JP2020053572A - Manufacturing method of thermoelectric module, thermoelectric element, and thermoelectric module - Google Patents

Abstract

To provide a manufacturing method of a thermoelectric module that can easily arrange thermoelectric elements on an electrode and can reduce the number of steps.SOLUTION: After an upper substrate 11 on which an upper electrode 13 is formed is placed in a three-dimensional molding machine, and a P-type element 20p is formed on the upper electrode 13 to generate a first intermediate 23, a lower substrate 12 on which a lower electrode 14 is formed is placed in the three-dimensional molding machine, and an N-type element 20n is formed on the lower electrode 14 to generate a second intermediate 26. Thereafter, the first intermediate 23 and the second intermediate 26 face each other, the P-type element 20p of the first intermediate 23 is joined to the lower electrode 14 of the second intermediate 26, and the N-type element 20n of the second intermediate 26 is bonded to the upper electrode 13 of the first intermediate 23.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a method for manufacturing a thermoelectric module, a thermoelectric element, and a thermoelectric module.

  As a thermoelectric module (also referred to as a thermoelectric conversion module) utilizing the so-called Seebeck effect or Peltier effect, for example, a thermoelectric module disclosed in Patent Document 1 is known. This type of thermoelectric module is configured such that a plurality of thermoelectric elements (also referred to as thermoelectric conversion elements) are arranged between a pair of substrates on which electrode patterns are formed. In the thermoelectric module, a P-type element and an N-type element are used as the thermoelectric elements, and the electrode patterns of each substrate and each thermoelectric element are connected such that the thermoelectric elements having different polarities are electrically connected in series through the electrode patterns of each substrate. The arrangement pattern of the elements is determined.

  Here, a conventional method for manufacturing the thermoelectric module will be described. First, an ingot is prepared by sintering a powdery thermoelectric material, and this is cut into a predetermined thickness to prepare a plate. Thereafter, the plate is diced with a dicer or the like to form a plurality of thermoelectric elements having a predetermined shape (for example, prismatic shape). These steps are performed for each of the P-type thermoelectric element and the N-type thermoelectric element.

  After forming each of the P-type and N-type thermoelectric elements as described above, a solder cream or the like as a bonding material is applied on the electrode pattern formed on one substrate, and a plurality of thermoelectric elements are formed on the electrode pattern. Place them. At this time, the thermoelectric elements are arranged in a predetermined arrangement pattern so that the P-type element and the N-type element are connected in series. Thereafter, the other substrate having the bonding material applied on the electrode pattern is covered from above the one substrate on which the thermoelectric elements are arranged, such that the electrode forming surface is on the element side. Finally, it is introduced into a heating furnace such as a reflow furnace to perform a soldering process, thereby joining each thermoelectric element and the electrode pattern of each substrate.

JP-A-2006-147147

  In the conventional manufacturing method, it is necessary to arrange the thermoelectric elements one by one on the electrode pattern so that the thermoelectric elements are arranged in a predetermined arrangement pattern. However, such an operation is troublesome. For example, as the element size becomes smaller, it becomes more difficult to pinch the thermoelectric elements or to accurately arrange the thermoelectric elements according to the arrangement pattern.

  Further, in the conventional manufacturing method, the number of steps from the preparation of each thermoelectric element to the modularization increases, and there is a concern that the manufacturing cost increases and the productivity decreases.

  The present invention has been made in view of the above circumstances, and provides a method for manufacturing a thermoelectric module that can easily arrange thermoelectric elements on electrodes and reduce the number of steps. The purpose is to:

  Another object is to provide a thermoelectric element and a thermoelectric module that can be formed by such a manufacturing method.

  In order to solve the above problems, a first invention is a method for manufacturing a thermoelectric module, comprising: a first installation step of installing a first electrode inside a three-dimensional molding machine; A first forming step of forming a first thermoelectric element having one of the N-type and thermoelectric properties by the three-dimensional molding machine to generate a first intermediate; and forming a first thermoelectric element inside the three-dimensional molding machine. A second installation step of installing two electrodes, and forming, on the second electrode, a second thermoelectric element having the thermoelectric property of the other of the P-type and the N-type using the three-dimensional molding machine; (2) a second forming step of generating an intermediate; and joining the first thermoelectric element of the first intermediate to a second electrode of the second intermediate, and attaching the second thermoelectric element of the second intermediate to the second electrode. And a joining step of joining the first intermediate to the first electrode.

