JP2009289860A - Thermoelectric conversion module and method for manufacturing thermoelectric conversion module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoelectric conversion module capable of raising output per unit area as compared with the conventional thermoelectric conversion module, and a method for manufacturing the same. <P>SOLUTION: The thermoelectric conversion module 10 includes an insulating layer 1 and a plurality of thermoelectric conversion element pairs 20 formed of P-type thermoelectric conversion elements 21 and N-type thermoelectric conversion elements 22 which are both embedded in the insulating layer 1 with a front surface 2 and a back surface 3 being configured so as to act as a heat transfer surface, wherein the insulating layer has a corrugated plate shape in which a chevron portion 11 and a valley portion 12 are alternately repeated. The plurality of thermoelectric conversion element pairs 20 are arranged on each inclined surface 13 constituting the chevron portion 11 and the valley portion 12 in the insulating layer 1. The plurality of thermoelectric conversion element pairs are electrically connected in the insulating layer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a thermoelectric conversion module and a method for manufacturing the thermoelectric conversion module, and more particularly to a thermoelectric conversion module and a method for manufacturing the thermoelectric conversion module that can increase output per unit area.

  In recent years, the reduction of carbon dioxide has become an important issue in order to prevent global warming, and thermoelectric conversion elements that can directly convert heat into electricity have attracted attention as an effective waste heat utilization technology. ing.

  In one of these thermoelectric conversion elements, a P-type thermoelectric semiconductor, an N-type thermoelectric semiconductor, and a plurality of first accommodation holes formed in a laminate of a plurality of insulating layers having electrical insulation have a P-type. A thermoelectric semiconductor is accommodated, an N-type thermoelectric semiconductor is accommodated in a plurality of second accommodation holes, and a plurality of thermoelectric conversion element pairs formed of the P-type thermoelectric semiconductor and the N-type thermoelectric semiconductor can be arbitrarily selected by a wiring conductor. There has been proposed a thermoelectric conversion module that can be electrically connected to the power supply (see Patent Document 1).

  According to this thermoelectric conversion module, a plurality of thermoelectric conversion element pairs can be arbitrarily electrically connected by wiring conductors provided in the laminate, and the thermoelectric conversion module can be designed with a relatively high degree of freedom. Therefore, the effect of facilitating the realization of the thermoelectric conversion module having various characteristics can be obtained.

By the way, the power generation capability of the thermoelectric conversion element is determined by the thermoelectric conversion characteristics of the material and the temperature difference applied to the element, but the occupation rate of the thermoelectric conversion material (thermoelectric conversion in a plane perpendicular to the direction of the temperature difference occurring in the thermoelectric conversion element) The influence of the ratio of the area occupied by the material portion is also great, and the power generation capacity per unit area of the thermoelectric conversion element can be increased by increasing the occupation ratio of the thermoelectric conversion material.
Japanese Patent No. 3879769

  However, in the case of the above conventional thermoelectric conversion module having a structure in which thermoelectric conversion element pairs are arranged in a flat insulator (laminated body) having a laminated structure, the thermoelectric conversion element pairs are arranged in the laminated body at a high density. Even so, there are restrictions on increasing the arrangement density of the thermoelectric conversion element pairs. That is, even if thermoelectric conversion element pairs are arranged on a flat insulator (laminated body) at a high density in a plane, there is a limit on the plane area for improving the arrangement density.

  The present invention has been made in view of the above circumstances, and it is possible to increase the arrangement density of the thermoelectric conversion element pairs per unit plane area as compared with the conventional thermoelectric conversion module, and the output per unit area can be increased. It is another object of the present invention to provide a thermoelectric conversion module that can be further improved and a method for manufacturing the same.

In order to solve the above problems, the thermoelectric conversion module of the present invention is:
In a thermoelectric conversion module in which a plurality of thermoelectric conversion element pairs, which are pairs of P-type thermoelectric conversion elements and N-type thermoelectric conversion elements, are embedded in an insulating layer, and the front and back surfaces of the insulating layer function as heat transfer surfaces,
The insulating layer has a corrugated shape in which peaks and valleys are alternately repeated.

  In the thermoelectric conversion module of the present invention, it is preferable that a plurality of the thermoelectric conversion element pairs are disposed on each inclined surface constituting the peak and valley of the insulating layer.

  The plurality of thermoelectric conversion element pairs may be electrically connected in a predetermined manner inside the insulating layer.

