Wafer-level thermoelectric energy harvester

Abstract

The present invention relates to a wafer-level thermoelectric energy harvester. An integrated circuit may include a substrate and a dielectric layer formed on the substrate. A plurality of p-type thermoelectric elements and a plurality of n-type thermoelectric elements may be disposed within the dielectric layer. The p-type thermoelectric elements and the n-type thermoelectric elements may be connected in series and may alternate between the p-type and n-type thermoelectric elements simultaneously.

Description

[0001] This application is a divisional application of the invention patent application with the application date of May 8, 2015, application number 201510229765.7, and invention title "Wafer - level Thermoelectric Energy Harvester".

[0002] Related Applications

[0003] This application is a continuation - in - part of U.S. Application Serial No. 13 / 736,783, filed on January 8, 2013, which is hereby incorporated by reference. Technical Field

[0004] The subject matter of this application relates to thermoelectric energy harvesting and, more particularly, to an integrated single - chip thermoelectric power harvesting. Background Art

[0005] A thermoelectric device converts heat (e.g., thermal energy) into electrical energy. A temperature difference between the hot side and the cold side of the thermoelectric device moves charge carriers in the semiconductor material of the thermoelectric device to generate electrical energy. The material of the thermoelectric device is selected such that it is a good electrical conductor to allow current flow, but a poor thermal conductor to maintain the necessary heat difference between the two sides of the thermoelectric device. When one side of the thermoelectric element is placed near a heat source (e.g., an engine or a circuit), a temperature difference can be generated such that one side of the thermoelectric element is hotter.

[0006] The amount of energy generated by the thermoelectric device depends at least on the temperature difference, the type of material in the thermoelectric device, and the size of the thermoelectric device. For example, a larger temperature difference between the hot side and the cold side of the device can generate a greater current flow. Additionally, a thermoelectric device with a larger surface area and / or larger material for generating current flow conventionally generates more electrical energy. These different factors depend on the application for which the thermoelectric device is used.

[0007] There is increasing interest in shrinking the size of thermoelectric devices for new applications (e.g., self - sustainable sensors or mobile devices) and producing thermoelectric devices that can be part of an integrated circuit. However, scaling down the size of thermoelectric elements introduces new challenges, such as generating sufficient energy and keeping the manufacturing cost low. Additionally, conventional materials and / or material arrangements within the thermoelectric device may not provide the required energy for certain applications. Other challenges include dealing with parasitic heat losses that affect adjacent components in an integrated circuit.

[0008] Accordingly, the inventors have determined that there is a need in the art for small - scale thermoelectric devices that include high energy density, are low - cost, and address parasitic heat losses. Brief Description of the Drawings

[0009] Accordingly, the features of the present invention can be understood, and the descriptions of the multiple drawings are as follows. It should be noted, however, that the appended drawings merely illustrate specific embodiments of the present disclosure and should not be considered as limiting its scope, as the present invention may include other equally effective embodiments.

[0010] Figure 1A and 1B shows an exemplary configuration of a thermoelectric energy harvester according to an embodiment of the present invention.

[0011] Figure 2 shows a perspective view of a thermoelectric energy harvester 100 according to an embodiment of the present invention.

[0012] Figure 3 shows an exemplary configuration of a thermoelectric energy harvester according to another embodiment of the present invention.

[0013] Figure 4 shows an exemplary configuration of a thermoelectric energy harvester having a capping structure according to an embodiment of the present invention.

[0014] Figure 5 shows an exemplary configuration of a thermoelectric energy harvester according to another embodiment of the present invention.

[0015] Figures 6A - 6C shows an exemplary configuration of a thermoelectric energy harvester according to another embodiment of the present invention.

[0016] Figures 7A - 7C shows an exemplary configuration of a thermoelectric energy harvester according to another embodiment of the present invention.

[0017] Figure 8 shows an exemplary configuration of a thermoelectric power harvester according to an embodiment of the present invention.

[0018] Figures 9A - 9B shows an exemplary configuration of a thermoelectric energy harvester according to another embodiment of the present invention. Detailed Description

[0019] Embodiments of the present invention may provide a thermoelectric energy harvester that can be provided in an integrated circuit. In one embodiment, the integrated circuit may include a substrate and a dielectric layer formed on the substrate. A plurality of p-type thermoelectric elements and a plurality of n-type thermoelectric elements may be disposed within the dielectric layer. The p-type thermoelectric elements and the n-type thermoelectric elements may be electrically connected in series in an alternating manner. In response to heat being applied to one side of the thermoelectric elements, an electron flow may be generated in each thermoelectric element to provide electrical energy.

[0020] In another embodiment, when alternating between p-type and n-type thermoelectric elements, a cap may be disposed on the substrate to surround a plurality of p-type and n-type thermoelectric elements disposed and serially connected on the substrate. A vacuum or low pressure may be maintained between the thermoelectric elements. The cap and the vacuum or low pressure may reduce parasitic thermal losses to the surrounding area of the integrated circuit, thereby maintaining a large thermal gradient along the thermoelectric elements.

[0021] In one embodiment, a seal may be formed by a dummy structure surrounding the active thermoelectric elements. A vacuum or low pressure may be maintained within and / or between the thermoelectric elements for the seal. The dummy structure may be in the form of a ring and may be formed using some of the same steps in the manufacturing process used to form the active thermoelectric elements. The seal may also be used to prevent contaminants from entering the active thermoelectric elements during manufacturing.

[0022] In one embodiment, the active thermoelectric elements may be tilted horizontally and vertically, i.e., tilted in two dimensions with respect to the direction of the thermal gradient of the entire integrated circuit, so as to maximize the thermal length (the length of the flow of thermal energy) through each active thermoelectric element.

[0023] In one embodiment, all of the plurality of serially connected thermoelectric elements may include only one type of thermoelectric element, i.e., only n-type or only p-type serially connected. A pure n-type or pure p-type thermoelectric energy harvester may be simpler to manufacture using fewer process steps.

[0024] Figure 1A An exemplary configuration of a thermoelectric energy harvester 100 according to an embodiment of the present invention is shown. The thermoelectric energy harvester 100 may include thermoelectric elements 110A, 110B above a substrate layer 130 and within a dielectric layer 120. The plurality of thermoelectric elements 110A, 110B may include elements of different types of thermoelectric materials (e.g., p-type and n-type). The thermoelectric elements 110A, 110B may be interconnected such that in response to a temperature gradient between a first side (e.g., the hot side) and a second side (e.g., the cold side), each thermoelectric element contributes to the total energy provided by the thermoelectric energy harvester 100. A thermal contact layer 140 may be provided above the dielectric layer 120 to support the temperature gradient between the first side and the second side. The thermal contact layer 140 may be made of a material that is a good thermal conductor.