  According to the first aspect, the first thermoelectric element can be formed in a state where it is positioned on the first electrode, and the second thermoelectric element can be formed in a state where it is positioned on the second electrode. Therefore, it is not necessary to arrange each thermoelectric element on the electrode one by one after forming each thermoelectric element as in the related art, and it is possible to easily arrange the thermoelectric elements.

  In addition, since the formation of each thermoelectric element and the arrangement of each thermoelectric element with respect to each electrode are performed at the same time, it is possible to omit the element arrangement step conventionally performed separately from the element formation. In addition, in the three-dimensional molding machine, since the thermoelectric element can be formed directly from the powder of the thermoelectric material, a step of forming an ingot or a plate or dicing the plate can be omitted. Therefore, it is possible to reduce the total number of processes from creation of each thermoelectric element to modularization, and it is possible to reduce manufacturing costs and improve productivity.

  In the second aspect, in the first forming step, the first thermoelectric element is formed after the surface of the first electrode is softened by heating to near a melting point, or the second forming step is performed. Wherein the second thermoelectric element is formed after the surface of the second electrode is softened by heating to near the melting point.

  According to the second aspect, the thermoelectric element and the electrode can be joined in the first forming step or the second forming step, and the thermoelectric element fixed to the electrode can be formed. This suppresses a change in the posture and the position of the thermoelectric element when handling the first intermediate or the second intermediate, and makes it possible to manufacture the thermoelectric module in a state where the element arrangement is stabilized.

  In a third aspect, in the first aspect, a bonding material is attached to a surface of the first electrode before the first installation step, or the bonding material is attached to the surface of the first electrode before the second installation step. It is characterized in that a bonding material is attached to the surface of the two electrodes.

  According to the third aspect, in the first or second forming step, the thermoelectric element is formed with the bonding material interposed between the electrode and the electrode. Thereby, the first thermoelectric element and the first electrode can be joined, and the second thermoelectric element and the second electrode can be joined.

  In a fourth aspect, in any one of the first to third aspects, in the first forming step, the first thermoelectric element may be configured such that an area of a bonding surface on the first electrode side is the second electrode. Or in the second forming step, the second thermoelectric element is configured such that the area of the bonding surface on the first electrode side is the area of the bonding surface on the second electrode side. It is characterized in that it is formed larger.

  According to the fourth aspect, in the thermoelectric element, the temperature difference between the end on the first electrode side and the end on the second electrode side can be increased. As a result, the amount of power generated by the thermoelectric element can be increased, and a thermoelectric module having excellent thermoelectric efficiency can be manufactured.

  According to a fifth aspect of the present invention, there is provided a thermoelectric element in which a length direction is an electromotive force generation direction, and both ends of the electromotive force generation direction are bonding surfaces that are bonded to electrodes, wherein one of the two bonding surfaces is a bonding surface. The area of the surface is formed to be larger than the area of the other joining surface.

  According to the fifth aspect, the temperature difference between one end and the other end in the length direction (electromotive force generation direction) can be increased, and the amount of power generation can be increased.

  A sixth invention is characterized in that, in the fifth invention, it is formed in a truncated cone shape that is a truncated cone shape or a truncated pyramid shape.

  In the sixth aspect, the thermoelectric element according to the fifth aspect can be suitably realized by forming both end faces in the length direction (height direction) as the two joining surfaces according to the fifth aspect. Further, for example, the surface area of the side surface portion is larger than that of a columnar thermoelectric element having a constant cross-sectional area perpendicular to the length direction, and the heat radiation region on the side surface portion can be enlarged.

  According to a seventh aspect of the present invention, in the thermoelectric module, the thermoelectric element according to the fifth or sixth aspect is arranged such that a small-area side is a high-temperature side and a large-area side is a low-temperature side. , Characterized in that a plurality of thermoelectric elements are modularized.

