JP2002111081A - Peltier module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a Peltier module in which the heat absorbing face and the heat radiating face of a thermoelectric element part are prevented from being connected thermally through a metal having a high thermal conductivity covering a resin film in order to eliminate a problem of cooling performance being deteriorated due to leak of heat through the heat absorbing face and the heat radiating face. SOLUTION: A spacer 11 having thermal insulation properties is disposed around a thermoelectric element 5, and a resin film 9 on the heat absorbing face side is bonded to a resin film 9 on the heat radiating face side through the space 11, thus forming a sealing bag 10. Inner pressure of the sealing bag 10 is reduced without touching the resin film 9 on the heat absorbing face side and the resin film 9 on the heat radiating face side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a P-type thermoelectric element, an N-type thermoelectric element, and a pair of electrode layers provided with a plurality of bonding electrodes, which are used in a cooling device or the like. The present invention relates to a Peltier module having a thermoelectric element portion in which layers form a heat absorption surface and a heat radiation surface, respectively.

[0002]

2. Description of the Related Art In a Peltier module used in a cooling device or the like, when moisture enters the inside of the Peltier module, dew condensation occurs on a bonding electrode on the heat absorbing surface side, and this moisture promotes migration of electrode metal due to energization. ,
Eventually, the bonding electrode may be corroded and eventually cause a failure of the cooling device or the like. Therefore, in order to ensure the reliability of the Peltier module, it is important to prevent moisture from entering the inside of the Peltier module. Conventionally, various studies have been made on measures for preventing moisture from entering the inside of the module. For example, Japanese Patent Application Laid-Open No. 6-294562 discloses a Peltier device in which a P-type thermoelectric element, an N-type thermoelectric element, and a thermoelectric element section having a bonding electrode are wrapped in a sealing bag made of a moisture-impermeable thin film material. Module is listed.
Then, the inside of the sealing bag is depressurized (a so-called vacuum state).
Further, it is effective to use a composite film of a metal film such as aluminum and an organic film as a moisture-impermeable thin film material to prevent moisture from remaining or entering the inside of the Peltier module. It is described.

[0003]

However, the thermoelectric element is wrapped in a sealing bag made of a composite film of a metal film and an organic film, and the inside of the sealing bag is evacuated to a reduced pressure. In the module, the heat absorbing surface and the heat radiating surface of the thermoelectric element portion are thermally connected by a metal film having high thermal conductivity, causing heat leakage, and as a result, a problem that the cooling performance of the Peltier module is reduced. There was a case. And, even when metal films having high thermal conductivity are connected to each other via an organic film, the thickness of the organic film is generally thin, so that the heat absorbing surface and the heat radiating surface of the thermoelectric element portion can be separated. However, the phenomenon of being thermally connected by a metal film having high thermal conductivity also occurred.

The present invention has been made to solve the above problems, and has as its object to provide a P-type heat transfer element,
A Peltier module that wraps the N-type thermoelectric element and the thermoelectric element portion including the bonding electrode in a sealing bag made of a resin film coated on at least one surface with a metal, and pressurizes the inside of the sealing bag. The heat absorbing surface and the heat radiating surface of the thermoelectric element are prevented from being thermally connected by the metal having high thermal conductivity covering the resin film, and the heat between the heat absorbing surface and the heat radiating surface is prevented. An object of the present invention is to provide a Peltier module that prevents a problem that a cooling performance is reduced by a leak.

[0005]

According to a first aspect of the present invention, there is provided a Peltier module in which a P-type and an N-type thermoelectric element are sandwiched between a pair of electrode layers having a plurality of bonding electrodes.
Thermoelectric element part, in which a thermoelectric element and an N-type thermoelectric element are connected in series via a bonding electrode of the electrode layer, so that the electrode layers facing each other form a heat absorbing surface and a heat radiating surface, respectively. In a Peltier module in which at least one surface is wrapped in a sealing bag formed of a resin film coated with a metal and the inside of the sealing bag is in a reduced pressure state, a spacer having a heat insulating property around a thermoelectric element portion is provided. The resin film on the heat-absorbing surface side and the resin film on the heat-radiating surface side are joined via the spacer to form the sealing bag, and the resin film on the heat-absorbing surface side and the resin on the heat-radiating surface side are formed. A Peltier module characterized in that the inside of the sealing bag is kept under reduced pressure without direct contact with the film.

