WO2017209549A1

WO2017209549A1 - Thermoelectric leg and thermoelectric element comprising same

Info

Publication number: WO2017209549A1
Application number: PCT/KR2017/005754
Authority: WO
Inventors: 토쇼츠요시
Original assignee: 엘지이노텍 주식회사
Priority date: 2016-06-01
Filing date: 2017-06-01
Publication date: 2017-12-07

Abstract

According to one embodiment of the present invention, a thermoelectric leg comprises: a thermoelectric material layer comprising Bi and Te; a first metal layer and a second metal layer respectively arranged on one surface of the thermoelectric material layer and on a surface different from the one surface; a first adhesive layer arranged between the thermoelectric material layer and the first metal layer and comprising the Te, and a second adhesive layer arranged between the thermoelectric material layer and the second metal layer and comprising the Te; and a first plating layer arranged between the first metal layer and the first adhesive layer, and a second plating layer arranged between the second metal layer and the second adhesive layer, wherein the thermoelectric material layer is arranged between the first metal layer and the second metal layer, the amount of the Te is higher than the amount of the Bi from the central surface of the thermoelectric material layer to the interface between the thermoelectric material layer and the first adhesive layer, and the amount of the Te is higher than the amount of the Bi from the central surface of the thermoelectric material layer to the interface between the thermoelectric material layer and the second adhesive layer.

Description

Thermoelectric Legs and Thermoelectric Devices Comprising the Same

The present invention relates to a thermoelectric element, and more particularly to a thermoelectric leg included in the thermoelectric element.

Thermoelectric phenomenon is a phenomenon caused by the movement of electrons and holes in a material, and means a 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 leg and an N-type thermoelectric leg are bonded between metal electrodes to form a PN junction pair.

Thermoelectric elements may be classified into a device using a temperature change of the electrical resistance, a device using the Seebeck effect, a phenomenon in which electromotive force is generated by the temperature difference, a device using a Peltier effect, a phenomenon in which endothermic or heat generation by current occurs. .

Thermoelectric devices have been applied to a variety of home appliances, electronic components, communication components and the like. For example, the thermoelectric element may be applied to a cooling device, a heating device, a power generating device, or the like. Accordingly, the demand for thermoelectric performance of thermoelectric elements is increasing.

Meanwhile, in order to stably bond the thermoelectric legs to the electrodes, a metal layer may be formed between the thermoelectric legs and the electrodes. In this case, a plating layer may be formed between the thermoelectric leg and the metal layer in order to prevent a phenomenon in which the thermoelectric performance is deteriorated by a reaction between the semiconductor material and the metal layer in the thermoelectric leg and to prevent oxidation of the metal layer.

However, in the process of simultaneously sintering the plating layer and the thermoelectric leg, a part of the semiconductor material in the thermoelectric leg may be diffused into the plating layer, which may result in uneven distribution of the semiconductor material at the boundary between the plating layer and the thermoelectric leg. For example, when the thermoelectric legs include Bi and Te, when Te is diffused into the plating layer, a Bi rich layer containing a relatively large amount of Bi may be formed. Within the Bi-rich layer, the proper stoichiometric ratios of Bi and Te are destroyed, resulting in an increase in resistance, which can result in degradation of the thermoelectric device performance.

It is an object of the present invention to provide a thermoelectric device having excellent thermoelectric performance and a thermoelectric leg included therein.

According to an embodiment of the present invention, a thermoelectric leg includes a thermoelectric material layer including Bi and Te, a first metal layer and a second metal layer respectively disposed on one side and the other side of the thermoelectric material layer, and the thermoelectric material. A second bonding layer disposed between the material layer and the first metal layer and disposed between the first bonding layer including the Te and the thermoelectric material layer and the second metal layer, and including the Te; and the first A first plating layer disposed between the metal layer and the first bonding layer, and a second plating layer disposed between the second metal layer and the second bonding layer, wherein the thermoelectric material layer includes the first metal layer and the second metal layer. The Te content is disposed between the center surface of the thermoelectric material layer and the interface between the thermoelectric material layer and the first bonding layer is higher than the Bi content, and the heat from the center surface of the thermoelectric material layer to the heat The Te content to the interface between the material layer and the second bonding layer is higher than the Bi content.

The Te content at a predetermined point in the interface between the thermoelectric material layer and the first bonding layer from the center surface of the thermoelectric material layer may be 0.8 to 1 times the Te content of the center surface of the thermoelectric material layer.

The Te content of the first bonding layer may be 0.8 to 1 times the Te content of the thermoelectric material layer.

The Te content from the interface between the thermoelectric material layer and the first bonding layer to the interface between the first bonding layer and the first plating layer may be the same.

Te content at a predetermined point within 100 μm thickness in the direction of the center surface of the thermoelectric material layer from the interface between the thermoelectric material layer and the first bonding layer is 0.8 to 1 times the Te content of the center surface of the thermoelectric material layer. Can be.

At least one of the first plating layer and the second plating layer may include at least one metal of Ni, Sn, Ti, Fe, Sb, Cr, and Mo, respectively.

At least one of the first bonding layer and the second bonding layer may further include at least one metal selected from the first plating layer and the second plating layer.

At least one of the first metal layer and the second metal layer may be selected from copper, a copper alloy, aluminum, and an aluminum alloy.

The Te content of at least one of the first bonding layer and the second bonding layer may be 0.9 to 1 times the Te content of the thermoelectric material layer.

The Te content of at least one of the first bonding layer and the second bonding layer may be 0.95 to 1 times the Te content of the thermoelectric material layer.

The thickness of the first plating layer may be 1 μm to 20 μm.

The thermoelectric material layer and the first bonding layer may directly contact each other, and the thermoelectric material layer and the second bonding layer may directly contact each other.

The first bonding layer and the first plating layer may directly contact each other, and the second bonding layer and the second plating layer may directly contact each other.

The first plating layer and the first metal layer may directly contact each other, and the second plating layer and the second metal layer may directly contact each other.