Moreover, the manufacturing method of the thermoelectric conversion module of the present invention is:
Manufacture of a thermoelectric conversion module in which a plurality of thermoelectric conversion element pairs, which are pairs of P-type thermoelectric conversion elements and N-type thermoelectric conversion elements, are embedded in an insulating layer, and the front and back surfaces of the insulating layer function as heat transfer surfaces A method,
(a) forming a plurality of through holes in the green sheet for the insulating layer;
(b) filling a corresponding through hole among the plurality of through holes with a P-type thermoelectric conversion material or an N-type thermoelectric conversion material;
(c) An unfired laminate having a structure in which a plurality of thermoelectric conversion element pairs are embedded through a step of laminating a plurality of the green sheets, and the thermoelectric conversion element pairs are electrically connected in a predetermined order Forming a body;
(d) forming the green laminate into a corrugated plate.

  Moreover, in this invention, it is desirable to shape | mold the said unbaking laminated body in a corrugated shape by pressing using the metal mold | die with which the peak part and the trough part were formed repeatedly.

  Further, in the step of forming the unfired laminated body, forming the unfired laminated body in which electrodes that are electrically connected to the P-type thermoelectric conversion element and the N-type thermoelectric conversion element are not formed on both sides of the front and back sides. desirable.

  By forming an insulating layer in which a plurality of thermoelectric conversion element pairs composed of P-type thermoelectric conversion elements and N-type thermoelectric conversion elements are embedded into a corrugated plate-like shape in which peaks and troughs are alternately repeated, the insulating layer Compared with the case where has a flat structure, the arrangement density of thermoelectric conversion element pairs per unit plane area can be increased, and the thermoelectric conversion area (area of the heat transfer surface) relative to the plane area can be increased. It becomes possible to increase the ratio. As a result, it is possible to provide a thermoelectric conversion module having a large output per unit area.

  In addition, when a plurality of thermoelectric conversion element pairs are disposed on each inclined surface constituting the peak or valley of the insulating layer, for example, the thermoelectric conversion element pairs are mainly disposed in the peak or valley. Compared with the case where it does, it becomes possible to arrange | position a thermoelectric conversion element reliably at high density, and can make this invention more effective.

  In addition, by using a structure in which a plurality of thermoelectric conversion element pairs are electrically connected in a predetermined manner inside the insulating layer, for example, it is possible to arrange the thermoelectric conversion element pairs in contact with a conductor. It is possible to provide a thermoelectric conversion module with less.

  Further, as in the method of manufacturing the thermoelectric conversion module of the present invention, a plurality of through holes are formed in the green sheet for the insulating layer, and the corresponding through holes are filled with a P-type thermoelectric conversion material and an N-type thermoelectric conversion material. Thereafter, through a step of laminating a plurality of green sheets, an unfired laminate having a structure in which a plurality of thermoelectric conversion element pairs are embedded and each thermoelectric conversion element pair is electrically connected in a predetermined order And forming the green laminate into a corrugated plate, thereby providing a corrugated insulating layer and a plurality of thermoelectric conversion element pairs embedded in the insulating layer. It becomes possible to efficiently manufacture a thermoelectric conversion module that functions as a hot surface.

  Further, in the present invention, the thermoelectric conversion of the present invention can be easily provided with a corrugated insulating layer by pressing a green laminate using a mold in which crests and troughs are repeatedly formed. Modules can be manufactured.

  Further, in forming the unfired laminate, by forming an unfired laminate in which electrodes that are electrically connected to the P-type thermoelectric conversion element and the N-type thermoelectric conversion element are formed on both sides of the front and back, for example, It is possible to obtain a thermoelectric conversion module that can be disposed so as to be in contact with a conductor and has few restrictions on the use environment, which is significant.

  Examples of the present invention will be described below to describe the features of the present invention in more detail.

  FIG. 1 is a plan view schematically showing a configuration of a thermoelectric conversion module according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line AA of FIG.

  As shown in FIGS. 1 and 2, the thermoelectric conversion module 10 includes a plurality of thermoelectric conversion elements including an insulating layer 1 and a P-type thermoelectric conversion element 21 and an N-type thermoelectric conversion element 22 embedded in the insulating layer 1. And a pair 20. Moreover, it is comprised so that the surface 2 and the back surface 3 of the insulating layer 1 may function as a heat transfer surface.

  And the insulating layer 1 is comprised by the corrugated shape by which the peak part 11 and the trough part 12 are repeated alternately. In addition, a plurality of thermoelectric conversion element pairs 20 are disposed on each inclined surface 13 (FIG. 2) constituting the peak portion 11 and the valley portion 12 of the insulating layer 1.

