WO2019004429A1 - Thermoelectric conversion module and method for manufacturing thermoelectric conversion module - Google Patents

Abstract

This thermoelectric conversion module (10) is formed by electrically connecting a plurality of thermoelectric conversion elements (11) through first electrode parts (25) disposed on one end sides of the thermoelectric conversion elements (11) and a second electrode part (35) disposed on the other end sides. A first insulating circuit board (20) is disposed on the one end sides of the thermoelectric conversion elements (11), the first insulating circuit board (20) being provided with: a first insulating layer (21), of which at least one surface is formed of alumina; and the first electrode parts (25), which are formed on one surface of the first insulating layer (21) and composed of a fired body of Ag. In addition, a glass component is present in the interface between the first electrode parts (25) and the first insulating layer (21), and the first electrode parts (25) each have a thickness of at least 30 μm and a porosity of less than 10% in at least the region in which the thermoelectric conversion element (11) is disposed.

Description

Thermoelectric conversion module and method of manufacturing thermoelectric conversion module

The present invention relates to a thermoelectric conversion module in which a plurality of thermoelectric conversion elements are electrically connected, and a method of manufacturing the thermoelectric conversion module.
The present application claims priority based on Japanese Patent Application No. 2017-127539 filed on June 29, 2017, and Japanese Patent Application No. 20812-1097 filed on June 26, 2018, on June 29, 2017. , The contents of which are incorporated herein.

The thermoelectric conversion element is an electronic element capable of mutually converting thermal energy and electrical energy by the Seebeck effect or Peltier effect.
The Seebeck effect is a phenomenon in which an electromotive force is generated when a temperature difference is generated between both ends of a thermoelectric conversion element, and thermal energy is converted into electrical energy. The electromotive force generated by the Seebeck effect is determined by the characteristics of the thermoelectric conversion element. In recent years, development of thermoelectric generation utilizing this effect has been brisk.
The Peltier effect is a phenomenon in which when an electrode or the like is formed at both ends of a thermoelectric conversion element to generate a potential difference between the electrodes, a temperature difference occurs at both ends of the thermoelectric conversion element, and electrical energy is converted to thermal energy. An element having such an effect is particularly called a Peltier element, and is used for cooling and temperature control of precision instruments, small refrigerators and the like.

As a thermoelectric conversion module using the above-mentioned thermoelectric conversion element, for example, one having a structure in which an n-type thermoelectric conversion element and a p-type thermoelectric conversion element are alternately connected in series is proposed.
In such a thermoelectric conversion module, heat transfer plates are disposed respectively on one end side and the other end side of a plurality of thermoelectric conversion elements, and the thermoelectric conversion elements are connected in series by the electrode portions disposed on the heat transfer plate. Structure. In addition, as the above-mentioned heat transfer plate, the insulated circuit board provided with the insulating layer and the electrode part may be used.

Then, a temperature difference is caused between the heat transfer plate disposed on one end side of the thermoelectric conversion element and the heat transfer plate disposed on the other end side of the thermoelectric conversion element, whereby electric energy is obtained by the Seebeck effect. Can be generated. Alternatively, by supplying a current to the thermoelectric conversion element, between the heat transfer plate disposed at one end of the thermoelectric conversion element and the heat transfer plate disposed at the other end of the thermoelectric conversion element by the Peltier effect. It is possible to generate a temperature difference.

Here, in the above-mentioned thermoelectric conversion module, in order to improve the thermoelectric conversion efficiency, it is necessary to suppress the electric resistance in the electrode part connected to the thermoelectric conversion element to a low level.
For this reason, conventionally, when joining a thermoelectric conversion element and an electrode part, Ag paste etc. which were especially excellent in conductivity are used. Moreover, an electrode part itself may be formed with Ag paste, and it may join with a thermoelectric conversion element.

However, since the sintered body of Ag paste has a relatively large number of pores, the electrical resistance can not be suppressed sufficiently low. In addition, when using a thermoelectric conversion module in a medium temperature range of 350 ° C. or more, sintering progresses gradually in the sintered body of Ag paste, the structure of the sintered body changes, and the thermoelectric conversion element is generated by the gas existing in the pores. Was likely to deteriorate.
In order to reduce the number of pores by densifying the sintered body of Ag paste, it is conceivable to perform liquid phase sintering by heating to the melting point (960 ° C.) of silver or more. Under such high temperature conditions, thermoelectric conversion is performed at the time of bonding The element may be degraded by heat.

Therefore, for example, in Patent Document 1, a method is proposed in which an electrode portion is formed using a silver solder having a melting point lower than that of silver, and the thermoelectric conversion elements are joined.
Further, in Patent Document 2, in order to suppress deterioration of the thermoelectric conversion element due to the gas in the pores, a dense film is formed by applying a glass solution to the entire outer peripheral surface of the bonding layer and drying in air. A method has been proposed.

JP, 2013-197265, A JP 2012-231025 A

Here, in the method described in Patent Document 1, although silver solder having a melting point lower than that of silver is used, the melting point of the silver solder used is such that the silver solder does not melt even at the operating temperature of the thermoelectric conversion module. For example, 750 to 800 ° C. is preferred (see Patent Document 1, paragraph 0023). When the thermoelectric conversion elements are joined under such relatively high temperature conditions, there is also a possibility that the characteristics of the thermoelectric conversion elements may deteriorate due to the heat at the time of joining.

Further, in the method described in Patent Document 2, bonding is performed at 500 to 800 ° C. using a silver paste, but in this case, there is a possibility that the thermoelectric conversion element may be deteriorated by heat at the time of bonding.

This invention is made in view of the situation mentioned above, and the electric resistance in an electrode part is low, and degradation of the thermoelectric conversion element at the time of joining is suppressed, and the thermoelectric conversion module excellent in the thermoelectric conversion efficiency An object of the present invention is to provide a method of manufacturing a thermoelectric conversion module.

In order to solve the above problems, the thermoelectric conversion module of the present invention comprises a plurality of thermoelectric conversion elements, a first electrode portion disposed on one end side of the thermoelectric conversion elements, and a second on the other end side. A thermoelectric conversion module, comprising: an electrode portion, wherein a plurality of the thermoelectric conversion elements are electrically connected via the first electrode portion and the second electrode portion, wherein one end side of the thermoelectric conversion element A first insulating layer at least one surface of which is made of alumina, and the first electrode portion made of a sintered body of Ag formed on one surface of the first insulating layer. An insulating circuit substrate is disposed, a glass component is present at an interface between the first electrode portion and the first insulating layer, and at least the thermoelectric conversion element is disposed in the first electrode portion. Thickness is 30 μm or more, and the porosity is less than 10%. It is characterized in that there is a.

According to the thermoelectric conversion module of the present invention, the first insulating layer at least one surface of which is made of alumina on one end side of the thermoelectric conversion element, and Ag formed on one surface of the first insulating layer A first insulating circuit substrate including the first electrode portion made of a sintered body is disposed, and the first electrode portion has a thickness of 30 μm or more at least in a region where the thermoelectric conversion element is disposed Since the porosity is less than 10%, the first electrode portion is dense and thick, and the electrical resistance can be reduced. Moreover, since there are few pores, deterioration of the thermoelectric conversion element by the gas of the pores can be suppressed.