A thermoelectric device according to an embodiment of the present invention includes a first substrate, a plurality of P-type thermoelectric legs and a plurality of N-type thermoelectric legs disposed alternately on the first substrate, the plurality of P-type thermoelectric legs, and the plurality of A second substrate disposed on an N-type thermoelectric leg, and a plurality of electrodes connecting the plurality of P-type thermoelectric legs and the plurality of N-type thermoelectric legs in series, wherein the plurality of P-type thermoelectric legs and the plurality of electrodes The N-type thermoelectric leg includes a thermoelectric material layer including Bi and Te, a first metal layer and a second metal layer respectively disposed on one side and the other side of the thermoelectric material layer, the thermoelectric material layer and the first layer. 1 is disposed between the metal layer, the first bonding layer containing the Te and the thermoelectric material layer and the second metal layer disposed between, the second bonding layer comprising the Te, and the first metal layer and the first Placed between bonding layers A first plating layer and a second plating layer disposed between the second metal layer and the second bonding layer, wherein the thermoelectric material layer is disposed between the first metal layer and the second metal layer, and The Te content from the center plane to the interface between the thermoelectric material layer and the first bonding layer is higher than the Bi content, and the Te content from the center plane of the thermoelectric material layer to the interface between the thermoelectric material layer and the second bonding layer. Is higher than the Bi content.

According to an embodiment of the present invention, a method of manufacturing a thermoelectric leg may include preparing a first metal substrate, forming a first plating layer on the first metal substrate, and including Te on the first plating layer. Forming a bonding layer, disposing a thermoelectric material layer including Bi and Te on an upper surface of the first bonding layer, and forming a second metal substrate having a second bonding layer and a second plating layer on the thermoelectric material layer. Batching, and sintering.

The forming of the first bonding layer may include applying a slurry including Te on the first plating layer, and performing a heat treatment.

The forming of the first bonding layer may include vacuum depositing a source including Te and a material of the first plating layer on the first plating layer.

The forming of the first bonding layer may include adding Te ions in a plating solution for forming the first plating layer.

The thermoelectric material layer may be disposed between the first bonding layer and the second bonding layer, and the first bonding layer and the second bonding layer may face each other.

The sintering step may further include the step of pressing.

The metal substrate may be selected from copper, copper alloys, aluminum and aluminum alloys.

The first plating layer may include at least one of Ni, Sn, Ti, Fe, Sb, Cr, and Mo.

The first bonding layer may further include at least one of Ni, Sn, Ti, Fe, Sb, Cr, and Mo.

The sintering may include a discharge plasma sintering method.

The heat treatment may include a step in which Te is diffused and reacted from the first plating layer surface layer.

According to the embodiment of the present invention, the thermoelectric performance is excellent, and a thin and small thermoelectric element can be obtained. In particular, it is possible to obtain a thermoelectric leg that is stably bonded to the electrode and that the distribution of semiconductor material is uniform, thereby providing stable thermoelectric performance.

1 is a cross-sectional view of a thermoelectric element, and FIG. 2 is a perspective view of the thermoelectric element.

3 is a cross-sectional view of a thermoelectric leg and an electrode according to an embodiment of the present invention.

4 shows a method of manufacturing a thermoelectric leg of a laminated structure.

5 illustrates a conductive layer formed between unit members in the laminated structure of FIG. 4.

6 shows a unit thermoelectric leg of a laminated structure.

7 is a cross-sectional view of a thermoelectric leg according to an embodiment of the present invention.

FIG. 8A is a schematic diagram of the thermoelectric leg of FIG. 7, and FIG. 8B is a cross-sectional view of the thermoelectric element including the thermoelectric leg of FIG. 8A.

9 is a graph showing the change rate of resistance according to the thickness of the bonding layer.

10 is a flowchart illustrating a method of manufacturing a thermoelectric leg according to an embodiment of the present invention.

FIG. 11 is a view schematically showing a Te content distribution in a thermoelectric leg manufactured according to the method of FIG. 10.

FIG. 12 is a graph illustrating composition distribution for each region in a thermoelectric leg manufactured according to the method of FIG. 10.

FIG. 13 is a view schematically showing a Te content distribution in a thermoelectric leg manufactured according to a comparative example. FIG.

14 is a graph analyzing composition distribution for each region in a thermoelectric leg manufactured according to a comparative example.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated and described in the drawings. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention.

Terms including ordinal numbers, such as second and first, may be used to describe various components, but the components are not limited by the terms. The 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. The term and / or includes a combination of a plurality of related items or any item of a plurality of related items.

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

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination 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. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments will be described in detail with reference to the accompanying drawings, and the same or corresponding components will be given the same reference numerals regardless of the reference numerals, and redundant description thereof will be omitted.

1 to 2, the thermoelectric element 100 includes a lower substrate 110, a lower electrode 120, a P-type thermoelectric leg 130, an N-type thermoelectric leg 140, an upper electrode 150, and an upper substrate. 160.

The lower electrode 120 is disposed between the lower substrate 110 and the lower bottom surface of the P-type thermoelectric leg 130 and the N-type thermoelectric leg 140, and the upper electrode 150 is the upper substrate 160 and the P-type. Disposed between the thermoelectric leg 130 and the upper bottom surface of the N-type thermoelectric leg 140. Accordingly, the plurality of P-type thermoelectric legs 130 and the plurality of N-type thermoelectric legs 140 are electrically connected by the lower electrode 120 and the upper electrode 150. A pair of P-type thermoelectric legs 130 and N-type thermoelectric legs 140 disposed between the lower electrode 120 and the upper electrode 150 and electrically connected to each other may form a unit cell.

For example, when a voltage is applied to the lower electrode 120 and the upper electrode 150 through the

lead wires

181 and 182, a current is transmitted from the P-type thermoelectric leg 130 to the N-type thermoelectric leg 140 due to the Peltier effect. The flowing substrate absorbs heat to act as a cooling unit, and the substrate flowing current from the N-type thermoelectric leg 140 to the P-type thermoelectric leg 130 may be heated to act as a heat generating unit.

The P-type thermoelectric leg 130 and the N-type thermoelectric leg 140 may be bismuth fluoride (Bi-Te) -based thermoelectric legs including bismuth (Bi) and tellurium (Te) as main materials. P-type thermoelectric leg 130 is antimony (Sb), nickel (Ni), aluminum (Al), copper (Cu), silver (Ag), lead (Pb), boron (B), gallium relative to the total weight 100wt% A mixture comprising 99 to 99.999 wt% of bismustelulide (Bi-Te) -based main raw material including at least one of (Ga), tellurium (Te), bismuth (Bi) and indium (In) and Bi or Te 0.001 It may be a thermoelectric leg including to 1wt%. For example, the main raw material is Bi-Se-Te, and may further include Bi or Te as 0.001 to 1wt% 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 relative to the total weight 100wt% A mixture comprising 99 to 99.999 wt% of bismustelulide (Bi-Te) -based main raw material including at least one of (Ga), tellurium (Te), bismuth (Bi) and indium (In) and Bi or Te 0.001 It may be a thermoelectric leg including to 1wt%. For example, the main raw material is Bi-Sb-Te, and may further include Bi or Te as 0.001 to 1wt% 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 stacked type. In general, the bulk P-type thermoelectric leg 130 or the bulk N-type thermoelectric leg 140 is heat-treated thermoelectric material to produce an ingot (ingot), crushed and ingot to obtain a powder for thermoelectric leg, then Sintering, and can be obtained through the process of cutting the sintered body. The stacked P-type thermoelectric leg 130 or the stacked N-type thermoelectric leg 140 is formed by applying a paste including a thermoelectric material on a sheet-shaped substrate to form a unit member, and then stacking and cutting the unit members. Can be obtained.

