JPH1117234A - Thermoelectric transducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To avoid cracking a device by mounting a thermal stress relaxing member slidably between an electrode and a thermoelectric transducer to allow this transducer and relaxing member to follow up the deformation due to the temp. difference between opposed substrates. SOLUTION: A thermal stress relaxing member 10 is bonded to a thermoelectric transducer 3. The member 10 is formed as a cone 11 to reduce a part near electrode 6 with a convex spherical part 12 formed at the top of the cone 11, spot facings 30 with concave spherical recesses 31 at their centers are formed into the opposed upper and lower electrodes 6, thus making the member 10 slidable between the electrode 6 and transducer 3. This avoids stressing the transducer 3 as the member 10 rotates around the spherical part 12 of the electrode 6 if the top and bottom relative center positions of the transducer 3 change due to the thermal deformation of a heat exchange board 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a thermoelectric converter.

[0002]

2. Description of the Related Art Conventionally, there is a thermoelectric converter which converts electric energy into heat using the Peltier effect and converts heat into electric energy using the Seebeck effect. This thermoelectric converter, as shown in FIGS. 10 and 11,
Two substantially flat heat exchange substrates 1 and 2 disposed so as to face each other, and a plurality of P-type semiconductors 4 and N-type semiconductors 5 arranged in parallel between the heat exchange substrates 1 and 2 And an electrode 6 attached to the heat exchange substrates 1 and 2 while connecting the P-type semiconductors 4 and the N-type semiconductors 5 of the thermoelectric conversion element 3 so as to be alternately arranged in series. Is provided.

The P-type semiconductor 4 and the N-type semiconductor 5 have a substantially rectangular parallelepiped shape made of heavy metal formed by sintering or the like, and the P-type semiconductor 4 and the N-type semiconductor 5 and the electrodes 6 and 6 are soldered. 7,
7 and so on. The electrodes 6 and 6 are fixed to the heat exchange substrates 1 and 2 with an adhesive or the like.

In general, as the heat exchange substrates 1 and 2, an alumina ceramic substrate having good insulation and good heat conductivity is used. Copper patterns fixed to the heat exchange substrates 1 and 2 are used as the electrodes 6 and 6.

[0005]

However, in the above-described conventional thermoelectric converter, stress is generated due to deformation caused by thermal expansion and contraction of the heat exchange substrates 1 and 2, which are vertically opposed to each other, and this thermal stress is repeated. As a result, as shown in FIG. 12, a crack A is generated from the side surface of the thermoelectric conversion element 3 near the outer periphery of the junction between the thermoelectric conversion element 3 and the electrode 6, and the crack A extends to break. There is a problem that the life of the thermoelectric converter is shortened.

As a patent application for solving the above problem, there is Japanese Patent Application Laid-Open No. 8-321636. However, since the relaxation member is attached to the bonding electrode by solder, a so-called ramen structure is formed. When the bonding electrode changes from the initial position due to thermal expansion and contraction of the substrate, it is inevitable that a moment acts on the structure in which the relaxation member and the thermoelectric conversion element are combined.

In Japanese Patent Application Laid-Open No. 8-204241,
Since the thermoelectric conversion element is directly joined to the electrode, the high-temperature side and the low-temperature side are close to each other, and this structure is easily affected by radiation, causing heat to flow backward and being inefficient.

The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to suppress the generation and extension of cracks in a thermoelectric conversion element due to thermal stress, to provide an excellent heat-resistant stress resistance. An object of the present invention is to provide a thermoelectric conversion device that can have a long life.

[0009]

In order to solve the above-mentioned problems, according to the present invention, there is provided a heat exchange substrate between a substantially flat heat exchange substrate disposed so as to face each other. A thermoelectric conversion element having at least one pair of a P-type semiconductor and an N-type semiconductor
And an N-type semiconductor are connected so that they are connected in series alternately and have electrodes attached to the heat exchange substrate. A thermal stress relaxation member is provided between the thermoelectric conversion elements in a slidable state.

According to the second aspect of the present invention, the thermal stress relaxation member is attached to the upper and lower sides of the thermoelectric conversion element and forms a convex spherical portion at the tip of the conical shape. A counterbore is formed and a concave spherical depression is formed in the center of the counterbore.

