JPS6076179A - Thermoelectric converter - Google Patents

Abstract

PURPOSE:To enable effective heat absorption and radiation while obtaining electric insulation as well as to facilitate installation by arranging a multiplicity of semiconductor elements for thermoelectric conversion between a pair of heat absorbing and heat radiating plates, each of the elements being adhered at one end to each of the electrode foils facing to each other. CONSTITUTION:When a DC power supply is connected, a metallic plate 1 is cooled and a metallic plate 2 is heated. On the other hand, when the power supply is connected reversely, the metallic plate 1 is heated while the metallic plate 2 is cooled. Further, when a load instead of the power supply 31 is connected between terminals 27 and 28 so as to heat or cool the metallic plate 1 and to cool or heat the metallic plate 2, a predetermined power can be supplied to the load. Accordingly, in the operation of this thermoelectric converter as mentioned above, the metallic plate 1 and 2 holding semiconductor elements 25 and 26 can function more efficiently as heat absorbing or heat radiating plates than conventional holding plates of ceramic or the like, whereby heating/cooling and electricity generation can be performed efficiently.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a thermal lightning conversion device having a large number of semiconductor elements for thermoelectric conversion.

A thermal lightning conversion element formed by electrically connecting an N-type semiconductor element for thermal lightning conversion and a P-type semiconductor device in series is further electrically connected in series to obtain a desired heat absorption/heat generation effect or electric power. The thermoelectric conversion device requires a holding member 1, that is, a holding plate, to firmly hold and fix the large number of thermoelectric conversion elements. As such a holding plate, a ceramic plate made of a sintered body of alumina, for example, has conventionally been used. By the way, this holding plate itself can provide electrical insulation between the thermal lightning conversion element and other mounting members, but its thermal conductivity is 0.2 to 0.3 W/
Since the value is as low as cm/°C, it is difficult to effectively absorb and dissipate heat to obtain a specified mechanical strength.In addition, since it is relatively brittle, cracks may occur due to thermal strain. Therefore, it is difficult to use it for things that are rapidly cooled or heated, and it is not very satisfactory.

The present invention has been made in view of the above points, and its purpose is to effectively absorb and radiate heat, and at the same time, to achieve electrical insulation from other members, and to provide insulation to heat sources and heat radiation sources. It is an object of the present invention to provide a thermal lightning conversion device that can be easily installed (t-1), has sufficient mechanical strength, and does not crack due to thermal strain.

According to the present invention, the object is to provide a metal plate having high thermal conductivity and a desired mechanical strength, and to electrically insulate one side of the metal plate. An insulating film is bonded to the insulating film and has a relatively high thermal conductivity, and a large number of electrode foils are separated from each other and bonded to this insulating film. This is achieved by a thermal lightning conversion device in which each of the semiconductor elements is arranged with one end surface adhered to each of the electrode foils facing each other.

In the thermoelectric conversion device according to the present invention, since the metal plate substantially functions as a holding plate, the thermal resistance can be reduced by 1q, heat absorption,
A satisfactory heat dissipation effect can be obtained. Furthermore, since it is a metal plate, it has relatively good ductility, which prevents accidents such as cracking due to thermal strain, etc. 17 In addition, combined with the flexibility of the insulating film, it can be deformed into various shapes. As a result, it is possible to provide thermal lightning conversion devices in various shapes such as flat, prismatic, cylindrical, and spherical.

As the metal plate of the present invention, iron, preferably aluminum, copper, or an alloy thereof can be used, and when weight reduction is desired, aluminum or an alloy thereof is preferable. Further, the thickness of the metal plate can be set to various values from the viewpoint of thermal time constant and mechanical strength, and in a preferred example, the thickness is 1 g.
The size is 0.51IIl to 2ml0, and in order to improve heat absorption and heat radiation characteristics, a large number of heat absorption fins and heat radiation fins are installed integrally or separately on the surface opposite to the surface on which the insulating film is formed. Providing the fins in this manner increases the mechanical strength of the metal plate, allows implementation of a thin metal plate, and at the same time reduces the substantial thermal time constant, thereby achieving desirable characteristics.

