thermoelectric element

Abstract

A thermoelectric element according to one embodiment of the present invention includes a substrate, a first insulating layer disposed on the substrate, a second insulating layer disposed on the first insulating layer and having an area smaller than that of the first insulating layer, a plurality of first electrodes disposed on the second insulating layer, a plurality of semiconductor structures disposed on each of the plurality of first electrodes, and a plurality of second electrodes disposed on the plurality of semiconductor structures, wherein the second insulating layer includes an overlapping region where the plurality of first electrodes, the plurality of second electrodes, and the plurality of semiconductor structures are vertically overlapped, and a protruding pattern protruding toward a first outer side of the substrate in the overlapping region.

Description

[Technical Field]

[0001] The present invention relates to a thermoelectric element. [Background technology]

[0002] Thermoelectricity is a phenomenon that occurs due to the movement of electrons and holes within a material, and refers to the direct energy conversion between heat and electricity.

[0003] A thermoelectric element is a general term for elements that use the thermoelectric phenomenon, and has a structure in which a P-type thermoelectric material and an N-type thermoelectric material are joined between metal electrodes to form a PN junction pair.

[0004] Thermoelectric elements can be classified into elements that use a temperature change in electrical resistance, elements that use the Seebeck effect, which is a phenomenon in which an electromotive force is generated by a temperature difference, and elements that use the Peltier effect, which is a phenomenon in which heat is absorbed or generated by an electric current.

[0005] Thermoelectric elements are widely used in home appliances, electronic components, communication components, etc. For example, thermoelectric elements can be used in cooling devices, heating devices, power generation devices, etc. This has led to higher demands for thermoelectric performance of thermoelectric elements.

[0006] The thermoelectric element includes a substrate, electrodes, and thermoelectric legs, with a plurality of thermoelectric legs arranged in an array between an upper substrate and a lower substrate, a plurality of upper electrodes arranged between the plurality of thermoelectric legs and the upper substrate, and a plurality of lower electrodes arranged between the plurality of thermoelectric legs and the lower substrate.

[0007] During the manufacturing process of a thermoelectric device, the substrate, electrodes, and thermoelectric legs are bonded together in a high-temperature environment, which can cause warping of the substrate due to differences in the thermal expansion coefficients of the materials, which can reduce the long-term reliability, durability, and power generation performance of the thermoelectric device. Summary of the Invention [Problem to be solved by the invention]

[0008] The problem to be solved by the present invention is to provide a thermoelectric element in which the warping phenomenon of the substrate is improved. [Means for solving the problem]

[0009] A thermoelectric element according to one embodiment of the present invention includes a substrate, a first insulating layer disposed on the substrate, a second insulating layer disposed on the first insulating layer and having an area smaller than that of the first insulating layer, a plurality of first electrodes disposed on the second insulating layer, a plurality of semiconductor structures disposed on each of the plurality of first electrodes, and a plurality of second electrodes disposed on the plurality of semiconductor structures, wherein the second insulating layer includes an overlapping region where the plurality of first electrodes, the plurality of second electrodes, and the plurality of semiconductor structures are vertically overlapped, and a protruding pattern protruding from the overlapping region toward a first outer side of the substrate.

[0010] The width of the protruding pattern may be smaller than the width of the overlapping region.

[0011] The protruding pattern and the first outer side of the substrate may be spaced apart from each other.

[0012] A protruding length of the protruding pattern may be longer than a length from the protruding pattern to the first outer side.

[0013] The protruding pattern may include a first protruding pattern and a second protruding pattern spaced apart from each other.

[0014] The separation distance between the first protruding pattern and the second protruding pattern may be 0.9 to 2 times the distance between a second outer side of the substrate perpendicular to the first outer side and the first protruding pattern, and 0.9 to 2 times the distance between a third outer side of the substrate perpendicular to the first outer side and facing the second outer side and the second protruding pattern.

[0015] The display panel may further include a first terminal electrode and a second terminal electrode protruding from the plurality of first electrodes toward the first outer side, and the first terminal electrode and the second terminal electrode may be disposed on the first protruding pattern and the second protruding pattern, respectively.

[0016] The area of ​​each of the first terminal electrode and the second terminal electrode may be larger than the area of ​​each of the plurality of first electrodes.

[0017] The insulating film may further include a sealing member disposed to contact the first insulating layer at the first outer side and to contact the second insulating layer at a fourth outer side opposite the first outer side.

[0018] The second insulating layer may include a first recess and a second recess arranged around the first recess, the plurality of first electrodes may be arranged on the first recesses, and a first vertical distance between the first recess and the substrate may be smaller than a second vertical distance between the second recess and the substrate.

[0019] The first insulating layer may be disposed so as to be spaced apart from at least a portion of an edge of the first substrate.

[0020] The second insulating layer may be disposed so as to be spaced apart from at least a portion of an edge of the second insulating layer.

[0021] The first insulating layer and the second insulating layer may have different compositions.

[0022] The display device may further include an upper substrate disposed on the plurality of second electrodes, the upper substrate not vertically overlapping the protrusion patterns.

[0023] The plurality of first electrodes may include a first electrode group and a second electrode group spaced apart from each other, the plurality of second electrodes may include a third electrode group and a fourth electrode group spaced apart from each other, the first electrode group and the third electrode group overlapping each other in a direction perpendicular to the substrate, and the second electrode group and the fourth electrode group overlapping each other in a direction perpendicular to the substrate.

[0024] The upper substrate may include a first upper substrate disposed on the third electrode group, and a second upper substrate spaced apart from the first upper substrate and disposed on the fourth electrode group. [Effects of the Invention]

[0025] According to the embodiments of the present invention, the warpage phenomenon of the substrate is improved, and a thermoelectric element with high long-term reliability, durability, and power generation performance can be obtained.

[0026] In particular, according to an embodiment of the present invention, a thermoelectric element can be obtained that not only has bonding performance, thermal conductivity performance, and voltage resistance performance but also has an improved substrate warpage phenomenon, by using the structure of the insulating layer and substrate disposed between the substrate and the electrode. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 1 is a cross-sectional view of a thermoelectric element.

[0028] [Figure 2] FIG. 2 is a perspective view of a thermoelectric element.

[0029] [Figure 3] FIG. 3 is a perspective view of a thermoelectric device including a sealing member.

[0030] [Figure 4] FIG. 4 is an exploded perspective view of a thermoelectric element including a sealing member.

[0031] [Figure 5] FIG. 5 is a cross-sectional view of a thermoelectric element according to an embodiment of the present invention.

[0032] [Figure 6] FIG. 6 is a top view of a substrate, an insulating layer, and electrodes included in a thermoelectric element according to one embodiment of the present invention.

[0033] [Figure 7] FIG. 7(a) is an exploded perspective view of a thermoelectric element according to an embodiment of the present invention, and FIG. 7(b) is a perspective view of a thermoelectric element according to an embodiment of the present invention.

[0034] [Figure 8] FIG. 8 is a top view of a substrate, an insulating layer, and electrodes included in a thermoelectric element according to another embodiment of the present invention.

[0035] [Figure 9] FIG. 9 is a perspective view of a thermoelectric device according to another embodiment of the present invention.

[0036] [Figure 10] FIG. 10 is a perspective view of a thermoelectric device according to still another embodiment of the present invention.

[0037] [Figure 11] FIG. 11 is a top view of a substrate, an insulating layer, and electrodes included in a thermoelectric element according to yet another embodiment of the present invention.

[0038] [Figure 12] FIG. 12 shows a joining structure between a heat sink and a second substrate in a thermoelectric module according to an embodiment of the present invention.

[0039] [Figure 13] FIG. 13 shows the simulation results when the upper substrate of the thermoelectric element is a single substrate.

[0040] [Figure 14] FIG. 14 shows the simulation results when the upper substrate of the thermoelectric element is a divided substrate.

[0041] [Figure 15] FIG. 15 shows the simulation results for a model in which the second insulating layer is applied to the entire surface.

[0042] [Figure 16] FIG. 16 shows the results of a simulation using a model in which the second insulating layer is pattern-coated. DETAILED DESCRIPTION OF THE INVENTION

[0043] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0044] However, the technical concept of the present invention is not limited to the described embodiments, but may be embodied in various different forms, and one or more of the components of the embodiments may be selectively combined or substituted within the scope of the technical concept of the present invention.

[0045] Furthermore, unless otherwise clearly defined and described, terms (including technical and scientific terms) used in the embodiments of the present invention may be interpreted in a way that would be commonly understood by a person of ordinary skill in the art to which the present invention belongs, and commonly used terms, such as terms defined in a dictionary, may be interpreted in light of the contextual meaning of the relevant art.

[0046] Furthermore, the terms used in the examples of the present invention are intended to explain the examples and are not intended to limit the present invention.

[0047] In this specification, the singular form can also include the plural form unless otherwise specified in the phrase, and when it is stated as "A and (and) at least one (or more) of B and C," it can include one or more of all possible combinations of A, B, and C.

[0048] Additionally, terms such as first, second, A, B, (a), (b), etc. may be used to describe components of embodiments of the present invention.

