JP4826310B2 - Thermoelectric module - Google Patents

Description

  The present invention relates to a thermoelectric module, and more particularly, to a thermoelectric module having excellent heat stress and high reliability.

  The thermoelectric module is composed of a p-type semiconductor and an n-type semiconductor microchip (thermoelectric element) containing at least two elements selected from the group consisting of Bi, Sb, Te, and Se on a ceramic substrate with patterned electrodes. It is used to adjust the temperature by using the Seebeck effect that generates electromotive force when a temperature difference occurs between the contacts and converting the heat into electric power or by generating the temperature difference by energization. is there.

FIG. 4 is a schematic front view showing a conventional thermoelectric module. The thermoelectric elements 21 and 22 and the electrodes 24 and 28 are usually joined by soldering with a solder alloy such as Pb-Sn, Sn-Sb, or Au-Sn, but the thermoelectric elements 21 and 22 and the electrodes 24 and 28 are joined together. By interposing the solder 25 between them, the solder 25 becomes a thermal resistance, which hinders heat transfer and heat conduction, and raises the electric resistance, which becomes one of the factors hindering the power generation efficiency of the thermoelectric module 20. Further, as shown in FIG. 5, when the drives the thermoelectric module 20, the thermal stress is generated due to the difference in thermal expansion between the upper and lower substrates by a temperature difference between the upper and lower substrates, the thermal stress thermoelectric element 2 1及 since applied to the solder joint between the fine heat Denmoto terminal 2 2 and the electrodes 24 and 28, there is a possibility of breaking at the junction or the like, there is a problem of low reliability of the thermoelectric module 20.

  In order to solve this problem, the technique disclosed in Patent Document 1 forms the electrode 34 on the high temperature end side so as to have a gently convex curved surface, and the thermoelectric elements 31 and 32 and the electrode 34 on the high temperature end side. In addition, bonding to the electrode 38 on the low temperature end side is not performed by soldering but by applying liquid metal solder made of Hg, Ga, In or an alloy thereof to both the thermoelectric elements 31 and 32 and the electrodes 34 and 38. Yes. FIG. 6 shows a schematic front view showing the thermoelectric module 30 disclosed in Patent Document 1. As shown in FIG. Since the electrode 34 at the high temperature end has a gently convex curved surface, at the time of bonding, the liquid metal 36 responsible for the bonding is pushed to the side portions of the thermoelectric elements 31 and 32 by the thermoelectric elements 31 and 32. The bonding surface between the elements 31 and 32 and the electrode 34 is an extremely thin liquid metal surface. This prevents an increase in thermal resistance and electrical resistance, and since the thermoelectric elements 31 and 32 and the electrodes 34 and 38 are joined by the liquid metal 36, the joint is caused by a difference in thermal expansion between the upper and lower substrates. It is not affected by thermal stress.

JP 2003-37300 A

  However, since the technique disclosed in Patent Document 1 joins all the thermoelectric elements 31 and 32 and the electrodes 34 and 38 with the liquid metal 36, the thermoelectric elements 31 and 32 are used when the thermoelectric module 30 is handled. There is a problem that movement, poor contact, or short-circuiting may occur. Further, the surface of the thermoelectric elements 31 and 32 is plated with nickel by electroless plating or the like, but when the liquid metal 36 is applied to the nickel surface, the wettability is poor, which increases the contact resistance, and the thermoelectric module. When 30 is used as a power generation element, there is a problem that power generation efficiency is reduced, and when it is used as a temperature control element, heat absorption efficiency is reduced.

  The present invention has been made in view of such problems, and an object thereof is to provide a thermoelectric module that is excellent in heat stress, has good handling properties, has high power generation efficiency, and high reliability.

