hole 13 to the total thickness of the insulating material 18 to create a gap. However, with such an arrangement, it is possible to avoid an increase in thermal resistance due to a gap created between the cooling medium and the back surface of the metal substrate 2 . Therefore, heat dissipation from the thermoelectric device 1 can be efficiently performed, and thereby the power generation efficiency of the thermoelectric element 3 can be improved. Accordingly, the power generation performance of the thermoelectric device 1 can be further improved.

(fourth embodiment)

Next, a fourth embodiment will be described below. In the fourth embodiment, the same reference numerals are attached to the same components as those explained in the first embodiment, and thus repeated description of the same components will be omitted here.

In the fourth embodiment, there is a feature that the metal fine wire mesh 9 used in the above embodiments is wrapped with metal foil. The thin metal mesh 9a wrapped with such metal foil (hereinafter referred to as "the thin metal mesh 9a with foil") can be produced by, for example, the following method.

First, as shown in FIG. 27A, a cylindrical metal foil 9c formed by welding the metal foil 9b like a cylinder and the metal fine wire mesh 9 shown in FIG. 27B are prepared. Then, the foil-attached metal wire mesh 9a is manufactured by passing the metal wire mesh 9 through a cylindrical metal foil 9c, which is then cut to an appropriate size, as shown by the dotted line.

Also, the foil-attached metal fine wire mesh 9a can be manufactured by, for example, the method shown in FIG. 28 . That is, as shown in FIG. 28A, the metal fine wire mesh 9 is placed between two pieces of metal foil 9b, and then the metal foil 9b is welded to both sides of the metal fine wire mesh 9 (see FIG. 28B). Then, by cutting a plurality of welded foil-attached fine-wire meshes 9a into desired sizes indicated by dotted lines, desired foil-attached fine-wire meshes 9a are obtained.

Due to the use of such a foil-attached metal fine wire mesh 9a, the adhesiveness between the metal fine wire mesh 9 and the heating element 3 can be increased, and a reduction in thermal resistance can also be achieved. Also, since the metal fine wire mesh 9 is wrapped with the metal foil 9b, it is possible to prevent such a situation that the Cu filaments of the metal fine wire mesh 9 break and fall to make contact with the first wiring layer 7 and the like and produce a short circuit, thereby making it possible to An improvement in power generation performance is obtained. In addition, since the metal fine wire mesh 9a with foil can be received and handled in the process of manufacturing the thermoelectric device 1, etc., the step of placing the metal fine wire mesh 9 on the thermoelectric element 3 can be automated, and the thermoelectric device can also be improved. 1 productivity etc.

(fifth embodiment)

Next, a fifth embodiment will be described below. In the fifth embodiment, the same reference numerals are attached to the same components as those explained in the first embodiment, and thus repeated description of the same components will be omitted here.

As shown in FIG. 29, a thermoelectric device 71 according to a fifth embodiment of the present invention includes a metal substrate 72, a thermoelectric element 3 placed on a central portion of the surface of the metal substrate 72, and bonded to a peripheral portion of the surface of the substrate 72 to surround the thermoelectric element 3. The frame body 74 to the inside thereof, one end is electrically connected to the thermoelectric element 3 on the surface of the substrate 72 and the other end is connected to the lead wiring 75 of the external electrode extending from the frame body 74 to the outside, arranged so as to face the surface of the substrate 72 And the cover 76 of the thermoelectric element 3 is sealed in the space formed by this cover 76 , the substrate 72 and the frame body 74 .

A first insulating film 77 is provided on the surface of the metal substrate 72 , and a conductive electrode 78 is placed on a central portion of the first insulating film 77 . As the first insulating film 77, preferably, a resin or a resin containing ceramic powder should be used. In the fifth embodiment, copper can be used specifically as the metal substrate 72 and the first electrode 78 , and epoxy resin containing ceramic powder can be used as the first insulating film 77 . The thermoelectric element 3 is joined to the first electrode 78 via a joining material 79 such as solder, for example.