[0025] As Figure 1A shown, the thermoelectric energy harvester 100 may include a vertical structure with a dielectric layer 120 provided and may be formed as a single wafer. The wafer-level structure of the thermoelectric energy harvester 100 allows it to be integrated with other integrated circuit components ( Figure 1A not shown) above or adjacent to the substrate 130.

[0026] As shown, the thermoelectric elements 110A, 110B may include different types of thermoelectric materials (e.g., p-type and n-type). In response to a temperature difference between two ends, the thermoelectric materials of the thermoelectric elements 110A, 110B may be selected to generate a flow of charge carriers of different polarities from one end of the thermoelectric element to the opposite end. In the thermoelectric element 110A including p-type material, positive charge carriers flow from the hot end to the relatively cold end. In contrast, in the thermoelectric element 110B including n-type material, electrons flow from the end with the heat source to the relatively colder opposite end.

[0027] Multiple thermoelectric elements 110A, 110B may be connected in an array and alternate the type of material (e.g., between n-type and p-type) in adjacent thermoelectric elements 110A and 110B. In this way, the voltages and / or currents developed across the thermoelectric elements 110A and 110B may be summed together to produce a greater aggregate voltage and / or current than that achieved by the thermoelectric elements 110A and 110B separately. For example, the thermoelectric element 110A having p-type material may be connected in series with the thermoelectric element 110B having n-type material. The thermoelectric elements 110A, 110B may be arranged such that all adjacent thermoelectric elements of a given thermoelectric element include a material type different from that of the given thermoelectric element. The outputs of the array of thermoelectric elements 110A and 110B may be connected in parallel to provide the required energy in a particular application. The interconnections 150 may connect the thermoelectric elements 110A and 110B to adjacent thermoelectric elements 110A and 110B.

[0028] Although each thermoelectric element 110A, 110B may provide a small amount of energy (e.g., millivolts), connecting the thermoelectric elements 110A, 110B in an array may provide the higher energy required for a particular application. When heat is applied to one side of the thermoelectric energy harvester 100, electrons in the thermoelectric element 110A having p-type material will flow from the low-temperature side to the high-temperature side of the thermoelectric element 110A, and electrons in the thermoelectric element 110B having n-type material will flow from the high-temperature side to the low-temperature side of the thermoelectric element 110B. Thus, if the thermoelectric element 110A is connected in series with the thermoelectric element 110B, forming a thermocouple, electrons will flow from the cold side of the p-type material to the hot side of the p-type material, enter the hot side of the n-type material via the interconnection 150, and enter the cold side of the n-type material. The energy generated by each of the thermoelectric elements 110A, 110B is combined and provided at the output of the thermoelectric energy harvester 100.

[0029] Figure 1B Shown equivalent to Figure 1AThe circuit of the thermoelectric energy harvester 100 as shown. The voltages developed across the thermoelectric elements 110A and 110B are represented by Vp and Vn. The individual voltages and / or currents can be added together to provide an aggregated output voltage Vout, and in the case of a drain, the voltages are added to obtain a useful voltage that can drive a conventional low-power electronic circuit.

[0030] Figure 1A Not drawn to scale, but depicts the approximate dimensions of the collector 100 in one embodiment. The thermoelectric elements 110A, 110B can have a shape that maximizes the surface of the thermoelectric elements 110A, 110B adjacent to the dielectric layer 120. The thermoelectric elements 110A, 110B can have a rectangular shape with longer ends adjacent to the dielectric layer 120 on two sides and short sides adjacent to the interconnect 150. In another embodiment, at least one side of the thermoelectric elements 110A, 110B can also be square.

[0031] The materials of the thermoelectric elements 110A, 110B can be selected such that the thermal resistors of the thermoelectric elements 110A, 110B are less than the thermal resistance of the dielectric layer 120, so that the dielectric layer does not cause too much thermal shunting. The high thermal resistance of the thermoelectric elements 110A, 110B still needs to ensure that a good temperature difference is maintained between the hot and cold sides of the thermoelectric elements 110A, 110B. The thermal resistance of the thermoelectric elements 110A, 110B can be increased by controlling the doping level of the thermoelectric elements 110A, 110B or by introducing scattering elements to increase the photon scattering of the thermoelectric elements 110A, 110B without affecting the electrical conduction too much. The doping level or the concentration of the scattering elements can be increased or decreased at one end of the thermoelectric elements 110A, 110B compared to the opposite ends of the thermoelectric elements 110A, 110B.

[0032] For example, the thermoelectric element 110A can be p-type BixSb2-xTe3, and the thermoelectric element 110B can be n-type Bi2Te3-xSex. The dielectric layer 120 can be polyimide because it has low thermal conductivity and helps in the processing of the thermoelectric elements. The thermal contact layer 140 can be any electrically insulating but thermally conductive layer. In one embodiment, the thermal contact layer 140 can consist of multiple layers. For example, the thermal contact layer 140 can include a thin non-conductive layer such as an oxide or a nitride and one or more thicker metal layers at the top to improve heat conduction. The thermal contact layer 140 can provide insulation to the electrical interconnect layer 150 at the interface to prevent electrical short circuits of the electrical interconnect layer 150. The substrate 130 can be any semiconductor substrate with sufficient thickness to facilitate heat conduction on the bottom side. Although the configuration with the substrate 130 as the cold side and the top thermal contact layer 140 as the hot side is shown, the device can also be with the substrate 130 as the hot side and the top thermal contact layer 140 as the cold side.

[0033] The interconnect 150 can be included on the hot and cold sides of the thermoelectric elements to connect adjacent thermoelectric elements. The thermoelectric elements can include a first interconnect coupled to the hot side of the first thermoelectric element and a second interconnect coupled to the cold side of the second thermoelectric element. The interconnects 150 of the first and last thermoelectric elements 110A, 110B can be output terminals to connect to other circuit elements (e.g., an external circuit, a load, or an energy storage device). The interconnect 150 can include a semiconductor material or a metal connector (e.g., gold, copper, or aluminum).