The insulating film used in the thermoelectric conversion device of the present invention is preferably made of polyimide resin having excellent heat resistance, particularly preferably Kebuton (trade name) manufactured by DuPont. This insulating film, ie, film, is preferably formed as thin as possible from the viewpoint of thermal conductivity, and in one specific example, the thickness is about 20 μm. The thermal conductivity of the Kubuton is 0.24
The thermal conductivity is approximately xlOW/cm·°C, and when the thickness is approximately 20 μm, the purpose of the initial JIJ can be sufficiently achieved even with this level of thermal conductivity.

Note that other resins having heat resistance may also be used, and if necessary, a filler material with high thermal conductivity may be mixed into the resin to obtain high thermal conductivity in addition to heat resistance. J, Ku,
For example, alumina or the like can be used as the filler material. When adhering such an insulating film to a metal plate, it is preferable to use an adhesive made of heat-resistant Epo-4 resin. Similar to the insulating film, filler such as alumina may be mixed into this adhesive to improve heat conduction, and thereby a thermal conductivity of about 1xlOW/cm.degree. C. can be obtained. In one preferred embodiment, the thickness of the adhesive layer is approximately 40 μm.

Copper, nickel, tin, etc. can be preferably used as the electrode foil of the present invention, and the electrode foil is formed by adhering a foil or film made of these metals to an insulating film with an adhesive. In a preferred embodiment, this electrode foil is formed from a copper foil having a thickness of 100 .mu.m. For adhesion between the electrode foil and the insulating film, it is best to apply the adhesive described above in the same way.
The thickness of this adhesive layer is also about 40 μm in one specific example.

In order to separate the electrode foils from each other, a so-called printed circuit board pattern manufacturing technique can be applied. That is, for example, a copper foil is bonded to cover the entire surface of one side of the insulating film.
Thereafter, the copper foil is etched to remove unnecessary copper foil and form electrode foils separated from each other.

The semiconductor element according to the present invention is made of a crystal or sintered semiconductor, and in the case of series connection, P-type semiconductor elements and N-type semiconductor elements are arranged alternately and electrically connected to the electrode foil at one end surface. connected. Solder is used for electrical connection between electrode foil and semiconductor elements.

The present invention will be explained in more detail below using preferred specific examples shown in the drawings.

In the figure, on one side 3 and 4 of a pair of metal plates 1 and 2 made of aluminum, which face each other, are insulated with a polyimide resin film having relatively high thermal conductivity. ! 5 and 6 are glued together. The thickness 8 of the adhesive layer 7 between the metal plate 1 and the insulating film 5 is about 40 μm, and the thickness 10 of the adhesive layer 9 between the metal plate 2 and the insulating film 6 is also about the same. Alumina was incorporated as adhesive forming layers 7 and 9. Heat-resistant epoxy resin is applied. In addition, metal plates 1 and 2
In this specific example, the thicknesses 11 and 12 of the insulating films 5 and 6 are each 1 ml1, and the thicknesses 13 and 14 of the insulating films 5 and 6 are about 20 μm. A large number of electrode foils 11 and 18 separated from each other are adhered to one side 15 and 16 of each of the insulating films 5 and 6, and the thicknesses 19 and 20 of the copper electrode foils 17 and 18 are respectively 100 μm. It is. Adhesive layers 21 and 22 similar to adhesive layers 7 and 9 are interposed between electrode foils 17 and 18 and insulating films 5 and 6, respectively. Insulating film 5
and 6, electrode foils 11 and 18 are metal plates 1 and 2, respectively.
electrically isolated from In this way, one heat absorbing/heat dissipating plate 23 consisting of the metal plate 1, the insulating film 5 and the electrode foil 11
and the other heat absorbing/heat dissipating plate 24 made up of the metal plate 2, the insulating film 6, and the electrode foil 18, P-type half-semiconductor elements 25 and N-type semiconductor elements 26 for thermoelectric conversion are arranged alternately. Been J
3. The semiconductor elements 25 and 26 are soldered to the electrodes 11 and 18 facing each other at one end, and the semiconductor elements 25 and 26 arranged in alternation between the terminals 21 and 28 are electrically connected. connected in series.