The insulating substrate 80 is arranged at the end of the thermoelectric element 3 not joined to the first electrode 78 . The second electrode 81 is formed on the surface (lower surface in FIG. 29 ) of the insulating substrate 80 across the pair of electrode elements 3 . Metal film 82 is provided on the entire area of the back surface (upper surface in FIG. 29 ) of insulating substrate 80 . Since the structure in which the insulating substrate 80 is placed between the second electrode 81 and the metal film 82 is adopted, the mechanical strength of the insulating substrate 80 can be increased, and also the contact between the metal film 82 and the cover 76 which is exposed to the outside can be reduced. thermal resistance. Thereby, the temperature difference between the upper end and the lower end of the thermoelectric element 3 can be increased, and the power generation capacity can be improved.

Frame body 74 is bonded to substrate 72 (metal foil 83 ) and cover 76 respectively at the peripheral portion of the surface of substrate 72 to surround thermoelectric element 3 therein, whereby thermoelectric device 71 is constituted as a box-shaped structure. The frame body 74 is made of, for example, metal such as Kovar, stainless steel (preferably SUS304), and by placing a nickel foil between the metal foil 83 and the frame body 74 and applying laser welding to them, the frame body Body 74 is metallically bonded to substrate 72 .

The lead wiring 75 passing under the frame body 74 is provided on the surface of the substrate 72 . The thermoelectric element 3 is electrically connected to an electrode formed in the region of one end of the lead wire 75 , the other end passing under the frame 74 extending to the outside of the frame 74 . The region of the other end serves as an external electrode from which the electromotive force generated in the thermoelectric element 3 is taken out to the outside of the thermoelectric device 71 . In this way, since the electromotive force is output to the outside of the thermoelectric device 71 without the via wiring, the resistance generated by the via wiring can be eliminated, whereby the power generation capability of the thermoelectric device 71 can be improved.

The cover 76 is made of, for example, metal such as Kovar, stainless steel (preferably SUS304), or the like. Since, in particular, the same material as that of the frame body 74 is used, the joint and airtightness between the cover 76 and the frame body 74 can be easily obtained. The cover 76 is arranged to cover the upper surface of the thermoelectric element 3 while being in contact with the metal film 82 , and is opposed to the surface of the substrate 72 via the frame body 74 . When the cover 76 and the frame body 74 are bonded together, the insulating substrate 80 (second electrode 81 ) placed on the thermoelectric element 3 is held and sandwiched by the cover 76 and the metal substrate 72 so that , that is, apply pressure along the direction in which the current flows when the electromotive force is generated.

In this way, the thermoelectric device 71 has an inner space surrounded by the substrate 72, the frame body 74, and the cover 76, and constitutes a box-shaped structure whose inner space is isolated from the outer area. The inside of the box-shaped structure is set to a low-pressure atmosphere so that the box-shaped structure is hardly deformed and damaged even when exposed to high temperature, or the inside of the box-shaped structure is hermetically sealed by setting to a non-oxidizing atmosphere.

Next, an example of a manufacturing method (assembling method) of the thermoelectric device 71 will be described below with reference to FIGS. 30 to 40 .

As shown in FIG. 30, a first insulating film 77 is provided on the surface of the metal substrate 72, and then a first electrode 78 is bonded thereto. At this time, the lead wiring 75 is bonded so that the ends of the substrate 72 and the first insulating film 77 coincide.

The lead wiring 75 passes under the frame body 74 in a part of the area where the substrate 72 (first insulating film 77) is connected to the frame body 74, and then extends from the inside of the frame body 74 to the outside, and an electric heating element is placed inside the frame body 74. 3. That is, as shown in FIG. 31 , as described above, the electrode region is on one end, the external electrode region is on the other end, and the region interposed between the electrode region and the external electrode region is provided as the lead wiring 75 . The frame body 74 is provided on a region interposed between the electrode region and the external electrode region, and in a narrow sense, for example, is used as a lead electrode. Similarly, in order to form the frame 74 horizontally on the substrate 72 (first insulating film 77 ), the same height as the lead wire 75 must be ensured also in a region where the frame 74 is connected but no lead wire is drawn therefrom. Therefore, as shown in FIGS. 31 and 32 , in the peripheral portion of the surface of the substrate 72 (first insulating film 77 ), the frame connecting metal foil 85 is formed in an area that connects the frame 74 but leads out the wiring 75 not derived from it. Here, in FIG. 30 , the surface of the substrate 72 refers to the upper surface to which the first insulating film 77 is bonded.

