Thermoelectric Module

Abstract

A thermoelectric module according to an embodiment of the present invention includes a thermoelectric element including a first substrate, a first electrode disposed on the first substrate, a semiconductor structure disposed on the first electrode, a second electrode disposed on the semiconductor structure, and a second substrate disposed on the second electrode; a heat sink disposed on the second substrate; and an adhesive layer that bonds the second substrate and the heat sink, wherein the heat sink has a shape in which predetermined patterns are regularly repeated and connected, and each pattern includes a first surface disposed to face the second substrate, a second surface extending upward from one end of the first surface, a third surface extending from the second surface to face the second substrate, and a fourth surface extending upward from another end opposite to the one end of the first surface and connected to the third surface of an adjacent pattern, wherein the distance between the third surface and the second substrate is greater than the distance between the first surface and the second substrate, and the adhesive layer is disposed between the second substrate and the first surface.

Description

[Technical field]

[0001] The present invention relates to thermoelectric modules, and more particularly to bonding a substrate and a heat sink of a thermoelectric element. [Background technology]

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

[0003] A thermoelectric element is a general term for elements that utilize 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 change in electrical resistance due to temperature, elements that use the Seebeck effect, which is a phenomenon in which an electromotive force is generated due to a temperature difference, and elements that use the Peltier effect, which is a phenomenon in which heat is absorbed or generated due to 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. Accordingly, the demand for thermoelectric performance of thermoelectric elements is increasing.

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

[0007] Meanwhile, a heat sink may be disposed on at least one of the two substrates of the thermoelectric device. For this purpose, there have been attempts to form the substrate and the heat sink integrally, but as the area of ​​the substrate increases, it becomes more difficult to maintain a constant flatness, and therefore, in large-area applications, there are difficulties in the manufacturing process of forming the substrate and the heat sink integrally.

[0008] Accordingly, there have been attempts to manufacture the substrate and the heat sink separately and then bond them together using a bonding sheet or by soldering.

[0009] When bonding is performed by soldering, the bonding strength is higher than when bonding is performed by using a bonding sheet.

[0010] However, air bubbles may exist in the solder layer disposed between the substrate and the heat sink, which may reduce the heat transfer and bonding performance between the substrate and the heat sink.

[0011] Accordingly, a structure capable of improving both the heat transfer performance and the bonding performance between the substrate and the heat sink is required. Summary of the Invention [Problem to be solved by the invention]

[0012] The technical problem that the present invention aims to achieve is to provide a thermoelectric module in which the heat transfer performance and the bonding performance between the substrate and the heat sink are both improved. [Means for solving the problem]

[0013] A thermoelectric module according to an embodiment of the present invention includes a thermoelectric element including a first substrate, a first electrode disposed on the first substrate, a semiconductor structure disposed on the first electrode, a second electrode disposed on the semiconductor structure, and a second substrate disposed on the second electrode, a heat sink disposed on the second substrate, and an adhesive layer for bonding the second substrate and the heat sink, the heat sink having a shape in which a predetermined pattern is regularly repeated and connected, each pattern including a first surface disposed to face the second substrate, a second surface extending upward from one end of the first surface, a third surface extending from the second surface to face the second substrate, and a fourth surface extending upward from another end opposite to the one end of the first surface and connected to the third surface of an adjacent pattern, the distance between the third surface and the second substrate being greater than the distance between the first surface and the second substrate, and the adhesive layer being disposed between the second substrate and the first surface.

[0014] The second substrate may have a plurality of regularly repeated grooves formed therein, and the adhesive layer and the first surface may be disposed within each groove.

[0015] The plurality of grooves may include a first groove and a second groove arranged adjacent to each other, one wall surface of the first groove and one wall surface of the second groove may be connected to each other through a connecting surface arranged to face the third surface, and the adhesive layer may be further arranged on at least a portion of the boundary between the wall surface of each groove and the connecting surface.

[0016] The adhesive layer may be absent from at least a portion of the connecting surface corresponding to a midpoint of the width of the third surface.

[0017] The first surface may have a plurality of holes formed therein. The adhesive layer may protrude above the first surface through at least some of the holes.

[0018] At least one slit may be formed along at least one of a boundary between the first surface and the second surface and a boundary between the first surface and the fourth surface, and the adhesive layer may protrude above the first surface through the at least one slit.

[0019] The third surface may have a width greater than a width of the first surface. Each of the patterns may further include a fifth surface between the first surface and the second surface, connecting the first surface and the second surface, and a size of an interior angle formed between the first surface and the fifth surface may be larger than a size of an interior angle formed between the second surface and the third surface.

[0020] The adhesive layer may be in direct contact with at least a portion of the fifth surface, and a thickness of the adhesive layer in direct contact with the fifth surface may be greater than a thickness of the adhesive layer in direct contact with the first surface.

[0021] A thermoelectric module according to another embodiment of the present invention includes a first substrate, a first insulating layer disposed on the first substrate, a plurality of first electrodes disposed on the first insulating layer, a plurality of thermoelectric legs disposed on the plurality of first electrodes, a plurality of second electrodes disposed on the plurality of thermoelectric legs, a second insulating layer disposed on the plurality of second electrodes, a second substrate disposed on the second insulating layer, an adhesive layer disposed on the second substrate, and a heat sink disposed on the adhesive layer, the heat sink having a shape in which a predetermined pattern is regularly repeated and connected, and each pattern is The pattern includes a first surface facing the second substrate and disposed so as to be in direct contact with the adhesive layer, a second surface extending upward from one end of the first surface, a third surface extending from the second surface so as to face the second substrate, and a fourth surface extending upward from another end opposite to the one end of the first surface and connected to the third surface of an adjacent pattern, the distance between the third surface and the second substrate being greater than the distance between the first surface and the second substrate, the second substrate having predetermined grooves formed therein that are regularly repeated, and the adhesive layer and the first surface being disposed within the grooves.

[0022] Each groove includes a bottom surface and wall surfaces extending upward from both side surfaces of the bottom surface, and the bottom surface, the adhesive layer and the first surface may be laminated in order.

[0023] The sum of the distances between both wall surfaces of each groove and each pattern housed in each groove may be 0.2 to 1 mm.

[0024] A first groove and a second groove are formed on the second substrate, one wall surface of the first groove and one wall surface of the second groove are connected to each other through a connecting surface, the connecting surface is parallel to the third surface, and the adhesive layer may be further disposed on at least a portion of the boundary between the wall surface of each groove and the connecting surface.

[0025] The adhesive layer may be absent from at least a portion of the connecting surface corresponding to a midpoint of the width of the third surface.

[0026] The distance between the connecting surface and the third surface may be 0.8 times or more and less than 1 time the perpendicular distance between the first surface and the third surface.

[0027] At least one notch may further be formed along the bottom surface and the boundary between the wall surfaces of each of the grooves.

[0028] The adhesive layer may further be disposed within the at least one notch.

[0029] At least one notch may be further formed in at least one of the two wall surfaces of each of the grooves in a direction perpendicular to the bottom surface, and the adhesive layer may be further disposed in the at least one notch.

[0030] A thermoelectric module according to yet another embodiment of the present invention includes a first substrate, a first insulating layer disposed on the first substrate, a plurality of first electrodes disposed on the first insulating layer, a plurality of thermoelectric legs disposed on the plurality of first electrodes, a plurality of second electrodes disposed on the plurality of thermoelectric legs, a second insulating layer disposed on the plurality of second electrodes, a second substrate disposed on the second insulating layer, an adhesive layer disposed on the second substrate, and a heat sink disposed on the adhesive layer, the heat sink having a shape in which predetermined patterns are regularly repeated and connected, each pattern including a first surface facing the second substrate and disposed to be in direct contact with the adhesive layer, a second surface extending upward from one end of the first surface, a third surface extending from the second surface to face the second substrate, and a fourth surface extending upward from another end opposite to the one end of the first surface and connected to the third surface of an adjacent pattern, a distance between the third surface and the second substrate being greater than a distance between the first surface and the second substrate, and a plurality of holes being disposed in the first surface.

[0031] The adhesive layer may be disposed on the first surface and protrude through at least some of the holes.

[0032] The area of ​​the plurality of holes formed in the first surface may be 10 to 30% of the area of ​​the first surface.

[0033] The diameter of at least one of the plurality of holes may be 25 to 75% of the distance between the fourth surface and the second surface of each pattern.

[0034] At least one of the plurality of holes may have the same diameter at a lowest point and a highest point of the first surface.

[0035] At least one of the plurality of holes may have a different diameter at a lowest point and a highest point of the first surface.

[0036] A diameter of the at least one hole at a highest point of the first surface may be greater than a diameter of the at least one hole at a lowest point of the first surface.

[0037] The diameter of the at least one hole at its highest point on the first surface may be 75-100% of the distance between the fourth surface and the second surface of each pattern.

[0038] At least one slit may be formed along a boundary between the first surface and the second surface.

[0039] The adhesive layer may be disposed on the first surface and the second surface, protruding through at least a portion of the at least one slit.

[0040] The adhesive layer may not be disposed on at least a portion of the first substrate corresponding to a midpoint of the width of the third surface.