[0049] Such terms are used merely to distinguish a component from other components, and do not limit the essence, order, or procedure of the component.

[0050] Furthermore, when a component is described as being "coupled," "coupled," or "connected" to another component, it includes not only the case where the component is directly coupled, coupled, or connected to the other component, but also the case where the component is "coupled," "coupled," or "connected" between the other component and the other component or by another component.

[0051] Furthermore, when something is described as being formed or disposed "above or below" a component, the above or below not only refers to the case where two components are in direct contact with each other, but also refers to the case where one or more other components are formed or disposed between the two components. Furthermore, when something is expressed as "above or below," it can mean not only the upper direction but also the lower direction based on one component.

[0052] Figure 1 is a cross-sectional view of a thermoelectric element, Figure 2 is a perspective view of the thermoelectric element, Figure 3 is a perspective view of the thermoelectric element including a sealing member, and Figure 4 is an exploded perspective view of the thermoelectric element including a sealing member.

[0053] Referring to FIGS. 1 and 2, the thermoelectric device 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 .

[0054] The lower electrode 120 is disposed between the lower substrate 110 and the lower bottom surfaces of the P-type thermoelectric legs 130 and the N-type thermoelectric legs 140, and the upper electrode 150 is disposed between the upper substrate 160 and the upper bottom surfaces of the P-type thermoelectric legs 130 and the N-type thermoelectric legs 140. As a result, 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 and electrically connected between the lower electrode 120 and the upper electrode 150 may form a unit cell.

[0055] For example, when a voltage is applied to the lower electrode 120 and the upper electrode 150 through the lead wires 181 and 182, the substrate in which current flows from the P-type thermoelectric leg 130 to the N-type thermoelectric leg 140 due to the Peltier effect absorbs heat and acts as a cooling part, and the substrate in which current flows from the N-type thermoelectric leg 140 to the P-type thermoelectric leg 130 is heated and can act as a heating part. Alternatively, when a temperature difference is applied between the lower electrode 120 and the upper electrode 150, charges in the P-type thermoelectric leg 130 and the N-type thermoelectric leg 140 move due to the Seebeck effect, generating electricity.

[0056] In Figures 1 to 4, the lead wires 181 and 182 are illustrated as being arranged on the lower substrate 110, but this is not limited to this, and the lead wires 181 and 182 may be arranged on the upper substrate 160, or one of the lead wires 181 and 182 may be arranged on the lower substrate 110 and the other on the upper substrate 160.

[0057] Here, the P-type thermoelectric leg 130 and the N-type thermoelectric leg 140 may be bismuth telluride (Bi-Te)-based thermoelectric legs containing bismuth (Bi) and tellurium (Te) as main materials. The P-type thermoelectric leg 130 may be a bismuth telluride (Bi-Te)-based thermoelectric leg containing at least one of antimony (Sb), nickel (Ni), aluminum (Al), copper (Cu), silver (Ag), lead (Pb), boron (B), gallium (Ga), tellurium (Te), bismuth (Bi), and indium (In). For example, the P-type thermoelectric leg 130 may contain 99 to 99.999 wt% of Bi-Sb-Te as a main raw material, and 0.001 to 1 wt% of at least one of nickel (Ni), aluminum (Al), copper (Cu), silver (Ag), lead (Pb), boron (B), gallium (Ga), and indium (In), based on a total weight of 100 wt%. The N-type thermoelectric leg 140 may be a bismuth telluride (Bi-Te) thermoelectric leg containing at least one of selenium (Se), nickel (Ni), aluminum (Al), copper (Cu), silver (Ag), lead (Pb), boron (B), gallium (Ga), tellurium (Te), bismuth (Bi), and indium (In). For example, the N-type thermoelectric leg 140 may contain 99 to 99.999 wt% of the main raw material Bi-Se-Te, and 0.001 to 1 wt% of at least one of nickel (Ni), aluminum (Al), copper (Cu), silver (Ag), lead (Pb), boron (B), gallium (Ga), and indium (In), based on a total weight of 100 wt%. Accordingly, in this specification, the thermoelectric leg may also be referred to as a semiconductor structure, semiconductor element, semiconductor material layer, conductive semiconductor structure, thermoelectric structure, thermoelectric material layer, thermoelectric material layer, thermoelectric material layer, or the like.

[0058] The P-type thermoelectric legs 130 and the N-type thermoelectric legs 140 may be formed in a bulk or stacked type. Generally, the bulk P-type thermoelectric legs 130 or the bulk N-type thermoelectric legs 140 are obtained by heat-treating a thermoelectric material to produce an ingot, crushing and screening the ingot to obtain a powder for the thermoelectric legs, sintering the powder, and cutting the sintered body. In this case, the P-type thermoelectric legs 130 and the N-type thermoelectric legs 140 may be polycrystalline thermoelectric legs. If the P-type thermoelectric legs 130 and the N-type thermoelectric legs 140 are polycrystalline thermoelectric legs, the strength of the P-type thermoelectric legs 130 and the N-type thermoelectric legs 140 may be increased. The stacked P-type thermoelectric legs 130 or the stacked N-type thermoelectric legs 140 are obtained by applying a paste containing a thermoelectric material to a sheet-like substrate to form unit members, and then stacking and cutting the unit members.

[0059] 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 P-type thermoelectric legs 130 and N-type thermoelectric legs 140 have different electrical conduction characteristics, the height or cross-sectional area of ​​the N-type thermoelectric legs 140 may be formed to be different from the height or cross-sectional area of ​​the P-type thermoelectric legs 130.

[0060] 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.

[0061] Alternatively, the P-type thermoelectric leg 130 or the N-type thermoelectric leg 140 may have a laminated structure. For example, the P-type thermoelectric leg or the N-type thermoelectric leg may be formed by laminating multiple structures in which a semiconductor material is applied to a sheet-like substrate and then cutting the laminate. This may prevent material loss and improve electrical conductivity. Each structure may further include a conductive layer with an opening pattern, which may increase adhesion between the structures, reduce thermal conductivity, and increase electrical conductivity.

[0062] Alternatively, the P-type thermoelectric leg 130 or the N-type thermoelectric leg 140 may be formed to have different cross-sectional areas within a single thermoelectric leg. For example, the cross-sectional area of ​​both ends of a single thermoelectric leg that are disposed toward the electrode may be larger than the cross-sectional area between the ends. This may result in a larger temperature difference between the ends, thereby increasing thermoelectric efficiency.

[0063] The performance of a thermoelectric device according to an embodiment of the present invention can be expressed by a thermoelectric figure of merit (ZT). The thermoelectric figure of merit (ZT) can be expressed as in Equation 1.

[0064]

number

[0065] where α is the Seebeck coefficient [V / K], σ is the electrical conductivity [S / m], and α 2 σ is the power factor ([W / mK 2 ]), where T is the temperature and k is the thermal conductivity (W / mK). k can be expressed as a·cp·ρ, and a is the thermal diffusivity (cm 2 / S”, cp is the specific heat “J / gK”, and ρ is the density [g / cm 3 ].

[0066] To obtain the thermoelectric figure of merit of a thermoelectric element, the Z value (V / K) is measured using a Z meter, and the measured Z value can be used to calculate the thermoelectric figure of merit (ZT).

[0067] 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 electrode 150 disposed between the upper substrate 160 and the P-type thermoelectric leg 130 and the N-type thermoelectric leg 140 may include at least one of copper (Cu), silver (Ag), aluminum (Al), and nickel (Ni) and may have a thickness of 0.01 mm to 0.3 mm. If the thickness of the lower electrode 120 or the upper electrode 150 is less than 0.01 mm, the electrode function may be impaired and electrical conductivity may be reduced, and if it exceeds 0.3 mm, conduction efficiency may be reduced due to increased resistance.

[0068] Furthermore, the opposing lower substrate 110 and upper substrate 160 may be metal substrates, and their thickness may be 0.1 mm to 1.5 mm. If the thickness of the metal substrate is less than 0.1 mm or more than 1.5 mm, the heat dissipation characteristics or thermal conductivity may be excessively high, which may reduce the reliability of the thermoelectric device. Furthermore, if the lower substrate 110 and upper substrate 160 are metal substrates, an insulating layer 170 may be further formed between the lower substrate 110 and the lower electrode 120 and between the upper substrate 160 and the upper electrode 150, respectively. The insulating layer 170 may include a material having a thermal conductivity of 1 to 20 W / mK.

[0069] In this case, the lower substrate 110 and the upper substrate 160 may be formed to have different sizes. For example, the volume, thickness, or area of ​​one of the lower substrate 110 and the upper substrate 160 may be larger than the volume, thickness, or area of ​​the other. This may improve the heat absorption or heat dissipation performance of the thermoelectric module. For example, at least one of the volume, thickness, or area of ​​a substrate disposed in a high-temperature region for the Seebeck effect, a heat-generating region for the Peltier effect, or a substrate on which a sealing member for protecting the thermoelectric module from the external environment is disposed may be larger than the volume, thickness, or area of ​​the other substrate.

