JP2017143101A - Thermoelectric conversion module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the reliability of a thermoelectric conversion module.SOLUTION: A thermoelectric conversion module 100 comprises a plurality of electrically connected thermoelectric conversion elements (P-type thermoelectric conversion element 3 and an N-type thermoelectric conversion element 13) of P- and N-type semiconductors. Each of the plurality of thermoelectric conversion elements is connected by an electrode, and the plurality of thermoelectric conversion elements are connected in series. Furthermore, the plurality of P- or N-type thermoelectric conversion elements of P- and N-type semiconductors are connected in parallel to some of the thermoelectric conversion elements located in an outer peripheral part (peripheral edge part) or a corner part of the thermoelectric conversion module 100. The sum of connection areas of the plurality of parallely connected thermoelectric conversion elements and the electrode is not less than the connection area of one thermoelectric conversion element arranged in other than the outer peripheral part (peripheral edge part) or the corner part and the electrode.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a thermoelectric conversion module that converts heat into electricity.

  As a module technology for converting heat into electricity, there is JP 2002-111080 (Patent Document 1). This publication states that “the area of the bonding electrode where two thermoelectric elements having the same characteristics are bonded is larger than the area of the bonding electrode where only one thermoelectric element having the same characteristics is bonded. In the corner portion of the array pattern where the thermal stress is concentrated and the folded portion of the circuit pattern, the load can be shared by the two thermoelectric elements, and the bonding area between the bonding electrode and the thermoelectric element is increased. ” Have been described.

JP 2002-111108 A

  In recent years, thermoelectric conversion modules that are attached to piping of industrial furnaces such as blast furnaces and incinerators or exhaust pipes of automobiles and utilize the waste heat temperature have been developed. The target waste heat temperature is a high temperature of about 200 to 900 ° C., and in order to maximize the performance of the thermoelectric conversion module, it is necessary to efficiently transfer the heat of the heat source body to the thermoelectric conversion module.

  Since the thermoelectric conversion module converts the temperature difference between the front and back surfaces of the thermoelectric conversion element included in the module into electricity, stress is generated in the thermoelectric conversion element due to the difference in linear expansion coefficient between the thermoelectric conversion element and the electrode.

  Further, when the module size is increased, the stress on the thermoelectric conversion element in the vicinity of the outer peripheral portion of the module increases due to the thermal expansion of the entire module, and the possibility of element breakage increases. For this reason, in order to improve the reliability of the thermoelectric conversion module, it is important to prevent disconnection of the outer periphery of the module where stress is likely to occur.

  The objective of this invention is providing the technique which improves the reliability of a thermoelectric conversion module.

  The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

  Of the inventions disclosed in this application, the outline of typical ones will be briefly described as follows.

  A thermoelectric conversion module according to the present invention includes an insulating substrate on which an electrode is disposed, a P-type thermoelectric element disposed on the insulating substrate, and an N-type thermoelectric element disposed on the insulating substrate. A plurality of thermoelectric elements of either the P type or the N type are connected to the electrode, and the other thermoelectric element of the P type or the N type is connected to the electrode.

  Furthermore, the sum total of the connection areas of the one thermoelectric element connected to the electrode is equal to or greater than the connection area of the other thermoelectric element to the electrode.

  Of the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

  The reliability of the thermoelectric conversion module can be improved.

It is a perspective view which shows an example of the structure of the thermoelectric conversion module by Embodiment 1 of this invention. FIG. 2 is a plan transmission diagram illustrating an example of an element layout of the thermoelectric conversion module illustrated in FIG. 1. It is a side view which shows an example of the element junction part structure in the corner part vicinity of the thermoelectric conversion module shown in FIG. It is a plane | planar permeation | transmission figure which shows the element layout of the thermoelectric conversion module of the modification of Embodiment 1 of this invention. It is a plane transmission figure which shows an example of the element layout of the thermoelectric conversion module by Embodiment 2 of this invention. It is a side view which shows an example of the element junction part structure in the corner part vicinity of the thermoelectric conversion module shown in FIG. It is a side view which shows an example of the element junction part structure in the corner part vicinity of the thermoelectric conversion module by Embodiment 3 of this invention. It is a plane | planar transparent figure which shows the element layout of the thermoelectric conversion module of the modification of Embodiment 3 of this invention.

  In the following embodiments, when necessary for the sake of convenience, the description will be divided into a plurality of sections or embodiments. However, unless otherwise specified, they are not irrelevant to each other, and one is the other. There are some or all of the modifications, details, supplementary explanations, and the like.

  Further, in the following embodiments, when referring to the number of elements (including the number, numerical value, quantity, range, etc.), especially when clearly indicated and when clearly limited to a specific number in principle, etc. Except, it is not limited to the specific number, and may be more or less than the specific number.

  Further, in the following embodiments, the constituent elements (including element steps) are not necessarily indispensable unless otherwise specified and clearly considered essential in principle. Needless to say.