[0034] In an exemplary embodiment, the dielectric layer 120 can be a material with high dielectric breakdown, such as polyimide, silicon dioxide, silicon nitride, etc. The dielectric layer 120 can electrically insulate the thermoelectric elements 110A, 110B. The dielectric layer 120 can inhibit heat conduction away from the thermoelectric elements 110A, 110B. The dielectric layer 120 can have a lower thermal conductivity than that of the substrate 130 and / or the thermoelectric elements 110A, 110B. The dielectric layer 120 can surround the thermoelectric elements 110A, 110B on four sides to thermally shunt the thermoelectric elements 110A, 110B and allow a thermal gradient to be developed across the thermoelectric elements 110A, 110B and allow most of the heat to go to the sides of the thermoelectric energy collector 100. Compared with the thermal resistance of the substrate 130 and / or the thermal contact layer 140, the high thermal resistance of the thermoelectric elements 110A, 110B causes the thermal gradient to drop across the thermoelectric elements rather than the thermal contact layer or the substrate 130. Therefore, the maximum temperature difference is maintained between the hot and cold sides of the thermoelectric elements 110A, 110B.

[0035] The barrier metal 160 can be included between the thermoelectric elements 110A, 110B and the interconnect 150 to isolate the semiconductor material of the thermoelectric elements 110A, 110B from the metal interconnect 150 while maintaining the electrical connection between the thermoelectric elements 110A, 110B and the interconnect 150. The barrier metal 160 can be included to prevent the interconnect 150 from diffusing into the semiconductor material of the thermoelectric elements 110A, 110B.

[0036] When heat is applied to one side (e.g., the hot side) of the thermoelectric energy collector 100, electrons flow in one direction in the thermoelectric element with the p-type material 110A and in the other direction in the thermoelectric element 110B with the n-type material. Since the thermoelectric elements 110A, 110B are connected in series, the energy generated in each thermoelectric element 110A, 110B is combined to provide combined energy at the output of the thermoelectric energy collector 100. The incoming heat is distributed by the thermal contact layer 140 to the hot sides of the thermoelectric elements 110A, 110B, and at the same time the substrate 130 cools the low-temperature sides of the thermoelectric elements 110A, 110B.

[0037] Figure 2 A perspective view of a thermoelectric energy collector 200 according to an embodiment of the present disclosure is shown. AsFigure 2 As shown, thermoelectric elements 210A and 210B are above substrate layer 230. Dielectric layer 220 is disposed above substrate layer 230 to electrically isolate the thermoelectric elements 210A and 210B from each other. The thermoelectric elements 210A and 210B may be arranged in an array such that in adjacent thermoelectric elements 210A and 210B, the types of the thermoelectric elements 210A and 210B alternately change (e.g., between n-type and p-type) simultaneously. Interconnects 250 may serially connect the thermoelectric elements 210A and 210B. Thermal contact layer 240 may disperse the applied heat to the thermoelectric elements 210A and 210B.

[0038] Figure 3 An exemplary configuration of a thermoelectric energy harvester 300 according to another embodiment of the present invention is shown. The thermoelectric energy harvester 300 may include a plurality of thermoelectric elements 310A and 310B within dielectric layer 320 above substrate layer 330 and above substrate layer 330. The thermoelectric elements 310A and 310B may be arranged in an array while alternately changing the types of materials (e.g., between n-type and p-type) in adjacent thermoelectric elements 310A and 310B. The plurality of thermoelectric elements 310A and 310B may be serially connected via interconnects 350. Thermal contact layer 340 may be provided above the thermoelectric elements 310A and 310B to dissipate the heat applied to the thermoelectric energy harvester 300.

[0039] The thermoelectric energy harvester 300 may include an additional substrate layer 370 between thermal contact layer 340 and dielectric layer 320. The substrate layer 370 may have a high thermal conductivity to dissipate heat from an external heat source. The substrate layer 370 may be an aluminum nitride substrate.

[0040] The thermoelectric energy harvester 300 may include one or more circuit elements 380 in substrate 330 and / or on the surface of substrate 330. The circuit element 380 may couple to the output of the thermoelectric energy harvester 300. The circuit component 380 may receive the energy generated by the thermoelectric energy harvester 300 and / or control the thermoelectric energy harvester 300. The circuit element 380 may be part of a sensor powered by the thermoelectric energy harvester 300 (e.g., an automotive sensor, a medical implant, and / or a wireless sensor). In one embodiment, current may be provided to the thermoelectric elements 310A and 310B of the thermoelectric energy harvester 300 via the circuit element 380 to be used as a cooler. The thermoelectric energy harvester 300 acting as a cooler may cool the circuit element 380 within substrate 330 or disposed close to or above the surface of the substrate. The current applied to the thermoelectric elements 310A and 310B may generate a flow of charge carriers, which may generate a temperature difference between both sides of the thermoelectric energy harvester 300, which can be used to cool the circuit element 380.

[0041] A barrier metal 360 may be included between the thermoelectric elements 310A, 310B and the interconnect 350 to isolate the semiconductor materials of the thermoelectric elements 310A, 310B and the metal interconnect 350 while maintaining electrical connection between the thermoelectric elements 310A, 310B and the interconnect 350.

[0042] Figure 4 An exemplary configuration of a thermoelectric energy harvester 400 having a capping structure in accordance with an embodiment of the present disclosure is shown. The thermoelectric energy harvester 400 may include a capped substrate 470 to enclose the thermoelectric elements 410A, 410B provided above the substrate 430. The capped substrate 470 may permit a low pressure or a vacuum to be maintained between the substrate 430 and the capped substrate 470.

[0043] The capped substrate 470 may enclose the thermoelectric elements 410A, 410B between the capped substrate 470 and the substrate 410. The capped substrate 470 may be attached to the substrate 410 under pressure or vacuum such that a low pressure or vacuum setting surrounds the thermoelectric elements 410A, 410B.

[0044] The capped substrate 470 and / or the low pressure or vacuum may reduce parasitic thermal losses in the area surrounding the thermoelectric elements 410A, 410B. Reducing parasitic thermal losses enables the thermoelectric energy harvester 400 to be scaled down and included as part of an integrated circuit. Reducing parasitic thermal losses at small scales enables other circuits to be included with the thermoelectric energy harvester 400.

[0045] The capped substrate 470 may permit more energy to be harvested by the thermoelectric energy harvester 400. A vacuum or low pressure harvest allows the temperature gradient between the hot and cold sides of the thermoelectric elements 410A, 410B to be maximized.

