thermoelectric device

Abstract

A thermoelectric device according to one embodiment of the present application includes a first insulating layer, a first substrate disposed on the first insulating layer, a second insulating layer disposed on the first substrate, a first electrode disposed on the second insulating layer, a P-type thermoelectric leg and an N-type thermoelectric leg disposed on the first electrode, a second electrode disposed on the P-type thermoelectric leg and the N-type thermoelectric leg, a third insulating layer disposed on the second electrode, and a second substrate disposed on the third insulating layer, wherein the first insulating layer includes a first aluminum oxide layer, the first substrate is an aluminum substrate, the second substrate is a copper substrate, the first substrate is a low temperature portion, and the second substrate is a high temperature portion.

Description

Technical Field

[0001] The present invention relates to a thermoelectric device, and more specifically, to a substrate and insulating layer of a thermoelectric device. Background Technology

[0002] The thermoelectric effect is a phenomenon caused by the movement of electrons and holes inside a material. The thermoelectric effect refers to the direct energy conversion between heat and electricity.

[0003] Thermoelectric devices are a general term for devices that utilize the thermoelectric effect, and they have a structure in which P-type thermoelectric arms and N-type thermoelectric arms are joined between metal electrodes to form PN junction pairs.

[0004] Thermoelectric devices can be classified into devices that utilize the change in resistance with temperature, devices that utilize the Seebeck effect (which generates an electromotive force due to a temperature difference), and devices that utilize the Peltier effect (which generates heat absorption or release due to current, etc.).

[0005] Thermoelectric devices are widely used in household appliances, electronic components, and communication devices. For example, thermoelectric devices can be used in cooling equipment, heating equipment, and power generation equipment. Therefore, the demand for the thermoelectric performance of thermoelectric devices is gradually increasing.

[0006] A thermoelectric device includes a substrate, electrodes, and thermoelectric arms. Multiple thermoelectric arms are disposed between an upper substrate and a lower substrate, multiple upper electrodes are disposed between the multiple thermoelectric arms and the upper substrate, and multiple lower electrodes are disposed between the multiple thermoelectric arms and the lower substrate.

[0007] In order to improve the heat conduction performance of thermoelectric devices, metal substrates are being used more and more often.

[0008] Typically, thermoelectric devices are manufactured by sequentially depositing a resin layer, electrodes, and thermoelectric arms onto a prepared metal substrate. While using a metal substrate offers advantages in terms of heat conduction, it also presents a problem of reduced reliability over long-term use due to low voltage withstand capability.

[0009] To address this issue, attempts were made to improve voltage resistance by oxidizing the surface of the metal substrate. However, since the heat sink needs to be bonded to the substrate on the high-temperature side, there is a problem in bonding the oxidized metal substrate to the heat sink.

[0010] Therefore, there is a need for a thermoelectric device that not only has improved thermal conductivity but also improved voltage withstand performance and bonding performance with heat sinks. Summary of the Invention

[0011] Technical issues

[0012] The purpose of this invention is to provide a structure for a substrate and insulating layer of a thermoelectric device, which has improved thermal conductivity, voltage resistance, and bonding performance with a heat sink.

[0013] Technical solution

[0014] One aspect of the present invention provides a thermoelectric device, comprising: a first insulating layer; a first substrate disposed on the first insulating layer; a second insulating layer disposed on the first substrate; a first electrode disposed on the second insulating layer; a P-type thermoelectric arm and an N-type thermoelectric arm disposed on the first electrode; a second electrode disposed on the P-type thermoelectric arm and the N-type thermoelectric arm; a third insulating layer disposed on the second electrode; and a second substrate disposed on the third insulating layer, wherein the first insulating layer includes a first alumina layer, the first substrate is an aluminum substrate, the second substrate is a copper substrate, the first substrate is a low-temperature portion, and the second substrate is a high-temperature portion.

[0015] Each of the second and third insulating layers may be formed as a resin layer comprising at least one of an epoxy resin composition and a silicone resin composition.

[0016] The thickness of the second insulating layer can be equal to or less than the thickness of the third insulating layer.

[0017] The second insulating layer may include a second alumina layer, and the third insulating layer may include a resin layer, which includes at least one of an epoxy resin composition and a silicone resin composition.

[0018] The second insulating layer may further include a resin layer disposed on the second alumina layer and comprising at least one of an epoxy resin composition and a silicone resin composition.

[0019] The thickness of the resin layer included in the second insulating layer may be less than the thickness of either the second alumina layer or the third insulating layer.

[0020] At least one of the first alumina layer and the second alumina layer can be formed by anodizing an aluminum substrate.

[0021] At least one of the first alumina layer and the second alumina layer may extend along the side surface of the aluminum substrate and may be connected to the other of the first alumina layer and the second alumina layer.

[0022] The sum of the thickness of the first insulating layer and the thickness of the second insulating layer can be 80 μm or more.

[0023] The thermoelectric device may further include a heat sink disposed on a copper substrate.

[0024] An oxide layer can be omitted between the copper substrate and the heat sink.

[0025] Beneficial effects

[0026] According to embodiments of the present invention, thermoelectric devices with high performance and high reliability can be obtained. In particular, according to embodiments of the present invention, thermoelectric devices with not only improved thermal conductivity but also improved voltage withstand performance and heat sink bonding performance can be obtained.

[0027] Furthermore, according to embodiments of the present invention, a thermoelectric device that satisfies the performance difference between the low-temperature portion and the high-temperature portion can be obtained.

[0028] The thermoelectric device according to embodiments of the present invention can be applied not only to applications formed in small sizes, but also to applications formed in large sizes, such as vehicles, ships, steel mills, incinerators, etc. Attached Figure Description

[0029] Figure 1 This shows a cross-sectional view of the thermoelectric device. Figure 2 This is a perspective view showing a thermoelectric device.

[0030] Figure 3 This is a perspective view showing a thermoelectric device including a sealing component.

[0031] Figure 4 This is an exploded perspective view showing a thermoelectric device including a sealing member.

