JP2016031966A - Peltier element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a Peltier element capable of suppressing separation and damage of a thermoelectric conversion element as well as keeping performance without becoming large-sized.SOLUTION: A Peltier element comprises: a one side electrode part 3 formed on a one side substrate 1; an other side electrode part 4 formed on an other side substrate 2; a plurality of thermoelectric conversion elements 5 for transferring heat from the one side substrate 1 to the other side substrate 2 when receiving applied power; and an other side joint part 7 that has electric conductivity and joins the other side electrode part 4 to the thermoelectric conversion elements 5. The other side joint parts 7 are constructed so that a melting point of joint material 71 disposed on a first area A1 including at least four corner parts A0 of a rectangular element arrangement part A, of the other side substrate 2, on which the plurality of thermoelectric conversion elements 5 are arranged, is lower than a melting point of joint material 72 disposed on a second area A2 that is the area other than the first area A1 of the element arrangement part A.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a Peltier element.

  The Peltier element is a device that performs temperature adjustment (temperature adjustment) of an object using the Peltier effect of a thermoelectric conversion element. The Peltier element mainly includes one side substrate, the other side substrate, and a plurality of thermoelectric conversion elements arranged between the two substrates. When power is applied to the Peltier element, heat is transferred from the one side substrate to the other side substrate. At this time, the one side substrate absorbs heat and becomes low temperature, and the other side substrate dissipates heat and becomes high temperature. At this time, the other substrate expands due to heat, and stress is generated between the thermoelectric conversion element and the electrode of the other substrate. This stress may cause peeling between the thermoelectric conversion element and the electrode on the other substrate, or the thermoelectric conversion element may be damaged. If such disconnection or breakage occurs, the Peltier element will not function.

  Here, for example, Japanese Unexamined Patent Application Publication No. 2004-172216 describes a thermoelectric module in which thermoelectric conversion elements are not arranged at four corners. According to this thermoelectric module, since there are no thermoelectric conversion elements at the four corner portions that receive a large stress due to the displacement of the substrate, peeling and breakage of the thermoelectric conversion elements in the portions are prevented.

JP 2004-172216 A

  However, in the thermoelectric module, since the thermoelectric conversion elements are not arranged at the four corners, the heat absorption amount per unit area is reduced, and there is a problem of a decrease in cooling performance or an increase in the size of the module for ensuring performance.

  The present invention has been made in view of such circumstances, and provides a Peltier element that can maintain performance without increasing its size and can suppress peeling and breakage of a thermoelectric conversion element. For the purpose.

  The Peltier device of the present invention includes a one side substrate, the other side substrate, the one side electrode portion formed on the one side substrate, the other side electrode portion formed on the other side substrate, and the one side electrode portion. And a plurality of thermoelectric conversion elements that move heat from the one side substrate to the other side substrate when electric power is applied, and the one side electrode portion and the thermoelectric conversion element, A first side joint having conductivity, and a second side joint having conductivity to join the second electrode part and the thermoelectric conversion element, the second side joint being the second side In the rectangular element arrangement portion in which the plurality of thermoelectric conversion elements are arranged on the substrate, the melting point of the bonding material arranged in the first region including the four corner portions of the element arrangement portion is the element arrangement portion in the element arrangement portion. In the second area that is an area other than the first area It is configured to be lower than the melting point of the bonding material to be location.

  According to the Peltier device of the present invention, when the other side substrate becomes high temperature, the bonding material of the first region having a low melting point becomes softer than the bonding material of the second region, and the expansion of the other side substrate causes The displacement is absorbed by the flexibility of the bonding material in the first region. The first region is a region including the four corner portions where the stress is large, and peeling and breakage of the thermoelectric conversion element are effectively suppressed. And the fixing function of the thermoelectric conversion element is ensured by the bonding material in the second region. Further, according to the Peltier element of the present invention, the thermoelectric conversion elements are also arranged at the four corners of the element arrangement part, so that the performance can be maintained without increasing the size.