[0046] Similar to the embodiments shown in FIGS. 1-3, the thermoelectric elements 410A, 410B may be arranged in an array having alternating material types (e.g., between n-type and p-type) in adjacent thermoelectric elements 410A and 410B. A plurality of thermoelectric elements 410A, 410B may be connected in series via an interconnect 450. A thermal contact layer 440 may be provided over the thermoelectric elements 410A, 410B to dissipate heat from the thermoelectric elements 410A, 410B.

[0047] A barrier metal 460 may be included between the thermoelectric elements 410A, 410B and the interconnect 450 to isolate the materials of the thermoelectric elements 410A, 410B from the interconnect 450 while maintaining electrical connection between the thermoelectric elements 410A, 410B and the interconnect 450.

[0048] In one embodiment, before bonding the capping substrate 470 to the substrate 430, both p-type and n-type can be disposed on one of the capping substrate 470 and the substrate 430. In another embodiment, before bonding the capping substrate 470 to the substrate 430, p-type thermoelectric elements can be disposed on one of the capping substrate 470 and the substrate 430, and n-type thermoelectric elements can be disposed on the other of the capping substrate 470 and the substrate 430. Bonding the capping substrate 470 to the substrate 430 will couple the p-type thermoelectric elements and the n-type thermoelectric elements.

[0049] As shown in FIGS. 1-4, the thermoelectric elements are shown as having a rectangular vertical structure. However, the thermoelectric elements can include various shapes and orientations. Figure 5 An exemplary configuration of another embodiment of a thermoelectric energy harvesting 500 according to the present invention is shown. The thermoelectric energy harvester 500 can include a plurality of thermoelectric elements 510A, 510B within a dielectric layer 520 above a substrate layer 530 and above the thermoelectric element 510A of the substrate layer 530, 510B can be arranged in an array while alternating the types of materials (e.g., between n-type and p-type) in adjacent thermoelectric elements 510A and 510B. The plurality of thermoelectric elements 510A, 510B can be connected in series, and via an interconnect 550 a layer 540 can provide a thermal contact to the above-mentioned thermoelectric elements 510A, 510B to dissipate heat applied to the thermoelectric energy harvester 500.

[0050] As Figure 5 shown, the thermoelectric elements 510A and 510B can be inclined. In addition, the thermoelectric elements 510A and 510B can include one or more connecting portions 510C at both ends of the thermoelectric elements 510A and 510B connected to the interconnect 550. The dielectric layer 520 can allow the thermoelectric elements 510A and 510B to include various shapes and orientations. The orientation and / or shape of the thermoelectric elements 510A and 510B can be changed based on the available space for the thermoelectric energy harvester 500 and / or the performance requirements of the system. Changing the orientation of the thermoelectric elements 510A and 510B may reduce the available space (e.g., vertical space), while maximizing the surface area of the thermoelectric elements 510A and 510B adjacent to the dielectric layer 520.

[0051] Figure 6AShows an exemplary configuration of a thermoelectric energy harvester 600 according to an embodiment of the present invention. The thermoelectric energy harvester 600 may include a plurality of thermoelectric elements 610A, 610B above a substrate layer 630. The thermoelectric elements 610A, 610B may include elements of different types of thermoelectric materials (e.g., p-type and n-type). The thermoelectric elements 610A, 610B may be interconnected such that in response to a temperature gradient between a first side (e.g., the hot side) and a second side (e.g., the cold side), each thermoelectric element contributes to the total energy provided by the thermoelectric energy harvester 600. A capping substrate 640 may be provided above the thermoelectric elements 610A, 610B to support the temperature gradient between the first side and the second side. The capping substrate 640 may be made of a material that is a good thermal conductor.

[0052] A dummy structure 670 may be provided around the thermoelectric elements 610A, 610B to form a seal around the thermoelectric elements 610A, 610B in a horizontal direction. A vacuum or low pressure may maintain the seal between and / or within the thermoelectric elements. The dummy structure 670 may be in the form of a ring and may be formed using some of the same steps of the manufacturing process used to form the active thermoelectric elements. The seal may also be used to prevent contaminants from entering the active thermoelectric elements during the manufacturing process. Additionally, the dummy structure 670 may reduce heat conduction, thereby reducing heat loss in the horizontal direction.

[0053] As Figure 6A shown, the thermoelectric energy harvester 600 may be formed with the thermoelectric elements 610A, 610B on two different substrates 630 and 640, respectively. Here, for example, the substrate 640 may be formed as an N-type element, and the substrate 630 may be formed as a p-type element. The dummy structure 670 may also be formed on one of the substrates 630 and 640. The dummy structure 670 may be made from an n-type thermoelectric material or a p-type thermoelectric material, but may also be rendered inactive by disconnecting the dummy structure 670. In doing so, the dummy structure 670 may be formed as part of the manufacturing process that uses the same steps for forming the thermoelectric elements 610A and 610B without the need for additional steps.

[0054] In one embodiment, the dummy structure 670 may be made of a polyimide material because it has a low thermal conductivity and facilitates the processing of the thermoelectric elements.

[0055] During manufacturing, the capped substrate may have scribe lines / notches 690 cut or etched into the substrate 640 to define the outlines of individual integrated circuit dies. The capped substrate 640 may be inverted, aligned, and mounted (via metal interconnects) to the substrate 630 such that the thermoelectric elements 610A and 610B are connected to various interconnects 650 to form a string of alternating thermoelectric elements 610A and 610B in a circuit path. Additionally, a dummy structure 670 may also be attached between the substrates 630 and 640 to form a seal. During the mounting process, a vacuum or low pressure may be formed between the thermoelectric elements 610A and 610B and inside the seal of the dummy structure 670. The capped substrate 640 may need to be ground to a thin layer (i.e., to a predetermined polish line 695). This may thin the capped substrate 640 and thus make it more thermally conductive, and also expose the scribe lines / notches 690.

[0056] Because the scribe lines / notches 690 may be exposed, without the seal of the dummy structure 670, contaminants and particles may be introduced between the thermoelectric elements 610A and 610B during the polishing step. Thus, the dummy structure 670 helps to form a vacuum or low pressure and prevent contamination during manufacturing.

[0057] The wafer-scale structure 600 of the thermoelectric energy harvester allows it to be integrated at or near the substrates 630 and 640 with other integrated circuit components ( Figure 6A not shown).

[0058] Figure 6B and 6C The formed harvester 600 is further shown. Figure 6B For example, the harvester 600 is shown after mounting the two substrates 630 and 640 and after completion of the polishing step that exposes the scribe lines / notches 690. Figure 6C A general top view of the harvester 600 and the ring seals of the thermoelectric elements 610A and 610B around the dummy structure 670 are shown.