Furthermore, since the first electrode portion is a sintered body of Ag paste, the bonding temperature (baking temperature) can be set to a relatively low temperature condition, and deterioration of the thermoelectric conversion element at the time of bonding can be suppressed. . Further, since the first electrode portion itself is made of Ag, it does not melt even at an operating temperature of about 500 to 800 ° C., and can be stably operated.
In the first insulating layer, the surface (one surface) on which the first electrode portion is formed is made of alumina, and the glass component is present at the interface between the first electrode portion and the first insulating layer. Since the glass component and the alumina react with each other, the first electrode portion and the first insulating layer are strongly bonded to each other, and the bonding reliability is excellent.

Here, in the thermoelectric conversion module according to the present invention, the first electrode portion is composed of a glass-containing region and a non-glass-containing region from the first insulating layer side in the stacking direction, and the glass-containing region is stacked When the thickness in the direction is Tg, and the thickness in the lamination direction of the non-glass-containing region is Ta, it is preferable that Ta / (Ta + Tg) is more than 0 and not more than 0.5.
In this case, the first electrode portion has a structure in which the glass-containing region and the non-glass-containing region are stacked, and the thickness in the stacking direction of the glass-containing region is Tg, and the stacking direction of the non-glass-containing region When Ta has a thickness of Ta, Ta / (Ta + Tg) is limited to 0.5 or less, so it is possible to suppress the occurrence of peeling at the interface between the glass-containing region and the non-glass-containing region. Moreover, since Ta / (Ta + Tg) is more than 0, no glass component exists in the bonding surface with the thermoelectric conversion element, and the bonding property between the thermoelectric conversion element and the first electrode portion is improved. Is possible.

In the thermoelectric conversion module according to the present invention, the second insulating layer at least one surface of which is made of alumina and the other surface of the second insulating layer are formed on the other end side of the thermoelectric conversion element. And a second insulating circuit substrate including the second electrode portion made of a sintered body of Ag, and a glass component is present at an interface between the second electrode portion and the second insulating layer. The second electrode portion may have a thickness of 30 μm or more and a porosity of less than 10% at least in a region where the thermoelectric conversion element is disposed.

In this case, the second insulating layer at least one surface of which is made of alumina on the other end side of the thermoelectric conversion element, and the sintered body of Ag formed on one surface of the second insulating layer And a second insulating circuit substrate having two electrode portions, and the second electrode portion of the second insulating circuit substrate also has a thickness at least in a region where the thermoelectric conversion element is disposed. Since the porosity is 30 μm or more and the porosity is less than 10%, the second electrode portion is formed dense and thick, and the electrical resistance becomes low. Moreover, since there are few pores, deterioration of the thermoelectric conversion element by the gas of the pores can be suppressed.

Furthermore, since the second electrode portion is a sintered body of Ag paste, the bonding temperature (baking temperature) can be set to a relatively low temperature condition, and deterioration of the thermoelectric conversion element at the time of bonding can be suppressed. . Further, since the second electrode portion itself is made of Ag, it does not melt even at an operating temperature of about 500 to 800 ° C., and can be stably operated.
In the second insulating layer, the surface (one surface) on which the second electrode portion is formed is made of alumina, and the glass component is present at the interface between the second electrode portion and the second insulating layer. Since the glass component and the alumina react with each other, the second electrode portion and the second insulating layer are strongly bonded to each other, and the bonding reliability is excellent.

Here, in the thermoelectric conversion module according to the present invention, the second electrode portion is composed of a glass-containing region and a non-glass-containing region from the second insulating layer side in the stacking direction, and the glass-containing region is stacked When the thickness in the direction is Tg, and the thickness in the laminating direction of the non-glass-containing region is Ta, it is preferable that Ta / (Ta + Tg) is more than 0 and 0.5 or less.
In this case, the second electrode portion has a structure in which the glass-containing region and the non-glass-containing region are stacked, and the thickness in the stacking direction of the glass-containing region is Tg, and the stacking direction of the non-glass-containing region When Ta has a thickness of Ta, Ta / (Ta + Tg) is limited to 0.5 or less, so it is possible to suppress the occurrence of peeling at the interface between the glass-containing region and the non-glass-containing region. Moreover, since Ta / (Ta + Tg) is more than 0, no glass component exists in the bonding surface with the thermoelectric conversion element, and the bonding property between the thermoelectric conversion element and the second electrode portion is improved. Is possible.

The method for manufacturing a thermoelectric conversion module according to the present invention comprises a plurality of thermoelectric conversion elements, a first electrode portion disposed on one end side of the thermoelectric conversion elements, and a second electrode portion disposed on the other end side. It is a manufacturing method of the thermoelectric conversion module which has a plurality of said thermoelectric conversion elements electrically connected via said 1st electrode part and said 2nd electrode part, and said thermoelectric conversion module is said thermoelectric conversion A first insulating layer, at least one surface of which is made of alumina, on one end side of the device, and the first electrode portion made of a sintered body of Ag formed on one surface of the first insulating layer A first insulating circuit substrate is disposed, and an Ag paste application step of applying an Ag paste containing Ag to a thickness of 30 μm or more on one surface of the first insulating layer, and firing the Ag paste Firing step to form a first electrode portion, Laminating the first insulating layer on one end side of the thermoelectric conversion element via the first electrode portion, pressurizing the heating element and the first insulating layer in the laminating direction and heating the same; A thermoelectric conversion element bonding step of bonding a thermoelectric conversion element, and in the Ag paste application step, a glass-containing Ag paste is applied to at least the lowermost layer in contact with the first insulating layer, and the thermoelectric conversion element In the bonding step, the pressure load is in the range of 20 MPa to 50 MPa, the heating temperature is 300 ° C. or higher, and the first electrode portion has a thickness at least in the region where the thermoelectric conversion element is disposed. It is characterized in that it is 30 μm or more and the porosity is less than 10%.

According to the method of manufacturing a thermoelectric conversion module configured as described above, in the step of bonding the thermoelectric conversion element, the heating load is set to 300 ° C. or higher, within a range of 20 MPa or more and 50 MPa or less. In at least a region of the first electrode portion where the thermoelectric conversion element is disposed, the thickness can be 30 μm or more and the porosity can be less than 10%. Moreover, since it is set as comparatively low temperature conditions, deterioration of the thermoelectric conversion element at the time of joining (at the time of baking) can be suppressed.
Further, in the Ag paste application step, the glass-containing Ag paste is applied to at least the lowermost layer in contact with the first insulating layer, so that the glass component of the glass-containing Ag paste and alumina react with each other. The insulating layer and the first electrode portion can be reliably bonded.

Here, in the method of manufacturing a thermoelectric conversion module according to the present invention, in the Ag paste applying step, an Ag paste containing no glass component is applied to the uppermost layer of the first electrode portion in contact with the thermoelectric conversion element. It may be
In this case, since the Ag paste containing no glass component is applied to the uppermost layer in contact with the thermoelectric conversion element, a glass non-containing region containing no glass component is provided on the thermoelectric conversion element side of the first electrode portion. It becomes possible to form reliably and to improve the bondability of the 1st electrode part and the thermoelectric conversion element.