According to the third aspect of the present invention, the thermal stress relaxation member is formed such that the tip on the electrode side has a convex spherical shape, and the corresponding electrode has a concave spherical shape.

According to the fourth aspect of the present invention, at least one of the thermal stress relieving members has a convex triangular cross section, and the corresponding portion of the electrode has a concave triangular cross section.

According to the fifth aspect of the invention, at least one of the thermal stress relieving members has a convex quadrangular cross section, and the corresponding portion of the electrode has a concave quadrangular cross section.

According to the sixth aspect of the present invention, at least one of the thermal stress relieving members has a convex circular cross section, and the corresponding portion of the electrode has a concave circular cross section.

According to the present invention, an electric insulating layer is provided at a specific position of the thermal stress relaxation member on which the electrode slides.

According to the present invention, a through-hole in the same direction as the displacement direction of the thermoelectric conversion element and the thermal stress relaxation member is formed in the thermal stress relaxation member to serve as a guide portion, and the guide hole is formed in the adjacent thermal stress relaxation member. A shaft-shaped electric conduction part penetrating the part is formed.

According to the ninth aspect of the present invention, the cross-sectional shape of the guide portion and the shaft portion is circular. In the invention according to claim 10,
Two substantially plate-shaped heat exchange substrates arranged so as to face each other, and a thermoelectric conversion element having at least one pair of a P-type semiconductor and an N-type semiconductor which are arranged in parallel between the heat exchange substrates; A thermoelectric conversion device comprising: a P-type semiconductor and an N-type semiconductor of the thermoelectric conversion element, which are connected so as to be alternately connected in series and have electrodes attached to a heat exchange substrate. A stress relaxation member is attached, the first thermal stress relaxation member is fixed to the heat exchange substrate, and the adjacent second thermal stress relaxation member slidably abuts on the heat exchange substrate,
The first thermal stress relaxing member and the second thermal stress relaxing member are connected by a bendable or extendable electrode.

[0018]

1 and 2 show a first embodiment.
(And FIGS. 10 and 11). FIG. 1 is a cross-sectional view of a main part of the thermoelectric converter, and FIG. 2 is a cross-sectional view of a main part of the thermoelectric converter.

Members having the same basic functions as those described in the conventional example are denoted by the same reference numerals. The thermoelectric conversion device includes two heat exchange substrates 1 and 2, a thermoelectric conversion element 3 having a plurality of P-type semiconductors 4 and N-type semiconductors 5, and electrodes 6 attached to the heat exchange substrates 1 and 2. In the present embodiment, thermal stress relaxation members 10, 10 are slidably inserted between the thermoelectric conversion element 3 and the electrodes 6, 6.

FIG. 1 shows an upper half portion of the thermoelectric conversion element 3, and a thermal stress relaxation member 10 is joined to the thermoelectric conversion element 3. And the electrode 6 and the thermoelectric conversion element 3
The space is slidable. The thermal stress relaxation member 10 is a cone 11 or a cone 11 formed in a pyramid shape or the like.
The portion near the electrode 6 is narrowed. A convex spherical portion 12 is formed at the tip of the cone 11,
A conical counterbore 30 is formed in the corresponding upper and lower electrodes 6, and a concave spherical recess 31 is formed in the center of the counterbore 30. The opening angle of the counterbore 30 is larger than the cone angle of the cone 11, so that the rotation of the thermal stress relaxation member 10 is not hindered.

In the thermoelectric conversion device configured as described above, even if the upper and lower relative center positions of the thermoelectric conversion element 3 change due to deformation of the heat exchange substrates 1 and 2 due to heat, the thermal stress relaxation member 10 can be used. , 10 are the concave spherical parts 12, of the upper and lower electrodes 6, 6.
Since the thermoelectric conversion element 3 can be rotated about the center 12, no stress is applied to the thermoelectric conversion element 3.

In FIG. 2, a part of a sphere is used as the shape of the thermal stress relaxation member 10. Upper and lower heat exchange boards 1, 2
Thermoelectric conversion element 3 and thermal stress relaxation member 10
Can be rotated. In the configuration of FIG. 2, the contact area between the electrodes 6, 6 and the thermoelectric conversion element 3 can be increased via the thermal stress relaxation members 10, 10, and the electric resistance can be reduced.

