JPH0951126A - Thermoelectric conversion device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an inexpensive themoelectric conversion device with improved manufacturing efficiency by using a required number of modules which are constituted by mounting a first electrode to one surface of a semiconductor layer and a second electrode to the other surface. SOLUTION: In a module M as a thermoelectric conversion element, a lower electrode 2 is formed on a lower insulation substrate 1 and a semiconductor layer 3 which is constituted of either thermoelectric conversion material of a P-type semiconductor material or an N-type semiconductor material is provided on the lower electrode 2. Then, an upper electrode 4 with a width for covering the upper surface is provided on the semiconductor layer 3 and an upper insulation substrate 5 is arranged on it. In the thermoelectric conversion element where the modules M are combined, a plurality of modules M are mounted to a conductor 7 with improved heat conductivity at a higher temperature having a fin 6. Then, a conductor 9 with improved heat conductivity at a lower temperature having a fin 8 is mounted to the other of each module M, is electrically connected in series by a lead wire 10, and an output terminal 11 is provided at the modules M at both edges, thus reducing the number of working processes and reducing cost.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoelectric conversion device,
The present invention relates to a thermoelectric converter that uses the Seebeck effect to generate electricity or a thermoelectric converter that uses the Peltier effect to cool, dehumidify, and heat.

[0002]

2. Description of the Related Art Thermoelectric conversion elements use the so-called Seebeck effect, in which heat energy is directly extracted as electrical energy by utilizing the temperature difference, and a temperature difference is applied to both sides of the element by passing an electric current. There is a method of using the so-called Peltier effect for cooling or heating.

At present, thermoelectric conversion elements are drawing attention as a cooling technology that does not use a cooling medium such as CFC against the background of environmental problems and energy resource problems. Has been done. Further, it has been attracting attention as an energy-saving technology such as exhaust heat recovery in factories and automobiles.

Conventionally, in order to obtain a certain high voltage from a limited heat source, a plurality of small chips made of thermoelectric material are used,
Thermoelectric converters that are thermally arranged in parallel and electrically connected in series have been developed and put into practical use.

FIG. 15 is a partial sectional view for explaining the conventional thermoelectric conversion device, and FIG. 16 is a perspective view in which the insulating substrates on both sides are omitted.

As shown in FIG. 15, a large number of lower electrodes 32 are formed on a lower insulating substrate 31 made of alumina or the like, and a P-type semiconductor layer 33 and an N-type semiconductor layer 34 are formed on each lower electrode 32. And are provided. An upper electrode 35 is provided so as to connect the P-type semiconductor layer 33 and the N-type semiconductor layer 34 of an adjacent chip, and an upper insulating substrate 36 made of alumina or the like is further arranged thereon to form a multi-chip / 1 module. It is in the form of.

The P-type semiconductor layer 33 and the N-type semiconductor layer 34
Are paired and are interposed in parallel between the lower insulating substrate 31 and the upper insulating substrate 36, and are electrically connected in series as shown in FIG. 16 to form a thermoelectric conversion device. . 37 in the drawing is an output terminal.

[0008]

By the way, since the thermoelectric conversion device of this structure uses a large number of small chip-shaped P-type semiconductor layers 33 and N-type semiconductor layers 34 (for example, about 100 to 300), they are used. Cutting process, electrodes 32, 35
In addition, the steps of arranging the semiconductor layers 33 and 34 in a predetermined order in the vertical and horizontal directions, the step of joining the respective parts, and the like are very complicated and the workability is poor, resulting in a high cost. Moreover, since there are many joining points, there is a problem in reliability.

An object of the present invention is to solve the above-mentioned drawbacks of the prior art, and to provide a thermoelectric conversion device which has high production efficiency and is inexpensive.

[0010]

In order to achieve the above object, the present invention provides a method in which a first electrode is attached to one surface of a semiconductor layer and a second electrode is attached to the other surface of the semiconductor layer.
It is characterized in that two independent modules are constructed and a required number, for example, one or a plurality of these modules are used and incorporated as a thermoelectric conversion device.

