JPH0846250A - Thermo-module for thermoelectric cooling - Google Patents

Abstract

PURPOSE:To prevent the positional deviation of an element in the case of manufacturing, and improve the cooling efficiency, by bonding an electrode and a thermoelectric element to a recessed part of the heat generating side insulating board in which recessed part an electrode pattern is formed. CONSTITUTION:In a thermo-module 1 for thermoelectric cooling, thermoelectric elements 5 are collectively bonding to a heat generating side insulating board 2 and a heat absorbing side insulating board 3 which face each other, via metal electrodes 4. An electrode pattern is formed on the heat generating side insulating board 2, and a recessed part 2C whose depth T is greater than the thickness of the metal electrode 4 is formed, to which part 2C the electrodes 4 and the elements 5 are bonded. Connection part material 6 is composed of material whose thermal conductivity is higher than the thermoelectric element 5, and thermaly connects the side surface of the thermoelectric element 5 with the heat generating side insulating board 2 forming the electrode pattern. Solder is used for bonding, and the heat in the element 5 can be dissipated to the heat generating side insulating board. The thermo-module for thermoelectric cooling can not only prevent the positional deviation of the element in the case of manufacturing but also improve the cooling efficiency.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoelectric cooling thermo-module for improving cooling efficiency.

[0002]

2. Description of the Prior Art Thermoelectric cooling modules are small,
It is lightweight and has a high degree of freedom in shape. Further, there is great social demand as a cooling method that does not generate noise or vibration and does not use a CFC-based refrigerant. Such thermoelectric cooling is performed with an n-type semiconductor and a p-type semiconductor.
Type semiconductors are joined via a metal electrode, and when a current is applied to the type semiconductor, heat is absorbed at the junction of the metal electrodes flowing from n-type to p-type, and at the junction of the metal electrodes flowing from p-type to n-type. Fever occurs. Also, thermoelectric cooling thermo-module
The structure is such that a plurality of thermoelectric elements are electrically connected in series to form a unit, and the upper and lower sides are sandwiched by an alumina insulating substrate that is joined and integrated with a metal electrode.

Since the thermoelectric element and the metal electrode are simply joined by soldering, the element is likely to be displaced during joining. Further, there is a drawback that the Jule heat generated in the thermoelectric element is radiated to the metal electrode and the alumina substrate only from the joint portion between the thermoelectric element and the metal electrode.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned drawbacks, the present invention is a thermoelectric cooling thermomodule which prevents displacement of elements during manufacturing and improves cooling efficiency.

[0005]

According to the present invention, an electrode and a thermoelectric element are bonded to a recess forming an electrode pattern of a heat generating side insulating substrate, and a side surface of the thermoelectric element and a heat insulating substrate are provided. It is characterized in that they are thermally connected with a material having a higher thermal conductivity than the thermoelectric element.

[0006]

According to the thermoelectric cooling thermo-module of the present invention, the heat generating side insulating substrate having the electrode pattern and having the concave portion is used, and the thermoelectric element is displaced by inserting the thermoelectric element into the concave portion. Can be prevented and soldering can be easily performed. Further, the heat inside the element is radiated by the material with high thermal conductivity connected to the side surface of the thermoelectric element, and the cooling side is cooled.
It is possible to suppress the outflow of heat.

[0007]

The present invention will be described in detail with reference to Examples and Comparative Examples.

FIG. 1 is a vertical sectional view showing an example of a thermoelectric cooling thermo-module according to the present invention. The thermoelectric cooling thermo-module 1 is mainly configured by integrally bonding the thermoelectric element 5 to the opposing heat generating side insulating substrate 2 and heat absorbing side insulating substrate 3 via the metal electrode 4. As shown in FIG. 2, an electrode pattern is formed on the heat generating side insulating substrate 2, and a recess 2C having a depth T larger than the thickness t of the metal electrode 4 is provided. The metal electrode 4 and the thermoelectric element 5 are provided in the recess 2C. By joining, the positional deviation of the thermoelectric element 5 can be prevented, and soldering can be easily performed. Although the concave portion 2C may be directly formed in the flat plate-shaped heat insulating substrate 2 with a depth T, as shown in the figure, the flat insulating substrate 2a and a plurality of electrode patterns are punched out. By joining the insulating substrate 2b thicker than the metal electrode 4 having holes, the recess 2C of the heat generating side insulating substrate 2 having the depth T larger than the thickness t of the metal electrode 4 can be easily formed. The heat absorbing side insulating substrate 3 and the metal electrode 4 are joined with an active metal brazing metal, and the metal electrode 4 joined to the heat generating side 2 and the heat absorbing side insulating substrate 3 is an n-type thermoelectric element 5a and a p-type thermoelectric element 5b. Are arranged so that they are electrically connected in series. The thermoelectric element 5 and the metal electrode 4 are joined by solder as described above, and the thermoelectric cooling thermo-module 1 of the present invention is constructed.