Further, the plurality of thermoelectric conversion element pairs 20 disposed in the insulating layer 1 are electrically connected so as to be connected in series by the electrode 30 inside the insulating layer 1.
Although not particularly shown in FIGS. 1 and 2, internal electrodes are drawn out at predetermined positions on both end surfaces of the insulating layer 1, and external electrodes are disposed so as to be electrically connected to the exposed internal electrodes.

  In the thermoelectric conversion module 10 according to the first embodiment configured as described above, the insulating layer 1 in which a plurality of thermoelectric conversion element pairs 20 including a P-type thermoelectric conversion element 21 and an N-type thermoelectric conversion element 22 are embedded is Since the portion 11 and the trough portion 12 have a corrugated shape that is alternately repeated, the thermoelectric conversion element pairs per unit plane area compared to the case where the insulating layer 1 has a flat structure. As the arrangement ratio of 20 increases, the ratio of the thermoelectric conversion area (area of the heat transfer surface) to the planar area increases. Therefore, a thermoelectric conversion module having a large output per unit area can be obtained.

  Moreover, since the several thermoelectric conversion element pair 20 is arrange | positioned in each inclined surface 13 which comprises the peak part 11 or the trough part 12 of the insulating layer 1, the insulating layer 1 has a flat structure. In addition to the case, it is possible to arrange the thermoelectric conversion element pairs 20 at a high density as compared with the case where the thermoelectric conversion element pairs 20 are mainly arranged in the mountain parts 11 and the valley parts 12. The output can be improved.

  Further, in the case of the thermoelectric conversion module of this embodiment, the thermoelectric conversion element pair 20 is electrically connected so as to be connected in series by the electrode 30 inside the insulating layer 1, and P-type is provided on both sides of the front and back sides. Since the electrodes that are electrically connected to the thermoelectric conversion element 21 and the N-type thermoelectric conversion element 22 are not disposed, for example, the thermoelectric conversion module can be disposed so as to be in contact with the conductor, and the thermoelectric conversion has less restrictions on the use environment. A module 10 can be provided.

Next, a method for manufacturing the thermoelectric conversion module of this embodiment will be described.
In this example, in manufacturing the thermoelectric conversion module, first,
a) Cu powder material as P-type thermoelectric conversion material,
b) Constantan powder material as N-type thermoelectric material,
c) Cu electrode material as an electrode,
d) An insulating ceramic green sheet mainly composed of alumina or the like was prepared as an insulating material constituting the insulating layer.

  A predetermined number of via holes (through holes) for filling the P-type thermoelectric conversion material and the N-type thermoelectric conversion material were formed on the insulating ceramic green sheet by a laser processing method.

Next, a paste prepared using the P-type thermoelectric conversion material powder and a paste prepared using the N-type thermoelectric conversion material powder were filled in predetermined via holes.
In this example, when forming the via holes for filling the P-type and N-type thermoelectric conversion materials, the diameter of the via holes was set to 0.4 mm, and the pitch (center interval) of the via holes was set to 0.7 mm.

Thereafter, an insulating ceramic green sheet filled with a thermoelectric conversion material is laminated to a thickness of 600 μm, and a predetermined circuit pattern is formed on the side facing the laminated insulating ceramic green sheet. After disposing the functional ceramic green sheet, it was pressure-bonded at a predetermined pressure to obtain a green laminate.
In the circuit pattern, a P-type thermoelectric conversion material (element) and an N-type thermoelectric conversion material (element) are connected, and a thermoelectric conversion element pair including a P-type thermoelectric conversion element and an N-type thermoelectric conversion element is connected in series. It functions as an electrode. In this example, the circuit pattern was formed by screen-printing Cu paste on the surface of an insulating ceramic green sheet.

  Next, this laminate was cut into a predetermined size to obtain a flat plate-like unfired laminate. Then, uniaxial pressing (pressing) was performed using a mold having a crest and a trough having an inclined surface with an angle of 30 ° with respect to the perpendicular to the heat transfer direction, as shown in FIGS. Such a corrugated unfired thermoelectric conversion module 10a was produced. The unfired thermoelectric conversion module 10a includes a crest portion 11a and a trough portion 12a having inclined surfaces with an angle of θ = 30 ° with respect to the perpendicular L in the heat transfer direction. Structure of laminated ceramic green sheets) 1a, a plurality of unfired thermoelectric conversion element pairs 20a are arranged on each inclined surface 13a (FIGS. 3 and 4) constituting the peak portion 11a and the valley portion 12a. have.