As shown in FIGS. 32 and 33, a prepreg 86 in which a metal foil 83 is formed on a second insulating film 84 is pasted to the region where the peripheral portion of the substrate 72 is connected to the frame body 74 and to the center of the surface of the substrate 72 on which the thermoelectric element 3 is mounted. part of the area. That is, the outer periphery of the frame connecting the metal foil 85 formed on the peripheral portion of the surface of the substrate 72 coincides with the outer periphery of the prepreg 86 , and the second insulating film 84 is bonded directly to the frame connecting metal foil 85 .

When the thermoelectric device 71 is working, the frame 74 is used as a heat transfer path connecting the heat-absorbing side and the heat-dissipating side, but the heat flowing inside the frame 74 has no effect on the power generation of the thermoelectric device 71 . As described above, in the fifth embodiment, the structure is adopted such that the second insulating film 84 having low thermal conductivity is laminated between the lead wire 75 , the frame connecting metal foil 85 and the metal foil 83 . With this arrangement, by reducing the amount of heat passing through the frame body 74 bonded to the metal foil 83 , the amount of heat supplied to the thermoelectric element 3 can be increased, and thus the power generation capacity of the thermoelectric device 71 can be improved.

Then, as shown in FIG. 34 , the prepreg 86 is removed to leave the area where the frame 74 is joined. As the removal method, a method of removing the metal foil by etching and a method of removing the insulating film by grinding can be considered. But the removal method is not limited to these. Thus, as is clear from FIG. 35 , a second insulating film 84 and a metal foil 83 (prepreg 86 ) are formed across the lead wiring 75 to surround the thermoelectric element 3 therein. In this case, since the second insulating film 84 is formed between the lead-out wiring 75 and the metal foil 83 , disadvantages such as a short circuit between the lead-out wiring 75 and the metal foil 83 and the like can be prevented.

Then, as shown in FIG. 36, the bonding material 79 is coated on the first electrode 78, and then the plurality of thermoelectric elements 3a and 3b are aligned according to the arrangement described in the first embodiment. Then, the first electrode 78 and the thermoelectric elements 3 a and 3 b are bonded to each other, respectively. In this case, for example, it is preferable to use solder as the bonding material 79 . However, the material is not particularly limited if an effect similar to that of the gas embodiment can be obtained. Also, for example, when solder is used as the bonding material 79, the first electrode 78 and the thermoelectric elements 3a, 3b are respectively commonly connected together in a reflow oven at a temperature corresponding to the type of solder used.

As shown in FIG. 37 , the frame body 74 is joined to the metal foil 83 by, for example, laser welding. Since the portion on which the lead-out wiring 75 is formed and the remaining portion have been set to be uniform in height, there is no need to change the height of the frame body 74 depending on the connection position, and levelness can also be easily ensured over the entire periphery. Also, laser welding can locally heat only the joint portion without heating the entire thermoelectric device 71 . Therefore, the frame body 74 can be joined by using the joining material 79 after the thermoelectric element 3 and the first electrode 78 are joined, so that the manufacture of the thermoelectric device 71 can be facilitated.

Then, as shown in FIG. 38 , the insulating substrate 80 that has been provided on the surface and the back surface of the second electrode 81 and the metal film 82 is put thereon. In particular, a second electrode 81 is placed across the thermoelectric elements 3a and 3b (connecting them electrically). Therefore, the plurality of p-type thermoelectric elements 3 a and the plurality of n-type thermoelectric elements 3 b are electrically connected in series alternately between the first electrode 78 and the second electrode 81 . At this step, the insulating substrate 80 is not connected to the thermoelectric element 3 but just placed thereon.

Then, as shown in FIG. 39, the cover 76 and the frame body 74 are bonded together by laser welding. As described above, since the frame body 74 is bonded to the metal foil 83 while maintaining a horizontal posture on the surface of the substrate 72 , the cover 76 can be bonded to the frame body 74 to maintain airtightness. In the fifth embodiment, SUS304 is used as the material of the cover 76 and the frame body 74 . However, the materials of the cover 76 and the frame body 74 are not limited to such materials if airtightness can be maintained.