[0011]

According to the present invention, as described above, the first electrode is attached to one surface of the semiconductor layer and the second electrode is attached to the other surface of the semiconductor layer.
Since the electrodes are attached to form one independent module, it is easy to handle when assembled. Further, unlike the conventional case, it is not necessary to arrange the lower electrode, the P-type semiconductor layer, the N-type semiconductor layer, and the upper electrode, which are not joined together, in a predetermined order in the vertical and horizontal directions, and the working process is significantly reduced. The production efficiency is good and the cost can be reduced.

[0012]

Embodiments of the present invention will now be described with reference to the drawings.
FIG. 1 is a sectional view of a module according to the first embodiment, and FIG. 2 is a sectional view of a thermoelectric conversion device in which a plurality of the modules are combined.

The module M as a thermoelectric conversion element is shown in FIG.
, One lower electrode 2 having a relatively large area is formed on the lower insulating substrate 1 made of alumina or the like, and a P-type semiconductor material or an N-type semiconductor material is formed on the lower electrode 2. There is provided one semiconductor layer 3 having a relatively large area, which is composed of either one of the thermoelectric conversion materials (in this embodiment, is composed of a P-type semiconductor material). An upper electrode 4 having a relatively large area covering the upper surface of the semiconductor layer 3 is provided on the semiconductor layer 3, and an upper insulating substrate 5 made of alumina or the like is further arranged on the upper electrode 4 to form one chip. / 1 module form.

As shown in FIG. 2, the power conversion device combined with this module M uses the same thermoelectric conversion material having the structure shown in FIG. 1 for the high temperature side good conductor 7 having the fins 6 exposed to a high temperature atmosphere, for example. A plurality of modules M (using P-type semiconductor material in this embodiment) are attached. A low temperature side good thermal conductor 9 having a fin 8 exposed to a low temperature atmosphere is attached to the other side of each module M, and each module M is electrically connected in series by a lead wire 10 as shown in the figure, Output terminals 11 are provided on the modules M at both ends. The relatively large semiconductor layer 3 can be easily manufactured by a powder sintering method such as a plasma sintering method.

Although the insulating substrates 1 and 5 made of alumina or the like are used in this embodiment, it is also possible to use, for example, a metal plate having an electrically insulating thin film on the surface instead of alumina.

FIG. 3 is a sectional view of a thermoelectric conversion device for explaining the second embodiment of the present invention. In this example,
Lower electrode 2 and semiconductor layer 3 using P-type semiconductor material
And, one module M having a relatively large area including the upper electrode 4 is interposed between the high temperature side good thermal conductor 7 and the low temperature side good thermal conductor 9.

A casing 12 and a dispersion plate 13 interposed therein are arranged outside the low temperature side good heat conductor 9, and a heat transfer medium (for example, water or antifreeze liquid) is introduced from an inlet 12a of the casing 12. 14 is injected, the dispersion plate 13
The heat transfer medium 14 that has been dispersed in a plurality of locations and then collides with the low temperature side good heat conductor 9 and deprives the heat of the low temperature side good heat conductor 9 is discharged from the discharge port 12b of the casing 12 to the outside of the system. . The numeral 15 in the figure is a seal ring.

4 to 7 are views for explaining a third embodiment of the present invention, FIG. 4 is a sectional view of a semiconductor layer, FIG. 5 is a sectional view showing a state in which an electrode is in contact with the semiconductor layer, FIG. 6 is a partially enlarged sectional view showing the contact state between the semiconductor layer and the electrode,
FIG. 7 is a cross-sectional view of the thermoelectric conversion device.

In the case of this embodiment, a cylindrical or annular semiconductor layer 3 is used as shown in FIG.
The dish-shaped lower electrode 2 is fitted to the lower part of the plate, and the dish-shaped upper electrode 4 is fitted to the upper part of the semiconductor layer 3. The electrodes 2 and 4 are loosely fitted to the semiconductor layer 3 as shown in FIG. 6, and alleviate the stress generation of the semiconductor layer 3 due to the difference in thermal expansion coefficient between the electrodes 2 and 4 and the semiconductor layer 3. are doing.