  According to the seventh aspect, in each thermoelectric element, since the area of the bonding surface on the low temperature side is larger than the area of the bonding surface on the high temperature side, the amount of heat radiation on the low temperature side is larger than the amount of heat input on the high temperature side. be able to. For this reason, even if the temperature on the high-temperature end rises, the low-temperature end is easily maintained at a low temperature, and the temperature difference between these two ends can be suitably enlarged. As a result, the amount of power generated by each thermoelectric element can be increased, and a thermoelectric module having excellent thermoelectric efficiency can be realized.

The front view of the thermoelectric module concerning one embodiment of the present invention. FIG. 4 is a plan view of the upper substrate on which the upper electrode is formed, as viewed from the electrode side. FIG. 4 is a plan view of the lower substrate on which the lower electrode is formed, as viewed from the electrode side. Explanatory drawing for explaining the manufacturing method of a thermoelectric module. Explanatory drawing for explaining the manufacturing method of a thermoelectric module. The figure which shows the modification of a thermoelectric element.

  Hereinafter, an embodiment of the present invention will be described.

<Configuration of thermoelectric module>
The configuration of the thermoelectric module 10 according to the present invention will be described with reference to FIGS.

  As shown in FIG. 1, the thermoelectric module 10 includes a pair of upper and lower substrates 11 and 12 that are disposed to face each other, and a plurality of thermoelectric elements 20 that are disposed between the substrates 11 and 12.

  The upper substrate 11 is an insulating substrate, for example, a glass epoxy substrate or the like. As shown in FIG. 2, the upper substrate 11 has a rectangular shape in plan view, and a plurality of upper electrodes 13 as first electrodes are formed on the surface thereof. Each upper electrode 13 is formed of a conductive material such as copper, molybdenum, or an alloy thereof, and has a thin plate shape on which two thermoelectric elements 20 can be arranged.

  The lower substrate 12 is also an insulating substrate similarly to the upper substrate 11, and has a plurality of lower electrodes 14 as second electrodes formed on the surface thereof as shown in FIG. Each lower electrode 14 has the same shape and size as each upper electrode 13 of the upper substrate 11, but its arrangement position is shifted by a half pitch (one element) with respect to each upper electrode 13. It has become.

  Then, as shown in FIG. 1, the upper end 20 a of each thermoelectric element 20 is joined to the upper electrode 13 formed on the upper substrate 11, and each thermoelectric element 20 is connected to the lower electrode 14 formed on the lower substrate 12. Are joined at the lower end portion 20b. That is, in the present embodiment, the thermoelectric element 20 uses the length direction (the direction in which the electrodes 13 and 14 face each other) as the electromotive force generation direction, and more specifically, the upper end portion 20a and the lower end portion 20b. It is configured to generate an electromotive force by a temperature difference from the above. The thermoelectric element 20 is formed of a thermoelectric material such as a silicon-germanium-based, magnesium-silicide-based, or manganese-silicide-based.

  The thermoelectric module 10 has a P-type thermoelectric element (P-type element) 20p and an N-type thermoelectric element (N-type element) 20n as the thermoelectric elements 20, and these P-type element 20p and N-type element 20n The thermoelectric elements 20 are alternately arranged in the arrangement direction. One P-type element 20p and one adjacent N-type element 20n are paired, and the upper ends of both elements 20p and 20n are joined to one upper electrode 13. At this time, since the arrangement positions of the upper electrode 13 and the lower electrode 14 are shifted by a half pitch, on the lower substrate 12 side, the N-type element 20n joined to one of the adjacent upper electrodes 13a and 13b and the other Each lower end of the P-type element 20p joined to the lower electrode 14 is joined to one lower electrode 14.

  Note that, in FIG. 2, respective joining surfaces of the P-type element 20p and the N-type element 20n with respect to the upper electrode 13 are denoted by reference numerals 21p and 21n, respectively, and in FIG. Each joining surface is indicated by reference numerals 22p and 22n. In these figures, different hatchings are attached to the junction surfaces 21p and 22p of the P-type element 20p and the junction surfaces 21n and 22n of the N-type element 20n in order to facilitate the distinction.