In the Peltier module according to the first aspect of the present invention, since the resin film on the heat absorbing surface side and the resin film on the heat dissipating surface side are joined via the spacer having thermal insulation, the heat absorption of the thermoelectric element portion is achieved. The surface and the heat radiating surface are prevented from being thermally connected by the metal with high thermal conductivity covering the resin film, and the cooling performance is reduced by heat leak between the heat absorbing surface and the heat radiating surface. A Peltier module with no problems is obtained.

According to a second aspect of the present invention, there is provided a Peltier module, wherein the resin film coated with metal is a resin film in which metal is vapor-deposited only on one side, and the sealing bag has the metal vapor-deposited surface of the resin film facing outward. The Peltier module according to claim 1, wherein the Peltier module encloses the thermoelectric element portion.

In the Peltier module according to the second aspect of the present invention, since the sealing bag surrounds the thermoelectric element portion with the metal deposition surface outside, an insulating substrate such as a ceramic substrate is provided outside the facing electrode layer. Even if it is not provided, it is possible to secure electrical insulation between the electrode plates of the same electrode layer with a resin film, and there is no so-called skeleton type Peltier module in which an insulating substrate for fixing the electrode layer is not provided. It is possible to obtain.

A peltier module according to a third aspect of the present invention is the peltier module according to the second aspect, wherein the resin film and the spacer are both formed of a heat-sealable material.

In the Peltier module according to the third aspect of the present invention, since the resin film and the spacer are both formed of a material that can be thermally welded, the sealing bag can be sealed by a thermal welding method that does not require an adhesive or the like. Thus, there is an advantage that the sealing step is simplified.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show an embodiment of the Peltier module according to the present invention, wherein FIG. 1 is a sectional view and FIG. 2 is a plan view. As shown in FIG. 1, this Peltier module has a plurality of bonding electrodes (1a or 2a).
P-type and N-type thermoelectric elements 3 and 4 are sandwiched between a pair of electrode layers 1 and 2 including And a thermoelectric element section 5 connected in series via two bonding electrodes 1a and 2a so that the facing electrode layers 1 and 2 form a heat absorbing surface and a heat radiating surface, respectively. The electrode layers 1 and 2 are respectively formed on the surfaces of ceramic substrates 6 and 7 made of alumina or the like, and the surfaces of the ceramic substrates 6 and 7 opposite to the electrode layer forming surfaces are heat absorbing surfaces of the thermoelectric element portion 5. And one of the heat radiating surfaces.

In this embodiment, a spacer 11 having a heat insulating property is provided around the thermoelectric element portion 5, and a metal-deposited resin film 9 having one surface covered with a metal 8 is provided. The thermoelectric element unit 5 and the spacer 11 are covered. Furthermore, the sealing film 10 is formed by joining the resin film 9 on the heat absorbing surface and the resin film 9 on the heat radiating surface via the spacer 11. Although the inside of the sealing bag 10 is decompressed, as shown in the plan view of FIG. 2, a lead wire 12 connecting the electrode layer 2 formed on the surface of the ceramic substrate 7 and an external power supply is sealed. Bag 1
0 to be exposed to the outside of the sealing bag 10. As the spacer 11 having thermal insulation properties, various synthetic resins, ceramic materials, and the like can be used.
A metal-deposited resin film 9 coated with metal 8
For example, a film of polyethylene, polypropylene, vinyl chloride, vinylidene chloride, or the like on which aluminum is deposited can be used. In this case, since the resin film 9 covers the thermoelectric element portion 5 and serves as a thermal resistance of heat absorption and radiation of the thermoelectric element portion 5, as long as moisture resistance can be ensured,
It is preferable to make it as thin as possible, specifically 5 to 5
Desirably, the thickness is 0 μm.

When the spacer 11 and the resin film 9 are formed of a heat-sealable material such as polyethylene, for example, the spacer 11 and the resin film 9 can be joined by a heat welding method that does not require an adhesive or the like. Therefore, there is an advantage that the sealing step is simplified.

