JP2014049587A - Thermoelectric module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermoelectric module which inhibits peeling of a wiring conductor and thereby inhibits cracks from occurring on a support substrate.SOLUTION: A thermoelectric module of this invention comprises: a pair of support substrates 1 which are disposed facing each other; wiring conductors 2 which are respectively provided on facing one-side main surfaces of the pair of the support substrates 1; multiple thermoelectric elements 3 which are aligned between the facing one-side main surfaces of the pair of the support substrates 1 so as to be electrically connected with each other by the wiring conductors 2; and a heat exchange member 5 which is attached to the other-side main surface of at least one of the pair of the support substrates 1 through a joining material layer 4. The joining material layer 4 has a thick region 41 at a portion located at the outer peripheral side of the other-side main surface.

Description

  The present invention relates to a thermoelectric module suitably used for cooling a heating element such as a semiconductor.

  Thermoelectric elements using the Peltier effect are used as thermoelectric modules for temperature control of laser diodes, thermostats, cooling in refrigerators, and the like.

The thermoelectric module for cooling used near room temperature is a P-type formed of a thermoelectric material made of A ₂ B ₃ type crystal (A is Bi and / or Sb, B is Te and / or Se) having excellent cooling characteristics. The thermoelectric element and the N-type thermoelectric element are paired. For example, as a thermoelectric material exhibiting particularly excellent performance, a thermoelectric material made of a solid solution of Bi ₂ Te ₃ (bismuth telluride) and Sb ₂ Te ₃ (antimony telluride) is used for a P-type thermoelectric element, and N A thermoelectric material made of a solid solution of Bi ₂ Te ₃ (bismuth telluride) and Bi ₂ Se ₃ (bismuth selenide) is used for the thermoelectric element of the type.

  In the conventional thermoelectric module, for example, a P-type thermoelectric element formed of such a thermoelectric material and an N-type thermoelectric element are electrically connected in series, and each of the P-type thermoelectric element and the N-type thermoelectric element is connected. Are arranged between a pair of supporting substrates made of ceramics or the like having a wiring conductor formed on the surface, the P-type thermoelectric element and the N-type thermoelectric element and the wiring conductor are joined with solder, and the other main of each of the pair of supporting substrates It is produced by bonding a metal plate or a heat exchange member to the surface via a bonding material layer (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 7-7187

  However, in the thermoelectric module having a shape as shown in Patent Document 1, stress generated due to deformation during use is concentrated on the interface between the wiring conductor and the support substrate provided at the peripheral edge of the support substrate, and the support substrate As a result, the wiring conductor and the thermoelectric element peel off from each other, or cracks are generated in the support substrate triggered by the peeling, resulting in a deterioration in cooling performance.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a thermoelectric module in which peeling of wiring conductors and thermoelectric elements is suppressed and cracks are suppressed from being generated on a support substrate.

  The thermoelectric module of the present invention includes a pair of support substrates disposed so as to face each other, wiring conductors respectively provided on one opposing main surface of the pair of support substrates, and one of the pair of support substrates facing each other A plurality of thermoelectric elements arranged so as to be electrically connected by the wiring conductor between the main surfaces, and attached to the other main surface of at least one of the pair of support substrates via a bonding material layer A heat exchange member, and the bonding material layer has a thick region at a portion on the outer peripheral side of the other main surface.

  The thermoelectric module of the present invention is characterized in that, in the above-described configuration, the bonding material layer gradually decreases in thickness from the thick region toward the inside.

  In the thermoelectric module of the present invention, in the configuration described above, the heat exchange member is adjacent to a plurality of bottom portions that are in contact with the bonding material layer, a plurality of standing portions that are erected from the plurality of bottom portions, respectively. And a plurality of top surface portions that connect the standing portions to each other, and the plate-like body is bent so as to meander when viewed in cross section.

  Further, the thermoelectric module of the present invention, in the above-described configuration, includes a plurality of regions provided independently of each other so that the bonding material layer corresponds to the plurality of bottom portions, and the thick region is the heat exchange It is provided corresponding to the bottom face part located in the end of the direction of meandering of a member.