  By joining the P-type element 20p and the N-type element 20n to the upper electrode 13 and the lower electrode 14 as described above, the two elements 20p and 20n are electrically connected in series, and A route is configured. Lead wires 15 are drawn out from the lower electrodes 14a and 14b which are both ends of the series path, and it is possible to take out electric power generated in the thermoelectric module 10 via the lead wires 15.

  When using the thermoelectric module 10, the thermoelectric module 10 is arranged between a heat source such as a heating duct and a cooling device such as a cooling duct. Thereby, a temperature difference is given to the thermoelectric module 10, and each thermoelectric element 20 generates electric power. At this time, in the present embodiment, the orientation of the thermoelectric module 10 is set such that the upper substrate 11 is on the cooling device side and the lower substrate 12 is on the heat source side. That is, a temperature difference is provided so that the upper substrate 11 side has a low temperature and the lower substrate 12 side has a high temperature. It is not always necessary to use both the heat source and the cooling device, and only one of them may be used.

  Here, in the present embodiment, the shape of the thermoelectric element 20 is devised to increase the amount of power generation. Hereinafter, such a configuration will be described.

  As shown in FIGS. 2 and 3, thermoelectric element 20 according to the present embodiment is formed such that the area of bonding surface 21 to upper electrode 13 is larger than the area of bonding surface 22 to lower electrode 14. . More specifically, as shown in FIG. 1, the thermoelectric element 20 has a truncated pyramid shape, and is configured such that both end surfaces in the length direction (height direction) are the two bonding surfaces 21 and 22.

  In such a configuration, when the lower substrate 12 is a high-temperature substrate and the upper substrate 11 is a low-temperature substrate, the upper surface 20a of each thermoelectric element 20 has a large area of the bonding surface 21 located on the low-temperature side. The amount of heat dissipation on the side also increases. In this case, even if the lower end portion 20b side is heated by the heat from the lower substrate 12, the upper end portion 20a side is easily maintained at a low temperature, and the temperature difference between the upper end portion 20a and the lower end portion 20b can be increased. Accordingly, the amount of power generated by each thermoelectric element 20 is increased, and the thermoelectric efficiency of the thermoelectric module 10 can be improved.

  Further, since each of the thermoelectric elements 20 has a truncated pyramid shape, the surface area of the side surface portion 20c is larger than in the case of, for example, a prismatic shape, and the heat radiation region is also enlarged in the side surface portion 20c. This suppresses transmission of heat from the lower substrate 12 to the upper end portion 20a of the thermoelectric element 20, and can further increase the temperature difference between the upper end portion 20a and the lower end portion 20b.

<Method of Manufacturing Thermoelectric Module 10>
In the present embodiment, the thermoelectric module 10 is manufactured using a three-dimensional molding machine. Hereinafter, a specific method thereof will be described in detail with reference to FIGS.

  In manufacturing the thermoelectric module 10, first, as shown in FIG. 4A, the upper substrate 11 on which the upper electrode 13 is formed is set on a setting table 31 in a three-dimensional molding machine (first setting step). At this time, the upper substrate 11 is positioned at a predetermined installation position on the installation table 31 with the formation surface of the upper electrode 13 facing upward.

  Next, as shown in FIG. 4B, each P-type element 20p is formed on each electrode 13 of the upper substrate 11 placed on the placement table 31 by a three-dimensional molding machine, and the first intermediate body 23 is formed. Generated (first forming step). In this step, first, a thermoelectric material powder constituting the P-type element 20p is spread over the entire surface of the upper substrate 11 on which the upper electrode 13 is formed to form a thermoelectric material layer (powder bed) 24. Thereafter, a laser beam is applied to a region 25 of the thermoelectric material layer 24 where the P-type element 20p is to be formed, and the thermoelectric material layer 24 in the region 25 is melted and sintered. This is repeated by the height of the P-type element 20p, and the sintered portions are stacked. At that time, since the upper layer is also bonded to the lower sintered portion (lamination in the laminating direction) at the time of laser irradiation, the integrated P-type element 20p is formed.

