JPH0738157A - Thermoelectric conversion element - Google Patents

Abstract

PURPOSE:To enable a thermoelectric conversion element to be enhanced in strength, lessened in size, set high in space factor, and remarkably improved in usability by a method wherein either an N-type or a P-type semiconductor element is formed into a cylinder, and another rod-like semiconductor element, is put into the former cylindrical semiconductor element through the intermediary of an insulating layer. CONSTITUTION:A round rod-like N-type semiconductor element 2 is inserted into a cylirndrical N-type semiconductor element 1 in a telescopic manner, and an insulator layer 3 of flame spraying alumina film is interposed between the elements 1 and 2 to put them in one piece. Then, a PN junction electrode 4 is provided to the end of the assembly of integral structure by brazing or a diffusion process. By this setup, a thermoelectric conversion element of this constitution is higher in strength to loading weight than a conventional one of U-shaped structure, easily handled, lessened in size, excellent in space factor, and remarkably improved in usability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoelectric conversion element comprising a pair of n-type and p-type semiconductor elements and utilizing the thermoelectric effect of Seebeck effect and Peltier effect.

[0002]

2. Description of the Related Art Conventionally, various types of thermoelectric conversion elements of this type have been proposed, and examples thereof are shown in FIGS. 2 and 3 of the accompanying drawings. In the structure shown in FIG. 2, one ends of a rod-shaped n-type thermoelectric semiconductor element A and a p-type semiconductor element B are bonded to each other by a bonding electrode C, and electrodes D and E are provided at the other ends, respectively. Further, in FIG. 3, rod-shaped n-type thermoelectric semiconductor elements F and p are shown.
It is shown that one ends of the mold semiconductor elements G are bonded to each other. Both examples have a U-shaped structure. By the way, in the thermoelectric conversion element utilizing the Seebeck effect, by heating the high temperature side end portion where the pn junction is formed and cooling the leg side which becomes the low temperature side end portion, the high temperature side end portion and the low temperature side end portion are separated. The thermoelectromotive force is generated by the temperature difference. On the other hand, in the thermoelectric conversion element utilizing the Peltier effect, a positive voltage is applied to the leg side of the n-type semiconductor element and a negative voltage is applied to the leg side of the p-type semiconductor element. When a current is applied to the p-type semiconductor element, the pn junction absorbs heat and heat is generated in each leg. Conversely, when a current is passed from the p-type semiconductor element to the n-type semiconductor element, heat is generated at the pn junction, and the heat is absorbed by each leg.

[0003]

In such a conventional U-shaped thermoelectric conversion element, since one ends of the p-type and n-type semiconductor elements are joined, they are vulnerable to a lateral load, and the joint portion during handling. However, there is a problem that the p-type and n-type semiconductor elements are damaged or the leg portions of the p-type and n-type semiconductor elements are damaged and the characteristics are impaired.

Therefore, an object of the present invention is to solve the above problems and provide a thermoelectric conversion element which is excellent in mechanical strength, small in size, and excellent in space factor.

[0005]

To achieve the above object, in a thermoelectric conversion element according to the present invention, one of an n-type semiconductor element and a p-type semiconductor element is formed in a tubular shape, and the other semiconductor element is formed into one. It is characterized in that it is formed in a rod shape so as to have the same electric resistance value as the cylindrical semiconductor element, the rod-shaped semiconductor element is embedded in the cylindrical semiconductor element through an insulator layer, and a bonding electrode is provided at one end of both semiconductor elements. I am trying. The n-type and p-type semiconductor devices can be made of different alloy materials having the same electrical resistivity. In that case, the n-type and p-type semiconductor elements can be configured to have the same cross-sectional area so as to have the same electric resistance value. Alternatively, the n-type and p-type semiconductor devices can be composed of different alloy materials with different electrical resistivities. In that case, the n-type semiconductor element and the p-type semiconductor element can be configured to have the respective cross-sectional areas so as to have the same electric resistance value. The insulator layer interposed between the n-type and p-type semiconductor elements is preferably made of an alumina sprayed film, but may be made of an insulating ceramic plate instead.

[0006]

In the thermoelectric conversion element according to the present invention having the above-described structure, since the rod-shaped semiconductor element is embedded in the cylindrical semiconductor element with the insulating layer interposed therebetween, the thermoelectric conversion element has a large durability against lateral load. Will be obtained. Further, since it has the concentric structure, the outer size can be reduced and the size can be reduced.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIG. FIG. 1 shows an embodiment of the present invention.
Is a cylindrical n-type semiconductor element, and 2 is a round bar-shaped p-type semiconductor element. Both semiconductor elements 1 and 2 are configured to have the same electrical resistance value in order to improve the characteristics of the thermoelectric conversion element, and each can be formed, for example, by punching a semiconductor material. In order to make both the semiconductor elements 1 and 2 have the same electric resistance value, the cross-sectional area of the semiconductor elements may be changed according to the difference in the electric resistivity of the material forming the respective semiconductor elements 1 and 2. Alternatively, the electrical resistivity can be controlled by adjusting the amount of the additive element. The round bar-shaped p-type semiconductor element 2 has a cylindrical n-type.
The semiconductor layer is inserted into the semiconductor element 1 in a nested manner, and an insulator layer 3 made of an alumina irradiation film is formed between the semiconductor elements 1 and 2 to be integrated. A pn junction electrode 4 is formed on one end of the assembly thus integrated by brazing or diffusion. The thermoelectric conversion element thus configured is enclosed in a glass tube or a ceramic tube (not shown) in an environment where it may be corroded, oxidized, or reduced in use. Can be used.

