JP2594871B2 - Thermoelectric cooler and freezer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a pair of N-type and P-type semiconductors on a heat-resistant insulating plate and using them as a thermoelectric conversion module to convert thermal energy into electrical energy (Seebeck effect) and thermal energy. The present invention relates to a device for converting energy (Peltier effect).

[0002]

2. Description of the Related Art A thermoelectric conversion module in which thermoelectric conversion element pairs are unitized based on the Seebeck effect and the Peltier effect has been developed for a long time.

In a conventional thermoelectric conversion module, as shown in FIG. 7, N-type and P-type semiconductor chips 100 and 101 are arranged so as to be adjacent to each other. In order to be connected, the low-heat-source-side element bonding metal 102 and the high-heat-side element bonding metal 103 are bonded via solder 104, respectively, and both ends of the bonded bonding metals 102 and 103 are connected by a heat-resistant insulating thin plate 105. It is assembled in a flat plate shape with the silver solder 106 interposed therebetween. The thermocouple elements of the thermoelectric conversion module are arranged electrically in series and thermally in parallel. In the figure, reference numeral 107a denotes a radiating fin constituting the radiating plate 107. In recent decades, the basic structure of such a thermoelectric conversion module has hardly changed. By the way, in the case of converting electric energy to heat energy (Peltier effect) (cascade method), it is configured to increase the cooling efficiency by stacking a plurality of such plate-type thermoelectric conversion modules in a stepwise manner. Some are.

[0004]

When a conventional thermoelectric conversion module having the above-described structure is used, in order to provide a large temperature difference between both ends of the thermocouple, as shown in FIG. A heat sink having a volume several times to several tens times larger than that of the thermoelectric conversion module having the fin 107a at one end must be attached to the low heat source side of this module. Further, even when the cascade method described above is adopted, the number of stacked thermoelectric conversion modules is physically limited.

Therefore, one technical problem of the present invention is to eliminate the defect of the thermoelectric conversion module structure used for thermoelectric cooling and to technically solve the limitation of the cooling capacity in the cascade method described above. Accordingly , it is an object of the present invention to provide a thermoelectric conversion device that is miniaturized by using a new small thermoelectric conversion module that does not use the cascade method.

Another technical object of the present invention is to provide a freezer that is downsized by using the thermoelectric cooling device.

[0007]

[0008]

According to the present invention, a thermoelectric generator is provided.
Multiple conversion modules are superimposed and electrically connected in series.
And the center of the superposed thermoelectric conversion module
In addition, a thermoelectric cooler with a tubular low heat source
Each of the thermoelectric conversion modules has a central portion of a single heat-resistant insulating plate, a ring-shaped first metal film formed around the central portion, and a pair of second half-ring-shaped second metal films. comprising a metal film, and said semi-ring-shaped N-type and P-type semiconductor thick film that is facing formed between the first and second metal films, the
The first and second metal films on a heat-resistant insulating plate;
N-type and P-type semiconductor thick films are laminated by screen printing.
Forming the second metal film as electrode terminals of the N-type and P-type semiconductor thick films, respectively, and joining the N-type semiconductor thick film and the P-type semiconductor thick film via the first metal film. thermionic cooling device is obtained, characterized by constituting the thermocouples with.

[0009]

According to the present invention, a plurality of thermoelectric conversion modules are stacked and electrically arranged in series, and a tubular low heat source is formed at the center of the stacked thermoelectric conversion modules . The tubular low heat source part of the thermoelectric cooling device
Heat exchanger connected to the end of the pipe passing through
And a cooling medium is provided between the low heat source section and the heat exchanger.
A freezer that circulates and cools the freezer compartment,
The thermoelectric conversion module is located at the center of one heat-resistant insulating plate.
And first ring-shaped first members formed around the central portion.
A metal film and a pair of semi-ring-shaped second metal films;
A semi-ring shaped counter-formed between the first and second metal films
An N-type and a P-type semiconductor thick film;
The respective electrode terminals of the N-type and P-type semiconductor thick films are
The N-type semiconductor thick film and the P-type semiconductor thick film are connected to the first
It is specially characterized that the thermocouple is constructed by joining through a metal film.
A freezer is obtained.