  In the three-dimensional molding machine, three-dimensional data indicating the shape, various sizes, and arrangement patterns (coordinate positions) of each P-type element 20p is input or stored, and the laser beam irradiation processing is performed based on the three-dimensional data. Is performed. Therefore, in the first forming step, not only are all the P-type elements 20p arranged on the upper substrate 11 formed in parallel, but also each P-type element 20p is positioned at a position corresponding to the array pattern. It is formed in a state. That is, formation and arrangement of each P-type element 20p are performed simultaneously.

  When forming each P-type element 20p, each time one thermoelectric material layer 24 is formed on the upper substrate 11, the material layer 24 is irradiated with a laser beam for sintering. In this case, at the time of laser irradiation performed at the time of forming the first layer, a part of the laser light is transmitted through the thermoelectric material layer 24 or the heat of the thermoelectric material layer 24 is transmitted to the upper electrode 13 so that the upper electrode 13 Surface temperature rises.

  At that time, the surface of the upper electrode 13 is heated to near the melting point and softened by adjusting the output and irradiation time of the laser beam. Thereby, in the region 25 irradiated with the laser beam, the upper electrode 13 in the softened state and the thermoelectric material layer 24 in the molten state are adapted to each other, and thereafter, the two are solidified and joined. That is, in the present embodiment, the joining between the upper electrode 13 and the P-type element 20p is also performed in the first forming step, not limited to the formation and arrangement of the P-type element 20p.

  For example, if the thermoelectric elements are not joined at the stage of disposing the thermoelectric elements on the electrodes as in the above-described conventional manufacturing method, the element arrangement is likely to be disturbed when transported to a reflow furnace or the like. For this reason, there is a possibility that a careful transport operation is required, and the element arrangement needs to be redone or corrected. Also, in a heating step using a reflow furnace or the like, there is a concern that the element may tilt or move when the solder at both ends of the element is melted.

  In this regard, in the present embodiment, since the bonding with the upper electrode 13 is performed together with the formation of each P-type element 20p, the posture and position of the P-type element 20p can be fixed, and the element is formed in a subsequent step. Arrangement can be suppressed. As a result, not only the transportation becomes easy, but also the occurrence of redoing of the element arrangement can be suppressed, and the productivity can be improved.

  The particle size of the powder of the thermoelectric material is not particularly limited, but is preferably 1 μm or more and 100 μm or less, more preferably 10 μm or more and 80 μm or less. By setting the particle diameter of the powder to 1 μm or more, the thickness dimension of one layer in the thermoelectric material layer 24 does not become too small, and the molding time of the P-type element 20p can be prevented from becoming excessively long. By setting the particle diameter of the powder to 100 μm or less, the thickness is prevented from being excessively large, the P-type element 20p having a smooth side surface can be easily formed, and the upper electrode 13 is heated during laser irradiation. This facilitates the joining process.

  After the first intermediate body 23 is formed as described above, the first intermediate body 23 is taken out from the three-dimensional molding machine, and then, as shown in FIG. 31 (second installation step). At this time, the lower substrate 12 is positioned at a predetermined installation position on the installation table 31 with the formation surface of the lower electrode 14 facing upward.

  Next, as shown in FIG. 4D, each N-type element 20n is formed on each electrode 14 of the lower substrate 12 set on the setting table 31 by a three-dimensional molding machine, and the second intermediate body 26 is formed. Generated (second forming step). This second forming step is performed in the same manner as in the first forming step, using a powder of a thermoelectric material constituting the N-type element 20n. After the completion of the second forming step, the second intermediate body 26 is removed from the three-dimensional molding machine.

  Thereafter, a bonding material 27 (see FIG. 5) such as solder cream is applied to each of the upper electrode 13 of the first intermediate body 23 and the lower electrode 14 of the second intermediate body 26. The bonding material 27 is applied to portions of the surfaces of the upper electrode 13 and the lower electrode 14 where the P-type element 20p and the N-type element 20n are not formed.