It is a block diagram which shows the structure of the Peltier device of 1st embodiment. It is plane explanatory drawing for demonstrating the internal structure of the Peltier device of 1st embodiment. It is a plane explanatory view for explaining the element arrangement portion of the first embodiment. It is a plane explanatory view for explaining the element arrangement portion of the modification of the first embodiment. It is plane explanatory drawing for demonstrating the element arrangement | sequence part of 2nd embodiment. It is a plane explanatory view for explaining an element arrangement portion of a third embodiment. It is plane explanatory drawing for demonstrating the element arrangement | sequence part of the deformation | transformation aspect of 3rd embodiment. It is plane explanatory drawing for demonstrating the element arrangement | sequence part of another deformation | transformation aspect. It is plane explanatory drawing for demonstrating the element arrangement | sequence part of another deformation | transformation aspect. It is plane explanatory drawing for demonstrating the element arrangement | sequence part of another deformation | transformation aspect. It is plane explanatory drawing for demonstrating the element arrangement | sequence part of another deformation | transformation aspect. It is plane explanatory drawing for demonstrating the element arrangement | sequence part of another deformation | transformation aspect. It is plane explanatory drawing for demonstrating the element arrangement | sequence part of another deformation | transformation aspect.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, the same or equivalent parts are denoted by the same reference numerals in the drawings. Each figure used for explanation is a conceptual diagram, and the shape of each part may not necessarily be exact. Further, in the drawings, reference numerals are given to parts of continuously arranged parts, and reference numerals are omitted for the other parts. In the present embodiment, a specific example in which “one” is “upper” and “other” is “lower” will be described. In addition, “connection” in an electrode, wiring, circuit, or the like means “electrical connection” even when there is no particular description.

<First embodiment>
As shown in FIGS. 1 to 3, the Peltier device of the first embodiment includes an upper insulating substrate (corresponding to “one side substrate”) 1, a lower insulating substrate (corresponding to “other side substrate”) 2, , An upper electrode part (corresponding to “one side electrode part”) 3, a lower electrode part (corresponding to “other side electrode part”) 4, a plurality of thermoelectric conversion elements 5, and an upper joint part (“one side”) 6) (corresponding to “side joining portion”) and a lower joining portion (corresponding to “other side joining portion”) 7.

  The upper insulating substrate 1 is a flat substrate made of an insulating member such as ceramic. The lower insulating substrate 2 is a flat substrate made of an insulating member such as ceramic, like the upper insulating substrate 1. The lower insulating substrate 2 faces the upper insulating substrate 1. The upper insulating substrate 1 and the lower insulating substrate 2 are both rectangular (here, square), and the areas of both are the same.

  The upper electrode portion 3 is formed on the lower surface of the upper insulating substrate 1 and is composed of a plurality of flat electrodes. The upper electrode portion 3 is disposed on the lower surface of the upper insulating substrate 1 as a whole in a rectangular shape (here, a square shape). Two thermoelectric conversion elements 5 are arranged on each electrode of the upper electrode portion 3, and both of them are connected by electrodes.

  The lower electrode portion 4 is formed on the upper surface of the lower insulating substrate 2 and is composed of a plurality of flat electrodes 4a and 4b. The lower electrode portion 4 is disposed in a rectangular shape (here, square shape) as a whole on the upper surface of the lower insulating substrate 2. The lower electrode portion 4 is disposed to face the upper electrode portion 3. Two thermoelectric conversion elements 5 are arranged on each electrode 4a of the lower electrode portion 4, and both of them are connected by the electrode 4a. The two electrodes 4b of the lower electrode part 4 are each provided with one thermoelectric conversion element 5, and the external wiring 8 is connected to each vacant space.

  The thermoelectric conversion element 5 is an element that converts heat and electric power. The thermoelectric conversion elements 5 are formed in a prismatic shape that can be disposed on the electrode of the upper electrode part 3 and the electrode 4 a of the lower electrode part 4. The thermoelectric conversion element 5 is disposed between the upper electrode part 3 and the lower electrode part 4. All the thermoelectric conversion elements 5 are arranged in a rectangular shape as a whole on the lower insulating substrate 2. The rectangular portion (region) in the lower insulating substrate 2 is referred to as “element array portion A”. The element array portion A can be said to be a rectangular region formed on the portion where the lower electrode portion 4 is arranged, that is, on the upper surface of the lower electrode portion 4. In the first embodiment, since the thermoelectric conversion element 5 is disposed on the entire upper surface of the lower insulating substrate 2, the entire upper surface of the lower insulating substrate 2 is an element array portion A.