In this way, since the cover 76 and the substrate 72 are bonded via the frame body 74 , an internal space C3 in which the thermoelectric elements are aligned is created therebetween. The internal space C3 is set to a low-pressure atmosphere by utilizing a sealing hole (not shown) previously provided in the cover 76 . Also, the internal space C3 is set to a non-oxidizing atmosphere by filling nitrogen, argon, or the like, and then the holes are sealed by laser fusion to hermetically seal the internal space C2. Accordingly, a thermoelectric device 71 having a hermetically sealed structure can be obtained.

In this way, the electromotive force generated by the thermoelectric element 3 is taken out to the outside not through the through-hole wiring but through the lead-out wiring 75 formed on the metal substrate 72 . Therefore, an increase in resistance caused by providing via holes can be prevented.

As shown in FIG. 40 depicted when the thermoelectric device 71 is viewed from the direction D indicated by the arrow in FIG. is connected to the substrate 72 but the lead-out wiring 75 is not formed. Thereby, the frame body 74 and the cover 76 are horizontally bonded to the substrate 72 respectively, and therefore, can be maintained airtight in the internal space C3.

Therefore, it is possible to reduce the resistance of the thermoelectric device with a simple arrangement, and it is also possible to efficiently extract generated electric energy to the outside. Also, the thermoelectric device 71 that improves the power generation performance of the thermoelectric element 3 provided in the internal space C3 of the thermoelectric device 71 and has excellent reliability can be realized and easily manufactured while maintaining airtightness.

(first change)

Next, a first variation of the fifth embodiment will be described below.

As shown in FIG. 41 , a thermoelectric device 71 according to the first variation is characterized in that ribs 2 a are provided on the back surface of a substrate 72 . As explained in the fifth embodiment, the electromotive force generated in the thermoelectric device 71 is output to the outside by using the lead wiring 75 formed on the surface of the metal substrate 72 . In other words, unlike the case of via wiring, there is no need to connect external electrodes to the back surface of the substrate 72, so the back surface of the substrate 72 can be kept in a planar state without unevenness.

Therefore, since the fins 2 a with good heat exchange effect are provided on the flat back surface of the substrate 72 , the heat exchange efficiency of the thermoelectric device 71 can be improved and the power generation efficiency of the thermoelectric element 3 can be improved. Therefore, the power generation performance of the thermoelectric device 71 can be further improved.

In the first variation, since a metal that is easily handled by processing can be used as the substrate 72, the ribs 2a can be produced by processing the back surface of the substrate 72 by means of cutting, etching, or the like. Also, the ribs 2 a are not manufactured by processing the back surface of the substrate 72 but are fixed to the back surface of the substrate 72 as separate bodies of the substrate 72 . Furthermore, as explained in the fifth variation of the first embodiment (see FIG. 13 ), the heat exchange jacket 2b may be installed or the fins 2a and the heat exchange jacket 2b may be used in combination.

(sixth embodiment)

Next, a sixth embodiment will be described below. In the sixth embodiment and various variations of the sixth embodiment, the same reference numerals are attached to the same components as those explained in the first embodiment, and thus repeated description of the same components will be omitted here. .

As shown in FIG. 42, a thermoelectric device 91 according to a sixth embodiment of the present invention includes a substrate 92, a thermoelectric element 3 mounted on the surface of the substrate 92, and a thermoelectric element 3 arranged opposite to the substrate 92 with the thermoelectric element 3 interposed therebetween. A cover 94 , a frame body 95 having a high thermal resistance formed portion, one end is joined to the peripheral portion of the substrate 92 to enclose the thermoelectric element 3 therein, and the other end is joined to the peripheral portion of the cover 94 .

The substrate 92 is composed of a first insulating substrate 92a and a metal foil 92b provided to the back surface of the first insulating substrate 92a. The first conductive electrode 96 is placed on the central portion of the surface of the first insulating substrate 92a. As the first insulating substrate 92a, as shown in FIG. 42, other than the ceramic substrate of the sixth embodiment, for example, resin or resin containing ceramic powder is preferably used. Metal foil 92b may be formed, for example, on the back surface of first insulating substrate 92a by bonding, plating, or the like. As the metal foil 92b, for example, copper is preferably used. The thermoelectric element 3 is joined to the first electrode 96 via, for example, a first joining material 97 such as solder.