In the method of manufacturing a thermoelectric conversion module according to the present invention, the thermoelectric conversion element may be disposed after disposing an Ag bonding material on the first electrode portion in the laminating step.
In this case, after the Ag bonding material is disposed on the first electrode portion, the thermoelectric conversion element is disposed, and then the thermoelectric conversion element is joined under the above-described conditions. The Ag bonding material applied on the electrode portion can also be densified to have a porosity of less than 10%. Moreover, it becomes possible to improve the bondability of the said 1st electrode part and the said thermoelectric conversion element.

Further, in the method of manufacturing a thermoelectric conversion module according to the present invention, the thermoelectric conversion module includes a first insulating layer having at least one surface made of alumina on one end side of the thermoelectric conversion element, and the first insulating layer. A first insulating circuit board comprising the first electrode portion made of a sintered body of Ag formed on one side of the first surface, and at least one side of the thermoelectric conversion element is alumina on the other side of the thermoelectric conversion element A second insulating circuit substrate comprising a second insulating layer constituted by the second insulating layer and the second electrode portion made of a sintered body of Ag formed on one surface of the second insulating layer In the Ag paste application step, an Ag paste containing Ag is applied to one surface of the first insulating layer and the second insulating layer with a thickness of 30 μm or more, and at least the first insulating layer and the first insulating layer 2 At the lowest layer in contact with the insulating layer A glass-containing Ag paste is applied, and in the firing step, the Ag paste is fired to form the first electrode portion and the second electrode portion, and in the laminating step, the first electrode portion and the second electrode portion are formed on one end side of the thermoelectric conversion element. While laminating the first insulating layer through the first electrode portion, laminating the second insulating layer through the second electrode portion on the other end side of the thermoelectric conversion element, and in the thermoelectric conversion element bonding step The first insulating layer, the thermoelectric conversion element, and the second insulating layer are pressurized and heated in the stacking direction, and the first electrode portion and the thermoelectric conversion element, and the thermoelectric conversion element and the second The electrode parts are joined, and in the thermoelectric conversion element bonding step, the pressure load is in the range of 20 MPa to 50 MPa, the heating temperature is 300 ° C. or more, and the first electrode part and the second electrode part are , At least the thermoelectric In a region where the conversion element is disposed, the thickness may be 30 μm or more, and the porosity may be less than 10%.

In this case, also in the second electrode portion of the second insulating circuit board disposed on the other end side of the thermoelectric conversion element, the thickness is at least 30 μm and at least in the region where the thermoelectric conversion element is disposed. The porosity can be less than 10%. Moreover, since it is set as comparatively low temperature conditions, deterioration of the thermoelectric conversion element at the time of joining (at the time of baking) can be suppressed.
Further, in the Ag paste application step, the glass-containing Ag paste is applied to at least the lowermost layer in contact with the first insulating layer and the second insulating layer, so that the glass component of the glass-containing Ag paste reacts with alumina. Thus, the first insulating layer and the first electrode portion, and the second insulating layer and the second electrode portion can be reliably joined.

Furthermore, in the method of manufacturing a thermoelectric conversion module according to the present invention, in the Ag paste application step, an Ag paste containing no glass component is applied to the uppermost layer of the second electrode portion in contact with the thermoelectric conversion element. It is also good.
In this case, since the Ag paste containing no glass component is applied to the uppermost layer of the second electrode portion in contact with the thermoelectric conversion element, the glass component is applied to the thermoelectric conversion element side of the second electrode portion. It is possible to reliably form the non-glass-containing region which is not included, and to improve the bonding property between the first electrode portion and the thermoelectric conversion element.

In the method of manufacturing a thermoelectric conversion module according to the present invention, the thermoelectric conversion element may be disposed after disposing an Ag bonding material on the second electrode portion.
In this case, after the Ag bonding material is disposed on the second electrode portion, the thermoelectric conversion element is disposed, and thereafter, the thermoelectric conversion element is joined under the above-described conditions. The Ag bonding material applied on the electrode portion can also be densified to have a porosity of less than 10%. Moreover, it becomes possible to improve the bondability of the said 2nd electrode part and the said thermoelectric conversion element.

According to the present invention, the present invention provides a thermoelectric conversion module which has low electric resistance in the electrode portion and suppresses deterioration of the thermoelectric conversion element at the time of bonding, and which has excellent thermoelectric conversion efficiency, and a method of manufacturing the thermoelectric conversion module. can do.

It is a schematic explanatory drawing of the thermoelectric conversion module which is embodiment of this invention. It is a schematic explanatory drawing which shows the glass content area | region and the non-glass containing area | region in a 1st electrode part and a 2nd electrode part. It is a flowchart which shows the manufacturing method of the thermoelectric conversion module which is embodiment of this invention. It is a schematic explanatory drawing of the manufacturing method of the thermoelectric conversion module which is embodiment of this invention. It is a schematic explanatory drawing of the thermoelectric conversion module which is other embodiment of this invention.

Hereinafter, embodiments of the present invention will be described with reference to the attached drawings. Each embodiment shown below is concretely described in order to understand the meaning of the invention better, and does not limit the present invention unless otherwise specified. Further, in the drawings used in the following description, for the sake of easy understanding of the features of the present invention, the main parts may be enlarged for convenience, and the dimensional ratio of each component may be the same as the actual one. Not necessarily.

As shown in FIG. 1, the thermoelectric conversion module 10 according to the present embodiment is arranged on a plurality of columnar thermoelectric conversion elements 11 and one end side (lower side in FIG. 1) of the thermoelectric conversion elements 11 in the length direction. A first heat transfer plate 20 is provided, and a second heat transfer plate 30 disposed on the other end side (upper side in FIG. 1) of the thermoelectric conversion elements 11 in the longitudinal direction.
Here, as shown in FIG. 1, the first electrode portion 25 is formed on the first heat transfer plate 20 disposed on one end side of the thermoelectric conversion element 11, and disposed on the other end side of the thermoelectric conversion element 11. A second electrode portion 35 is formed on the second heat transfer plate 30. The plurality of columnar thermoelectric conversion elements 11 are electrically connected in series by the first electrode portion 25 and the second electrode portion 35. It is done.

The first heat transfer plate 20 includes a first insulating layer 21 and a first electrode portion 25 formed on one surface (upper surface in FIG. 1) of the first insulating layer 21. It consists of
Here, in the first insulating layer 21 of the first heat transfer plate 20 (first insulating circuit board), at least the surface (one surface) on which the first electrode portion 25 is formed is made of alumina. In the present embodiment, the entire first insulating layer 21 is made of alumina.
In the first insulating layer 21, the interface with the silver paste may be alumina, and for example, a substrate whose surface is alumina by oxidizing aluminum nitride may be used as the first insulating layer 21. The thickness of alumina may be in the range of 1 μm to 2000 μm.
The thickness of the first insulating layer 21 may be in the range of 100 μm to 2000 μm.

