JPH02271683A - Thermoelectric element and manufacture thereof - Google Patents

Abstract

PURPOSE:To improve adhesive properties of a semiconductor material for causing Peltier effect with metal, to enhance performance and to facilitate manufacture thereof by forming a metal film on the surface of the semiconductor, and adhering the metal film with electrode metal by solder or conductive adhering material. CONSTITUTION:Metal films 9a, 9b are formed on the surfaces of semiconductors 8p, 8n for causing Peltier effect, and electrode metals 10a, 10b are adhered to the films 9a, 9b by solder or conductive adhering material. Thus, since the adherence is rigid and the metals are adhered, the adhering surface does not repel the solder. Accordingly, air bubbles are scarcely introduced, both thermal resistance and electric resistance are reduced to improve the efficiency of a thermoelectric element. Thus, the adherence is rigid, and the efficiency of the element can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a thermoelectric element used in an air conditioner that electrically cools or heats air by utilizing the Peltier effect, or a power generating device that generates electricity by using a temperature difference due to the Seebeck effect. and improvement of its manufacturing method.

2. Description of the Related Art Conventionally, a thermoelectric element that converts heat into electricity or electricity into heat is used to convert a P-type semiconductor 4 or an N-type semiconductor into a P-type semiconductor 4 or an N-type semiconductor using a metal plate 1 and a metal plate 2, as shown in a conventional example in FIG. 3, and generates electricity by the temperature difference between metals on both sides, or cools or generates heat by applying voltage and passing current.

Problems to be Solved by the Invention In such a conventional thermoelectric device, as shown in FIG. It is attached and held. Bonding between the semiconductor 3.4 and the metal plate 1.2 is generally performed using solder, but there is a problem that the solder and the semiconductor 3.4 are not compatible with each other and easily come off, resulting in low reliability. Ta. Also, the heating side or cooling side is the substrate 7.
However, since the substrate 7 becomes a thermal resistance and increases the temperature difference between the heat generating side and the cooling side of the thermoelectric element, it significantly deteriorates the performance of the thermoelectric element. In addition, in such a configuration, in order to increase the heat transfer area, it is necessary to newly add the substrate 7 side,
Alternatively, it is necessary to bond a heat dissipation fin to the opposite side, but since the bonding surface is limited, the fin efficiency not only deteriorates, but also there is a problem that the efficiency decreases due to contact resistance, and it is also bulky. There were also challenges.

In view of these problems of the prior art, the present invention improves the bonding between the semiconductor material and metal that causes the Peltier effect, and provides a configuration that allows a large heat transfer area.
The object of the present invention is to provide a thermoelectric element that has high performance and is easy to manufacture, and a method for manufacturing the same.

Means for Solving the Problems The present invention is intended to solve the above problems, and includes the following means.

(1) A metal film is formed on the surface of a semiconductor that causes the Peltier effect, and as a result, the semiconductor and metal can be directly bonded. A method for manufacturing a thermoelectric element, in which the electrode metal and the metal film are then bonded using solder or a conductive bonding material.

(2) A thermoelectric element made by making the metal rod-shaped or wire-shaped and sandwiching and bonding a semiconductor that produces a Peltier effect.

(3) P-type semiconductors and N-type semiconductors that produce a Peltier effect are alternately sandwiched and bonded using metal rods or metal wires, and the metal rods or metal wires are bent into a U-shape.
A thermoelectric element configured so that semiconductors are arranged almost in a line. Note that it is preferable that the semiconductor be placed inside the heat insulating wall. 4) After forming a film of a semiconductor that produces a Peltier effect on the end face of a metal rod, metal wire, or metal plate, and then forming a film of metal, Or, a method for manufacturing a thermoelectric element by joining metal wires or metal plates with solder or a conductive bonding material.

Effects The effects obtained by the above means are as follows.

(1) The semiconductor and thin film metal are directly bonded, and the metal and electrode metal are bonded by a method such as soldering, so the bond is strong. In addition, since it is a metal-to-metal bond, the bonding surface does not repel solder, which allows air bubbles to enter.Both thermal resistance and electrical resistance are lowered, improving the efficiency of the thermoelectric element.