The second insulating substrate 98 is arranged at the end portion of the thermoelectric element 3 not joined to the first electrode 96 . The second electrode 99 is formed on the surface (the lower surface in FIG. 42 ) of the second insulating substrate 98 across a pair of thermoelectric elements 3, and the metal film 100 is provided on the back surface (the upper surface in FIG. ) over the entire region. The metal film 100 may enhance the mechanical strength of the second insulating substrate 98 . In addition, the metal film 100 can improve the substantial contact of the second insulating substrate 98 with respect to the cover 94 and thereby reduce thermal resistance, thereby improving the heat exchange efficiency with the outside.

The cover 94 is made of metal such as Kovar, stainless steel (preferably SUS304), and placed in a position to cover the plurality of thermoelectric elements 3 while contacting the metal film 100 and being metallically bonded to the frame body 95 . When the cover 94 and the frame body 95 are bonded together, the second insulating substrate 98 (second electrode 99) placed on the thermoelectric element 3 is held and sandwiched by the cover 94, the frame body 95 and the substrate 92 so that the The longitudinal direction of the thermoelectric element 3, that is, the direction through which current flows in response to electromotive force generation, exerts pressure. Also, if the same metal as the frame body 95 is used as the cover 94, for example, the stress generated at the joint portion between the cover 94 and the frame body 95 can be reduced, and airtightness can be easily ensured.

The frame body 95 joins the substrate 92 and the cover 94 arranged at a position opposite to the substrate 92 at the peripheral portion of the surface of the substrate 92 to surround the thermoelectric element 3 inside and connect them. The thermoelectric device 91 is shaped into a box structure by a frame body 95 . The frame body 95 is composed of, for example, stainless steel (preferably SUS304) or the like, and is metallically bonded to the cover 94 and the base plate 82 via frame body bonding metal foil 101a and nickel foil 101b, respectively. As the frame bonding metal foil 101, metal foil such as copper foil can be used.

Also, the thermoelectric device 91 has a space inside by the substrate 92 and the cover 94, and this space can be hermetically sealed from the outside. Setting the inside of the box-shaped structure to a low-pressure atmosphere makes it difficult to deform and damage the box-shaped structure even when exposed to high temperatures. Each thermoelectric element 3 is hermetically sealed in a box-shaped structure in which a low-pressure atmosphere is maintained.

Meanwhile, "thermal resistance" means that the temperature rises when an electric power of 1W is applied, and the thermal resistance increases in proportion to the length (distance). Therefore, in the embodiment of the present invention, since the length of the frame body 95 is set to be longer than the gap between the substrate 92 and the cover 94, the thermal resistance of the frame body 95 and the heat flowing to the frame body increase, so that a larger Heat is supplied to the thermoelectric element 3 . As a result, improvement in power generation performance of the thermoelectric device 91 can be obtained.

The frame body 95 according to the sixth embodiment is not shaped to have a linear cross-sectional shape. In order to increase thermal resistance, as shown in FIG. 42 , the frame body 95 is formed by shaping the member so that the portion constituting the ridge and the portion constituting the root alternate laterally in cross-sectional form from the peripheral portion of the substrate 92 to the peripheral portion of the cover 94. Appear.

More specifically, in order to lengthen the frame body 95 between the base plate 92 and the cover 94, as shown in FIG. , and increase the number of arcs (folds) by reducing the radius of the bend to as small as possible. For example, in the case where the length from the surface of the frame bonding metal foil 101 contacting the frame 95 to the back surface of the cover 94 is set to 20 mm and the thickness of the frame 95 is set to 0.25 mm, plastic working can Bring the radius of the bend down to about 0.5mm. In this case, as shown in FIG. 43A , the number of folds by which the frame body 95 extends to the outside of the thermoelectric device 91 is nine, and the total length of the frame body 95 becomes about 31 mm.

Also, in the case shown in FIG. 43B , the total length of the frame body 95 becomes about 40 mm and is twice longer than the normal length from the frame body bonding metal foil 101 surface to the cover 94 back surface.

Since the thermal resistance increases in proportion to the length (distance), such thermal resistance also doubles when the total length is almost doubled. When the capability of installing the heat source of the thermoelectric device 91 is limited under such conditions, the ratio of the heat supplied to the thermoelectric element 3 to the heat flowing through the frame 95 ranges from 6:4 to 7.5:2.5. Therefore, since the amount of heat supplied to the thermoelectric element 3 is increased by 1.25 times, the power generation performance of the thermoelectric device 91 can be improved.