[0011]

[0012]

In the thermoelectric conversion module of the present invention, heat is absorbed in the first metal film at the center, which is the junction between the N-type and P-type semiconductor thick films on the heat-resistant insulating plate, and a voltage is applied. Heat is generated in the pair of second metal films serving as electrode terminals. In the present invention, the thermoelectric conversion module has a basic structure, and a plurality of the thermoelectric conversion modules are superposed and electrically connected in series. According to the specification of the thermoelectric cooling device to be manufactured, the number of thermoelectric conversion modules is superimposed and connected infinitely, and the length of the tubular cooling zone is appropriately changed to cool the thermoelectric cooling device. It is possible to cool to full capacity.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1A is a plan view showing a thermoelectric conversion module according to an embodiment of the present invention, and FIG.
It is AB sectional drawing of (a). 1 (a) and 1 (b), a thermoelectric conversion module 10 has a square heat-resistant insulating thin plate 1 having a center hole 6 provided at the center and edge holes 7a provided at four corners for forming electric contacts. And a pair of arc-shaped thick film electrodes 2 formed on the heat-resistant insulating thin plate 1.
a, 2b, a metal ring thick film 3 formed around the center hole 6 of the heat-resistant insulating thin plate 1, and an arc-shaped N-type semiconductor thick film 4
And a P-type semiconductor thick film 5 having substantially the same thickness.

The thick film electrodes 2a and 2b are made of a heat-resistant insulating thin plate 1.
Each of which has a semi-ring shape symmetrically formed with respect to the center line as cut by the center line of
Ring-shaped contacts 2c formed around the holes 7a at the four corners and projecting along the heat-resistant insulating thin plate 1 toward the corners 1a.

N-type semiconductor thick film 4 and P-type semiconductor thick film 5
Are formed between the thick-film electrodes 2a and 2b and the metal ring 3 on the heat-resistant insulating thin plate 1, respectively.
Has a half-ring shape formed symmetrically so as to be divided into two by the center line of the half circle. The N-type semiconductor thick film 4 and the P-type semiconductor thick film 5 are inscribed in the metal ring thick film 3 and are electrically connected to each other.

As described above, in the embodiment of the present invention, the shape of the semiconductor element material is made into a semi-ring-like thick film, the cross-sectional area is made small, and the surface area is made large, so that the semiconductor element material is generated from the high heat source side which is the outer periphery. The heat is easily dissipated, and the heat is easily dissipated halfway by the current. In addition, the device legs (height of the device chip) between the low heat source side, which is the inner periphery, and the outer periphery,
That is, the embodiment of the present invention corresponds to the width of the semiconductor thick film,
Can be made longer than before so that a large temperature difference can be more easily provided between the two terminals.

FIG. 2 shows a method of producing a raw material paste for forming the N-type semiconductor thick film 4 and the P-type semiconductor thick film 5 of FIG. As shown in FIG. 2, as a first step, Bi _1.8 Sb _0.2 Te _2.85 and SbI ₃ are prepared as an N-type semiconductor thick film material, and Bi is used as a P-type semiconductor thick film material.
_0.5 Sb _1.5 Te ₃ and Se were prepared (S1 stage).
In the second stage, these raw material powders were weighed in a predetermined amount such that, for example, the P-type semiconductor thick film raw material had Se of 1.75 wt% (S2 stage). As a third step, each of these raw materials was melted in a vacuum (S3 step). The ingot obtained as a fourth step was prepared by adding 5 vol% of H ₂ to Ar
Heat treatment was performed in a gas stream. In the case of an N-type semiconductor ingot, heat treatment was performed at 548 to 508 ° C. for 48 hours, and in the case of a P-type semiconductor, the heat treatment was performed at 488 to 473 ° C. for 48 hours (S
4 stages). As a fifth step, each heat-treated ingot was ground to an average powder particle size of 1-2 μm. In the next step, a raw material paste for an N-type semiconductor and a P-type semiconductor was manufactured by mixing a solvent (Step S6). As the solvent used here, an alcohol-based solvent having viscosity such as polyvinyl alcohol and polybutyl alcohol can be used. As described above, the production of the raw material paste is completed (S7 stage).