  In addition, when referring to “consisting of A”, “consisting of A”, “having A”, and “including A”, other elements are excluded unless specifically indicated that only that element is included. It goes without saying that it is not what you do. Similarly, in the following embodiments, when referring to the shapes, positional relationships, etc. of the components, etc., the shapes are substantially the same unless otherwise specified, or otherwise apparent in principle. And the like are included. The same applies to the above numerical values and ranges.

  Further, in the drawings used in the following embodiments, hatching may be added to make the drawings easy to see even if they are plan views. In all the drawings for explaining the following embodiments, components having the same function are denoted by the same reference numerals in principle, and repeated description thereof is omitted. Hereinafter, the present embodiment will be described in detail with reference to the drawings.

(Embodiment 1)
1 is a perspective view showing an example of the structure of a thermoelectric conversion module according to Embodiment 1 of the present invention, FIG. 2 is a plan transparent view showing an example of an element layout of the thermoelectric conversion module shown in FIG. 1, and FIG. 4 is a side view showing an example of an element joint structure in the vicinity of a corner portion of the thermoelectric conversion module shown, and FIG. 4 is a plan transparent view showing an element layout of a thermoelectric conversion module according to a modification of the first embodiment of the present invention.

  A thermoelectric conversion module 100 according to the first embodiment shown in FIG. 1 includes a thermoelectric conversion element (hereinafter referred to as a P-type thermoelectric conversion element) 3 made of a P-type semiconductor and a thermoelectric conversion element (hereinafter referred to as an N-type) made of an N-type semiconductor. The Seebeck effect is used, in which electrons move by generating a temperature difference between the upper and lower surfaces of each of the four) (referred to as thermoelectric conversion elements). The thermoelectric conversion module 100 has a function of converting heat into electricity by the movement of the electrons. Hereinafter, the thermoelectric conversion element is also simply referred to as a thermoelectric element.

  An electrical circuit is formed by alternately connecting the P-type thermoelectric conversion elements 3 and the N-type thermoelectric conversion elements 4. The thermoelectric conversion module 100 is configured by arranging the P-type thermoelectric conversion element 3 and the N-type thermoelectric conversion element 4 thus connected in a planar shape (lattice shape), a line shape, a cylindrical shape, or the like.

  Furthermore, the structure of the thermoelectric conversion module 100 is demonstrated in detail using FIG.1, FIG.2 and FIG.3. FIG. 1 is a perspective view of the thermoelectric conversion module 100 when the upper surface is at a high temperature and the lower surface is at a low temperature. The thermoelectric conversion module 100 includes an insulating substrate 6 on which a plurality of electrodes are disposed, a plurality of P-type thermoelectric conversion elements 3 disposed on the insulating substrate 6, and a plurality of N-type thermoelectric conversions disposed on the insulating substrate 6. And an element 4. Furthermore, any one of the P-type thermoelectric conversion element 3 or the N-type thermoelectric conversion element 4 is connected to any of the plurality of electrodes, and the P-type thermoelectric conversion element 3 or the N-type thermoelectric conversion is connected. The other thermoelectric element of the elements 4 is connected.

  Each P-type thermoelectric conversion element 3 is connected to the N-type thermoelectric conversion element 4 by a high temperature side electrode 1 and a low temperature side electrode 2. For simplification, FIG. 1 does not show bonding materials for the P-type thermoelectric conversion element 3 and the N-type thermoelectric conversion element 4 and the high-temperature side electrode 1 and the low-temperature side electrode 2. The low temperature side electrode 2 is connected to the insulating substrate 6. That is, a plurality of low temperature side electrodes 2 are arranged on the element arrangement surface (upper surface) 6 a of the insulating substrate 6. And the magnitude | size of each planar view of the some electrode (low temperature side electrode 2) is the same.

  The electricity generated by the temperature difference between the high temperature side and the low temperature side is taken out by the lead wiring 5. As shown in FIG. 1, a plurality of P-type thermoelectric conversion elements 3 and N-type thermoelectric conversion elements 4 in the corner (corner) at the periphery of the element arrangement surface (upper surface) 6 a of the insulating substrate 6 are arranged in parallel. Connected with.

  FIG. 2 is a plan transparent view showing an element layout of the thermoelectric conversion module 100, and is a view through which the high temperature side electrode 1 is transmitted when the thermoelectric conversion module 100 of FIG. 1 is viewed from the high temperature side electrode 1 side. FIG. 3 is a side view showing the vicinity of the corner of the element joint structure of the thermoelectric conversion module 100. The left end of FIG. 3 is a corner portion. As shown in FIG. 3, the corner portion thermoelectric conversion element 12 disposed in the corner portion is connected to the high temperature side electrode 10 with the high temperature side bonding material 11 sandwiched between the high temperature side upper surface and the low temperature side lower surface. The low temperature side electrode 14 is connected with the low temperature side bonding material 15 in between. The low temperature side electrode 14 is further connected to a low temperature side insulating plate (insulating substrate 6) 16.

