JPH06188464A - Thin film thermoelectric element and manufacture thereof - Google Patents

Abstract

PURPOSE:To prevent the transfer of heat from a high temperature side to a low temperature side inside an insulating board and protect element efficiency from being degraded by dividing the insulating board to which a thin film thermoelectric material adheres into several portions, providing a span alternately. CONSTITUTION:A thin film thermoelectric material 4 is continuously installed in such a manner that it may span insulating boards 2 and 3 which are separated without contact. Metal electrodes 5 and 6 are installed to the ends of the insulating boards 2 and 3 which are separated from each other while they are placed in contact with the thin film thermoelectric material 4. Peltier effect absorbs and generates heat on an interface in contact with the thin film thermoelectric material 4, thereby producing differential temperatures on both ends of the thin film thermoelectric material 4. Since the insulating boards 1 and 2 are separated from each other in this case, this construction makes it possible to prevent heat loss resultant from the transfer of heat from a high temperature side to a low temperature side passing through the boards and obtain a compact and widely applicable thin film thermoelectric element without causing a drop in element efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoelectric element for converting heat and electricity to each other, and more particularly to a thin film thermoelectric element using a thin film material and a method for manufacturing the same.

[0002]

2. Description of the Related Art Thermoelectric materials are materials in which a voltage is generated when a temperature difference is applied to both ends and a temperature difference is generated when electricity is applied to the opposite ends. Was used to. In this case, the thermoelectric material used is a rectangular parallelepiped or cylindrical element having a side of several mm, which is called a bulk material, and a plurality of these elements are used in a standing state.

However, in recent years, attempts to form the thermoelectric material into a thin film have been made for two reasons. One is the recent development of microelectronics.
Technology such as fine processing, fine area control, thin film processing has advanced,
In thermoelectric materials as well, there is an increasing need for thin film shapes, and the number of application fields is increasing. Second, the bulk material is manufactured by a method such as melting and sintering, and the material performance is improved by adding impurities, but the current performance is not yet suitable for wide-range practical use.

Therefore, it is necessary to find a characteristic different from the conventional one by changing the manufacturing method and devising the shape, and one of them is an attempt to manufacture a thermoelectric element with a thin film material. Has been done.

In a thermoelectric element made of a thin film material, two directions can be considered as the temperature difference or the direction of energization. That is, the film surface direction and the film thickness direction. In the case of the thickness direction, it is considered that the bulk material is basically reduced in size,
In that case, a temperature difference is made in a very short distance, and heat loss is likely to occur. Also, when considering the manufacturing process, it is considered difficult to satisfactorily establish thermal contact between the front and back surfaces of the film so as to provide a heat transfer medium. Therefore, a practical method is to make the film surface direction the temperature difference or the energization direction.

An example for considering the temperature difference when current is applied in the film surface direction will be described with reference to FIG.

In the thin film thermoelectric element 11 shown in FIG.
On the surface of the insulating substrate 12, metal electrodes 13 and 14 are installed, and a thin film thermoelectric material 15 is attached. Metal electrode 1
By passing an electric current between 3 and 14, heat absorption and heat generation occur at the interface between the metal electrode 13 and the thin film thermoelectric material 15 and at the interface between the metal electrode 14 and the thin film thermoelectric material 15 due to the Peltier effect. As a result, a temperature difference corresponding to that occurs at both ends of the thin film thermoelectric material 15. And P-type and N
By arranging a large number of such elements in parallel by using a thin film thermoelectric material of the type semiconductor, it becomes possible to expand this temperature difference and use it for cooling or the like.

[0008]

However, considering the heat balance in the case of such a configuration, in addition to the heat transfer inside the thermoelectric material which usually causes heat loss even in the bulk material, a high temperature is passed through the inside of the substrate. It can be seen that heat flows from the side to the low temperature side. In other words, in contrast to the bulk material that exists alone, there is a substrate that must adhere to the thin film material, and that substrate contributes to heat loss. By comparison,
There is a problem that the element efficiency is inferior when the thin film material is used.

In view of the above-mentioned conventional problems, it is an object of the present invention to provide a thin film thermoelectric element which can be used without lowering the efficiency even when a thin film thermoelectric material is used, and a method for manufacturing the same.

[0010]

A thin film thermoelectric element according to the first invention of the present application comprises a plurality of plate-like or thin film-like insulating substrates divided at intervals, and an insulating substrate on the surface of the insulating substrate. It is characterized by comprising a thin film thermoelectric material which is continuously provided by bridging an interval between the thin film thermoelectric material and metal parts which are respectively joined to both ends of the thin film thermoelectric material.

In the method for manufacturing a thin film thermoelectric element of the second invention of the present application, the thin film thermoelectric material is adhered and the metal part is formed on the surface of the insulating substrate, and the thin film thermoelectric material is stored on the surface of the insulating substrate. It is characterized in that the insulating substrate is divided by removing the portions to provide an interval.

Preferably, the removed portion of the insulating substrate is made of a soluble organic substance.

[0013]

According to the thin-film thermoelectric element of the present invention, since the insulating substrates to which the thin-film thermoelectric material is adhered are divided into a plurality of portions with a space therebetween, the inside of the insulating substrate is heated from the high temperature side to the low temperature side. Can be prevented from being transmitted, and a decrease in element efficiency can be prevented.

