KR102310807B1 - Thermoelectric element and method of preparating the same - Google Patents

Abstract

A thermoelectric element according to an embodiment of the present invention includes a first metal substrate, a first resin layer disposed on the first metal substrate, and a first resin layer in direct contact with the first metal substrate, and a plurality of layers disposed on the first resin layer a first electrode, a plurality of P-type thermoelectric legs and a plurality of N-type thermoelectric legs disposed on the plurality of first electrodes, and a plurality of first electrodes disposed on the plurality of P-type thermoelectric legs and the plurality of N-type thermoelectric legs. 2 electrodes, a second resin layer disposed on the plurality of second electrodes, and a second metal substrate disposed on the second resin layer, wherein the second metal substrate faces the first resin layer of the first metal substrate The surface includes a first region and a second region disposed inside the first region, a surface roughness of the second region is greater than a surface roughness of the first region, and the first resin layer is in the second region placed on top

Description

Thermoelectric element and manufacturing method thereof

The present invention relates to a thermoelectric element, and more particularly, to a junction structure of the thermoelectric element.

The thermoelectric phenomenon is a phenomenon that occurs by the movement of electrons and holes inside a material, and refers to direct energy conversion between heat and electricity.

A thermoelectric element is a generic term for a device using a thermoelectric phenomenon, and has a structure in which a P-type thermoelectric material and an N-type thermoelectric material are bonded between metal electrodes to form a PN junction pair.

Thermoelectric devices can be divided into devices using a temperature change in electrical resistance, devices using the Seebeck effect, which is a phenomenon in which electromotive force is generated by a temperature difference, and devices using the Peltier effect, which is a phenomenon in which heat absorption or heat is generated by current. .

Thermoelectric devices are widely applied to home appliances, electronic parts, and communication parts. For example, the thermoelectric element may be applied to an apparatus for cooling, an apparatus for heating, an apparatus for power generation, and the like. Accordingly, the demand for the thermoelectric performance of the thermoelectric element is increasing.

The thermoelectric element includes a substrate, an electrode, and a thermoelectric leg, a plurality of thermoelectric legs are disposed between the upper substrate and the lower substrate in an array form, a plurality of upper electrodes are disposed between the plurality of thermoelectric legs and the upper substrate, and a plurality of A plurality of lower electrodes are disposed between the thermoelectric leg and the lower substrate.

In general, the thermoelectric element may be disposed on a metal support. When the upper substrate and the lower substrate included in the thermoelectric element are ceramic substrates, heat loss may occur due to thermal resistance at the interface between the thermoelectric element and the metal support.

An object of the present invention is to provide a junction structure of a thermoelectric element.

A thermoelectric element according to an embodiment of the present invention includes a first metal substrate, a first resin layer disposed on the first metal substrate, and a first resin layer in direct contact with the first metal substrate, and a plurality of layers disposed on the first resin layer a first electrode, a plurality of P-type thermoelectric legs and a plurality of N-type thermoelectric legs disposed on the plurality of first electrodes, and a plurality of first electrodes disposed on the plurality of P-type thermoelectric legs and the plurality of N-type thermoelectric legs. 2 electrodes, a second resin layer disposed on the plurality of second electrodes, and a second metal substrate disposed on the second resin layer, wherein the second metal substrate faces the first resin layer of the first metal substrate The surface includes a first region and a second region disposed inside the first region, a surface roughness of the second region is greater than a surface roughness of the first region, and the first resin layer is in the second region placed on top

The first resin layer includes an epoxy resin and an inorganic filler, the inorganic filler includes a first inorganic filler and a second inorganic filler, and the particle size D50 of the first inorganic filler is the particle size of the second inorganic filler. It can be greater than D50.

The surface roughness of the second region may be larger than the particle size D50 of the first inorganic filler and smaller than the particle size D50 of the second inorganic filler.

The surface roughness of the second region may be 1.05 to 1.5 times the particle size D50 of the first inorganic filler.

The surface roughness of the second region may be 0.04 to 0.15 times the particle size D50 of the second inorganic filler.

A surface roughness of the second region may be 10 to 50 μm, a particle size D50 of the first inorganic filler may be 10 to 30 μm, and a particle size D50 of the second inorganic filler may be 250 to 350 μm.

The first resin layer includes an epoxy resin and an inorganic filler, and the content of the epoxy resin and the inorganic filler in the groove formed by the surface roughness of the second region is between the first metal substrate and the plurality of first electrodes. It may be different from the content of the epoxy resin and the inorganic filler in the middle region.

A portion of the epoxy resin and a portion of the first inorganic filler may be disposed in at least a portion of the groove formed by the surface roughness of the second region.

A surface of the first metal substrate facing the first resin layer further includes a third region disposed inside the second region, and the first resin layer includes a portion of the second region and the third region. and a surface roughness of the second region may be greater than a surface roughness of the third region.

It further includes an adhesive layer disposed between the first metal substrate and the first resin layer, and a portion of the adhesive layer may be disposed in at least a portion of the groove according to the surface roughness of the second region.

A thermoelectric element according to another embodiment of the present invention includes a first metal substrate, a first resin layer disposed on the first metal substrate, a plurality of first electrodes disposed on the first resin layer, and the plurality of first a plurality of P-type thermoelectric legs and a plurality of N-type thermoelectric legs disposed on an electrode, a plurality of second electrodes disposed on the plurality of P-type thermoelectric legs and a plurality of N-type thermoelectric legs, on the plurality of second electrodes a second resin layer disposed on the second resin layer, a second metal substrate disposed on the second resin layer, and a sealing part disposed between the first metal substrate and the second metal substrate, and facing the first resin layer The viewing surface of the first metal substrate includes a first area and a second area disposed inside the first area, the sealing part is disposed on the first area, and the first resin layer is the second area placed on the area.

The sealing part may include a sealing case spaced apart from a side surface of the first resin layer and a side surface of the second resin layer by a predetermined distance, and a sealing material disposed between the sealing case and the first area.

A width length of the first metal substrate may be greater than a width length of the second metal substrate.

The first metal substrate may emit heat, and the second metal substrate may absorb heat.

A thickness of the first metal substrate may be thinner than a thickness of the second metal substrate.

The first resin layer may be disposed to be spaced apart from a boundary between the first region and the second region by a predetermined distance.

The first resin layer may be formed in direct contact with the first metal substrate.