In this case, the pair of P-type thermoelectric leg 130 and the N-type thermoelectric leg 140 may have the same shape and volume, or may have different shapes and volumes. For example, since the electrical conduction characteristics of the P-type thermoelectric leg 130 and the N-type thermoelectric leg 140 are different, the height or the cross-sectional area of the N-type thermoelectric leg 140 is the height or the cross-sectional area of the P-type thermoelectric leg 130. It can also be formed differently.

The performance of the thermoelectric device according to the exemplary embodiment of the present invention may be represented by Seebeck index. The Seebeck index ZT may be expressed as in Equation 1.

Where α is the Seebeck coefficient [V / K], sigma is the electrical conductivity [S / m], and α ² sigma is the Power Factor [W / mK ² ]. And T is the temperature and k is the thermal conductivity [W / mK]. k can be represented by a · c _p · ρ, a is thermal diffusivity [cm ² / S], c _p is specific heat [J / gK], and ρ is density [g / cm ³ ].

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

Here, the lower electrode 120 disposed between the lower substrate 110 and the P-type thermoelectric leg 130 and the N-type thermoelectric leg 140, and the upper substrate 160 and the P-type thermoelectric leg 130 and the N-type The upper electrode 150 disposed between the thermoelectric legs 140 includes at least one of copper (Cu), silver (Ag), aluminum (Al), and nickel (Ni), and has a thickness of 0.01 mm to 0.3 mm. Can be. When the thickness of the lower electrode 120 or the upper electrode 150 is less than 0.01mm, the function as the electrode may be degraded, the electrical conduction performance may be lowered, and if the thickness exceeds 0.3mm, the conduction efficiency may be lowered due to the increase in resistance. .

The lower substrate 110 and the upper substrate 160 that face each other may be an insulating substrate or a metal substrate. The insulating substrate may be an alumina substrate or a polymer resin substrate having flexibility. Flexible polymer resin substrates are highly permeable, such as polyimide (PI), polystyrene (PS), polymethyl methacrylate (PMMA), cyclic olefin copoly (COC), polyethylene terephthalate (PET), and resin Various insulating resin materials, such as plastics, can be included. The metal substrate may include Cu, Cu alloy, or Cu—Al alloy, and the thickness may be 0.1 mm to 0.5 mm. If the thickness of the metal substrate is less than 0.1 mm or more than 0.5 mm, the heat dissipation characteristics or the thermal conductivity may be too high, so that the reliability of the thermoelectric element may be lowered. In addition, when the lower substrate 110 and the upper substrate 160 are metal substrates, the dielectric layer 170 is disposed between the lower substrate 110 and the lower electrode 120 and between the upper substrate 160 and the upper electrode 150, respectively. This can be further formed. The dielectric layer 170 includes a material having a thermal conductivity of 5 to 10 W / K, and may be formed to a thickness of 0.01 mm to 0.15 mm. When the thickness of the dielectric layer 170 is less than 0.01 mm, insulation efficiency or withstand voltage characteristics may be lowered, and when the thickness of the dielectric layer 170 is greater than 0.15 mm, thermal conductivity may be lowered to reduce heat radiation efficiency.

In this case, sizes of the lower substrate 110 and the upper substrate 160 may be formed differently. For example, the volume, thickness, or area of one of the lower substrate 110 and the upper substrate 160 may be greater than the volume, thickness, or area of the other. Thereby, the heat absorbing performance or heat dissipation performance of a thermoelectric element can be improved.

In addition, a heat radiation pattern, for example, an uneven pattern may be formed on at least one surface of the lower substrate 110 and the upper substrate 160. Thereby, the heat dissipation performance of a thermoelectric element can be improved. When the uneven pattern is formed on the surface in contact with the P-type thermoelectric leg 130 or the N-type thermoelectric leg 140, the bonding characteristics between the thermoelectric leg and the substrate can also be improved.

Meanwhile, the P-type thermoelectric leg 130 or the N-type thermoelectric leg 140 may have a cylindrical shape, a polygonal pillar shape, an elliptical pillar shape, or the like.

According to an embodiment of the present invention, the P-type thermoelectric leg 130 or the N-type thermoelectric leg 140 may be formed to have a wide width of the portion to be bonded to the electrode.

Referring to FIG. 3, the thermoelectric leg 130 is disposed at a position opposite to the first device portion 132 having a first cross-sectional area and the first device portion 132, and having a second cross-sectional area 136. And a connection part 134 connecting the first device part 132 and the second device part 136 and having a third cross-sectional area. At this time, the cross-sectional area in any region in the horizontal direction of the connecting portion 134 may be formed smaller than the first cross-sectional area or the second cross-sectional area.

As such, when the cross-sectional areas of the first element portion 132 and the second element portion 136 are formed larger than the cross-sectional areas of the connection portion 134, the first element portion 132 and the second element are made of the same amount of material. The temperature difference T between the units 136 may be large. Accordingly, since the amount of free electrons moving between the hot side and the cold side increases, the amount of power generation increases, and the exothermic efficiency or cooling efficiency increases.

In this case, the width B of the cross section having the longest width among the horizontal cross sections of the connecting portion 134 and the width A or the larger cross section among the horizontal cross sections of the first device portion 132 and the second device portion 136. The ratio between C) may be 1: (1.5-4). Thereby, power generation efficiency, heat generation efficiency, or cooling efficiency can be improved.

The first device part 132, the second device part 136, and the connection part 134 may be integrally formed using the same material.

The thermoelectric leg according to an embodiment of the present invention 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. As a result, it is possible to prevent loss of material and to improve electrical conduction characteristics.

Referring to FIG. 4, a material including a semiconductor material is prepared in the form of a paste, and then coated on a substrate 1110 such as a sheet or a film to form a semiconductor layer 1120. Accordingly, one unit member 1100 may be formed.