[0032] Figure 5 This is a cross-sectional view showing a thermoelectric device according to an embodiment of the present invention.

[0033] Figure 6 This is a cross-sectional view showing a thermoelectric device according to another embodiment of the present invention.

[0034] Figure 7 This is a cross-sectional view showing a thermoelectric device according to yet another embodiment of the present invention.

[0035] Figure 8 This is a cross-sectional view showing a thermoelectric device according to another embodiment of the present invention. Figure 9 This is a cross-sectional view showing a thermoelectric device according to yet another embodiment of the present invention.

[0036] Figure 10 This is a graph showing the results of simulating the withstand voltage based on the thickness of the insulation layer.

[0037] Figure 11 The graph shows the simulation results of the thermal resistance variation according to the thickness of the insulating layer in each structure of the comparative example, example 2 and example 3. Detailed Implementation

[0038] In the following, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0039] However, the inventive concept is not limited to the certain embodiments described herein, but can be implemented in various other forms. Within the scope of the inventive concept, at least one component in the embodiments may be selectively combined, substituted, and used.

[0040] Furthermore, unless otherwise explicitly and specifically defined in the context, all terms used herein (including technical and scientific terms) are to be interpreted as having the meaning commonly understood by those skilled in the art. General terms (e.g., terms defined in dictionaries) should be interpreted with consideration of their meaning in the context of the relevant art.

[0041] Furthermore, the terminology used in the embodiments of the present invention is for describing the embodiments and is not intended to limit the present invention.

[0042] In this specification, unless the context clearly indicates otherwise, the singular form may include its plural form. In the case of describing "at least one (or more) of A, B, and C", it may include at least one combination of all possible combinations of A, B, and C.

[0043] In addition, when describing the components of embodiments of the present invention, terms such as "first", "second", "A", "B", "(a)", "(b)" may be used.

[0044] These terms are used only to distinguish one element from other elements, and the nature, order, etc., of the elements are not limited by these terms.

[0045] In addition, it should be understood that when an element is described as being “connected or coupled” to another element, such a description may include not only cases where the element is directly connected or coupled to another element, but also cases where the element and another element are “connected or coupled” through another element disposed between them.

[0046] Furthermore, when any element is described as being formed or disposed "above or below" another element, such a description includes not only cases where the two elements are formed or disposed in direct contact with each other, but also cases where one or more other elements are disposed between the two elements. Additionally, when an element is described as being disposed "above or below" another element, such a description can include cases where one element is disposed on the upper or lower side relative to the other element.

[0047] Figure 1 This shows a cross-sectional view of the thermoelectric device. Figure 2 This is a perspective view showing a thermoelectric device. Figure 3This is a perspective view showing a thermoelectric device including a sealing member. Figure 4 This is an exploded perspective view showing a thermoelectric device including a sealing member.

[0048] refer to Figure 1 and Figure 2 The thermoelectric device 100 includes a lower substrate 110, a lower electrode 120, a P-type thermoelectric arm 130, an N-type thermoelectric arm 140, an upper electrode 150, and an upper substrate 160.

[0049] A lower electrode 120 is disposed between the lower substrate 110 and the lower surfaces of the P-type thermoelectric arm 130 and the N-type thermoelectric arm 140, and an upper electrode 150 is disposed between the upper substrate 160 and the upper surfaces of the P-type thermoelectric arm 130 and the N-type thermoelectric arm 140. Therefore, multiple P-type thermoelectric arms 130 and multiple N-type thermoelectric arms 140 are electrically connected through the lower electrode 120 and the upper electrode 150. A pair of P-type thermoelectric arms 130 and N-type thermoelectric arms 140 disposed between the lower electrode 120 and the upper electrode 150 and electrically connected to each other can form a unit cell.

[0050] For example, when a voltage is applied to the lower electrode 120 and the upper electrode 150 via leads 181 and 182, due to the Peltier effect, the substrate through which current flows from the P-type thermoelectric arm 130 to the N-type thermoelectric arm 140 can absorb heat to serve as a cooling component, and the substrate through which current flows from the N-type thermoelectric arm 140 to the P-type thermoelectric arm 130 can be heated to serve as a heating component. Alternatively, when a temperature difference is applied between the lower electrode 120 and the upper electrode 150, due to the Seebeck effect, charge can move through the P-type thermoelectric arm 130 and the N-type thermoelectric arm 140, thereby generating electricity.

[0051] In this configuration, each of the P-type thermoelectric arm 130 and the N-type thermoelectric arm 140 may be a bismuth telluride (Bi-Te) type thermoelectric arm primarily comprising Bi and Te. The P-type thermoelectric arm 130 may be a Bi-Te type thermoelectric arm comprising at least one of antimony (Sb), nickel (Ni), aluminum (Al), copper (Cu), silver (Ag), lead (Pb), boron (B), gallium (Ga), Te, Bi, and indium (In). For example, based on a total weight of 100 wt%, the P-type thermoelectric arm 130 may comprise 99 wt% to 99.999 wt% Bi-Sb-Te (which is the main material) and 0.001 wt% to 1 wt% of at least one of Ni, Al, Cu, Ag, Pb, B, Ga, and In. The N-type thermoelectric arm 140 may be a Bi-Te type thermoelectric arm comprising at least one of Se, Ni, Cu, Ag, Pb, B, Ga, Te, Bi, and In. For example, based on a total weight of 100 wt%, the N-type thermoelectric arm 140 may include 99 wt% to 99.999 wt% of Bi-Se-Te (which is the main material) and 0.001 wt% to 1 wt% of at least one of Ni, Al, Cu, Ag, Pb, B, Ga and In.