  Similarly, uniaxial pressure is applied using a die having a crest and a trough having an inclined surface with an angle of 45 ° with respect to the perpendicular to the heat transfer direction, as shown in FIGS. A corrugated unfired thermoelectric conversion module 10a was produced. The unfired thermoelectric conversion module 10a includes a crest portion 11a and a trough portion 12a having inclined surfaces with an angle of θ = 45 ° with respect to the perpendicular line L in the heat transfer direction. Each of the inclined surfaces 13a (FIGS. 5 and 6) constituting the peak portion 11a and the valley portion 12a of the laminated ceramic green sheet 1a has a structure in which a plurality of thermoelectric conversion element pairs 20a are disposed. ing.

  In this example, as the unfired thermoelectric conversion modules shown in FIGS. 3, 4, 5, and 6, the dimensions (plan view dimensions) viewed from a direction parallel to the heat transfer direction are 30 mm × 30 mm. did.

Next, after applying a Cu paste for forming an external electrode so as to be electrically connected to the electrodes (internal electrodes) exposed at both end faces of the unfired thermoelectric conversion module (laminate), firing is performed at 900 to 990 ° C. in a reducing atmosphere. By doing
1) A thermoelectric conversion module (sample 1 of the example) having a crest portion 11 and a trough portion 12 having an inclined surface 13 having an angle of θ = 30 ° with respect to the perpendicular L in the heat transfer direction (see FIGS. 1 and 2). )When,
2) Thermoelectric conversion module having a crest and a trough having an inclined surface with an angle of θ = 45 ° with respect to the perpendicular L in the heat transfer direction (sample 2 of the example (see FIGS. 5 and 6))
Was made.
As described above, the thermoelectric conversion having the corrugated shape of Samples 1 and 2 obtained by firing an unfired thermoelectric conversion module having a plan view size of 30 mm × 30 mm in the unfired stage. The planar view size of the module was approximately 25 mm × 25 mm.

For comparison, as shown in FIGS. 7 and 8, a flat-type (tilt angle 0 °) unfired thermoelectric conversion module (laminated body) (plan view size: 30 mm × 30 mm) 10 a was produced. And after apply | coating the Cu paste for external electrode formation so that it may conduct | electrically_connect with the electrode (internal electrode) exposed to both end surfaces, the planar view dimension is about 25 mm x by baking at 900-990 degreeC in reducing atmosphere. A 25 mm thermoelectric conversion module (sample for comparison) was produced.
7 and 8, the same reference numerals as those in FIGS. 3 to 6 denote the same or corresponding parts.

In addition, the number of via holes (that is, the number of thermoelectric conversion elements) formed in the insulating layer constituting each thermoelectric conversion module (plan view size: 25 mm × 25 mm) manufactured as described above is as follows.
(Sample 1 of Example)
3 in the X direction: 40, Y direction in FIG. 3: 56, 2240 in total (Sample 2 of Example)
X direction of FIG. 5: 40 pieces, Y direction of FIG. 5: 44 pieces, 1760 pieces in total (sample of comparative example)
7 in the X direction: 40, Y direction in FIG. 7: 40, 1600 in total

[Evaluation of characteristics]
A temperature difference was given to the upper and lower surfaces of the samples of Examples 1 and 2 and the sample of the comparative example (thermoelectric conversion module) produced as described above, and the electromotive force (output voltage) and output power were measured. Here, in giving a temperature difference between the upper surface and the lower surface of the thermoelectric conversion module, the high temperature portion was heated by a heater, and the low temperature portion was air-cooled by a fan.
Table 1 shows the measurement results of electromotive force (output voltage) and output power.

  As shown in Table 1, in the case of a sample of a flat type comparative example (thermoelectric conversion module), the size in plan view was 25 mm × 25 mm and the number of thermoelectric elements was 1600, but the insulating layer was shaped like a corrugated plate In the case of the sample 1 processed in Example 1, it was possible to increase the number of thermoelectric elements to 2240 with a plan view size of 25 mm × 25 mm.

Also in the case of the sample 2 of the example, it was possible to increase the number of thermoelectric elements to 1760 with a plan view size of 25 mm × 25 mm.
In the case of Samples 1 and 2 of the example, as shown in Table 1, it was confirmed that the characteristics of the electromotive force (output voltage) and the output electrode were improved as compared with the sample of the comparative example.