[0070] In addition, a heat dissipation pattern, for example, a concave-convex pattern, may be formed on the surface of at least one of the lower substrate 110 and the upper substrate 160. This can improve the heat dissipation performance of the thermoelectric device. If a concave-convex pattern is formed on the surface that contacts 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. The thermoelectric device 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.

[0071] 3 and 4, a sealing member 190 may be further disposed between the lower substrate 110 and the upper substrate 160. The sealing member 190 may be disposed on the sides of the lower electrode 120, the P-type thermoelectric leg 130, the N-type thermoelectric leg 140, and the upper electrode 150 between the lower substrate 110 and the upper substrate 160. This may seal the lower electrode 120, the P-type thermoelectric leg 130, the N-type thermoelectric leg 140, and the upper electrode 150 from external moisture, heat, contamination, etc. Here, the sealing member 190 may include a sealing case 192 disposed a predetermined distance from the outermost edges of the plurality of lower electrodes 120, the outermost edges of the plurality of P-type thermoelectric legs 130 and the plurality of N-type thermoelectric legs 140, and the outermost edges of the plurality of upper electrodes 150, a sealant 194 disposed between the sealing case 192 and the lower substrate 110, and a sealant 196 disposed between the sealing case 192 and the upper substrate 160. In this manner, the sealing case 192 may be in contact with the lower substrate 110 and the upper substrate 160 via the sealants 194 and 196. Therefore, if the sealing case 192 were in direct contact with the lower substrate 110 and the upper substrate 160, heat conduction would occur through the sealing case 192, thereby preventing a decrease in the temperature difference between the lower substrate 110 and the upper substrate 160. Here, the sealants 194, 196 may include at least one of epoxy resin and silicone resin, or may include tape coated on both sides with at least one of epoxy resin and silicone resin. The sealants 194, 194 serve to hermetically seal between the sealing case 192 and the lower substrate 110 and between the sealing case 192 and the upper substrate 160, and may enhance the sealing effect of the lower electrode 120, the P-type thermoelectric leg 130, the N-type thermoelectric leg 140, and the upper electrode 150. They may be mixed with finishing materials, finishing layers, waterproofing materials, waterproofing layers, etc. Here, the sealant 194 that seals between the sealing case 192 and the lower substrate 110 may be disposed on the upper surface of the lower substrate 110, and the sealant 196 that seals between the sealing case 192 and the upper substrate 160 may be disposed on the side of the upper substrate 160. Meanwhile, the sealing case 192 may have guide grooves G through which the lead wires 181, 182 connected to the electrodes can be drawn out.For this purpose, the sealing case 192 may be an injection-molded product made of plastic or the like, and may be used together with a sealing cover. However, the above description of the sealing member is merely an example, and the sealing member may be modified into various forms. Although not shown, a heat insulating material may be further included to surround the sealing member. Alternatively, the sealing member may include a heat insulating component.

[0072] Although the terms lower substrate 110, lower electrode 120, upper electrode 150, and upper substrate 160 have been used above, these are arbitrarily referred to as upper and lower for ease of understanding and convenience of explanation, and the positions may be reversed so that the lower substrate 110 and lower electrode 120 are disposed at the upper part and the upper electrode 150 and upper substrate 160 are disposed at the lower part.

[0073] Meanwhile, as mentioned above, attempts to use metal substrates to improve the thermal conductivity of thermoelectric elements are increasing. However, while a thermoelectric element including a metal substrate can provide advantageous effects in terms of thermal conductivity, it suffers from a problem of reduced voltage resistance. In particular, when a thermoelectric element is used in a high-voltage environment, a voltage resistance of 2.5 kV or more is required. To improve the voltage resistance of a thermoelectric element, multiple insulating layers with different compositions can be disposed between the metal substrate and the electrodes.

[0074] 5 is a cross-sectional view of a thermoelectric element according to an embodiment of the present invention, and redundant description of the same content as that described with reference to FIGS.

[0075] Referring to FIG. 5, a thermoelectric element 300 according to an embodiment of the present invention includes a first substrate 310, a first insulating layer 320 disposed on the first substrate 310, a second insulating layer 324 disposed on the first insulating layer 320, a plurality of first electrodes 330 disposed on the second insulating layer 324, a plurality of P-type thermoelectric legs 340 and a plurality of N-type thermoelectric legs 350 disposed on the plurality of first electrodes 330, a plurality of second electrodes 360 disposed on the plurality of P-type thermoelectric legs 340 and a plurality of N-type thermoelectric legs 350, a third insulating layer 370 disposed on the plurality of second electrodes 360, and a second substrate 380 disposed on the third insulating layer 370. The descriptions of the first substrate 110, first electrode 120, P-type thermoelectric leg 130, N-type thermoelectric leg 140, second electrode 150, and second substrate 160 in Figures 1 to 4 can be applied equally to the first substrate 310, first electrode 330, P-type thermoelectric leg 340, N-type thermoelectric leg 350, second electrode 360, and second substrate 380, respectively.

[0076] Although not shown in FIG. 5, a heat sink may be further disposed on the first substrate 310 or the second substrate 380, and a sealing member may be further disposed between the first substrate 310 and the second substrate 380.

[0077] According to this embodiment of the present invention, a first insulating layer 320 and a second insulating layer 324 are disposed on a first substrate 310 , and a first electrode 330 is disposed on the second insulating layer 324 .

[0078] The first insulating layer 320 may, for example, include a resin material, a composite containing silicon and aluminum, and an inorganic filler. The composite may be an organic-inorganic composite composed of an inorganic material containing Si and Al and an alkyl chain, or at least one of an oxide, carbide, and nitride containing silicon and aluminum. For example, the composite may include at least one of an Al-Si bond, an Al-O-Si bond, an Si-O bond, an Al-Si-O bond, and an Al-O bond. A composite containing at least one of an Al-Si bond, an Al-O-Si bond, an Si-O bond, an Al-Si-O bond, and an Al-O bond exhibits excellent insulating properties and thus provides high withstand voltage performance. Alternatively, the composite may be an oxide, carbide, or nitride containing titanium, zirconium, boron, zinc, or the like in addition to silicon and aluminum. To this end, the composite may be obtained by mixing aluminum with at least one of an inorganic binder and an organic-inorganic composite binder, followed by heat treatment. The inorganic binder may include, for example, at least one of silica (SiO2), metal alkoxide, boron oxide (BO3), and zinc oxide (ZnO2). The inorganic binder is an inorganic particle that can act as a binder by sol or gelling when exposed to water. At least one of silica (SiO2), metal alkoxide, and boron oxide (BO3) can enhance adhesion between the aluminum particles or between the aluminum particles and the first substrate 310, and zinc oxide (ZnO2) can enhance the strength and thermal conductivity of the first insulating layer 320. The inorganic filler may be dispersed within the composite and may include at least one of aluminum oxide and nitride. Here, the nitride may include at least one of boron nitride and aluminum nitride.

[0079] Meanwhile, the second insulating layer 324 may be a resin layer including at least one of an epoxy resin composition including an epoxy resin and an inorganic filler, and a silicone resin composition including PDMS (polydimethylsiloxane), thereby improving the insulating layer, bonding strength, and thermal conductivity between the first insulating layer 320 and the first electrode 330.

[0080] The inorganic filler may be contained in an amount of 60 to 80 wt% of the resin layer. If the inorganic filler is contained in an amount less than 60 wt%, the thermal conductivity effect will be reduced, and if the inorganic filler is contained in an amount more than 80 wt%, the inorganic filler will not be uniformly dispersed in the resin, and the resin layer may easily crack.

[0081] The epoxy resin may contain an epoxy compound and a curing agent. The epoxy compound may be contained in a volume ratio of 10 to 10:1. The epoxy compound may include at least one of a crystalline epoxy compound, an amorphous epoxy compound, and a silicon epoxy compound. The inorganic filler may include at least one of aluminum oxide or a nitride. The nitride may include at least one of boron nitride and aluminum nitride.

[0082] Meanwhile, the second insulating layer 324 may be formed by applying an uncured or semi-cured resin composition onto the first insulating layer 320, placing a pre-aligned plurality of first electrodes 330 thereon, applying pressure, and then performing a curing process. As a result, portions of the side surfaces of the plurality of first electrodes 330 are embedded in the second insulating layer 324. The height H1 of the side surfaces of the plurality of first electrodes 330 embedded in the second insulating layer 324 may be 0.1 to 1 times, preferably 0.2 to 0.9 times, and more preferably 0.3 to 0.8 times the thickness H of the plurality of first electrodes 330. When portions of the side surfaces of the plurality of first electrodes 330 are embedded in the second insulating layer 324, the contact area between the plurality of first electrodes 330 and the second insulating layer 324 is increased, thereby further improving the heat transfer performance and bonding strength between the plurality of first electrodes 330 and the second insulating layer 324. If the side height H1 of the plurality of first electrodes 330 embedded in the second insulating layer 324 is less than 0.1 times the thickness H of the plurality of first electrodes 330, it becomes difficult to obtain sufficient heat transfer performance and bonding strength between the plurality of first electrodes 330 and the second insulating layer 324. If the side height H1 of the plurality of first electrodes 330 embedded in the second insulating layer 324 exceeds 1 time the thickness H of the plurality of first electrodes 330, the second insulating layer 324 may rise above the plurality of first electrodes 330, which may result in an electrical short circuit.