In both of the embodiments shown in FIGS. 1 and 2, the thermal stress relaxation members 10, 10 are provided at both ends of the thermoelectric conversion element 3, so that the deformation caused by the temperature difference between the opposed heat exchange substrates 1, 2 can be prevented. On the other hand, the thermal stress relaxation members 10, 10 provided integrally at the upper and lower ends of the thermoelectric conversion element 3 are electrodes 6, 6, respectively.
, The occurrence of cracks in the thermoelectric conversion element 3 can be suppressed.

Next, a second embodiment will be described with reference to FIGS. 3 is a perspective view showing a main part of the thermoelectric converter, FIG. 4 is a perspective view showing a main part of the thermoelectric converter, FIG. 5 is a perspective view showing a main part of the thermoelectric converter, and FIG. It is a perspective view.

The second embodiment is effective when the directions of thermal expansion and contraction of the heat exchange substrates 1 and 2, that is, the directions of thermal stress applied to the thermoelectric conversion elements 3 can be assumed in advance (FIGS. 3 to 3). (Fig. 6).

First, as shown in FIG.
Thermal stress relaxation members 10, 10 are joined above and below,
The thermal stress relaxation members 10, 10 are formed in a rectangular cross section. The corresponding electrodes 6, 6 have rectangular grooves 35, 35, respectively.
Is formed. The longitudinal direction of the groove 35 is a relative displacement direction of the heat exchange substrates 1 and 2. With this configuration, even if the heat exchange boards 1 and 2 are displaced in opposite directions, the thermal stress relaxation members 10 and 10 slide in the grooves 35 and 35 of the electrodes 6 and 6, so that the thermoelectric conversion element 3 has No stress.

The vertical cross-sectional shapes of the thermal stress relaxation members 10, 10 and the electrodes 6, 6 are not limited to the rectangular shape shown in FIG.
A similar sliding movement is possible with the triangle shown in FIG.

As shown in FIG. 4, the electrode 6, 6 having a circular cross-sectional shape can be rotated in addition to the movement in the direction of the groove 35 so that the upper and lower heat exchange substrates 1, 2 can be deformed. Stress can be absorbed by sliding in two directions.

Further, in the example shown in FIG. 6, an electric insulating layer 37 is provided at the end 36 of the groove 35 formed in the electrodes 6 and 6, and the inside of the groove 35 is covered by the thermal stress relaxation member 10 (not shown). The function of sliding is added to the function of preventing the thermoelectric converter from overheating. When the temperature on the high temperature side of the thermoelectric converter increases and the deformation of either of the heat exchange substrates 1 and 2 increases due to thermal expansion,
When the thermoelectric conversion element 3 and the thermal stress relaxation member 10 move with respect to the groove 35 and the thermoelectric conversion element 3 and the thermal stress relaxation member 10 reach the electric insulating layer 37, the electrical connection is released, and the thermoelectric conversion element 3 has its original function. The effect of heat transfer stops, and excessive heat generation can be suppressed.

Thereafter, when the temperature decreases due to heat radiation from the heat exchange substrate 1 or 2, the thermoelectric conversion element 3 moves in the direction opposite to that at the time of temperature rise, and is electrically connected again to the normal thermoelectric conversion element 3. Function is exhibited.

In order to smooth these sliding movements,
It is desirable to form a chamfered or arc-shaped introduction part in the thermal stress relaxation members 10 and 10.

Next, a third embodiment will be described with reference to FIGS. 7 is a front view showing a main part of the thermoelectric converter, FIG. 8 is a front view showing a main part of the thermoelectric converter, and FIG. 9 is a front view showing a main part of the thermoelectric converter.

FIG. 7 shows that when the adjacent thermoelectric conversion elements 3 and 3 are electrically connected to each other, a bendable wire-shaped electrode 6 or an electrode 6 formed of a spring material such as a coil spring is subjected to thermal stress. It is attached to the relaxation members 10 and 10. Adjacent upper thermal stress relaxation members 10 and 10
One is fixed to the heat stress relaxation member 10, and the other is adjacent to the other under the heat stress relaxation member 10 is fixed to the heat exchange substrate 2, and the electrode 6 expands and contracts when thermal expansion and contraction occur. I do.