A thermoelectric element according to another embodiment of the present invention includes a first metal substrate, a first resin layer disposed on the first metal substrate, a plurality of first electrodes disposed on the first resin layer, and the plurality of first electrodes. a plurality of P-type thermoelectric legs and a plurality of N-type thermoelectric legs disposed on one electrode, a plurality of second electrodes disposed on the plurality of P-type thermoelectric legs and a plurality of N-type thermoelectric legs, the plurality of second electrodes A second resin layer disposed thereon, and a second metal substrate disposed on the second resin layer, wherein the first resin layer comprises an epoxy resin composition including an epoxy resin and an inorganic filler, and the inorganic The filler includes at least one of aluminum oxide and nitride, and the inorganic filler is included in 68 to 88 vol% of the epoxy resin composition.

The nitride may be included in 55 to 95 wt% of the inorganic filler.

The nitride may include at least one of boron nitride and aluminum nitride.

The boron nitride may be a boron nitride agglomerate in which plate-shaped boron nitride is aggregated.

The inorganic filler may include aluminum oxide having a particle size of 10 to 30 μm and boron nitride agglomerates having a particle size of D50 of 250 to 350 μm.

The first resin layer may be formed in direct contact with the first metal substrate.

A method of manufacturing a thermoelectric element according to an embodiment of the present invention includes bonding a resin layer and a metal layer, etching the metal layer to form a plurality of electrodes, a first region and a first region disposed inside the first region Forming a surface roughness in the second region of one surface of a metal substrate including two regions, arranging the second region of the metal substrate to contact the resin layer, the metal substrate and the resin layer thermocompression bonding.

Before disposing the second region of the metal substrate to contact the resin layer, the method may further include disposing an uncured adhesive layer between the metal substrate and the resin layer.

The disposing of the adhesive layer includes: applying the adhesive layer in an uncured state on a release film; disposing the resin layer on the adhesive layer; compressing the resin layer and the adhesive layer; removing, and disposing the surface from which the release film is removed on the second region of the metal substrate.

The resin layer may include an epoxy resin composition, and the adhesive layer may include the same epoxy resin composition as the epoxy resin composition included in the resin layer.

A thermoelectric element according to another embodiment of the present invention includes a first resin layer, a plurality of first electrodes disposed on the first resin layer, a plurality of P-type thermoelectric legs disposed on the plurality of first electrodes, and a plurality of a plurality of second electrodes disposed on the N-type thermoelectric legs, the plurality of P-type thermoelectric legs and the plurality of N-type thermoelectric legs, and a second resin layer disposed on the plurality of second electrodes, wherein At least one of the plurality of first electrodes includes a first surface facing the first resin layer, and a second surface facing a pair of P-type thermoelectric legs and N-type thermoelectric legs, the width of the first surface The length is different from the width length of the second side.

The width length of the second surface may be 0.8 to 0.95 times the width length of the first surface.

A side surface between the first surface and the second surface may include a curved surface having a predetermined curvature.

It further includes a first metal substrate on which the first resin layer is disposed, and a second metal substrate on the second resin layer, wherein the first resin layer is in direct contact with the first metal substrate.

According to an embodiment of the present invention, it is possible to obtain a thermoelectric device having excellent thermal conductivity, low heat loss, and high reliability. In particular, the thermoelectric element according to an embodiment of the present invention has a high bonding strength with a metal support and a simple manufacturing process.

1 is a cross-sectional view of a thermoelectric element according to an embodiment of the present invention.
2 is a top view of a metal substrate included in a thermoelectric device according to an embodiment of the present invention.
3 is a cross-sectional view of a metal substrate side of a thermoelectric element according to an embodiment of the present invention.
FIG. 4 is an enlarged view of one area of FIG. 3 .
5 to 6 are enlarged views of another area of FIG. 3 .
7 is a top view of a metal substrate included in a thermoelectric device according to another embodiment of the present invention.
8 is a cross-sectional view of the metal substrate side of the thermoelectric element including the metal substrate of FIG. 7 .
9 is a cross-sectional view of a thermoelectric element according to another embodiment of the present invention.
10 is a perspective view of the thermoelectric element according to FIG. 9 .
11 is an exploded perspective view of the thermoelectric element according to FIG. 9 .
12 to 13 show a method of manufacturing a thermoelectric element according to an embodiment of the present invention.
14 is an exemplary view in which a thermoelectric element according to an embodiment of the present invention is applied to a water purifier.
15 is an exemplary view in which a thermoelectric element according to an embodiment of the present invention is applied to a refrigerator.

Since the present invention can have various changes and can have various embodiments, specific embodiments are illustrated and described in the drawings. However, this is not intended to limit the present invention to specific embodiments, and it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the present invention.

Terms including an ordinal number such as second, first, etc. may be used to describe various elements, but the elements are not limited by the terms. The above terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the second component may be referred to as the first component, and similarly, the first component may also be referred to as the second component. and/or includes a combination of a plurality of related listed items or any of a plurality of related listed items.

When a component is referred to as being “connected” or “connected” to another component, it is understood that the other component may be directly connected or connected to the other component, but other components may exist in between. it should be On the other hand, when it is said that a certain element is "directly connected" or "directly connected" to another element, it should be understood that no other element is present in the middle.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In the present application, terms such as “comprise” or “have” are intended to designate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but one or more other features It should be understood that this does not preclude the existence or addition of numbers, steps, operations, components, parts, or combinations thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related art, and should not be interpreted in an ideal or excessively formal meaning unless explicitly defined in the present application. does not

Hereinafter, the embodiment will be described in detail with reference to the accompanying drawings, but regardless of the reference numerals, the same or corresponding components are given the same reference numerals, and the overlapping description thereof will be omitted.

1 is a cross-sectional view of a thermoelectric element according to an embodiment of the present invention, FIG. 2 is a top view of a metal substrate included in the thermoelectric element according to an embodiment of the present invention, and FIG. 3 is an embodiment of the present invention FIG. 4 is an enlarged view of one region of FIG. 3 , and FIGS. 5 to 6 are enlarged views of another region of FIG. 3 .

Referring to FIG. 1 , the thermoelectric element 100 includes a first resin layer 110 , a plurality of first electrodes 120 , a plurality of P-type thermoelectric legs 130 , a plurality of N-type thermoelectric legs 140 , and a plurality of of the second electrode 150 and the second resin layer 160 .