  In the above embodiment, the ceramic material is used as the constituent material of the insulating layer. However, a material containing a resin may be used depending on the case.

  The present invention is not limited to the above-described embodiments. The composition of the P-type thermoelectric conversion material and the N-type thermoelectric conversion material, the raw materials thereof, the specific structure of the insulating layer constituting the thermoelectric conversion module, and the insulating layer Various applications and modifications can be made within the scope of the invention with respect to specific conditions for forming into a plate shape, the number of thermoelectric conversion elements embedded in the insulating layer, and the like.

As described above, according to the present invention, the arrangement density of thermoelectric conversion element pairs per unit area can be increased, and the output per unit area can be greatly improved.
Therefore, the present invention can be widely applied to the technical field of thermoelectric conversion modules which are required to increase the arrangement ratio of thermoelectric conversion element pairs per unit area to obtain high output.

It is a perspective view which shows the thermoelectric conversion module concerning Embodiment 1 of this invention. It is the sectional view on the AA line of FIG. It is a perspective view which shows the unbaking thermoelectric conversion module produced at 1 process of the manufacturing method of the thermoelectric conversion module concerning the Example of this invention. FIG. 4 is a sectional view taken along line BB in FIG. 3. It is a perspective view which shows the other unbaking thermoelectric conversion module produced at 1 process of the manufacturing method of the thermoelectric conversion module concerning the Example of this invention. It is CC sectional view taken on the line of FIG. It is a perspective view which shows the non-baking thermoelectric conversion module produced at the manufacturing process of the thermoelectric conversion module concerning a comparative example. It is the DD sectional view taken on the line of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Insulating layer 1a Unbaked insulating layer 2 The surface of an insulating layer 3 The back surface of an insulating layer 10 Thermoelectric conversion module 11 Mountain part 12 Valley part 13 The inclined surface which comprises a mountain part and a valley part 20 Thermoelectric conversion element pair 21 P type thermoelectric conversion element 22 N-type thermoelectric conversion element 30 Electrode 10a Unsintered thermoelectric conversion module 11a Peak part of unsintered thermoelectric conversion module 12a Valley part of unsintered thermoelectric conversion module 13a Slope of unsintered insulating layer 20a not yet Thermoelectric conversion element pair of firing thermoelectric conversion module

Claims (6)

In a thermoelectric conversion module in which a plurality of thermoelectric conversion element pairs, which are pairs of P-type thermoelectric conversion elements and N-type thermoelectric conversion elements, are embedded in an insulating layer, and the front and back surfaces of the insulating layer function as heat transfer surfaces,
The thermoelectric conversion module, wherein the insulating layer has a corrugated shape in which peaks and valleys are alternately repeated.   2. The thermoelectric conversion module according to claim 1, wherein a plurality of the thermoelectric conversion element pairs are disposed on each inclined surface constituting a peak and a valley of the insulating layer.   The thermoelectric conversion module according to claim 1 or 2, wherein the plurality of thermoelectric conversion element pairs are electrically connected in a predetermined manner inside the insulating layer. Manufacture of a thermoelectric conversion module in which a plurality of thermoelectric conversion element pairs, which are pairs of P-type thermoelectric conversion elements and N-type thermoelectric conversion elements, are embedded in an insulating layer, and the front and back surfaces of the insulating layer function as heat transfer surfaces A method,
(a) forming a plurality of through holes in the green sheet for the insulating layer;
(b) filling a corresponding through hole among the plurality of through holes with a P-type thermoelectric conversion material or an N-type thermoelectric conversion material;
(c) An unfired laminate having a structure in which a plurality of thermoelectric conversion element pairs are embedded through a step of laminating a plurality of the green sheets, and the thermoelectric conversion element pairs are electrically connected in a predetermined order Forming a body;
(d) A method of manufacturing a thermoelectric conversion module, comprising: forming the green laminate into a corrugated plate.   5. The thermoelectric conversion module according to claim 4, wherein the green laminate is formed into a corrugated shape by pressing using a mold in which crests and troughs are repeatedly formed. Manufacturing method.   In the step of forming the unsintered laminate, the unsintered laminate is formed on both sides of the front and back sides, and no electrode is provided to be electrically connected to the P-type thermoelectric conversion element and the N-type thermoelectric conversion element. The manufacturing method of the thermoelectric conversion module of Claim 4 or 5.

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