Thermoelectric device and preparation method thereof

Abstract

The invention provides a thermoelectric device and a preparation method thereof, and relates to the technical field of thermoelectric devices, and the thermoelectric device comprises a substrate, a P-type thermoelectric arm, an N-type thermoelectric arm, a first electrode, and a second electrode. Wherein the P-type thermoelectric arm and the N-type thermoelectric arm are arranged in a hole penetrating through the substrate; the first electrode is arranged on the first surface of the substrate, the second electrode is arranged on the second surface of the substrate, and the first electrode and the second electrode are electrically connected with the P-type thermoelectric arm and the N-type thermoelectric arm; wherein the first electrode is used for conveying current from the N-type thermoelectric arm to the P-type thermoelectric arm; and the second electrode is used for conveying current from the P-type thermoelectric arm to the N-type thermoelectric arm. Based on the device, heat dissipation or refrigeration in a small-scale environment can be realized, and the problems of low heat dissipation efficiency and the like caused by low heat conductivity of the substrate are avoided.

Description

Technical Field

[0001] The present application relates to the technical field of thermoelectric devices, and more particularly, to a thermoelectric device and a method for manufacturing the same. Background Art

[0002] Currently, modern technologies represented by artificial intelligence (AI) applications have increasingly high requirements for computing power, driving the continuous development of electronic devices towards high performance, miniaturization, and other directions. Correspondingly, high performance often comes with high heat. How to quickly dissipate heat or even refrigerate in a small space to improve the performance of electronic devices has become a new problem that urgently needs to be solved. Summary of the Invention

[0003] The present application provides a thermoelectric device and a method for manufacturing the same, which can be applied to heat dissipation or refrigeration on a small scale.

[0004] In a first aspect, a thermoelectric device is provided, including: a substrate, a P-type thermoelectric arm, an N-type thermoelectric arm, a first electrode, and a second electrode; wherein, the P-type thermoelectric arm and the N-type thermoelectric arm are disposed in a hole penetrating the substrate; the first electrode is disposed on a first surface of the substrate, the second electrode is disposed on a second surface of the substrate, and the first electrode and the second electrode electrically connect the P-type thermoelectric arm and the N-type thermoelectric arm; wherein, the first electrode is used to transport current from the N-type thermoelectric arm to the P-type thermoelectric arm; the second electrode is used to transport current from the P-type thermoelectric arm to the N-type thermoelectric arm.

[0005] In combination with the first aspect, in some implementation manners of the first aspect, the thermoelectric device further includes a first insulating layer and a second insulating layer. The first insulating layer is disposed on the first surface of the substrate, and the first electrode is located between the first insulating layer and the substrate; the second insulating layer is disposed on the second surface of the substrate, and the second electrode is located between the second insulating layer and the substrate.

[0006] In combination with the first aspect, in some implementation manners of the first aspect, a transition metal layer is disposed between the first electrode and / or the second electrode and the substrate.

[0007] In combination with the first aspect, in some implementation manners of the first aspect, a bonding metal layer is disposed outside the first insulating layer or the second insulating layer.

[0008] In combination with the first aspect, in some implementation manners of the first aspect, the substrate is glass or polyimide.

[0009] In a second aspect, a method for manufacturing a thermoelectric device is provided. The thermoelectric device includes a substrate, a P-type thermoelectric arm, an N-type thermoelectric arm, a first electrode, and a second electrode. The method includes: forming a through-hole in the substrate; filling the through-hole with a thermoelectric material to form the P-type thermoelectric arm and the N-type thermoelectric arm; disposing a first electrode on a first surface of the substrate and a second electrode on a second surface of the substrate, wherein the first electrode and the second electrode electrically connect the P-type thermoelectric arm and the N-type thermoelectric arm; wherein the first electrode is configured to conduct current from the N-type thermoelectric arm to the P-type thermoelectric arm, and the second electrode is configured to conduct current from the P-type thermoelectric arm to the N-type thermoelectric arm.

[0010] In combination with the second aspect, in certain implementations of the second aspect, forming the through-hole in the substrate and filling the through-hole with the thermoelectric material includes: forming the through-hole in the substrate twice, filling the first-formed through-hole with a P-type thermoelectric material to form the P-type thermoelectric arm, and filling the second-formed through-hole with an N-type thermoelectric material to form the N-type thermoelectric arm; or forming the through-hole in the substrate twice, filling the first-formed through-hole with the N-type thermoelectric material to form the N-type thermoelectric arm, and filling the second-formed through-hole with the P-type thermoelectric material to form the P-type thermoelectric arm.