Next, the connecting member 6 is made of a material having a higher thermal conductivity than the thermoelectric element and thermally connects the side surface of the thermoelectric element 5 to the heat generating side insulating substrate 2 forming the electrode pattern. Since they are joined, the heat in the thermoelectric element 5 can be radiated to the heat generating side insulating substrate.

(Embodiment 1) An embodiment to which the present invention is applied will be described below. In this embodiment, the heat generation side insulation substrate and the heat absorption side insulation substrate have a cross section of 20 mm × 20 mm and a thickness of 0.
A 6 mm alumina substrate and an insulating substrate with an electrode pattern punched out were provided with 8 holes of 2 mm x 6 mm, cross section 2
Alumina substrate of 0 mm × 20 mm and thickness of 0.6 mm, copper electrode having a cross section of 2 mm × 6 mm and thickness of 0.5 mm as a metal electrode, 2 mm × 2 mm × 4 mm n-type bismuth tellurium thermoelectric element (composition: Bi _1.8 Sb _0.2 Te _2.85 Se _0.15 )
7 pieces, 2 mm x 2 mm x 4 mm p-type bismuth tellurium thermoelectric element (composition: Bi _0.5 Sb _1.5 Te _2.91 Se _0.09 ) 7
2 mm x 3 mm as a material for thermally connecting the side surface of the thermoelectric element and the alumina substrate with the electrode pattern punched out
It is an example of 7 pairs of thermoelectric cooling modules using a copper plate of x 0.5 mm.

As a manufacturing method, a flat plate-shaped insulating substrate, an insulating substrate punched with an electrode pattern and a copper electrode were joined and integrated to prepare a substrate with a heat generating side electrode. A heat absorbing side insulating substrate and a copper electrode were joined and integrated to produce a substrate with a heat absorbing side electrode.
Here, the electrode pattern of the substrate with the heat generation side and heat absorption side electrodes
The n-position was so arranged that the n-type and p-type thermoelectric elements were electrically in series. Active metal brazing (silver 7
0.5% by weight, 26.5% by weight of copper, 3.0% by weight of titanium) in the joint surface, and in an argon atmosphere at 950 ° C.
It went on condition of.

Next, the thermoelectric element and the copper electrode of the substrate with the heat generation side electrode were joined by soldering, and further the side surface of the thermoelectric element and the heat generation side insulating substrate were joined by soldering through a copper plate as a connecting member. Here, the surface of the copper plate bonded to the side surface of the thermoelectric element is 2 mm
The surface of the copper plate bonded to the substrate with the heat generation side electrode is 2 mm × 0.5 mm.

Next, the substrate with the heat absorbing side electrode and the thermoelectric element were joined by soldering. Here, the n-type and the p-type thermoelectric elements sandwiched between the substrate with electrodes on the heat absorption side and the heat generation side are electrically connected in series. Finally, the lead wire was joined with solder to obtain a thermoelectric cooling module.

(Embodiment 2) In this embodiment, 7 pairs of thermoelectric elements using a copper plate of 2 mm × 2 mm × 0.5 mm as a material for thermally connecting the side surface of the thermoelectric element and the substrate with the heat generation side electrode are used. It is an example of a cooling module. The same as Example 1 except for the shape of a copper plate that thermally connects the side surface of the thermoelectric element and the substrate with the heat generation side electrode.

(Embodiment 3) In this embodiment, 7 pairs of thermoelectric elements using a copper plate of 2 mm × 1 mm × 0.5 mm as a material for thermally connecting the side surface of the thermoelectric element and the substrate with the heating side electrode are used. It is an example of a cooling module. The same as Example 1 except for the shape of a copper plate that thermally connects the side surface of the thermoelectric element and the substrate with the heat generation side electrode.