  The thermoelectric module of the present invention is characterized in that, in the above configuration, the thick region is divided into a plurality of regions in a direction perpendicular to the meandering direction.

  Moreover, the thermoelectric module of the present invention is characterized in that, in the above configuration, the plurality of top surface portions of the heat exchange member are flush with each other.

  Moreover, the thermoelectric module of the present invention is characterized in that, in the above configuration, the standing portion located at the end of the heat exchange member is inclined inward.

  The thermoelectric module of the present invention is characterized in that, in the above configuration, the plurality of top surface portions of the heat exchange member are covered with a case.

  According to the present invention, peeling of the wiring conductor and the thermoelectric element can be suppressed, and cracks can be prevented from being generated in the support substrate, so that a thermoelectric module having excellent durability and suppressing deterioration in cooling performance can be obtained.

(A) is sectional drawing which shows an example of embodiment of the thermoelectric module of this invention, (b) is a principal part expanded sectional view of the thermoelectric module shown to (a). It is the perspective view which decomposed | disassembled some thermoelectric modules shown in FIG. (A) is sectional drawing which shows the other example of embodiment of the thermoelectric module of this invention, (b) is a principal part expanded sectional view of the thermoelectric module shown to (a). It is a principal part expanded sectional view which shows the other example of embodiment of the thermoelectric module of this invention. It is a principal part expanded sectional view which shows the other example of embodiment of the thermoelectric module of this invention. It is a principal part expanded sectional view which shows the other example of embodiment of the thermoelectric module of this invention. It is a principal part expanded sectional view which shows the other example of embodiment of the thermoelectric module of this invention. It is a principal part expanded sectional view which shows the other example of embodiment of the thermoelectric module of this invention. It is a principal part expanded sectional view which shows the other example of embodiment of the thermoelectric module of this invention.

  Hereinafter, an example of an embodiment of a thermoelectric module of the present invention will be described based on the drawings.

  FIG. 1A is a schematic cross-sectional view showing an example of an embodiment of a thermoelectric module of the present invention, and FIG. 1B is an enlarged view of a main part of the thermoelectric module shown in FIG. FIG. 2 is an exploded perspective view of a part of the thermoelectric module shown in FIG.

  The thermoelectric module shown in FIG. 1 includes a pair of support substrates 1 arranged to face each other, a wiring conductor 2 provided on one main surface of the pair of support substrates 1 facing each other, and a pair of support substrates 1. A plurality of thermoelectric elements 3 arranged so as to be electrically connected by wiring conductors 2 between one opposing main surfaces, and a bonding material layer on the other main surface of at least one support substrate 1a of the pair of support substrates 1 The bonding material layer 4 has a thick region 41 at a site on the outer peripheral side of the other main surface.

  A pair of support substrates 1 (1a, 1b) arranged so as to face each other are bonded with a copper plate on the other main surface (outer main surface) of an epoxy resin plate (substrate body) to which, for example, an alumina filler is added. The substrate (for example, a substrate on which a copper plate having a thickness of 100 to 500 μm is bonded) is arranged so that the support substrates 1a and 1b face each other. The copper plate is for increasing the thermal conductivity of the support substrate 1 (1a, 1b). For example, the copper plate is formed in a pattern (so-called solid pattern) covering almost the entire surface of the other main surface.

  The pair of support substrates 1 (1a, 1b) are formed to have a size in a plan view of, for example, 40 to 50 mm in length and 20 to 40 mm in width, and a thickness of, for example, 0.05 to 2.0 mm. Is. The support substrate 1 may have a configuration in which a metal plate such as copper is bonded to the outer main surface of a substrate body made of a ceramic material such as alumina or aluminum nitride, such as copper, silver, or silver-palladium. Alternatively, an insulating layer made of epoxy resin, polyimide resin, alumina, aluminum nitride, or the like may be provided on the inner main surface of the substrate body made of the conductive material.