[0052] Each of the P-type thermoelectric arm 130 and the N-type thermoelectric arm 140 can be formed as a bulk type or a stacked type. Typically, the bulk P-type thermoelectric arm 130 or the bulk N-type thermoelectric arm 140 can be formed by a process in which the thermoelectric material is heat-treated to produce an ingot, the ingot is ground and sieved to obtain powder for the thermoelectric arm, the powder is sintered, and the sintered body is cut. In this case, each of the P-type thermoelectric arm 130 and the N-type thermoelectric arm 140 can be a polycrystalline thermoelectric arm. When the powder for the thermoelectric arm is sintered to manufacture a polycrystalline thermoelectric arm, the powder can be compressed at 100 MPa to 200 MPa. For example, when sintering the P-type thermoelectric arm 130, the powder for the thermoelectric arm can be sintered at 100 to 150 MPa, preferably 110 to 140 MPa, and more preferably 120 to 130 MPa. Furthermore, when sintering the N-type thermoelectric arm 130, the powder for the thermoelectric arm can be sintered at 150 to 200 MPa, preferably 160 to 195 MPa, and more preferably 170 to 190 MPa. As described above, when each of the P-type thermoelectric arm 130 and the N-type thermoelectric arm 140 is a polycrystalline thermoelectric arm, the strength of the P-type thermoelectric arm 130 and the N-type thermoelectric arm 140 can be improved. The stacked P-type thermoelectric arm 130 or the stacked N-type thermoelectric arm 140 can be formed in a process in which a paste containing thermoelectric material is applied to a respective sheet-like substrate to form a unit component, and the unit components are stacked and cut.

[0053] In this case, the P-type thermoelectric arm 130 and the N-type thermoelectric arm 140 can have the same shape and volume, or they can have different shapes and volumes. For example, since the P-type thermoelectric arm 130 and the N-type thermoelectric arm 140 have different electrical conductivity characteristics, the height or cross-sectional area of ​​the N-type thermoelectric arm 140 can be different from that of the P-type thermoelectric arm 130.

[0054] In this case, the P-type thermoelectric arm 130 or the N-type thermoelectric arm 140 can be cylindrical, polygonal, elliptical, etc.

[0055] Alternatively, the P-type thermoelectric arm 130 or the N-type thermoelectric arm 140 can also have a stacked structure. For example, the N-type or P-type thermoelectric arm can be formed by stacking and cutting multiple structures (in which semiconductor material is applied to each of a sheet-like substrate member). This prevents material loss and improves electrical conductivity. The structure may further include a conductive layer with an open pattern, thus increasing the adhesion between structures, potentially reducing thermal conductivity, and potentially increasing electrical conductivity.

[0056] Alternatively, the P-type thermoelectric arm 130 or the N-type thermoelectric arm 140 can be configured such that the cross-sectional areas within a single thermoelectric arm are different. For example, in a thermoelectric arm, the cross-sectional area of ​​the two ends facing the electrodes is larger than the cross-sectional area between the two ends. Therefore, since the temperature difference between the two ends can be large, thermoelectric efficiency can be improved.

[0057] The performance of a thermoelectric device according to an embodiment of the present invention can be expressed as a figure of merit (ZT). The figure of merit (ZT) can be represented by Equation 1.

[0058] [Equation 1]

[0059]

[0060] Here, α represents the Seebeck coefficient [V / K], σ represents the conductivity [S / m], and α 2 σ represents the power factor [W / mK] 2 Additionally, T represents temperature, and k represents thermal conductivity [W / mK]. k can be expressed as a·cp·ρ, where a represents thermal diffusivity [cm]. 2 / S], cp represents specific heat [J / gK], ρ represents density [g / cm³] 3 ].

[0061] To obtain the thermoelectric performance index (ZT) of a thermoelectric device, the Z value (V / K) is measured using a Z meter, and the thermoelectric performance index (ZT) can be calculated using the measured Z value.

[0062] In this configuration, each of the lower electrode 120 disposed between the lower substrate 110 and the P-type thermoelectric arm 130 and the N-type thermoelectric arm 140, and the upper electrode 150 disposed between the upper substrate 160 and the P-type thermoelectric arm 130 and the N-type thermoelectric arm 140, may include at least one of Cu, Ag, Al, and Ni, and may have a thickness of 0.01 mm to 0.3 mm. When the thickness of the lower electrode 120 or the upper electrode 150 is less than 0.01 mm, its electrode function deteriorates, potentially reducing its conductivity; conversely, when its thickness is greater than 0.3 mm, its resistance increases, thus potentially reducing its conductivity.

[0063] Furthermore, the lower substrate 110 and the upper substrate 160 can be metal substrates facing each other, and the thickness of each of the lower substrate 110 and the upper substrate 160 can be in the range of 0.1 mm to 1.5 mm. When the thickness of the metal substrate is less than 0.1 mm or greater than 1.5 mm, the reliability of the thermoelectric device may be reduced because the thermal radiation characteristics or thermal conductivity may become too high. Additionally, when the lower substrate 110 and the upper substrate 160 are metal substrates, an insulating layer 170 can be formed between the lower substrate 110 and the lower electrode 120, and between the upper substrate 160 and the upper electrode 150. The insulating layer 170 can include a material with a thermal conductivity of 5 to 20 W / K.

[0064] In this case, the dimensions of the lower substrate 110 and the upper substrate 160 can also be different. For example, the volume, thickness, or area of ​​one of the lower substrate 110 and the upper substrate 160 can be larger than the volume, thickness, or area of ​​the other. Therefore, the heat absorption or heat radiation performance of the thermoelectric device can be improved. Preferably, at least one of the volume, thickness, and area of ​​the lower substrate 110 can be larger than the corresponding one of the upper substrate 160. In this case, compared with the case where the lower substrate 110 is placed in a high-temperature region for the Seebeck effect or a sealing member is provided on the lower substrate 110 to protect the thermoelectric module described below from the influence of the external environment, when the lower substrate 110 is placed in a high-temperature region for the Seebeck effect, at least one of the volume, thickness, and area of ​​the lower substrate 110 can be larger than the corresponding one of the upper substrate 160. In this case, the area of ​​the lower substrate 110 can be 1.2 to 5 times the area of ​​the upper substrate 160. When the area of ​​the lower substrate 110 is less than 1.2 times the area of ​​the upper substrate 160, the effect on improving the heat conduction efficiency is not significant. When the area of ​​the lower substrate 110 is more than 1.2 times the area of ​​the upper substrate 160, the heat conduction efficiency is significantly reduced, and it may be difficult to maintain the basic shape of the thermoelectric module.