The plurality of first electrodes 120 are disposed between the first resin layer 110 and the lower surfaces of the plurality of P-type thermoelectric legs 130 and the plurality of N-type thermoelectric legs 140 , and the plurality of second electrodes 150 . ) is disposed between the second resin layer 160 and upper surfaces of the plurality of P-type thermoelectric legs 130 and the plurality of N-type thermoelectric legs 140 . Accordingly, the plurality of P-type thermoelectric legs 130 and the plurality of N-type thermoelectric legs 140 are electrically connected by the plurality of first electrodes 120 and the plurality of second electrodes 150 . A pair of P-type thermoelectric legs 130 and N-type thermoelectric legs 140 disposed between the first electrode 120 and the second electrode 150 and electrically connected may form a unit cell.

A pair of P-type thermoelectric legs 130 and N-type thermoelectric legs 140 may be disposed on each first electrode 120 , and disposed on each first electrode 120 on each second electrode 150 . A pair of N-type thermoelectric legs 140 and P-type thermoelectric legs 130 may be disposed such that one of the pair of P-type thermoelectric legs 130 and N-type thermoelectric legs 140 overlaps.

Here, the P-type thermoelectric leg 130 and the N-type thermoelectric leg 140 may be bismuth telluride (Bi-Te)-based thermoelectric legs including bismuth (Bi) and tellurium (Te) as main raw materials. P-type thermoelectric leg 130 is antimony (Sb), nickel (Ni), aluminum (Al), copper (Cu), silver (Ag), lead (Pb), boron (B), gallium with respect to 100wt% of the total weight A mixture containing 99 to 99.999 wt% of a bismuth telluride (Bi-Te)-based main raw material containing at least one of (Ga), tellurium (Te), bismuth (Bi) and indium (In) and Bi or Te 0.001 It may be a thermoelectric leg comprising 1 wt% to 1 wt%. For example, the main raw material is Bi-Se-Te, and may further include Bi or Te in an amount of 0.001 to 1 wt% of the total weight. N-type thermoelectric leg 140 is selenium (Se), nickel (Ni), aluminum (Al), copper (Cu), silver (Ag), lead (Pb), boron (B), gallium with respect to 100wt% of the total weight A mixture containing 99 to 99.999 wt% of a bismuth telluride (Bi-Te)-based main raw material containing at least one of (Ga), tellurium (Te), bismuth (Bi) and indium (In) and Bi or Te 0.001 It may be a thermoelectric leg comprising 1 wt % to 1 wt %. For example, the main raw material is Bi-Sb-Te, and may further include Bi or Te in an amount of 0.001 to 1 wt% of the total weight.

The P-type thermoelectric leg 130 and the N-type thermoelectric leg 140 may be formed in a bulk type or a stack type. In general, the bulk-type P-type thermoelectric leg 130 or the bulk-type N-type thermoelectric leg 140 heat-treats a thermoelectric material to manufacture an ingot, grinds the ingot and sieves to obtain a powder for the thermoelectric leg, and then It can be obtained through the process of sintering and cutting the sintered body. The laminated P-type thermoelectric leg 130 or the laminated N-type thermoelectric leg 140 is formed by applying a paste containing a thermoelectric material on a sheet-shaped substrate to form a unit member, and then stacking and cutting the unit member. can be obtained

In this case, the pair of P-type thermoelectric legs 130 and N-type thermoelectric legs 140 may have the same shape and volume, or may have different shapes and volumes. For example, since the electrical conductivity properties of the P-type thermoelectric leg 130 and the N-type thermoelectric leg 140 are different, the height or cross-sectional area of the N-type thermoelectric leg 140 is calculated as the height or cross-sectional area of the P-type thermoelectric leg 130 . may be formed differently.

The performance of the thermoelectric element according to an embodiment of the present invention may be expressed as a Seebeck index. The Seebeck index (ZT) can be expressed as in Equation (1).

Here, α is the Seebeck coefficient [V/K], σ is the electrical conductivity [S/m], and α ² σ is the power factor (Power Factor, [W/mK ² ]). And, T is the temperature, and k is the thermal conductivity [W/mK]. k can be expressed as a·c _p ·ρ, a is the thermal diffusivity [cm ² /S], c _p is the specific heat [J/gK], ρ is the density [g/cm ³ ].

In order to obtain the Seebeck index of the thermoelectric element, a Z value (V/K) is measured using a Z meter, and the Seebeck index (ZT) can be calculated using the measured Z value.

Here, the plurality of first electrodes 120 disposed between the first resin layer 110 and the P-type thermoelectric leg 130 and the N-type thermoelectric leg 140 , and the second resin layer 160 and the P-type thermoelectric leg 140 . The plurality of second electrodes 150 disposed between the leg 130 and the N-type thermoelectric leg 140 may include at least one of copper (Cu), silver (Ag), and nickel (Ni).

Also, the sizes of the first resin layer 110 and the second resin layer 160 may be different. For example, the volume, thickness, or area of one of the first resin layer 110 and the second resin layer 160 may be larger than the volume, thickness, or area of the other. Accordingly, heat absorbing performance or heat dissipation performance of the thermoelectric element may be improved.

In this case, the P-type thermoelectric leg 130 or the N-type thermoelectric leg 140 may have a cylindrical shape, a polygonal column shape, an elliptical column shape, or the like.

Alternatively, the P-type thermoelectric leg 130 or the N-type thermoelectric leg 140 may have a stacked structure. For example, the P-type thermoelectric leg or the N-type thermoelectric leg may be formed by stacking a plurality of structures coated with a semiconductor material on a sheet-shaped substrate and then cutting them. Accordingly, it is possible to prevent material loss and improve electrical conductivity properties.

Alternatively, the P-type thermoelectric leg 130 or the N-type thermoelectric leg 140 may be manufactured according to a zone melting method or a powder sintering method. According to the zone melting method, after an ingot is manufactured using a thermoelectric material, heat is slowly applied to the ingot to refine the particles so that they are rearranged in a single direction, and a thermoelectric leg is obtained by slow cooling. According to the powder sintering method, after an ingot is manufactured using a thermoelectric material, the ingot is pulverized and sieved to obtain a powder for a thermoelectric leg, and a thermoelectric leg is obtained through a sintering process.

According to an embodiment of the present invention, the first resin layer 110 may be disposed on the first metal substrate 170 , and the second metal substrate 180 may be disposed on the second resin layer 160 .