  A wiring conductor 2 is provided on each of the opposing main surfaces (inner main surfaces) of the pair of support substrates 1 (1a, 1b). The wiring conductor 2 is formed, for example, by etching a copper plate bonded to one main surface (inner main surface) of the support substrate 1 into a wiring pattern, and adjacent P-type thermoelectric elements 3a and N-type thermoelectric elements. 3b is provided so as to be electrically connected in series. The material for forming the wiring conductor 2 is not limited to copper, and may be a material such as silver or silver-palladium.

A plurality of thermoelectric elements 3 (P-type thermoelectric elements 3a and N-type thermoelectric elements 3b) are electrically connected by wiring conductors 2 between the opposing main surfaces of the pair of support substrates 1 (1a, 1b). It is arranged. The thermoelectric element 3 (P-type thermoelectric element 3a, N-type thermoelectric element 3b) is a thermoelectric material made of A ₂ B ₃ type crystal (A is Bi and / or Sb, B is Te and / or Se), preferably bismuth ( Bi) The main body is formed of a tellurium (Te) thermoelectric material. Specifically, the P-type thermoelectric element 3a is formed of, for example, a thermoelectric material made of a solid solution of Bi ₂ Te ₃ (bismuth telluride) and Sb ₂ Te ₃ (antimony telluride), and the N-type thermoelectric element 3b is For example, it is formed of a thermoelectric material made of a solid solution of Bi ₂ Te ₃ (bismuth telluride) and Bi ₂ Se ₃ (bismuth selenide).

Here, the thermoelectric material to be the P-type thermoelectric element 3a is a P-type forming material composed of Bi _, Sb and Te once melted and solidified in one direction by the Bridgman method, for example, a cross section having a diameter of 1 to 3 mm. It is a circular rod-shaped body. Further, the thermoelectric material to be the N-type thermoelectric element 3b is an N-type forming material composed of Bi, Te and Se once melted and solidified in one direction by the Bridgman method, for example, a cross section having a diameter of 1 to 3 mm. It is a circular rod-shaped body.

  After coating a resist for preventing the plating from adhering to the side surfaces of these thermoelectric materials, the wire is cut into a width of, for example, 0.3 to 5.0 mm using a wire saw. Next, the Ni layer is formed only on the cut surface by, for example, electrolytic plating, the Sn layer is formed thereon, and the resist is peeled off with the solution, whereby the thermoelectric element 3 (P-type thermoelectric element 3a, N-type thermoelectric element). 3b) can be obtained.

  The shape of the thermoelectric element 3 (P-type thermoelectric element 3a, N-type thermoelectric element 3b) may be cylindrical, quadrangular, or polygonal, but in order to avoid stress concentration associated with expansion and contraction during use, A columnar shape is preferred.

  As shown in FIG. 2, a plurality of the thermoelectric elements 3 are arranged vertically and horizontally, for example, at intervals of 0.5 to 2.0 mm and 0.5 to 2.0 times the thermoelectric element size (diameter). The thermoelectric elements 3 (P-type thermoelectric element 3a and N-type thermoelectric element 3b) are joined to the wiring conductor 2 by a solder paste applied in the same pattern as the wiring conductor 2, and a plurality of thermoelectric elements 3 arranged in the wiring The conductors 2 are electrically connected in series.

  A heat exchange member 5 is attached to the other main surface (outer main surface) of at least one support substrate 1a of the pair of support substrates 1 with a bonding material layer 4 interposed therebetween. In FIGS. 1 and 2, a heat exchange member 5 is attached to the other main surface of both support substrates 1 a and 1 b via a bonding material layer 4.

  As the bonding material layer 4, for example, Sn—Bi solder, Sn—Sb solder, Sn—Ag—Cu solder, or the like is used.

  As the heat exchange member 5, copper, aluminum, iron or the like having high thermal conductivity is usually used. For applications in the region exceeding 1000 ° C. (for example, thermoelectric power generation used in a waste heat furnace or the like), silicon nitride or the like is used. Ceramics are also used. The heat exchange member 5 has a shape on the base as shown in the figure so as to increase the surface area per unit area in order to transfer heat to a liquid such as water or an organic solvent, or a gas such as air or nitrogen. A shape in which a plurality of fins are erected is preferable.