Next, the one shown in FIG. 8 is provided with a through-hole 13 in one of the adjacent thermal stress relaxation members 10, 10 to form a guide portion 14, and the other thermal stress relaxation member 10 forms a shaft-like electric power. The conductive portion 50 is formed to protrude as the electrode 6, and this electrode 6
Is slidably inserted into the guide portion 14. Guide part 1
The cross-sectional shape of the 4 and the shaft-shaped electric conduction portion 50 can be circular, rectangular, or the like. Guide section 1 for a circular cross section
4. Both the shaft-shaped electrodes 6 are easy to process.

As shown in FIG. 9, electric insulating portions 53 and 53 are formed at the end portion 51 and the base portion 52 of the shaft-shaped electric conducting portion 50 as the electrode 6 to prevent excessive temperature rise. Can also be added.

The third embodiment described here also has
As in the second embodiment, it is effective when the direction of movement of the thermoelectric conversion element 3 and the thermal stress relaxation members 10, 10 can be assumed in advance, and the connection direction of the electrode 6 is changed to the heat exchange substrate 1.2.
In the direction of displacement due to thermal expansion and contraction.

[0037]

According to the first aspect of the present invention, since the thermal stress relaxation members are provided at both ends of the thermoelectric conversion element, the thermoelectric conversion element and the thermoelectric conversion element are protected from deformation caused by a temperature difference between the opposing heat exchange substrates. Since the thermal stress relaxation member follows well, it is possible to suppress the occurrence of cracks in the thermoelectric conversion element.

According to the second aspect of the present invention, the thermoelectric conversion element can be freely disposed regardless of the moving direction of the thermoelectric conversion element and the thermal stress relaxation member. Can be increased. In addition, since the tip is a microsphere, processing is easy, and there is an effect that the electric resistance does not largely change by the rotation of the thermoelectric conversion element.

According to the third aspect of the present invention, since the thermal stress relaxation member has a large spherical shape, the contact area can be made larger and the electric resistance can be reduced as compared with the first aspect of the invention. .

According to the fourth aspect of the invention, when the direction in which the thermal stress is applied can be specified, the thermal stress relaxation member and the electrode are both formed in a triangular cross section, so that there is an effect that processing is easy. .

According to the fifth aspect of the present invention, when the direction in which the thermal stress is applied can be defined, the thermal stress relaxation member and the electrode are both advantageous in working surface, and the rectangular cross section has a larger contact area. Since it is possible to secure the electric loss, it is possible to suppress the electric loss.

According to the sixth aspect of the present invention, when the direction in which the thermal stress is applied can be defined, the thermal stress relieving member and the electrode are both advantageous in working surface and have a circular cross section, so that the thermoelectric conversion element and the electrode This has the effect of enabling rotation in the axial direction and increasing the degree of freedom in structural design.

According to the seventh aspect of the present invention, since an overheating prevention and self-recovery function are provided, it is not necessary to separately add an electric circuit protection function.

According to the eighth aspect of the present invention, since the guide portion and the axial electrode are provided on the thermal stress relaxation member, it is possible to suppress the stress in one direction in which the thermal stress acts.

According to the ninth aspect of the present invention, since the guide portion and the axial electrode are provided on the thermal stress relaxation member, it is possible to suppress the stress in one direction in which the thermal stress acts. In addition, since the cross-sectional shapes of the guide portion and the shaft-like electrode are circular, there is an effect that both the guide portion and the electrode can be easily processed.

According to the tenth aspect, the thermoelectric conversion element slides and the electrodes can bend or expand and contract in response to thermal expansion and thermal contraction of the heat exchange substrate. It has the effect of not applying stress.

[Brief description of the drawings]

FIG. 1 is a sectional view of a main part of a thermoelectric converter according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a main part of the thermoelectric converter according to the first embodiment;

FIG. 3 is a perspective view of a main part of a thermoelectric converter according to a second embodiment of the present invention.

FIG. 4 is a perspective view of a main part of the thermoelectric conversion device.

FIG. 5 is a perspective view of a main part of the thermoelectric converter of the above.