Further, by depositing a thin film thermoelectric material on an insulating substrate and then removing a part of this insulating substrate, particularly by making the removed portion of a soluble organic substance and easily removing it, the thin film thermoelectric material can be easily removed. It is possible to easily manufacture the divided portion of the insulating substrate bridged by the material.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A thin film thermoelectric element according to an embodiment of the present invention will be described below with reference to FIGS.

In FIG. 1, reference numeral 1 is a thin film thermoelectric element.
Reference numerals 2 and 3 denote insulating substrates which are separated without making contact with each other, and a thin film thermoelectric material 4 is attached to the surface thereof. The thin film thermoelectric material 4 is continuously provided by bridging the gap between the separated insulating substrates 2 and 3. Insulating substrate 2,
Metal electrodes 5 and 6 are installed at the ends of the 3 apart from each other,
It is in contact with both ends of the thin film thermoelectric material 4.

In such a structure, the metal electrodes 5, 6
By passing an electric current between them, heat is absorbed by the Peltier effect at the interface between the metal electrodes 5 and 6 and the thin film thermoelectric material 4.
Heat is generated, and a temperature difference occurs at both ends of the thin film thermoelectric material 4.

In this case, in the substrate in which the insulating substrates 2 and 3 are integrated, heat is transferred from the high temperature side to the low temperature side through the inside of the substrate, resulting in heat loss. In this case, since the insulating substrates 1 and 2 are separated, such loss does not occur. As a result, there is no loss of efficiency compared to bulk materials.

Further, such a thin film thermoelectric element 1 is compact, and is expected to have a wide versatility by combining with the microelectronics technology.

Next, a method of manufacturing the thin film thermoelectric element 1 will be described with reference to FIG. First, the insulating substrates 2 and 3 are arranged at intervals and integrated with the soluble organic material 7 interposed therebetween to form the substrate 8. Then, the metal electrodes 5 and 6 are installed on both ends of the substrate 8. Next, the thin film thermoelectric material 4 is attached to the surfaces of the insulating substrates 2 and 3 and the soluble organic material 7 so as to be in contact with the metal electrodes 5 and 6. Finally, the soluble organic material 7 of the substrate 8 is dissolved and removed by an organic solvent (not shown).

In this case, the soluble organic material 7 and the organic solvent (not shown) must be those that do not affect the properties of the thin film thermoelectric material 4. Further, in order to secure the film thickness of the thin film thermoelectric material 4 to some extent from the viewpoint of the strength of the thin film thermoelectric element 1, the thin film thermoelectric material 4 may be printed, coated, etc.
There is a method of forming to a thickness of 0 μm.

By using the above-described manufacturing method, the surfaces of the plurality of insulating substrates 2 and 3 divided at intervals and the intervals between the insulating substrates 2 and 3 are bridged and continuously provided. It is possible to manufacture the thin film thermoelectric element 1 having the thin film thermoelectric material 4 thus obtained.

After depositing the thin film thermoelectric material 4 on the surface of the insulating substrate, the combustible material provided in the divided portions is completely burned and removed by heat treatment, or a part of the integrated insulating substrate is removed. The insulating substrate may be divided at intervals by a method such as removal by mechanical processing. Even if these methods are used, it is necessary to take care so as not to affect the properties of the thin film thermoelectric material 4.

[0024]

As described above, according to the present invention, since the insulating substrates to which the thin film thermoelectric material is adhered are divided into a plurality of spaces at intervals, the inside of the insulating substrate changes from the high temperature side to the low temperature side. It is possible to prevent the transfer of heat, and to obtain a thin film thermoelectric element that is compact and has a wide range of applications, without causing a decrease in element efficiency.

Further, by depositing the thin film thermoelectric material on the insulating substrate and then removing a part of the insulating substrate, in particular, the removal portion is made of a soluble organic substance and easily removed. It is possible to easily form the divided portion of the insulating substrate bridged by the material and manufacture the thin film thermoelectric element at low cost.

[Brief description of drawings]

1A and 1B show a thin film thermoelectric element according to an embodiment of the present invention, wherein FIG. 1A is a plan view and FIG. 1B is a front view.

FIG. 2 is an explanatory diagram of a manufacturing process of the thin film thermoelectric element of the example.

3A and 3B show a conventional thin film thermoelectric element, in which FIG. 3A is a plan view and FIG. 3B is a front view.

[Explanation of symbols]

 1 Thin Film Thermoelectric Element 2 Insulating Substrate 3 Insulating Substrate 4 Thin Film Thermoelectric Material 5 Metal Electrode 6 Metal Electrode 7 Soluble Organic Material

Claims (3)

[Claims] 1. A plurality of plate-shaped or thin-film insulating substrates divided at intervals, and a thin-film thermoelectric material continuously provided on the surface of the insulating substrate by bridging the intervals between the insulating substrates. And a metal part bonded to both ends of the thin film thermoelectric material, respectively. 2. A thin film thermoelectric material is adhered and a metal part is formed on the surface of the insulating substrate, and a part of the insulating substrate is removed in a state where the thin film thermoelectric material is preserved to provide the insulating substrate with a space. A method for manufacturing a thin-film thermoelectric element, characterized in that the thin film thermoelectric element is divided. 3. The method for producing a thin film thermoelectric element according to claim 2, wherein the removed portion of the insulating substrate is made of a soluble organic substance.