The first metal substrate 170 and the second metal substrate 180 may be made of aluminum, an aluminum alloy, copper, a copper alloy, or the like. The first metal substrate 170 and the second metal substrate 180 include a first resin layer 110 , a plurality of first electrodes 120 , a plurality of P-type thermoelectric legs 130 , and a plurality of N-type thermoelectric legs ( 140), a plurality of second electrodes 150, the second resin layer 160, etc. may be supported, and may be a region directly attached to an application to which the thermoelectric element 100 according to an embodiment of the present invention is applied. . Accordingly, the first metal substrate 170 and the second metal substrate 180 may be mixed with the first metal support and the second metal support, respectively.

The area of the first metal substrate 170 may be larger than the area of the first resin layer 110 , and the area of the second metal substrate 180 may be larger than the area of the second resin layer 160 . That is, the first resin layer 110 may be disposed in a region spaced apart by a predetermined distance from the edge of the first metal substrate 170 , and the second resin layer 160 is formed from the edge of the second metal substrate 180 . It may be arranged in a region spaced apart by a predetermined distance.

In this case, the width length of the first metal substrate 170 may be greater than the width length of the second metal substrate 180 , or the thickness of the first metal substrate 170 may be greater than the thickness of the second metal substrate 180 . . The first metal substrate 170 may be a heat dissipating part that emits heat, and the second metal substrate 180 may be a heat absorbing part that absorbs heat.

The first resin layer 110 and the second resin layer 160 may be formed of an epoxy resin composition including an epoxy resin and an inorganic filler. Here, the inorganic filler may be included in 68 to 88 vol% of the epoxy resin composition. When the inorganic filler is included in less than 68 vol%, the thermal conductivity effect may be low, and if the inorganic filler is included in more than 88 vol%, the adhesion between the resin layer and the metal substrate may be lowered, and the resin layer may be easily broken.

The thickness of the first resin layer 110 and the second resin layer 160 may be 0.02 to 0.6 mm, preferably 0.1 to 0.6 mm, more preferably 0.2 to 0.6 mm, and the thermal conductivity is 1W/mK or more. , preferably 10W/mK or more, more preferably 20W/mK or more. When the thickness of the first resin layer 110 and the second resin layer 160 satisfies these numerical ranges, the first resin layer 110 and the second resin layer 160 repeatedly contract and expand according to the temperature change. Even so, bonding between the first resin layer 110 and the first metal substrate 170 and bonding between the second resin layer 160 and the second metal substrate 180 may not be affected.

To this end, the epoxy resin may include an epoxy compound and a curing agent. In this case, the curing agent may be included in a volume ratio of 1 to 10 with respect to 10 volume ratio of the epoxy compound. Here, the epoxy compound may include at least one of a crystalline epoxy compound, an amorphous epoxy compound, and a silicone epoxy compound. The crystalline epoxy compound may include a mesogen structure. A mesogen is a basic unit of a liquid crystal and includes a rigid structure. And, the amorphous epoxy compound may be a conventional amorphous epoxy compound having two or more epoxy groups in the molecule, for example, may be a glycidyl ether product derived from bisphenol A or bisphenol F. Here, the curing agent may include at least one of an amine-based curing agent, a phenol-based curing agent, an acid anhydride-based curing agent, a polymercaptan-based curing agent, a polyaminoamide-based curing agent, an isocyanate-based curing agent, and a block isocyanate-based curing agent, and two or more types of curing agents may be used in combination.

The inorganic filler may include aluminum oxide and nitride, and the nitride may be included in 55 to 95 wt% of the inorganic filler, and more preferably 60 to 80 wt%. and bonding strength may be increased. Here, the nitride may include at least one of boron nitride and aluminum nitride. Here, the boron nitride may be a boron nitride agglomerate in which plate-shaped boron nitride is aggregated, and the surface of the boron nitride agglomerate is coated with a polymer having the following unit 1, or at least a portion of the pores in the boron nitride agglomerate is in the polymer having the following unit 1 can be charged by

Unit 1 is as follows.

[Unit 1]

wherein one of R ¹ , R ² , R ³ and R ⁴ is H, and the other is selected from the group consisting _{of C 1} -C ₃ alkyl, C ₂ -C ₃ alkene and C ₂ -C ₃ ^{alkyne, and R 5} may be a linear, branched or cyclic divalent organic linker having 1 to 12 carbon atoms.

In one embodiment, one of R ¹ , R ² , R ^{3 ,} and R ⁴ other than H is _{selected from C 2} ~C ₃ alkene, and the other one and the other one of the other is selected from C ₁ ~C ₃ alkyl. can be selected. For example, the polymer according to an embodiment of the present invention may include the following unit 2.

[Unit 2]

Alternatively, the ^{remainder of R 1} , R ² , R ³ and R ⁴ except for H may be selected to be different from each other from the group consisting _{of C 1} -C ₃ alkyl, C ₂ -C ₃ alkene, and C ₂ -C _{3 alkyne.} have.

In this way, when the polymer according to Unit 1 or Unit 2 is coated on the boron nitride agglomerate in which plate-shaped boron nitride is aggregated, and at least a part of the pores in the boron nitride agglomerate is filled, the air layer in the boron nitride agglomerate is minimized to minimize the amount of the boron nitride agglomerate. It is possible to increase the thermal conduction performance, and it is possible to prevent the cracking of the boron nitride agglomerates by increasing the bonding force between the plate-shaped boron nitrides. In addition, when the coating layer is formed on the boron nitride agglomerate in which the plate-shaped boron nitride is aggregated, it is easy to form a functional group, and when the functional group is formed on the coating layer of the boron nitride agglomerate, affinity with the resin can be increased.

In this case, the particle size D50 of the boron nitride agglomerates may be 250 to 350 μm, and the particle size D50 of the aluminum oxide may be 10 to 30 μm. When the particle size D50 of the boron nitride agglomerate and the particle size D50 of the aluminum oxide satisfy these numerical ranges, the boron nitride agglomerate and the aluminum oxide can be evenly dispersed in the epoxy resin composition, so that the entire resin layer has an even heat conduction effect and adhesive performance can have

As described above, when the first resin layer 110 is disposed between the first metal substrate 170 and the plurality of first electrodes 120 , the first metal substrate 170 and the plurality of first electrodes do not require a separate ceramic substrate. Heat transfer between the 120 is possible, and a separate adhesive or physical fastening means is not required due to the adhesive performance of the first resin layer 110 itself. Accordingly, the overall size of the thermoelectric element 100 may be reduced.