[0083] Thus, the second insulating layer 324 may include a first recess R1 and a second recess R2 disposed around the first recess R1. The first electrodes 330 may be disposed in the first recess R1, respectively. A first vertical distance between the first recess R1 and the first substrate 310 may be smaller than a second vertical distance between the second recess R2 and the first substrate 310. More specifically, the thickness of the second insulating layer 324 between the first electrodes 330 may decrease from the side of each electrode toward the central region, forming a V-shape with a gentle peak. Therefore, the insulating layers 320, 324 between the first electrodes 330 have a thickness deviation, with a height T2 being the highest in the region directly contacting the side of each of the first electrodes 330 and a height T3 in the central region being lower than the height T2 in the region directly contacting the side of each of the first electrodes 330. That is, the height T3 of the central region of the insulating layers 320, 324 between the multiple first electrodes 330 is the lowest within the insulating layers 320, 324 between the multiple first electrodes 330. Furthermore, the height T1 of the insulating layers 320, 324 below the multiple first electrodes 330 is lower than the height T3 of the central region of the insulating layers 320, 324 between the multiple first electrodes 330. The second insulating layer 324 includes the second recesses R2, which can relieve stress applied to the insulating layer and thereby improve problems such as cracking and peeling of the insulating layer.

[0084] Meanwhile, the first insulating layer 320 and the second insulating layer 324 may have different compositions, which may change at least one of the hardness, elastic modulus, tensile strength, elongation, and Young's modulus of the first insulating layer 320 and the second insulating layer 324, thereby controlling the voltage resistance, thermal conductivity, bonding performance, and thermal shock mitigation performance. For example, the weight ratio of the composite and inorganic filler to the entire first insulating layer 320 may be higher than the weight ratio of the inorganic filler to the entire second insulating layer 324. As described above, the composite may be a composite containing silicon and aluminum, more specifically, a composite containing at least one of oxide, carbide, and nitride containing silicon and aluminum. For example, the weight ratio of the ceramics, i.e., the composite and inorganic filler, to the entire first insulating layer 320 may exceed 80 wt %, and the weight ratio of the ceramics, i.e., the inorganic filler, to the entire second insulating layer 324 may be 60 to 80 wt %. Thus, when the content of the composite and inorganic filler contained in the first insulating layer 320 is higher than the content of the inorganic filler contained in the second insulating layer 324, the hardness of the first insulating layer 320 is higher than the hardness of the second insulating layer 324. Therefore, the first insulating layer 320 can simultaneously have high withstand voltage performance and high thermal conductivity, and the second insulating layer 324 can have higher elasticity than the first insulating layer 320, thereby improving the adhesion between the first insulating layer 320 and the first electrode 330. Elasticity can be expressed as tensile strength. For example, the tensile strength of the second insulating layer 324 may be 2 to 5 MPa, preferably 2.5 to 4.5 MPa, and more preferably 3 to 4 MPa, and the tensile strength of the first insulating layer 320 may be 10 MPa to 100 MPa, preferably 15 MPa to 90 MPa, and more preferably 20 MPa to 80 MPa.

[0085] In this case, the thickness of second insulating layer 324 may be more than 1 time and not more than 3.5 times, preferably 1.05 times or more and not more than 2 times, and more preferably 1.1 times or more and not more than 1.5 times, the thickness of first insulating layer 320. For example, the thickness of first insulating layer 320 may be 35 μm or less, and the thickness of second insulating layer 324 may be more than 35 μm and not more than 80 μm, preferably more than 35 μm and not more than 70 μm, and more preferably more than 35 μm and not more than 50 μm.

[0086] When the thicknesses of the first insulating layer 320 and the second insulating layer 324 each satisfy these numerical ranges, it is possible to simultaneously obtain voltage resistance, thermal conductivity, bonding performance, and thermal shock mitigation performance. Furthermore, the recessed upper surface of the second recess R2 may be greater than the vertical height between the bottom surface of the electrode 330 and the upper surface of the substrate, but less than the vertical height between the upper surface of the electrode 330 and the upper surface of the substrate. This structure allows the electrode 330 to be stably filled and stress applied to the insulating layer to be efficiently mitigated.

[0087] Furthermore, the width of the first recess R1 can be set larger than the width of the second recess R2, which allows for a structure in which the electrodes are densely arranged on the substrate, thereby improving the power generation performance or temperature control performance of the thermoelectric element.

[0088] However, the first insulating layer 320 and the second insulating layer 324 may have different thermal expansion coefficients. Therefore, if the thermoelectric element 300 is exposed to high temperatures for a long period of time, the thermoelectric element 300 may warp due to stress, which may reduce the long-term reliability and durability of the thermoelectric element and, if the thermoelectric element is applied to a power generation device, may reduce the power generation performance of the power generation device.

[0089] According to the embodiment of the present invention, the warpage of the substrate is improved by using the arrangement structure of the second insulating layer 324 having a relatively larger thermal expansion coefficient than the first insulating layer 320.

[0090] FIG. 6 is a top view of a substrate, an insulating layer, and an electrode included in a thermoelectric element according to one embodiment of the present invention, FIG. 7(a) is an exploded perspective view of a thermoelectric element according to one embodiment of the present invention, and FIG. 7(b) is a perspective view of a thermoelectric element according to one embodiment of the present invention.

[0091] 6 and 7, a thermoelectric device 300 according to an embodiment of the present invention includes a first substrate 310, a first insulating layer 320 disposed on the first substrate 310, a second insulating layer 324 disposed on the first insulating layer 320, a plurality of first electrodes 330 disposed on the second insulating layer 324, a plurality of P-type thermoelectric legs 340 and a plurality of N-type thermoelectric legs 350 disposed on the plurality of first electrodes 330, a plurality of second electrodes 360 disposed on the plurality of P-type thermoelectric legs 340 and a plurality of N-type thermoelectric legs 350, a third insulating layer 370 disposed on the plurality of second electrodes 360, and a second substrate 380 disposed on the third insulating layer 370. A heat sink 390 may be further disposed on the second substrate 380.

[0092] Duplicate explanations of the same contents as those explained with reference to FIGS. 1 to 5 will be omitted.

[0093] When a voltage is applied to the thermoelectric device 300, the first substrate 310 absorbs heat due to the Peltier effect and acts as a low-temperature part, while the second substrate 380 releases heat and acts as a high-temperature part. Alternatively, when different temperatures are applied to the first substrate 310 and the second substrate 380, the temperature difference causes electrons in the high-temperature region to move to the low-temperature region, generating thermoelectric power. This is called the Seebeck effect, and the resulting thermoelectric power can generate electricity within the circuit of the thermoelectric device.

[0094] A plurality of first through-holes 311 may be formed in the first substrate 310. Similarly, a plurality of second through-holes (not shown) may be formed in the second substrate 380, and the plurality of first through-holes 311 may be disposed at positions corresponding to the plurality of second through-holes. As a result, a plurality of connecting members (not shown) may pass through the plurality of first through-holes 311 and the plurality of second through-holes, and the first substrate 310 and the second substrate 380 may be fixed by the plurality of connecting members (not shown).

[0095] Generally, the coefficient of thermal expansion (CTE) of copper substrate is about 18*10 -6 / mK, and the coefficient of thermal expansion (CTE) of the thermoelectric legs is approximately 17.5*10 -6 / mK, and the thermal expansion coefficients of the first insulating layer 320 and the second insulating layer 324 are greater than those of the copper substrate and the thermoelectric legs, and the thermal expansion coefficient of the second insulating layer 324 may be greater than that of the first insulating layer 320. For example, in order to satisfy both the bonding performance of the second insulating layer 324 and the voltage resistance performance of the first insulating layer 320, the thermal expansion coefficient of the second insulating layer 324 may be more than twice the thermal expansion coefficient of the first insulating layer 320.

[0096] According to an embodiment of the present invention, the second insulating layer 324 is disposed only on a portion of the first insulating layer 320 to minimize warpage of the substrate.

[0097] 6, the area of ​​the second insulating layer 324 may be smaller than the area of ​​the first insulating layer 320. That is, the second insulating layer 324 may be disposed on a portion of the first insulating layer 320, rather than the entire surface. This can improve warping of the first substrate 310 due to the difference in thermal expansion coefficients between the first insulating layer 320 and the second insulating layer 324, and can alleviate thermal stress. This can prevent short circuits or electrical open circuits in the first electrode 330 or the thermoelectric legs 340, 350, improve heat transfer efficiency, and ultimately improve the power generation or cooling characteristics of the thermoelectric element.

[0098] 6 and 7, the second insulating layer 324 may include a region P1 where the plurality of first electrodes 330, the plurality of semiconductor structures 340 and 350, and the plurality of second electrodes 360 are vertically overlapped. Hereinafter, the "vertical direction" may refer to the direction from the first substrate 310 to the second substrate 380 (Z direction).