[0041] A thermoelectric module according to yet another embodiment of the present invention includes a first substrate, a first insulating layer disposed on the first substrate, a plurality of first electrodes disposed on the first insulating layer, a plurality of thermoelectric legs disposed on the plurality of first electrodes, a plurality of second electrodes disposed on the plurality of thermoelectric legs, a second insulating layer disposed on the plurality of second electrodes, a second substrate disposed on the second insulating layer, an adhesive layer disposed on the second substrate, and a heat sink disposed on the adhesive layer, the heat sink having a shape in which predetermined patterns are regularly repeated and connected, each pattern including a first surface facing the second substrate and disposed so as to be in direct contact with the adhesive layer, a second surface extending upward from one end of the first surface, a third surface extending from the second surface to face the second substrate, and a fourth surface extending upward from another end opposite to the one end of the first surface and connected to the third surface of an adjacent pattern, the distance between the third surface and the second substrate being greater than the distance between the first surface and the second substrate, and the width of the third surface being greater than the width of the first surface.

[0042] The optical waveguide may further include at least one of a fifth surface connecting the first surface and the second surface between the first surface and the second surface and a sixth surface connecting the first surface and the fourth surface between the first surface and the fourth surface, and an interior angle formed by the first surface and the fifth surface may be different from an interior angle formed by the second surface and the third surface at a boundary between the second surface and the third surface.

[0043] An interior angle between the first surface and the fifth surface may be greater than an interior angle between the second surface and the third surface at a boundary between the second surface and the third surface.

[0044] An interior angle between the fifth surface and the second surface may be greater than an interior angle between the second surface and the third surface at a boundary between the second surface and the third surface.

[0045] The second surface and the fourth surface may be parallel to each other. The interior angle between the first surface and the fifth surface and the interior angle between the fifth surface and the second surface may be arranged to form obtuse angles.

[0046] The adhesive layer can be in direct contact with at least a portion of at least one of the fifth side and the sixth side.

[0047] A maximum height of an adhesive layer in direct contact with at least a portion of at least one of the fifth surface and the sixth surface may be greater than a maximum height of an adhesive layer in direct contact with the first surface.

[0048] The adhesive layer may not be disposed on at least a portion of the second substrate corresponding to a midpoint of the width of the third surface.

[0049] The distance between the second side and the fourth side of each pattern may be greater than the distance between the fifth side and the sixth side of each pattern, and the distance between the second side of each pattern and the fourth side of another adjacent pattern may be less than the distance between the fifth side of each pattern and the sixth side of another adjacent pattern.

[0050] The width of the first surface of each pattern may be 0.2 to 0.4 times the distance from the second surface to the fourth surface of each pattern.

[0051] The maximum height from the first surface to the fifth surface may be 1.5 to 3 times the thickness of the adhesive layer disposed under the first surface. Effect of the Invention

[0052] According to the embodiment of the present invention, a thermoelectric module having excellent performance and high reliability can be obtained. In particular, according to the embodiment of the present invention, a thermoelectric module having high durability can be obtained by improving not only the heat transfer performance but also the bonding performance between the substrate and the heat sink.

[0053] The thermoelectric device according to the embodiment of the present invention can be applied not only to small applications but also to large applications such as vehicles, ships, steelworks, and incinerators. [Brief description of the drawings]

[0054] [Figure 1] FIG. 2 is a cross-sectional view of a thermoelectric element. [Diagram 2] FIG. 2 is a perspective view of a thermoelectric element. [Diagram 3] FIG. 2 is a cross-sectional view of a thermoelectric module including a heat sink. [Figure 4] 1 shows an example of a bond between a substrate of a thermoelectric element and a heat sink. [Diagram 5] 1 is a cross-sectional view of a thermoelectric module according to an embodiment of the present invention. [Figure 6] 6 is a perspective view of a heat sink included in the thermoelectric module according to the embodiment of FIG. 5. [Figure 7a] 6 is an enlarged view of a partial cross-sectional view of the thermoelectric module according to the embodiment of FIG. 5. [Figure 7b] 6 is an enlarged view of a partial cross-sectional view of the thermoelectric module according to the embodiment of FIG. 5. [Figure 8] 1 is a graph showing a differential pressure ratio versus area of ​​an air passage of a heat sink. [Figure 9]11 is a cross-sectional view of a portion of a thermoelectric module according to another embodiment of the present invention. [Figure 10] 10 is a top view of a heat sink included in the thermoelectric module according to the embodiment of FIG. 9. [Figure 11] 10 is a perspective view of a heat sink included in the thermoelectric module according to the embodiment of FIG. 9. [Figure 12] 10 is a specific example of a portion of a heat sink included in the thermoelectric module according to the embodiment of FIG. 9. [Figure 13] 11 is a cross-sectional view of a portion of a thermoelectric module according to still another embodiment of the present invention. [Figure 14] 14 is a top view of a heat sink included in the thermoelectric module according to the embodiment of FIG. 13. FIG. [Figure 15] 14 is a perspective view of a heat sink included in the thermoelectric module according to the embodiment of FIG. 13. [Figure 16] 11 is a cross-sectional view of a portion of a thermoelectric module according to still another embodiment of the present invention. [Figure 17] 11 is a cross-sectional view of a portion of a thermoelectric module according to still another embodiment of the present invention. [Figure 18] 11 is a cross-sectional view of a portion of a thermoelectric module according to still another embodiment of the present invention. [Figure 19] 11 is a cross-sectional view of a portion of a thermoelectric module according to still another embodiment of the present invention. [Figure 20] 11 is a cross-sectional view of a portion of a thermoelectric module according to still another embodiment of the present invention. [Figure 21] 11 is a cross-sectional view of a portion of a thermoelectric module according to still another embodiment of the present invention. [Figure 22] 11 is a cross-sectional view of a portion of a thermoelectric module according to still another embodiment of the present invention. [Figure 23] 1 is a perspective view of an example of a heat conversion device to which a thermoelectric module according to an embodiment of the present invention is applied; [Figure 24] FIG. 24 is an exploded perspective view of the heat exchange device of FIG. 23. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0055] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0056] 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.

[0057] Furthermore, terms (including technical and scientific terms) used in the embodiments of the present invention may be interpreted in a manner that is commonly understood by a person having ordinary skill in the art to which the present invention belongs, unless otherwise clearly defined and described, and commonly used terms, such as terms defined in a dictionary, may be interpreted in light of the contextual meaning of the relevant art.

[0058] Furthermore, the terms used in the embodiments of the present invention are intended to describe the embodiments and are not intended to limit the present invention.

[0059] In this specification, the singular can include the plural unless otherwise specified in the context, and when it is stated that "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.

[0060] In addition, terms such as first, second, A, B, (a), (b), etc. may be used in describing components of embodiments of the present invention.

[0061] Such terms are merely used to distinguish a component from other components, and are not intended to limit the nature, order, or sequence of the components.

[0062] Furthermore, when a component is described as being "coupled," "coupled," or "connected" to another component, it includes not only cases where the component is directly coupled, coupled, or connected to the other component, but also cases where the component is "coupled," "coupled," or "connected" by yet another component between the component and the other component.

[0063] In addition, when described as being formed or disposed "above or below" each component, "above" or "below" includes not only the case where two components are in direct contact with each other, but also the case where one or more other components are formed or disposed between the two components. In addition, when described as "above or below," it can include not only the upper direction but also the lower direction based on one component.

[0064] 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 cross-sectional view of a thermoelectric module including a heat sink, and Figure 4 shows an example of the bond between the substrate of the thermoelectric element and the heat sink.

[0065] 1-2, the thermoelectric element 100 includes a lower substrate 110 , a lower electrode 120 , a P-type thermoelectric leg 130 , an N-type thermoelectric leg 140 , an upper electrode 150 and an upper substrate 160 .

[0066] 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. Accordingly, the plurality of P-type thermoelectric legs 130 and the plurality of N-type thermoelectric legs 140 are electrically connected by the lower electrode 120 and the upper electrode 150. A pair of the P-type thermoelectric legs 130 and the N-type thermoelectric legs 140 disposed and electrically connected between the lower electrode 120 and the upper electrode 150 may form a unit cell.

[0067] For example, when a voltage is applied to the lower electrode 120 and the upper electrode 150 through the lead wires 181, 182, the substrate in which a 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 a 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 to 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.

[0068] 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 raw 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 with respect to a total weight of 100 wt%, and may contain at least one of nickel (Ni), aluminum (Al), copper (Cu), silver (Ag), lead (Pb), boron (B), gallium (Ga), and indium (In) at 0.001 to 1 wt%. The N-type thermoelectric leg 140 may be a bismuth telluride (Bi-Te)-based 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 with respect to a total weight of 100 wt%, and may contain at least one of nickel (Ni), aluminum (Al), copper (Cu), silver (Ag), lead (Pb), boron (B), gallium (Ga), and indium (In) with a weight of 0.001 to 1 wt%.