  Thus, as shown in FIG. 1, the high temperature side electrode 1 disposed across the upper surface of the P-type thermoelectric conversion element 3 and the upper surface of the N-type thermoelectric conversion element 4, and the lower surface of the P-type thermoelectric conversion element 3 Adjacent P-type thermoelectric conversion elements 3 and N-type thermoelectric conversion elements 4 are connected in series alternately by the low temperature side electrode 2 arranged over the lower surface of the N-type thermoelectric conversion element 4. That is, the P-type thermoelectric conversion element 3 and the N-type thermoelectric conversion element 4 are connected in series using the high temperature side electrode 1 and the low temperature side electrode 2 as an electrical conduction path. In other words, the plurality of P-type thermoelectric conversion elements 3 and the plurality of N-type thermoelectric conversion elements 4 are alternately connected in series like a single stroke (continuous).

  And in the thermoelectric conversion module 100 of this Embodiment 1, the thermoelectric conversion element arrange | positioned at the corner part (corner | corner part) of the element arrangement surface 6a of the insulating substrate 6 has a plurality of cases both in the P type and the N type. Elements are arranged in parallel. Further, as shown in FIG. 2, the connection area of each element, that is, the connection area between the high temperature side electrode 1 and the corner portion thermoelectric conversion element, and the connection area between the low temperature side electrode 2 and the corner portion thermoelectric conversion element. Is smaller than the connection area between the thermoelectric conversion element other than the corner portion and the high temperature side electrode 1 and between the thermoelectric conversion element other than the corner portion and the low temperature side electrode 2. On the other hand, the sum total of the connection areas of the plurality of corner part thermoelectric conversion elements is the connection area between the thermoelectric conversion elements other than the corner part and the high temperature side electrode 1 and the connection between the thermoelectric conversion elements other than the corner part and the low temperature side electrode 2. Greater than area.

  That is, the sum of the connection areas between the electrodes of any one of the P-type and N-type thermoelectric elements connected at the corner (corner) where the stress of the insulating substrate 6 tends to concentrate is P-type and N-type. It is larger than the connection area with the electrode of one of the other thermoelectric elements.

  Note that, as in the structure of FIG. 5 described later, the sum of the connection areas between the electrodes of any one of the P-type and N-type connected thermoelectric elements is either P-type or N-type. It may be the same as the connection area with the electrode of the other one thermoelectric element.

  In other words, the sum of the connection areas of the electrodes of either one of the P-type and N-type thermoelectric elements connected at the corner is the sum of the other one of the P-type and N-type thermoelectric elements. It may be equal to or larger than the connection area with the electrode.

  Note that the position (location) where a plurality of thermoelectric elements of any one of the P-type and N-type are arranged is not limited to the corner (corner) of the insulating substrate 6, and is a modification of FIG. As shown in FIG. 4, the outer peripheral portion (peripheral portion, for example, E portion or F portion) of the element arrangement surface 6a of the insulating substrate 6 where stress is likely to concentrate may be used as in the corner portion (corner portion).

  Here, the definition of the outer peripheral portion (peripheral portion) of the insulating substrate 6 on which a plurality of either one of the P-type and N-type thermoelectric elements are arranged will be described. The outer peripheral portion (peripheral portion) of the insulating substrate 6 is, for example, an outermost row and a region from the outer side to the second row along the peripheral portion of the plurality of thermoelectric elements arranged on the insulating substrate 6. .

  Alternatively, the outer peripheral portion (peripheral portion) of the insulating substrate 6 is, for example, the outermost row along the peripheral portion in the arrangement of a plurality of electrodes (low temperature side electrodes 14) arranged on the insulating substrate 6 and This is the area from the outside to the second row. By disposing any one of the P-type and N-type thermoelectric elements in these regions, the stress applied to the outer peripheral portion of the insulating substrate 6 can be dispersed.

  And, in another expression, the characteristics of the thermoelectric conversion module 100 of the first embodiment will be described. Each of the thermoelectric elements connected in parallel at the corner portion or the outer peripheral portion (peripheral portion) of the insulating substrate 6. The connection area with the electrode is smaller than the connection area with the electrode of the thermoelectric element connected in series at a place other than the corner part or the outer peripheral part (peripheral part).

  Furthermore, the sum total of the connection areas with the respective electrodes of the plurality of thermoelectric elements connected in parallel at the corner portion or the outer peripheral portion (peripheral portion) of the insulating substrate 6 is a place other than the corner portion or the outer peripheral portion (peripheral portion). It is more than the connection area with the electrode of the thermoelectric element connected in series.

  Further, using another expression, one of the P-type or N-type thermoelectric elements connected (for example, the P-type corner portion thermoelectric conversion element 12 in FIG. 2) is In the arrangement, as shown in FIG. 2, the insulating substrate 6 is provided at a position farthest from the center C in the element arrangement surface 6a.

  In other words, each of one of the P-type and N-type thermoelectric elements connected to each other (for example, the four corner portion thermoelectric conversion elements 12 arranged at the corners in FIG. 2) is The insulating substrate 6 is provided at the farthest position along the diagonal L from the center C of the element placement surface 6a.