[0065] Additionally, a thermal radiation pattern, such as an embossed pattern, can be formed on the surface of at least one of the lower substrate 110 and the upper substrate 160. Therefore, the thermal radiation performance of the thermoelectric device can be improved. When an embossed pattern is formed on the surface in contact with the P-type thermoelectric arm 130 or the N-type thermoelectric arm 140, the bonding performance between the thermoelectric arm and the substrate can be improved. The thermoelectric device 100 includes a lower substrate 110, a lower electrode 120, a P-type thermoelectric arm 130, an N-type thermoelectric arm 140, an upper electrode 150, and an upper substrate 160.

[0066] like Figure 3 and Figure 4As shown, a sealing member 190 can be further provided between the lower substrate 110 and the upper substrate 160. The sealing member can be provided on the side surface of the lower electrode 120, the P-type thermoelectric arm 130, the N-type thermoelectric arm 140, and the upper electrode 150 between the lower substrate 110 and the upper substrate 160. Therefore, the lower electrode 120, the P-type thermoelectric arm 130, the N-type thermoelectric arm 140, and the upper electrode 150 can be sealed to prevent them from being exposed to moisture, heat, and contamination from the outside. In this case, the sealing member 190 may include: a sealing housing 192, which is configured to be spaced apart from the outermost surfaces of the plurality of lower electrodes 120, the plurality of P-type thermoelectric arms 130, the plurality of N-type thermoelectric arms 140, and the plurality of upper electrodes 150 by a predetermined distance; a sealing material 194, which is provided between the sealing housing 192 and the lower substrate 110; and a sealing material 196, which is provided between the sealing housing 192 and the upper substrate 160. As described above, the sealing housing 192 can contact the lower substrate 110 and the upper substrate 160 through sealing materials 194 and 196. Therefore, the following problem can be prevented: when the sealing housing 192 is in direct contact with the lower substrate 110 and the upper substrate 160, heat conduction occurs through the sealing housing 192, thus reducing the temperature difference between the lower substrate 110 and the upper substrate 160. In this case, each of the sealing materials 194 and 196 may include at least one of epoxy resin and silicone resin, or a tape with at least one of epoxy resin and silicone resin coated on both surfaces. Sealing materials 194 and 196 can be used to hermetically seal the gaps between the sealing housing 192 and the lower substrate 110 and between the sealing housing 192 and the upper substrate 160, respectively, improving the sealing effect of the lower electrode 120, the P-type thermoelectric arm 130, the N-type thermoelectric arm 140, and the upper electrode 150, and can be interchanged with decorative materials, decorative layers, waterproof materials, waterproof layers, etc. In this configuration, sealing material 194, which seals the gap between the sealing housing 192 and the lower substrate 110, can be disposed on the lower substrate 110, and sealing material 196, which seals the gap between the sealing housing 192 and the upper substrate 160, can be disposed on the side surface of the upper substrate 160. Therefore, the area of ​​the lower substrate 110 can be larger than the area of ​​the upper substrate 160. Simultaneously, guide grooves G through which the leads 180 and 182 connected to the electrodes pass can be formed in the sealing housing 192. Therefore, the sealing housing 192 can be an injection-molded part made of plastic and can be used interchangeably with a sealing cap. However, the above description of the sealing member is merely exemplary, and the sealing member can be modified in various forms. Although not shown in the drawings, an insulator may be further included such that it surrounds the sealing member. Alternatively, the sealing member may further include an insulating component.

[0067] Meanwhile, the P-type thermoelectric arm 130 and the N-type thermoelectric arm 140 can have Figure 1A or Figure 1 The structure shown in B. (Refer to...) Figure 1 A. Thermoelectric arms 130 and 140 may each include thermoelectric material layers 132 and 142, first plating layers 134-1 and 144-1 stacked on one surface of the thermoelectric material layers 132 and 142, and second plating layers 134-2 and 144-2 stacked on another surface of the thermoelectric material layers 132 and 142 opposite to the first surface. Alternatively, refer to Figure 1 B. Thermoelectric arms 130 and 140 may respectively include thermoelectric material layers 132 and 142, first plating layers 134-1 and 144-1 stacked on one surface of thermoelectric material layers 132 and 142, second plating layers 134-2 and 144-2 stacked on another surface of thermoelectric material layers 132 and 142 opposite to the first surface, first buffer layers 136-1 and 146-1 disposed between thermoelectric material layers 132 and 142 and the first plating layers 134-1 and 144-1, and second buffer layers 136-2 and 146-2 disposed between thermoelectric material layers 132 and 142 and the second plating layers 134-2 and 144-2. Alternatively, thermoelectric arms 130 and 140 may further include metal layers stacked between the first plating layers 134-1 and 144-1 and the lower substrate 110, and metal layers stacked between the second plating layers 134-2 and 144-2 and the upper substrate 160, respectively.

[0068] In this case, each of the thermoelectric material layers 132 and 142 may include Bi and Te as semiconductor materials. The material or shape of the thermoelectric material layers 132 and 142 may be the same as that of the P-type thermoelectric arm 130 or the N-type thermoelectric arm 140 described above. When the thermoelectric material layers 132 and 142 are polycrystalline layers, the bonding strength between the thermoelectric material layers 132 and 142, the first buffer layers 136-1 and 146-1, and the first plating layers 134-1 and 144-1, as well as the bonding strength between the thermoelectric material layers 132 and 142, the second buffer layers 136-2 and 146-2, and the second plating layers 134-2 and 144-2, can be increased. Therefore, even when the thermoelectric device 100 is applied to applications such as vehicles that experience vibration, it can prevent the first coatings 134-1 and 144-1 and the second coatings 134-2 and 144-2 from separating from the P-type thermoelectric arm 130 or the N-type thermoelectric arm 140 and carbonizing, and can improve the durability and reliability of the thermoelectric device 100.