A plurality of unit members 1100a, 1100b, and 1100c may be stacked to form the stacked structure 1200, and the unit thermoelectric legs 1300 may be obtained by cutting the stacked structures 1200.

As such, the unit thermoelectric leg 1300 may be formed by a structure in which a plurality of unit members 1100 having the semiconductor layer 1120 formed on the substrate 1110 are stacked.

Here, the process of applying the paste on the substrate 1110 may be performed in various ways. For example, it can be done by a tape casting method. Tape casting method is a slurry by mixing a fine semiconductor material powder with at least one selected from an aqueous or non-aqueous solvent, binder, plasticizer, dispersant, defoamer and surfactant After the preparation in the form (slurry), it is a method of molding on a moving blade (blade) or a moving substrate. In this case, the substrate 1110 may be a film, a sheet, or the like having a thickness of 10 μm to 100 μm, and the P-type thermoelectric material or the N-type thermoelectric material for manufacturing the bulk type device may be applied as it is.

The step of arranging the unit members 1100 in a plurality of layers may be performed by pressing at a temperature of 50 to 250 ° C., and the number of unit members 1100 to be stacked may be, for example, 2 to 50. have. Thereafter, it may be cut into a desired shape and size, and a sintering process may be added.

The unit thermoelectric leg 1300 manufactured as described above may secure uniformity in thickness, shape, and size, and may be advantageously thinned and may reduce material loss.

The unit thermoelectric leg 1300 may have a cylindrical shape, a polygonal column shape, an elliptical column shape, or the like, and may be cut into a shape as illustrated in FIG. 4D.

Meanwhile, in order to manufacture a thermoelectric leg having a stacked structure, a conductive layer may be further formed on one surface of the unit member 1100.

Referring to FIG. 5, the conductive layer C may be formed on an opposite side of the substrate 1110 on which the semiconductor layer 1120 is formed, and may be patterned to expose a portion of the surface of the substrate 1110.

5 shows various modifications of the conductive layer C according to the embodiment of the present invention. As shown in FIGS. 5A and 5B, a mesh type structure including closed opening patterns c1 and c2, or as shown in FIGS. 5C and 5D, Various modifications may be made to a line type structure including the open opening patterns c3 and c4.

The conductive layer (C) can increase the adhesive force between the unit members in the unit thermoelectric leg formed in a laminated structure of the unit member, lower the thermal conductivity between the unit members, it is possible to improve the electrical conductivity. The conductive layer C may be a metal material, for example, Cu, Ag, Ni, or the like.

Meanwhile, the unit thermoelectric leg 1300 may be cut in the direction as shown in FIG. 6. According to this structure, it is possible to reduce the thermal conductivity in the vertical direction and to improve the electrical conductivity, thereby increasing the cooling efficiency.

According to one embodiment of the present invention, in order to ensure a stable coupling between the thermoelectric leg and the electrode, to form a metal layer on both sides of the thermoelectric leg.

7 is a cross-sectional view of a thermoelectric leg according to an embodiment of the present invention, FIG. 8 (a) is a schematic diagram of the thermoelectric leg of FIG. 7, and FIG. 8 (b) is a thermoelectric including the thermoelectric leg of FIG. 8 (a). A cross-sectional view of the device.

7, 8 (a) and 8 (b), the thermoelectric leg 700 according to an embodiment of the present invention is disposed on one side of the thermoelectric material layer 710, the thermoelectric material layer 710 The first plating layer 720, the second plating layer 730 disposed on the other surface disposed to face one side of the thermoelectric material layer 710, between the thermoelectric material layer 710 and the first plating layer 720, and the thermoelectric material The first bonding layer 740 and the second bonding layer 750 disposed between the layer 710 and the second plating layer 730, respectively, and disposed on the first plating layer 720 and the second plating layer 730, respectively. And a first metal layer 760 and a second metal layer 770.

That is, the thermoelectric leg 700 according to an embodiment of the present invention may include a thermoelectric material layer 710, a first metal layer disposed on one surface of the thermoelectric material layer 710 and the other surface opposite to the one surface. 760 and the second metal layer 770, between the thermoelectric material layer 710 and the first metal layer 760, between the first bonding layer 740 and the thermoelectric material layer 710 and the second metal layer 770. The second bonding layer 750 disposed, and the first plating layer 720 and the second metal layer 770 and the second bonding layer 750 disposed between the first metal layer 760 and the first bonding layer 740. The second plating layer 730 is disposed between. In this case, the thermoelectric material layer 710 and the first bonding layer 740 may directly contact each other, and the thermoelectric material layer 710 and the second bonding layer 750 may directly contact each other. The first bonding layer 740 and the first plating layer 720 may directly contact each other, and the second bonding layer 750 and the second plating layer 730 may directly contact each other. In addition, the first plating layer 720 and the first metal layer 760 may directly contact each other, and the second plating layer 730 and the second metal layer 770 may directly contact each other.

The thermoelectric material layer 710 may include bismuth (Bi) and tellurium (Te), which are semiconductor materials. The thermoelectric material layer 710 may have the same material or shape as the P-type thermoelectric leg 130 or the N-type thermoelectric leg 140 described with reference to FIGS. 1 to 6.

The first metal layer 760 and the second metal layer 770 may be selected from copper (Cu), a copper alloy, aluminum (Al), and an aluminum alloy, and may be 0.1 to 0.5 mm, preferably 0.2 to 0.3 mm. It may have a thickness. The thermal expansion coefficients of the first metal layer 760 and the second metal layer 770 are similar to or larger than those of the thermoelectric material layer 710, and thus, the first metal layer 760 and the second metal layer 770 may be different from each other. Since compressive stress is applied at the interface between the thermoelectric material layers 710, cracking or peeling can be prevented. In addition, since the bonding force between the first metal layer 760 and the second metal layer 770 and the

electrodes

120 and 150 is high, the thermoelectric leg 700 may be stably coupled with the

electrodes

120 and 150.

Next, the first plating layer 720 and the second plating layer 730 may each include at least one of Ni, Sn, Ti, Fe, Sb, Cr, and Mo, 1 to 20㎛, preferably 1 to It may have a thickness of 10 μm. Since the first plating layer 720 and the second plating layer 730 prevent a reaction between Bi or Te, which is a semiconductor material in the thermoelectric material layer 710, and the first metal layer 760 and the second metal layer 770, In addition to preventing performance degradation, oxidation of the first metal layer 760 and the second metal layer 770 may be prevented.