  Next, the material of each thermoelectric element will be described. The optimum material of the P-type thermoelectric conversion element 3 and the N-type thermoelectric conversion element 4 differs depending on the environmental temperature in which the thermoelectric conversion module 100 shown in FIG. 1 is used. Examples of thermoelectric materials include silicon-germanium, iron-silicon, bismuth-tellurium, magnesium-silicon, lead-tellurium, cobalt-antimony, bismuth-antimony, Heusler alloy or half-Heusler alloy. There is. The P-type thermoelectric conversion element 3 and the N-type thermoelectric conversion element 4 are preferably made of any combination of these materials.

  In the first embodiment, as an example, a mode in which a bonding material is melted and connected as shown in FIG. 3 will be described. By melting the high temperature side bonding material 11 when the thermoelectric conversion module 100 is assembled, the high temperature side electrode 10, the P-type thermoelectric conversion element (corner portion thermoelectric conversion element 12) 3, and the N-type thermoelectric conversion element 13 are heated to the high temperature side. The connection is made through the bonding material 11.

  Similarly, the low-temperature side electrode 15, the P-type thermoelectric conversion element (corner portion thermoelectric conversion element 12) 3, and the N-type thermoelectric conversion element 13 are melted when the low-temperature side bonding material 15 is melted when the thermoelectric conversion module 100 is assembled. Are connected via the low-temperature side bonding material 15.

  Further, although the low temperature side electrode 14 and the low temperature side insulating plate (insulating substrate 6) 16 are also connected, the bonding material is omitted in FIG. In the first embodiment, the example in which the thermoelectric conversion elements are connected using the low temperature side bonding material 15 and the high temperature side bonding material 11 has been described. However, a bonding method that does not use the bonding material, for example, room temperature bonding, diffusion bonding, and ultrasonic bonding. Such a joining method may be used.

  Further, the low temperature side electrode 14 and the low temperature side insulating plate 16 may be connected by using a bonding material such as brazing material, solder, or conductive adhesive, or a bonding material such as room temperature bonding, diffusion bonding, or ultrasonic bonding. Bonding that is not used is also acceptable.

  Moreover, as a material of the high temperature side bonding material 11 and the low temperature side bonding material 15, a metal material mainly containing any one of tin, indium, bismuth, zinc or aluminum, a brazing material such as silver brazing or aluminum brazing, or a silver paste Copper paste or metal oxide nanoparticles (silver, copper, etc.) are preferred.

  When soldering, in order to ensure the wettability of the solder, the wettability of the joint surface of the P-type thermoelectric conversion element 3 and the N-type thermoelectric conversion element 4 and the joint surface of the high temperature side electrode 10 and the low temperature side electrode 14 It is also possible to form a metal film such as nickel, gold, or copper that secures.

  Furthermore, since the material of the high temperature side electrode 10 and the low temperature side electrode 14 has a function as a wiring for conducting electricity, a metal having a low electric resistance, such as copper, aluminum, nickel, or gold, is desirable. The low temperature side insulating plate (insulating substrate 6) 16 may be made of an electrically insulating material such as ceramic, polyimide, printed circuit board, or flexible substrate.

  In the present embodiment, the insulating substrate (low temperature side insulating plate 16) 6 is formed only on the low temperature side. However, the insulating substrate 6 may be formed on the high temperature side, and the insulating substrate 6 is provided on both the low temperature side and the high temperature side. May not be formed.

  In addition, since the use environment of an industrial furnace and a motor vehicle is assumed about 200-900 degreeC, the temperature difference between the time of use of the thermoelectric conversion module 100 and a non-use becomes very large. At the time of use, the temperature difference between the high temperature side and the low temperature side is likely to be 100 to 800 degrees, and the temperatures on the upper and lower surfaces of the P-type thermoelectric conversion element (corner portion thermoelectric conversion element 12) 3 and the N-type thermoelectric conversion element 13 are high. The difference increases.

  When the temperature difference is large, stress or strain concentrates on the connection interface due to the difference in linear expansion coefficient between the P-type thermoelectric conversion element (corner portion thermoelectric conversion element 12) 3 and the N-type thermoelectric conversion element 13, and the electrode, There is a concern of breaking.

  In particular, when the size of the thermoelectric conversion module 100 is increased, the distance from the center of the thermoelectric conversion module 100 is increased. Therefore, the outer peripheral portion of the thermoelectric conversion module 100 (the peripheral portion of the element arrangement surface 6a of the insulating substrate 6), particularly the corner portion. Stress and strain concentrate on the surface.

  Therefore, in the first embodiment, a thermoelectric conversion element having a smaller connection area than a thermoelectric conversion element disposed at a location other than the corner portion and outer peripheral portion (peripheral portion) of the module (insulating substrate 6) is provided as a module ( A plurality of insulating substrates 6) are provided at the corners or the outer periphery (periphery).