Here, the first metal substrate 170 may be in direct contact with the first resin layer 110 . To this end, a surface roughness is formed on the surface on which the first resin layer 110 is disposed among both surfaces of the first metal substrate 170 , that is, on the surface facing the first resin layer 110 of the first metal substrate 170 . can be Accordingly, it is possible to prevent the problem that the first resin layer 110 is lifted during thermocompression bonding between the first metal substrate 170 and the first resin layer 110 . In this specification, surface roughness means unevenness, and may be used interchangeably with surface roughness.

2 to 4 , the surface on which the first resin layer 110 is disposed among both surfaces of the first metal substrate 170 , that is, the surface facing the first resin layer 110 of the first metal substrate 170 . may include a first region 172 and a second region 174 , and the second region 174 may be disposed inside the first region 172 . That is, the first region 172 may be disposed within a predetermined distance from the edge of the first metal substrate 170 toward the center region, and the first region 172 may surround the second region 174 .

In this case, the surface roughness of the second region 174 may be greater than that of the first region 172 , and the first resin layer 110 may be disposed on the second region 174 . Here, the first resin layer 110 may be disposed to be spaced apart from the boundary between the first region 172 and the second region 174 by a predetermined distance. That is, the first resin layer 110 may be disposed on the second region 174 , and the edge of the first resin layer 110 may be located inside the second region 174 . Accordingly, at least a part of the groove 400 formed by the surface roughness of the second region 174 has a part of the first resin layer 110 , that is, the epoxy resin 600 included in the first resin layer 110 and A part of the inorganic filler 604 may permeate, and the adhesive force between the first resin layer 110 and the first metal substrate 170 may be increased.

However, the surface roughness of the second region 174 may be formed to be larger than the particle size D50 of some of the inorganic fillers included in the first resin layer 110 and smaller than the particle size D50 of some other parts. Here, the particle size D50 means a particle size corresponding to 50% of the weight percentage in the particle size distribution curve, that is, a particle size at which the passing mass percentage is 50%, and may be used interchangeably with the average particle size. For example, when the first resin layer 110 includes aluminum oxide and boron nitride as inorganic fillers, aluminum oxide does not affect the adhesion performance between the first resin layer 110 and the first metal substrate 170 , but , boron nitride has a smooth surface, and thus may adversely affect adhesion performance between the first resin layer 110 and the first metal substrate 170 . Accordingly, when the surface roughness of the second region 174 is formed to be larger than the particle size D50 of aluminum oxide included in the first resin layer 110 and smaller than the particle size D50 of boron nitride, the second region 174 is Since only aluminum oxide is disposed in the groove formed by the surface roughness and boron nitride cannot be disposed, the first resin layer 110 and the first metal substrate 170 may maintain high bonding strength.

Accordingly, the surface roughness of the second region 174 is 1.05 to 1.5 of the particle size D50 of the inorganic filler 604 having a relatively small size among the inorganic fillers included in the first resin layer 110, for example, aluminum oxide. times, the inorganic filler 602 having a relatively large size among the inorganic fillers included in the first resin layer 110, for example, may be 0.04 to 0.15 times the particle size D50 of boron nitride.

As described above, when the particle size D50 of the boron nitride agglomerates is 250 to 350 μm and the particle size D50 of aluminum oxide is 10 to 30 μm, the surface roughness of the second region 174 may be 1 to 50 μm. . Accordingly, only aluminum oxide is disposed in the groove formed by the surface roughness of the second region 174 , and boron nitride agglomerates may not be disposed.

According to this, the content of the epoxy resin and inorganic filler in the groove formed by the surface roughness of the second region 174 is the epoxy resin and inorganic filler in the middle region between the first metal substrate 170 and the plurality of first electrodes 120 . It may be different from the content of the filler.

Such surface roughness can be measured using a surface roughness measuring instrument. The surface roughness measuring device measures the cross-sectional curve using a probe, and the surface roughness can be calculated using the peak, trough, average, and reference length of the cross-sectional curve. In this specification, the surface roughness may mean an arithmetic mean roughness (Ra) by the center line average calculation method. The arithmetic mean roughness Ra may be obtained through Equation 2 below.

That is, when the cross-sectional curve obtained with the probe of the surface roughness measuring instrument is extracted as much as the reference length L, the average line direction is the x-axis and the height direction is the y-axis and expressed as a function (f(x)), by Equation 2 The obtained value can be expressed in μm-meter.

Meanwhile, referring to FIGS. 5 to 6 , at least one of the plurality of first electrodes 120 faces the first surface 121 disposed toward the first resin layer 110 , that is, the first resin layer 110 . The beam is a first face 121 and a second face 122 disposed toward the opposite face of the first face 121 , that is, a pair of P-type thermoelectric legs 130 and N-type thermoelectric legs 140 , that is, one A pair of P-type thermoelectric legs 130 and N-type thermoelectric legs 140 and a second surface 122 facing each other, the width length W1 of the first surface 121 and the second surface 122 are The width and length W2 may be different. For example, the width length W2 of the second surface 122 may be 0.8 to 0.95 times the width length W1 of the first surface 121 . As such, when the width length W1 of the first surface 121 is greater than the width length W2 of the second surface 122 , the contact area with the first resin layer 110 is increased, so that the first resin layer The bonding strength between 110 and the first electrode 120 may be increased.

In particular, referring to FIG. 6 , the side surface 123 between the first surface 121 and the second surface 122 may include a curved surface having a predetermined curvature. For example, between the second surface 122 and the side surface 123 may be a round shape having a predetermined curvature. Accordingly, it is easy to fill the space between the plurality of first electrodes 120 with an insulating resin, and accordingly, the plurality of first electrodes 120 may be stably supported on the first resin layer 110 , and the plurality of first electrodes 120 may be stably supported. Even if the electrodes 120 are disposed at a close distance, they may not have an electrical effect on neighboring electrodes.

In this case, the first electrode 120 may be made of a Cu layer, have a structure in which Cu, Ni and Au are sequentially stacked, or have a structure in which Cu, Ni, and Sn are sequentially stacked.

7 is a top view of a metal substrate included in a thermoelectric element according to another embodiment of the present invention, and FIG. 8 is a cross-sectional view of the metal substrate side of the thermoelectric element including the metal substrate of FIG. 7 . Duplicate descriptions of the same contents as those described with reference to FIGS. 1 to 6 will be omitted.