  The plurality of thermoelectric conversion elements 5 are configured by alternately arranging p-type semiconductors and n-type semiconductors. The upper electrode part 3, the lower electrode part 4, and the plurality of thermoelectric conversion elements 5 form one circuit. When electric power is supplied to the Peltier element from the external wiring 8, heat is transferred from the upper insulating substrate 1 to the lower insulating substrate 2 by the thermoelectric conversion element 5 in the circuit. That is, the upper insulating substrate 1 is the heat absorption side, and the lower insulating substrate 2 is the heat dissipation side, that is, the high temperature side.

  The upper bonding portion 6 is a conductive bonding material (conductive bonding material) that bonds the upper electrode portion 3 and the thermoelectric conversion element 5. The upper joint portion 6 of the first embodiment is composed of one kind of joining material and has one melting point. The bonding material is, for example, a brazing material, solder, or an adhesive, and is determined according to the temperature environment (temperature range due to use) of the Peltier elements (substrates 1 and 2). For example, when the Peltier element is used in a temperature environment ranging from room temperature to about 200 ° C., a bonding material having a melting point of about 240 ° C. (for example, solder with a composition of 95 Sn, 5Sb) is adopted as the bonding material for the upper bonding portion 6. it can. In the first embodiment, a paste-like bonding material is used, and the application to the upper bonding portion 6 to the upper electrode portion 3 is performed by screen printing, for example.

  The lower bonding portion 7 is a conductive bonding material (conductive bonding material) for bonding the lower electrode portion 4 and the thermoelectric conversion element 5. The lower joint portion 7 of the first embodiment is composed of two types of joining materials, and has different melting points depending on the place of application. The bonding material is, for example, a brazing material, solder, or an adhesive, similar to the upper bonding portion 6, and is determined according to the temperature environment of the substrates 1 and 2.

  Specifically, the lower bonding portion 7 includes a first bonding material 71 and a second bonding material 72, as shown in FIG. The first bonding material 71 is applied to the portions represented by black and white dot hatches on the electrodes 4a and 4b in the drawing, and the second bonding material 72 is applied to the portions represented by white lines on the electrodes 4a in the drawing. Has been.

  The first bonding material 71 is disposed in the first region A1 including at least the four corner portions A0 of the element array portion A. That is, the first bonding material 71 bonds and connects the thermoelectric conversion element 5 disposed in the first region A1 and the electrodes 4a and 4b of the lower electrode portion 4 disposed in the first region A1. The melting point of the first bonding material 71 is lower than the melting point of the second bonding material 72. For example, when the Peltier element is used in a temperature environment ranging from room temperature to about 200 ° C., a bonding material having a melting point of about 170 ° C. (for example, solder having a composition of 99Sn, 1Ge) can be adopted as the first bonding material 71.

  The second bonding material 72 is disposed in the second region A2 that is a region other than the first region A1 of the element array portion A. The melting point of the second bonding material 72 is higher than the melting point of the first bonding material 71. As the second bonding material 72, a bonding material that can reliably maintain the bonding state according to the temperature environment is used. The second bonding material 72 of the first embodiment is the same as the upper bonding portion 6 and the bonding material. The lower joint portion 7 is in a paste form, and is applied to the lower electrode portion 4 by, for example, screen printing or a dispenser. The bonding temperature can be the same as the bonding temperature on the high melting point side, that is, the bonding temperature of the second bonding material 72.

  Here, the element array portion A will be described in detail. As described above, the element array portion A includes the first region A1 in which the low-melting-point first bonding material 71 is disposed and the second region A2 in which the high-melting-point second bonding material 72 is disposed. Yes. The first area A1 is an area including a portion represented by a black and white dot hatch on the electrodes 4a and 4b in FIG. 2nd area | region A2 is an area | region containing the part represented by white on the electrode 4a in FIG.

  As shown in FIG. 3, the second region A <b> 2 of the first embodiment is formed in a circular shape with the center portion of the element array portion A as the center. In the first embodiment, the element array portion A is formed in a square shape, and the second region A2 is formed in a circular shape whose diameter is the length of one side of the element array portion A.

  The circular shape of the second region A2 is, for example, a thermoelectric conversion element 5 arranged inside the virtual circle (see dotted line) when a virtual circle is arranged on the element arrangement portion A around the center portion of the element arrangement portion A. It may be configured. Or the circular shape of 2nd area | region A2 is comprised by the thermoelectric conversion element 5 which the virtual circle (refer dotted line) passed (overlapped) and the thermoelectric conversion element 5 inside a virtual circle, for example, as shown in FIG. May be. Here, “circular shape” means a shape based on a circular or elliptical locus.