The first electrode portion 25 is formed of a sintered body of Ag, and the lowermost layer in contact with at least one surface of the first insulating layer 21 made of alumina is formed of a sintered body of a glass-containing Ag paste containing a glass component. It is done. In the present embodiment, the entire first electrode portion 25 is formed of a sintered body of glass-containing Ag paste. Further, the first electrode portion 25 is formed in a pattern on one surface (upper surface in FIG. 1) of the first insulating layer 21.

And in this 1st electrode part 25, thickness is 30 micrometers or more and porosity P is less than 10% in the area | region where the thermoelectric conversion element 11 is arrange | positioned at least.
It is preferable that the upper limit of the thickness of the area | region where the thermoelectric conversion element 11 of the 1st electrode part 25 is arrange | positioned at least is 70 micrometers. In addition, the porosity P can be reduced to 0%.
The porosity P of the first electrode portion 25 can be calculated as follows. After mechanically polishing the cross section of the first electrode unit 25, Ar ion etching (Cross section polisher SM-09010 manufactured by Nippon Denshi Co., Ltd.) is performed, and cross sectional observation is performed using a laser microscope (VKX-200 manufactured by Keyence Inc.) did. Then, the obtained image was subjected to a binarization treatment, and the white portion was made Ag, and the black portion was made pores. The area of the black part was determined from the binarized image, and the porosity was calculated by the following equation. The porosity of each cross section was arithmetically averaged to determine the porosity P of the first electrode portion 25.
Porosity P = black area (pores) area / observed area of the first electrode portion 25

Here, in the first electrode portion 25, as described above, the lowermost layer in contact with at least one surface of the first insulating layer 21 made of alumina is formed of a sintered body of glass-containing Ag paste containing a glass component. Thus, a glass component is present at the interface between the first insulating layer 21 and the first electrode portion 25.
In the present embodiment, the entire first electrode portion 25 is formed of a sintered body of glass-containing Ag paste, and glass particles are dispersed inside the first electrode portion 25. The glass particles are present at the interface between the first insulating layer 21 (alumina) and the first electrode portion 25. Further, part of the glass component is intruding into the first insulating layer 21 (alumina) side.

Further, in the present embodiment, as shown in FIG. 2, the first electrode portion 25 does not have a glass component and a glass containing region 25A having a glass component from the side of the first insulating layer 21 in the stacking direction. When the thickness in the stacking direction of the glass-containing region 25A is Tg, and the thickness in the stacking direction of the non-glass-containing region 25B is Ta, Ta / (Ta + Tg) exceeds 0, 0 It is preferable that it is less than or equal to .5. Ta / (Ta + Tg) is more preferably in the range of 0.17 or more and 0.83 or less, and still more preferably in the range of 0.33 or more and 0.67 or less.
As shown in FIG. 2, the thickness Tg of the glass-containing region 25 </ b> A in the stacking direction is the thickness from the first insulating layer 21 to the glass particles 27 located at the farthest position in the stacking direction.
The thickness Ta of the non-glass-containing region 25B in the stacking direction is a value obtained by subtracting the thickness Tg of the glass-containing region 25A in the stacking direction from the thickness of the first electrode portion 25.

The second heat transfer plate 30 includes a second insulating layer 31 and a second electrode portion 35 formed on one surface (a lower surface in FIG. 1) of the second insulating layer 31. It consists of
Here, the second insulating layer 31 of the second heat transfer plate 30 (second insulating circuit substrate) can have the same configuration as that of the first insulating layer 21 described above.

The second electrode portion 35 is formed of a sintered body of Ag, and the lowermost layer in contact with at least one surface of the second insulating layer 31 made of alumina is formed of a sintered body of a glass-containing Ag paste containing a glass component. It is done. In the present embodiment, the entire second electrode portion 35 is formed of a sintered body of glass-containing Ag paste. In addition, the second electrode portion 35 is formed in a pattern on one surface (the lower surface in FIG. 1) of the second insulating layer 31.

And in the 2nd electrode part 35, thickness is 30 micrometers or more and porosity P is less than 10% at least in a field where thermoelectric conversion element 11 is arranged.
It is preferable that the upper limit of the thickness of the area | region where the thermoelectric conversion element 11 of the 2nd electrode part 35 is arrange | positioned at least is 70 micrometers or less. In addition, the porosity P can be reduced to 0%.
The porosity P of the second electrode portion 35 can be calculated by the same method as that of the first electrode portion 25.

Here, in the second electrode portion 35, as described above, the lowermost layer in contact with at least one surface of the second insulating layer 31 made of alumina is formed of a sintered body of glass-containing Ag paste containing a glass component. Thus, a glass component is present at the interface between the second insulating layer 31 and the second electrode portion 35.
In the present embodiment, the entire second electrode portion 35 is formed of a sintered body of glass-containing Ag paste, and glass particles are present inside the second electrode portion 35. The glass particles are present at the interface between the second insulating layer 31 (alumina) and the first electrode portion 25. Further, part of the glass component is intruding into the second insulating layer 31 (alumina) side.

Further, in the present embodiment, as shown in FIG. 2, the second electrode portion 35 has a glass-containing region 35A having a glass component and a glass having no glass component from the second insulating layer 31 side in the stacking direction. When the thickness in the stacking direction of the glass-containing region 35A is Tg and the thickness in the stacking direction of the non-glass-containing region 35B is Ta, Ta / (Ta + Tg) exceeds 0, 0 It is preferable that it is less than or equal to .5. Ta / (Ta + Tg) is more preferably in the range of 0.17 or more and 0.83 or less, and still more preferably in the range of 0.33 or more and 0.67 or less.
As shown in FIG. 2, the thickness Tg of the glass-containing region 35 </ b> A in the stacking direction is the thickness from the second insulating layer 31 to the glass particles 37 located farthest in the stacking direction.
Further, the thickness Ta of the non-glass-containing region 35B in the stacking direction is a value obtained by subtracting the thickness Tg of the glass-containing region 35A in the stacking direction from the thickness of the second electrode portion 35.

The thermoelectric conversion element 11 has an n-type thermoelectric conversion element 11a and a p-type thermoelectric conversion element 11b, and these n-type thermoelectric conversion elements 11a and p-type thermoelectric conversion elements 11b are alternately arranged.
Metallized layers (not shown) are respectively formed on one end surface and the other end surface of the thermoelectric conversion element 11. As the metallized layer, it is possible to use, for example, nickel, silver, cobalt, tungsten, molybdenum or the like, or a non-woven fabric or the like made of these metal fibers. The outermost surface of the metallized layer (the bonding surface with the first electrode portion 25 and the second electrode portion 35) is preferably made of Au or Ag.

The n-type thermoelectric conversion element 11a and the p-type thermoelectric conversion element 11b are, for example, sintered bodies of tellurium compound, skutterudite, filled skutterudite, Heusler, half-Heusler, clathrate, silicide, oxide, silicon germanium, etc. It is configured.
As a material of the n-type thermoelectric conversion element 11 a, for example, Bi ₂ Te ₃ , PbTe, La ₃ Te ₄ , CoSb ₃ , FeVAl, ZrNiSn, Ba ₈ Al ₁₆ Si ₃₀ , Mg ₂ Si, FeSi ₂ , SrTiO ₃ , CaMnO ₃ , ZnO, SiGe and the like are used.
Moreover, as a material of the p-type thermoelectric conversion element 11b, for example, Bi ₂ Te ₃ , Sb ₂ Te ₃ , PbTe, TAGS (= Ag-Sb-Ge-Te), Zn ₄ Sb ₃ , CoSb ₃ , CeFe ₄ Sb ₁₂ Yb ₁₄ MnSb ₁₁ , FeVAl, MnSi _1.73 , FeSi ₂ , NaxCoO ₂ , Ca ₃ Co ₄ O ₇ , Bi ₂ Sr ₂ Co ₂ O ₇ , SiGe or the like is used.
There are a compound which can take both n-type and p-type depending on a dopant and a compound having only n-type or p-type property.