FIG. 3 shows a method of manufacturing the thermoelectric conversion module of FIG. As shown in FIG. 3, as a first step, a heat-resistant insulating thin plate 1 was prepared (S10 step).
In the second stage, as shown in FIG.
A ring-shaped electrode made of a Cu-Ti powder paste was screen-printed on the central portion and the outer peripheral portion (step S11).
As a third step, the Cu-Ti powder paste was dried (S12 step). As a fourth step, the heat-resistant insulating thin plate 1 and Cu-Ti
An electrode was formed by reacting with the powder (S13). As a fifth step, the material pastes of the N-type and P-type semiconductors are screen-printed between the electrodes so that the film thickness when dried is 2 μm.
The layers were stacked so as to have a thickness of 00 μm (S14 step). As a sixth step, the obtained thick film was dried (step S15). As a seventh step, the dried film was heated by sintering by supplying an Ar gas flow at 2 L / min. For P-type semiconductor thick film,
470 ° C. for 1 hour, 460 for N-type semiconductor thick film
C. for 1 hour (S16 stage).

Through the above manufacturing steps, the manufacture of the thermoelectric conversion module is completed (S17). The shape and dimensions of the thick-film thermoelectric conversion module can be selected according to the purpose.

FIG. 4 is an exploded sectional view schematically showing an electric connection portion of a thermoelectric cooling device using the thermoelectric conversion module of FIG. FIG. 4 shows the same member cross section as that cut along the CD in FIG. 1 except for the spring member. The thermoelectric conversion modules 10a, 10b, 10c,... 10N similar to those shown in FIG. 1 are provided with coupling electrodes 11a, 11b, 11c on alternate sides, respectively.
At both ends, module holding plates 13a each having a coupling electrode 12 at the same position as an adjacent coupling electrode 11a,
13b is arranged.

These N (where N is a natural number) thermoelectric conversion modules 10a, 10b, 10c... 10N are formed by spring members 15 disposed at both ends of a center shaft 14 via module holding plates 13a, 13b. It is urged in the direction indicated by the arrow 16 and overlaps each other. On this occasion,
For example, regarding the thermoelectric conversion module 10b, the coupling electrode 11b contacts the thick film electrode 2a of the module 10a and the coupling electrode 1b of the thermoelectric conversion module 10c.
The thick film electrode 2b contacts 1c. As described above, one end of the coupling electrode of the thermoelectric conversion module is alternately pressed against the surface of the thick film electrode of another thermoelectric conversion module, so that electrical connection is obtained in series. The thermoelectric conversion modules 10a, 10b, 10c...
And 11N are superimposed on the coupling electrodes 12a, 12b of the module holding plates 13a, 13b to obtain electrical contacts at both ends. Each coupling electrode 12
By soldering lead wires (not shown) to the outer end surfaces of a and 12b, an external lead wire such as a power supply can be easily attached.

FIG. 5A is a sectional view showing a thermoelectric cooling device having the elements shown in FIG. 4, and FIG. 5B is a side view of the thermoelectric cooling device shown in FIG. As shown in FIG.
A plurality of thermoelectric conversion modules 10 of FIG. 1 are stacked, and are pressed from both ends by spring members 15 via holding plates 13a and 13b. A tubular cooling zone is formed in the center hole 6 at the center of the laminated thermoelectric conversion module 10, and a cooling pipe 21 penetrates this portion.
Around the four side surfaces, a water-cooled radiator tube 22 having a frame-shaped internal space is disposed. The heat radiating pipe is provided with a heat radiating fluid port 23. As shown in FIG. 5B, the spring member 15 is sealed by fixing sealing plates from both ends of the heat radiating tube 22 with screws 25 as shown in FIG. 5B. With the cooling heat source portion of the thermocouple formed of the semiconductor thick film as described above centered,
A plurality of the thermoelectric conversion modules are superimposed, electrically connected in series, and a DC voltage is applied to the coupling electrodes at both ends thereof.
A tubular cooling zone along the axial direction is formed at the center.