The thermoelectric module according to the present invention includes a first substrate as a high temperature end, a plurality of first electrodes formed on the first substrate, a second substrate as a low temperature end, and the second substrate. A plurality of second electrodes formed on the substrate, a plurality of p-type thermoelectric elements, and a plurality of n-type thermoelectric elements, and each of the first electrodes has a pair of the above-described one pair. An adjacent p-type thermoelectric element and n-type thermoelectric element among a p-type thermoelectric element and an n-type thermoelectric element bonded to a pair of adjacent first electrodes, the p-type thermoelectric element and the n-type thermoelectric element being bonded Is connected to one second electrode, and the plurality of p-type thermoelectric elements and n-type thermoelectric elements are alternately connected in series, wherein the plurality of p-type thermoelectric elements and the plurality of p-type thermoelectric elements are connected to the second electrode . The n-type thermoelectric elements have the same height, and the amount of thermal expansion of the diagonal length of the first substrate is the p-type thermoelectric element. Child and numerical R divided by the cube of the height the n-type thermoelectric element is at 0.039 or more, the central portion of the first substrate is less than the value of the R is 0.039, the second 1 electrode, the p-type thermoelectric element, and the n-type thermoelectric element are joined by soldering, and the portion other than the center portion has a value of R of 0.039 or more, and the first electrode and the n-type thermoelectric element The p-type thermoelectric element and the n-type thermoelectric element are electrically connected by a liquid metal that is liquid at the temperature of the first substrate during operation of the thermoelectric module, and the second electrode and the p-type thermoelectric element And the n-type thermoelectric element are all joined by soldering, and the surfaces of the p-type thermoelectric element and the n-type thermoelectric element to be joined to the first electrode and the second electrode are AuSn plated or SnSb. that is plated And features.

In the thermoelectric module, for example, the liquid metal is liquid at 25 to 250 ° C.

The method of manufacturing a thermoelectric module according to the present invention includes a p-type thermoelectric element in which a pair of p-type thermoelectric elements and an n-type thermoelectric element are joined to a first electrode and joined to a pair of adjacent first electrodes. And n-type thermoelectric elements, adjacent p-type thermoelectric elements and n-type thermoelectric elements are joined to one second electrode, and a plurality of p-type thermoelectric elements and n-type thermoelectric elements are alternately connected in series. In the module manufacturing method, using a p-type thermoelectric element and an n-type thermoelectric element having the same height obtained by applying AuSn plating or SnSb plating to the surfaces to be joined to the first electrode and the second electrode, A substrate provided with a first electrode and having a numerical value R obtained by dividing the amount of thermal expansion of the diagonal length by the cube of the height of the p-type thermoelectric element and the n-type thermoelectric element is 0.039 or higher. It was used as the first substrate as the central portion of the first substrate Said less than the value of R is 0.039, and bonding by soldering to place p-type thermoelectric elements and the n-type thermoelectric elements each pair to said first electrode of the central portion, the first The portion other than the central portion of one substrate has a value of R of 0.039 or more, and a pair of p-type thermoelectric elements and n-type thermoelectric elements are respectively applied to the first electrodes in the portions other than the central portion. a second substrate of a step of electrically connecting the liquid metal which is liquid at a temperature of the first substrate during operation of the thermoelectric modules arranged to the substrate on which the second electrode is provided as a cold end Of p-type thermoelectric elements and n-type thermoelectric elements that are adjacent to each other by the second electrode provided on the second substrate, and are adjacent to each other. and n-type thermoelectric elements to one of said second electrodes And having it and bonding by attaching the.

In the manufacturing method of the thermoelectric module, for example, the liquid metal is liquid at 25 to 250 ° C.

  According to the present invention, at the low temperature end where the thermal expansion of the substrate is small, the electrode and the thermoelectric element are joined by soldering, while at the high temperature end where the thermal expansion of the substrate is large, the influence of the thermal expansion is small near the center of the substrate. Since the electrode and the thermoelectric element are joined by soldering, and the electrode and the thermoelectric element are joined by liquid metal except in the vicinity of the center of the substrate which is largely displaced by thermal expansion, the thermoelectric element and the solder joint portion between the thermoelectric element and the electrode However, there is no influence of thermal stress caused by the difference in thermal expansion between the high temperature end and the low temperature end, and there is no possibility of breaking at the joint or the like, and a highly reliable thermoelectric module can be obtained. Also, the electrode and the thermoelectric element are joined by soldering in the vicinity of the center of the substrate at the high temperature end and the low temperature end, so that the handling property is good. Since it is joined by metal, contact resistance can be suppressed, and a thermoelectric module with high power generation efficiency can be obtained.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the accompanying drawings. FIG. 1 is a schematic front view showing a thermoelectric module according to the first embodiment of the present invention. Diffusion prevention barrier layers (not shown) that prevent composition change due to diffusion between different materials are formed on the upper and lower surfaces (surfaces to be joined) of the p-type thermoelectric element 1 and the n-type thermoelectric element 2, and a liquid is further formed thereon. A metal layer (not shown) such as Sn for improving metal wettability is formed.