Next, a method of manufacturing the above-described thermoelectric conversion module 10 according to the present embodiment will be described with reference to FIGS. 3 and 4.

(Ag paste application step S01)
First, an Ag paste containing Ag is applied to one surface of the first insulating layer 21 and one surface of the second insulating layer 31 to a thickness exceeding 30 μm. The coating thickness is preferably 40 μm or more. Here, the coating method is not particularly limited, and various means such as a screen printing method, an offset printing method, and a photosensitive process can be adopted. At this time, a glass-containing Ag paste having a glass component is applied to the lowermost layer in contact with at least the first insulating layer 21 and the second insulating layer 31.
Here, the application and drying of the paste may be repeatedly performed in order to make the application thickness exceed 30 μm. In this case, the glass-containing paste may be applied to the lowermost layer in contact with the first insulating layer 21 and the second insulating layer 31, and thereafter, an Ag paste containing no glass component may be applied.

Moreover, you may apply | coat Ag paste which does not contain a glass component in the uppermost layer which contact | connects the thermoelectric conversion element 11. As shown in FIG.
Furthermore, the first glass-containing paste is applied to the lowermost layer in contact with the first insulating layer 21 and the second insulating layer 31, and the content of glass is smaller on the first glass-containing paste than in the first glass-containing paste. A second glass-containing paste may be applied, and an Ag paste not containing a glass component may be applied on the second glass-containing paste.
In addition, when apply | coating a paste in multiple times, after drying the applied paste, it is preferable to apply the following paste. Furthermore, after firing the applied paste once, the next paste may be applied.

Here, in the case of applying an Ag paste containing no glass component to the uppermost layer in contact with the thermoelectric conversion element 11, the thickness of the non-glass-containing regions 25B and 35B is controlled by adjusting the application thickness of the Ag paste. Accordingly, it is preferable to set the above-mentioned Ta / (Ta + Tg) in the range of more than 0 and 0.5 or less.

In the present embodiment, as shown in FIG. 4A, the glass-containing Ag pastes 45 and 55 are respectively applied to one surface of the first insulating layer 21 and one surface of the second insulating layer 31. It is applied at a thickness of more than 30 μm.
Here, in the present embodiment, a glass-containing Ag paste for forming the first electrode unit 25 and the second electrode unit 35 will be described.

As the glass-containing Ag paste, a paste containing silver as a conductive metal as a main component and containing a glass frit for bonding to a ceramic substrate can be used. For example, LTCC manufactured by Daiken Kagaku Kogyo Co., Ltd. For example, it is possible to use a paste for glass, a glass-containing Ag paste such as TDPAG-TS1002 manufactured by AS ONE Corporation, or DD-1240D manufactured by Kyoto Elex. In this embodiment, DD-1240D manufactured by Kyoto Elex Co., Ltd. is used.

(Firing step S02)
Next, heat treatment is performed in a state in which Ag paste (glass-containing Ag paste 45, 55) is applied to one surface of the first insulating layer 21 and one surface of the second insulating layer 31, respectively. The paste (glass-containing Ag paste 45, 55) is fired. In addition, you may implement the drying process which removes the solvent of Ag paste (glass containing Ag paste 45, 55) before baking. Thereby, the 1st electrode part 25 and the 2nd electrode part 35 which are shown in Drawing 4 (b) are formed.
In the firing step S02, firing is preferably performed under the conditions of an air atmosphere, a heating temperature of 800 ° C. to 900 ° C., and a holding time of 10 minutes to 60 minutes at the heating temperature.
Note that annealing may be performed after the firing step S02. By performing the annealing, the first electrode portion 25 and the second electrode portion 35 can be made into a more dense fired body. The annealing conditions may be 700 to 850 ° C. for 1 to 24 hours.

(Lamination process S03)
Next, the first insulating layer 21 is disposed on one end side (the lower side in FIG. 4C) of the thermoelectric conversion element 11 via the first electrode portion 25 and the other end side of the thermoelectric conversion element 11 (FIG. The second insulating layer 31 is disposed on the upper side in 4 (c) via the second electrode portion 35.

(Thermoelectric conversion element bonding step S04)
Next, the first insulating layer 21, the thermoelectric conversion element 11, and the second insulating layer 31 are pressurized and heated in the stacking direction, and the thermoelectric conversion element 11 and the first electrode portion 25, and the thermoelectric conversion element 11 and the first The two electrode parts 35 are joined. In the present embodiment, the thermoelectric conversion element 11 is bonded to the first electrode 25 and the second electrode 35 by solid phase diffusion bonding.
Then, in a region where at least the thermoelectric conversion element 11 of the first electrode portion 25 is disposed, the thickness is 30 μm or more, and the porosity P is less than 10%. Similarly, in at least a region of the second electrode portion 35 where the thermoelectric conversion element 11 is disposed, the thickness is 30 μm or more, and the porosity P is less than 10%.

In this thermoelectric conversion element bonding step S04, the heating load is set to 300 ° C. or higher in a pressure load range of 20 MPa to 50 MPa. Further, in the present embodiment, the atmosphere is set to a vacuum atmosphere within the range of 5 minutes to 60 minutes at the above-mentioned heating temperature.

Here, when the pressure load in the thermoelectric conversion element bonding step S04 is less than 20 MPa, there is a possibility that the porosity P of the first electrode portion 25 and the second electrode portion 35 can not be less than 10%. On the other hand, when the pressure load in the thermoelectric conversion element bonding step S04 exceeds 50 MPa, cracking may occur in the thermoelectric conversion element 11 and the first insulating layer 21 and the second insulating layer 31 made of alumina.
For this reason, in the present embodiment, the pressure load in the thermoelectric conversion element bonding step S04 is set in the range of 20 MPa or more and 50 MPa or less.
In addition, in order to make porosity P of the 1st electrode part 25 and the 2nd electrode part 35 certainly less than 10%, it is preferable to make the minimum of the pressurization load in thermoelectric conversion element joining process S04 into 20 MPa or more, It is more preferable to set it as 30 MPa or more. On the other hand, in order to reliably suppress the occurrence of cracks in the thermoelectric conversion element 11 and the first insulating layer 21 and the second insulating layer 31 made of alumina, the upper limit of the pressing load in the thermoelectric conversion element bonding step S04 is 50 MPa or less It is preferable to set the pressure to 40 MPa or less.