In this case, the first bonding layer 740 and the second bonding layer 750 may be disposed between the thermoelectric material layer 710 and the first plating layer 720, and between the thermoelectric material layer 710 and the second plating layer 730. Can be. In this case, the first bonding layer 740 and the second bonding layer 750 may include Te. For example, the first bonding layer 740 and the second bonding layer 750 are at least one of Ni-Te, Sn-Te, Ti-Te, Fe-Te, Sb-Te, Cr-Te, and Mo-Te. It may include. According to an embodiment of the present invention, the thickness of each of the first bonding layer 740 and the second bonding layer 750 may be 0.5 to 100 μm, preferably 1 to 50 μm. Referring to FIG. 9, which is a graph showing a resistance change rate according to the thickness of the bonding layer, it can be seen that the resistance change rate increases as the thickness of the bonding layer increases. In particular, when the thickness of the bonding layer exceeds 100㎛, the rate of change of resistance increases rapidly, and as a result may adversely affect the thermoelectric performance of the thermoelectric element. On the other hand, when controlling the thickness of a bonding layer to 100 micrometers or less, it is possible to limit a resistance change rate to 2% or less.

In general, among the semiconductor materials included in the thermoelectric material layer 710, Te is the first plating layer 720 and the second plating layer 730 including at least one of Ni, Sn, Ti, Fe, Sb, Cr, and Mo. Easy to spread. When Te in the thermoelectric material layer 710 is diffused into the first plating layer 720 and the second plating layer 730, the boundary between the thermoelectric material layer 710, the first plating layer 720, and the second plating layer 730 may be adjusted. Compared with Te, a region in which Bi is distributed (hereinafter, referred to as Bi rich region) may be generated. Due to the Bi rich region, the resistance in the thermoelectric leg 700 is increased, and as a result, performance of the thermoelectric element may be degraded.

However, according to the embodiment of the present invention, the first bonding layer 740 and the second bonding layer 750 including Te between the thermoelectric material layer 710 and the first plating layer 720 and the second plating layer 730. ) May be disposed in advance to prevent Te in the thermoelectric material layer 710 from being diffused into the first plating layer 720 and the second plating layer 730. As a result, it is possible to prevent the occurrence of the Bi rich region.

Accordingly, the Te content from the center plane of the thermoelectric material layer 710 to the interface between the thermoelectric material layer 710 and the first bonding layer 740 is higher than the Bi content, and the thermoelectric material from the center plane of the thermoelectric material layer 710. The Te content to the interface between the layer 710 and the second bonding layer 750 is higher than the Bi content. Then, the Te content or the thermoelectric material layer from the center surface of the thermoelectric material layer 710 at a predetermined point in the interface between the thermoelectric material layer 710 and the first bonding layer 740 from the center surface of the thermoelectric material layer 710. The Te content at a predetermined point in the interface between the 710 and the second bonding layer 750 may be 0.8 to 1 times the Te content of the center surface of the thermoelectric material layer 710. For example, the Te content at a predetermined point within a thickness of 100 μm in the direction of the center plane of the thermoelectric material layer 710 from the interface between the thermoelectric material layer 710 and the first bonding layer 740 is the thermoelectric material layer 710. It may be 0.8 to 1 times compared to the Te content of the central plane of.

In addition, the content of Te in the first bonding layer 740 or the second bonding layer 750 may be 0.8 to 1 times the content of Te in the thermoelectric material layer 710. In addition, a surface in contact with the first plating layer 720 in the first bonding layer 740, that is, an interface between the first plating layer 720 and the first bonding layer 740 or a second plating layer in the second bonding layer 750 ( The content of Te at the surface in contact with 730, that is, the interface between the second plating layer 730 and the second bonding layer 750, is in contact with the first bonding layer 740 in the thermoelectric material layer 710, that is, the thermoelectric material. Interface between the layer 710 and the first bonding layer 740 At the surface in contact with the second bonding layer 750 in the thermoelectric material layer 710, that is, at the interface between the thermoelectric material layer 710 and the second bonding layer 750. It may be 0.8 to 1 times the content of Te. The Te content of the interface between the thermoelectric material layer 710 and the first bonding layer 740 or the interface between the thermoelectric material layer 710 and the second bonding layer 750 is Te in the center plane of the thermoelectric material layer 710. It may be 0.8 to 1 times the content.

Referring to FIG. 10, a metal substrate is prepared (S100). Here, the metal substrate may be the first metal layer 760 and the second metal layer 770 of the thermoelectric leg 700 of FIG. 7. That is, the metal substrate may be selected from copper (Cu), copper alloys, aluminum (Al) and aluminum alloys.

Next, a Ni plating layer is formed on one surface of the metal substrate (S110). Here, the plating layer may be formed of not only Ni but also at least one metal of Sn, Ti, Fe, Sb, Cr, and Mo. In addition, the plating layer may be formed on both sides of the metal substrate. In the present specification, a layer including at least one metal of Ni, Sn, Ti, Fe, Sb, Cr, and Mo is represented by a plating layer, but this is not only a layer formed by plating, but also a layer deposited by various techniques. It may mean to include.

Next, a bonding layer containing Te is formed on the plating layer (S120). To this end, after applying a slurry mixed with Te powder and alcohol on the plating layer, it is heat-treated at a temperature of 300 to 400 ℃. Accordingly, the Te coated on the plating layer diffuses toward the plating layer and reacts with Ni to form a bonding layer. At this time, Ni-Te bonding layer is formed by the thickness reacted with Te. Here, the bonding layer may be formed by reacting Te with at least one metal of Sn, Ti, Fe, Sb, Cr, and Mo as well as Ni. Thereafter, the Te powder remaining without reacting on the bonding layer is removed by washing.

Alternatively, the bonding layer may be formed by vacuum depositing a Te source on the plating layer. That is, the bonding layer may be formed by Te deposited on the plating layer diffused toward the plating layer and reacting with Ni. Alternatively, the bonding layer may be formed by vacuum depositing a Ni-Te source on the plating layer. Alternatively, the bonding layer may omit step S110 of forming a plating layer, and directly form a Ni-Te vacuum deposition layer by directly introducing a Ni-Te source onto the metal substrate.

Alternatively, the bonding layer may be formed to a desired thickness by forming a plating layer with a predetermined thickness in step S110 and then adding Te ions into the plating solution.