(2) Since the semiconductor is sandwiched between metal rods or wires without using a substrate, the heat transfer area is wide and heat radiation or heat absorption efficiency is high.

(3) Since the semiconductor section is provided within the heat insulating wall, there is little heat leakage from the high temperature side to the low temperature side.

(4) Since the easily deformable metal part is bent into a U-shape to form a wave shape, manufacturing is easy and the amount of heat dissipation can be easily adjusted.

(5) Since the metal bonded on both sides of the semiconductor is rod-shaped, linear, or thin plate-shaped, the development of a boundary layer is small and a heat dissipation fin with high heat transfer coefficient can be obtained.

(6) After forming a film of a semiconductor that produces a Peltier effect on the end face of a metal rod, metal wire, or metal plate, and then forming a metal film, solder or conductive joining the metal rod, metal wire, or metal plate. Since a manufacturing method is used in which materials are joined together, the process is simple and it is easy to create. Furthermore, since a thin film is used, the amount of rare metal materials used is small.

Examples Examples according to the present invention will be described below with reference to the drawings. 1st
The figure shows a schematic configuration of a linear thermoelectric element in an embodiment of the present invention.

In FIG. 1, a thin copper film 9as9b is formed on each end surface of a P-type semiconductor 8P and an N-type semiconductor 8n using a process such as vacuum evaporation, plating, or thermal spraying. Also,
This copper thin film θas9b is joined to copper wires 10a and 10b by solder. The copper wires 10a and 10b have a U-shaped structure in which their substantially central portions are bent, and the semiconductor 8P18n is configured to be located substantially in the center of the thermoelectric element. By applying a voltage to both ends of this linear thermoelectric element and passing a current, a heat generating part and a cooling part are generated at both ends of each of the P-type and N-type semiconductors 8P and 8n, and the heat is
The heat exchanges with the outside air through the conducting wire 10a110b.

In this embodiment, since P-type and N-type semiconductors 8P18n are arranged alternately, each copper wire 10a side or 10b
All sides are either hot or cold.

With such an element manufacturing method and configuration, the copper wire 10
The a110b and the semiconductor 8Pt8n are not only strongly bonded and durable (but also the solder on the bonding surface is well wetted,
Since there are no bonding defects due to bubbles, etc., contact resistance is low, thermal resistance is also reduced, and thermoelectric performance is improved. Also, copper wire 1
Since the length of 0a110b can be adjusted appropriately according to the load, appropriate heat radiation or heat absorption is possible.

It is easy to attach fins or the like to the copper wires 10a and 10b depending on the case, so that they can respond very flexibly to thermal loads.

FIG. 2 shows a thermoelectric element in another embodiment of the present invention,
It uses a thin film semiconductor. Unlike the embodiment shown in FIG. 1, this embodiment has a semiconductor thin film 1 on the end face of the copper plate 11a.
2 is formed into a film using a process such as vapor deposition, and a copper thin film 13 is formed on top of the film.

Thereafter, the copper thin film 13 and the copper plate 11b are soldered or soldered.

By bonding them together using a conductive bonding material, a thermoelectric element is constructed. In this embodiment as well, when a voltage is applied to the copper plate 11a11Lb and a current is caused to flow, a heat absorbing part and a heat generating part are generated at the interface between the semiconductor thin film 12 and the copper thin film 13, and at the interface with the semiconductor thin film 12, which are transmitted through the copper plate 11a111b and connected to the surroundings. Perform heat exchange. By using the thin film semiconductor 12 in this manner, the amount of material used can be reduced and the weight can be reduced compared to the case of bulk.

Although a single element is shown in this embodiment, the semiconductor thin film 12 may be formed on the side end surfaces of the copper plates 11a and 11b as shown in the embodiment of FIG. Needless to say, it is also possible to have a structure in which N-type semiconductors are alternately connected in series and the copper plates between them are bent.

FIG. 3 shows an example of the use of a cooling/heating machine using the thermoelectric element of this embodiment, and the semiconductor 8a of the thermoelectric element shown in FIG.
A heat insulating wall 15 is provided to cover s8b.