  On the lower electrode 4 as the first electrode patterned on the lower substrate 3 as the high temperature end (first substrate), one thermoelectric element is arranged at the end, and other than the end One p-type thermoelectric element 1 and one n-type thermoelectric element 2 are arranged on one lower electrode 4. The lower electrode 4 and the p-type thermoelectric element 1 and the n-type thermoelectric element 2 are joined by soldering in the vicinity of the central portion of the lower substrate 3, and the lower electrode 4 and the p-type are connected except for the vicinity of the central portion of the lower substrate 3. The thermoelectric element 1 and the n-type thermoelectric element 2 are joined by the liquid metal 6. Thereby, the adjacent p-type thermoelectric element 1 and n-type thermoelectric element 2 are electrically connected.

  Further, an upper substrate 7 having an upper electrode 8 (second electrode) formed on the lower surface as a low temperature end (second substrate) is adjacent to the p-type thermoelectric element 1 and the n-type thermoelectric element 2. The n-type thermoelectric element 2 on one lower electrode 4 and the p-type thermoelectric element 1 on the other lower electrode 4 in the two lower electrodes 4 are arranged so as to be joined to one upper electrode 8, Upper electrode 8, p-type thermoelectric element 1 and n-type thermoelectric element 2 are joined by soldering. Thus, the thermoelectric module 10 in which the p-type thermoelectric elements 1 and the n-type thermoelectric elements 2 are alternately connected in series is formed by the upper electrode 8 and the lower electrode 4.

  As shown in FIG. 2, the reliability of the thermoelectric module 10 due to thermal stress depends on the following Equation 1, and it was found that the thermoelectric module 10 is damaged when R ≧ 0.039. Here, J is the thermal expansion amount of the diagonal length of the substrate at the high temperature end of the thermoelectric module, and H is the height (chip height) of the thermoelectric element.

  Therefore, in the region where the outermost peripheral part of the central thermoelectric element from the center of the substrate of the thermoelectric module 10 satisfies R <0.039 in Equation 1 shown above as the vicinity of the central part of the lower substrate 3 described above, the lower electrode 4 and the p-type The thermoelectric element 1 and the n-type thermoelectric element 2 are joined by soldering, and the outermost peripheral portion of the central thermoelectric element from the center of the thermoelectric module 10 to the center of the thermoelectric module 10 except for the vicinity of the central portion of the lower substrate 3 is R ≧ In a region satisfying 0.039, it is preferable that the lower electrode 4 and the p-type thermoelectric element 1 and the n-type thermoelectric element 2 are joined by the liquid metal 6.

  Diffusion prevention barrier layers (not shown) are formed on the upper and lower surfaces (surfaces joined to the upper electrode 8 and the lower electrode 4) of the p-type thermoelectric element 1 and the n-type thermoelectric element 2, and further the liquid metal 6 is formed thereon. In order to improve the wettability of the metal, a metal layer (not shown) such as Sn is formed by AuSn plating or SnSb plating, so that diffusion between different materials in the p-type thermoelectric element 1 and the n-type thermoelectric element 2 It is possible to prevent a change in composition due to the above, and it is possible to prevent an increase in contact resistance between the thermoelectric element and the electrode because good liquid metal wettability can be obtained.

  Also, the electrode and the thermoelectric element are joined by soldering at the low temperature end (upper substrate 7), and the thermal expansion of the thermoelectric module near the center of the thermoelectric module is less affected at the high temperature end (lower substrate 3) where the thermal expansion of the substrate is large. (A region satisfying R <0.039 in Equation 1 above) The electrode and the thermoelectric element are joined by soldering, and other than near the center of the substrate of the thermoelectric module (region satisfying R ≧ 0.039 in Equation 1 above). By joining the electrode and the thermoelectric element with a liquid metal, a thermoelectric module having good handling properties and excellent heat stress can be obtained.

  Next, the operation of the thermoelectric module 10 of the present embodiment configured as described above will be described. A temperature difference is generated between the low temperature end (upper substrate 7) and the high temperature end (lower substrate 3) of the thermoelectric module 10 to drive the thermoelectric module 10. At this time, since the temperature of the high temperature end (lower substrate 3) is higher than that of the low temperature end (upper substrate 7), the high temperature end (lower substrate 3) is more thermally expanded than the low temperature end (upper substrate 7), Thermal stress due to the difference in thermal expansion between the high temperature end (lower substrate 3) and the low temperature end (upper substrate 7) is applied to the thermoelectric element and the solder joint between the thermoelectric element and the electrode.