  Further, as shown in FIG. 3, the heat exchange member 5 includes a plurality of bottom portions 51 that are in contact with the bonding material layer 4, and a plurality of standing portions 52 that are respectively erected from the plurality of bottom portions 51. It is preferable that the plate-like body is bent so as to meander when viewed in a cross section, and a so-called corrugated fin is preferable. This is preferable in that the heat exchange efficiency can be increased, and the rigidity of the heat exchange member 5 can be lowered and moved flexibly to relieve stress.

  And the joining material layer 4 has the area | region 41 with thick thickness in the site | part used as the outer peripheral side of the other main surface. If the thickness of the bonding material layer 4 is uniform, the stress generated due to deformation during use is concentrated on the interface between the wiring conductor 2 and the support substrate 1 provided at the peripheral edge of the support substrate, and from the support substrate 1. Although there is a possibility that the wiring conductor 2 and the thermoelectric element 3 may be peeled off, such a configuration increases the degree of freedom of plastic deformation such as shearing of the bonding material layer 4 such as solder and weakens the restraint of thermal deformation of the support substrate 1. Therefore, the stress between the wiring conductor 2 and the support substrate 1 can be reduced, and therefore, the peeling of the wiring conductor 2 and the thermoelectric element 3 from the support substrate 1 can be suppressed. Therefore, it can be set as the thermoelectric module which has outstanding durability and suppressed the fall of cooling performance.

As the thickness of the bonding material layer 4, for example, the thickness of the inner region is 10 to 80 μm, whereas it is effective that the thick region 41 is 10 to 80 μm thicker than the inner region. is there. Moreover, it is effective that the width | variety (distance from an edge part) of the thick area | region 41 is 100-2000 micrometers. Further, having the thick region 41 at the outer peripheral side of the other main surface of the support substrate 1 is a configuration having the thick region 41 at the entire peripheral edge of the support substrate 1. However, it may be configured to have a thick region 41 in a portion along a side corresponding to both ends in the left-right direction in FIGS. 1 (a) and 3 (a).

  For example, in the case of the heat exchange member 5 having a shape in which a plurality of fins are erected on the base (plate-shaped portion) as shown in FIG. 1, a thick region 41 may be provided on the entire peripheral edge. The thick region 41 may be provided only in a portion along a side corresponding to both end portions in the left-right direction. Further, in the case of the heat exchange member 5 having a repeatedly bent fin shape (corrugated fin) as shown in FIG. 3, the thick region 41 is provided only in the portion along the side corresponding to both ends in the repeated bending direction. You may have.

  Moreover, as shown in FIG. 4, it is preferable that the bonding material layer 4 between the support substrate 1 and the heat exchange member 5 gradually decreases in thickness from the thick region 41 toward the inside. In other words, it is preferable that the thickness of the bonding material layer 4 gradually increases toward the end of the support substrate 1. As a result, stress concentration such as shearing on the bonding surface at the peripheral edge of the bonding material layer 4 can be relaxed, so that the wiring conductor 2 and the thermoelectric element 3 can be prevented from peeling off from the support substrate 1.

  Further, as shown in FIG. 5, the bonding material layer 4 is composed of a plurality of regions provided independently of each other so as to correspond to the plurality of bottom surface portions 51, and the thick region 41 meanders the heat exchange member 5. It is preferable to be provided corresponding to the bottom surface portion 51 located at the end in the direction. Thereby, since the increase in rigidity due to the bonding material layer 4 can be avoided, it is possible to suppress peeling of the wiring conductor 2 and the thermoelectric element 3 from the support substrate 1.

  Moreover, as shown in FIG. 6, it is preferable that the thick region 41 is divided into a plurality of regions in a direction perpendicular to the meandering direction. As a result, the bonding material layer 4 is divided even at one bottom surface portion 51, and the rigidity of the bonding material layer 4 can be further reduced, and the peeling of the wiring conductor 2 and the thermoelectric element 3 from the support substrate 1 is suppressed. be able to.