In this embodiment, the electrode layers 1, 2
Are formed on the surfaces of the ceramic substrates 6 and 7, respectively. However, a so-called skeleton type in which an electrode layer is formed without using the ceramic substrates 6 and 7 (either one may be used). You can also. This is because the sealing bag 10 surrounds the thermoelectric element portion 5 with the metal 8 vapor deposition surface facing outward, so that the facing electrode layers 1,
This is because electrical insulation between the electrode plates of the same electrode layer can be ensured by the resin film 9 without disposing the insulating substrates such as the ceramic substrates 6 and 7 on the outside of the substrate 2.

Further, dirt and the like adhere to the heat absorbing and dissipating surfaces of the thermoelectric element portion 5 (the surfaces opposite to the electrode layer forming surfaces of the ceramic substrates 6 and 7 in the above embodiment), and irregularities (voids) are generated. In this case, the thermal resistance of heat absorption and radiation increases. In this embodiment, since the inside of the sealing bag 10 is in a decompressed state, the film 9 is in close contact with the heat absorbing and dissipating surface of the thermoelectric element portion 5 and the thermal resistance value is extremely small. In order to eliminate the influence of (1), it is effective to fill grease having good thermal conductivity between the heat absorbing and dissipating surface and the film 9. Further, as another method for reducing the thermal resistance value of the film 9 in contact with the heat absorbing and dissipating surface, using a film 9 having rubber elasticity can eliminate the influence of minute irregularities (voids) on the heat absorbing and dissipating surface. Is preferred.

[0016]

In the Peltier module according to the first aspect of the present invention, the resin film on the heat-absorbing surface side and the resin film on the heat-radiating surface side are joined via a spacer having thermal insulation. For example, the heat absorbing surface and the heat radiating surface of the thermoelectric element portion are prevented from being thermally connected by the metal having high thermal conductivity covering the resin film, and the heat leakage between the heat absorbing surface and the heat radiating surface is prevented. As a result, a Peltier module that does not cause a problem of a decrease in cooling performance is obtained.

In the Peltier module according to the second aspect of the present invention, since the sealing bag surrounds the thermoelectric element portion with the metal deposition surface on the outside, according to the present invention, the ceramic substrate is provided outside the facing electrode layer. It is possible to secure electrical insulation between the electrode plates of the same electrode layer with a resin film without disposing an insulating substrate such as a so-called skeleton, in which an insulating substrate for fixing the electrode layer is not provided. It is possible to obtain a Peltier module of the type.

In the Peltier module according to the third aspect of the present invention, since the resin film and the spacer are both formed of a material that can be thermally welded, according to the present invention, the sealing is performed by a thermal welding method that does not require an adhesive or the like. The bag can be sealed, and the sealing process is simplified.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view for explaining an embodiment of the present invention.

FIG. 2 is a plan view of the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electrode layer 1a Junction electrode 2 Electrode layer 2a Junction electrode 3 P-type thermoelectric element 4 N-type thermoelectric element 5 Thermoelectric element part 6, 7 Ceramic substrate 8 Metal 9 Resin film 10 Sealing bag 11 Spacer 12 Lead wire

Claims (3)

[Claims] 1. A P-type and N-type thermoelectric element is sandwiched between a pair of electrode layers having a plurality of bonding electrodes, and a P-type thermoelectric element and an N-type thermoelectric element are connected to each other by the electrode layer. A thermoelectric element portion connected in series via a bonding electrode so that the facing electrode layers form a heat absorbing surface and a heat radiating surface, respectively, was formed of a resin film having at least one surface coated with metal. In the Peltier module in which the inside of the sealing bag is evacuated while being wrapped in the sealing bag, a spacer having thermal insulation is arranged around the thermoelectric element portion, and a resin film on the heat absorbing surface side is provided through the spacer. And the resin film on the heat radiating surface side to form the sealing bag, and the resin film on the heat absorbing surface side and the resin film on the heat radiating surface side do not come into direct contact with each other, so that Is under reduced pressure Peltier module characterized by the following. 2. The resin film coated with metal is a resin film in which metal is vapor-deposited only on one side, and the sealing bag wraps the thermoelectric element part with the metal vapor-deposited surface of the resin film on the outside. The Peltier module according to claim 1, wherein: 3. The Peltier module according to claim 2, wherein both the resin film and the spacer are formed of a heat-sealable material.