[0069] The P-type thermoelectric leg 130 and the N-type thermoelectric leg 140 may be formed in a bulk type or a laminate type. In general, the bulk type P-type thermoelectric leg 130 or the bulk type N-type thermoelectric leg 140 may be obtained by heat treating a thermoelectric material to manufacture an ingot, crushing and sieving the ingot to obtain powder for the thermoelectric legs, sintering the powder, and cutting the sintered body. In this case, the P-type thermoelectric leg 130 and the N-type thermoelectric leg 140 may be polycrystalline thermoelectric legs. For the polycrystalline thermoelectric legs, the powder for the thermoelectric legs may be compressed at 100 MPa to 200 MPa when sintering. For example, when sintering the P-type thermoelectric leg 130, the powder for the thermoelectric legs may be sintered at 100 to 150 MPa, preferably 110 to 140 MPa, and more preferably 120 to 130 MPa. When sintering the N-type thermoelectric leg 140, the powder for the thermoelectric leg can be sintered at 150 to 200 MPa, preferably 160 to 195 MPa, and more preferably 170 to 190 MPa. In this manner, when the P-type thermoelectric leg 130 and the N-type thermoelectric leg 140 are polycrystalline thermoelectric legs, the strength of the P-type thermoelectric leg 130 and the N-type thermoelectric leg 140 can be increased. The stacked P-type thermoelectric leg 130 or the stacked N-type thermoelectric leg 140 can be obtained through a process of forming unit members by applying a paste containing a thermoelectric material onto a sheet-like substrate, and then stacking and cutting the unit members.

[0070] In this case, the pair of P-type thermoelectric legs 130 and N-type thermoelectric legs 140 may have the same shape and volume or may have different shapes and volumes. For example, since the electrical conduction characteristics of the P-type thermoelectric legs 130 and the N-type thermoelectric legs 140 are different, 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.

[0071] 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.

[0072] 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 a plurality of structures in which a semiconductor material is applied to a sheet-like substrate, and then cutting the laminated structures. As a result, material loss can be prevented and electrical conductivity characteristics can be improved. Each structure may further include a conductive layer having an opening pattern, thereby increasing the adhesive strength between the structures, decreasing thermal conductivity, and increasing electrical conductivity.

[0073] Alternatively, the P-type thermoelectric leg 130 or the N-type thermoelectric leg 140 may be formed to have different cross-sectional areas within one thermoelectric leg. For example, the cross-sectional area of ​​both ends arranged toward the electrodes within one thermoelectric leg may be formed to be larger than the cross-sectional area between the two ends. This can increase the temperature difference between the two ends, thereby increasing the thermoelectric efficiency.

[0074] The performance of the 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 follows:

[0075]

number

[0076] 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 temperature and k is thermal conductivity [W / mK]. k can be expressed as a·cp·ρ, and a is thermal diffusivity [cm 2 / S], cp is the specific heat [J / gK], and ρ is the density [g / cm 3 ].

[0077] To obtain the thermoelectric figure of merit of a thermoelectric element, a Z meter is used to measure the Z value (V / K), and the measured Z value is used to calculate the thermoelectric figure of merit ZT.

[0078] 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 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 function as an electrode may be deteriorated and the electrical conductivity may be reduced, and if it exceeds 0.3 mm, the forward efficiency may be reduced due to an increase in resistance.

[0079] The lower substrate 110 and the upper substrate 160 facing each other may be metal substrates, and may have a thickness of 0.1 mm to 1.5 mm. If the thickness of the metal substrate is less than 0.1 mm or exceeds 1.5 mm, the reliability of the thermoelectric element may be reduced due to excessively high heat dissipation characteristics or thermal conductivity. However, the thickness of the metal substrate described here is merely an example, and may vary depending on the size of the thermoelectric element 100 and the application to which it is applied. The metal substrate may be, for example, an aluminum, aluminum alloy, copper, copper alloy, or aluminum-copper alloy substrate, but is not limited thereto, and may be a substrate made of a metal having high thermal conductivity. In addition, when the lower substrate 110 and the 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.

[0080] At this time, the insulating layer 170 may include a resin composition and an inorganic filler. The resin composition may be a resin layer including at least one of an epoxy resin composition and a silicone resin composition, and the inorganic filler may include at least one of an oxide and a nitride. Accordingly, the insulating layer 170 may improve insulation, bonding strength, and thermal conductivity. Here, insulation may refer to insulation between adjacent layers as well as voltage resistance characteristics that prevent dielectric breakdown under high voltage.

[0081] Here, the inorganic filler may be contained in an amount of 68 to 88 vol% of the resin layer. If the inorganic filler is contained in an amount of less than 68 vol%, the thermal conductivity effect may be low, and if the inorganic filler is contained in an amount of more than 88 vol%, the resin layer may easily break.

[0082] In addition, when the resin composition includes an epoxy resin, the epoxy resin may include an epoxy compound and a curing agent. In this case, the epoxy compound may be included in a volume ratio of 10 to 10 of the curing agent. Here, the epoxy compound may include at least one of a crystalline epoxy compound, a non-crystalline epoxy compound, and a silicon epoxy compound. In the case where the resin composition includes a silicon resin, the silicon resin may include PDMS (polydimethylsiloxane).

[0083] The inorganic filler may include at least one of oxides and nitrides having heat dissipation or insulation properties, and the nitride may be included in the inorganic filler at 55 to 95 wt%, more preferably 60 to 80 wt%. When the nitride is included in such a numerical range, the thermal conductivity and bonding strength can be increased. Here, the nitride may include at least one of boron nitride and aluminum nitride, and the oxide may include at least one of aluminum oxide, titanium oxide, and zinc oxide.

[0084] When the nitride includes boron nitride, the boron nitride may be applied in the form of aggregates, in which case the particle size D50 of the boron nitride aggregates may be 250 to 350 μm, and the particle size D50 of the aluminum oxide may be 10 to 30 μm. When the particle size D50 of the boron nitride aggregates and the particle size D50 of the aluminum oxide satisfy these numerical ranges, the boron nitride aggregates and the aluminum oxide may be uniformly dispersed in the resin layer, and therefore the resin layer may have uniform heat conduction effect and adhesive performance throughout.

[0085] Although not shown, at least one of the insulating layers 170 disposed between the lower substrate 110 and the lower electrode 120 and between the upper substrate 160 and the upper electrode 150 may be composed of a plurality of layers. In this case, each of the plurality of layers may be formed containing the same or different resin compositions or inorganic fillers, and each layer may have a different thickness. Accordingly, the insulating layer 170 may further improve at least one of the properties of insulation, bonding strength, and thermal conductivity.

[0086] Alternatively, the lower substrate 110 and the upper substrate 160 facing each other may be insulating substrates. The insulating substrate may be a ceramic substrate having thermal conductivity and insulating properties or a substrate made of polymer resin. The ceramic substrate may be, for example, an aluminum oxide substrate or an aluminum nitride substrate.

[0087] Alternatively, one of the lower substrate 110 and the upper substrate 160 facing each other may be a metal substrate and the other may be an insulating substrate.

[0088] The lower substrate 110 and the upper substrate 160 may be formed to have different sizes. Preferably, the volume, thickness, or area of ​​the lower substrate 110 may be formed to be larger than the volume, thickness, or area of ​​the upper substrate 160, and the lower substrate 110 may be selectively disposed in a high temperature region or a low temperature region. For example, when it is necessary to optimize the heat transfer efficiency through a relative improvement in heat dissipation performance, the lower substrate 110 may be disposed in a high temperature region, and conversely, when it is necessary to optimize the heat transfer efficiency through a relative improvement in heat absorption performance, the lower substrate 110 may be disposed in a low temperature region. As another example, when a sealing member for protecting the thermoelectric module from the external environment is disposed on the lower substrate 110, and when a separate joining or fastening region is formed on the lower substrate 110 for coupling with the low temperature region or the high temperature region, at least one of the volume, thickness, or area may be larger than that of the upper substrate 160. In this case, the area of ​​the lower substrate 110 may be formed in a range of 1.2 to 5 times the area of ​​the upper substrate 160. If the area of ​​the lower substrate 110 is less than 1.2 times that of the upper substrate 160, the effect on improving heat transfer efficiency is not significant, and if it exceeds 5 times, the heat transfer efficiency may decrease significantly and it may be difficult to maintain the basic shape of the thermoelectric module.

[0089] 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. Accordingly, the heat dissipation performance of the thermoelectric device may be improved. When the concave-convex pattern is formed on the surface in contact with the P-type thermoelectric leg 130 or the N-type thermoelectric leg 140, the bonding characteristics between the thermoelectric legs and the substrate may be improved. The thermoelectric device 100 includes the lower substrate 110, the lower electrode 120, the P-type thermoelectric leg 130, the N-type thermoelectric leg 140, the upper electrode 150, and the upper substrate 160.

[0090] Although not shown, a sealing member may be further disposed between the lower substrate 110 and the upper substrate 160. The sealing member may be disposed on the sides of the lower electrode 120, the P-type thermoelectric legs 130, the N-type thermoelectric legs 140, and the upper electrode 150 between the lower substrate 110 and the upper substrate 160. Accordingly, the lower electrode 120, the P-type thermoelectric legs 130, the N-type thermoelectric legs 140, and the upper electrode 150 may be sealed from external moisture, heat, contamination, and the like. Here, the sealing member may include a sealing case disposed at a predetermined distance from the outermost peripheries of the plurality of lower electrodes 120, the outermost peripheries of the plurality of P-type thermoelectric legs 130 and the plurality of N-type thermoelectric legs 140, and the outermost peripheries of the plurality of upper electrodes 150, a sealing material disposed between the sealing case and the lower substrate 110, and a sealing material disposed between the sealing case and the upper substrate 160. In this way, the sealing case can be in contact with the lower substrate 110 and the upper substrate 160 through the sealing material. Accordingly, when the sealing case is in direct contact with the lower substrate 110 and the upper substrate 160, heat conduction occurs through the sealing case, and as a result, the problem of a decrease in temperature difference between the lower substrate 110 and the upper substrate 160 can be prevented. Here, the sealing material can include at least one of epoxy resin and silicone resin, or can include a tape having at least one of epoxy resin and silicone resin applied on both sides. The sealant serves to hermetically seal between the sealing case and the lower substrate 110 and between the sealing case and the upper substrate 160, and can 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, and can be used together with a finishing material, a finishing layer, a waterproof material, a waterproof layer, etc. However, the above description of the sealing member is merely an example, and the sealing member can be modified into various forms. Although not shown, an insulating material may further be included surrounding the sealing member, or the sealing member may include an insulating component.