Next, a thermoelectric material including Bi and Te is disposed between two metal substrates / plating layers / bonding layers formed through S100 to S120, and then pressed and sintered (S130). Here, the metal substrate / plating layer / bonding layer manufactured through the steps S100 to S120 may be cut according to a predetermined size, disposed on both sides of the thermoelectric material, and then pressed and sintered. Alternatively, after the metal substrate / plating layer / bonding layer is manufactured to a predetermined size through steps S100 to S120, the metal substrate / plating layer / bonding layer is manufactured to a predetermined size by repeating steps S100 to S120, and the amount of thermoelectric material After arrange | positioning to a surface, you may pressurize and sinter.

In this case, the pressing and sintering may be performed by a hot press process. The hot press process may be a spark plasma sintering (SPS) process that generates joule heat by applying a pulse current from a direct current (DC) power source. Since the discharge plasma sintering process proceeds through a process in which high energy promotes thermal diffusion between particles due to an instantaneous discharge phenomenon, it is easy to control the sintered microstructure having excellent sinter control, that is, less grain growth. In this case, the thermoelectric material may be sintered together with the amorphous ribbon. When the powder for thermoelectric legs is sintered together with the amorphous ribbon, the electrical conductivity becomes high, so that high thermoelectric performance can be obtained. In this case, the amorphous ribbon may be an Fe-based amorphous ribbon. For example, the amorphous ribbon may be disposed on the side of the thermoelectric leg and then sintered. Accordingly, electrical conductivity may be increased along the side of the thermoelectric leg. For this purpose, the amorphous ribbon can be arranged to surround the wall surface of the mold, followed by filling and sintering the thermoelectric material. At this time, the amorphous ribbon may be disposed on the side of the thermoelectric material layer of the thermoelectric leg.

FIG. 11 is a diagram schematically illustrating a Te content distribution in a thermoelectric leg manufactured according to the method of FIG. 10, and FIG. 12 is a graph analyzing composition distribution for each region in the thermoelectric leg manufactured according to the method of FIG. 10. 13 is a diagram schematically illustrating a Te content distribution in a thermoelectric leg manufactured according to a comparative example, and FIG. 14 is a graph analyzing composition distribution for each region in the thermoelectric leg manufactured according to the comparative example.

11 to 12, in the embodiment, after the plating layers 720 and 730 are formed on the aluminum (Al)

substrates

760 and 770 having a thickness of about 0.2 to 0.3 mm, the Te layers are formed on the plating layers 720 and 730. By applying heat treatment to form the bonding layers 740 and 750, and placing a thermoelectric material 710 of about 1.6 mm thickness including Bi and Te between the two aluminum substrates / plating layers / bonding layers, and then pressing and Sintered. Through the process of applying Te on the plating layer and heat treatment, the coated Te diffused toward Ni on the surface of the plating layer to react with Ni, thereby forming a bonding layer including Ni-Te. At this time, the thickness of the plating layer was formed to about 1 to 10㎛, the thickness of the bonding layer was formed to about 40㎛.

13 to 14, in the comparative example, after forming the plating layers 820 and 830 on the aluminum (Al)

substrates

860 and 870 having a thickness of about 0.2 to 0.3 mm, the two aluminum substrates / plating layers were formed. About 1.6 mm thick thermoelectric material containing Bi and Te was placed in, pressed and sintered. Through the pressing and sintering process, Te in the thermoelectric material diffused toward Ni on the surface of the plating layer to react with Ni, thereby forming

bonding layers

840 and 850 including Ni-Te. At the edge of the thermoelectric material, Te was diffused toward the plating layer, thereby forming a Bi rich layer having a relatively high Bi content.

11 to 14, the content of Te in the first plating layers 720 and 820 or the second plating layers 730 and 830 may include the content of Te in the thermoelectric material layers 710 and 810 and the first bonding layer 740. It can be seen that the content is lower than the content of Te in the 840 or the second bonding layers 750 and 850.

11 to 12, the Te content of the center plane C of the thermoelectric material layer 710 is defined as the interface between the thermoelectric material layer 710 and the first bonding layer 740 or the thermoelectric material layer 710 and the first surface. It can be seen that the same or similar to the Te content of the interface between the two bonding layer 750. In the present specification, the center plane C means the center plane C itself of the thermoelectric material layer 710, or the center plane C adjacent to the center plane C and the center plane C within a predetermined distance. It may mean including a peripheral area. The boundary surface may mean the boundary surface itself, or may include a boundary region adjacent to the boundary surface within a predetermined distance from the boundary surface. For example, the Te content of the center plane C of the thermoelectric material layer 710 may be an interface between the thermoelectric material layer 710 and the first bonding layer 740 or the thermoelectric material layer 710 and the second bonding layer 750. It may be 0.8 to 1 times, preferably 0.85 to 1 times, more preferably 0.9 to 1 times, more preferably 0.95 to 1 times the Te content of the interface between the). Here, the content may be a weight ratio.

In addition, the Bi content of the center plane C of the thermoelectric material layer 710 is the interface between the thermoelectric material layer 710 and the first bonding layer 740 or between the thermoelectric material layer 710 and the second bonding layer 750. It can be seen that the same or similar to the Bi content of the interface. Accordingly, the interface between the thermoelectric material layer 710 and the first bonding layer 740 or the interface between the thermoelectric material layer 710 and the second bonding layer 750 from the center plane C of the thermoelectric material layer 710. Since the content of Te is higher than the content of Bi until now, at the periphery of the interface between the thermoelectric material layer 710 and the first bonding layer 740 or at the periphery of the interface between the thermoelectric material layer 710 and the second bonding layer 750. There is no section in which the Bi content reverses the Te content. For example, the Bi content of the center plane C of the thermoelectric material layer 710 is an interface between the thermoelectric material layer 710 and the first bonding layer 740 or the thermoelectric material layer 710 and the second bonding layer 750. ) May be 0.8 to 1 times, preferably 0.85 to 1 times, more preferably 0.9 to 1 times, more preferably 0.95 to 1 times the Bi content of the interface between. Here, the content may be a weight ratio.