Specific examples will be described below. An example in which the materials constituting the semiconductor elements 1 and 2 have similar electrical resistivity; the cylindrical n-type semiconductor element 1 has an electrical resistivity of 1 mΩcm, an inner diameter of 5.1 mm, an outer diameter of 7.1 mm and a length. Ten
mm P-doped SiGe alloy, while the round bar-shaped p-type semiconductor element 2 is made of B-doped SiGe alloy having an electrical resistivity of 1 mΩcm, a diameter of 5 mm, and a length of 10 mm. The electric resistance of the device was 5.1 × 10 ^-3 Ω. Also p
The n-junction electrode 4 was composed of a MoSi eutectic alloy having a diameter of 7.1 mm and a thickness of 1.0 mm.

An example in which the materials constituting the semiconductor elements 1 and 2 have different electrical resistivities; the cylindrical n-type semiconductor element 1 is
It has an electrical resistivity of 3 mΩcm, an inner diameter of 5.1 mm, an outer diameter of 10.1 mm,
It is composed of a P-doped SiGe alloy with a length of 10 mm, while a p-shaped rod
Type semiconductor element 2 has an electrical resistivity of 1 mΩcm and a diameter of 5
mm, and the length was 10 mm, it was composed of a B-doped SiGe alloy, and in this case as well, the electric resistance value of each semiconductor element was 5.1 × 10 ⁻³ Ω. The pn junction electrode 4 has a diameter of 10.1 as in the case of
It was composed of a MoSi eutectic alloy with a thickness of 1.0 mm and a thickness of 1.0 mm.

By the way, in the illustrated embodiment, both semiconductor elements having a circular cross section are used to form a columnar shape.
Each semiconductor element may be formed in a polygonal cross section to have a polygonal columnar structure. In the illustrated embodiment, n
Type semiconductor element is formed in a cylindrical shape, and a rod-shaped p-type semiconductor element is inserted therein. Instead, the p-type semiconductor element is formed in a cylindrical shape or a polygonal cylinder shape, and a cross section is formed therein. It is also possible to insert a circular or polygonal rod-shaped n-type semiconductor element. Further, the insulator layer interposed between the n-type and p-type semiconductor elements is made of an alumina sprayed film in the illustrated embodiment, but is instead made of an insulating ceramic or glass plate or cylinder. It is also possible.

[0011]

As described above, in the thermoelectric conversion element according to the present invention, the other semiconductor element is embedded inside one of the n-type and p-type semiconductor elements via the insulating layer. Compared with the conventional U-shaped structure, it is stronger against load weight and easier to handle, and it can be constructed in a small size, which has a superior space factor and greatly improves usability. Like

[Brief description of drawings]

FIG. 1 is a schematic exploded perspective view showing a thermoelectric conversion element according to an embodiment of the present invention.

FIG. 2 is a schematic front view showing an example of a conventional thermoelectric conversion element.

FIG. 3 is a schematic front view showing another conventional thermoelectric conversion element.

[Explanation of symbols]

 1: Cylindrical n-type semiconductor element 2: Round bar-shaped p-type semiconductor element 3: Insulator layer 4: pn junction electrode

Claims (6)

[Claims] 1. One of an n-type semiconductor element and a p-type semiconductor element is formed in a cylindrical shape, and the other semiconductor element is formed in a rod shape so as to have the same electric resistance value as that of the one cylindrical semiconductor element. A thermoelectric conversion element, characterized in that a rod-shaped semiconductor element is embedded in the element via an insulating layer, and a bonding electrode is provided at one end of both semiconductor elements. 2. The thermoelectric conversion element according to claim 1, wherein the n-type and p-type semiconductor elements are made of different alloy materials having the same electric resistivity. 3. The thermoelectric conversion element according to claim 2, wherein the n-type and p-type semiconductor elements have the same cross-sectional area. 4. The thermoelectric conversion element according to claim 1, wherein the n-type and p-type semiconductor elements are made of different alloy materials having different electric resistivities. 5. The thermoelectric conversion element according to claim 1, wherein the insulator layer interposed between the n-type and p-type semiconductor elements comprises an alumina sprayed film. 6. The thermoelectric conversion element according to claim 1, wherein the insulator layer interposed between the n-type and p-type semiconductor elements is made of an insulating ceramic plate.