  Thereby, in the thermoelectric conversion module 100 of this Embodiment 1, even when one element of a corner part fractures | ruptures with the stress accompanying a temperature change, an electrical continuity is not impaired.

  That is, according to the thermoelectric conversion module 100 of the first embodiment, even when stress is generated in the outer peripheral portion (peripheral portion) including the corner portion due to a temperature difference during use, a plurality of elements are arranged, so that the stress is Only the thermoelectric elements arranged at the locations where they tend to concentrate are damaged, and the other thermoelectric elements do not impair the electrical continuity and can prevent disconnection in the module.

  That is, by connecting and arranging a plurality of finely divided thermoelectric elements in parallel at a position where stress is likely to concentrate on the insulating substrate 6, when the stress is concentrated, the plurality of thermoelectric elements connected in parallel is arranged. Even if one of them is destroyed, the remaining thermoelectric elements keep the conduction, so that the entire thermoelectric conversion module can function sufficiently.

  As a result, the reliability of the thermoelectric conversion module 100 can be improved.

  In addition, the sum of the connection areas of the thermoelectric conversion elements in the corner portion is equal to or greater than the connection area of one thermoelectric conversion element other than the corner portion and the outer peripheral portion (peripheral portion). The efficiency of the entire module can be improved.

  Furthermore, by using a thermoelectric conversion element with a small connection area in the corner part or outer peripheral part (peripheral part), it is not necessary to use an electrode with a special shape in the corner part, so an electrode of the same size as the conventional one can be used. The thermoelectric conversion module performance equal to or higher than that of the conventional thermoelectric conversion module can be ensured without greatly changing the manufacturing process.

  Further, in the corner portion (corner portion) or the outer peripheral portion (peripheral portion) of the element arrangement surface 6a of the insulating substrate 6, the connection area with each electrode of one of the plurality of connected thermoelectric elements is the electrode of the other thermoelectric element. The connection area is small.

  As a result, when stress concentration occurs in the corner portion or outer peripheral portion (peripheral portion) of the insulating substrate 6, the most easily damaged thermoelectric element among the plurality of arranged thermoelectric elements is broken. As a result, it is possible to prevent the occurrence of disconnection in the corner portion or the outer peripheral portion (peripheral portion) of the insulating substrate 6.

  In the example shown in FIGS. 1 to 4, the case where a plurality of thermoelectric conversion elements are formed on the outer peripheral portion (peripheral portion) including the corner portion (corner portion) is described, but concentration of stress and strain is assumed. A similar effect can be obtained by forming a plurality of thermoelectric elements at a location, for example, in the vicinity of a module-shaped inflection point where the amount of deformation changes locally during expansion and contraction due to heat.

  The module-shaped inflection point is, for example, a portion where the largest temperature difference occurs in the insulating substrate 6. For example, when the inflection point is the central portion of the insulating substrate 6, A plurality of thermoelectric elements may be provided near the portion.

  Furthermore, although the case where the element of the corner portion is the P-type corner portion thermoelectric conversion element 12 is mainly described in the first embodiment, the thermoelectric element disposed in the corner portion may be an N-type thermoelectric conversion element. Good. Further, in the thermoelectric element, the shape of the connection surface may be any shape such as a quadrangle, a circle, an ellipse, or a polygon, but a circle or an ellipse is desirable from the viewpoint of stress relaxation.

  The lead-out wiring 5 in the thermoelectric conversion module 100 shown in FIG. 1 takes out the electric power generated in the P-type thermoelectric conversion element 3 and the N-type thermoelectric conversion element 4, and is made of copper, copper alloy, aluminum, aluminum alloy, or the like. Any conductive material may be used.

  The lead wire 5 can be joined to the low temperature side electrode 2 by any method as long as the joint can be maintained in the use environment, such as soldering, ultrasonic joining, diffusion joining, or conductive paste.

  Furthermore, in the thermoelectric conversion module 100 according to the first embodiment, the lead-out wiring 5 is connected to the low temperature side electrode 2 and electric power is taken out from the low temperature side, but is connected to the high temperature side electrode 1 and electric power is taken out from the high temperature side. May be.

(Embodiment 2)
The structure of the thermoelectric conversion module according to the second embodiment will be described with reference to FIGS. FIG. 5 is a plan transparent view showing an example of the element layout of the thermoelectric conversion module according to the second embodiment, and FIG. 6 is a side view showing an example of the element junction structure in the vicinity of the corner of the thermoelectric conversion module shown in FIG. is there. Here, differences from the thermoelectric conversion module 100 according to the first embodiment will be described.

  The thermoelectric conversion module 200 according to the second embodiment is different from the thermoelectric conversion module 100 according to the first embodiment in the structure of the corner portion thermoelectric conversion element 12.

  As shown in FIG. 5, the thermoelectric conversion module 200 according to the second embodiment divides the thermoelectric conversion element in the corner portion as in the first embodiment described above, but one thermoelectric conversion element (for example, a corner) It is characteristic that the partial thermoelectric conversion element 12) is divided by generating cracks in the vertical direction in the assembly of the module.