In contrast, according to FIGS. 13 to 14, the interface between the thermoelectric material layer 810 and the first bonding layer 840 or the thermoelectric material layer 810 is lower than the Te content of the center plane C of the thermoelectric material layer 810. It can be seen that the Te content of the interface between the second bonding layer 850 is low. This is because Te, a semiconductor material in the thermoelectric material layer 810, is naturally diffused into the first plating layer 820 and the second plating layer 830 to react with the first plating layer 820 and the second plating layer 830. . Accordingly, the content of Te decreases from the center surface C of the thermoelectric material layer 810 toward the edge, and the thermoelectric material from the point diffused to react with the first plating layer 820 and the second plating layer 830. The Bi rich layer is formed to the boundary between the layer 810, the first plating layer 820, and the second plating layer 830. The Bi-rich layer may be formed to a thickness of 200㎛ or less. That is, although the content of Te is higher than the content of Bi around the center plane C of the thermoelectric material layer 710, the interface between the thermoelectric material layer 710 and the first bonding layer 740 or the thermoelectric material layer 710 ) And a section in which the Bi content reverses the Te content around the interface between the second bonding layer 750 and the second bonding layer 750. The Bi rich layer is a region in which an appropriate stoichiometric ratio between Bi and Te, which are basic constituents of the thermoelectric material, is destroyed, and may be formed to an interface between the thermoelectric material 810 and the bonding layers 840 and 850. The thicker the bi-rich layer, the higher the resistance change rate, which can be a major factor in increasing the resistance inside the thermoelectric leg.

11 to 12, it can be seen that the content of Te in the first bonding layer 740 or the second bonding layer 750 is the same as or similar to the content of Te in the thermoelectric material layer 710. For example, the content of Te in the first bonding layer 740 or the second bonding layer 750 is 0.8 to 1 times, preferably 0.85 to 1 times, more preferably, the content of Te in the thermoelectric material layer 710. Preferably 0.9 to 1 times, more preferably 0.95 to 1 times. Here, the content may be a weight ratio. For example, when the content of Te in the thermoelectric material layer 710 is 50wt%, the content of Te in the first bonding layer 740 or the second bonding layer 750 is 40 to 50wt%, preferably 42.5 to 50 wt%, more preferably 45 to 50 wt%, more preferably 47.5 to 50 wt%. In addition, the content of Te in the first bonding layer 740 or the second bonding layer 750 may be greater than that of Ni. The content of Te is uniformly distributed in the first bonding layer 740 or the second bonding layer 750, while the Ni content is the thermoelectric material layer in the first bonding layer 740 or the second bonding layer 750. The closer to the 710 direction, the smaller it may be.

On the other hand, a part of the material included in each layer may be detected from within the adjacent layer by diffusing from the interface between each layer and the adjacent layer. For example, a portion of the material included in the metal layer may be detected in the plating layer by being diffused from the interface between the metal layer and the plating layer, and a portion of the material included in the plating layer may be diffused from the interface between the plating layer and the bonding layer and detected in the bonding layer. Some of the materials included in the bonding layer may diffuse from an interface between the bonding layer and the thermoelectric material layer and be detected in the thermoelectric material layer. In addition, a part of the material included in the plating layer may be detected in the metal layer by being diffused from the interface between the metal layer and the plating layer, and a part of the material included in the bonding layer may be detected in the plating layer by being diffused from the interface between the plating layer and the bonding layer. A portion of the material included in the thermoelectric material layer may diffuse from an interface between the bonding layer and the thermoelectric material layer and be detected in the bonding layer.

On the other hand, according to FIGS. 13 to 14, it can be seen that the content of Te in the first bonding layer 840 or the second bonding layer 850 is lower than the content of Te in the thermoelectric material layer 810. 11 to 12, since Te is coated on the first plating layer 720 or the second plating layer 730 to form the first bonding layer 740 or the second bonding layer 750, the content of Te is increased. Although it remains constant, in FIGS. 13 to 14, the Te in the thermoelectric material layer 810 naturally diffuses to react with the first plating layer 820 or the second plating layer 830.

11 to 12, the content of Te at the interface between the first plating layer 720 and the first bonding layer 740 or at the interface between the second plating layer 730 and the second bonding layer 750 is a thermoelectric material. It can be seen that the content of Te is equal to or similar to the interface between the layer 710 and the first bonding layer 740 or the interface between the thermoelectric material layer 710 and the second bonding layer 750. For example, the content of Te at the interface between the first plating layer 720 and the first bonding layer 740 or at the interface between the second plating layer 730 and the second bonding layer 750 may correspond to the thermoelectric material layer 710. 0.8 to 1 times, preferably 0.85 to 1 times, more preferably 0.9, the content of Te at the interface between the first bonding layer 740 or at the interface between the thermoelectric material layer 710 and the second bonding layer 750. To 1 times, more preferably 0.95 to 1 times. Here, the content may be a weight ratio.

In contrast, according to FIGS. 13 to 14, the content of Te at the interface between the first plating layer 820 and the first bonding layer 840 or at the interface between the second plating layer 830 and the second bonding layer 850 is determined by thermoelectric. It can be seen that the content of Te is lower than the interface between the material layer 810 and the first bonding layer 840 or the interface between the thermoelectric material layer 810 and the second bonding layer 850. 11 to 12, since Te is coated on the first plating layer 720 or the second plating layer 730 to form the first bonding layer 740 or the second bonding layer 750, the content of Te is increased. Although it remains constant, in FIGS. 13 to 14, the Te in the thermoelectric material layer 810 naturally diffuses to react with the first plating layer 820 or the second plating layer 830.

Table 1 is a table comparing the electrical resistance of the P-type thermoelectric legs according to the Examples and Comparative Examples.

구분division	사이즈size	저항resistance
실시예Example	4mm4mm5mm4mm * 4mm * 5mm	3.310^-3Ω3.3 10 ^-3 Ω
실시예Example	4mm4mm1.2mm4mm * 4mm * 1.2mm	0.810^-3Ω0.8 10 ^-3 Ω
비교예Comparative example	4mm4mm5mm4mm * 4mm * 5mm	4.510^-3Ω4.5 10 ^-3 Ω
비교예Comparative example	4mm4mm1.2mm4mm * 4mm * 1.2mm	2.0510^-3Ω2.05 10 ^-3 Ω

Referring to Table 1, it can be seen that the electrical resistance of the thermoelectric legs manufactured according to the embodiment, that is, 11 to 12, compared to the comparative example, that is, the thermoelectric legs manufactured according to FIGS. In particular, when the size of the thermoelectric leg is miniaturized, it can be seen that the rate of decrease in electrical resistance becomes larger. This is because the Te content in the thermoelectric legs is evenly distributed, and the formation of the Bi rich layer is suppressed, so that the decrease in the resistance of the thermoelectric legs can prevent the decrease in the electrical conductivity of the thermoelectric elements, thereby increasing the Seebeck index of the thermoelectric elements. Can be.

Table 2 is a table comparing the tensile strength of each thermoelectric leg of the size of 4mm * 4mm * 5mm according to the Examples and Comparative Examples.