[0091] Meanwhile, the P-type thermoelectric leg 130 and the N-type thermoelectric leg 140 may have the structure shown in Fig. 1(a) or 1(b). Referring to Fig. 1(a), the thermoelectric legs 130, 140 may include thermoelectric material layers 132, 142, first plating layers 134-1, 144-1 stacked on one surface of the thermoelectric material layers 132, 142, and second plating layers 134-2, 144-2 stacked on the other surface disposed opposite to the one surface of the thermoelectric material layers 132, 142. Alternatively, referring to FIG. 1( b ), the thermoelectric legs 130, 140 may include thermoelectric material layers 132, 142, first plating layers 134-1, 144-1 stacked on one side of the thermoelectric material layers 132, 142, second plating layers 134-2, 144-2 stacked on the other side opposite the one side of the thermoelectric material layers 132, 142, and first buffer layers 136-1, 146-1 and second buffer layers 136-2, 146-2 respectively positioned between the thermoelectric material layers 132, 142 and the first plating layers 134-1, 144-1 and between the thermoelectric material layers 132, 142 and the second plating layers 134-2, 144-2, respectively. Alternatively, the thermoelectric legs 130, 140 may further include a metal layer laminated between the first plating layers 134-1, 144-1 and the second plating layers 134-2, 144-2, respectively, and the lower substrate 110 and the upper substrate 160, respectively.

[0092] Here, the thermoelectric material layers 132, 142 may include semiconductor materials such as bismuth (Bi) and tellurium (Te). The thermoelectric material layers 132, 142 may have the same material or shape as the P-type thermoelectric leg 130 or the N-type thermoelectric leg 140 described above. When the thermoelectric material layers 132, 142 are polycrystalline, the adhesive strength between the thermoelectric material layers 132, 142, the first buffer layers 136-1, 146-1, and the first plating layers 134-1, 144-1, and the adhesive strength between the thermoelectric material layers 132, 142, the second buffer layers 136-2, 146-2, and the second plating layers 134-2, 144-2 may be increased. As a result, even if the thermoelectric element 100 is applied to an application in which vibration occurs, such as a vehicle, the first plating layers 134-1, 144-1 and the second plating layers 134-2, 144-2 can be prevented from detaching from the P-type thermoelectric leg 130 or the N-type thermoelectric leg 140 and carbonizing, thereby improving the durability and reliability of the thermoelectric element 100.

[0093] And, the metal layer may be selected from copper (Cu), copper alloy, aluminum (Al) and aluminum alloy, and may have a thickness of 0.1-0.5 mm, preferably 0.2-0.3 mm.

[0094] Next, the first plating layers 134-1, 144-1 and the second plating layers 134-2, 144-2 may each contain at least one of Ni, Sn, Ti, Fe, Sb, Cr, and Mo, and may have a thickness of 1 to 20 μm, preferably 1 to 10 μm. The first plating layers 134-1, 144-1 and the second plating layers 134-2, 144-2 prevent a reaction between the metal layer and the semiconductor material Bi or Te in the thermoelectric material layers 132, 142, and therefore not only can the performance of the thermoelectric element be prevented from being deteriorated, but also the metal layer can be prevented from being oxidized.

[0095] At this time, the first buffer layers 136-1, 146-1 and the second buffer layers 136-2, 146-2 may be disposed between the thermoelectric material layers 132, 142 and the first plating layers 134-1, 144-1 and between the thermoelectric material layers 132, 142 and the second plating layers 134-2, 144-2. At this time, the first buffer layers 136-1, 146-1 and the second buffer layers 136-2, 146-2 may contain Te. For example, the first buffer layers 136-1, 146-1 and the second buffer layers 136-2, 146-2 may contain at least one of Ni-Te, Sn-Te, Ti-Te, Fe-Te, Sb-Te, Cr-Te, and Mo-Te. According to the embodiment of the present invention, when the first buffer layers 136-1, 146-1 and the second buffer layers 136-2, 146-2 containing Te are disposed between the thermoelectric material layers 132, 142 and the first plating layers 134-1, 144-1 and the second plating layers 134-2, 144-2, it is possible to prevent the diffusion of Te in the thermoelectric material layers 132, 142 into the first plating layers 134-1, 144-1 and the second plating layers 134-2, 144-2. As a result, it is possible to prevent the problem of an increase in electrical resistance in the thermoelectric material layers due to a Bi-rich region.

[0096] In the above, the terms lower substrate 110, lower electrode 120, upper electrode 150, and upper substrate 160 are used, but these are merely arbitrarily referred to as upper and lower for ease of understanding and convenience of description, and the positions may be reversed so that the lower substrate 110 and the lower electrode 120 are disposed at the upper portion, and the upper electrode 150 and the upper substrate 160 are disposed at the lower portion. In this specification, the lower substrate 110 may be used interchangeably with the first substrate 110, the lower electrode 120 may be used interchangeably with the first electrode 120, the upper electrode 150 may be used interchangeably with the second electrode 150, and the upper substrate 160 may be used interchangeably with the second substrate 160.

[0097] 3, the heat sink 200 is disposed on an upper substrate, i.e., a second substrate 160. At this time, the heat sink 200 may be embodied to form an air passage using a flat substrate so as to be in surface contact with air passing through the heat sink 200. That is, the heat sink 200 may have a structure in which the substrate is folded so as to form a repeating pattern having a predetermined pitch P and height H, i.e., a folded structure.

[0098] Meanwhile, in order to bond the second substrate 160 and the heat sink 200, an adhesive layer 300 consisting of a layer containing at least one of a polymer resin and a metal is disposed between the second substrate 160 and the heat sink 200, and the second substrate 160 and the heat sink 200 can be bonded through a bonding process in which pressure or heat is applied, or pressure and heat are applied simultaneously.

[0099] 4(a) and 4(b), the adhesive layer 300 disposed between the second substrate 160 and the heat sink 200 may have many bubbles remaining even after the bonding process. The adhesive layer 300 is a mixture of a polymer resin and a metal material, and may be in the form of a paste before hardening. The polymer resin may impart fluidity to the adhesive layer 300 to facilitate application onto the second substrate 160, and the metal material may include at least one of tin (Sn), silver (Ag), copper (Cu), and aluminum (Al) to provide bonding strength and heat transfer properties between the second substrate 160 and the heat sink 200. Many bubbles may be contained in the polymer resin, and the heat transfer path between the second substrate 160 and the heat sink 200 may be reduced due to the bubbles, resulting in reduced heat transfer performance. Also, the bonding performance between the second substrate 160 and the heat sink 200 may be reduced due to the bubbles.

[0100] The amount of air bubbles in the adhesive layer 300 disposed between the second substrate 160 and the heat sink 200 may vary depending on the bonding area between the second substrate 160 and the heat sink 200, the thickness, or the material of the adhesive layer 300. The larger the bonding area or thickness between the second substrate 160 and the heat sink 200, or the higher the content of the polymer resin in the adhesive layer 300, the more difficult it is for the air bubbles generated in the adhesive layer 300 to escape to the outside, so that a large number of air bubbles may remain even after the bonding process. If the pitch of the heat sink 200 is reduced to reduce the bonding area between the second substrate 160 and the heat sink 200, the amount of air bubbles in the adhesive layer 300 may decrease, but in applications where high or low temperature air is forced to flow into the heat sink 200 area, the air resistance increases and the air pressure in the adjacent area increases. As a result, some of the stagnant air that cannot pass through the heat sink 200 area may flow back and adversely affect the surrounding system, and the air that passes through the heat sink 200 may not be able to flow at the appropriate rate. Therefore, in order to prevent a decrease in efficiency of the thermoelectric module or a thermoelectric system to which the thermoelectric module is applied, it is preferable to minimize the pressure difference between the air before and after passing through the heat sink 200 area.

[0101] Accordingly, the present invention provides a heat sink or substrate structure with improved heat transfer performance, bonding performance, and power generation performance.

[0102] Fig. 5 is a cross-sectional view of a thermoelectric module according to an embodiment of the present invention, Fig. 6 is a perspective view of a heat sink included in the thermoelectric module according to the embodiment of Fig. 5, and Fig. 7 is an enlarged view of a part of the cross-sectional view of the thermoelectric module according to the embodiment of Fig. 5. Here, the details of the detailed structure of the thermoelectric element 100, i.e., the lower substrate 110, the lower electrode 120, the P-type thermoelectric leg 130, the N-type thermoelectric leg 140, the upper electrode 150, the upper substrate 160, and the insulating layer 170, may be the same as those described with reference to Figs. 1 and 2, and therefore, for convenience of description, a duplicated description will be omitted.