  At the low temperature end (upper substrate 7) where the thermal expansion of the substrate is small, the electrode and the thermoelectric element are joined by the solder 5, while at the high temperature end (lower substrate 3) where the thermal expansion of the substrate is large, the influence of thermal expansion. The electrode and the thermoelectric element are joined by the solder 5 in the vicinity of the center of the substrate with a small amount, and the thermoelectric element and the thermoelectric element are joined by the liquid metal 6 in the vicinity of the substrate other than the vicinity of the center of the substrate that is largely displaced by thermal expansion. The solder joint between the thermoelectric element and the electrode is not affected by the thermal stress caused by the thermal expansion difference between the high temperature end (lower substrate 3) and the low temperature end (upper substrate 7), and there is no possibility of breaking at the joint or the like. .

  Hereinafter, examples for demonstrating the effects of the present invention will be described in comparison with comparative examples that are out of the scope of the present invention. Evaluation was made on a small Peltier module for temperature control of an LD (Laser Diode) for optical communication, a large Peltier module for general cooling, and a large Seebeck module for power generation as thermoelectric modules.

  As a comparative example, unlike the thermoelectric module 10 according to the first embodiment, all the bonding between the electrode and the thermoelectric element is performed by soldering, all the bonding between the electrode and the thermoelectric element is performed by the liquid metal 6, As shown in FIG. 3, the electrodes and the thermoelectric elements are all joined together by the liquid metal 6 at the high temperature end (lower substrate 3) where thermal expansion is large when the thermoelectric module 11 is driven, and the low temperature end (upper substrate 7). The electrode and the thermoelectric element were all joined by soldering. 3, the same components as those of FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

  As an item for judging the quality of each created thermoelectric module, the difference (ΔACR) between the thermoelectric module resistance calculated from the electric resistance of the thermoelectric element used for assembly and the AC resistance of the actually produced thermoelectric module was evaluated. The ΔACR component is a resistance added by other than the thermoelectric element such as an electrode and a solder joint part, and these generate Joule heat, which deteriorates the performance of the thermoelectric module. In general, when ΔACR exceeds 5%, this Joule heat cannot be ignored, which is undesirable.

  In addition, the reliability test of thermoelectric modules assumes an environment where it is actually used, and power cycle tests (intermittent energization at a high temperature end of 85 ° C and a low temperature end of 25 ° C for a small Peltier module for temperature control of an optical communication LD. ) And an impact test (a drop test with a 5 g weight applied to the low temperature end).

  A power cycle test (500 cycles of intermittent energization at a high temperature end of 25 ° C. and a low temperature end of −45 ° C.) and an impact test (a drop test with a 100 g weight applied to the low temperature end) were performed on the large-sized Peltier module for general-purpose cooling. .

  The large-scale Seebeck module for power generation was subjected to a continuous power generation test (a power generation test for 500 hours at a high temperature end of 250 ° C. and a low temperature end of 50 ° C.) and an impact test (a drop test with a 100 g weight applied to the low temperature end).

  As described above, when ΔACR exceeds 5%, this Joule heat becomes negligible. Therefore, the case where the change in ACR exceeds 5% before and after the reliability test of the thermoelectric module is indicated as x. Here, the chip height is the height H of the p-type thermoelectric element 1 and the n-type thermoelectric element 2, the chip cross-section is the cross-section of the junction surface with the electrodes of the p-type thermoelectric element 1 and the n-type thermoelectric element 2, and the logarithm is p. The number of thermoelectric element pairs existing in each thermoelectric module when the n-type thermoelectric element 1 and the n-type thermoelectric element 2 are paired, the element junction is the junction between the p-type thermoelectric element 1 and the n-type thermoelectric element 2 and the electrode The metal and element plating treatment used in the above is the type of plating treatment performed for joining the electrodes of the p-type thermoelectric element 1 and the n-type thermoelectric element 2.