인장강도The tensile strength	N 형 (Kgf/mm²)N type (Kgf / mm ² )	P형 (Kgf/mm²)P type (Kgf / mm ² )
비교예Comparative example	0.650.65	2.452.45
실시예Example	1.651.65	2.552.55

Referring to Table 2, it can be seen that the comparative example, that is, the tensile strength of the thermoelectric legs prepared according to the embodiment, that is, according to Figures 11 to 12 is greater than the thermoelectric legs prepared according to Figures 13 to 14. Tensile strength refers to the interlayer bonding force in the thermoelectric leg, which artificially bonded the metal wires to the first and second metal layers on both sides of the manufactured thermoelectric leg, respectively, and pulled the joined metal wires in opposite directions. When the maximum load to withstand. Since the greater the tensile strength, the higher the interlayer bonding strength in the thermoelectric leg, it is possible to prevent a problem that at least some of the metal layer, the plating layer, the bonding layer, and the thermoelectric material layer in the thermoelectric leg are dropped from the adjacently disposed layer when the thermoelectric element is driven. The thermoelectric element according to the embodiment of the present invention may act on the apparatus for power generation, the apparatus for cooling, the apparatus for heating, and the like. Specifically, the thermoelectric device according to the embodiment of the present invention mainly includes optical communication modules, sensors, medical devices, measuring devices, aerospace industry, refrigerators, chillers, automobile ventilation sheets, cup holders, washing machines, dryers, and wine cellars. It can be applied to water purifier, sensor power supply, thermopile and the like.

Here, an example in which a thermoelectric device according to an embodiment of the present invention is applied to a medical device includes a polymer chain reaction (PCR) device. PCR equipment is a device for amplifying DNA to determine the DNA sequence, precise temperature control is required, and a thermal cycle (thermal cycle) equipment is required. To this end, a Peltier-based thermoelectric device may be applied.

Another example in which a thermoelectric device according to an embodiment of the present invention is applied to a medical device is a photo detector. Here, the photo detector includes an infrared / ultraviolet detector, a charge coupled device (CCD) sensor, an X-ray detector, a thermoelectric thermal reference source (TTRS), and the like. Peltier-based thermoelectric elements may be applied for cooling the photo detector. As a result, it is possible to prevent a change in wavelength, a decrease in power, a decrease in resolution, etc. due to a temperature rise inside the photodetector.

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

Another example where the thermoelectric device according to an embodiment of the present invention is applied to a medical device is an artificial heart. Thus, power can be supplied to the artificial heart.

Examples of applications of the thermoelectric device according to an embodiment of the present invention to the aerospace industry include a star tracking system, a thermal imaging camera, an infrared / ultraviolet detector, a CCD sensor, a hubble space telescope, and a TTRS. Accordingly, the temperature of the image sensor can be maintained.

Another example where the thermoelectric device according to the embodiment of the present invention is applied to the aerospace industry includes a cooling device, a heater, a power generation device, and the like.

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

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims

Thermoelectric material layer comprising Bi and Te,

A first metal layer and a second metal layer respectively disposed on one side and the other side of the thermoelectric material layer;

A second bonding layer disposed between the thermoelectric material layer and the first metal layer and disposed between the first bonding layer including the Te and the thermoelectric material layer and the second metal layer, and including the Te;

A first plating layer disposed between the first metal layer and the first bonding layer, and a second plating layer disposed between the second metal layer and the second bonding layer,

The thermoelectric material layer is disposed between the first metal layer and the second metal layer,

The Te content is higher than the Bi content from the center surface of the thermoelectric material layer to the interface between the thermoelectric material layer and the first bonding layer,

And the Te content is higher than the Bi content from the center plane of the thermoelectric material layer to the interface between the thermoelectric material layer and the second bonding layer.
The method of claim 1,

And the Te content at a predetermined point in the interface between the thermoelectric material layer and the first bonding layer from the center surface of the thermoelectric material layer is 0.8 to 1 times the Te content of the center surface of the thermoelectric material layer.
The method of claim 2,

The Te content at a predetermined point within 100 μm thickness in the direction of the center surface of the thermoelectric material layer from the interface between the thermoelectric material layer and the first bonding layer is 0.8 to 1 times the Te content of the center surface of the thermoelectric material layer. Thermoelectric legs.
The method of claim 2,

At least one of the first plating layer and the second plating layer each of the thermoelectric legs including at least one metal of Ni, Sn, Ti, Fe, Sb, Cr and Mo.
The method of claim 4, wherein

At least one of the first bonding layer and the second bonding layer further comprises at least one metal selected from the first plating layer and the second plating layer.
The method of claim 5,

At least one of the first metal layer and the second metal layer is selected from copper, a copper alloy, aluminum and an aluminum alloy.
The method of claim 2,

The thickness of the first plating layer is a thermoelectric leg of 1㎛ 20㎛.
The method of claim 1,

The thermoelectric material layer and the first bonding layer are in direct contact with each other,

The first bonding layer and the first plating layer are in direct contact with each other,

And the first plating layer and the first metal layer are in direct contact with each other.
First substrate,

A plurality of P-type thermoelectric legs and a plurality of N-type thermoelectric legs disposed alternately on the first substrate,

A second substrate disposed on the plurality of P-type thermoelectric legs and the plurality of N-type thermoelectric legs, and

A plurality of electrodes connecting the plurality of P-type thermoelectric legs and the plurality of N-type thermoelectric legs in series,

The plurality of P-type thermoelectric legs and the plurality of N-type thermoelectric legs are respectively

Thermoelectric material layer comprising Bi and Te,

A first metal layer and a second metal layer respectively disposed on one side and the other side of the thermoelectric material layer;

A second bonding layer disposed between the thermoelectric material layer and the first metal layer and disposed between the first bonding layer including the Te and the thermoelectric material layer and the second metal layer, and including the Te;

A first plating layer disposed between the first metal layer and the first bonding layer, and a second plating layer disposed between the second metal layer and the second bonding layer,

The thermoelectric material layer is disposed between the first metal layer and the second metal layer,

The Te content is higher than the Bi content from the center surface of the thermoelectric material layer to the interface between the thermoelectric material layer and the first bonding layer,

The Te content from the center surface of the thermoelectric material layer to the interface between the thermoelectric material layer and the second bonding layer is higher than the Bi content.
The method of claim 9,

The Te content at a predetermined point in the interface between the thermoelectric material layer and the first bonding layer from the center surface of the thermoelectric material layer is 0.8 to 1 times the Te content of the center surface of the thermoelectric material layer.