Since the electrodes 2 and 4 and the semiconductor layer 3 are loosely fitted in this way, in order to ensure the connection between the electrodes 2 and 4 and the semiconductor layer 3, as shown in FIG. A spring member 17 such as a coil spring is interposed in a connecting rod 16 that is inserted between the good conductor 7 and the low temperature side good conductor 9, and the electrode 2,
4 and the semiconductor layer 3 are elastically in contact with each other.

FIG. 8 is a view for explaining the fourth embodiment of the present invention. In this embodiment, the inner surface of the dish-shaped electrodes 2, 4 contacting the semiconductor layer 3 is made of the same material as the semiconductor layer 3. The semiconductor thin film 18 is formed, and the electrodes 2 and 4 and the semiconductor layer 3 are formed.
The familiarity is good. If the dish-shaped electrodes 2 and 4 are used as in the third and fourth embodiments, the contact area with the semiconductor layer 3 is increased by the peripheral wall of the dish-shaped electrodes 2 and 4, and the heat transfer is improved. In the fourth embodiment, the semiconductor thin film 18 is formed on the inner surfaces of the dish-shaped electrodes 2, 4, but the semiconductor thin film 18 may be provided on the surface of the electrodes 2, 4 having a flat or other shape.

FIGS. 9 and 10 are views for explaining the fifth embodiment of the present invention. In the case of this embodiment, in order to suppress the chemical reaction between the electrodes 2 and 4 and the semiconductor layer 3, the two are suppressed. A barrier layer 19 made of, for example, nickel is formed,
Further, as shown in FIG. 10, the plate-shaped electrodes 2 and 4 are provided with a notch 20 having a notch shape, and due to the notch 20, the semiconductor layer 3 due to the difference in thermal expansion coefficient between the electrodes 2 and 4 and the semiconductor layer 3. It alleviates the stress generation.

Further, the entire module M except for a part of the electrodes 2 and 4 is protected by, for example, alumina spraying.
1 is formed, and the protection layer 21 prevents the module M from being oxidized and sublimated.

FIG. 11 is a diagram for explaining the sixth embodiment of the present invention. In this embodiment, electrodes 2 and 4 are formed at predetermined positions of the semiconductor layer 3 by thermal spraying or vapor deposition of metal.
At that time, the notches 2 are formed on the electrodes 2 and 4 by patterning.
0 is provided or a metal plate pre-patterned by a punching press or the like is fixed to the semiconductor layer, so that stress generation of the semiconductor layer 3 due to the difference in thermal expansion coefficient between the electrodes 2 and 4 and the semiconductor layer 3 is relaxed. are doing.

FIG. 12 is a view for explaining the seventh embodiment of the present invention. In the case of this embodiment, the semiconductor layer 3 is formed into a cylindrical shape or an annular shape, and is provided in the substantially central portions of the electrodes 2 and 4. The mountain-shaped protrusions 22 thus formed are fitted in the hollow portions of the semiconductor layer 3 to position the electrodes 2 and 4 with respect to the semiconductor layer 3.

FIG. 13 is a view for explaining the eighth embodiment of the present invention. In this embodiment, dish electrodes 2 and 4 having a diameter larger than that of the semiconductor layer 3 are used, and a peripheral wall 23 thereof is slightly formed. It is bent inward and elastically contacted with the peripheral surface of the semiconductor layer 3 to relieve stress generation of the semiconductor layer 3 due to the difference in thermal expansion coefficient between the electrodes 2 and 4 and the semiconductor layer 3 and to reduce the stress between the electrodes 2 and 4 and the semiconductor layer. 3 connection is secured.