FIG. 6A is a sectional view showing a freezer using the thermoelectric cooling device of FIG. 5, and FIG. 6B is a sectional view of the freezer of FIG. 6A. In FIG. 6A, the freezer 3
Reference numeral 0 includes first and second boxes 31 and 32 separated by a partition wall 33. The inner wall of the first box 31 is made of a heat insulating material 34a, 34b, 34c, 34d, 34e, 3
4f. These heat insulating materials 34a, 3
The interior space 41 is defined by 4b, 34c, 34d, 34e, and 34f. Here, in the present invention, the freezer refers to a device having a storage that can be cooled to a freezing temperature.

On the heat insulating material 34d of the partition wall 33, a radiator 35 having a fin 35a protruding into the internal space 41 is provided as a heat exchanger in the first box 31. The heat insulating material 34d and the partition wall are provided. 33 through the second box 32
Cooling pipes 35b and 35c protrude inside. The wall on which the heat insulating material 34a is provided on the right side of the drawing constitutes a door 45, and a handle 3 for taking in and out what is stored in the storage.
By being provided with 8, it is rotated and moved in the depth direction of the paper with the vertical end on the depth side of the paper as one axis, and is opened. A defrost tank 43 is provided at the bottom of the internal space 41.

On the other hand, the second box 32 has an opening 37 in a wall portion facing the partition wall 33, and the thermoelectric cooling device described above is accommodated in the box 32. The cooling pipes 21a and 21b at both ends of the thermoelectric cooling device 20 are connected to the protruding ends of the pipes 35b and 35c from the radiator 35 in the internal space 41 by pipe connecting pipes 36a and 36b, respectively. The second box 32 is opened from the opening 37 having substantially the same size as the outer periphery of the thermoelectric cooling device 20.
One side of the fluid port 23 side is exposed to the outside. In this example, the cooling water flows into the thermoelectric cooling device 20 from the lower fluid port 23, and the cooling water in the thermoelectric cooling device 20 flows from the upper fluid port 23.

In FIG. 6B, the three thermoelectric cooling devices fix a band 39 having a recess having a size corresponding to the width and thickness of the device 20 to the partition wall 33 with screws 40. It is attached by that. Reference numeral 44 denotes a hinge for rotatably supporting a door (see FIG. 6A) provided on the back side of the freezer.

Next, the operation of the freezer according to the embodiment of the present invention will be described. As described above, the cooling pipe 21 is penetrated and arranged in the cooling zone formed by the tubular low heat source part of the thermoelectric cooling device 20, and the cooling pipe 2
After flowing a cooling medium through the cooling medium 1 and cooling it, the cold air is conveyed into a freezing room. The cooling medium is supplied into the radiator 35 and cools the internal space 41 by absorbing heat from the internal space 41 by the fins 35.

More specifically, the cooling medium cooled in the cooling pipe of the thermoelectric cooling device increases its density and descends in the cooling pipe (see FIG. It is introduced into the radiator 35 from the pipe 35b, and the heat is absorbed by the fins 35a of the radiator 35 to reduce the density while rising, and then the thermoelectric cooling device is introduced again through the upper pipe 35c. Using the natural convection method. According to the freezer according to the embodiment of the present invention having such a configuration, the temperature of the freezer interior space 41 can be reduced to −20 ° C. without using a radiator plate as in the conventional module. In the embodiment of the present invention, as described above, a convection method using a gravitational field is employed. This method is advantageous for easily moving the cooling medium from the pipe-shaped cooling zone to the freezing compartment, but of course, in the present invention, it is also possible to circulate the cooling medium using a circulation pump.

[0030]

As described above, since the thermoelectric conversion module of the present invention has a semicircular thick-film structure, heat is also radiated from a wide thick-film surface, and the heat to the high-heat-source-side electrode end is reduced. Transmission can also be significantly reduced.

Further, the thermoelectric conversion module of the present invention
A smaller, more tubular cooling zone can be formed.