  The first region A1 includes four regions (independent regions) located at the corners (corner portions) of the element array portion A. Each independent area | region here is formed in the concave arc shape (or triangular shape). The first region A1 is formed in line symmetry with respect to a straight line (see the alternate long and short dash line) that passes through the midpoint of one side of the element array portion A and is orthogonal to the one side. In addition, about the shape of 1st area | region A1, such as circular shape and line symmetry, slight differences, such as the presence or absence of the very few thermoelectric conversion elements 5, with respect to the whole are permitted and are included in this embodiment.

  According to the Peltier device of the first embodiment, when the lower insulating substrate 2 becomes high temperature, the first bonding material 71 in the first region A1 having a low melting point is more than the second bonding material 72 in the second region A2. It becomes soft first, and the displacement due to the expansion of the lower insulating substrate 2 is absorbed by the flexibility of the first bonding material 71. In other words, the stress in the first region A1 is dispersed and released by the first bonding material 71 having a low melting point. In addition, the lower bonding portion 7 is not softened as a whole, and the fixing function of the thermoelectric conversion element 5 is secured by the bonding material in the second region having a high melting point, that is, the second bonding material 72. It can be said that the element array portion A has a movable region (first region A1) and a fixed region (second region A2).

  In the element arrangement portion A where heat is generated, the four corner portions A0 that are relatively far from the center of the element arrangement portion A are portions where stress generated between the thermoelectric conversion element 5 and the lower electrode portion 4 due to heat is large. is there. In other words, the four corner portions A0 are portions where the displacement (expansion) of the lower insulating substrate 2 is large. The first region A1 is a region including at least the four corner portions A0, and the first bonding material 71 having a low melting point is disposed in the first region A1. Thereby, peeling and breakage of the thermoelectric conversion element 5 are effectively suppressed. Furthermore, according to the Peltier device of the first embodiment, since the thermoelectric conversion elements 5 are also arranged at the four corner portions A0 of the element arrangement portion A, the performance can be maintained without increasing the size.

  In the first embodiment, the lower joint portion 7 is composed of two types of joining materials having different melting points, and the upper joint portion 6 is joined to the second joint material 72 of the lower joint portion 7 in the same manner. The material is used. For this reason, only two types of bonding materials are used for the Peltier element as a whole, which facilitates manufacturing and suppresses an increase in manufacturing cost. In addition, even if the upper side joining part 6 is a joining material different from the joining material used in the lower side joining part 7, the lower side joining part 7 is composed of two kinds of joining materials. Can be easily formed, and an increase in manufacturing cost can be suppressed.

  In addition, since the first region A1 is formed line-symmetrically as described above, the distance from the central portion of the element array portion A is equal on the left and right and / or top and bottom, and stress concentration is suppressed. That is, peeling and breakage of the thermoelectric conversion element 5 are effectively suppressed. Furthermore, in the first embodiment, since the second region A2 is formed in a circular shape centering on the central portion of the element array portion A, the stress is evenly distributed and the stress concentration is further suppressed. Thereby, peeling and damage of the thermoelectric conversion element 5 are suppressed more effectively. Further, the Peltier element of the first embodiment is in a form in which the second region A2 is in contact with the end (side) of the element array portion A, which is advantageous in terms of fixing force and stability of the thermoelectric conversion element 5.

<Second embodiment>
The Peltier device of the second embodiment is different from the first embodiment in the shape of the first region and the second region. Therefore, different parts will be described, and the same components as those in the first embodiment will be denoted by the same reference numerals and description thereof will be omitted.

  As shown in FIG. 5, the element array portion A of the second embodiment includes a first region A10 and a second region A20. The first region A10 includes a rectangular (here rectangular) region A11 arranged along the first side a1 of the element array portion A, and a third side a3 of the element array portion A (the opposite side of the side a1). ) Arranged in a rectangular shape (in this case, a rectangular shape) A12. In other words, the first region A10 is a two-row rectangular region that is arranged in parallel and spaced from the second side a2 to the fourth side a4 (the opposite side of the side a2). The first area A1 includes two rectangular areas (independent areas) that are not connected to each other. The 1st joining material 71 is apply | coated to the thermoelectric conversion element 5 arrangement position in 1st area | region A10.