In addition, if the heating temperature in the thermoelectric conversion element bonding step S04 is less than 300 ° C., there is a possibility that the thermoelectric conversion element 11 can not be bonded to the first electrode portion 25 and the second electrode portion 35.
Moreover, it is preferable that the heating temperature in thermoelectric conversion element joining process S04 shall be 500 degrees C or less. If the temperature exceeds 500 ° C., the thermoelectric conversion element 11 may be thermally decomposed to deteriorate the characteristics.
In order to ensure that the thermoelectric conversion element 11 is joined to the first electrode portion 25 and the second electrode portion 35, the lower limit of the heating temperature in the thermoelectric conversion element bonding step S04 is preferably 350 ° C. or more. On the other hand, in order to reliably suppress the thermal decomposition of the thermoelectric conversion element 11, it is more preferable to set the upper limit of the heating temperature in the thermoelectric conversion element bonding step S04 to 400 ° C. or less.

As described above, the thermoelectric conversion module 10 according to this embodiment shown in FIG. 4D is manufactured.
In the thermoelectric conversion module 10 according to this embodiment obtained in this manner, for example, the first heat transfer plate 20 side is used as a low temperature portion, and the second heat transfer plate 30 side is used as a high temperature portion. Conversion with electrical energy is performed.

In the thermoelectric conversion module 10 according to the present embodiment configured as described above, at one end side of the thermoelectric conversion element 11, the first insulating layer 21 at least one surface of which is made of alumina, and the first insulating layer 21. A first heat transfer plate 20 (first insulating circuit board) including a first electrode portion 25 formed of a sintered body of Ag formed on one surface of the insulating layer 21 is disposed, and the first electrode portion 25 is provided. Since the thickness is 30 μm or more and the porosity P is less than 10% at least in the region where the thermoelectric conversion element 11 is disposed, the first electrode portion 25 is dense and thick, and the electric Resistance is lowered. Moreover, since there are few pores, deterioration of the thermoelectric conversion element 11 by the gas of the pores can be suppressed.

Furthermore, since the first electrode portion 25 is a fired body of Ag paste (glass-containing Ag paste 45), the bonding temperature (baking temperature) can be set to a relatively low temperature condition of 400 ° C. or less, for example. Deterioration of the thermoelectric conversion element 11 at the time can be suppressed.
Furthermore, since a brazing material such as silver brazing is not used at the time of joining, no liquid phase is generated, and height variations occurring when using thermoelectric conversion elements having different thermal expansion coefficients for P-type and N-type, etc. It is possible to suppress.
Further, since the first electrode portion 25 itself is made of Ag, it does not melt even at an operating temperature of about 500 to 800 ° C., and can be stably operated.
Furthermore, the surface of the first insulating layer 21 on which the first electrode portion 25 is formed is made of alumina, and a glass component is present at the interface between the first electrode portion 25 and the first insulating layer 21. Therefore, the reaction between the glass component and the alumina causes the first electrode portion 25 and the first insulating layer 21 to be strongly bonded, and the bonding reliability is excellent.

Furthermore, in the present embodiment, the first electrode portion 25 has a structure in which the glass-containing region and the non-glass-containing region are stacked, and the thickness of the glass-containing region in the stacking direction is Tg. When Ta / (Ta + Tg) is limited to 0.5 or less when the thickness in the laminating direction is Ta, the occurrence of peeling at the interface between the glass-containing region and the non-glass-containing region is suppressed It becomes possible.
Further, if Ta / (Ta + Tg) exceeds 0, no glass component is present on the bonding surface with the thermoelectric conversion element 11, and the bonding reliability between the thermoelectric conversion element 11 and the first electrode portion 25 is improved. Is possible. Furthermore, in this case, since the glass component is not present on the surface of the first electrode portion 25, it is possible to improve the bonding reliability.

Moreover, in the present embodiment, the second insulating circuit board is disposed on the other end side of the thermoelectric conversion element 11, and at least the thermoelectric conversion element 11 is disposed also on the second electrode portion 35 of the second insulating circuit board. In the above region, the thickness is 30 μm or more, and the porosity P is less than 10%. Therefore, the second electrode portion 35 is formed dense and thick, and the electric resistance becomes low. Moreover, since there are few pores, deterioration of the thermoelectric conversion element 11 by the gas of the pores can be suppressed.

Furthermore, since the second electrode portion 35 is a fired body of Ag paste (glass-containing Ag paste 55), the bonding temperature (baking temperature) can be set to a relatively low temperature condition of 400 ° C. or less, for example. Deterioration of the thermoelectric conversion element 11 at the time can be suppressed. Further, since the second electrode portion 35 itself is made of Ag, it does not melt even at an operating temperature of about 500 to 800 ° C., and can be stably operated.
Further, the surface of the second insulating layer 31 on which the second electrode portion 35 is formed is made of alumina, and a glass component is present at the interface between the second insulating layer 31 and the second electrode portion 35. Since the glass component and the alumina react with each other, the second electrode portion 35 and the second insulating layer 31 are firmly bonded to each other, and the bonding reliability is excellent.

Furthermore, in the present embodiment, the second electrode portion 35 has a structure in which the glass-containing region and the non-glass-containing region are stacked, and the thickness of the glass-containing region in the stacking direction is Tg. When Ta / (Ta + Tg) is limited to 0.5 or less when the thickness in the laminating direction is Ta, the occurrence of peeling at the interface between the glass-containing region and the non-glass-containing region is suppressed It becomes possible.
In addition, if Ta / (Ta + Tg) exceeds 0, no glass component exists on the bonding surface with the thermoelectric conversion element 11, and the bonding reliability between the thermoelectric conversion element 11 and the second electrode portion 35 is improved. Is possible. Furthermore, in this case, since no glass component is present on the surface of the second electrode portion 35, it is possible to improve the bonding reliability.

According to the method of manufacturing the thermoelectric conversion module of the present embodiment, in the thermoelectric conversion element bonding step S04, the heating load is set to 300 ° C. or higher, within the range of 20 MPa to 50 MPa. The thickness can be 30 μm or more and the porosity P can be less than 10% in a region where at least the thermoelectric conversion element 11 of the electrode 25 and the second electrode 35 is disposed. Moreover, since it is set as comparatively low temperature conditions, deterioration of the thermoelectric conversion element 11 at the time of joining can be suppressed.
In addition, since the glass-containing Ag paste is applied to one surface of the first insulating layer 21 and the second insulating layer 31 and fired, the glass component and the alumina react with each other. The 1st insulating layer 21 and the 1st electrode part 25 and the 2nd insulating layer 31 and the 2nd electrode part 35 can be joined certainly.

As mentioned above, although one Embodiment of this invention was described, this invention is not limited to this, It can change suitably in the range which does not deviate from the technical idea of the invention.

For example, in the present embodiment, the thermoelectric conversion element 11 is directly stacked on the first electrode unit 25 and the second electrode unit 35 in the stacking step S03 and described as solid phase diffusion bonding, but the present invention is limited thereto Alternatively, after the Ag bonding material is disposed on the first electrode portion 25 and the second electrode portion 35, the thermoelectric conversion element 11 may be disposed and bonded using the Ag bonding material.
In this case, as shown in FIG. 5, the first bonding layer 27 is formed between the first electrode portion 25 and the thermoelectric conversion element 11, and the second bonding layer is formed between the second electrode portion 35 and the thermoelectric conversion element 11. 37 are formed. In the thermoelectric conversion element bonding step S04, since the pressure heating process is performed under the above-described conditions, the porosity is less than 10% also in the first bonding layer 27 and the second bonding layer 37.