  Subsequently, as shown in FIG. 5, the first intermediate body 23 on which the bonding material 27 is applied is turned upside down to be opposed to the second intermediate body 26 on which the bonding material 27 is applied. Then, after the first intermediate body 23 and the second intermediate body 26 are aligned, the first intermediate body 23 is moved toward the second intermediate body 26. Thereafter, the P-type element 20p formed on the first intermediate body 23 contacts the lower electrode 14 (bonding material 27) of the second intermediate body 26, and the N-type element 20n formed on the second intermediate body 26 The two intermediates 23 and 26 are brought close to each other until they come into contact with the upper electrode 13 (joining material 27) of the first intermediate 23, thereby generating a third intermediate. This operation may be performed manually, or may be performed mechanically using a lifting device or the like.

  Finally, the third intermediate is introduced into a heating furnace such as a reflow furnace and subjected to heat treatment. Thereby, the P-type element 20p of the first intermediate body 23 is joined to the lower electrode 14 of the second intermediate body 26, and the N-type element 20n of the second intermediate body 26 is joined to the upper electrode 13 of the first intermediate body 23. (Joining step). When a solder cream is used as the joining material 27, the joining process is a soldering process, and the heating process is a soldering process.

  According to the present embodiment described in detail above, the following excellent effects can be obtained.

  -The upper substrate 11 on which the upper electrode 13 is formed is placed inside a three-dimensional molding machine, and the P-type element 20p is formed on the upper electrode 13 to generate the first intermediate 23, and then the lower electrode 14 is formed. The completed lower substrate 12 was placed inside a three-dimensional molding machine, and an N-type element 20 n was molded on the lower electrode 14 to produce a second intermediate 26. Thereafter, the first intermediate body 23 and the second intermediate body 26 are opposed to each other, the P-type element 20p of the first intermediate body 23 is joined to the lower electrode 14 of the second intermediate body 26, and the N-type element of the second intermediate body 26 is formed. 20n was bonded to the upper electrode 13 of the first intermediate body 23.

  According to the above configuration, the P-type element 20p can be formed with the upper electrode 13 positioned, and the N-type element 20n can be formed with the lower electrode 14 positioned. Therefore, it is not necessary to arrange each thermoelectric element on the electrode one by one after forming each thermoelectric element as in the related art, and it is possible to easily arrange the thermoelectric elements.

  In addition, since the formation of each thermoelectric element 20 and the arrangement of each thermoelectric element 20 with respect to each of the electrodes 13 and 14 are performed at the same time, it is possible to omit the element arrangement step conventionally performed separately from element formation. In addition, since the thermoelectric element 20 can be formed directly from the powder of the thermoelectric material, the steps of creating an ingot or a plate or dicing the plate can be omitted. Therefore, it is possible to reduce the total number of processes from creation of each thermoelectric element to modularization, and it is possible to reduce manufacturing costs and improve productivity.

  -After the surface of the upper electrode 13 was softened by heating to near the melting point, the P-type element 20p was formed. In this case, the P-type element 20p and the upper electrode 13 can be joined in the first forming step, and the P-type element 20p fixed to the upper electrode 13 can be formed. This suppresses a change in the posture or position of the P-type element 20p when the first intermediate body 23 is taken out or carried, and the handling of the first intermediate body 23 is facilitated. Further, even when the bonding material 27 on the lower electrode 14 is melted in the bonding step, the P-type element 20p does not tilt or move.

  Also, in the second forming step, since the surface of the lower electrode 14 is softened by heating to near the melting point and then the N-type element 20n is formed, the same effect as described above can be obtained in the second intermediate body 26. It is possible to obtain. In the above embodiment, the thermoelectric element is formed after the electrode surface is softened in both the first and second forming steps. However, the thermoelectric element may be formed only in one of the steps.

  The thermoelectric element 20 was configured so that the area of the bonding surface 21 with respect to the upper electrode 13 was larger than the area of the bonding surface 22 with respect to the lower electrode 14. In this case, the difference between the amount of heat input on the high-temperature side and the amount of heat radiation on the low-temperature side of the thermoelectric element 20 can be increased, and the temperature difference between the upper end portion 20a and the lower end portion 20b can be increased. In particular, in the case where the lower substrate 12 is a high-temperature substrate and the upper substrate 11 is a low-temperature substrate, even if the lower end portion 20b is heated by the heat from the lower substrate 12, the upper end portion 20a is maintained at a low temperature. The temperature difference between the two end portions 20a and 20b can be suitably enlarged.