Copper wires 10a and 10b are installed on both sides of this heat insulating wall 15.
protrudes and is configured to exchange heat with the flowing air 17a, 17b. The thickness of the heat insulating wall 15 needs to be changed depending on the temperature difference between the air 17a and 117b.
Copper wire 10a11ob so that 0b can sufficiently exchange heat
Change the length appropriately. By passing a current through this linear thermoelectric element 14, one of the air 17a, 17b is heated and the other is cooled. In other words, it can be used for heat pump air conditioners and refrigerators.

In addition, depending on the amount of heat dissipation on the cooling side and the heat generation side, the copper wire 10a,
By changing the length of 10b, the optimum heat dissipation condition can be achieved from the viewpoint of economy and efficiency, resulting in a cooling and heating machine with good performance and low cost. Further, since it is easy to connect a plurality of linear thermoelectric elements 14 in parallel to increase the output, there is a high degree of freedom in dealing with various loads. Also steel wire 10a
, 10b made of thin wires, the linear thermoelectric element 14 becomes very flexible, so that it is less likely to be damaged.

Of course, the thermoelectric cord having this configuration according to the present invention can also be used when converting heat from a heat source into electricity by the Seebeck effect, and it goes without saying that similar effects will be produced in that case as well.

Effect of the invention The present invention has the following effects.

(1) Since a bonding material such as solder is always used to bond metal surfaces, the bond is strong, has low thermal resistance and electrical resistance, and has high element efficiency. (2) It is extremely flexible, lightweight, and has low material costs. (3) Since the heat transfer area can be widened, the temperature difference with the external load is reduced, and heat radiation efficiency is improved. (4) Since the high-temperature side and the low-temperature side are separated by a heat insulating wall and the thermoelectric element is installed within the wall, the amount of heat leaked is reduced and the overall cooling or heating performance is improved. (5
) A thin film of semiconductor and metal is formed on a metal electrode,
Since a manufacturing method is used in which the thermoelectric element is bonded to a metal electrode by soldering or the like, it is not only easy to manufacture, but also a thermoelectric element that is strong, lightweight, and has good performance can be manufactured at low cost.

In other words, by implementing the present invention, it is extremely strong, lightweight,
Moreover, it is possible to stably produce a thermoelectric element that is highly economical and has high cooling or heating performance.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a linear thermoelectric element according to an embodiment of the present invention, FIG. 2 is a schematic diagram of a plate thermoelectric element according to another embodiment of the present invention, and FIG. A perspective view showing an example of the use of a heating/cooling machine using a linear thermoelectric element. FIG. 4 is a perspective view of a conventional thermoelectric element. 8P, 8ns 12. ,,semiconductor,10 all 0
b. 9. Copper wire, lla, llb,... Copper plate, 12... Semiconductor thin film, 13... Copper thin film, 15. ,,insulated walls. Name of agent: Patent attorney Shigetaka Awano 1 person

Claims (5)

[Claims] (1) Manufacturing a thermoelectric element in which a metal film is formed on the surface of a semiconductor that produces a Peltier effect using a vacuum film forming method or an atmospheric pressure film forming method, and the metal film and electrode metal are bonded using solder or a conductive bonding material. Method. (2) A thermoelectric element in which a semiconductor that produces the Peltier effect is sandwiched between metal rods or metal wires and bonded to them. (3) P-type semiconductors and N-type semiconductors that produce a Peltier effect are sandwiched and bonded alternately between metal rods or metal wires at intervals, so that the P-type semiconductors and N-type semiconductors are arranged almost in a line. and a thermoelectric element formed by bending the metal rod or metal wire into a U-shape. (4) The thermoelectric element according to claim 3, wherein the semiconductor that produces the Peltier effect is disposed inside the heat insulating wall. (5) After forming a film of a semiconductor that produces a Peltier effect on the end face of a metal rod, metal wire, or metal plate, and then forming a metal film, solder or conductive joining the metal rod, metal wire, or metal plate. A method for manufacturing thermoelectric elements bonded by materials.