Further, although the second heat transfer plate 30 is provided with the second insulated circuit board on the other end side of the thermoelectric conversion element 11 in the present embodiment, the present invention is not limited to this. For example, The second heat transfer plate may be configured by disposing the second electrode portion on the other end side of the conversion element 11 and stacking the insulating substrate and pressing the insulating substrate in the stacking direction.

A confirmation experiment conducted to confirm the effectiveness of the present invention will be described.

Example 1
The thermoelectric conversion module was produced by the method similar to embodiment mentioned above.
In the invention examples 1 to 3 and the comparative examples 1 to 5, 12 half pairs of PN pairs were used as the thermoelectric conversion elements, using 3 mm × 3 mm × 5 mmt half-Heussler elements with Ni underlying gold electrodes. As the insulating layer, alumina having a thickness of 0.635 mm was used. As a glass-containing Ag paste for forming the first electrode portion, DD-1240D manufactured by Kyoto Elex Co., Ltd. was used. The heating conditions for forming the first electrode portion were a temperature of 850 ° C. and a holding time of 10 minutes. The thickness of the first electrode portion, the heating temperature at the time of bonding between the thermoelectric conversion element and the first electrode portion, and the pressure load were as described in Table 1.
The bonding atmosphere was as shown in Table 1, and in the bonding of the thermoelectric conversion element and the first electrode part and the second electrode part, the thermoelectric conversion element was directly laminated and bonded to the first electrode part and the second electrode part. .
In addition, the second electrode portion has the same configuration as the first electrode portion.

(With or without glass component)
After mechanically polishing the cross section of the first electrode portion of each of the obtained thermoelectric conversion modules, Ar ion etching (Cross Section Polisher SM-09010 manufactured by Nippon Denshi Co., Ltd.) is performed, EPMA analysis is performed, and metal and oxygen coexist The region to be treated was a glass component. And the presence or absence of the glass component in the interface of a 1st electrode part and a 1st insulating layer was confirmed. As a result, in the invention examples 1 to 3 and the comparative examples 1 to 3, glass components were all confirmed at the interface.

(Electric resistance)
Under the atmosphere, the temperature of the heating iron plate in contact with the first heat transfer plate side of the manufactured thermoelectric conversion module is 550 ° C, and the temperature of the cooling iron plate in contact with the second heat conduction plate side is 50 ° C. ) Was measured (initial resistance).
In addition, the temperature difference was continuously applied to the thermoelectric conversion module, the rate of increase from the initial value of the internal resistance with respect to time elapsed was calculated, and the durability of the thermoelectric conversion module after 24 hours elapsed was evaluated (internal resistance increase rate).
In the internal resistance, a variable resistance is placed between the output terminals of the thermoelectric conversion module with the temperature difference as described above, and the resistance is changed to measure the current value and the voltage value. In the graph, the voltage value when the current value is 0 is defined as the open circuit voltage, and the current value when the voltage value is 0 is defined as the maximum current. The open circuit voltage and the maximum current are connected in a straight line, and the slope of the straight line is taken as the internal resistance of the thermoelectric conversion module. The evaluation results are shown in Table 1.

(Porosity and thickness of the first electrode portion)
After mechanically polishing the cross section of the first electrode part of each of the obtained thermoelectric conversion modules, Ar ion etching (cross section polisher SM-09010 manufactured by Nippon Denshi Co., Ltd.) is performed, and a laser microscope (VKX-200 manufactured by Keyence Co., Ltd.) Cross-sectional observation was performed using Then, the obtained image was subjected to a binarization treatment, and the white portion was made Ag, and the black portion was made pores. The area of the black part was determined from the binarized image, and the porosity was calculated by the following equation. It measured by the cross section of five places, and the porosity of each cross section was carried out arithmetic mean, and it was set as the porosity of the 1st electrode part. The case where the porosity was 10% or more was evaluated as "B", and the case less than 10% was evaluated as "A".
Porosity P = area of black part (pores) / area of observation of first electrode 25 The thickness of the first electrode was measured using the above-mentioned laser microscope. The results are shown in Table 1.

In Comparative Example 1 in which the thickness of the first electrode portion was 30 μm or less, the initial resistance was high. In Comparative Example 1, the initial resistance was high, so the rate of increase in internal resistance was not measured. In Comparative Example 2 in which the heating temperature was low, the porosity was 10% or more, and the internal resistance increase rate was high. Moreover, in Comparative Example 3 in which the pressing load was less than 20 MPa, the porosity was high and the initial resistance was also high. In Comparative Example 3, the initial resistance was high, so the rate of increase in internal resistance was not measured. In Comparative Example 4 in which the bonding temperature was even lower than Comparative Example 2, bonding of the thermoelectric conversion elements could not be performed. In Comparative Example 5 in which the bonding load exceeded 50 MPa, cracking occurred in the first insulating layer. Therefore, in Comparative Example 4 and Comparative Example 5, the thickness, the porosity, and the electrical resistance of the first electrode portion are not evaluated.
On the other hand, in Inventive Examples 1 to 3, it was found that a thermoelectric conversion module was obtained in which the thickness of the first electrode portion is 30 μm or more and the porosity is less than 10% and the initial resistance and the internal resistance increase rate are also low. .

Example 2
Next, the thermoelectric conversion module was produced by the method similar to embodiment mentioned above.
A 12 mm pair of PN pairs was used as a thermoelectric conversion element, using a half-Heussler element with a Ni base gold electrode of 3 mm × 3 mm × 5 mmt. As the insulating layer, alumina having a thickness of 0.635 mm was used.

Here, in the Ag paste application step, as shown in Table 2, a glass-containing Ag paste (DD-1240D-01 manufactured by Kyoto Elex Co., Ltd.) and an Ag paste containing no glass component were applied. In addition, after apply | coating a glass containing paste, it bakes on conditions of temperature: 850 degreeC, holding time: 10 minutes, Then, Ag paste which does not contain a glass component is apply | coated, Temperature: 850 degreeC, holding time: 10 minutes Baking was performed under the conditions of

(Thickness ratio of the first electrode portion in the non-glass-containing region, presence or absence of glass component on the surface of the first electrode portion)
After mechanically polishing the cross section of the first electrode portion of each of the obtained thermoelectric conversion modules, Ar ion etching (Cross Section Polisher SM-09010 manufactured by Nippon Denshi Co., Ltd.) is performed, EPMA analysis is performed, and metal and oxygen coexist The region to be treated was a glass component. The measurement was performed in the range of 50 μm, and the magnification was 2000 ×. Then, the distance from the insulating layer to the glass particle present at the most distant position in the stacking direction was taken as the thickness Tg of the glass-containing region. Further, the thickness of the first electrode portion was measured, and the value obtained by subtracting the thickness Tg of the glass-containing region from the thickness of the first electrode portion was taken as the thickness Ta of the non-glass-containing region. In addition, it was observed whether a glass component was present on the surface of the first electrode portion.