[0069] In addition, the metal layer may include Cu, Cu alloy, Al or Al alloy and may have a thickness of 0.1 mm to 0.5 mm, and preferably 0.2 mm to 0.3 mm.

[0070] Next, each of the first plating layers 134-1 and 144-1 and the second plating layers 134-2 and 144-2 may include at least one of Ni, Sn, Ti, Fe, Sb, Cr, and Mo and may have a thickness of 1 μm to 20 μm, and preferably 1 μm to 10 μm. Since the first plating layers 134-1 and 144-1 and the second plating layers 134-2 and 144-2 prevent the reaction between the semiconductor material Bi or Te in the thermoelectric material layers 132 and 142 and the metal layer, the first plating layers 134-1 and 144-1 and the second plating layers 134-2 and 144-2 not only prevent the performance degradation of the thermoelectric device but also prevent the oxidation of the metal layer.

[0071] In this configuration, the first buffer layers 136-1 and 146-1 may be disposed between the thermoelectric material layers 132 and 142 and the first plating layers 134-1 and 144-1, and the second buffer layers 136-2 and 146-2 may be disposed between the thermoelectric material layers 132 and 142 and the second plating layers 134-2 and 144-2. In this configuration, each of the first buffer layers 136-1 and 146-1 and the second buffer layers 136-2 and 146-2 may include Te. For example, each of the first buffer layers 136-1 and 146-1 and the second buffer layers 136-2 and 146-2 may include at least one of Ni-Te, Sn-Te, Ti-Te, Fe-Te, Sb-Te, Cr-Te, and Mo-Te. According to an embodiment of the present invention, when first buffer layers 136-1 and 146-1, each containing Te, are disposed between thermoelectric material layers 132 and 142 and first plating layers 134-1 and 144-1, and when second buffer layers 136-2 and 146-2, each containing Te, are disposed between thermoelectric material layers 132 and 142 and second plating layers 134-2 and 144-2, it is possible to prevent Te in thermoelectric material layers 132 and 142 from diffusing into the first plating layers 134-1 and 144-1 and the second plating layers 134-2 and 144-2. Therefore, the problem of increased resistance in the thermoelectric material layers due to Bi-rich regions can be prevented.

[0072] As described above, although terms such as lower substrate 110, lower electrode 120, upper electrode 150 and upper substrate 160 have been used, “upper” and “lower” are used arbitrarily for ease of understanding and description only, and their positions can be reversed, such that the lower substrate 110 and lower electrode 120 are disposed at the upper part, while the upper electrode 150 and upper substrate 160 are disposed at the lower part.

[0073] Figure 5 This is a cross-sectional view showing a thermoelectric device according to an embodiment of the present invention. Figure 6 This is a cross-sectional view showing a thermoelectric device according to another embodiment of the present invention. Figure 7This is a cross-sectional view showing a thermoelectric device according to yet another embodiment of the present invention. Figure 8 This is a cross-sectional view showing a thermoelectric device according to another embodiment of the present invention. Figure 9 This is a cross-sectional view showing a thermoelectric device according to yet another embodiment of the present invention. References will be omitted. Figures 1 to 4 Repeated descriptions of content that are identical.

[0074] refer to Figures 5 to 7 The thermoelectric device 300 according to an embodiment of the present invention includes a first insulating layer 310, a first substrate 320 disposed on the first insulating layer 310, a second insulating layer 330 disposed on the first substrate 320, a plurality of first electrodes 340 disposed on the second insulating layer 330, a plurality of P-type thermoelectric arms 350 and a plurality of N-type thermoelectric arms 355 disposed on the plurality of first electrodes 340, a plurality of second electrodes 360 disposed on the plurality of P-type thermoelectric arms 350 and the plurality of N-type thermoelectric arms 355, 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. As shown in the figure, a heat sink 390 may be further disposed on the second substrate 380. Although not shown in the figure, a sealing member may be further disposed between the first substrate 320 and the second substrate 380.

[0075] In this case, the first electrode 340, the P-type thermoelectric arm 350, the N-type thermoelectric arm 355, and the second electrode 360 ​​can respectively correspond to the referenced... Figure 1 and Figure 2 The upper electrode 150, P-type thermoelectric arm 130, N-type thermoelectric arm 140, and lower electrode 120 are described, and their contents are consistent with the reference. Figure 1 and Figure 2 The content described is the same or similar.

[0076] Typically, since the power supply is connected to the electrode located on the low-temperature side of the thermoelectric device 300, a higher voltage withstand capability may be required on the high-temperature side compared to the low-temperature side. In this case, it is shown that the positive (+) terminal and the negative (-) terminal are connected to the first electrode 340, pass through the first insulating layer 310, the first substrate 320 and the second insulating layer 330, and extend downward. However, the invention is not limited to this. The positive (+) terminal and the negative (-) terminal may be connected to the first electrode 340 and may extend laterally on the first insulating layer 310, the first substrate 320 and the second insulating layer 330.

[0077] Conversely, when the thermoelectric device 300 is activated, since the high-temperature portion of the thermoelectric device 300 may be exposed to high temperatures, such as above approximately 180°C, delamination between the electrodes, insulating layer, and substrate may occur due to differences in the coefficients of thermal expansion between them. Therefore, the high-temperature portion of the thermoelectric device 300 may require higher thermal conductivity compared to the low-temperature portion. In particular, when a heat sink is further provided on the substrate on the high-temperature portion of the thermoelectric device 300, the bonding force between the substrate and the heat sink may significantly affect the durability and reliability of the thermoelectric device 300.

[0078] In the following text, it will be assumed and described that the first substrate 320 is disposed on the low-temperature portion side of the thermoelectric device 300 and the second substrate 380 is disposed on the high-temperature portion side of the thermoelectric device 300.

[0079] According to an embodiment of the present invention, the first substrate 320 is formed as an aluminum substrate, and the second substrate 380 is formed as a copper substrate. The copper substrate has higher thermal conductivity and electrical conductivity than the aluminum substrate. Therefore, when the first substrate 320 is formed as an aluminum substrate and the second substrate 380 is formed as a copper substrate, both high voltage withstand performance on the low-temperature side and high thermal radiation performance on the high-temperature side can be satisfied.