[0011] In combination with the second aspect, in certain implementations of the second aspect, forming the through-hole in the substrate and filling the through-hole with the thermoelectric material includes: forming a plurality of through-holes in the substrate; filling a first portion of the plurality of through-holes with a first type of thermoelectric material to form the P-type thermoelectric arm; and filling a second portion of the plurality of through-holes with a second type of thermoelectric material to form the N-type thermoelectric arm.

[0012] In combination with the second aspect, in certain implementations of the second aspect, the method further includes: disposing a transition metal layer on two end faces of the P-type thermoelectric arm and the N-type thermoelectric arm before disposing the first electrode on the first surface of the substrate and the second electrode on the second surface of the substrate.

[0013] In combination with the second aspect, in certain implementations of the second aspect, the method further includes: disposing a first insulating layer on the first surface of the substrate, with the first electrode being located between the first insulating layer and the substrate; and disposing a second insulating layer on the second surface of the substrate, with the second electrode being located between the second insulating layer and the substrate.

[0014] In combination with the second aspect, in certain implementations of the second aspect, the method further includes: disposing a bonding metal layer outside the first insulating layer.

[0015] In combination with the second aspect, in some implementation manners of the second aspect, the substrate is glass or polyimide. Description of the Drawings

[0016] Figure 1 is a schematic structural diagram of a thermoelectric device;

[0017] Figure 2 is a schematic structural diagram of a thermoelectric device provided by an embodiment of the present application;

[0018] Figure 3 is a schematic diagram of the current direction of an electrode in a thermoelectric device;

[0019] Figure 4 is a schematic diagram of a circuit connection manner;

[0020] Figure 5 is a schematic diagram of a circuit connection manner;

[0021] Figure 6 is a schematic diagram of a circuit connection manner;

[0022] Figure 7 is a schematic structural diagram of a thermoelectric device provided by an embodiment of the present application;

[0023] Figure 8 is a schematic flowchart of a preparation method of a thermoelectric device provided by an embodiment of the present application;

[0024] Figure 9 is a schematic diagram of a method for opening holes in a substrate and a method for filling a thermoelectric material provided by an embodiment of the present application;

[0025] Figure 10 is a schematic diagram of a method for opening holes in a substrate and a method for filling a thermoelectric material provided by an embodiment of the present application. Detailed Embodiments

[0026] Next, the technical solutions in the present application will be described with reference to the drawings.

[0027] Embodiments of the present application will present various aspects, embodiments or features around a system including multiple devices, components, modules, etc. It should be understood and clear that each system may include additional devices, components, modules, etc., and / or may not include all the devices, components, modules, etc. discussed in conjunction with the drawings. In addition, combinations of these solutions may also be used.

[0028] In addition, in the embodiments of the present application, words such as "exemplary" and "for example" are used to represent examples, illustrations, or explanations. Any embodiment or design described as "exemplary" in the embodiments of the present application should not be construed as being more preferred or having more advantages than other embodiments or designs. Rather, the use of the word "exemplary" is intended to present concepts in a specific manner.

[0029] The business scenarios described in the embodiments of the present application are for more clearly illustrating the technical solutions of the embodiments of the present application, and do not constitute a limitation on the technical solutions provided by the embodiments of the present application. Those of ordinary skill in the art will know that with the evolution of technology and the emergence of new business scenarios, the technical solutions provided by the embodiments of the present application are equally applicable to similar technical problems.

[0030] The reference to "one embodiment" or "some embodiments" etc. described in this specification means that in one or more embodiments of the present application, specific features, structures, or characteristics described in connection with that embodiment are included. Thus, the statements "in one embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments", etc. that appear in different places in this specification are not necessarily all referring to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in another way. The terms "comprising", "including", "having" and their variants all mean "including but not limited to", unless otherwise specifically emphasized in another way.

[0031] In the embodiments of the present application, "at least one" means one or more, and "a plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B may represent: including the case where A exists alone, the case where A and B exist simultaneously, and the case where B exists alone, where A and B may be singular or plural. The character " / " generally represents an "or" relationship between the associated objects before and after. "At least one (item)" or similar expressions thereof refer to any combination of these items, including any combination of single item (s) or plural items (s). For example, at least one (item) of a, b, or c may represent: a, b, c, a - b, a - c, b - c, or a - b - c, where a, b, c may be single or multiple.