[0103] 5 to 7, an adhesive layer 300 is disposed on the second substrate 160, and a heat sink 200 is disposed on the adhesive layer 300. The second substrate 160 and the heat sink 200 may be bonded to each other by the adhesive layer 300. Here, the heat sink 200 is described as being disposed on the upper substrate 160, i.e., the second substrate 160, but this is for convenience of description and is not intended to be limiting. That is, the heat sink 200 having the same structure as that of the embodiment of the present invention may be disposed on the lower substrate 110, i.e., the first substrate 110, or may be disposed on both the first substrate 110 and the second substrate 160.

[0104] According to an embodiment of the present invention, the heat sink 200 may have a shape in which a predetermined pattern is regularly repeated and connected, that is, the heat sink 200 may include a first pattern X1, a second pattern X2, and a third pattern X3, and these patterns may be an integral flat plate that is sequentially connected.

[0105] According to an embodiment of the present invention, each pattern X1, X2, X3 includes a first surface 210, a second surface 220, a third surface 230 and a fourth surface 240 connected in sequence, and each of the first surface 210, the second surface 220, the third surface 230 and the fourth surface 240 may be multiple.

[0106] The first surface 210 faces the second substrate 160, but may be disposed so as to be in direct contact with the adhesive layer 300. The second surface 220 may extend upward from a first end of the first surface 210. The fourth surface 240 may extend upward from a second end opposite to the first end of the first surface 210. The third surface 230 faces the second substrate 160, but may extend from the second surface 220 so as to be spaced apart from the adhesive layer 300, and may extend from the fourth surface 240 of an adjacent pattern and be connected to each other. The first surface 210, the second surface 220, the third surface 230, and the fourth surface 240 may be an integral flat plate having a structure that is folded in sequence. The first surface 210 may be parallel to the second substrate 160, and the third surface 230 may be parallel to the second substrate 160. In this embodiment, the term "parallel" may be defined as an interior angle between the top surface of the second substrate 160, i.e., the surface that directly contacts the adhesive layer 300, and the first surface 210 or the third surface 230 being within 2°.

[0107] Here, the upper portion may refer to a direction away from the second substrate 160 on the second substrate 160, and the lower portion may refer to a direction toward the second substrate 160 on the second substrate 160. That is, the distance between the third surface 230 and the second substrate 160 may be greater than the distance between the first surface 210 and the second substrate 160.

[0108] The second surface 220 of the first pattern X1 is connected to the fourth surface 240 of the second pattern X2 adjacent to the first pattern X1 via the third surface 230 of the first pattern X1, and similarly, the second surface 220 of the second pattern X2 can be connected to the fourth surface 240 of the third pattern X3 adjacent to the second pattern X2 via the third surface 230 of the second pattern X2.

[0109] Meanwhile, according to an embodiment of the present invention, as shown in Fig. 7(a), the width W3 of the third surface 230 may be greater than the width W1 of the first surface 210. For this purpose, the fifth surface 250 connecting the first surface 210 and the second surface 220 between the first surface 210 and the second surface 220 and the sixth surface 260 connecting the first surface 210 and the fourth surface 240 between the first surface 210 and the fourth surface 240 may be further included or all of them may be included. The interior angle θ1 formed by the first surface 210 and the fifth surface 250 may be different from the interior angle θ2 formed by the second surface 220 and the third surface 230 at the boundary between the second surface 220 and the third surface 230. In addition, the interior angle θ3 between the fifth surface 250 and the second surface 220 may be different from the interior angle θ2 between the second surface 220 and the third surface 230 at the boundary between the second surface 220 and the third surface 230. For example, the interior angle θ1 between the first surface 210 and the fifth surface 250 at the boundary between the first surface 210 and the fifth surface 250 may be larger than the interior angle θ2 between the second surface 220 and the third surface 230 at the boundary between the second surface 220 and the third surface 230. In addition, the interior angle θ3 between the fifth surface 250 and the second surface 220 at the boundary between the fifth surface 250 and the second surface 220 may be larger than the interior angle θ2 between the second surface 220 and the third surface 230 at the boundary between the second surface 220 and the third surface 230. When a sixth surface 260 is further included between the first surface 210 and the fourth surface 240, connecting the first surface 210 and the fourth surface 240, the sixth surface 260 may be formed to have a shape that is approximately symmetrical to the fifth surface 250. Therefore, the interior angle θ4 that the sixth surface 260 makes with the first surface 210 or the interior angle θ5 that the sixth surface 260 makes with the fourth surface 240 may be applied in the same manner as the relationship between θ1 and θ3 described above. 7(a) and 7(b) mainly show an example in which a fifth surface 250 is disposed between the first surface 210 and the second surface 220, and a sixth surface 260 symmetrical to the fifth surface 250 is disposed between the first surface 210 and the fourth surface 240, but this is not limited to this example. As shown in FIG. 5(a) and FIG. 6(a), the fifth surface 250 may be disposed between the first surface 210 and the second surface 220, and the first surface 210 and the fourth surface 240 may be directly connected, or, although not shown, the sixth surface 260 may be disposed between the first surface 210 and the fourth surface 240, and the first surface 210 and the second surface 220 may be directly connected.

[0110] 7(a) and 7(b), it can be seen that the interior angle θ1 between the first surface 210 and the fifth surface 250 at the boundary between the first surface 210 and the second surface 220 exceeds 90° and is an obtuse angle, and the interior angle θ2 between the second surface 220 and the third surface 230 at the boundary between the second surface 220 and the third surface 230 is approximately a right angle. As a result, the contact area between the first surface 210 and the adhesive layer 300 can be narrowed, so that air bubbles in the adhesive layer 300 can be reduced. In addition, since the contact area between the first surface 210 and the adhesive layer 300 can be narrowed while maintaining the pattern pitch P of the pattern forming the heat sink 200, the pressure difference between the air before passing through the heat sink 200 area and after passing through the heat sink 200 area can be minimized.

[0111] More specifically, as shown in Fig. 7(a) and Fig. 7(b), the distance d1 between the second surface 220 of the first pattern X1 and the fourth surface 240 of the second pattern X2 may be smaller than the distance d2 between the fifth surface 250 of the first pattern X1 and the sixth surface 260 of the second pattern X2, and the distance d3 between the fourth surface 240 of the second pattern X2 and the second surface 220 of the second pattern X2 may be larger than the distance d4 between the fifth surface 250 of the second pattern X2 and the sixth surface 260 of the second pattern X2. As a result, the contact area between the first surface 210 and the adhesive layer 300 can be narrowed while maintaining the pattern pitch P of the patterns constituting the heat sink 200, and the area of ​​the flow path through which the air passes is not substantially reduced, so that the pressure difference between the air before passing through the heat sink 200 area and after passing through the heat sink 200 area can be minimized. At this time, the width W1 of the first surface 210 of each pattern may be 0.2 to 0.4 times the pitch of the pattern, for example, the distance from the fourth surface 240 of the first pattern X1 to the fourth surface 240 of the second pattern X2, and the maximum height of the fifth surface 250 or the sixth surface 260 from the first surface 210 may be 1.5 to 3 times the thickness of the adhesive layer 300 disposed under the first surface 210. For example, when the pattern pitch is 3.76 mm, the width W1 of the first surface 210 may be 0.75 to 1.5 mm, preferably 0.85 to 1.35 mm, and more preferably 0.95 to 1.2 mm, and when the thickness of the adhesive layer 300 is 1.5 mm, the maximum height of the fifth surface 250 or the sixth surface 260 from the first surface 210 may be 3 to 4.5 mm. This allows the area of ​​the first surface 210 that is bonded to the adhesive layer 300 to be minimized without reducing the pattern pitch, thereby minimizing the pressure difference of the air before and after passing through the heat sink 200 area.

[0112] Meanwhile, as shown in Fig. 7(a), the adhesive layer 300 is disposed under the first surface 210 so as to be in direct contact with the first surface 210, but as shown in Fig. 7(b), a part of the adhesive layer 300 may also be in direct contact with at least a part of the fifth surface 250 and the sixth surface 260. Accordingly, the maximum height h2 of the adhesive layer 300 in direct contact with at least a part of the fifth surface 250 and the sixth surface 260 may be higher than the maximum height h1 of the adhesive layer 300 in direct contact with the first surface 210. This may be formed by a process in which the adhesive layer 300 is applied on the second substrate 160, the first surface 210 is placed on the adhesive layer 300, and then the adhesive layer 300 leaks to the fifth surface 250 and the sixth surface 260 and hardens during the process of applying pressure. According to this, the adhesive layer 300 is disposed not only on the first surface 210 but also on the fifth surface 250 and the sixth surface 260, which not only increases the bonding strength between the second substrate 160 and the heat sink 200, but also makes it easier for air bubbles to escape to the outside of the adhesive layer 300 due to the maximum height h2 of the adhesive layer 300.

[0113] At this time, the adhesive layer 300 may be applied to the entire surface of the second substrate 160, but preferably, may be applied only to the region where the first surface 210 is disposed. Accordingly, the adhesive layer 300 may not be disposed on at least a portion of the second substrate 160 corresponding to the third surface 230. For example, the adhesive layer 300 may not be disposed on at least a portion of the second substrate 160 corresponding to the midpoint of the width of the third surface 230. In this way, the amount of material constituting the adhesive layer 300 can be minimized, and the separation space between the second substrate 160 and the third surface 230 is widened, so that air flow can be efficiently generated.