  Moreover, as shown in FIG. 7, it is preferable that the several top surface part 53 in the heat exchange member 5 is flush. As a result, as shown in FIG. 8, when the thermoelectric module is in a state where a plurality of top surface portions 53 are covered with the case 6 (thermoelectric module accommodated in the case 6), the contact with the volume of the space. By increasing the ratio of the area, the heat exchange efficiency can be improved.

  For example, as shown in FIG. 8, the case 6 is a cylindrical body having one end and the other end opened in a direction perpendicular to the meandering direction of the heat exchange member 5, and allows fluid to pass from one end to the other end. It has a structure that can

  Here, by shortening the standing portion 52 located at the end of the heat exchange member 5, the thickness of the bonding material layer 4 at the corresponding portion can be increased and the plurality of top surface portions 53 can be flush with each other. it can. Thereby, since the thick bonding material layer 4 can be secured, peeling of the thermoelectric element 3 from the support substrate 1 can be suppressed.

  Moreover, as shown in FIG. 9, the standing part 52 located at the end of the heat exchange member 5 may be inclined inward. Accordingly, the plurality of top surface portions 53 can be flush with each other, and the degree of freedom of deformation such as bending due to thermal stress of the support substrate can be increased, so that peeling of the thermoelectric element from the support substrate can be suppressed. .

  The thermoelectric module described above can be manufactured as follows.

  First, the thermoelectric element 3 (P-type thermoelectric element 3a and N-type thermoelectric element 3b) and the support substrate 1 are joined.

  Specifically, a solder paste is applied to at least a part of the wiring conductor 2 formed on the support substrate 1 (1b) to form a solder layer. Here, as a coating method, a screen printing method using a metal mask or a screen mesh is preferable in terms of cost and mass productivity.

  Next, the thermoelectric elements 3 are arranged on the surface of the wiring conductor 2 on which the solder layer is formed. The thermoelectric element 3 needs to arrange two types of elements, a P-type thermoelectric element 3a and an N-type thermoelectric element 3b. Any known technique may be used as a joining method, but the P-type thermoelectric element 3a and the N-type thermoelectric element 3b are arranged by a transfer method in which each of the P-type thermoelectric element 3a and the N-type thermoelectric element 3b is separately transferred to a jig that has been drilled. After that, a method of transferring and arranging on the support substrate 1 (1b) is simple and preferable.

  After the thermoelectric elements 3 (P-type thermoelectric elements 3a and N-type thermoelectric elements 3b) are arranged on the support substrate 1 (1b), the thermoelectric elements 3 (P-type thermoelectric elements 3a and N-type thermoelectric elements 3b) are opposite to the upper surface. The support substrate 1 (1a) is installed.

  Specifically, a solder layer is formed on the surface of the wiring conductor 2 on the upper surface of the thermoelectric elements 3 (P-type thermoelectric element 3a and N-type thermoelectric element 3b) arranged on the wiring conductor 2 provided on the support substrate 1b. The formed support substrate 1a is soldered by a known technique. The soldering method may be any of reflow oven or heating with a heater. However, when resin is used for the support substrate 1, the solder and the thermoelectric element 3 (P-type thermoelectric element 3a) may be heated while applying pressure to the upper and lower surfaces. And N-type thermoelectric element 3b) is preferable for improving the adhesion.

  Next, the heat exchange member 5 is attached to at least one (preferably both) of the pair of support substrates 1 (1a, 1b) with the bonding material layer 4. Although the shape and material of the heat exchange member 5 to be used differ depending on the application, when used as an air conditioning apparatus mainly for cooling, copper fins are preferable in terms of high thermal conductivity, and particularly used in air cooling. In this case, fins (for example, corrugated fins) manufactured in a wavy shape so as to increase the area in contact with air are desirable. Moreover, heat dissipation can be improved and the cooling characteristics can be improved by making the heat exchange member 5 on the heat radiation side have a larger heat exchange amount.