7 to 8 , among both surfaces of the first metal substrate 170 , the surface on which the first resin layer 110 is disposed, that is, the surface facing the first resin layer 110 of the first metal substrate 170 . is surrounded by the first region 172 and the first region 172 , and includes a second region 174 having a larger surface roughness than the first region 172 , and further includes a third region 176 . can do.

Here, the third region 176 may be disposed inside the second region 174 . That is, the third region 176 may be disposed to be surrounded by the second region 174 . Also, the surface roughness of the second region 174 may be greater than the surface roughness of the third region 176 .

In this case, the first resin layer 110 is disposed to be spaced apart from the boundary between the first region 172 and the second region 174 by a predetermined distance, and the first resin layer 110 includes a portion of the second region 174 and It may be disposed to cover the third region 176 .

In order to increase the bonding strength between the first metal substrate 170 and the first resin layer 110 , an adhesive layer 800 may be further disposed between the first metal substrate 170 and the first resin layer 110 .

The adhesive layer 800 may be the same epoxy resin composition as the epoxy resin composition constituting the first resin layer 110 . For example, after applying the same epoxy resin composition as the epoxy resin composition constituting the first resin layer 110 between the first metal substrate 170 and the first resin layer 110 in an uncured state, the cured state The first resin layer 110 may be laminated, and the first metal substrate 170 and the first resin layer 110 may be bonded in a manner that is pressurized at a high temperature.

At this time, a part of the adhesive layer 800, for example, a part of the epoxy resin and a part of the inorganic filler of the epoxy resin composition constituting the adhesive layer 800 may be disposed in at least a part of the groove according to the surface roughness of the second region 174. .

9 is a cross-sectional view of a thermoelectric element according to another embodiment of the present invention, FIG. 10 is a perspective view of the thermoelectric element according to FIG. 9 , and FIG. 11 is an exploded perspective view of the thermoelectric element according to FIG. 9 . Duplicate descriptions of the same content as those described with reference to FIGS. 1 to 8 will be omitted.

9 to 11 , the thermoelectric element 100 according to an embodiment of the present invention includes a sealing part 190 .

The sealing part 190 may be disposed on the side surface of the first resin layer 110 and the side surface of the second resin layer 160 on the first metal substrate 170 , that is, the sealing part 190 is the first metal substrate 170 . It is disposed between the substrate 170 and the second metal substrate 180 , and is the outermost of the plurality of first electrodes 120 , the outermost of the plurality of P-type thermoelectric legs 130 and the plurality of N-type thermoelectric legs 140 . It may be disposed to surround the outer periphery, the outermost portions of the plurality of second electrodes 150 , and the side surfaces of the second resin layer 160 . Accordingly, the first resin layer 110, the plurality of first electrodes 120, the plurality of P-type thermoelectric legs 130, the plurality of N-type thermoelectric legs 140, the plurality of second electrodes 150 and the second 2 The resin layer can be sealed from external moisture, heat, contamination, and the like.

In this case, the sealing part 190 may be disposed on the first area 172 . As such, when the sealing part 190 is disposed on the first region 172 having a small surface roughness, the sealing effect between the sealing part 190 and the first metal substrate 170 may be enhanced.

Here, the sealing part 190 is the side surface of the first resin layer 110 , the outermost portions of the plurality of first electrodes 120 , the plurality of P-type thermoelectric legs 130 and the plurality of N-type thermoelectric legs 140 . The sealing case 192, the sealing case 192, and the first metal substrate 170 are spaced apart from the outermost, the outermost of the plurality of second electrodes 150 and the side surface of the second resin layer 160 by a predetermined distance. may include a sealing material 194 disposed between the first region 172 of , and a sealing material 196 disposed between the side surfaces of the sealing case 192 and the second metal substrate 180 . In this way, the sealing case 192 may be in contact with the first metal substrate 170 and the second metal substrate 180 via the sealing materials 194 and 196 . Accordingly, when the sealing case 192 is in direct contact with the first metal substrate 170 and the second metal substrate 180, heat conduction occurs through the sealing case 192, and as a result, ΔT is lowered. can be prevented In particular, according to an embodiment of the present invention, a portion of the inner wall of the sealing case 192 is formed to be inclined, and the sealing material 196 is formed between the second metal substrate 180 and the sealing case from the side of the second metal substrate 180 . 192 is placed between. Accordingly, the volume between the first metal substrate 170 and the second metal substrate 180 increases, and heat exchange becomes active, so that a higher ΔT can be obtained.

Here, the sealing materials 194 and 196 may include at least one of an epoxy resin and a silicone resin, or a tape in which at least one of an epoxy resin and a silicone resin is applied to both surfaces. The sealing materials 194 and 196 serve to seal between the sealing case 192 and the first metal substrate 170 and between the sealing case 192 and the second metal substrate 180, and the first resin layer 110. , the sealing effect of the plurality of first electrodes 120 , the plurality of P-type thermoelectric legs 130 , the plurality of N-type thermoelectric legs 140 , the plurality of second electrodes 150 , and the second resin layer 160 . It can be raised, and it can be mixed with a finishing material, a finishing layer, a waterproofing material, a waterproofing layer, and the like.

Meanwhile, a guide groove G for drawing out the wires 200 and 202 connected to the electrodes may be formed in the sealing case 192 . To this end, the sealing case 192 may be an injection-molded product made of plastic or the like, and may be mixed with a sealing cover.

Here, the first metal substrate 170 may be a heat dissipating unit or a heat generating unit that emits heat, and the second metal substrate 180 may be a heat absorbing unit or a cooling unit that absorbs heat. To this end, the width length of the first metal substrate 170 may be greater than the width length of the second metal substrate 180 , or the thickness of the first metal substrate 170 may be thinner than the thickness of the second metal substrate 180 . have. Accordingly, the first metal substrate 170 serving as the heat dissipating unit or the heat generating unit may be implemented to have low thermal resistance, and the sealing unit 190 may be stably disposed. In particular, the first metal substrate 170 may be formed to be larger than the second metal substrate 180 by an area corresponding to the first region 172 in order to stably dispose the sealing part 190 . Since the second metal substrate 180, which is the heat absorbing part or the cooling part, can make contact with the contacting object with a minimum area, heat loss can be minimized. When the thermoelectric element according to the embodiment of the present invention is applied to an application for cooling, the thickness of the second metal substrate 180 may vary depending on the required heat capacity of the cooling system.