(Presence or absence of peeling)
Using a laser microscope (VK X-200 manufactured by Keyence Corporation), the cross section of the first electrode portion of each of the obtained thermoelectric conversion modules is 10 μm from the glass-containing region at the end of the first electrode portion The case where it peeled above was evaluated as "presence".

Assuming that the thickness in the laminating direction of the glass-containing region is Tg, and the thickness in the laminating direction of the non-glass-containing region is Ta, if Ta / (Ta + Tg) is more than 0 and 0.5 or less, glass It was possible to suppress the occurrence of peeling at the boundary between the containing region and the non-glass-containing region.

10 thermoelectric conversion module 11 thermoelectric conversion element 20 first heat transfer plate (first insulating circuit board)
21 first insulating layer
25 first electrode unit 30 second heat transfer plate (second insulated circuit board)
31 2nd insulating layer
35 2nd electrode part

Claims (10)

1. A plurality of thermoelectric conversion elements, a first electrode portion disposed on one end side of the thermoelectric conversion elements, and a second electrode portion disposed on the other end side; the first electrode portion and the first electrode portion A thermoelectric conversion module in which a plurality of the thermoelectric conversion elements are electrically connected via a two-electrode unit,
   The first electrode portion comprising a first insulating layer at least one surface of which is made of alumina on one end side of the thermoelectric conversion element, and a sintered body of Ag formed on one surface of the first insulating layer And a first insulating circuit board provided with
   A glass component is present at the interface between the first electrode portion and the first insulating layer,
   The thermoelectric conversion module, wherein the first electrode portion has a thickness of 30 μm or more and a porosity of less than 10% at least in a region where the thermoelectric conversion element is disposed.
2. The first electrode portion is composed of a glass-containing region and a non-glass-containing region from the first insulating layer side in the stacking direction, and the thickness of the glass-containing region in the stacking direction is Tg, the non-glass-containing region 2. The thermoelectric conversion module according to claim 1, wherein Ta / (Ta + Tg) is more than 0 and not more than 0.5, where Ta is a thickness in the laminating direction of Ta.
3. The second electrode portion comprising a second insulating layer at least one surface of which is made of alumina on the other end side of the thermoelectric conversion element, and a sintered body of Ag formed on one surface of the second insulating layer And a second insulating circuit board provided with
   A glass component is present at the interface between the second electrode portion and the second insulating layer,
   The second electrode portion has a thickness of 30 μm or more and a porosity of less than 10% at least in a region where the thermoelectric conversion element is disposed. Thermoelectric conversion module described.
4. The second electrode portion is composed of a glass-containing region and a non-glass-containing region from the second insulating layer side in the stacking direction, and the thickness of the glass-containing region in the stacking direction is Tg, the non-glass-containing region 4. The thermoelectric conversion module according to claim 3, wherein Ta / (Ta + Tg) is more than 0 and not more than 0.5, where Ta is a thickness in the laminating direction of Ta.
5. A plurality of thermoelectric conversion elements, a first electrode portion disposed on one end side of the thermoelectric conversion elements, and a second electrode portion disposed on the other end side; the first electrode portion and the first electrode portion It is a manufacturing method of the thermoelectric conversion module formed by electrically connecting a plurality of the above-mentioned thermoelectric conversion elements via two electrode parts,
   The thermoelectric conversion module comprises, on one end side of the thermoelectric conversion element, a first insulating layer at least one surface of which is made of alumina, and a sintered body of Ag formed on one surface of the first insulating layer. A first insulating circuit board including the first electrode portion;
   An Ag paste applying step of applying an Ag paste containing Ag to a thickness of 30 μm or more on one surface of the first insulating layer;
   A firing step of firing the Ag paste to form a first electrode portion;
   Stacking the first insulating layer on one end side of the thermoelectric conversion element via the first electrode portion;
   A thermoelectric conversion element bonding step of pressing and heating the thermoelectric conversion element and the first insulating layer in the stacking direction and bonding the thermoelectric conversion elements;
   Have
   In the Ag paste application step, a glass-containing Ag paste is applied to at least the lowermost layer in contact with the first insulating layer,
   In the thermoelectric conversion element bonding step, the pressure load is in the range of 20 MPa or more and 50 MPa or less, and the heating temperature is 300 ° C. or more,
   The method of manufacturing a thermoelectric conversion module, wherein the first electrode portion has a thickness of 30 μm or more and a porosity of less than 10% at least in a region where the thermoelectric conversion element is disposed.
6. In the said Ag paste application | coating process, Ag paste which does not contain a glass component is apply | coated to the uppermost layer which contact | connects the said thermoelectric conversion element among the said 1st electrode parts, Manufacture of the thermoelectric conversion module of Claim 5 characterized by the above-mentioned. Method.
7. In the said lamination process, after arrange | positioning Ag joining material on the said 1st electrode part, the said thermoelectric conversion element is arrange | positioned, The manufacturing of the thermoelectric conversion module of Claim 5 or 6 characterized by the above-mentioned. Method.
8. The thermoelectric conversion module comprises, on one end side of the thermoelectric conversion element, a first insulating layer at least one surface of which is made of alumina, and a sintered body of Ag formed on one surface of the first insulating layer. A first insulating circuit substrate including the first electrode portion, and a second insulating layer having at least one surface made of alumina on the other end side of the thermoelectric conversion element, and the second insulating layer A second insulating circuit substrate including the second electrode portion made of a sintered body of Ag formed on one surface of the layer;
   In the Ag paste application step, an Ag paste containing Ag is applied to one surface of the first insulating layer and the second insulating layer with a thickness of 30 μm or more, and at least the first insulating layer and the second Apply a glass-containing Ag paste to the lowermost layer in contact with the insulating layer,
   In the firing step, the Ag paste is fired to form the first electrode portion and the second electrode portion.
   In the laminating step, the first insulating layer is laminated on one end side of the thermoelectric conversion element via the first electrode portion, and the second insulating portion is formed on the other end side of the thermoelectric conversion element. 2 stacked insulating layers,
   In the thermoelectric conversion element bonding step, the first insulating layer, the thermoelectric conversion element, and the second insulating layer are pressurized and heated in the stacking direction, and the first electrode portion, the thermoelectric conversion element, and Joining the thermoelectric conversion element and the second electrode portion,
   In the thermoelectric conversion element bonding step, the pressure load is in the range of 20 MPa to 50 MPa, and the heating temperature is 300 ° C. or higher, and at least the thermoelectric conversion element of the first electrode portion and the second electrode portion The method for manufacturing a thermoelectric conversion module according to any one of claims 5 to 7, wherein the thickness is set to 30 μm or more and the porosity is set to less than 10% in the region where the second layer is arranged. .
9. In the said Ag paste application | coating process, Ag paste which does not contain a glass component is apply | coated to the uppermost layer which contact | connects the said thermoelectric conversion element among the said 2nd electrode parts, The manufacture of the thermoelectric conversion module of Claim 8 characterized by the above-mentioned. Method.
10. The said thermoelectric conversion element is arrange | positioned after arrange | positioning Ag joining material on the said 2nd electrode part in the said lamination process, The manufacturing of the thermoelectric conversion module of Claim 8 or 9 characterized by the above-mentioned. Method.

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