In addition, for example, a molded bellows can be used as the frame body 95 . Under the condition that while the tube made of the material constituting the frame body 95 passes through and is held in the mold in which folds are formed in advance, a large amount of fluid such as water, oil, etc. is passed through the tube to pass through the fluid pressure. The tube is expanded outwards to produce molded bellows by forming the straight tube through folds placed on the die. Also, a manufacturing method or the like may be employed in which folds are formed by applying drawing processing to push a tube made of the constituent frame 95 from the inside to the outside. For example, when the thermoelectric device 91 is a cylindrical structure, a molded bellows formed as above can be used as the frame body 95, and when a box-shaped structure is adopted, the bellows can be further formed into a rectangular shape according to plastic working. A processed molded bellows can be used as the frame body 95 . Also, the frame 95 can be formed by forming a flat plate into a corrugated plate, then bending the plate and welding the ends like rings.

The frame body 95 is bonded to the substrate 92 and the cover 94 in such a manner that one end and the other end bonded to the substrate 92 and the cover 94 are directed to the outside of the thermoelectric device 91 . In this case, description is sometimes given as if the substrate 92 and the frame body 95 are directly bonded to each other, but, as described above, the two members are actually bonded via the frame body bonding metal foil 101a and nickel foil 101b.

Then, by taking the joint portion between the cover 94 and the frame body 95 as an example, description will be made below. As shown in FIG. 44 , the frame body 95 has a second joining region 95d joined to the cover 94 at the other end 95c. The other end surface 95e of the other end 95c is arranged on the peripheral side of the cover 94, and the cover 94 and the frame body 95 are joined together via the second joining region 95d. One end of the frame body 95 bonded to the substrate 92 is similarly arranged and bonded to the substrate 92 .

Since the frame body 95 is arranged in such a direction as to the base plate 92 and the cover 94, their mutual bonding can be performed more easily.

The via wiring 102 provided through the substrate 92 and the first insulating substrate 92 a is connected to the external electrode 103 in a portion further exposed to the outside of the substrate 92 . Then, the external electrode 103 is connected to the external electrode 105 via the second bonding material 104 . Accordingly, the electromotive force generated in the thermoelectric element 3 can be output to the outside.

In this way, the members are joined so that the portion constituting the ridge and the portion constituting the root appear alternately in the cross-sectional form of the frame body 95 from the base plate 92 to the cover 94 . Therefore, since the overall length of the frame body 95 can be extended, the thermal resistance of the frame body 95 can be increased and larger heat can be conducted to the thermoelectric element 3 from the outside. As a result, power generation performance can be improved while maintaining airtight conditions, and an electrothermal device 91 with excellent reliability can be realized.

(first change)

Next, a first variation of the sixth embodiment will be described below.

As shown in FIG. 45 , the configuration of the first variation differs from the configuration shown in the sixth embodiment in the shape of the frame body 110 . In the sixth embodiment, the frame body 95 is formed by a shaping member such that a portion constituting a ridge and a portion constituting a root alternate laterally in cross-section from the peripheral portion of the base plate 92 to the peripheral portion of the cover 94 . Whereas in the first variation, the frame body 110 is constructed by alternately joining the back portion with an acute inner angle between the two sides and the bottom portion with an acute outer angle between the two sides in cross-section from the base plate 92 to the cover 94 .

In other words, as shown in FIGS. 45 and 46, assuming that a straight line drawn parallel to the joining surface between one constituent member 110a and the other constituent member 110a as constituent members of the frame body 110 is X (see FIG. 46), by this The angle between two sides formed by the straight line X and the straight line Y appearing on the surface of the constituent member 110a is Δ1. Here Δ1 is ninety degrees or less. In this case, a ridge formed toward the inside of the thermoelectric device 91 when the frame 110 is viewed from the outside of the thermoelectric device 91 (from position Z) is defined as a ridge, and conversely, a ridge formed toward the inside of the thermoelectric device 91 when the frame 110 is viewed from the outside is defined as a ridge. The ridge formed on the outside of 91 is defined as the bottom. The frame body 110 is constituted by joining the ridges and the bottom alternately from the base plate 92 to the cover 94 . Specifically, the frame body 110 is manufactured by laminating ring-shaped flat plates forming the central portion of the hole, and then alternately bonding the peripheral portion of the hole and the peripheral portion of the flat plate provided in the central portion of the flat plate.