Further, the thermoelectric cooling device in which the tubular cooling zone is formed by the thermoelectric conversion module of the present invention does not require a large-scale device such as a conventional compression system, and can easily obtain a cold heat source. it can.

Further, the thermoelectric cooling device of the present invention does not require a large heat radiating plate, so that it can be made more compact, and it is easy to efficiently introduce a water-cooled radiating tube from a structural point of view, and a freezer And the cooling effect is almost the same as the cooling effect of the electronic cooling device using the conventional cascade type module.

[Brief description of the drawings]

FIG. 1 is a diagram showing a thermoelectric conversion module according to an embodiment of the present invention.

FIG. 2 is a view showing a manufacturing process of the raw material paste of FIG.

FIG. 3 is a diagram showing a manufacturing process of the thermoelectric conversion module of FIG.

FIG. 4 is an exploded perspective view schematically showing an electric connection part of a thermoelectric cooling device using the thermoelectric conversion module of FIG. 1;

FIG. 5 is a diagram showing a thermoelectric cooling device according to an embodiment of the present invention.

FIG. 6 is a view showing a freezer using the thermoelectric cooling device of FIG. 4;

FIG. 7 is a view showing a conventional thermoelectric conversion module and a heat sink.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Heat resistant insulating thin plate 2a, 2b Thick film electrode 3 Metal ring thick film 4 N-type semiconductor thick film 5 P-type semiconductor thick film 6 Center hole 7a Edge hole 10, 10a, 10b, 10c, 10N Thermoelectric conversion module 11a, 11b , 11c, 11N Coupling electrodes 12a, 12b Coupling electrodes 13a, 13b Module holding plate 20 Thermoelectric cooler 21 Cooling pipe 22 Radiator tube 24 Sealing plate 31 First box 32 Second box 33 Partition walls 34a, 34b , 34c, 34d, 34e, 34f
Insulation material 35 Radiator 35a Fin 36a, 36b Pipe connector 37 Opening 39 Band 40 Screw

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takejiro Kaneko 13-8 Asahigaoka 3-chome, Aoba-ku, Sendai, Miyagi Prefecture (56) References JP-A-2-260581 (JP, A) JP-A-4-174269 (JP) , A) JP-B-47-48037 (JP, B1) JK-49-32863 (JP, Y2)

Claims (2)

(57) [Claims] 1. A plurality of thermoelectric conversion modules are stacked.
And electrically arranged in series, and the superimposed thermoelectric
A low heat source in the form of a tube is formed at the center of the exchange module
A thermoelectric cooling device, wherein each of the thermoelectric conversion modules includes a central portion of a heat-resistant insulating plate, a ring-shaped first metal film and a semi-ring-shaped formed around the central portion, respectively. A pair of second metal films, and a semi-ring-shaped N-type and P-type semiconductor thick film formed opposite to each other between the first and second metal films . First and second metal films, and
The N-type and P-type semiconductor thick films are stacked by screen printing.
Is a layer formed, said second metal layer and each of the electrode terminals of the N-type and P-type semiconductor thick film, the N-type semiconductor thick film and the P-type semiconductor thick film through the first metal film A thermoelectric cooler characterized by being joined to form a thermocouple . 2. A plurality of thermoelectric conversion modules are stacked.
And electrically arranged in series, and the superimposed thermoelectric
A low heat source in the form of a tube is formed at the center of the exchange module
Pie passing through the tubular low heat source portion of the thermoelectric cooling device
The freezer is equipped with a heat exchanger connected to the end of the
Circulating a cooling medium between the heat source and the heat exchanger;
A freezer that cools a freezing chamber, wherein the thermoelectric conversion module includes a single heat-resistant insulating plate.
A ring-shaped ring formed around the core and the center
A first metal film and a pair of semi-ring-shaped second metal films;
A half-ring formed oppositely between the first and second metal films;
N-type and P-type semiconductor thick films, and the second metal
The film is connected to the respective electrode terminals of the N-type and P-type semiconductor thick films.
The N-type semiconductor thick film and the P-type semiconductor thick film
The thermocouple must be joined through the first metal film.
And a freezer.