  Here, when attaching the heat exchange member 5 to the support substrate 1 with the bonding material layer 4, first, after applying the solder paste, it is attached by pressing from above and below, for example. By weakening only the part which becomes the outer peripheral side of the main surface, the thickness of the bonding material layer 4 at this part can be increased (a structure having a thick region 41).

  In particular, in order to make the thickness of the bonding material layer 4 gradually thinner from the thick region 41 toward the inside, the heat exchange member 5 is warped in advance and bonded while pressing only the central portion. This can be achieved.

  Further, when the heat exchange member 5 has a shape in which fins are erected on the base, it can be realized by, for example, extrusion molding. In addition, a plurality of bottom surface portions 51 in contact with the bonding material layer 4, a plurality of standing portions 52 respectively erected from the plurality of bottom surface portions 51, and a plurality of top surface portions 53 that connect adjacent standing portions 52 to each other For example, a corrugated fin is formed by pressing a thin copper plate and soldering it to form a corrugated fin. it can.

The bonding material layer 4 includes a plurality of regions provided independently of each other so as to correspond to the plurality of bottom surface portions 51, and the thick region 41 is located at the end in the meandering direction of the heat exchange member 5. The structure provided corresponding to the portion 51 can be realized by using solder as a material for forming the bonding material layer 4 and increasing the amount of application at the end with a dispenser or the like.

  Further, in order to obtain a configuration in which the thick region 41 is divided into a plurality of regions in a direction perpendicular to the meandering direction, solder is used as a material for forming the bonding material layer 4, and the solder is divided by screen printing. It can be realized by applying.

  Moreover, it can implement | achieve by making the edge part of the heat exchange member 5 shorter than a center part in order to make the some top surface part 53 in the heat exchange member 5 into the same plane.

  Moreover, in order to make the standing part located at the end of the heat exchange member 5 incline inward, the jig for joining the heat exchange member 5 and the support substrate 1 is inclined. realizable.

  Moreover, in order to make the structure in which the several top-surface part 53 in the heat exchange member 5 is covered with the case 6, it can implement | achieve by the structure which clamps a thermoelectric module with the resin-made cases 6, for example.

  Finally, a lead wire (not shown) for energizing the wiring conductor 2 is joined with a soldering iron and a laser or the like to obtain the thermoelectric module of the present invention.

  Hereinafter, the present invention will be described in more detail with reference to examples.

First, a P-type thermoelectric material and an N-type thermoelectric material made of Bi, Sb, Te, and Se were melted and solidified by the Bridgman method to produce a rod-shaped material having a circular cross section with a diameter of 1.5 mm. Specifically, the P-type thermoelectric material is made of a solid solution of Bi ₂ Te ₃ (bismuth telluride) and Sb ₂ Te ₃ (antimony telluride), and the N-type thermoelectric material is Bi ₂ Te ₃ (bismuth telluride). And Bi ₂ Se ₃ (bismuth selenide). Here, in order to roughen the surface, the surfaces of the rod-shaped P-type thermoelectric material and N-type thermoelectric material were etched with nitric acid.

  Next, an epoxy resin was applied to each of the rod-shaped P-type and N-type thermoelectric materials by dipping to form a coating layer on the side surface.

  Next, the rod-shaped P-type thermoelectric material and the rod-shaped N-type thermoelectric material coated with the coating layer are cut with a wire saw so as to have a height (thickness) of 1.6 mm, and the P-type thermoelectric element and N A mold thermoelectric element was obtained. The obtained P-type thermoelectric element and N-type thermoelectric element formed a nickel layer on the cut surface by electrolytic plating.

  Next, with respect to both main surface copper-clad substrates in which a copper plate having a thickness of 105 μm is pressed on both surfaces of an epoxy resin added with an alumina filler, one main surface is etched to form a wiring conductor having a desired wiring pattern (40 mm). Corner) was prepared. Then, 95Sn-5Sb solder paste is screen-printed on this wiring conductor, and 127 thermoelectric elements are arranged using a mounter so that the P-type thermoelectric element and the N-type thermoelectric element are electrically in series. Set up. The P-type thermoelectric element and the N-type thermoelectric element arranged as described above are sandwiched between two supporting substrates, heated in a reflow furnace while applying pressure to the upper and lower surfaces, and the wiring conductor and the thermoelectric element are soldered together. .