[0099] The second insulating layer 324 may further include protruding patterns P2 and P3 protruding toward a first outer side S1 of the first substrate 310 in a region P1 where the plurality of first electrodes 330, the plurality of semiconductor structures 340 and 350, and the plurality of second electrodes 360 are vertically overlapped. Here, the first outer side S1 may be one of first to fourth outer sides S1 to S4 forming the edge of the first substrate 310, and may be disposed in a direction in which the plurality of terminal electrodes T1 and T2 protrude from the plurality of first electrodes 330. Accordingly, the distance between the overlapping region P1 of the first insulating layer 324 and the first outer side S1 of the first substrate 310 is greater than the distance between the overlapping region P1 of the first insulating layer 324 and the remaining outer sides (e.g., S2 to S4) of the first substrate 310. In this specification, the terminal electrodes T1 and T2 are electrodes for connecting electric wires and may be disposed on the same plane as the plurality of first electrodes 330 on the second insulating layer 324. The area of ​​each of the terminal electrodes T1, T2 may be larger than the area of ​​each of the plurality of first electrodes 330, so that connectors C1, C2 for connecting electric wires may be disposed on each of the terminal electrodes T1, T2. When the terminal electrodes T1, T2 protrude from the plurality of first electrodes 330 toward the first outer side S1, the distance from the first outer side S1 to the fourth outer side S4 of the first substrate 310, i.e., the distance in the Y direction, may be larger than the distance from the second outer side S2 to the third outer side S3 of the first substrate 310, i.e., the distance in the X direction.

[0100] In this case, the regions of the terminal electrodes T1, T2 where the connectors C1, C2 are arranged may not overlap in a vertical direction (e.g., Z direction in FIG. 7) with the semiconductor structures 340, 350, the second electrodes 360, the third insulating layer 370, the second substrate 380, and the heat sink 390. This makes it easy to connect lead wires to the connectors C1, C2.

[0101] In this way, when the regions of the terminal electrodes T1, T2 where the connectors C1, C2 are arranged do not overlap vertically with the second substrate 380 and the heat sink 390, the first outer side S1 may also not overlap vertically with the second substrate 380 and the heat sink 390. That is, as shown in Figures 6 and 7, at least a portion of the second outer side S2 and at least a portion of the third outer side S3 perpendicular to the first outer side S1 overlap vertically with the second substrate 380 and the heat sink 390, but the entire first outer side S1 may not overlap vertically with the second substrate 380 and the heat sink 390.

[0102] According to an embodiment of the present invention, the protruding patterns P2 and P3 include a first protruding pattern P2 and a second protruding pattern P3 spaced apart from each other, and the first terminal electrode T1 may be disposed on the first protruding pattern P2, and the second terminal electrode T2 may be disposed on the second protruding pattern P3. This eliminates the need to dispose the second insulating layer 324 on a portion of the first substrate 310, thereby minimizing the problem of warping of the first substrate 310 due to the second insulating layer 324 having a large thermal expansion coefficient.

[0103] More specifically, according to an embodiment of the present invention, the width (W1+W2) of the protruding patterns P2 and P3 may be smaller than the width W of the region P1 where the plurality of first electrodes 330, the plurality of semiconductor structures 340 and 350, and the plurality of second electrodes 360 vertically overlap, and the protruding patterns P2 and P3 may be spaced apart from the first outer side S1 of the first substrate 310. In this specification, the width may be defined as the distance in the X direction, and the length may be defined as the distance in the Y direction. Accordingly, since the second insulating layer 324 is not disposed in a portion between the region P1 where the plurality of first electrodes 330, the plurality of semiconductor structures 340 and 350, and the plurality of second electrodes 360 vertically overlap and the first outer side S1 of the first substrate 310, warping of the first substrate 310 in the Y direction may be reduced.

[0104] In this case, the separation distance d1 between the first protruding pattern P2 and the second protruding pattern P3 may be 0.9 to 2 times, preferably 0.95 to 1.5 times, and more preferably 0.97 to 1.2 times the distance d2 between the second outer side S2 of the first substrate 310 and the first protruding pattern P2 and the distance d3 between the third outer side S3 of the first substrate 310 and the second protruding pattern P3. As a result, the region where the second insulating layer 324 is not disposed between the second outer side S2 and the third outer side S3 of the first substrate 310 and the region where the second insulating layer 324 is not disposed between the first protruding pattern P2 and the second protruding pattern P3 act as a buffer against thermal expansion of the protruding patterns P2 and P3 of the second insulating layer 324, thereby reducing warpage of the first substrate 310 in the X direction, and the warpage of the first substrate 310 in the X direction may be symmetrical about the center of the first substrate 310 in the X direction.

[0105] Meanwhile, as described above, the protruding patterns P2 and P3 and the first outer side S1 of the first substrate 310 may be spaced apart from each other. Accordingly, the region where the second insulating layer 324 is not disposed between the protruding patterns P2 and P3 and the first outer side S1 of the first substrate 310 buffers the thermal expansion of the protruding patterns P2 and P3 of the second insulating layer 324, thereby reducing warpage of the first substrate 310 in the Y-axis direction.

[0106] In this case, a sealing member (not shown) may be disposed to contact the first insulating layer 320 at the first outer side S1 and to contact the second insulating layer 324 at the fourth outer side S4. That is, because the second insulating layer 324 is not disposed on the first outer side S1 of the first substrate 310, warping of the first substrate 310 in the Y-axis direction can be reduced even if the length of the first substrate 310 in the Y-axis direction is increased by the terminal electrodes T1 and T2. In this case, the protrusion length D1 of the protruding patterns P2 and P3 may be greater than the length D2 from the protruding patterns P2 and P3 to the first outer side S1 of the first substrate 310. As a result, the length of the first substrate 310 in the Y-axis direction is not longer than necessary, thereby reducing warping of the first substrate 310 in the Y-axis direction.

[0107] Meanwhile, according to an embodiment of the present invention, the first insulating layer 320 may be disposed to be spaced apart from the edges of the first substrate 310, i.e., at least a portion of the first to fourth outer sides S1 to S4 of the first substrate 310. When the first insulating layer 320 is disposed to be spaced apart from at least a portion of the edges of the first substrate 310, the edges of the first substrate 310 can act as a buffer against thermal expansion of the first insulating layer 320, thereby reducing warping of the first substrate 310. Also, for example, the thermal expansion coefficient of the first insulating layer 320 may be different from or greater than the thermal expansion coefficient of the first substrate 310.

[0108] Similarly, the second insulating layer 324 may be disposed so as to be spaced apart from at least a portion of the edge of the first insulating layer 320. When the second insulating layer 324 is disposed so as to be spaced apart from at least a portion of the edge of the first insulating layer 320, the edge of the first insulating layer 320 can act as a buffer against thermal expansion of the second insulating layer 324, thereby reducing warping of the first substrate 310. Also, for example, the thermal expansion coefficient of the second insulating layer 324 may be greater than the thermal expansion coefficient of the first insulating layer 320.

[0109] 7, the second substrate 380 is disposed on the plurality of second electrodes 360, and at this time, the second substrate 380 does not need to be vertically overlapped with the protruding patterns P2 and P3 of the second insulating layer 324. Terminal electrodes T1 and T2 are disposed on the protruding patterns P2 and P3 of the second insulating layer 324, and connectors C1 and C2 for connecting electrical wires are disposed on the terminal electrodes T1 and T2. Therefore, when the second substrate 380 is not vertically overlapped with the protruding patterns P2 and P3 of the second insulating layer 324, electrical wire connection through the connectors is easy.

[0110] 6, the second recess R2 of the second insulating layer 324 may be disposed around the first electrode 330. The first electrode 330 may have a shape with different lengths in the X-axis direction and the Y-axis direction. Accordingly, the second recess R2 of the second insulating layer 324 may also have a plurality of shapes with different lengths in the X-axis direction or the Y-axis direction. In a region where the plurality of first electrodes 330 and the plurality of second electrodes 360 are vertically overlapped, the second recess R2 of the second insulating layer 324 may be located between the electrodes, and the protruding patterns P2 and P3 of the second insulating layer 324 may have flat portions rather than recesses. Therefore, stress applied to the second insulating layer 324 from the first substrate 310 may be alleviated in the X-axis direction and the Y-axis direction, thereby preventing warping of the substrate and cracking or peeling of the first insulating layer 320 and the second insulating layer 324. However, without being limited thereto, because the distance between the terminal electrode T1 and the electrode 330 is greater than the distance between each of the plurality of first electrodes 330, the second recesses R2 of the second insulating layer 324 may appear as flat portions in the protruding patterns P2, P3 of the second insulating layer 324, or recesses having a width in the X-axis direction and a length in the Y-axis direction greater than the second recesses R2 of the second insulating layer 324 disposed between the plurality of first electrodes 330 may be disposed. The second recesses R2 of the second insulating layer 324 may have different widths in the region P1 where the plurality of first electrodes 330 and the plurality of second electrodes 360 are vertically overlapped, and the widths of the protruding patterns P2, P3 may also have different widths, which may have the effect of suppressing warpage of the substrate and effectively prevent cracks and peeling of the second insulating layer 324.