[0059] As shown, the thermoelectric elements 610A, 610B may include different types of thermoelectric materials (e.g., p-type and n-type). In response to a temperature difference between two ends, the thermoelectric materials of the thermoelectric elements 610A, 610B may be selected to produce a flow of charge carriers of different polarities from one end of the thermoelectric element to the opposite end. In the thermoelectric element 610A including p-type material, positive charge carriers flow from the hot end to the opposite cold end. In contrast, in the thermoelectric element 610B including n-type material, electrons flow from the end with the heat source to the relatively colder opposite end.

[0060] Multiple thermoelectric elements 610A, 610B can be connected in an array, and the types of materials of adjacent thermoelectric elements 610A and 610B can be alternated (e.g., between n-type and p-type). In this way, the voltages and / or currents developed across the thermoelectric elements 610A and 610B can be summed together to produce a larger aggregated voltage and / or current than that achieved by the thermoelectric elements 610A and 610B separately. For example, a thermoelectric element 610A with p-type material can be connected in series with a thermoelectric element 610B with n-type material. The thermoelectric elements 610A, 610B can be arranged such that all adjacent thermoelectric elements of a given thermoelectric element include a material type different from that of the given thermoelectric element. The outputs of the array of thermoelectric elements 610A and 610B can be connected in parallel to provide the required energy in a particular application. The interconnections 650 can connect the thermoelectric elements 610A and 610B to adjacent thermoelectric elements 610A and 610B, and can further be connected to pads 680 (which can be used for bonding to external connections).

[0061] Although each thermoelectric element 610A, 610B can provide a small amount of energy (e.g., millivolts), connecting the thermoelectric elements 610A, 610B in an array can provide a higher energy required for a particular application. When heat is applied to one side of the thermoelectric energy collector 600, electrons in the thermoelectric element 610A with p-type material will flow from the low-temperature side of the thermoelectric element 610A to the hot side, and electrons in the thermoelectric element 610B with n-type material will flow from the hot side to the cold side of the thermoelectric element 610B. Thus, if the thermoelectric element 610A is connected in series with the thermoelectric element 610B to form a thermocouple, electrons will flow from the cold side of the p-type material to the hot side of the p-type material, enter the hot side of the n-type material via the interconnection 650, and enter the cold side of the n-type material. The energy generated by each of the thermoelectric elements 610A, 610B is combined and provided at the output of the thermoelectric energy collector 600.

[0062] Figure 6A is not drawn to scale, but depicts the approximate dimensions of the collector 600 in one embodiment. The thermoelectric elements 610A, 610B can have a shape that maximizes the length of the thermoelectric elements 610A, 610B. The thermoelectric elements 610A, 610B can have a rectangular shape with the sides having a longer length in the vertical direction than the shorter sides adjacent to the interconnection 650. In another embodiment, at least one side of the thermoelectric elements 610A, 610B can be square. Additionally, the dimensions of the dummy structure 670 can be such that the overall horizontal area of the seal formed by the dummy structure 670 is minimized relative to the lateral area of all the thermoelectric elements 610A, 610B sealed using the seal. This can help the collector 600 minimize heat conduction through the dummy structure 670 and also minimize heat loss in the horizontal direction.

[0063] For example, the thermoelectric element 610A can be p-type BixSb2-xTe3, and the thermoelectric element 610B can be n-type Bi2Te3-xSex. The capping substrate 640 can be formed of a semiconductor substrate (such as an n-type wafer) and can be a thermally conductive layer. In one embodiment, the capping substrate 640 can be composed of multiple layers. For example, the capping substrate 640 can include a thin non-conductive layer (such as an oxide or nitride) and one or more thicker top metal layers to enhance heat conduction. The capping substrate 640 can provide insulation to the electrical interconnect layer 650 at the interface to prevent electrical short circuits in the electrical interconnect layer 650. The substrate 630 can be any semiconductor substrate with sufficient thickness to facilitate heat conduction on the bottom side. Although the substrate 630 is shown as the cold side and the top capping substrate 640 as the hot side configuration, the device can also be used with the substrate 630 as the hot side and the top capping substrate 640 as the cold side.

[0064] The interconnect 650 can be included on the hot and cold sides of the thermoelectric elements to connect adjacent thermoelectric elements. The thermoelectric elements can include a first interconnect coupled to a first thermoelectric element on the hot side and a second interconnect connected to a second thermoelectric element on the cold side. The interconnects 650 of the first and last thermoelectric elements 610A, 610B can be output terminals connected to other circuit elements (such as an external circuit, a load, or an energy storage device). The interconnect 650 can include semiconductor materials or metal connectors (such as gold, copper, or aluminum).

[0065] The dummy structure 670 can surround the thermoelectric elements 610A, 610B on four sides to thermally shunt the thermoelectric elements 610A, 610B and allow a thermal gradient to be developed across the thermoelectric elements 610A, 610B, and allow most of the heat to travel to the sides of the thermoelectric energy harvester 600. Compared with the thermal resistance of the substrate 630 and / or the capping substrate 640, the relatively high thermal resistance of the thermoelectric elements 610A, 610B causes the thermal gradient to span the thermoelectric elements rather than the thermal contact layer or the substrate 630. Thus, the maximum temperature difference is maintained between the hot and cold sides of the thermoelectric elements 610A, 610B.

[0066] Although the seal of the dummy structure 670 can physically be a continuous ring without any openings to maintain a vacuum (or a separate gas) therein, if a vacuum (or a separate gas) therein is not required, then the dummy structure 670 can have openings in the horizontal direction.

[0067] A barrier metal 660 may be included between the thermoelectric elements 610A, 610B and the interconnect 650 to isolate the semiconductor materials of the thermoelectric elements 610A, 610B from the metal interconnect 650 while maintaining electrical connection between the thermoelectric elements 610A, 610B and the interconnect 650. The barrier metal 660 may be included to prevent the interconnect 650 from diffusing into the semiconductor materials of the thermoelectric elements 610A, 610B.

[0068] When heat is applied to one side (e.g., the hot side) of the thermoelectric energy harvester 600, electrons flow in one direction in the thermoelectric element having the p-type material 610A and in the other direction in the thermoelectric element 610B having the n-type material. Since the thermoelectric elements 610A, 610B are connected in series, each thermoelectric element 610A, 610B provides combined energy at the output of the thermoelectric energy harvester 600. The incoming heat is distributed by the capping substrate 640 to the hot sides of the thermoelectric elements 610A, 610B, while the substrate 630 cools the cold sides of the thermoelectric elements 610A, 610B.