  According to the second embodiment, in addition to the features of the first embodiment, it is not necessary to install a plurality of elements in the corner portion during manufacturing, and the manufacturing process can be simplified.

  Here, a method for generating a crack when assembling the thermoelectric conversion module 200 will be described as an example of a method for forming a vertical crack in a thermoelectric element.

  In the thermoelectric conversion module 200, when connecting the low temperature side electrode and the thermoelectric conversion element, and when connecting the thermoelectric conversion element and the high temperature side electrode, a process of laminating these members and applying pressure and heating is widely used.

  As shown in FIG. 5, there are a plurality of P-type thermoelectric conversion elements and N-type thermoelectric conversion elements in one thermoelectric conversion module 200, and these thermoelectric elements are often connected together.

  A crack in the longitudinal direction is selectively and mechanically generated from these elements. Therefore, the height of the thermoelectric conversion element where the crack is to be generated is made higher than the height of the other thermoelectric conversion elements. Keep it. As a result, it is possible to selectively and mechanically generate longitudinal cracks by concentrating and applying a load to the thermoelectric element in which cracks are to be generated during the pressing process.

  In other words, in the second embodiment, during the pressurization process, a load is first applied to the thermoelectric element having a high height, and thus the thermoelectric element having a high height is divided into a plurality. Using this phenomenon, a plurality of thermoelectric elements having a high height are arranged on the outer peripheral portion (peripheral portion) of the insulating substrate 6.

  As a result, in the thermoelectric conversion module 200 shown in FIG. 6 assembled by this method, the corner portion thermoelectric conversion element 12 arranged in the corner portion is divided into a plurality of portions by the vertical cracks 12a. And each height of the corner part thermoelectric conversion element 12 is high compared with the thermoelectric element (N type thermoelectric conversion element 13 and P type thermoelectric conversion element 3) of another location (other than a corner part).

  If another expression is used, the height of one thermoelectric element (corner portion thermoelectric conversion element 12) connected in plural will be higher than the height of the other thermoelectric element (other than the corner portion) (N-type thermoelectric conversion element 13). high.

  Further, in the size of the element in plan view, as shown in FIG. 5, the thermoelectric element (corner portion thermoelectric conversion) having the same size as the thermoelectric element (N-type thermoelectric conversion element 13 or P-type thermoelectric conversion element 3) that does not generate cracks. Element 12) is used.

  Accordingly, as shown in FIG. 6, the connection area of each element (corner portion thermoelectric conversion element 12) formed by dividing by the vertical crack 12a by the above-described method is one thermoelectric element (N-type thermoelectric element) that does not generate a crack. It is smaller than the connection area of the conversion element 13).

  Thereby, the effect similar to the thermoelectric conversion module 100 of Embodiment 1 can be acquired also by the thermoelectric conversion module 200 of Embodiment 2. FIG.

  That is, according to the thermoelectric conversion module 200 of the second embodiment, even when stress is generated in the outer peripheral portion (peripheral portion) including the corner portion due to a temperature difference at the time of use, the vertical crack 12a formed during assembly causes the element ( The corner thermoelectric conversion element 12) is divided into a plurality of parts.

  As a result, even if one of the plurality of corner portion thermoelectric conversion elements 12 is damaged, the module does not impair electrical continuity and can prevent disconnection in the module.

  As a result, the reliability of the thermoelectric conversion module 200 can be improved.

  Also, in assembling the module, the vertical crack 12a is formed, and a thermoelectric conversion element (corner part thermoelectric conversion element 12) having a small connection area is arranged in the corner part or the outer peripheral part (peripheral part) in advance. It is not necessary to use an electrode having a different shape, and an electrode having the same size as the conventional one can be used.

  Thereby, the thermoelectric conversion module 200 can be assembled by the same assembly as the conventional thermoelectric conversion module, without largely changing the manufacturing process.

  In the second embodiment, the method of forming the plurality of corner portion thermoelectric conversion elements 12 by forming the vertical cracks 12a at the time of assembly has been described. In this case, each of the plurality of connected corner portion thermoelectric conversion elements 12 is described. The size of the connection area with the electrode varies from element to element.

  Therefore, when another expression is used, the size of the connection area with each electrode of the plurality of corner portion thermoelectric conversion elements 12 becomes a plurality of types.

  Further, in the thermoelectric conversion module 200 of the second embodiment, as shown in FIG. 6, the height of the thermoelectric element that has generated the vertical crack 12 a is higher than the thermoelectric elements in other locations. The thickness of each joint part of the high temperature side joining material 11 and the low temperature side joining material 15 becomes thin.

  Thereby, the electrical resistance of a junction part and thermal resistance can be made low, and the characteristic of the thermoelectric conversion module 200 can be improved.

(Embodiment 3)
The structure of the thermoelectric conversion module according to the third embodiment will be described with reference to FIG. FIG. 7 is a side view showing an example of an element joint structure in the vicinity of a corner portion of the thermoelectric conversion module according to the third embodiment. FIG. 8 is a plan transparent view showing an element layout of a thermoelectric conversion module according to a modification of the third embodiment of the present invention.