FIG. 6 is a perspective view of a main part of the thermoelectric converter according to the first embodiment;
(A) is a perspective view, (b) is a perspective view of an example in which an electric insulating layer is provided.

FIG. 7 is a front view of a thermoelectric converter according to a third embodiment.

FIG. 8 is a front view of the thermoelectric conversion device of the example provided with the above-described electric conduction portion.

FIG. 9 is a front view of the thermoelectric conversion device of the example provided with the above-described electric insulating portion.

FIG. 10 is a perspective view of a conventional thermoelectric converter.

FIG. 11 is a front view of the thermoelectric conversion device.

FIG. 12 is a front view of a main part of the above.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heat exchange board 2 Heat exchange board 3 Thermoelectric conversion element 4 P-type semiconductor 5 N-type semiconductor 6 Electrode 10 Thermal stress relaxation member 11 Conical part 12 Spherical part 13 Through hole 14 Guide part 30 Counterbore 31 Depression 35 Groove 36 End Part 37 electrical insulation layer 50 electrical conduction part 51 end part 52 root part 53 electrical insulation part

Claims (10)

[Claims] 1. A thermoelectric conversion device comprising: a substantially flat heat exchange substrate disposed so as to face each other; and at least one pair of a P-type semiconductor and an N-type semiconductor disposed between the heat exchange substrates and arranged in parallel. A thermoelectric conversion device comprising: an element; and an electrode attached to a heat exchange substrate while the P-type semiconductor and the N-type semiconductor of the thermoelectric conversion element are connected so as to be alternately connected in series. A thermoelectric conversion device characterized by providing a thermal stress relaxation member attached to both sides of the device and slidably interposed between the electrode and the thermoelectric conversion element. 2. The thermoelectric conversion device according to claim 1, wherein the thermal stress relaxation member is attached to the top and bottom of the thermoelectric conversion element and forms a convex spherical portion at the tip of a conical shape. A thermoelectric converter, wherein a conical counterbore is formed in an electrode and a concave spherical recess is formed in the center of the counterbore. 3. The thermoelectric conversion device according to claim 1, wherein the thermal stress relaxation member has an electrode-side tip formed in a convex spherical shape, and the corresponding electrode formed in a concave spherical shape. Electric conversion device. 4. The thermoelectric conversion device according to claim 1, wherein at least one of the thermal stress relaxation members has a convex triangular cross section and a corresponding portion of the electrode has a concave triangular cross section. Electric conversion device. 5. The thermoelectric conversion device according to claim 1, wherein at least one of the thermal stress relieving members has a convex quadrangular cross section and a corresponding portion of the electrode has a concave quadrangular cross section. Electric conversion device. 6. A thermoelectric conversion device according to claim 1, wherein at least one of the thermal stress relaxation members has a convex circular cross section and a corresponding portion of the electrode has a concave circular cross section. Electric conversion device. 7. The thermoelectric conversion device according to claim 4, wherein an electric insulating layer is provided at a specific position of the thermal stress relaxation member on which the electrode slides. 8. The thermoelectric conversion device according to claim 1, wherein a through hole in the same direction as the displacement direction of the thermoelectric conversion element and the thermal stress relaxation member is formed in the thermal stress relaxation member as a guide portion,
A thermoelectric converter, wherein a shaft-shaped electric conduction portion penetrating the guide portion is formed on an adjacent thermal stress relaxation member. 9. The thermoelectric converter according to claim 8, wherein the guide and the shaft have a circular cross section. 10. Two substantially flat heat exchange substrates disposed so as to face each other, and at least one pair of a P-type semiconductor and an N-type semiconductor provided between the heat exchange substrates and arranged in parallel. A thermoelectric conversion device comprising: a thermoelectric conversion device comprising: a thermoelectric conversion element, and a P-type semiconductor and an N-type semiconductor of the thermoelectric conversion element, which are connected so as to be alternately connected in series and an electrode attached to a heat exchange substrate. Attaching a thermal stress relaxation member to the thermoelectric conversion element, fixing the first thermal stress relaxation member to the heat exchange substrate,
The adjacent second thermal stress relaxation member is slidably abutted against the heat exchange substrate, and the first thermal stress relaxation member and the second thermal stress relaxation member are connected by a bendable or expandable electrode. Characteristic thermoelectric converter.