  The second region A20 is formed in a rectangular shape (here, a rectangular shape) including the central portion of the element array portion A. The second region A20 extends from the side a2 to the side a4 of the element array portion A. The 2nd joining material 72 is apply | coated to the thermoelectric conversion element 5 arrangement position in 2nd area | region A20. Also by the Peltier device of the second embodiment, the first region A10 becomes a movable region, and the second region A20 becomes a fixed region, so the same effect as the first embodiment is exhibited.

  In the second embodiment, the second region A20 is not circular, but is formed in a rectangular shape extending from one side to the opposite side. According to this structure, the element arrangement | sequence part A is comprised by the rectangular area | region of 3 rows by 1st area | region A10 and 2nd area | region A20 (namely, 2 types of joining materials). Thereby, screen printing becomes easy, an increase in manufacturing cost is suppressed, and work efficiency is improved. Further, the second region A20 comes into contact with the end portion (side) of the element array portion A, which is advantageous in terms of fixing force and stability of the thermoelectric conversion element 5. However, in terms of suppressing stress concentration, the arrangement (circular shape) of the second region A2 of the first embodiment is excellent. In addition, when the element arrangement | sequence part A is rectangular shape, each area | region A11, A12 and / or 2nd area | region A20 of 1st area | region A10 may be square shape.

<Third embodiment>
The Peltier device of the third embodiment is different from the first embodiment in terms of the shapes of the first region and the second region. Therefore, different parts will be described, and the same components as those in the first embodiment will be denoted by the same reference numerals and description thereof will be omitted.

  As shown in FIG. 6, the element array portion A of the third embodiment includes a first region A100 and a second region A200. The second region A200 is formed in a rhombus shape (here, a shape obtained by rotating a square shape by 45 degrees) with the center portion coinciding with the center portion of the element array portion A. The second area A200 is set based on a rhombus locus (see dotted line). The first region is configured by connecting four triangular regions located at the corners (corner portions) of the element array portion A. The first region A1 is formed in line symmetry with respect to a straight line (see the alternate long and short dash line) that passes through the midpoint of one side of the element array portion A and is orthogonal to the one side. A first bonding material 71 having a low melting point is applied to the first region A100, and a second bonding material 72 having a high melting point is applied to the second region A200.

  According to the Peltier device of the third embodiment, the same effect as the first embodiment is exhibited. Further, since the second region A200 has a rhombus shape whose central portion is the same as that of the element array portion A, a uniform triangular first region A100 is formed at each corner portion constituting the four corner portions A0. According to this configuration, the bonding material can be arranged more easily than the circular shape, and stress can be effectively released. The angle of each corner of the rhombus does not have to be 90 degrees.

  In addition, as shown in FIG. 7, the first region A100 may be configured with four triangular regions (independent regions) that are not connected to each other. In this case, the second region A200 comes into contact with the end (side) of the element array portion A, which is advantageous in terms of fixing force and stability of the thermoelectric conversion element 5.

<Other variations>
The present invention is not limited to the above embodiment. For example, the upper joint portion 6 may be composed of a plurality of joining materials. The lower joint 7 may be composed of three or more kinds of joining materials. Also in this case, the melting point of the bonding material applied to the four corner portions A0 is the lowest among the lower bonding portions 7. Further, the lower bonding portion 7 may have three or more types of bonding materials, and a configuration in which a bonding material having a high melting point is arranged toward the center of the element array portion A may be used. Further, the upper bonding portion 6 may be a bonding material different from the second bonding material 71.

  The element array portion A may be rectangular. The second area A2 may be elliptical. When the element array portion A is rectangular, for example, the second region A2 may be elliptical by matching the longitudinal direction. Further, each corner of the four corner portions A0 may be in a position corresponding to one or a plurality of thermoelectric conversion elements 5 disposed in the corner, and corresponds to one or a plurality of electrodes 4a and 4b disposed in the corner. It may be the position to do. When the external wiring 8 is in a corner, at least one of the thermoelectric conversion elements 5 arranged around the portion to which the external wiring 8 is connected corresponds to the position of one corner of the four corner portion A0. Moreover, 1st area | region A1, A10, A100 does not need to be line symmetrical.

  Further, the first regions A1 and A100 may be configured such that there are one, two, or four independent regions. For example, as shown in FIG. 8, the first region A1 may have two independent regions formed by connecting two adjacent corner regions. For example, as shown in FIG. 9, the first area A <b> 1 may be composed of one independent area in which four corner areas are connected.