Next, using a metal mask, Sn-58Bi solder paste is screen-printed on the other main surface of the support substrate and disposed so as to be sandwiched between copper heat exchange members, and then pressure is applied to the upper and lower surfaces. The substrate was heated in a reflow furnace, and the support substrate and the heat exchange member were soldered. At this time, the pressure from the upper and lower surfaces is adjusted depending on the location, and the thickness of the bonding material layer located on the outer peripheral side (thermoelectric module peripheral portion) of the other main surface of the support substrate is shown in FIG. The thermoelectric module having the configuration of sample No. No. 1 (invention example), a thermoelectric module in which the entire area was pressurized with a uniform pressure and the bonding material layer had a uniform thickness was designated as Sample No. It produced as 2 (comparative example). Sample No. The thickness of the normal thickness region (thin region) in one bonding material layer was 50 μm, the thickness of the thick region was 100 μm, and the width (distance from the end) of the thick region was 500 μm. Sample No. The thickness of the bonding material layer 2 was 50 μm.

  Next, as an evaluation of the thermoelectric module manufactured under each condition, the cooling performance showing the thermoelectric characteristics was applied with Imax current (6A), and the temperature difference between the upper and lower heat exchange members was measured, and then at intervals of 3 minutes. An energization test for turning ON and OFF was performed for 20000 cycles.

  When the occurrence of cracks in the support substrate after this energization test was confirmed, Sample No. In the thermoelectric module of No. 2, there was a thermoelectric module in which the support substrate was cracked. In the thermoelectric module No. 1, no crack was generated in the support substrate.

  From this result, sample no. 1, the cooling performance does not deteriorate even after 20000 cycles, and the sample No. It can be seen that durability superior to 2 can be exhibited.

1, 1a, 1b Support substrate 2 Wiring conductor 3 Thermoelectric element 3a P-type thermoelectric element 3b N-type thermoelectric element 4 Bonding material layer 41 Thick region 5 Heat exchange member 51 Bottom surface portion 52 Standing portion 53 Top surface portion

Claims (8)

  A pair of support substrates arranged so as to face each other, a wiring conductor provided on one opposing main surface of the pair of supporting substrates, and the wiring conductor between one opposing main surfaces of the pair of supporting substrates A plurality of thermoelectric elements arranged so as to be electrically connected to each other, and a heat exchange member attached to the other main surface of at least one of the pair of support substrates via a bonding material layer. The thermoelectric module is characterized in that the bonding material layer has a thick region at a portion on the outer peripheral side of the other main surface.   The thermoelectric module according to claim 1, wherein the bonding material layer gradually decreases in thickness from the thick region toward the inside.   The heat exchange member includes a plurality of bottom surface portions in contact with the bonding material layer, a plurality of standing portions erected from the plurality of bottom surface portions, and a plurality of top surface portions that connect adjacent standing portions to each other. The thermoelectric module according to claim 1, wherein the plate-like body is bent so as to meander when viewed in cross section.   The bonding material layer is composed of a plurality of regions provided independently of each other so as to correspond to the plurality of bottom surface portions, and the thick region is located on a bottom surface portion located at an end in a meandering direction of the heat exchange member. The thermoelectric module according to claim 3, wherein the thermoelectric module is provided correspondingly.   The thermoelectric module according to claim 4, wherein the thick region is divided into a plurality of regions in a direction perpendicular to the meandering direction.   The thermoelectric module according to any one of claims 3 to 5, wherein the plurality of top surface portions of the heat exchange member are flush with each other.   The thermoelectric module according to any one of claims 3 to 6, wherein the standing portion located at an end of the heat exchange member is inclined inward.   The thermoelectric module according to any one of claims 1 to 7, wherein the plurality of top surface portions of the heat exchange member are covered with a case.