In the embodiment described with reference to FIGS. 9 to 11 , the first metal substrate 170 includes the first metal substrate 170 as well as the embodiment of FIGS. 1 to 6 including the first region 172 and the second region 174 . ) may also be applied to the embodiments of FIGS. 7 to 8 including the first region 172 , the second region 174 , and the third region 176 .

Hereinafter, a method of manufacturing a thermoelectric element according to an embodiment of the present invention will be described with reference to the drawings.

12 to 13 show a method of manufacturing a thermoelectric element according to an embodiment of the present invention.

Referring to FIG. 12 , a metal layer is bonded on the resin layer ( S1200 ), and a plurality of electrodes are formed by etching the metal layer ( S1210 ). In order to etch the metal layer, after disposing a plurality of electrode-shaped masks on the metal layer, an etching solution may be sprayed. In this way, when the metal layer is etched, the degree of freedom of design change can be increased, and the distance between electrodes can be formed narrowly. Here, the electrode may include at least one of Cu, Ni, Au, and Sn. For example, the electrode may be formed of a Cu layer. Alternatively, the electrode may have a structure in which Cu, Ni, and Au are sequentially stacked, or Cu, Ni, and Sn are sequentially stacked. To this end, the metal layer bonded on the resin layer in step S1200 may include a Ni layer and an Au layer plated on the Cu layer, or may include a Ni layer and a Sn layer plated on the Cu layer. Alternatively, the metal layer bonded on the resin layer in step S1200 is a Cu layer, and after forming a plurality of electrodes by etching the Cu layer, sequentially plating the Ni layer and the Au layer on the plurality of electrodes, or the Ni layer and the Sn layer can be sequentially plated.

Meanwhile, a surface roughness is formed on one of both surfaces of the metal substrate (S1220). Surface roughness may be performed by various methods such as sandblasting, sawing, casting, forging, turning, milling, boring, drilling, electric discharge machining, etc., but is not limited thereto. As described above, the surface roughening may be performed only on a partial area within one of both surfaces of the metal substrate. For example, the surface roughness is performed on a partial region including the edge of the metal substrate, that is, excluding the first region, and the remaining region including the middle of the metal substrate, that is, the second region as in the embodiment of FIGS. 1 to 6 . can be Alternatively, as in the embodiment of FIGS. 7 to 8 , the surface roughness is a partial region including the edge between the metals, that is, a partial region including the first region and the middle of the metal substrate, ie, the third region, except for the remaining region, that is, It may be performed in the second area.

Next, the metal substrate on which the surface roughness is formed and the resin layer are bonded (S1230). To this end, one side of the metal substrate on which the surface roughness is formed and the opposite side of the surface on which the plurality of electrodes are formed among both surfaces of the resin layer are disposed to contact each other, and then the metal substrate and the resin layer may be thermocompression-bonded. To this end, before disposing the second region of the metal substrate to be in contact with the resin layer, the method may further include disposing an uncured adhesive layer between the metal substrate and the resin layer.

More specifically, referring to FIGS. 13(a), 13(b) and 13(c), a resin layer is applied on the Cu layer, an adhesive layer is applied on the release film, and the surface roughness on the metal substrate The process of forming is performed respectively. Here, the epoxy resin composition constituting the resin layer and the epoxy resin composition constituting the adhesive layer may be the same epoxy resin composition.

Referring to FIG. 13(d), when a Cu layer for electrode formation is further disposed on the resin layer applied in FIG. 13(a) and then thermocompressed, the resin layer is cured and has a structure as shown in FIG. 13(e) can be obtained.

Next, as shown in FIG. 13(f), after etching the Cu layer to form a plurality of electrodes, a plating layer may be formed on the plurality of electrodes as shown in FIG. 13(g).

Thereafter, the adhesive layer applied on the release film in FIG. 13(b) is disposed on the opposite side of the surface on which the plurality of electrodes are formed among both surfaces of the resin layer and compressed, and then the release film may be removed. In this case, the adhesive layer may be in a semi-cured state.

Then, the surface from which the release film is removed is disposed on a metal substrate having a roughened surface and pressed, the metal substrate and the resin layer may be bonded.

According to this, a part of the adhesive layer in the semi-cured state may permeate into the groove according to the surface roughness on the metal substrate.

Hereinafter, an example in which a thermoelectric element according to an embodiment of the present invention is applied to a water purifier will be described with reference to FIG. 14 .

14 is a block diagram of a water purifier to which a thermoelectric element is applied according to an embodiment of the present invention.

The water purifier 1 to which the thermoelectric element is applied according to an embodiment of the present invention includes a raw water supply pipe 12a, a purified water tank inlet pipe 12b, a purified water tank 12, a filter assembly 13, a cooling fan 14, and a heat storage tank ( 15), a cold water supply pipe 15a, and a thermoelectric device 1000 .

The raw water supply pipe 12a is a supply pipe that introduces water to be purified from a water source into the filter assembly 13 , and the purified water tank inlet pipe 12b introduces water purified from the filter assembly 13 into the purified water tank 12 . The cold water supply pipe 15a is a supply pipe through which the cold water cooled to a predetermined temperature by the thermoelectric device 1000 in the purified water tank 12 is finally supplied to the user.

The purified water tank 12 temporarily receives purified water to store and supply the purified water through the filter assembly 13 and introduced through the purified water tank inlet pipe 12b to the outside.

The filter assembly 13 includes a precipitation filter 13a, a pre-carbon filter 13b, a membrane filter 13c, and a post-carbon filter 13d.

That is, water flowing into the raw water supply pipe 12a may pass through the filter assembly 13 and be purified.

The heat storage tank 15 is disposed between the purified water tank 12 and the thermoelectric device 1000 to store cold air formed in the thermoelectric device 1000 . The cold air stored in the heat storage tank 15 is applied to the purified water tank 12 to cool the water contained in the purified water tank 120 .

The heat storage tank 15 may be in surface contact with the purified water tank 12 so that cold air can be smoothly transmitted.

As described above, the thermoelectric device 1000 has a heat absorbing surface and a heat generating surface, and one side is cooled and the other side is heated by the movement of electrons on the P-type semiconductor and the N-type semiconductor.

Here, one side may be the purified water tank 12 side, and the other side may be the opposite side of the purified water tank 12 .