[0114] FIG. 8 is a graph showing air pressure difference versus area of ​​the air flow passage of the heat sink.

[0115] 8, it can be seen that the ratio of the air pressure difference increases as the ratio of the air area decreases, assuming that the air area is 1. Here, the air pressure difference can mean the difference between the pressure of the air before and after it passes through the heat sink. That is, as the pitch of the heat sink 200 decreases, the area of ​​the air flow path of the heat sink becomes smaller, and the pressure difference of the air before and after passing through the heat sink 200 area becomes larger, which can mean that as the area of ​​the air flow path of the heat sink becomes smaller, the air resistance and the air pressure in the surrounding area increase, and the air flow through the heat sink is restricted.

[0116] For example, when two heat sinks with the same area, height, and plate thickness are arranged in the same area, if the pitch of one of the two heat sinks is reduced to 1 / 2, the actual air area is reduced to about 0.9 times that of the other heat sink, and the ratio of the air pressure difference is about 1.1, which can be increased by more than about 10%.

[0117] Meanwhile, when the heat sink is designed according to the embodiment of the present invention, the contact area with the adhesive layer 300 can be minimized while the air area is not substantially reduced, so that a thermoelectric module can be obtained that improves the bonding performance between the substrate and the heat sink without degrading the thermoelectric performance.

[0118] Fig. 9 is a cross-sectional view of a portion of a thermoelectric module according to another embodiment of the present invention, Fig. 10 is a top view of a heat sink included in the thermoelectric module according to the embodiment of Fig. 9, Fig. 11 is a perspective view of the heat sink included in the thermoelectric module according to the embodiment of Fig. 9, and Fig. 12 is a specific example of a portion of the heat sink included in the thermoelectric module according to the embodiment of Fig. 9. Here, the detailed structure of the thermoelectric element 100, i.e., the lower substrate 110, the lower electrode 120, the P-type thermoelectric leg 130, the N-type thermoelectric leg 140, the upper electrode 150, and the insulating layer 170 are not separately illustrated, and the structures described in Figs. 1 and 2 can be applied in the same way, so that repeated description will be omitted for convenience of description.

[0119] 9 to 12, an adhesive layer 300 is disposed on the second substrate 160, and a heat sink 200 is disposed on the adhesive layer 300. The second substrate 160 and the heat sink 200 may be bonded to each other by the adhesive layer 300. Here, the heat sink 200 is described as being disposed on the upper substrate 160, i.e., the second substrate 160, but this is for convenience of description and is not intended to be limiting. That is, the heat sink 200 having the same structure as that of the embodiment of the present invention may be disposed on the lower substrate 110, i.e., the first substrate 110, or may be disposed on both the first substrate 110 and the second substrate 160.

[0120] According to an embodiment of the present invention, the heat sink 200 may have a shape in which a predetermined pattern is regularly repeated and connected, that is, the heat sink 200 may include a first pattern X1, a second pattern X2, and a third pattern X3, and these patterns may be an integral flat plate that is sequentially connected.

[0121] According to an embodiment of the present invention, each pattern X1, X2, X3 includes a first surface 210, a second surface 220, a third surface 230 and a fourth surface 240 connected in sequence, and each of the first surface 210, the second surface 220, the third surface 230 and the fourth surface 240 may be multiple.

[0122] The first surface 210 faces the second substrate 160, but may be disposed so as to be in direct contact with the adhesive layer 300. The second surface 220 may extend upward from a first end of the first surface 210. The fourth surface 240 may extend upward from a second end opposite to the first end of the first surface 210. The third surface 230 faces the second substrate 160, but may extend from the second surface 220 so as to be spaced apart from the adhesive layer 300, and may extend from the fourth surface 240 of an adjacent pattern and be connected to each other. The first surface 210, the second surface 220, the third surface 230, and the fourth surface 240 may be an integral flat plate having a structure that is folded in sequence. Also, the first surface 210 may be parallel to the second substrate 160, and the third surface 230 may be parallel to the second substrate 160. In this embodiment, the term "parallel" may be defined as an interior angle between the top surface of the second substrate 160, i.e., the surface that directly contacts the adhesive layer 300, and the first surface 210 or the third surface 230 being within 2°.

[0123] Here, the upper portion may refer to a direction away from the second substrate 160 on the second substrate 160, and the lower portion may refer to a direction toward the second substrate 160 on the second substrate 160. That is, the distance between the third surface 230 and the second substrate 160 may be greater than the distance between the first surface 210 and the second substrate 160.

[0124] The second surface 220 of the first pattern X1 is connected to the fourth surface 240 of the second pattern X2 adjacent to the first pattern X1 via the third surface 230 of the first pattern X1, and similarly, the second surface 220 of the second pattern X2 may be connected to the fourth surface 240 of the third pattern X3 adjacent to the second pattern X2 via the third surface 230 of the second pattern X2. At this time, the adhesive layer 300 may be applied to the entire surface of the second substrate 160, but preferably, may be applied only to the area where the first surface 210 is disposed. Accordingly, the adhesive layer 300 may not be disposed on at least a portion of the second substrate 160 corresponding to the third surface 230. For example, the adhesive layer 300 may not be disposed on at least a portion of the second substrate 160 corresponding to the middle point of the width of the third surface 230. This allows the amount of material forming the adhesive layer 300 to be minimized, and the space between the second substrate 160 and the third surface 230 to be widened, allowing air flow to occur efficiently.

[0125] Meanwhile, according to an embodiment of the present invention, the first surface 210 may have a plurality of holes 212 formed at a predetermined interval or at irregular intervals. In this case, the adhesive layer 300 may be disposed on the first surface 210 by protruding through at least some of the plurality of holes 212. This may be formed by applying the adhesive layer 300 on the second substrate 160, disposing the first surface 210 on the adhesive layer 300, and then applying pressure to the adhesive layer 300, whereby the adhesive layer 300 leaks through the holes 212 of the first surface 210 and hardens. In this case, the adhesive layer 300 is disposed not only on the lower surface of the first surface 210 but also on the upper surface of the first surface 210, so that not only the adhesive strength between the second substrate 160 and the heat sink 200 is increased, but also the adhesive layer 300 protruding on the first surface 210 may make it easier for air bubbles to escape from the adhesive layer 300. Here, the holes 212 may be processed using an etching method, a drilling method, or the like, but are not limited thereto.

[0126] At this time, the area of ​​the plurality of holes 212 formed in the first surface 210 may be 10 to 30% of the area of ​​the first surface 210. If the area of ​​the plurality of holes 212 is less than 10% of the area of ​​the first surface 210, it may be difficult for air bubbles in the adhesive layer 300 to escape, and if the area of ​​the plurality of holes 212 exceeds 30% of the area of ​​the first surface 210, the adhesive strength between the first surface 210 and the second substrate 160 may be reduced.

[0127] Alternatively, the diameter of at least one of the plurality of holes 212 may be 25 to 75% of the width W1 of the first surface 210, i.e., the distance between the fourth surface 240 of the first pattern X1 and the second surface 220 of the first pattern X1. If the diameter of the hole 212 is less than 25% of the distance between the fourth surface 240 of the first pattern X1 and the second surface 220 of the first pattern X1, it may be difficult for air bubbles in the adhesive layer 300 to escape, and if the diameter of the hole 212 exceeds 75% of the distance between the fourth surface 240 of the first pattern X1 and the second surface 220 of the first pattern X1, the bonding strength between the first surface 210 and the second substrate 160 may decrease or air resistance may increase.

[0128] Meanwhile, referring to Fig. 12, the shape of the hole may be modified in various ways. For example, referring to Fig. 12(a), the diameter of the hole 212 may be the same at the lowest point 210-L and the highest point 210-H of the first surface 210. Or, referring to Fig. 12(b), the diameter of the hole 212 may be different at the lowest point 210-L and the highest point 210-H of the first surface 210. For example, the diameter of the hole 212 at the highest point 210-H may be larger than the diameter of the hole 212 at the lowest point 210-L of the first surface 210. In this case, the diameter of the hole 212 at the highest point 210-H may be 75 to 100% of the width W1 of the first surface 210, that is, the distance between the fourth surface 240 of the first pattern X1 and the second surface 220 of the second pattern X2. In this manner, by forming the diameter of the hole 212 at the highest point 210-H to be larger than the diameter of the hole 212 at the lowest point 210-L of the first surface 210, the adhesive strength between the second substrate 160 and the heat sink 200 may not be reduced, and the number of paths through which the pores in the adhesive layer 300 can escape may be increased.

[0129] Fig. 13 is a cross-sectional view of a portion of a thermoelectric module according to another embodiment of the present invention, Fig. 14 is a top view of a heat sink included in the thermoelectric module according to the embodiment of Fig. 13, and Fig. 15 is a perspective view of the heat sink included in the thermoelectric module according to the embodiment of Fig. 13. Here, the detailed structure of the thermoelectric element 100, i.e., the lower substrate 110, the lower electrode 120, the P-type thermoelectric leg 130, the N-type thermoelectric leg 140, the upper electrode 150, and the insulating layer 170 are not separately illustrated, and the structures described in Figs. 1 and 2 can be applied in the same manner, so that for convenience of explanation, duplicated explanations will be omitted. Also, duplicated explanations will be omitted for the same contents among those described in Figs. 9 to 12.