FIG. 14 is a diagram for explaining the ninth embodiment of the present invention. In the case of this embodiment, a P-type module M and an N-type module in which electrodes 2 and 4 are attached to both surfaces of a semiconductor layer 3 are shown. M is connected in series by a lead wire 10.

[0028]

As described above, the present invention forms one independent module by attaching the first electrode to one surface of the semiconductor layer and the second electrode to the other surface of the semiconductor layer. Therefore, it is easy to handle. Further, unlike the conventional case, it is not necessary to arrange the lower electrode, the P-type semiconductor layer, the N-type semiconductor layer, and the upper electrode, which are not joined together, in a predetermined order in the vertical and horizontal directions, and the working process is significantly reduced. It has features such as good production efficiency and cost reduction.

[Brief description of drawings]

FIG. 1 is a sectional view of a module according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a thermoelectric conversion device in which the modules are combined.

FIG. 3 is a sectional view of a thermoelectric conversion device according to a second embodiment of the present invention.

FIG. 4 is a sectional view of a semiconductor layer according to a third exemplary embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a state where an electrode is in contact with the semiconductor layer.

FIG. 6 is a partially enlarged sectional view showing a contact state between the semiconductor layer and an electrode.

FIG. 7 is a sectional view of a thermoelectric conversion device according to the third embodiment.

FIG. 8 is a partially enlarged sectional view of an electrode according to a fourth embodiment of the present invention.

FIG. 9 is a sectional view of a thermoelectric conversion device according to a fifth embodiment of the present invention.

FIG. 10 is a plan view of an electrode used in the thermoelectric conversion device.

FIG. 11 is a plan view showing a state in which the electrodes of the thermoelectric conversion device according to the sixth embodiment of the present invention are sprayed.

FIG. 12 is a sectional view of a thermoelectric conversion device according to a seventh embodiment of the present invention.

FIG. 13 is a sectional view of a thermoelectric conversion device according to an eighth embodiment of the present invention.

FIG. 14 is a sectional view of a thermoelectric conversion device according to a ninth embodiment of the present invention.

FIG. 15 is a partial cross-sectional view of a conventional thermoelectric conversion device.

FIG. 16 is a perspective view of the thermoelectric conversion device with an insulating substrate removed.

[Explanation of symbols]

 1 Lower Insulation Substrate 2 Lower Electrode 3 Semiconductor Layer 4 Upper Electrode 5 Upper Insulation Substrate 6 Fin 7 High Temperature Side Good Heat Conductor 8 Fin 9 Low Temperature Side Good Heat Conductor 10 Lead Wire 11 Output Terminal 12 Casing 13 Dispersion Plate 14 Heat Transfer Medium 15 Seal Ring 16 Connecting rod 17 Spring member 18 Semiconductor thin film 19 Barrier layer 20 Notch 21 Protective film 22 Projection 23 Peripheral wall M module

Claims (7)

[Claims] 1. A first electrode is attached to one surface of a semiconductor layer, and a second electrode is attached to the other surface of the semiconductor layer.
A thermoelectric conversion device comprising two independent modules and using the required number of the modules. 2. The module according to claim 1, wherein a plurality of the modules are connected in series, and the first electrode group is arranged on a high temperature atmosphere side and the second electrode group is arranged on a low temperature atmosphere side. Characteristic thermoelectric conversion device. 3. The thermoelectric conversion device according to claim 1, wherein the thermoelectric conversion material is a P-type semiconductor material or an N-type semiconductor material. 4. The thermoelectric conversion device according to claim 1, wherein the electrode is shaped like a dish and is fitted to the semiconductor layer. 5. The thermoelectric conversion device according to claim 4, wherein the dish-shaped electrode is loosely fitted in the semiconductor layer. 6. The thermoelectric conversion device according to claim 1, wherein a semiconductor thin film made of the same material as the semiconductor layer is formed on a surface of the electrode in contact with the semiconductor layer. 7. The thermoelectric conversion device according to claim 1, wherein the electrode is provided with a notch for absorbing a difference in thermal expansion coefficient between the electrode and the semiconductor layer.