[0080] Furthermore, a first substrate 320 is disposed on a first insulating layer 310, and a second insulating layer 330 is disposed on a first substrate 320. As described above, when insulating layers are disposed on both surfaces of the first substrate 320, the voltage withstand performance of one side of the first substrate 320 can be further improved.

[0081] In this case, the first insulating layer 310 can be a first alumina layer. When the first insulating layer 310 is a first alumina layer, the voltage withstand performance on the first substrate 320 side can be improved even without increasing the thermal resistance of the first substrate 320. In this case, the thickness of the first insulating layer 310 can be in the range of 20 μm to 100 μm, preferably in the range of 30 μm to 80 μm, and more preferably in the range of 35 μm to 60 μm. When the thickness of the first insulating layer 310 meets the above numerical range, both high thermal conductivity and high voltage withstand performance can be simultaneously achieved.

[0082] In this case, the total thickness of the insulating layer on the first substrate 320 side, i.e., the sum of the thickness of the first insulating layer 310 and the thickness of the second insulating layer 330, can be 80 μm or more, more preferably 80 μm to 480 μm. Generally, as the thickness of the insulating layer increases, the voltage withstand performance can be improved. However, as the thickness of the insulating layer increases, the thermal resistance increases. However, in the embodiments of the present invention, since the insulating layers on the first substrate 320 side are respectively disposed on both sides of the first substrate 320, and in particular, the alumina layer is disposed below the first substrate 320, both high thermal conductivity and high voltage withstand performance can be simultaneously achieved.

[0083] At the same time, such as Figure 3 As shown, each of the second insulating layer 330 and the third insulating layer 370 may be a resin layer comprising at least one of an epoxy resin composition and a silicone resin composition, wherein the epoxy resin composition comprises an epoxy resin and an inorganic filler, and the silicone resin composition comprises polydimethylsiloxane (PDMS). Therefore, the second insulating layer 330 can improve the insulation performance, bonding strength, and thermal conductivity between the first substrate 320 and the first electrode 340, while the third insulating layer 370 can improve the insulation performance, bonding strength, and thermal conductivity between the second electrode 360 ​​and the second substrate 380.

[0084] In this case, inorganic fillers can be included in the resin layer at 68 to 88% by volume. When inorganic fillers are included in the resin layer at less than 68% by volume, the thermal conductivity may be low, while when inorganic fillers are included in the resin layer at more than 88% by volume, the resin layer may be prone to cracking.

[0085] Additionally, the epoxy resin may include an epoxy compound and a hardener. In this case, based on a 10:1 volume ratio of the epoxy compound, a hardener may be included in the range of 1 to 10 volume ratios. In this case, the epoxy compound may include at least one of crystalline epoxy compounds, amorphous epoxy compounds, and organosilicon epoxy compounds. The inorganic filler may include alumina and nitrides, and the nitride may be included therein at 55 to 95 wt%, more preferably 60 to 80 wt%, of the inorganic filler. When the nitride is included therein in the above-mentioned numerical range, thermal conductivity and bonding strength can be improved. In this case, the nitride may include at least one of boron nitride and aluminum nitride.

[0086] In this case, the particle size D50 of the boron nitride agglomerates can be in the range of 250 μm to 350 μm, and the particle size D50 of the alumina can be in the range of 10 μm to 30 μm. When the particle size D50 of both the boron nitride and alumina meets the above values, the boron nitride and alumina can be uniformly distributed in the resin layer. Therefore, the entire resin layer can have uniform thermal conductivity and bonding performance.

[0087] In this case, it is advantageous to maintain the insulation and bonding properties between the first substrate 320 and the first electrode 340 while making the second insulating layer 330, which is a resin layer, as thin as possible in terms of thermal conductivity. According to an embodiment of the invention, since the first insulating layer 310, which is an alumina layer, is disposed together with the second insulating layer 330 when the first substrate 320 is inserted between it and the second insulating layer 330, sufficient voltage withstand performance can be achieved on the low-temperature portion side even when the thickness of the second insulating layer 330, which is a resin layer, is equal to or less than the thickness of the third insulating layer 370 formed from the same material as the second insulating layer 330. Therefore, the thickness of the second insulating layer 330, which is a resin layer, can be equal to or less than the thickness of the third insulating layer 370.

[0088] Specifically, the thickness of the third insulating layer 370 can be greater than the thickness of the second insulating layer 330. As described above, when the thermoelectric device 300 is driven, the temperature on the high-temperature portion side can rise to about 180°C or higher, and when the third insulating layer 370 is formed as a flexible resin layer according to an embodiment of the present invention, the third insulating layer 370 can be used to mitigate the thermal shock between the second electrode 360 ​​and the second substrate 380.

[0089] At the same time, refer to Figure 6 The second insulating layer 330 may include a second alumina layer, and the third insulating layer 370 may be formed as a resin layer comprising at least one of an epoxy resin composition and a silicone resin composition, wherein the epoxy resin composition comprises an epoxy resin and an inorganic filler, and the silicone resin composition comprises PDMS (polydimethylsiloxane). As described above, voltage withstand performance is more important on the low-temperature side, while bonding performance is more important on the high-temperature side. Therefore, when the second insulating layer 330 is formed as a resin layer, the second insulating layer 330 can have higher voltage withstand performance than when the second insulating layer 330 is formed as a second alumina layer. Furthermore, when the third insulating layer 370 is formed as a resin layer, bonding performance between the second electrode 360 ​​and the second substrate 380 can be ensured.

[0090] Alternatively, refer to Figure 7The second insulating layer 330 includes a second alumina layer 334 disposed on the first substrate 320, and may further include a resin layer 332 disposed on the second alumina layer 334. In this case, the resin layer 332 included in the second insulating layer 330 can improve the bonding force between the second alumina layer 334 and the first electrode 340. That is, since the resin layer 332 included in the second insulating layer 330 is formed to provide bonding force only between the second alumina layer 334 and the first electrode 340, the thickness of the resin layer 332 of the second insulating layer 330 can be less than the thickness of the second alumina layer 334 and the thickness of the third insulating layer 370.