  Here, differences from the thermoelectric conversion module 200 according to the second embodiment will be described.

  The difference between the thermoelectric conversion module 300 of Embodiment 3 and the thermoelectric conversion module 200 of Embodiment 2 is that the corner portion thermoelectric conversion element 12 is divided into a plurality of parts in advance.

  That is, the plurality of corner portion thermoelectric conversion elements 12 of the thermoelectric conversion module 200 described above are divided into a plurality of parts by forming vertical cracks 12a during the pressurizing process of assembling the module. In the thermoelectric conversion module 300, the module is assembled by arranging the corner portion thermoelectric conversion elements 12 previously divided (divided) into a plurality of pieces on the low temperature side electrode 14.

  The height of the corner portion thermoelectric conversion element 12 is similar to that of the thermoelectric conversion module 200 in comparison with thermoelectric conversion elements (N-type thermoelectric conversion element 13 and P-type thermoelectric conversion element 3) at other locations (other than the corner portion). It is high.

  With the thermoelectric conversion module 300 according to the third embodiment, the connection area of the thermoelectric conversion element (corner part thermoelectric conversion element 12) in the corner portion is changed in advance to the thermoelectric conversion element (N-type thermoelectric conversion element 13 or P-type thermoelectric conversion) in another location. The element 3) can be reliably made smaller.

  That is, instead of being mechanically divided at the time of assembly as in the thermoelectric conversion module 200 of the second embodiment, it is separated into pieces that have a smaller connection area than the N-type thermoelectric conversion element 13 and the P-type thermoelectric conversion element 3. A plurality of corner portion thermoelectric conversion elements 12 are prepared in advance, and the plurality of corner portion thermoelectric conversion elements 12 are arranged on the low temperature side electrode 14 to assemble a module.

  As a result, the degree of freedom in layout of the thermoelectric conversion elements in the corner portion is increased, and the connection area of each thermoelectric conversion element (corner portion thermoelectric conversion element 12) in the corner portion is changed to the thermoelectric conversion element (N-type thermoelectric element) in another location. Since it can be surely made smaller than the conversion element 13 or the P-type thermoelectric conversion element 3), it is possible to arrange elements that reduce the influence of stress.

  Here, a modification shown in FIG. 8 will be described. Since the thermoelectric conversion module 300 according to the third embodiment uses a plurality of corner portion thermoelectric conversion elements 12 that are divided in advance, the plurality of corner portion thermoelectric conversion elements 12 have a plurality of types of connection areas. It is also possible to do.

  Therefore, as shown in FIG. 8, as an element arrangement in consideration of reducing the influence of stress, as shown in FIG. 8, each of the thermoelectric elements (corner portion thermoelectric conversion elements 12) connected to each other is connected to the electrode of each thermoelectric element. The connection area of the corner portion thermoelectric conversion element 12 at a position closer to the center C of the insulating substrate 6 is larger than the connection area of the corner portion thermoelectric conversion element 12 at a position farther from the center C of the insulating substrate 6. large.

  Specifically, the connection area of the corner portion thermoelectric conversion element 12 provided at a position near the center C of the element arrangement surface 6 a of the insulating substrate 6 is farther from the center C of the element arrangement surface 6 a of the insulating substrate 6. It is larger than the connection area of the provided corner portion thermoelectric conversion element 12.

  That is, in the element arrangement surface 6a of the insulating substrate 6, the connection area with the electrode of the corner portion thermoelectric conversion element 12 at a position farther from the center C of the substrate is the same as the electrode of the corner portion thermoelectric conversion element 12 at a position close to the center C. The size of the thermoelectric element is smaller than the connection area.

  In this case, there are a plurality of types (two types) of connection areas with the electrodes of one of the plurality of thermoelectric elements (corner portion thermoelectric conversion elements 12) connected.

  As a result, a greater stress is applied to the thermoelectric element at a position farther from the center C. Therefore, the corner portion thermoelectric conversion element 12 having a smaller connection area far from the center C is damaged, and the other connection, particularly the most connected. The corner thermoelectric conversion element 12 having a large area can be left.

  Thus, even if one of the plurality of corner portion thermoelectric conversion elements 12 having a small connection area is damaged, the electrical continuity of the module is not impaired.

  As described above, according to the thermoelectric conversion module 300 of the third embodiment, even when stress is generated in the outer peripheral portion (peripheral portion) including the corner portion due to a temperature difference at the time of use, the element (corner portion thermoelectric conversion element) is divided in advance. 12) is used, the influence of stress can be reduced.

  In this case, even if one of the plurality of corner portion thermoelectric conversion elements 12 is damaged, the electrical continuity of the module is not impaired, and disconnection in the module can be prevented.

  As a result, the reliability of the thermoelectric conversion module 300 can be improved.

