JPH085572Y2 - Thermoelectric element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a structure of a thermoelectric element.

[Outline of device]

According to the present invention, in the structure of a thermoelectric element, a plurality of thermoelectric materials are formed by a thick film method, a plurality of glass plates and organic resins are laminated and adhered, and two of the plurality of thermoelectric materials are electrically connected by electrodes. An insulating layer is formed on an electrode, and an electric heating plate is attached to the insulating layer to easily obtain a high-performance thermoelectric element.

[Conventional technology]

In an electronic wrist watch, a semi-permanent power supply can be obtained by combining a thermoelectric element using body temperature with a large-capacity capacitor or a secondary battery.

In this case, there is a (Bi, Sb) ₂ (Te, Se) ₃ type thermoelectric material that has the best figure of merit at around room temperature. Seebeck coefficient of this material is about 200μV / k for both N type and P type. Therefore, for example, to obtain a voltage of 2V with a temperature difference of 2 ° C, 5
Thousands of elements are needed.

Moreover, in the case of a wrist watch, the usable area is limited to about 6 cm ² , so each element is, for example, 0.1 mm × 0.1 mm.
mm × 7 mm, which requires the use of thick film methods to form thousands of such minute elements.
There are examples such as Proceedings of the 61st Annual Meeting of the Institute of Electrical Engineers of Japan, 1986, etc. In this case, it is necessary to use glass or the like as the substrate for forming the thermoelectric material.

[Problems to be solved by the device]

When forming a thermoelectric material by the thick film method, (Bi, Sb) ₂ (Te, Se) ₃
In the case of thermoelectric materials, it will be sintered in a non-oxidizing atmosphere at about 500 ° C, and there is glass etc. as the substrate. In this case, the thermal conductivity will be as large as 0.01w / cm ・ k, and a temperature difference is unlikely to occur. Become.

[Means for solving the problem]

In the present invention, the thermoelectric element has a structure in which a thermoelectric material is embedded in a heat insulating member, and the heat insulating member is an inorganic substance that can withstand the sintering of the thermoelectric material such as glass or mica. As shown in the cross-sectional view of FIG. 2, the thermoelectric material 1 has a structure in which the glass 2 and the organic resin 3 surround the periphery.

At this time, the volume of a member such as an organic resin having the smallest thermal conductivity is made as large as possible.

Further, in particular, porous glass or porous organic resin is used as the heat insulating member.

[Action]

By using an inorganic substance that can withstand the sintering of thermoelectric materials as a heat insulating member for fixing thermoelectric elements, a large number of fine and fine thermoelectric materials can be easily formed by the thick film method, and heat insulation with a small thermal conductivity like organic resin is possible. Making the volume of the member as large as possible can increase the temperature difference applied to the thermoelectric element.

〔Example〕

 The details will be described below with reference to the drawings.

As shown in the sectional view of FIG. 3, the thermoelectric material 1 is formed on the glass 2 at regular intervals by the thick film method.

Next, as shown in the sectional view of FIG. 4, the thermoelectric material 1 is covered with the organic resin 3. Next, as shown in the sectional view of FIG.
Are removed by etching except the portion of the thermoelectric material 1. An organic resin having the thermoelectric material thus obtained fixed thereon is adhered and laminated, and as shown in FIG.
Also, the thermoelectric element has a structure surrounded by the organic resin 3. Further, as shown in a plan view in FIG. 6, electrodes 4 are formed between the thermoelectric materials so as to be in series.

The thermoelectric element manufactured as described above is completed by forming the insulating layer 5 on the electrode 4 and further attaching the heat transfer plate 6 as shown in the sectional view of FIG.

In this way, using (Bi, Sb) ₂ (Te, Se) ₃ based thermoelectric material,
One dimension of thermoelectric material is 0.1mm × 0.1mm × 7mm, consisting of 5600 N-type and P-type, outer shape is about 24mm × 21mm
A × 8 mm thermoelectric element was manufactured, and an electronic wrist watch having a power generation section 7 having a thermoelectric element and a display section 8 was manufactured as shown in the perspective view of FIG. When this electronic wristwatch was worn on the wrist at an ambient temperature of 24 ° C, a voltage of 1.9V was generated. This is a performance that can be sufficiently used for electronic wrist watches.

When glass is used as the heat insulating member, its thermal conductivity is
It is about 0.01w / cm ・ k, but for organic resins such as epoxy
Some of them have a volume of about 0.001 w / cm · k. Therefore, the volume of the inorganic substance forming the thermoelectric material is made as small as possible by the thick film method such as glass to reduce the volume of the organic resin having a small thermal conductivity as in this example. By increasing the temperature, the temperature difference generated in the thermoelectric element increases, and therefore the voltage generated also increases.

Further, when the inorganic substance or the organic resin is made into a porous substance, the apparent thermal conductivity becomes small, and more preferable results can be obtained.

As a porous substance, glass obtained by acid elution of phase-separated glass or hydrolysis of metal alkoxide is particularly useful, and it has a few 10Å fine porosity and sufficient mechanical strength, and was used for the thick film method. In this case, the adhesive strength with the thermoelectric material is also excellent.

As the organic resin, a porous polymer film that utilizes phase separation and gelation in a solvent can be used.

In addition, a porous body obtained by press-molding granules can be used for both the inorganic substance and the organic resin.

An example of an electronic wrist watch using the thermoelectric element manufactured as described above is shown in FIG.

It is composed of a power generation section 7 composed of a thermoelectric element and a display section 8 having therein a charging device such as an electronic circuit and a large-capacity capacitor.

[Effect of device]

As described above, according to the present invention, it is possible to easily obtain a high-performance thermoelectric element by using a structure in which the thermoelectric material is embedded in a heat insulating member made of an inorganic substance such as glass and an organic resin. is there.

[Brief description of drawings]

1 and 2 are a plan view and a cross-sectional view, respectively, of the thermoelectric element, FIGS. 3 to 5 are cross-sectional views showing the steps of forming the thermoelectric element, and FIG. 6 is an electrode formation on the thermoelectric element. FIG. 7 is a plan view showing a state, FIG. 7 is a sectional view of the thermoelectric element in a completed state, and FIG. 8 is a perspective view of an electronic wristwatch using the thermoelectric element. 1 ... Thermoelectric material 2 ... Glass 3 ... Organic resin 4 ... Electrode 5 ... Insulating layer 6 ... Heat transfer plate 7 ... Power generation section 8 ... Display section

Claims (3)

[Scope of utility model registration request] 1. One of the thermocouples is embedded in the organic material (3) with one surface of the plurality of thermoelectric materials (1) exposed and spaced apart, and the exposed surface of the thermocouple (1) is Inorganic substance (2)
Is a thermoelectric element each covered, the other of the thermocouple is a thermoelectric element different in only the type of the thermoelectric material consisting of the same configuration as above, and a plurality of them are provided, and one of the thermocouples and The other is alternately arranged at intervals, and these intervals are bonded and laminated with an organic resin (3), and electrodes are provided at both ends of the thermoelectric material (1) so that the thermocouples can be connected in series. Characteristic thermoelectric element. 2. The thermoelectric element according to claim 1, wherein the organic resin (3) is porous. 3. The thermoelectric element according to claim 1 or 2, wherein the inorganic substance (2) is glass or mica.