In the thermal lightning converter 3o configured as described above, when the DC power source 31 is connected as shown, the metal plate 1 side is cooled and the metal plate 2 side is heated, whereas when the power source 31 is connected in the opposite direction, the metal plate The first side generates heat, and the metal plate 2 side cools. Further, by connecting a load to the terminals 21 and 28 instead of the power source 31, heating or cooling the metal plate 1 side, and cooling or heating the metal plate 2 side, a predetermined power can be supplied to the load.

Accordingly, in the operation of such a thermoelectric conversion device 30, the metal plates 1 and 2 holding the semiconductor elements 25 and 20 can function as more efficient heat absorbing plates or heat sinks than holding plates made of ceramics or the like. Therefore, heating, cooling and power generation can be performed effectively.

Next, a method of manufacturing such a thermal lightning converter 30 will be explained. First, an insulating film 41, which will become the insulating film 5 or 6, is formed on one surface of a metal plate 40 as shown in FIG. Prepare two plates 43 with copper foil 42 bonded to the entire surface of one side of the insulating film 41, and then
An etching process is applied to remove unnecessary portions of the copper foil 42 to obtain two plates 44 as shown in FIG. 4, which serve as the heat absorbing/radiating plate 23 or 24.

Incidentally, it is preferable to apply Niracal plating to the surface of the copper foil forming the stack 17 or 18 at the stage when the plate 44 is obtained, since the subsequent soldering process can be carried out without difficulty.

Next, solder is printed on the copper foil surfaces of the two plates 44 by screen printing, and the P-type and N-type semiconductor elements 25 and 26, and the remaining plate 44 is placed thereon, and while pressing both plates 44 toward each other, the semiconductor elements 25 and 26 are bonded to the copper foil by heating to the melting temperature of the solder. Thereafter, the thermoelectric conversion device 30 can be obtained by cooling.

As described above, according to the present invention, since a metal plate is used as the holding member, it can efficiently absorb and dissipate heat, and can be easily attached to a heat absorption source and a heat dissipation source. In addition, it is easier to deform than ceramics, so devices of various shapes can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a preferred example of one piece according to the present invention;
The figure is a partially enlarged explanatory diagram of the specific example shown in FIG. 1, and FIGS. 3 to 5 are explanatory diagrams of a method of manufacturing the specific example device shown in FIG. 1.2... Metal plate 5.6... Insulating film 17, 18.
...Electrode foil 25.26...Semiconductor device Fig. 2 Fig. 3 Fig. 4

Claims (1)

[Scope of Claims] (1) A metal plate having high thermal conductivity and desired mechanical strength, and one side of this metal plate to electrically insulate the other side of the metal plate. A large number of thermal lightning conversions occur between a pair of heat absorbing and heat dissipating plates, each consisting of an insulating film that is bonded and has a relatively high thermal conductivity, and a large number of electrode foils that are separated from each other and bonded to this insulating film. 1. A thermoelectric conversion device in which each of the semiconductor elements for use is bonded at one end surface to each of the electrode foils that are arranged in pairs rK1i to each other. (2.) The thermal lightning conversion device according to claim 1, wherein the metal plate is made of aluminum. (3) The thermal lightning conversion device according to claim 1, wherein the metal plate is made of iron. (4) The thermoelectric conversion device according to claim 1, wherein the metal plate is made of copper. (5) The thermal lightning conversion device according to any one of claims 1 to 4, wherein the insulating film is made of polyimide resin. (6) The thermal lightning conversion device according to any one of claims 1 to 5, wherein the metal plate and the insulating film are bonded together with an adhesive made of heat-resistant 1-poxy resin. (7) Claims m I that the insulating film and electrode foil are bonded by an adhesive made of heat-resistant epoxy resin.
6. The thermal lightning conversion device according to any one of items Jn to 6.