  Table 1 below shows the evaluation results of a small Peltier module for temperature control of an optical communication LD. As can be seen from Examples 1 to 3 and Comparative Examples 4 and 5, the electrode and the thermoelectric element are bonded to each other by the liquid metal 6 (Comparative Example 4) and at the high temperature end (lower substrate 3). In the case where all of these are joined by the liquid metal 6 (Comparative Example 5), the electrode and the thermoelectric element are joined by soldering in the vicinity of the center of the substrate at the low temperature end (upper substrate 7) and the high temperature end (lower substrate 3). The amount of change in ACR before and after the impact test was larger than that in the case where the electrode and the thermoelectric element were joined by a liquid metal except in the vicinity of the center of the substrate of (lower substrate 3) and exceeded 5%. In addition, when the thermoelectric module is in the range of R ≧ 0.039 shown in the above mathematical formula 1, all the electrodes and thermoelectric elements joined by soldering (Comparative Example 3) are the changes in ACR before and after the power cycle test. Was over 5%.

  Table 2 below shows the evaluation results of the general-purpose cooling large Peltier module. As can be seen from Example 7 and Comparative Example 8, when the thermoelectric module is in the range of R ≧ 0.039 shown in Equation 1, the electrode and the thermoelectric element are all joined by soldering (Comparative Example 8). The electrode and the thermoelectric element are joined to each other by soldering in the vicinity of the center of the substrate at the low temperature end (upper substrate 7) and the high temperature end (lower substrate 3), and the electrode and the thermoelectric are connected except at the center of the substrate at the high temperature end (lower substrate 3). The amount of change in ACR before and after the power cycle test was larger than that obtained by joining the device with a liquid metal (Example 7) and exceeded 5%.

  Further, as can be seen from Example 7 and Comparative Examples 9 and 10, the electrode and the thermoelectric element are bonded to each other by the liquid metal 6 (Comparative Example 9) and the high temperature end (lower substrate 3). In which all of the electrodes are joined by the liquid metal 6 (Comparative Example 10), the electrode and the thermoelectric element are joined by soldering in the vicinity of the center of the substrate at the low temperature end (upper substrate 7) and the high temperature end (lower substrate 3). The amount of change in ACR before and after the impact test was larger than that in which the electrode and the thermoelectric element were joined by liquid metal except in the vicinity of the substrate center of (lower substrate 3), and exceeded 5%.

  Table 3 below shows the evaluation results of the large-scale power generation Seebeck module. As can be seen from Example 8 and Comparative Example 11, when the thermoelectric module is in the range of R ≧ 0.039 shown in Equation 1, the electrode and the thermoelectric element are all joined by soldering (Comparative Example 11). The electrode and the thermoelectric element are joined to each other by soldering in the vicinity of the center of the substrate at the low temperature end (upper substrate 7) and the high temperature end (lower substrate 3), and the electrode and the thermoelectric are connected except at the center of the substrate at the high temperature end (lower substrate 3). The amount of change in ACR before and after the power cycle test was larger than that obtained by bonding the device to the liquid metal (Example 8), exceeding 5%.

  Further, as can be seen from Example 8 and Comparative Examples 12 and 13, the electrode and the thermoelectric element at the high temperature end (lower substrate 3) and the electrode and the thermoelectric element all joined by the liquid metal 6 (Comparative Example 12) In which all the electrodes are joined by the liquid metal 6 (Comparative Example 13), the electrode and the thermoelectric element are joined by soldering in the vicinity of the center of the substrate at the low temperature end (upper substrate 7) and the high temperature end (lower substrate 3). The amount of change in ACR before and after the impact test was larger than that in which the electrode and the thermoelectric element were joined by liquid metal except in the vicinity of the center of the lower substrate 3 (Example 8) and exceeded 5%.

  Thereby, when the thermoelectric module is in the range of R ≧ 0.039 shown in the above mathematical formula 1, the electrode and the thermoelectric element are joined by soldering at the low temperature end (upper substrate 7) where the thermal expansion of the substrate is small, The electrode and the thermoelectric element are joined by soldering in the vicinity of the center of the substrate where the thermal expansion of the substrate is large (lower substrate 3) where the thermal expansion is small (region satisfying R <0.039 shown in the above formula), ACR changes in power cycle tests and impact tests by joining the electrodes and thermoelectric elements with the liquid metal 6 outside the vicinity of the center of the substrate that is largely displaced by thermal expansion (region satisfying R ≧ 0.039 shown in the above formula). The minutes could be reduced to 5%.

It is a typical front view which shows the thermoelectric module which concerns on 1st Embodiment of this invention. H ³ and is a graph showing the relationship between ^{R (= J / H 3)} . It is a typical front view which shows the thermoelectric module of a comparative example. It is a typical front view which shows the conventional thermoelectric module. It is a typical front view which shows a mode when the thermoelectric module shown in FIG. 4 is driven. It is a typical front view which shows the conventional thermoelectric module.