(Comparative Example) This comparative example is a conventional thermo-module, in which a heat-insulating substrate having an electrode pattern formed thereon is thermally connected to a side surface of a thermoelectric element and a substrate having a heat-generating electrode. It is a thermoelectric cooling thermocouple module of 7 pairs without using the material. A heat-insulating substrate on which an electrode pattern is formed,
The procedure is the same as in Example 1 except that the material that thermally connects the side surface of the thermoelectric element and the substrate with the heat generation side electrode is not used.

In the thermoelectric cooling thermo-modules of Examples 1, 2 and 3 and the comparative example described above, the temperature difference between the surface of the heat generating side insulating substrate and the surface of the heat absorbing side insulating substrate is set to 0K, and the thermoelectric cooling service is set. The amount of heat absorption from the surface of the insulating substrate on the heat absorption side was measured when a current of 3 A and 5 A was applied to the module.

In the measuring method, the heat generating side insulating substrate was brought into contact with a heat sink in which cooling water was flown, and a heater was placed on the heat absorbing side insulating substrate. After passing the current through the thermo-module and the heater so that the heat generating side insulating substrate becomes 323K,
Heat so that the temperature difference between the surfaces of the insulating substrates on both sides becomes 0K.
The amount of power applied to the target was adjusted. In a stable state, the amount of electric power of the heater when the temperature difference between both insulating substrates became 0K was taken as the amount of heat absorption. Here, the measurement was performed in vacuum. The measurement results are shown in Table 1.

[0019]

[Table 1]

In each embodiment, among the four side surfaces of each thermoelectric element,
The two surfaces facing each other are covered with a copper plate, and the covering ratio is as in Example 1.
, 3/4 in the second embodiment, ½ in the second embodiment, and ¼ in the third embodiment.
Is. From the comparative example in which the thermoelectric element was not covered with the copper plate, when 3A was flowed in the order of Examples 3, 2, and 1, the heat absorption amounts were 2.02W, 2.11W, 2.24W, and 2.31W. Also, when 5 A is flowed, the endothermic amount is 2.65 W,
It became 2.90W, 3.22W and 3.47W.

As described above, the heat absorption amount can be increased by thermally connecting the side surface of the thermoelectric element and the heat generating side insulating substrate in which the electrode pattern is punched with a material having a higher thermal conductivity than the thermoelectric element. . In particular, the effect is great when the thermoelectric cooling thermomodule is used at a high current, and in this case, the larger the rate of covering the side surface of the thermoelectric element with the copper plate, the greater the effect. Further, since the thermoelectric element of the thermoelectric cooling thermomodule manufactured in the example is joined to the concave portion on the heat generating side, it is possible to prevent the element from being displaced during manufacturing.

[0022]

As described above, the thermoelectric cooling thermomodule of the present invention can not only prevent the displacement of the elements during manufacturing, but also improve the cooling efficiency.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an example of a thermoelectric cooling thermomodule according to the present invention.

FIG. 2 is a schematic perspective view showing a part of a heat generating side joint portion of a thermoelectric cooling thermomodule according to the present invention.

[Explanation of symbols]

 1 Thermoelectric Cooling Module 2 Heat Insulation Substrate 2a Flat Insulation Substrate 2b Insulation Substrate with Punched Electrode Pattern 2C Recess 3 Heat Absorption Insulation Substrate 4 Metal Electrode 5 Thermoelectric Element 5a n-type Thermoelectric Element 5b p Type thermoelectric element 6 Connection member

Claims (4)

[Claims] 1. A thermoelectric cooling thermo-module, wherein an electrode and a thermoelectric element are joined to a concave portion of the heat generating side insulating substrate which forms an electrode pattern. 2. The thermoelectric cooling thermo-module according to claim 1, wherein the depth of the concave portion of the heat generating side insulating substrate forming the electrode pattern is larger than the thickness of the electrode. 3. The concave portion forming the electrode pattern of the heat generating side insulating substrate is formed by joining a flat plate-shaped insulating substrate and an insulating substrate having a hole punched with the electrode pattern. The thermoelectric cooling thermomodule according to claim 1 or 2. 4. The thermoelectric cooling according to claim 1, wherein a side surface of the thermoelectric element and an insulating substrate for heat generation are thermally connected with a material having a higher thermal conductivity than the thermoelectric element. Thermo module.