[0111] Although the above-described embodiment discloses a configuration in which the first insulating layer 320 and the second insulating layer 324 are separately disposed, this is not limiting, and the first insulating layer 320 and the second insulating layer 324 may be disposed as a single layer. Even when disposed as a single layer, a resin material containing an inorganic charging material may be used to ensure the above-described thermal conductivity and voltage resistance characteristics, but this is not limiting. Furthermore, even when disposed as a single layer, the pattern of the second insulating layer 324 may have the same shape.

[0112] Meanwhile, according to an embodiment of the present invention, at least one of the first substrate 310 and the second substrate 380 may be formed of a plurality of divided substrates in order to reduce warpage of the substrate.

[0113] FIG. 8 is a top view of a substrate, insulating layer and electrodes included in a thermoelectric element according to another embodiment of the present invention, FIG. 9 is a perspective view of a thermoelectric element according to another embodiment of the present invention, FIG. 10 is a perspective view of a thermoelectric element according to yet another embodiment of the present invention, and FIG. 11 is a top view of a substrate, insulating layer and electrodes included in a thermoelectric element according to yet another embodiment of the present invention.

[0114] 8 to 11, a thermoelectric device 300 according to an embodiment of the present invention includes a first substrate 310, a first insulating layer 320 disposed on the first substrate 310, a second insulating layer 324 disposed on the first insulating layer 320, a plurality of first electrodes 330 disposed on the second insulating layer 324, a plurality of P-type thermoelectric legs 340 and a plurality of N-type thermoelectric legs 350 disposed on the plurality of first electrodes 330, a plurality of second electrodes 360 disposed on the plurality of P-type thermoelectric legs 340 and a plurality of N-type thermoelectric legs 350, a third insulating layer 370 disposed on the plurality of second electrodes 360, and a second substrate 380 disposed on the third insulating layer 370. A heat sink 390 may be further disposed on the second substrate 380.

[0115] Duplicate explanations of the same contents as those explained with reference to FIGS. 1 to 7 will be omitted.

[0116] According to an embodiment of the present invention, the second substrate 380 may include a plurality of second substrates 381, 382, ​​383, and 384 spaced apart from one another, and each of the second substrates 381, 382, ​​383, and 384 included in the first substrate 310 and the second substrate 380 may have a through hole formed therein for a connecting member (not shown) to pass through.

[0117] A plurality of first through holes 311 may be formed in the first substrate 310. A second through hole may be formed in each of the plurality of second substrates 381, 382, ​​383, and 384, and the plurality of first through holes 311 may be disposed at positions corresponding to the second through holes. As a result, a plurality of connecting members (not shown) may pass through the plurality of first through holes 311 and the second through holes, and the first substrate 310 and the plurality of second substrates 381, 382, ​​383, and 384 may be fixed by the plurality of connecting members (not shown).

[0118] Meanwhile, when heat sinks 391, 392, 393, and 394 are disposed on second substrates 381, 382, ​​383, and 384, a third through hole may be formed in each heat sink 391, 392, 393, and 394, and the first through holes 311 may be disposed at positions corresponding to the second and third through holes. Thus, a plurality of connecting members (not shown) may pass through the first, second, and third through holes 311, and the first substrate 310, second substrate 380, and heat sink 390 may be fixed by the connecting members.

[0119] On the other hand, as shown in Figures 8 to 10, when the second substrate 380 is divided into multiple second substrates 381, 382, ​​383, and 384, the problem of thermal deformation of the second substrate 380 due to thermal expansion can be prevented even if the second substrate 380 is frequently exposed to high temperatures, and it is easy to apply to large area applications.

[0120] 10, an insulator 1000 may be further disposed in the spaced apart areas between the plurality of second substrates 381, 382, ​​383, and 384. In this manner, the insulator 1000 may bond the plurality of second substrates 381, 382, ​​383, and 384 together, thereby sealing the spaced apart areas between the plurality of second substrates 381, 382, ​​383, and 384.

[0121] On the other hand, if the second substrate 380 includes a plurality of second substrates 381, 382, ​​383, and 384 arranged at a distance from each other, the plurality of first electrodes 330 arranged on the first substrate 310 may be arranged to correspond to the plurality of second substrates 381, 382, ​​383, and 384.

[0122] That is, as shown in FIG. 8, the plurality of first electrodes 330 includes a plurality of electrode groups spaced apart from each other, the second electrode 360 ​​includes a plurality of electrode groups spaced apart from each other, and each electrode group of the first electrodes 330 may overlap with each electrode group of the second electrode 360 ​​in a direction from the first substrate 310 to the second substrate 380.

[0123] 8, the first electrode 330 may include a plurality of electrode groups 331, 332, 333, and 334 spaced apart from one another, and each of the electrode groups 331, 332, 333, and 334 may include a plurality of electrodes 330E spaced apart from one another. Although not shown in FIG. 8, the second electrode 360 ​​may include a plurality of electrode groups overlapping the plurality of electrode groups 331, 332, 333, and 334 in a direction perpendicular to the first substrate 310.

[0124] The first terminal electrode T1 and the second terminal electrode T2 may protrude from one of the plurality of electrode groups 331, 332, 333, and 334. A connector (not shown) may be disposed on each of the first terminal electrode T1 and the second terminal electrode T2, and the first electrode 330 may be connected to an external power source through the connector. Meanwhile, the first electrode 330 may further include a connecting electrode portion 330C that connects at least some of the plurality of electrode groups 331, 332, 333, and 334. The connecting electrode unit 330C may include, for example, at least one of a first connecting electrode 330C1 disposed between the 1-1 electrode group 331 and the 2-1 electrode group 332, a second connecting electrode 330C2 disposed between the 1-1 electrode group 331 and the 1-2 electrode group 333, a third connecting electrode 330C3 disposed between the 1-2 electrode group 333 and the 2-2 electrode group 334, and a fourth connecting electrode connecting the 2-1 electrode group 332 and the 2-2 electrode group 334. The electrode groups 331, 332, 333, and 334 may be directly or indirectly connected to other electrode groups through the connecting electrode unit 330C, and may form an electrical path through the first terminal electrode T1 and the second terminal electrode T2.

[0125] Each electrode group 331, 332, 333, and 334 may be arranged with a hole arrangement region 310H left empty. Although not shown, the second electrode 360 ​​may also be arranged with a hole arrangement region corresponding to the hole arrangement region 310H left empty. Here, the hole arrangement region 310H may refer to an area formed by an imaginary line connecting the edge of the electrode 330E closest to the hole 311. The area of ​​the hole arrangement region may be four times or more, preferably six times or more, and more preferably eight times or more, the area of ​​the electrode 330E. This allows a predetermined distance to be maintained between the hole 311 and the first electrode 330, and therefore a predetermined distance to be maintained between a fastener (not shown) passing through the hole 311 and the first electrode 330. As a result, the withstand voltage of the thermoelectric device 300 may be maintained at AC 1 kV or more.

[0126] In this case, the spacing between the multiple electrode groups 331, 332, 333, 334 may correspond to the spacing between the multiple second substrates 381, 382, ​​383, 384, and the spacing between the multiple electrode groups 331, 332, 333, 334 may be greater than the spacing between the multiple electrodes 330E within each electrode group 331, 332, 333, 334.

[0127] For example, if the first electrode 330 includes a 1-1 electrode group 331, a 2-1 electrode group 332 arranged so as to be spaced apart from the 1-1 electrode group 331 in a first direction, a 1-2 electrode group 333 arranged so as to be spaced apart from the 1-1 electrode group 331 in a second direction perpendicular to the first direction, and a 2-2 electrode group 334 spaced apart from the 1-2 electrode group 333 in the first direction and spaced apart from the 2-1 electrode group 332 in the second direction, the 1-1 electrode group 331 and the 1-2 electrode group 333 may be spaced apart from the 2-1 electrode group 332 and the 2-2 electrode group 334 in the first direction, and the 1-1 electrode group 331 and the 2-1 electrode group 332 may be spaced apart from the 1-2 electrode group 333 and the 2-2 electrode group 334 in the second direction.

[0128] 11, dummy portions 900 may be disposed on the sides of the electrode groups 331, 332, 333, and 334 in at least a portion of the separation regions between the electrode groups 331, 332, 333, and 334. When the dummy portions 900 are disposed in this manner, stress is applied uniformly to the entire first substrate 310, thereby reducing the W-shaped warpage phenomenon.

[0129] For example, the first dummy section 910 may be disposed between the 1-1 electrode group 331 and the 2-1 electrode group 332. The second dummy section 920 may be disposed between the 1-2 electrode group 333 and the 2-2 electrode group 334. The third dummy section 930 may be disposed between the 1-1 electrode group 331 and the 2-1 electrode group 332 and the 1-2 electrode group 333 and the 2-2 electrode group 334. In this case, the first dummy section 910 and the second dummy section 920 may be spaced apart from each other by the third dummy section 930. Alternatively, a first linking electrode 330C1 may be arranged between the first electrode group 331 and the second electrode group 332 between the first dummy section 910 and the third dummy section 930, and a third linking electrode 330C3 may be arranged between the first-second electrode group 333 and the second-second electrode group 334 between the second dummy section 920 and the third dummy section 930.