<Other embodiments>
The present invention is not limited to the above embodiment, and may be implemented, for example, as follows.

  (1) In the above-described embodiment, the thermoelectric module 10 is configured to generate power by giving a temperature difference. However, each thermoelectric element 20 is used as a Peltier element, and a current is caused to flow through each thermoelectric element 20 to generate a temperature difference. It may constitute a temperature control device (for example, a cooling device).

  (2) In the above embodiment, each thermoelectric element 20 is formed by a powder sintering method in a three-dimensional molding machine. However, for example, each thermoelectric element 20 is formed by another three-dimensional molding method such as a sheet lamination method or a directional energy deposition method. The element 20 may be formed.

  (3) In the above embodiment, the substrate on which the electrodes are formed is installed inside the three-dimensional molding machine. However, the configuration may be such that the electrodes not formed on the substrate are installed. However, in this case, since the individual electrodes are in a separated state, there is a concern that installation in a three-dimensional molding machine or the like takes time, and from such a viewpoint, it is preferable to configure as in the above embodiment.

  (4) In the above embodiment, the surface of the upper electrode 13 is softened to join the P-type element 20p. However, depending on the combination of the constituent material of the upper electrode 13 and the constituent material of the P-type element 20p. May be difficult to join the two. In such a case, a bonding material such as solder cream is applied on the upper electrode 13 before the first installation step, and the upper substrate 11 to which the bonding material is applied is three-dimensionally formed in the first installation step. You may make it install in a plane. In this case, the thermoelectric element 20 is formed on the bonding material in the first forming step, and the upper electrode 13 and the P-type element 20p can be bonded by the bonding material.

  In addition, by using the same bonding material as the bonding material used for bonding the lower electrode 14 and the P-type element 20p, the bonding between the upper electrode 13 and the P-type element 20p and the lower electrode 14 And the joining of the P-type element 20p can be performed together, and the manufacturing process can be simplified. The installation of the substrate with the bonding material on the electrodes can also be performed in the second installation step. However, it is not always necessary to perform both in the first installation step and the second installation step, and it may be performed in only one of them.

  (5) In the above embodiment, after the first forming step, a bonding material such as a solder cream may be applied around a bonding portion between the upper electrode 13 and the P-type element 20p. For example, when the holding force of the P-type element 20p by the softening bonding is insufficient, it can be supported by the viscosity of the bonding material. Further, when the bonding material applied to the periphery of the bonding portion is solidified in a subsequent bonding step, it contributes to bonding between the upper electrode 13 and the P-type element 20p. It is also possible to enhance the bonding strength of 20p. The joining material does not necessarily need to be applied to the entire periphery of the joint, but may be applied to at least a part. In addition, the above configuration can be applied to the relationship between the lower electrode 14 and the N-type element 20n, but in that case, it may be performed only with either the P-type element 20p or the N-type element 20n.

  (6) In the above embodiment, prior to the first installation step, the difference between the thermoelectric material layer 24 and the thermoelectric material layer 24 in reflectance with respect to laser light (laser light whose wavelength is set according to the thermoelectric material) is larger than that of the upper electrode 13. A small conductive material layer may be formed on the surface of the upper electrode 13. That is, the upper electrode 13 includes a second conductive layer and a first conductive layer provided on the second conductive layer and having a difference in reflectance from the thermoelectric material layer 24 smaller than the second conductive layer, The P-type element 20p may be formed on the first conductive layer. When the reflectivity of the thermoelectric material layer 24 and the reflectivity of the upper electrode 13 for laser light are significantly different, it may be difficult to join the two by laser irradiation. By performing the above, it can be expected that the joining is facilitated.

  When the upper electrode 13 (second conductive layer) is made of copper, the first conductive layer may be formed by, for example, performing nickel plating on the electrode 13. In addition, the above configuration can be applied to the lower electrode 14, but in that case, it may be performed with only the upper electrode 13 or the lower electrode 14.