Explanation of symbols

1; p-type thermoelectric element, 2; n-type thermoelectric element, 3; lower substrate (high temperature end), 4; lower electrode, 5; solder, 6; liquid metal, 7; upper substrate (low temperature end), 8; 10; thermoelectric module, 20; thermoelectric module, 21; p-type thermoelectric element, 22; n-type thermoelectric element, 23; lower substrate (high temperature end), 24; lower electrode, 25; solder, 27; ), 28; upper electrode, 30; thermoelectric module, 31; p-type thermoelectric element, 32; n-type thermoelectric element, 33; lower substrate (high temperature end), 34; lower electrode, 36; liquid metal, 37; Cold end), 38; upper electrode

Claims (4)

A first substrate as a high temperature end, a plurality of first electrodes formed on the first substrate, a second substrate as a low temperature end, and a plurality formed on the second substrate Each of the second electrodes, a plurality of p-type thermoelectric elements, and a plurality of n-type thermoelectric elements, and each of the first electrodes has a pair of the p-type thermoelectric element and the n-type. Among the p-type thermoelectric element and the n-type thermoelectric element bonded to the pair of adjacent first electrodes, each of the second p-type thermoelectric element and the n-type thermoelectric element is one second. In a thermoelectric module in which the plurality of p-type thermoelectric elements and n-type thermoelectric elements are alternately connected in series by being bonded to an electrode,
The plurality of p-type thermoelectric elements and the plurality of n-type thermoelectric elements are equal in height,
A numerical value R obtained by dividing the amount of thermal expansion of the diagonal length of the first substrate by the cube of the height of the p-type thermoelectric element and the n-type thermoelectric element is 0.039 or more,
The central portion of the first substrate has an R value of less than 0.039, and the first electrode, the p-type thermoelectric element, and the n-type thermoelectric element are joined by soldering,
The portion other than the central portion has a value of R of 0.039 or more, and the first electrode, the p-type thermoelectric element, and the n-type thermoelectric element are connected to each other during the operation of the thermoelectric module. Electrically connected by a liquid metal that is liquid at the temperature of the substrate ,
The second electrode, the p-type thermoelectric element and the n-type thermoelectric element are all joined by soldering ,
A thermoelectric module characterized in that AuSn plating or SnSb plating is applied to the surfaces of the p-type thermoelectric element and the n-type thermoelectric element to be joined to the first electrode and the second electrode . The thermoelectric module according to claim 1, wherein the liquid metal is liquid at 25 to 250 ° C. A pair of p-type thermoelectric elements and n-type thermoelectric elements are bonded to the first electrode, and adjacent p-type of the p-type thermoelectric elements and n-type thermoelectric elements bonded to the adjacent pair of the first electrodes. In the method of manufacturing a thermoelectric module in which a thermoelectric element and an n-type thermoelectric element are joined to one second electrode, and a plurality of p-type thermoelectric elements and n-type thermoelectric elements are alternately connected in series.
Using a p-type thermoelectric element and an n-type thermoelectric element having the same height in which AuSn plating or SnSb plating is applied to the surface joined to the first electrode and the second electrode,
A substrate provided with the first electrode and having a numerical value R obtained by dividing the diagonal thermal expansion amount by the cube of the height of the p-type thermoelectric element and the n-type thermoelectric element is 0.039 or higher. It is used as a first substrate as an end. The central portion of the first substrate has a value of R of less than 0.039, and a pair of p-type thermoelectric elements are connected to the first electrode in the central portion. Arranging the element and the n-type thermoelectric element and joining them by soldering;
The portion of the first substrate other than the central portion has a value of R of 0.039 or more, and a pair of p-type thermoelectric elements and n-type thermoelectric elements are respectively connected to the first electrodes of the portions other than the central portion. Arranging the elements and electrically connecting them with liquid metal that is liquid at the temperature of the first substrate during operation of the thermoelectric module ;
The substrate provided with the second electrode is used as a second substrate as a low temperature end, and is bonded to the pair of adjacent first electrodes by the second electrode provided on the second substrate. Bonding adjacent p-type thermoelectric elements and n-type thermoelectric elements among the p-type thermoelectric elements and n-type thermoelectric elements to one second electrode by soldering;
The manufacturing method of the thermoelectric module characterized by having. The method of manufacturing a thermoelectric module according to claim 3, wherein the liquid metal is liquid at 25 to 250 ° C. 5.

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