[0130] According to this, when the first substrate 310 is exposed to high temperatures, stress is applied uniformly to the entire first substrate 310, so that the W-shaped warpage of the first substrate 310 can be minimized.

[0131] In this case, at least one of the first dummy portion 910, the second dummy portion 920, and the third dummy portion 930 may include a plurality of dummy structures having the same shape and size as each electrode 330E included in each electrode group and spaced apart from each other.

[0132] Accordingly, when the first substrate 310 is exposed to high temperatures, stress is applied uniformly to the entire first substrate 310, thereby minimizing the W-shaped warpage of the first substrate 310 and facilitating the design and arrangement of the dummy portion 900 in the manufacturing process.

[0133] In this case, each dummy structure may be a metal layer. For example, the metal layer may have the same material, shape, and size as the electrode 330E, but no thermoelectric legs may be disposed on the metal layer, and the metal layer may not be electrically connected to other electrodes 330E. This simplifies the design and arrangement of the dummy portion 900 during the manufacturing process.

[0134] Alternatively, each dummy structure may be a resin layer. For example, the resin layer may contain at least one of epoxy resin and polyimide resin. Such a resin layer has heat resistance, thereby preventing heat conduction between each electrode group and increasing the efficiency of heat conduction between the electrodes in each electrode group and the first substrate. Furthermore, such a resin layer has insulating properties, thereby increasing the withstand voltage performance of the first substrate 310.

[0135] Here, the area of ​​the second insulating layer 324 may be smaller than the area of ​​the first insulating layer 320. That is, the second insulating layer 324 may include a region P1 where the plurality of first electrodes 330, the plurality of semiconductor structures 340, 350, and the plurality of second electrodes 360 are vertically overlapped, and protruding patterns P2, P3 protruding from the region P1 toward a first outer side S1 of the first substrate 310. Terminal electrodes T1, T2 may be disposed on the protruding patterns P2, P3, and the protruding patterns P2, P3 may be disposed so as not to vertically overlap with the second substrates 381, 382, ​​383, 384.

[0136] Other than this, the details relating to the first substrate 310, the first insulating layer 320, and the second insulating layer 324 are the same as those described in Figures 5 to 7, so for the sake of convenience, duplicated descriptions will be omitted.

[0137] This can prevent warping of the substrates not only on the first substrate 310 side but also on the second substrate 380 side, thereby minimizing warping of the entire thermoelectric device 300.

[0138] FIG. 12 shows a bonding structure between a heat sink and a second substrate in a thermoelectric device according to an embodiment of the present invention.

[0139] 12 , the thermoelectric device 300 may be fastened by a plurality of coupling members 400. For example, if a heat sink 390 is disposed on the second substrate 380, the plurality of coupling members 400 may fasten the heat sink 390 to the second substrate 380, or fasten the heat sink 390, the second substrate 380, and a first substrate (not shown), or fasten the heat sink 390, the second substrate 380, and the first substrate (not shown) and a cooling unit (not shown), or fasten the second substrate 380, the first substrate (not shown) and a cooling unit (not shown), or fasten the second substrate 380 and the first substrate (not shown). Alternatively, the first substrate (not shown) and the cooling unit (not shown) may be connected by another fastening member outside the effective area on the first substrate (not shown).

[0140] To this end, a through hole S through which the coupling member 400 passes may be formed in the heat sink 390, the second substrate 380, the first substrate (not shown), and the cooling unit (not shown). A separate insulating insert member 410 may be further disposed between the through hole S and the coupling member 400. The separate insulating insert member 410 may be an insulating insert member that surrounds the outer periphery of the coupling member 400 or an insulating insert member that surrounds the wall surface of the through hole S. This may increase the insulation distance of the thermoelectric element.

[0141] On the other hand, the shape of the insulating insert member 410 is as shown in FIG. 12(a) and FIG. 12(b).

[0142] 12(a), the diameter d2' of the through hole S on the first surface of the second substrate 280 that contacts the second electrode may be the same as the diameter of the through hole S on the first surface of the first substrate that contacts the first electrode. In this case, the diameter d2' of the through hole S formed on the first surface of the second substrate 380 may be different from the diameter d2 of the through hole S formed on the second surface opposite the first surface, depending on the shape of the insulating insert member 410. Although not shown, if the insulating insert member 410 is disposed only on a portion of the upper surface of the second substrate 380 without forming a step in the through hole S area, or if the insulating insert member 410 is disposed so as to extend from the upper surface of the second substrate 380 to a portion or all of the wall surface of the through hole S, the diameter d2' of the through hole S formed on the first surface of the second substrate 380 may be the same as the diameter d2 of the through hole S formed on the second surface opposite the first surface.

[0143] 12(b), depending on the shape of the insulating insert member 410, the diameter d2' of the through-hole S on the first surface that contacts the second electrode of the second substrate 380 may be larger than the diameter of the through-hole S on the first surface that contacts the first electrode of the first substrate. In this case, the diameter d2' of the through-hole S on the first surface of the second substrate 380 may be 1.1 to 2.0 times the diameter of the through-hole S on the first surface of the first substrate. If the diameter d2' of the through-hole S on the first surface of the second substrate 380 is less than 1.1 times the diameter of the through-hole S on the first surface of the first substrate, the insulating effect of the insulating insert member 410 may be insufficient, resulting in dielectric breakdown of the thermoelectric element. If the diameter d2' of the through-hole S on the first surface of the second substrate 380 is more than 2.0 times the diameter of the through-hole S on the first surface of the first substrate, the size of the area occupied by the through-hole S increases relatively, reducing the effective area of ​​the second substrate 380 and reducing the efficiency of the thermoelectric element.

[0144] Furthermore, the diameter d2' of the through hole S formed on the first surface of the second substrate 380 may be different from the diameter d2 of the through hole S formed on the second surface opposite the first surface, depending on the shape of the insulating insert member 410. As described above, if no step is formed in the through hole S region of the second substrate 380, the diameter d2' of the through hole S formed on the first surface of the second substrate 380 may be the same as the diameter d2 of the through hole S formed on the second surface opposite the first surface.

[0145] The results of a simulation of the warpage improvement effect of a thermoelectric element according to an embodiment of the present invention will be described below.

[0146] Figure 13 shows the simulation results when the upper substrate of the thermoelectric element is a single substrate, and Figure 14 shows the simulation results when the upper substrate of the thermoelectric element is a divided substrate. In the simulation, the thermal expansion coefficient of the substrate is 18*10 -6 / mK, and the thermal expansion coefficient of the thermoelectric legs is 17.5*10 -6 / mK, and the thermal expansion coefficient of the first insulating layer is 30*10 -6 / mK or less, and the thermal expansion coefficient of the second insulating layer is 92*10 -6 The upper substrate in the model of Figure 13(a) was a single substrate as shown in Figure 7, while the upper substrate in the model of Figure 14(a) was composed of divided substrates as shown in Figure 9. The temperature of the lower substrate was fixed at 35°C, and the temperature of the upper substrate was reduced from 200°C to 50°C and then increased back to 200°C, which constituted one cycle. The warpage of the substrate was measured after a total of 30 cycles. Figures 13(b) and 14(b) are cross sections taken in a direction perpendicular to the protrusion direction of the terminal electrodes in Figures 13(a) and 14(a), respectively (hereinafter referred to as the minor axis direction) after 30 cycles. Figures 13(c) and 14(c) are graphs showing the degree of deformation between points 1 and 2 in Figures 13(b) and 14(b), respectively, as a function of the number of cycles. (c) of FIG. 13 and (c) of FIG. 14 are graphs with the same scale.

[0147] 13(a) to 13(c) and 14(a) to 14(c), it can be seen that when the upper substrate is configured as a divided substrate, the warpage in the minor axis direction of the substrate can be significantly reduced. That is, when the upper substrate is a single substrate, the ratio of the gap between points 1 and 2 (FIG. 13(a)) to the gap between points 1 and 2 (FIG. 14(a)) when the upper substrate is a divided substrate is reduced to about 54%.

[0148] Figure 15 shows the simulation results for a model in which the second insulating layer is applied over the entire surface, and Figure 16 shows the simulation results for a model in which the second insulating layer is applied in a pattern. In the simulation, the thermal expansion coefficient of the substrate is 18*10 -6 / mK, and the thermal expansion coefficient of the thermoelectric legs is 17.5*10 -6 / mK, and the thermal expansion coefficient of the first insulating layer is 30*10 -6 / mK or less, and the thermal expansion coefficient of the second insulating layer is 92*10 -6 The dielectric constant was set to / mK, and the upper substrate was configured as a divided substrate as shown in Figure 9. In the model of Figure 15, the second insulating layer was applied over the entire surface of the first insulating layer, and in the model of Figure 16, the second insulating layer was applied over a portion of the first insulating layer to have a protruding pattern, as shown in Figures 6 and 8.