More specifically, for example, assume that the length from the surface of the frame bonding metal foil 101 to the back surface of the cover 94 is 10 mm, and assume that the thickness of the frame 110 at the position where the frame 110 is provided is 0.25 mm. Also, when the frame body 110 is manufactured by laminating 8 flat plates (described later), the total length of the frame body 110 is 24 mm and the length becomes 2.4 times. As described above, since the thermal resistance is proportional to the length (distance), the thermal resistance becomes 2.4 times. Therefore, since the thermal resistance of the frame body 110 increases, the heat supplied to the thermoelectric element 3 is greater than the heat obtained so far, thereby improving the power generation performance of the thermoelectric device 91 .

Here, the frame body 110 is bonded to the substrate 92 and the cover 94 in such a manner that one end and the other end bonded to the substrate 92 and the cover 94 are directed to the outside of the thermoelectric device 91 .

In this way, the overall length of the frame 110 is extended by joining the ridge with an acute inner angle between the sides and the base with an acute outer angle between the sides in cross-section from the ridge 92 to the cover 94 . Thereby, thermal resistance can be increased and a larger amount of heat can also be conducted to the thermoelectric element 3 from the outside. As a result, power generation performance can be improved while maintaining airtight conditions, and an electrothermal device 91 with excellent reliability can be realized. Also, when the frame body 110 is manufactured by the above manufacturing method, the frame body 110 can be easily manufactured.

(second change)

Next, a second variation of the sixth embodiment will be described below.

In the second variation, when explained with reference to the frame body 110 shown in the first variation, the frame body 110 is composed of an increased number of constituent members, such as constituent assemblies 110a, 110b as shown in FIG. 47 . When the constituent components 110a, 110b are bonded together at the bonding surface 110c, for example, by laser welding, the thermal resistance of the frame body 110 increases, thereby improving the power generation performance of the thermoelectric device 91 . In this way, for example, constituent members constituting the frame body 110 are composed of metal such as stainless steel (preferably SUS304).

In this way, since the constituent members constituting the frame body 110 are welded to each other in such a manner that the joint portion is formed in a cross-sectional form except for the end portion of the frame body 110 including the cover 94 and the base plate 92 in any cross-sectional form, increased The thermal resistance of the frame body 110 . Likewise, when the frame body 110 and the substrate 92 are bonded through the metal foil used to bond the frame body 110 , thermal resistance also increases. As a result, the amount of heat supplied to the thermoelectric element 3 is greatly increased than usual, so that the power generation performance of the thermoelectric device 91 can be improved.

In the second variation, the description is made by using the frame body 110 shown in the first variation. For example, as shown in FIGS. 48 and 49 , when several constituent members constituting the frame body 110 are bonded, the thermal resistance of the frame body 110 can be increased. Furthermore, what has been described so far is the case where welding using, for example, laser light is performed. Furthermore, thermal resistance can be increased by applying, for example, soldering.

Presently, the present invention is not limited to their above embodiments, and the present invention can also be embodied by changing constituent members at the stage of implementation within the scope not departing from the original field. Also, various inventions can be produced by appropriately combining a plurality of constituent elements disclosed in the above-described embodiments. For example, several constituent elements may be deleted from all the constituent elements disclosed in the above-described embodiments. In addition, constituent elements spread across different embodiments may be combined as appropriate.

Claims (2)

1. A thermoelectric device, characterized in that, comprising: Wiring substrate; a plurality of thermoelectric elements having one end surface fixed to the wiring substrate so as to stand vertically; a plurality of electrode members arranged in contact with the other end faces of the plurality of thermoelectric elements; and a cover portion configured to be pressed from one end face of the thermoelectric element toward the other end face so as to hold a plurality of the thermoelectric elements and a plurality of the electrode members, The wiring board and the cover are soldered while maintaining relative positions to each other, The electrode member has a metal foil wrapping and holding a plurality of metal filaments. 2. The thermoelectric device of claim 1, wherein the electrode member is configured to connect at least two thermoelectric elements in series.

Images