  Moreover, the structural example of the element arrangement | sequence part A of this invention is represented to FIGS. Even with these configurations, since the first region A1 and the second region A2 exist, performance can be maintained without increasing the size of the Peltier element, and peeling and breakage of the thermoelectric conversion element 5 can be suppressed. .

  As described above, the Peltier device of the present embodiment includes the one-side substrate 1, the other-side substrate 2, the one-side electrode portion 3 formed on the one-side substrate 1, and the other formed on the other-side substrate 2. A plurality of thermoelectric elements arranged between the side electrode part 4 and the one side electrode part 3 and the other side electrode part 4 to transfer heat from the one side substrate 1 to the other side substrate 2 when electric power is applied. The conversion element 5, the one-side bonding part 6 having conductivity for bonding the one-side electrode part 3 and the thermoelectric conversion element 5, and the conductivity for bonding the other-side electrode part 4 and the thermoelectric conversion element 5. The other-side bonding portion 7, and the other-side bonding portion 7 includes the element arrangement in the rectangular element arrangement portion A in which the plurality of thermoelectric conversion elements 5 are arranged on the other-side substrate 2. First regions A1, A10 including at least the four corner portions A0 of the portion A, The melting point of the bonding material 71 disposed in 100 is the melting point of the bonding material 72 disposed in the second regions A2, A20, A200, which are regions other than the first regions A1, A10, A100 in the element array portion A. It is comprised so that it may become lower.

  Moreover, the said other side joining part 7 is comprised by two types of joining materials 71 and 72, and the said one side joining part 6 is the same joining as the joining material 72 arrange | positioned in said 2nd area | region A2, A20, A200. It is a material. The first regions A1, A10, A100 are formed symmetrically with respect to a straight line that passes through the midpoint of one side of the element array portion A and is orthogonal to the one side. The second regions A2 and A200 are formed in a circular shape centered on the central portion of the element array portion A. Further, the other side joining portion 7 is composed of two kinds of joining materials 71 and 72, and the first region A10 is a rectangular region A11 arranged along one side a1 of the element array portion A, and And a rectangular region A12 disposed along the opposite side a3 of the one side a1 of the element array portion A, and the second region A20 is formed in a rectangular shape including the central portion of the element array portion A. Has been.

1: upper insulating substrate (one side substrate), 2: lower insulating substrate (other side substrate),
3: upper electrode part (one side electrode part), 4: lower electrode part (other side electrode part),
5: Thermoelectric conversion element 5, 6: Upper joint (one side joint),
7: Lower joint (the other joint), 71: First joint, 72: Second joint,
A: element arrangement portion, A0: four corner portions, A1, A10, A100: first region,
A2, A20, A200: Second region

Claims (5)

One side substrate;
The other substrate,
One side electrode portion formed on the one side substrate;
The other electrode portion formed on the other substrate;
A plurality of thermoelectric conversion elements that are arranged between the one side electrode portion and the other side electrode portion and move heat from the one side substrate to the other side substrate when power is applied;
One side joint having conductivity to join the one side electrode part and the thermoelectric conversion element;
The other side joint having conductivity to join the other side electrode part and the thermoelectric conversion element;
With
In the rectangular element arrangement portion where the plurality of thermoelectric conversion elements are arranged on the other substrate, the other side joining portion is a bonding material arranged in a first region including at least four corner portions of the element arrangement portion. The Peltier element is configured such that the melting point of the bonding material disposed in the second region other than the first region in the element array portion is lower than the melting point of the bonding material. The other side joining portion is composed of two kinds of joining materials,
The Peltier device according to claim 1, wherein the one-side joint is the same joint material as the joint material disposed in the second region.   3. The Peltier element according to claim 1, wherein the first region is formed in line symmetry with respect to a straight line that passes through a midpoint of one side of the element array portion and is orthogonal to the one side.   The Peltier device according to any one of claims 1 to 3, wherein the second region is formed in a circular shape centering on a central portion of the element array portion. The other side joining portion is composed of two kinds of joining materials,
The first region is composed of a rectangular region disposed along one side of the element array portion and a rectangular region disposed along the opposite side of the one side of the element array portion,
The Peltier device according to any one of claims 1 to 3, wherein the second region is formed in a rectangular shape including a central portion of the element arrangement portion.

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