[0091] As described above, according to embodiments of the present invention, a thermoelectric device can be obtained in which the structure of the substrate and the insulating layer is modified to correspond to the characteristic differences between the low-temperature and high-temperature portions of the thermoelectric device.

[0092] In this case, at least one of the first alumina layer and the second alumina layer 334 can be formed by anodizing the aluminum substrate serving as the first substrate 320. Alternatively, at least one of the first alumina layer and the second alumina layer 334 can also be formed using a dipping process or a spraying process.

[0093] At the same time, such as Figure 8 and Figure 9 As shown, an extension formed from at least one of the first alumina layer and the second alumina layer 334 extending along the aluminum substrate (i.e., the first substrate 320) can connect the first alumina layer and the second alumina layer 334 on the side surface of the aluminum substrate. Therefore, an alumina layer can be formed on the entire surface of the aluminum substrate, and the voltage withstand performance of the low-temperature portion side can be further improved.

[0094] Meanwhile, as described above, a heat sink can be further provided on the high-temperature portion side. The second substrate 380 and the heat sink 390 on the high-temperature portion side can be integrally formed, but they can also be joined separately. In this case, when a metal oxide layer is formed on the second substrate 380, it may be difficult to join the second substrate 380 to the heat sink 390. Therefore, in order to improve the bonding strength between the second substrate 380 and the heat sink 390, a metal oxide layer may not be formed between the second substrate 380 and the heat sink 390. That is, when the second substrate 380 is a copper substrate, a copper oxide layer may not be formed on the copper substrate. For this purpose, the copper substrate can be pre-treated to prevent oxidation. For example, when the copper substrate is plated with a nickel metal layer that is less prone to oxidation than copper, the formation of a metal oxide layer on the copper substrate can be prevented.

[0095] As described above, according to embodiments of the present invention, a thermoelectric device can be obtained in which the structures of the substrate and insulating layer on the low-temperature side and the substrate and insulating layer on the high-temperature side are different to correspond to the characteristic differences between the low-temperature and high-temperature parts of the thermoelectric device.

[0096] Table 1 and Figure 10 Simulation results of withstand voltage based on the thickness of the insulating layer are shown. The insulating layer is formed by anodizing an aluminum substrate, and the withstand voltage is measured based on the thickness of the insulating layer.

[0097] [Table 1]

[0098]

[0099] Refer to Table 1 and Figure 10 As can be seen, the withstand voltage performance improves with increasing insulation layer thickness. In particular, when the insulation layer thickness is above 80μm, a withstand voltage performance of over 3.6kV can be achieved.

[0100] Table 2 shows the measured thermal resistance of each thermoelectric device according to the comparative examples and embodiments.

[0101] In the comparative examples, an insulating layer formed as a resin layer is disposed on a copper substrate. In Example 1, an aluminum substrate is disposed on an aluminum oxide layer, and an insulating layer formed as a resin layer is further disposed on the aluminum substrate. In Example 2, an aluminum oxide layer is disposed on both surfaces of the aluminum substrate. In Example 3, an aluminum oxide layer is disposed on both surfaces of the aluminum substrate, and an insulating layer formed as a resin layer is further disposed on the aluminum oxide layer.

[0102] [Table 2]

[0103]

[0104] Referring to Table 2, in the comparative examples, it can be seen that although the total thickness of the insulating layer is 40 μm, which is less than the total thickness of each insulating layer in Examples 1 to 3, the insulating layer has a higher thermal resistance than each insulating layer in Examples 1-3. Furthermore, it can be seen that the thermal resistance of each of Examples 2 and 3, where an aluminum oxide layer is provided on both surfaces of the aluminum substrate, is significantly lower than that of Example 1, where the aluminum oxide layer is only provided on one surface of the aluminum substrate. Additionally, in Example 3, where a resin layer is further provided on the aluminum oxide layer, although the thermal resistance is similar compared to Example 2, the bonding performance between the aluminum substrate and the electrode can be higher.

[0105] at the same time, Figure 11 Simulation results of thermal resistance based on the thickness of the insulating layer are shown for each structure according to the comparative example, example 2, and example 3.

[0106] refer to Figure 11 In the structures of the comparative examples and Example 3, it can be seen that the thermal resistance increases sharply with the increase of the resin layer thickness. Conversely, in the structure according to Example 2, it can be seen that even when the thickness of the alumina layer increases to 480 μm, the thermal resistance level is the same as that when the resin layer thickness is 40 μm.

[0107] The thermoelectric device according to this embodiment can be applied to power generation equipment, cooling equipment, heating equipment, etc. Specifically, the thermoelectric device according to the embodiment of the present invention can be mainly applied to optical communication modules, sensors, medical devices, measuring instruments, aerospace industry, refrigerators, chillers, car ventilated seats, cup holders, washing machines, dryers, wine cellars, water purifiers, sensor power supplies, thermopile, etc.

[0108] In this context, as an example of applying a thermoelectric device according to an embodiment of the present invention to a medical device, a polymerase chain reaction (PCR) device is provided. A PCR device is a device that determines the nucleotide sequence of DNA by amplifying deoxyribonucleic acid (DNA) and requires precise temperature control and thermal cycling. Therefore, a Peltier-based thermoelectric device can be applied to its PCR device.

[0109] As another example of the application of the thermoelectric device according to an embodiment of the present invention in a medical device, a photodetector is included. In this case, the photodetector may include an infrared / ultraviolet detector, a charge-coupled device (CCD) sensor, an X-ray detector, a thermoelectric thermal reference source (TTRS), etc. A Peltier-based thermoelectric device can be used to cool the photodetector. Therefore, wavelength changes, output degradation, and resolution degradation due to temperature rise of the photodetector can be prevented.