[0130] 13 to 15, at least one slit 214 may be further formed along the boundary between the first surface 210 and the second surface 220 and the boundary between the first surface 210 and the fourth surface 240. According to this, the adhesive layer 300 may protrude through the slit 214 and be further disposed on the first surface 210 and the second surface 220, and may be further disposed on the first surface 210 and the fourth surface 240. This may be formed by a process in which the adhesive layer 300 is applied on the second substrate 160, the first surface 210 is disposed on the adhesive layer 300, and then the adhesive layer 300 leaks through the slit 214 and hardens during the process of applying pressure. According to this, the adhesive layer 300 is disposed not only on the underside of the first surface 210, but also on the upper surface of the first surface 210 and the second surface 220, which not only increases the bonding strength between the second substrate 160 and the heat sink 200, but also makes it easier for air bubbles to escape outside the adhesive layer 300 due to the adhesive layer 300 protruding above the first surface 210 and the second surface 220.

[0131] 16 to 18 are cross-sectional views of a portion of a thermoelectric module according to another embodiment of the present invention. Here, the detailed structure of the thermoelectric element 100, i.e., the lower substrate 110, the lower electrode 120, the P-type thermoelectric leg 130, the N-type thermoelectric leg 140, the upper electrode 150, and the insulating layer 170, are not separately illustrated, and the structure described in FIGS. 1 and 2 can be applied in the same manner, so that the redundant description will be omitted for convenience of description.

[0132] 16 to 18, an adhesive layer 300 is disposed on the second substrate 160, and a heat sink 200 is disposed on the adhesive layer 300. The second substrate 160 and the heat sink 200 may be bonded to each other by the adhesive layer 300. Here, the heat sink 200 is described as being disposed on the upper substrate 160, i.e., the second substrate 160, but this is for convenience of description and is not intended to be limiting. That is, the heat sink 200 having the same structure as that of the embodiment of the present invention may be disposed on the lower substrate 110, i.e., the first substrate 110, or may be disposed on both the first substrate 110 and the second substrate 160.

[0133] According to an embodiment of the present invention, the heat sink 200 may have a shape in which a predetermined pattern is regularly repeated and connected, that is, the heat sink 200 may include a first pattern X1 and a second pattern X2, and these patterns may be an integral flat plate that is sequentially connected.

[0134] According to an embodiment of the present invention, each pattern X1, X2, X3 includes a first surface 210, a second surface 220, a third surface 230 and a fourth surface 240 connected in sequence, and each of the first surface 210, the second surface 220, the third surface 230 and the fourth surface 240 may be multiple.

[0135] The first surface 210 faces the second substrate 160, but may be disposed so as to be in direct contact with the adhesive layer 300. The second surface 220 may extend upward from a first end of the first surface 210. The fourth surface 240 may extend upward from a second end opposite to the first end of the first surface 210. The third surface 230 faces the second substrate 160, but may extend from the second surface 220 so as to be spaced apart from the adhesive layer 300, and may extend from the fourth surface 240 of an adjacent pattern and be connected to each other. The first surface 210, the second surface 220, the third surface 230, and the fourth surface 240 may be an integral flat plate having a structure that is folded in sequence. Also, the first surface 210 may be parallel to the second substrate 160, and the third surface 230 may be parallel to the second substrate 160. In this embodiment, the term "parallel" may be defined as an interior angle between the top surface of the second substrate 160, i.e., the surface that directly contacts the adhesive layer 300, and the first surface 210 or the third surface 230 being within 2°.

[0136] Here, the upper portion may refer to a direction away from the second substrate 160 on the second substrate 160, and the lower portion may refer to a direction toward the second substrate 160 on the second substrate 160. That is, the distance between the third surface 230 and the second substrate 160 may be greater than the distance between the first surface 210 and the second substrate 160.

[0137] The second surface 220 of the first pattern X1 is connected to the fourth surface 240 of the second pattern X2 adjacent to the first pattern X1 via the third surface 230 of the first pattern X1, and similarly, the second surface 220 of the second pattern X2 can be connected to the fourth surface 240 of the third pattern X3 adjacent to the second pattern X2 via the third surface 230 of the second pattern X2.

[0138] At this time, the adhesive layer 300 may be applied to the entire surface of the second substrate 160, but preferably, the adhesive layer 300 may not be disposed on at least a portion of the second substrate 160 corresponding to the third surface 230. For example, the adhesive layer 300 may not be disposed on at least a portion of the second substrate 160 corresponding to a midpoint of the width of the third surface 230. In this way, the amount of material constituting the adhesive layer 300 can be minimized, and the separation space between the second substrate 160 and the third surface 230 is widened, so that air flow can be efficiently generated.

[0139] Meanwhile, according to an embodiment of the present invention, predetermined grooves 162 may be formed on the second substrate 160 in a regularly repeated pattern, and the adhesive layer 300 and the first surface 210 may be disposed in the grooves 162 .

[0140] At this time, each groove 162 includes a bottom surface 162-1 and wall surfaces 162-2, 162-3 extending upward from both side surfaces of the bottom surface 162-1, and an adhesive layer 300 and a first surface 210 can be sequentially laminated on the bottom surface 162-1.

[0141] At this time, a portion of the second surface 220 connected to the first surface 210 and a portion of the fourth surface 240 may be further disposed within the groove 162, and an adhesive layer 300 may be further disposed between both wall surfaces 162-2, 162-3 of the groove 162 and the portion of the second surface 220 and the portion of the fourth surface 240.

[0142] According to this, the groove 162 effectively increases the bonding area between the second substrate 160 and the heat sink 200, which may increase the bonding strength between the second substrate 160 and the heat sink 200. In addition, the adhesive layer 300 disposed between both wall surfaces 162-2, 162-3 of the groove 162 and a portion of the second surface 220 and a portion of the fourth surface 240 may increase the number of paths through which air bubbles in the adhesive layer 300 can escape.

[0143] The sum of the distances between both wall surfaces 162-2, 162-3 of each groove 162 and the patterns accommodated in each groove 162 may be 0.2 to 1.0 mm. In this way, the first surface 210 of each pattern of the heat sink 200 can be accommodated in the groove 162 of the second substrate 160. For example, if the sum of the distances between both wall surfaces 162-2, 162-3 of each groove 162 and the patterns accommodated in each groove 162 is less than 0.2 mm, a part of the pattern of the heat sink 200 may expand due to heat applied during the bonding process between the second substrate 160 and the heat sink 200, and may come off the groove 162, or may cause deformation of the groove 162 or a decrease in bonding strength, etc., which may result in a decrease in the characteristics of the heat sink 200. In addition, if the sum of the distance between both wall surfaces 162-2, 162-3 of each groove 162 and each pattern contained in each groove 162 exceeds 1.0 mm, the amount of solder to be applied will be excessively large, which will increase the possibility of air bubbles forming in the adhesive layer.

[0144] At this time, one wall surface 162-3 of the groove 162 and one wall surface 162-2 of the adjacent groove 162 may be connected to each other through a connection surface 162-4. At this time, the connection surface 162-4 may be disposed below the third surface 230 of the heat sink 200 and parallel to the third surface 230. Here, the distance T1 between the connection surface 162-4 and the third surface 230 may be 0.8 times or more and less than 1 time the vertical distance between the first surface 210 and the third surface 230. If the distance T1 between the connection surface 162-4 and the third surface 230 is less than 0.8 times the vertical distance between the first surface 210 and the third surface 230, the depth of the groove becomes excessively deep, increasing the amount of layer to be filled in the groove, and therefore increasing the possibility of air bubbles occurring in the adhesive layer. In addition, as the distance T1 between the connecting surface 162-4 and the third surface 230 becomes shorter, the area for air to flow is insufficient, and the pressure difference between the air before and after passing through the heat sink 200 area may increase.

[0145] Meanwhile, referring to FIG. 17, the adhesive layer 300 may be further disposed on at least a portion of the boundary between the wall surfaces 162-2, 162-3 and the connecting surface 162-4 of each groove 162. This may be formed by applying the adhesive layer 300 in the groove 162 of the second substrate 160, disposing the first surface 210 of the heat sink 200 on the adhesive layer 300, and then applying pressure, so that the adhesive layer 300 flows along the wall surfaces 162-2, 162-3 of the groove 162 onto the connecting surface 162-4 and then hardens. According to this, the adhesive layer 300 is disposed not only on the lower surface of the first surface 210 but also on the connecting surface 162-4 of the groove 162 together with the second surface 220 and the third surface 230, so that not only the bonding area between the second substrate 160 and the heat sink 200 is increased, but also air bubbles may be more easily released from the adhesive layer 300 due to the adhesive layer 300 protruding onto the connecting surface 162-4.

[0146] 18, a notch may be further formed in the groove 162. Here, the notch may mean a small groove, and may be formed in various shapes such as a V-shape, a U-shape, etc. For example, at least one notch 164 may be further formed along a boundary between the bottom surface 162-1 and both side surfaces 162-2, 162-3 of the groove 162, or at least one notch 164 may be further formed in a direction perpendicular to the bottom surface 162-1 on at least one of the both side surfaces 162-2, 162-3 of the groove 162, and an adhesive layer 300 may be further disposed in the formed notch 164.