[0069] Figures 7A - 7C An exemplary configuration of a thermoelectric energy harvester 700 according to another embodiment of the present invention is shown.

[0070] The thermoelectric energy harvester 700 may include a plurality of thermoelectric elements 710A, 710B between a substrate 730 and a capping substrate 740. The thermoelectric elements 710A, 710B may include alternating elements of different types of thermoelectric materials (e.g., p-type and n-type). The thermoelectric elements 710A, 710B may be electrically connected such that in response to a temperature gradient between a first side (e.g., the hot side) and a second side (e.g., the cold side), each thermoelectric element contributes to the total energy provided by the thermoelectric energy harvester 700.

[0071] As shown in FIG. 7, the thermoelectric elements 710A, 710B may have an operating length that is at least the height of the thermoelectric elements 710A, 710B. In one embodiment, the thermoelectric elements 710A, 710B may be inclined. The inclined thermoelectric elements 710A, 710B may have a rectangular or cylindrical shape. In another embodiment, the thermoelectric elements 710A, 710B may have a conical shape or a pyramidal shape. In one embodiment, in each row of thermoelectric elements, the thermoelectric element 710A may be inclined in one direction and the thermoelectric element 710B may be inclined in the opposite direction.

[0072] The various shapes of the thermoelectric elements 710A, 710B allow the thermoelectric energy collector 700 to have a semi-vertical or quasi-lateral structure. These shapes of the thermoelectric elements 710A, 710B may allow the thickness of the thermoelectric energy collector 700 to be reduced relative to the vertical thermoelectric elements shown in FIG. 1. The shape and depth of the thermoelectric elements 710A, 710B can be selected to maximize the surface area of the thermoelectric elements while keeping the thickness of the thermoelectric energy collector 700 fixed.

[0073] The thermoelectric elements 710A and 710B can be formed on a thermoplastic 720 (e.g., polyimide) having a low thermal conductivity. The thermoplastic 720 can provide support for the thermoelectric elements 710A and 710B. The support for the thermoelectric elements 710A and 710B can be provided on the inclined surface of the thermoplastic 720. The thermoplastic 720 can allow the thermoelectric elements 710A and 710B to include different shapes and orientations. The orientation and / or shape of the thermoelectric elements 710A and 710B can be changed based on the available space of the thermoelectric energy collector 700 and / or the performance requirements of the system. Changing the orientation and / or shape of the thermoelectric elements 710A and 710B can reduce the vertical space while maximizing the surface area and thermal length of the thermoelectric elements 710A and 710B.

[0074] The space 790 between the thermoelectric elements 710A and 710B and the second thermal conductor 730 can be unfilled (e.g., set with a vacuum). In one embodiment, the space 790 between the thermoelectric elements 710A and 710B and the capping substrate 740 can be filled with air or gas. In another embodiment, the space 790 between the thermoelectric elements 710A and 710B and the capping substrate 740 can be filled with a dielectric or polyimide.

[0075] The thermoelectric elements 710A and 710B can include connection portions 710C at one or both ends of the thermoelectric elements 710A and 710B connected to the interconnect 750. The interconnect 750, which can be copper or gold, can be deposited on the surfaces of the substrates 730 and 740. In one embodiment (not shown), the thermoelectric elements 710A and 710B can be directly connected through the interconnect 750 and via the connection portions 710C. The interconnect 750 can connect the thermoelectric elements 710A and 710B and adjacent thermoelectric elements 710A and 710B, and can further be connected to vias and pads 780 (which can be used for bonding to external connections).

[0076] The capping substrate 740 can be provided with additional interconnects 750 for connecting and integrating the collector 700. The wafer-scale structure of the thermoelectric energy collector 700 allows it to be integrated with other integrated circuit components (not shown) to form part of or near the thermoelectric energy collector 700.

[0077] Dummy structure 770 is formed on the thermoplastic 720A and can surround the thermoelectric elements 710A, 710B to form a seal around the thermoelectric elements 710A, 710B in the horizontal direction. A vacuum or low pressure can maintain the seal between and / or within the thermoelectric elements. The dummy structures 770 and 720A can be in the form of a ring and can be formed using some of the same steps as in the manufacturing process for forming the active thermoelectric elements. Seals can also be used to prevent contaminants from entering the active thermoelectric elements during manufacturing. Additionally, the dummy structures 770 and 720A can reduce heat conduction, thereby reducing heat loss in the horizontal direction.

[0078] The dummy structure 770 can be formed on the thermoplastic 720A from n-type or p-type thermoelectric materials, but can be made inactive by disconnecting the dummy structure 770. In doing so, using the same steps as for forming the thermoelectric elements 710A and 710B, the dummy structures 770 and 720A can be formed as part of the manufacturing process without the need for additional steps.

[0079] Without the seals of the dummy structures 770 and 720A, contaminants and particles can be introduced between the thermoelectric elements 710A and 710B during the polishing step. Thus, the dummy structures 770 and 720A help to form a vacuum or low pressure and prevent contamination during the manufacturing process.

[0080] Figure 7B Different versions of the collector 700 are shown. The interconnect 750 can be directly connected to the pad 780 (without using any additional metal layers and interconnects). This further reduces the number of steps in the manufacturing process. Here the dummy structure 770 further reduces the horizontal area to electrically isolate the metal interconnects on the bottom side of the thermoplastic 720A.

[0081] Figure 7C A general top view of the collector 700 with a ring seal having a dummy structure 770 around the thermoelectric elements 710A and 710B is shown. The dummy structure 770 (not shown) is formed on a ring of the thermoplastic 720A to form a seal around the thermoelectric elements 710A and 710B. The thermoelectric elements 710A and 710B are respectively formed on the thermoplastic 720, which is shown as an "island" inside the ring for example. Here, the thermoplastic "island" 720 is shown as being independent of the thermoplastic ring 720A. However, the thermoplastics 720 and 720A can be physically connected in a grid configuration.

[0082] Figure 8 An exemplary configuration of a thermoelectric energy collector 800 according to another embodiment of the present invention is shown.

[0083] The thermoelectric energy collector 800 can include being formed on a thermoplastic island 820 (similar to the thermoplastic in Figures 7A - 7Ca plurality of thermoelectric elements 810A, 810B on <720> and electrically connected by metal interconnects 850. The thermoelectric elements 810A, 810B may include alternating elements of different types of thermoelectric materials (e.g., p-type and n-type). The thermoelectric elements 810A, 810B may be electrically connected to each other such that in response to a temperature gradient between a first side (e.g., the hot side) and a second side (e.g., the cold side), each thermoelectric element contributes to the total energy provided by the thermoelectric energy harvester 800.