[0149] The temperature of the lower substrate was fixed at 35°C, and the temperature of the upper substrate was reduced from 200°C to 50°C and then increased back to 200°C. This process constitutes one cycle, and the warpage of the substrate was measured after a total of 30 cycles. Figures 15(b) and 16(b) are graphs showing the deformation between points 1 and 2 in the protruding direction of the terminal electrodes (hereinafter referred to as the long axis direction) in Figures 15(a) and 15(a), respectively, after 30 cycles. Figures 15(b) and 16(b) are graphs with the same scale.

[0150] 15 and 16, it can be seen that the gap between points 1 and 2, i.e., the warpage in the longitudinal direction, is significantly lower in the model of Fig. 16 compared to the model of Fig. 15. That is, the ratio of the gap between points 1 and 2 in the model where the second insulating layer is pattern-coated (Fig. 16(b)) to the gap between points 1 and 2 in the model where the second insulating layer is coated over the entire surface (Fig. 15(b)) can be reduced to about 53%.

[0151] As described above, it can be seen that the warpage of the substrate can be improved by patterning the second insulating layer, as in the embodiment of the present invention. Furthermore, it can be seen that the warpage of the substrate can be improved by forming one of the first and second substrates as a divided substrate. When the warpage shape and warpage width of the substrate are improved, the reaction force generated at the interface between the electrode and thermoelectric leg in the thermoelectric element can be reduced, and the bonding strength between the thermoelectric element and the cooling unit can be increased, resulting in a thermoelectric element with excellent long-term reliability, durability, and power generation performance.

[0152] Although not shown, when a thermoelectric element according to an embodiment of the present invention is applied to a power generation device using the Seebeck effect, the thermoelectric element may be coupled to a first fluid-flow unit and a second fluid-flow unit. The first fluid-flow unit may be disposed on one of the first and second substrates of the thermoelectric element, and the second fluid-flow unit may be disposed on the other of the first and second substrates of the thermoelectric element. At least one of the first and second fluid-flow units may have a flow path through which at least one of the first and second fluids flows. In some cases, at least one of the first and second fluid-flow units may be omitted, and at least one of the first and second fluids may flow directly through the substrate of the thermoelectric element. For example, the first fluid may flow adjacent to one of the first and second substrates, and the second fluid may flow adjacent to the other. In this case, the temperature of the second fluid may be higher than the temperature of the first fluid. As such, the first fluid-flow unit may be referred to as a cooling unit. In another embodiment, the temperature of the first fluid may be higher than the temperature of the second fluid. Therefore, the second fluid-flow section may be referred to as a cooling section. The heat sink 390 may be connected to the substrate of the first or second fluid-flow section through which the higher-temperature fluid flows. The absolute value of the temperature difference between the first and second fluids may be 40°C or more, preferably 70°C or more, and more preferably 95°C to 185°C.

[0153] When a thermoelectric element or thermoelectric module according to embodiments of the present invention is used in a vehicle such as a ship or an automobile, it can generate electricity using waste heat discharged from the engine's exhaust side. The generated energy can be stored in a battery of the vehicle and supplied to various devices in the vehicle, such as lighting and a gas circulation system. When a thermoelectric element according to embodiments of the present invention is disposed on the intake side of the engine, the thermoelectric element according to embodiments of the present invention can be used not only as a power generation device but also as a temperature control device. When a thermoelectric element according to embodiments of the present invention is used in a temperature control device, the temperature of gas injected into the engine can be reduced, thereby increasing the amount of gas injected into the engine, thereby improving the engine's fuel efficiency. As a result, the engine in the vehicle and the thermoelectric element according to embodiments of the present invention can influence each other and have functional integration or technical interrelationship. Furthermore, in the shipping and transportation industries using vehicles incorporating thermoelectric elements according to embodiments of the present invention, the thermoelectric element according to embodiments of the present invention can reduce shipping costs and create an environmentally friendly industrial environment, and can have functional integration or technical interrelationship with the thermoelectric element according to embodiments of the present invention.

[0154] When a thermoelectric element according to an embodiment of the present invention is used in a power plant, the heat generated in the power plant can be used to adjust the efficiency of fuel used versus energy production, thereby adjusting energy production costs and creating an environmentally friendly industrial environment, and the thermoelectric element according to an embodiment of the present invention and the power plant can form a functional integration or technical linkage.

[0155] When the thermoelectric element according to an embodiment of the present invention is used in a plant such as a steel mill, it can reduce energy consumption in the plant by generating energy through power generation using waste heat generated in the plant, and when it is used in a temperature control device, it can affect the manufacturing costs of the product or the temperature control within the plant, thereby affecting other components of the plant, so the thermoelectric element according to an embodiment of the present invention and other components of the plant can form a functional integration or technical linkage.

[0156] The thermoelectric device according to an embodiment of the present invention can be used in a wireless network temperature sensor or a power supply device for supplying energy to the sensor. That is, since it is possible to permanently supply energy to the sensor, etc., when used in a temperature sensor installed underground or a power supply device for the temperature sensor, it can be functionally integrated or technically linked with the wireless network system.

[0157] The thermoelectric device according to an embodiment of the present invention can be used in a temperature control device, and when used in an electric vehicle, a battery charging device, etc., it can achieve functional integration or technical interlocking through functions such as adjusting the temperature of the electric vehicle or the battery charging device and increasing the stability of the electric vehicle or the battery charging device.

[0158] Although the present invention has been described above with reference to preferred embodiments, it should be understood that those skilled in the art can make various modifications and changes to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below.

Claims

1. substrate, a first insulating layer disposed on the substrate; a second insulating layer disposed on the first insulating layer and having an area smaller than an area of ​​the first insulating layer; a plurality of first electrodes disposed on the second insulating layer; a plurality of semiconductor structures disposed on each of the plurality of first electrodes; and a plurality of second electrodes disposed on the plurality of semiconductor structures; the second insulating layer includes an overlapping region where the first electrodes, the second electrodes, and the semiconductor structures are vertically overlapped, and a protruding pattern protruding from the overlapping region toward a first outer side, which is one of a plurality of outer sides forming an edge of the substrate; the first insulating layer is disposed so as to be spaced apart from at least a portion of an edge of the substrate; the second insulating layer is disposed so as to be spaced apart from at least a portion of an edge of the first insulating layer; the thermal expansion coefficient of the first insulating layer is greater than the thermal expansion coefficient of the substrate; The thermoelectric element, wherein the second insulating layer has a thermal expansion coefficient greater than the thermal expansion coefficient of the first insulating layer.

2. The thermoelectric element according to claim 1 , wherein the width of the protruding pattern is smaller than the width of the overlapping region.

3. The thermoelectric device according to claim 2 , wherein the protrusion pattern and the first outer side of the substrate are spaced apart from each other.

4. The thermoelectric element according to claim 3 , wherein a protruding length of the protruding pattern is greater than a length from the protruding pattern to the first outer side.

5. The thermoelectric element according to claim 2 , wherein the protrusion patterns include a first protrusion pattern and a second protrusion pattern spaced apart from each other.

6. 6. The thermoelectric element of claim 5, wherein a separation distance between the first protruding pattern and the second protruding pattern is 0.9 to 2 times a distance between a second outer side of the substrate perpendicular to the first outer side and the first protruding pattern, and a distance between a third outer side of the substrate perpendicular to the first outer side and facing the second outer side and the second protruding pattern.

7. The semiconductor device further includes a first terminal electrode and a second terminal electrode protruding from the plurality of first electrodes toward the first outer side, The thermoelectric element according to claim 5 , wherein the first terminal electrode and the second terminal electrode are disposed on the first protruding pattern and the second protruding pattern, respectively.

8. The thermoelectric element according to claim 7 , wherein the area of ​​each of the first terminal electrode and the second terminal electrode is larger than the area of ​​each of the plurality of first electrodes.

9. The thermoelectric element of claim 1 , further comprising a sealing member arranged to contact the first insulating layer at the first outer side and to contact the second insulating layer at a fourth outer side opposite the first outer side.

10. the second insulating layer includes a first recess and a second recess disposed around the first recess; 2. The thermoelectric element of claim 1, wherein the plurality of first electrodes are respectively disposed on the first recesses, and a first vertical distance between the first recesses and the substrate is smaller than a second vertical distance between the second recesses and the substrate.

11. The thermoelectric element of claim 1 , wherein the first insulating layer and the second insulating layer have different compositions.

12. further comprising an upper substrate disposed on the plurality of second electrodes; The thermoelectric device according to claim 1 , wherein the upper substrate does not overlap the protrusion pattern vertically.

13. 13. The thermoelectric element of claim 12, wherein the plurality of first electrodes includes a first electrode group and a second electrode group arranged to be spaced apart from each other, the plurality of second electrodes includes a third electrode group and a fourth electrode group arranged to be spaced apart from each other, the first electrode group and the third electrode group overlap each other in a direction perpendicular to the substrate, and the second electrode group and the fourth electrode group overlap each other in a direction perpendicular to the substrate.

14. The thermoelectric device of claim 13 , wherein the upper substrate comprises a first upper substrate disposed on the third electrode group, and a second upper substrate spaced apart from the first upper substrate and disposed on the fourth electrode group.

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