  The thermoelectric conversion modules 200 and 300 according to the second embodiment and the third embodiment can be manufactured by the same method as the thermoelectric conversion module 100 according to the first embodiment. In other words, even when the shape of the corner portion or the like is the above shape, there is no newly required process in addition to the assembly method of the first embodiment.

  Moreover, the shape of the high temperature side electrode 1 and the low temperature side electrode 2 is not limited to the shape shown in FIG.

  As mentioned above, the invention made by the present inventor has been specifically described based on the embodiments of the invention. However, the present invention is not limited to the embodiments of the invention, and various modifications can be made without departing from the scope of the invention. Is possible.

  In addition, this invention is not limited to above-described embodiment, Various modifications are included. For example, the above-described embodiment has been described in detail for easy understanding of the present invention, and is not necessarily limited to one having all the configurations described.

  Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. . In addition, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment. In addition, each member and relative size which were described in drawing are simplified and idealized in order to demonstrate this invention clearly, and it becomes a more complicated shape on mounting.

  In the example shown in FIGS. 1 to 8, the case where the planar shape and the size of the electrode to which the P-type thermoelectric element and the N-type thermoelectric element are connected is one type has been described. The planar shape and the size thereof are not limited to one type, and may be a plurality of types.

DESCRIPTION OF SYMBOLS 1 High temperature side electrode 2 Low temperature side electrode 3 P type thermoelectric conversion element 4 N type thermoelectric conversion element 5 Lead-out wiring 6 Insulating substrate 6a Element arrangement surface 10 High temperature side electrode 11 High temperature side bonding material 12 Corner part thermoelectric conversion element 12a Vertical crack 13 N Type thermoelectric conversion element 14 low temperature side electrode 15 low temperature side bonding material 16 low temperature side insulating plate 100, 200, 300 thermoelectric conversion module

Claims (13)

An insulating substrate on which electrodes are disposed;
A P-type thermoelectric element disposed on the insulating substrate;
An N-type thermoelectric element disposed on the insulating substrate;
Have
A plurality of thermoelectric elements of either the P-type or the N-type are connected to the electrode, and the other thermoelectric element of the P-type or the N-type is connected,
The thermoelectric conversion module, wherein a sum of connection areas of the plurality of the one connected thermoelectric elements with the electrodes is equal to or greater than a connection area of the other thermoelectric element with the electrodes. The thermoelectric conversion module according to claim 1,
The thermoelectric conversion module, wherein the plurality of one connected thermoelectric elements are provided at a peripheral portion of an element arrangement surface of the insulating substrate. In the thermoelectric conversion module according to claim 2,
The one or more connected thermoelectric elements are thermoelectric conversion modules provided at corners of the peripheral edge of the element arrangement surface of the insulating substrate. The thermoelectric conversion module according to claim 1,
The thermoelectric conversion module, wherein the one or more connected thermoelectric elements are provided at a position farthest from the center of the element placement surface of the insulating substrate in the arrangement of the thermoelectric elements. The thermoelectric conversion module according to claim 1,
Each of the one connected thermoelectric elements is a thermoelectric conversion module provided at a position farthest along a diagonal line from the center of the element arrangement surface of the insulating substrate. The thermoelectric conversion module according to claim 1,
The thermoelectric conversion module, wherein a connection area between each of the one connected thermoelectric elements and the electrode is smaller than a connection area between the other thermoelectric element and the electrode. The thermoelectric conversion module according to claim 1,
The thermoelectric conversion module, wherein each of the plurality of one thermoelectric elements connected to each other has a height higher than that of the other thermoelectric element. The thermoelectric conversion module according to claim 1,
The thermoelectric conversion module is a plurality of types of sizes of connection areas of the plurality of one-connected thermoelectric elements with the electrodes. In the thermoelectric conversion module according to claim 8,
The size of the connection area between each of the one connected thermoelectric elements and the electrodes is larger than the connection area of the thermoelectric elements provided at a position closer to the center of the element arrangement surface of the insulating substrate. A thermoelectric conversion module that is larger than a connection area of the thermoelectric elements provided at a position far from the center of the element arrangement surface of the insulating substrate. The thermoelectric conversion module according to claim 1,
The connection between the P-type thermoelectric element and the N-type thermoelectric element is in series,
The thermoelectric conversion module, wherein the plurality of one connected thermoelectric elements are connected in parallel to the electrodes. In the thermoelectric conversion module according to claim 10,
The thermoelectric conversion module, wherein a connection area of each of the plurality of thermoelectric elements connected in parallel to the electrodes is smaller than a connection area of the thermoelectric elements connected in series. In the thermoelectric conversion module according to claim 10,
The thermoelectric conversion module, wherein a sum of connection areas of the thermoelectric elements connected in parallel with the electrodes is equal to or greater than a connection area of the thermoelectric elements connected in series with the electrodes. The thermoelectric conversion module according to claim 1,
A plurality of the electrodes are disposed on the insulating substrate,
The thermoelectric conversion module, wherein the plurality of electrodes have the same size in plan view.

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