[0084] As Figure 8 shown, the thermoelectric elements 810A, 810B may have an operating length that is at least the height of the thermoelectric elements 810A, 810B. In one embodiment, the thermoelectric elements 810A, 810B may be tilted or skewed in both the horizontal and vertical directions simultaneously. The tilted thermoelectric elements 810A, 810B may have a rectangular or cylindrical shape. In another embodiment, the thermoelectric elements 810A, 810B may have a conical shape or a pyramidal shape. In one embodiment, in each row of thermoelectric elements, the thermoelectric element 810A may be tilted in one direction and the thermoelectric element 810B may be tilted in the opposite direction (horizontal and vertical directions), having a zigzag pattern.

[0085] The various shapes of the thermoelectric elements 810A, 810B allow the thermoelectric harvester 800 to have a semi-vertical or quasi-lateral structure. These shapes of the thermoelectric elements 810A, 810B may allow the thickness of the thermoelectric harvester 800 to be reduced compared to the thermoelectric elements shown in FIG. 1. The shape and depth of the thermoelectric elements 810A, 810B may be selected to maximize the surface area of the thermoelectric elements and keep the thickness of the thermoelectric harvester 800 fixed.

[0086] Thus, given the same overall size of the thermoelectric harvester 800, the thermoelectric elements 810A and 810B may be tilted horizontally and vertically, i.e., tilted in two dimensions with respect to the direction of the thermal gradient of the entire integrated circuit, in order to maximize the thermal length (the length of heat energy flow) through each active thermoelectric element.

[0087] Figure 9AShows an exemplary configuration of a thermoelectric energy harvester 900 according to an embodiment of the present invention. The thermoelectric energy harvester 900 may include a plurality of thermoelectric elements 910A over a substrate layer 930. The thermoelectric elements 910A within a series may include elements of the same type of thermoelectric material (e.g., only p-type or only n-type). The thermoelectric elements 910A may be interconnected such that in response to a temperature gradient between a first side (e.g., the hot side) and a second side (e.g., the cold side), each thermoelectric element contributes to the total energy provided by the thermoelectric energy harvester 900. A thermal contact layer 940 may be provided to support the temperature gradient between the first side and the second side. The thermal contact layer 940 may be made of a material that is a good thermal conductor or may have a layer of good thermal conductor.

[0088] As Figure 9A shown, the thermoelectric energy harvester 900 may include a vertical structure and may be formed as a single wafer. The wafer-level structure of the thermoelectric energy harvester 900 allows it to be integrated with other integrated circuit components ( Figure 9A not shown) on or adjacent to the substrate 930.

[0089] As shown, the thermoelectric elements 910A within a series may include elements of the same type of thermoelectric material (e.g., only p-type or only n-type). In response to a temperature difference between the two ends, the thermoelectric material of the thermoelectric elements 910A may be selected to produce a flow of charge carriers of different polarities from one end of the thermoelectric element to the opposite end. In a thermoelectric element 910A including p-type material, positive charge carriers flow from the hot end to the relatively cold end.

[0090] The plurality of thermoelectric elements 910A may be connected in an array configuration by connecting opposite polarity ends of adjacent thermoelectric elements 910A (i.e., the top end of one thermoelectric element 910A is connected to the bottom end of an adjacent thermoelectric element 910A). In this way, the voltages and / or currents developed across the thermoelectric elements 910A may be summed together to produce a greater aggregated voltage and / or current than that of the thermoelectric elements 910A individually. The array outputs of the thermoelectric elements 910A may be connected in parallel to provide the required energy for a particular application. Interconnections 950 and 970 may connect the thermoelectric elements 910A to adjacent thermoelectric elements 910A. Each series may include only the same type of thermoelectric material (e.g., only p-type or only n-type). However, different series of different types of thermoelectric materials (e.g., p-type series and n-type series) may be integrated together.

[0091] Although each thermoelectric element 910A can provide a small amount of energy (e.g., millivolts), an array of thermoelectric elements 910A connected together can provide a higher amount of energy to a particular application as desired. When heat is applied to one side of the thermoelectric energy collector 900, electrons in the thermoelectric element 910A with p-type material flow from the cold side to the hot side of the thermoelectric element 910A. The energy generated in each thermoelectric element 910A is combined and provided at the output of the thermoelectric energy collector 900.

[0092] Figure 9B Shows a circuit equivalent to Figure 9A the thermoelectric energy collector 900 shown in. The voltage developed across the thermoelectric element 910A is represented by Vp (for the p-type thermoelectric element 910A). The individual voltages and / or currents can be added together to provide an aggregated output voltage Vout, and in the case of a drain, the voltages are added to obtain a useful voltage that can drive a conventional low-power electronic circuit.

[0093] Figure 9A Not drawn to scale, but depicts the approximate dimensions of the collector 900 in one embodiment. The thermoelectric elements 910A can have a variety of different sizes and shapes.

[0094] The thermoelectric element 910A can be purely p-type BixSb2-xTe3 or can be purely n-type Bi2Te3-xSex. The thermal contact layer 940 can be any electrically insulating but thermally conductive layer. In one embodiment, the thermal contact layer 940 can consist of multiple layers. For example, the thermal contact layer 940 can include a thin non-conductive layer, such as an oxide or nitride, and one or more thicker top metal layers to improve heat conduction. The thermal contact layer 940 can provide insulation to the electrical interconnect layer 950 at the interface to prevent electrical short circuits in the electrical interconnect layer 950. The substrate 930 can be any semiconductor substrate with sufficient thickness to facilitate heat conduction on the bottom side. Although the configuration with the substrate 930 as the cold side and the top thermal contact layer 940 as the hot side is shown, the device can also be used with the substrate 930 as the hot side and the top thermal contact layer 940 as the cold side.

[0095] The interconnections 950 can be included on the hot and cold sides of the thermoelectric elements to connect adjacent thermoelectric elements. The thermoelectric elements can include a first interconnect coupled to a first thermoelectric element on the hot side and a second interconnect connected to a second thermoelectric element on the cold side. The interconnections 950 of the first and last thermoelectric elements 910A can be output terminals connected to other circuit elements (e.g., an external circuit, a load, or an energy storage device). The interconnections 950 and 970 can include connectors of semiconductor material or metal (e.g., gold, copper, or aluminum), or even organic electrical conductors. The interconnection 970 can be a metal via.