In addition, as described above, the thermoelectric device 1000 has excellent waterproof and dustproof performance, and improved thermal fluid performance, so that the purified water tank 12 can be efficiently cooled in the water purifier.

Hereinafter, an example in which a thermoelectric element according to an embodiment of the present invention is applied to a refrigerator will be described with reference to FIG. 15 .

15 is a block diagram of a refrigerator to which a thermoelectric element is applied according to an embodiment of the present invention.

The refrigerator includes a simon evaporating chamber cover 23 , an evaporating chamber partition wall 24 , a main evaporator 25 , a cooling fan 26 , and a thermoelectric device 1000 in the simon evaporating chamber.

The inside of the refrigerator is divided into a sim-on storage chamber and a sim-on evaporation chamber by the sim-on evaporation chamber cover 23 .

In detail, the inner space corresponding to the front of the simon evaporating chamber cover 23 may be defined as the simon storage chamber, and the inner space corresponding to the rear of the simon evaporating chamber cover 23 may be defined as the simon evaporating chamber.

A discharge grill 23a and a suction grill 23b may be respectively formed on the front surface of the sim-on evaporation chamber cover 23 .

The evaporation chamber partition wall 24 is installed at a point spaced forward from the rear wall of the inner cabinet, and partitions a space in which the deep greenhouse storage system is placed and a space in which the main evaporator 25 is placed.

The cold air cooled by the main evaporator 25 is supplied to the freezing chamber and then returned to the main evaporator.

The thermoelectric device 1000 is accommodated in the sim-on evaporation chamber, and has a structure in which the heat absorbing surface faces the drawer assembly of the sim-on storage chamber and the heat-generating surface faces the evaporator. Accordingly, it can be used to rapidly cool the food stored in the drawer assembly to an ultra-low temperature state of minus 50 degrees Celsius or less by using the endothermic phenomenon generated by the thermoelectric device 1000 .

In addition, as described above, the thermoelectric device 1000 has excellent waterproof and dustproof performance, and improved thermal fluid performance, so that the drawer assembly can be efficiently cooled in the refrigerator.

The thermoelectric element according to an embodiment of the present invention may be applied to a device for power generation, a device for cooling, a device for heating, and the like. Specifically, the thermoelectric element according to an embodiment of the present invention is mainly an optical communication module, a sensor, a medical device, a measuring device, aerospace industry, a refrigerator, a chiller, a car ventilation seat, a cup holder, a washing machine, a dryer, and a wine cellar. , water purifiers, power supplies for sensors, thermopiles, and the like.

Here, as an example in which the thermoelectric element according to an embodiment of the present invention is applied to a medical device, there is a PCR (Polymerase Chain Reaction) device. PCR equipment is equipment for determining the nucleotide sequence of DNA by amplifying DNA, and it requires precise temperature control and thermal cycle. To this end, a Peltier-based thermoelectric element may be applied.

As another example in which the thermoelectric element according to an embodiment of the present invention is applied to a medical device, there is a photodetector. Here, the photodetector includes an infrared/ultraviolet detector, a charge coupled device (CCD) sensor, an X-ray detector, and a Thermoelectric Thermal Reference Source (TTRS). A Peltier-based thermoelectric element may be applied for cooling the photodetector. Accordingly, it is possible to prevent a change in wavelength, a decrease in output, and a decrease in resolution due to an increase in the temperature inside the photodetector.

As another example in which the thermoelectric element according to an embodiment of the present invention is applied to a medical device, an immunoassay field, an in vitro diagnostics field, a general temperature control and cooling system, Physical therapy fields, liquid chiller systems, blood/plasma temperature control, etc. Accordingly, precise temperature control is possible.

As another example in which the thermoelectric element according to an embodiment of the present invention is applied to a medical device, there is an artificial heart. Accordingly, power can be supplied to the artificial heart.

Examples of the thermoelectric element according to an embodiment of the present invention applied to the aerospace industry include a star tracking system, a thermal imaging camera, an infrared/ultraviolet detector, a CCD sensor, the Hubble Space Telescope, and a TTRS. Accordingly, the temperature of the image sensor may be maintained.

As another example in which the thermoelectric element according to an embodiment of the present invention is applied to the aerospace industry, there are a cooling device, a heater, a power generation device, and the like.

In addition to this, the thermoelectric element according to an embodiment of the present invention may be applied for power generation, cooling, and heating in other industrial fields.

Although the above has been described with reference to preferred embodiments of the present invention, those skilled in the art can variously modify and change the present invention within the scope without departing from the spirit and scope of the present invention as set forth in the claims below. You will understand that it can be done.

Claims (10)

a first metal substrate;
a first resin layer disposed on the first metal substrate;
a third resin layer disposed between the first metal substrate and the first resin layer;
a plurality of first electrodes disposed on the first resin layer;
a plurality of P-type thermoelectric legs and a plurality of N-type thermoelectric legs disposed on the plurality of first electrodes;
a plurality of second electrodes disposed on the plurality of P-type thermoelectric legs and the plurality of N-type thermoelectric legs;
a second resin layer disposed on the plurality of second electrodes, and
and a second metal substrate disposed on the second resin layer,
The width length of the first metal substrate is greater than the width length of the second metal substrate,
A contact area between the third resin layer and the first metal substrate is larger than a contact area between the third resin layer and the first resin layer. According to claim 1,
The first resin layer includes an epoxy resin composition, and the third resin layer includes the same epoxy resin composition as the epoxy resin composition included in the first resin layer. According to claim 1,
At least one of the first resin layer and the third resin layer includes an epoxy resin and an inorganic filler. According to claim 1,
A thickness of the first resin layer is different from a thickness of the third resin layer. 5. The method of claim 4,
A thickness of the first resin layer is greater than a thickness of the third resin layer. According to claim 1,
An area of each of the first resin layer and the third resin layer is smaller than an area of the first metal substrate. delete 7. The method of claim 6,
The first resin layer and the third resin layer are disposed in a region spaced apart from an edge of the first metal substrate by a predetermined distance. 9. The method of claim 8,
Further comprising a sealing portion disposed between the first metal substrate and the second metal substrate,
The sealing part is a thermoelectric element disposed on the first metal substrate to be spaced apart from a side surface of the first resin layer and a side surface of the third resin layer by a predetermined distance. According to claim 1,
At least one of the volume, thickness, and area of the first resin layer is different from at least one of the volume, thickness, and area of the second resin layer.

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