[0147] This not only increases the bonding area between the second substrate 160 and the heat sink 200, thereby increasing the bonding strength between the second substrate 160 and the heat sink 200, but also increases the number of paths through which air bubbles in the adhesive layer 300 can escape through the notches.

[0148] On the other hand, the above-described embodiments may be combined with each other.

[0149] 19 to 22 are cross-sectional views of a portion of a thermoelectric module according to still other embodiments of the present invention.

[0150] 19, the embodiment according to Fig. 5 and the embodiment according to Fig. 9 may be combined. That is, the width of the first surface 210 of the heat sink 200 is formed narrower than the width of the third surface 230, but the hole 212 may be formed in the first surface 210.

[0151] 20, the embodiment of FIG. 5 and the embodiment of FIG. 16 may be combined. That is, the width of the first surface 210 of the heat sink 200 is formed narrower than the width of the third surface 230, but a groove 162 may be formed in the second substrate 160 and the first surface 210 may be disposed in the groove 162.

[0152] 21, the embodiment according to Fig. 5, the embodiment according to Fig. 9, and the embodiment according to Fig. 16 may be combined. That is, although the width of the first surface 210 of the heat sink 200 is formed narrower than the width of the third surface 230, a hole 212 may be formed in the first surface 210, a groove 162 may be formed in the second substrate 160, and the first surface 210 may be disposed in the groove 162.

[0153] 22, the embodiment according to FIG. 9 and the embodiment according to FIG. 16 may be combined. That is, although the hole 212 is formed in the first surface 210, the groove 162 may be formed in the second substrate 160, and the first surface 210 may be disposed in the groove 162.

[0154] In addition, embodiments of the present invention may be combined in various ways.

[0155] The thermoelectric module according to the embodiment of the present invention described above can be applied to a thermal conversion device.

[0156] FIG. 23 is a perspective view of an example of a heat exchanger to which a thermoelectric module according to an embodiment of the present invention is applied, and FIG. 24 is an exploded perspective view of the heat exchanger of FIG.

[0157] 23 and 24, the thermal exchange device 1000 includes a duct 1100, a first thermoelectric module 1200, a second thermoelectric module 1300, and a gas guide member 1400. Here, the thermal exchange device 1000 can generate electricity by utilizing the temperature difference between a cooling fluid flowing through the inside of the duct 1100 and a high-temperature gas passing through the outside of the duct 1100.

[0158] For this purpose, the first thermoelectric module 1200 may be disposed on one surface of the duct 1100, and the second thermoelectric module 1300 may be disposed on the other surface of the duct 1100. In this case, of both surfaces of the first thermoelectric module 1200 and the second thermoelectric module 1300, the surface that faces the duct 1100 becomes a low-temperature part, and electricity can be generated by utilizing the temperature difference between the low-temperature part and the high-temperature part.

[0159] The cooling fluid flowing into the duct 1100 may be water, but is not limited thereto, and may be various types of fluids having cooling properties. The temperature of the cooling fluid flowing into the duct 1100 may be, but is not limited thereto, less than 100° C., preferably less than 50° C., and more preferably less than 40° C. The temperature of the cooling fluid discharged after passing through the duct 1100 may be higher than the temperature of the cooling fluid flowing into the duct 1100.

[0160] The cooling fluid flows into the duct 1100 through a cooling fluid inlet and is discharged through a cooling fluid outlet.

[0161] Although not shown, heat dissipation fins may be disposed on the inner wall of the duct 1100. The shape, number, and area of ​​the inner wall of the duct 1100 of the heat dissipation fins may be variously changed depending on the temperature of the cooling fluid, the temperature of the waste heat, the required power generation capacity, etc.

[0162] Meanwhile, the first thermoelectric module 1200 is disposed on one side of the duct 1100 , and the second thermoelectric module 1300 is disposed on the other side of the duct 1100 so as to be symmetrical to the first thermoelectric module 1200 .

[0163] Here, the first thermoelectric module 1200 and the second thermoelectric module 1300 arranged symmetrically to the first thermoelectric module 1200 may be referred to as a pair of thermoelectric modules or a unit thermoelectric module.

[0164] The duct 1100 may further include a gas guide member 1400, a sealing member 1800, and a heat insulating member 1700 arranged in the direction of air flow.

[0165] However, application examples of the thermoelectric module according to the embodiment of the present invention are not limited thereto.

[0166] The thermoelectric module according to the embodiment of the present invention may be used in power generation devices, cooling devices, heating devices, etc. In particular, the thermoelectric module according to the embodiment of the present invention may be mainly applied to optical communication modules, sensors, medical devices, measuring devices, the aerospace industry, refrigerators, chillers, automobile ventilation seats, cup holders, washing machines, dryers, wine cellars, water purifiers, power supply devices for sensors, thermopiles, etc.

[0167] In addition, the thermoelectric module according to the embodiment of the present invention may be applied to other industrial fields for power generation, cooling, and heating.

[0168] Although the present invention has been described above with reference to preferred embodiments, those skilled in the art will understand that various modifications and variations of the present invention can be made without departing from the spirit and scope of the present invention as set forth in the following claims.

Claims

1. a thermoelectric element including a first substrate, a first electrode disposed on the first substrate, a semiconductor structure disposed on the first electrode, a second electrode disposed on the semiconductor structure, and a second substrate disposed on the second electrode; a heat sink disposed on the second substrate; and an adhesive layer that bonds the second substrate and the heat sink; The heat sink has a shape in which a predetermined pattern is regularly repeated and connected, Each pattern is a first surface disposed to face the second substrate; a second surface extending upward from one end of the first surface; a third surface extending from the second surface to face the second substrate; and a fourth surface extending upward from an end opposite to the one end of the first surface and connected to the third surface of an adjacent pattern; a distance between the third surface and the second substrate is greater than a distance between the first surface and the second substrate; the adhesive layer is disposed between the second substrate and the first surface; a thermoelectric module, wherein at least one slit is formed along at least one of a boundary between the first surface and the second surface and a boundary between the first surface and the fourth surface, and the adhesive layer protrudes above the first surface through the at least one slit.

2. The thermoelectric module of claim 1 , wherein the second substrate is formed with a plurality of regularly repeated grooves, and the adhesive layer and the first surface are disposed within each groove.

3. 3. The thermoelectric module of claim 2, wherein the plurality of grooves include a first groove and a second groove arranged adjacent to each other, one wall surface of the first groove and one wall surface of the second groove are connected to each other through a connecting surface arranged to face the third surface, and the adhesive layer is further arranged on at least a portion of the boundary between the wall surface of each groove and the connecting surface.

4. The thermoelectric module of claim 3 , wherein the adhesive layer is not disposed on at least a portion of the connecting surface corresponding to a midpoint of the width of the third surface.

5. The thermoelectric module of claim 1 , wherein the first surface has a plurality of holes formed therein.

6. The thermoelectric module of claim 5 , wherein the adhesive layer protrudes above the first surface through at least some of the holes.

7. A thermoelectric module as described in claim 1, wherein the width of the third surface in the direction from the second surface to the fourth surface is greater than the width of the first surface.

8. The thermoelectric module of claim 1 , wherein the adhesive layer comprises a polymer resin and a metal material.

9. The thermoelectric module of claim 8 , wherein the metallic material includes at least one of tin (Sn), silver (Ag), copper (Cu) and aluminum (Al).

10. The thermoelectric module of claim 8 , wherein the first surface is in direct contact with the adhesive layer.

11. The thermoelectric module of claim 8 , wherein the first surface has a plurality of holes formed therein.

12. The second substrate has a plurality of regularly repeated grooves formed thereon; The thermoelectric module of claim 7 , wherein the adhesive layer and the first surface are disposed within each groove.

13. A plurality of holes are formed in the first surface, The second substrate has a plurality of regularly repeated grooves formed thereon; The thermoelectric module of claim 7 , wherein the adhesive layer and the first surface are disposed within each groove.

14. The thermoelectric module of claim 2 , wherein the first surface has a plurality of holes formed therein.

15. At least one notch is formed within each groove; The thermoelectric module of claim 2 , wherein the adhesive layer is further disposed in the at least one notch.

16. The thermoelectric module of claim 5 , wherein at least one of the plurality of holes has a diameter at a lowest point on the first surface that is different from a diameter of the hole at a highest point on the first surface.

17. duct, a thermoelectric module disposed on the duct; The thermoelectric module includes: a thermoelectric element including a first substrate, a first electrode disposed on the first substrate, a semiconductor structure disposed on the first electrode, a second electrode disposed on the semiconductor structure, and a second substrate disposed on the second electrode; a heat sink disposed on the second substrate; and an adhesive layer that bonds the second substrate and the heat sink; The heat sink has a shape in which a predetermined pattern is regularly repeated and connected, Each pattern is a first surface disposed to face the second substrate; a second surface extending upward from one end of the first surface; a third surface extending from the second surface to face the second substrate; and a fourth surface extending upward from an end opposite to the one end of the first surface and connected to the third surface of an adjacent pattern; a distance between the third surface and the second substrate is greater than a distance between the first surface and the second substrate; the adhesive layer is disposed between the second substrate and the first surface; A power generating device, wherein at least one slit is formed along at least one of the boundary between the first surface and the second surface and the boundary between the first surface and the fourth surface, and the adhesive layer protrudes above the first surface through the at least one slit.

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