[0096] A barrier metal 960 may be included between the thermoelectric element 910A and the interconnect 950 to separate the semiconductor material of the thermoelectric element 910A from the metal interconnect 950 while maintaining an electrical connection between the thermoelectric element 910A and the interconnect 950. The barrier metal 960 may be included to prevent the interconnect 950 from diffusing into the semiconductor material of the thermoelectric element 910A.

[0097] Although the present invention has been described above with reference to specific embodiments, the present invention is not limited to the above embodiments and the specific configurations shown in the drawings. For example, some of the components shown may be combined with each other as one embodiment, or one component may be divided into several sub-components, or any other known or available components may be added. Those skilled in the art will understand that the present invention may be implemented in other ways without departing from the spirit and essential features of the present invention. Therefore, this embodiment is exemplary in all respects and not to be considered restrictive. The scope of the present invention is indicated by the appended claims rather than by the foregoing description, and all changes within the meaning and equivalent scope of the claims are intended to be included therein.

Claims

1. A thermoelectric collector, comprising: a pair of layers; a plurality of thermoelectric elements disposed within a space between said layers and on an inclined surface of a thermoplastic island, wherein said plurality of thermoelectric elements are inclined both in a horizontal direction and in a vertical direction; and one or more dummy structures surrounding said plurality of thermoelectric elements and formed on a thermoplastic ring to form a seal surrounding said plurality of thermoelectric elements in said horizontal direction, wherein said one or more dummy structures include electrically isolated thermoelectric elements and are formed as part of a manufacturing process for forming said plurality of thermoelectric elements, wherein said thermoelectric elements are electrically serially coupled together in alternating device types, and wherein said thermoelectric elements are coupled to two said layers at their opposite ends.

2. The thermoelectric collector according to claim 1, wherein, each thermoelectric element has a top and a bottom, wherein the top of one thermoelectric element is connected to the top of a first adjacent thermoelectric element, and the bottom of said one thermoelectric element is connected to the bottom of a second adjacent thermoelectric element.

3. The thermoelectric collector according to claim 2, wherein, said thermoelectric elements are connected by interconnections disposed on said pair of layers, and wherein said thermoelectric elements include connection portions parallel to said interconnections at one or both ends of said thermoelectric elements, and said connection portions are connected to said interconnections.

4. The thermoelectric collector according to claim 1, wherein, said thermoelectric elements include p-type thermoelectric elements and n-type thermoelectric elements connected in series and alternating between p-type and n-type thermoelectric elements simultaneously.

5. The thermoelectric collector according to claim 4, wherein, said p-type thermoelectric elements are inclined in a first direction, and the n-type thermoelectric elements are inclined in a second direction opposite to the first direction.

6. The thermoelectric collector according to claim 4, wherein, each p-type thermoelectric element is adjacent only to an n-type thermoelectric element.

7. The thermoelectric collector according to claim 1, wherein said plurality of thermoelectric elements have a conical or pyramidal shape.

8. The thermoelectric collector according to claim 1, further comprising a plurality of thermoplastic material regions disposed between adjacent thermoelectric elements.

9. The thermoelectric collector according to claim 8, wherein each of said plurality of thermoplastic material regions supports a corresponding pair of thermoelectric elements.

10. The thermoelectric collector according to claim 1, further comprising through holes and pads disposed on a first layer of said pair of layers, wherein said through holes connect said pads to a first thermoelectric element among said plurality of thermoelectric elements.

11. The thermoelectric collector according to claim 1, wherein said one or more dummy structures are inclined.

12. The thermoelectric collector according to claim 11, further comprising a thermoplastic material region disposed on a first layer of said pair of layers to support one or more inclined dummy structures.

13. A thermoelectric collector, comprising: a plurality of p-type thermoelectric elements disposed between a first heat conductor layer and a second heat conductor layer, wherein said plurality of p-type thermoelectric elements are inclined in a first direction; A plurality of n-type thermoelectric elements disposed between the first thermally conductive layer and the second thermally conductive layer, wherein the plurality of n-type thermoelectric elements are inclined in a second direction opposite to a first direction, and wherein the plurality of p-type thermoelectric elements and the plurality of n-type thermoelectric elements are formed on an inclined surface of a thermoplastic island; One or more dummy structures surrounding the plurality of p-type thermoelectric elements and the plurality of n-type thermoelectric elements and formed on a thermoplastic ring to form a seal surrounding the plurality of p-type thermoelectric elements and the plurality of n-type thermoelectric elements in a horizontal direction, Wherein the one or more dummy structures include electrically isolated p-type and n-type thermoelectric elements and are formed as part of a manufacturing process for forming the plurality of p-type thermoelectric elements and the plurality of n-type thermoelectric elements, Wherein the p-type thermoelectric elements and the n-type thermoelectric elements are connected in series and alternate simultaneously between the p-type thermoelectric elements and the n-type thermoelectric elements, and Wherein at least one of the p-type thermoelectric elements and the n-type thermoelectric elements on the inclined surface of the thermoplastic island is inclined in both a horizontal direction and a vertical direction with respect to a direction of a thermal gradient between the first thermally conductive layer and the second thermally conductive layer.

14. The thermoelectric collector according to claim 13, further comprising a plurality of thermoplastic material regions between the plurality of p-type thermoelectric elements and the plurality of n-type thermoelectric elements.

15. The thermoelectric collector according to claim 14, Wherein, The p-type thermoelectric elements and the n-type thermoelectric elements are disposed on an inclined surface of a thermoplastic.

16. The thermoelectric collector according to claim 13, Wherein, Each p-type thermoelectric element is only adjacent to an n-type thermoelectric element.

17. The thermoelectric collector according to claim 13, wherein the top of one thermoelectric element is connected to the top of a first adjacent thermoelectric element, and the bottom of the one thermoelectric element is connected to the bottom of a second adjacent thermoelectric element.

18. The thermoelectric collector according to claim 13, Wherein, One or more of the dummy structures are inclined.

19. The thermoelectric collector according to claim 13, Wherein, The p-type thermoelectric elements and the n-type thermoelectric elements are connected in series by an interconnection disposed on the first thermally conductive layer and the second thermally conductive layer, and Wherein the p-type thermoelectric elements and the n-type thermoelectric elements include connection portions parallel to the interconnection at one or both ends thereof, and the connection portions are connected to the interconnection.

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