[0110] Other examples of applications of the thermoelectric device according to embodiments of the present invention in medical devices include the fields of immunoassay, in vitro diagnostics, general temperature control and cooling systems, physical therapy, liquid cooling systems, and blood / plasma temperature control. Therefore, precise temperature control can be performed.

[0111] As another example of the application of the thermoelectric device according to an embodiment of the present invention to a medical device, there is an artificial heart. Therefore, electricity can be applied to the artificial heart.

[0112] Examples of thermoelectric devices according to embodiments of the present invention applied in the aerospace industry include star tracking systems, thermal imaging cameras, infrared / ultraviolet detectors, CCD sensors, the Hubble Space Telescope, and TTRS. Therefore, the temperature of the image sensor can be maintained.

[0113] Other examples of thermoelectric devices applied in the aerospace industry according to embodiments of the present invention include cooling equipment, heaters, power generation equipment, etc.

[0114] Furthermore, the thermoelectric device according to embodiments of the present invention can be applied to power generation, refrigeration, and heating in other industries.

[0115] Although the invention has been shown and described with reference to exemplary embodiments thereof, those skilled in the art will understand that various variations and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A thermoelectric device, comprising: First insulating layer; A first substrate, wherein the first substrate is disposed on the first insulating layer; A second insulating layer is disposed on the first substrate; A first electrode is disposed on the second insulating layer; P-type thermoelectric arm and N-type thermoelectric arm, wherein the P-type thermoelectric arm and the N-type thermoelectric arm are disposed on the first electrode; The second electrode is disposed on the P-type thermoelectric arm and the N-type thermoelectric arm; A third insulating layer is disposed on the second electrode; The second substrate is disposed on the third insulating layer; as well as A heat sink, wherein the heat sink is disposed on the second substrate, The first insulating layer includes a first aluminum oxide layer. The first substrate includes an aluminum substrate. The second substrate includes a copper substrate. The first substrate includes a low-temperature portion. The second substrate includes a high-temperature portion. Each of the second and third insulating layers is formed as a resin layer comprising an epoxy resin composition. The thickness of the second insulating layer is less than the thickness of the third insulating layer, and The surface of the copper substrate disposed between the copper substrate and the heat sink is plated with nickel.

2. The thermoelectric device according to claim 1, wherein, The second insulating layer further includes a second alumina layer disposed between the first substrate and the resin layer.

3. The thermoelectric device according to claim 2, wherein, The thickness of the resin layer included in the second insulating layer is less than the thickness of the second alumina layer.

4. The thermoelectric device according to claim 2, wherein, At least one of the first alumina layer and the second alumina layer is formed by anodizing the aluminum substrate.

5. The thermoelectric device according to claim 2, wherein, At least one of the first alumina layer and the second alumina layer extends along the side surface of the aluminum substrate and is connected to the other of the first alumina layer and the second alumina layer.

6. The thermoelectric device according to claim 1, wherein, The sum of the thickness of the first insulating layer and the thickness of the second insulating layer is 80 μm or more.

7. The thermoelectric device according to claim 1, wherein, The power supply is connected to the first electrode.

8. The thermoelectric device according to claim 7, wherein, The positive and negative terminals of the power supply are connected to the first electrode and extend downward through the second insulating layer, the first substrate, and the first insulating layer.

9. The thermoelectric device according to claim 7, wherein, The positive and negative terminals of the power supply are connected to the first electrode and extend laterally over the first insulating layer, the first substrate, and the second insulating layer.

10. The thermoelectric device according to claim 1, wherein, The thickness of the first insulating layer is 20 μm to 100 μm.

11. The thermoelectric device according to claim 1, wherein, The sum of the thickness of the first insulating layer and the thickness of the second insulating layer is 80 μm to 480 μm.

12. The thermoelectric device according to claim 1, wherein, The resin layer forming the second insulating layer and the resin layer forming the third insulating layer are formed of the same material.

13. A power generation device including a thermoelectric unit, comprising: First insulating layer; A first substrate, wherein the first substrate is disposed on the first insulating layer; A second insulating layer is disposed on the first substrate; A first electrode is disposed on the second insulating layer; P-type thermoelectric arm and N-type thermoelectric arm, wherein the P-type thermoelectric arm and the N-type thermoelectric arm are disposed on the first electrode; The second electrode is disposed on the P-type thermoelectric arm and the N-type thermoelectric arm; A third insulating layer is disposed on the second electrode; The second substrate is disposed on the third insulating layer; as well as A heat sink, wherein the heat sink is disposed on the second substrate, The first insulating layer includes a first aluminum oxide layer. The first substrate includes an aluminum substrate. The second substrate includes a copper substrate. The first substrate includes a low-temperature portion. The second substrate includes a high-temperature portion. Each of the second and third insulating layers is formed as a resin layer comprising an epoxy resin composition. The thickness of the second insulating layer is less than the thickness of the third insulating layer, and The surface of the copper substrate disposed between the copper substrate and the heat sink is plated with nickel.

14. A cooling and heating device including a thermoelectric device, comprising: First insulating layer; A first substrate, wherein the first substrate is disposed on the first insulating layer; A second insulating layer is disposed on the first substrate; A first electrode is disposed on the second insulating layer; P-type thermoelectric arm and N-type thermoelectric arm, wherein the P-type thermoelectric arm and the N-type thermoelectric arm are disposed on the first electrode; The second electrode is disposed on the P-type thermoelectric arm and the N-type thermoelectric arm; A third insulating layer is disposed on the second electrode; The second substrate is disposed on the third insulating layer; as well as A heat sink, wherein the heat sink is disposed on the second substrate, The first insulating layer includes a first aluminum oxide layer. The first substrate includes an aluminum substrate. The second substrate includes a copper substrate. The first substrate includes a low-temperature portion. The second substrate includes a high-temperature portion. Each of the second and third insulating layers is formed as a resin layer comprising an epoxy resin composition. The thickness of the second insulating layer is less than the thickness of the third insulating layer, and The surface of the copper substrate disposed between the copper substrate and the heat sink is plated with nickel.

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