  (7) In the above embodiment, the bonding material is applied to each of the upper electrode 13 of the first intermediate body 23 and the lower electrode 14 of the second intermediate body 26. A bonding material may be applied to the bonding surface 22p of the P-type element 20p in the first intermediate body 23 and not to the second intermediate body 26 side. In this case, since the coating operation only needs to be performed on one of the intermediates, the process can be simplified. In addition, contrary to the above, the application operation may be performed on the second intermediate body 26.

  (8) In the above embodiment, the thermoelectric element 20 has a truncated pyramid shape, but may have a truncated cone shape. Further, as shown in FIG. 6A, a groove 33 may be formed on the side surface portion 20c of the thermoelectric element 20 to provide unevenness, or the side surface portion 20c may be formed as a curved surface. Thereby, the heat dissipation effect can be enhanced by increasing the surface area of the side surface portion 20c, and the temperature difference between the both end portions 20a, 20b can be further increased.

  Note that the unevenness and the curved surface are not alternatives, and may be used in combination. Also, these need not necessarily be formed on the entire side surface portion 20c, but may be formed on a part thereof. Further, the groove 33 is not limited to a spiral groove, and may have another groove shape such as a vertical groove. Incidentally, the above-mentioned modified example employing the irregularities and the curved surface is included in the “frustum shape” of the present invention. That is, the “frustum shape” of the present invention is not limited to a perfect frustum shape, but is a concept that includes a generally frustum shape as a whole.

  Further, as shown in FIG. 6B, a configuration may be adopted in which a hollow portion 34 is provided inside the thermoelectric element 20 and a heat radiation surface (heat radiation portion) is secured inside the element.

  DESCRIPTION OF SYMBOLS 10 ... thermoelectric module, 13 ... upper electrode, 14 ... lower electrode, 20 ... thermoelectric element, 20p ... P-type element, 20n ... N-type element, 21 ... joint surface, 22 ... joint surface, 23 ... 1st intermediate body, 26 ... Second intermediate.

Claims (7)

A first installation step of installing a first electrode inside the three-dimensional molding machine;
A first forming step of forming a first thermoelectric element having one of P-type and N-type thermoelectric characteristics on the first electrode by the three-dimensional molding machine to generate a first intermediate; ,
A second installation step of installing a second electrode inside the three-dimensional molding machine;
A second forming step of forming a second thermoelectric element having the thermoelectric property of the other of the P type and the N type on the second electrode by the three-dimensional molding machine to generate a second intermediate; and ,
The first thermoelectric element of the first intermediate is joined to the second electrode of the second intermediate, and the second thermoelectric element of the second intermediate is joined to the first electrode of the first intermediate. Joining process,
A method for manufacturing a thermoelectric module, comprising: In the first forming step, the first thermoelectric element is formed after the surface of the first electrode is softened by heating to near a melting point.
Alternatively, in the second forming step, the second thermoelectric element is formed after the surface of the second electrode is softened by heating to near a melting point.
A method for manufacturing the thermoelectric module according to claim 1. Before the first installation step, a bonding material is attached to a surface of the first electrode,
Alternatively, a bonding material is attached to the surface of the second electrode before the second installation step.
A method for manufacturing the thermoelectric module according to claim 1. In the first forming step, the first thermoelectric element is formed such that an area of a bonding surface on the first electrode side is larger than an area of a bonding surface on the second electrode side.
Alternatively, in the second forming step, the second thermoelectric element is formed such that an area of a bonding surface on the first electrode side is larger than an area of a bonding surface on the second electrode side.
A method for manufacturing the thermoelectric module according to claim 1. A thermoelectric element in which a length direction is an electromotive force generation direction, and both ends of the electromotive force generation direction are bonding surfaces that are bonded to electrodes.
A thermoelectric element, wherein an area of one of the two bonding surfaces is larger than an area of the other bonding surface.   The thermoelectric element according to claim 5, wherein the thermoelectric element is formed in a truncated cone shape that is a truncated cone shape or a truncated pyramid shape.   7. The thermoelectric element according to claim 5, wherein the thermoelectric element according to claim 5 or 6 is arranged such that a large-area side is a low-temperature side and a small-area side is a high-temperature side, and a plurality of thermoelectric elements are modularized. module.

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