[0032] In the description of the embodiments of the present application, the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "inner", "outer", "vertical", "horizontal", etc. is defined relative to the orientation or position in which the components in the drawings are schematically placed. It should be understood that these directional terms are relative concepts, which are used for relative description and clarification, rather than indicating or implying that the device or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. It can change accordingly with the change of the orientation in which the components in the drawings are placed. Therefore, it should not be construed as a limitation to the present application.

[0033] In the embodiments of the present application, the same reference numeral is used to represent the same component or the same part. For the same parts in the embodiments of the present application, only one of the parts or components may be marked with a reference numeral in the figure. It should be understood that the reference numeral is also applicable to other identical parts or components. In addition, the parts in the drawings are not drawn to scale, and the dimensions and sizes of the parts shown in the drawings are only exemplary and should not be construed as a limitation to the present application.

[0034] The Peltier effect is a type of thermoelectric effect. When an electric current passes through the junction of two different conductors (or semiconductors), heat absorption or heat release occurs at the junction, forming a cold end and a hot end. Its essence is that carriers (electrons or holes) exchange energy due to the chemical potential difference at the material interface. Specifically, when carriers (electrons or holes) enter a material with a high chemical potential from a material with a low chemical potential, they need to absorb heat from the environment to maintain energy conservation; when carriers enter a material with a low chemical potential from a material with a high chemical potential, the excess energy is released in the form of heat. This phenomenon can achieve precise temperature control without mechanical components and is widely used in micro-refrigeration, electronic heat dissipation, and medical equipment.

[0035] Figure 1 It is a schematic diagram of a thermoelectric device that can be used for heat dissipation or refrigeration. Among them, the thermoelectric device includes a cold-end contact layer 201 in contact with the object to be cooled, a hot-end contact layer 202 in contact with the radiator, current guiding fins 101 - 105, P-type thermoelectric arms P1 and P2, and N-type thermoelectric arms N1 and N2. Among them, the P-type thermoelectric arms and N-type thermoelectric arms are thermoelectric arms made of thermoelectric materials. The P-type thermoelectric arms generally have holes (positive charges) as the main carriers. Under the temperature difference, the holes diffuse from the high-temperature end to the low-temperature end, forming a current direction consistent with the heat flow direction; the N-type thermoelectric arms generally have electrons (negative charges) as the main carriers, and the electrons diffuse from the high-temperature end to the low-temperature end, and the current direction is opposite to the heat flow direction. The P-type thermoelectric arms and N-type thermoelectric arms can be collectively referred to as thermocouple pairs.

[0036] Specifically, as Figure 1As shown, when current flows into the P-type thermoelectric arm P1 from the current guiding piece 101 and then into the N-type heat conducting arm N1 through the current guiding piece 102. According to the Peltier effect, when current enters the P-type thermoelectric arm P1 from the N-type thermoelectric arm N1, electrons transition to higher energy levels. As a result, the junction between the N-type thermoelectric arm N1 and the P-type thermoelectric arm P1 (i.e., the current guiding piece 102) absorbs heat and becomes the cold end; when current enters the N-type thermoelectric arm N2 from the P-type thermoelectric arm P1, electrons transition to lower energy levels. As a result, the junction between the P-type thermoelectric arm P1 and the N-type thermoelectric arm N2 (i.e., the current guiding piece 103) releases heat and becomes the hot end; similarly, the current guiding piece 104 also absorbs heat and becomes the cold end. Among them, the current guiding pieces 102 to 104 can also be referred to as electrodes. The current guiding piece 102 and the current guiding piece 104 can become cold end electrodes, and the current guiding piece 103 can be referred to as the hot end electrode.

[0037] Among them, semiconductor heat dissipation and refrigeration devices made of thermoelectric materials represented by bismuth telluride (Bi2Te3) are considered to be superior materials for making P-type and N-type thermoelectric arms due to their advantages such as small volume, all-solid state, no noise, and no pollution. The general method for making thermoelectric arms using Bi2Te3 as the material is to first form large-area blocks of P-type and N-type through high-temperature sintering, and then use physical cutting to make P / N-type thermoelectric arm particles. It should be understood that the thermoelectric material used to prepare the thermoelectric arms in the embodiments of the present application can also be other thermoelectric materials, and the present application does not make any limitations in this regard.

[0038] Among them, the cold end contact layer 201 or the hot end contact layer 202 can be made of ceramic chips. The ceramic chips are high-thermal-conductivity support materials, such as ceramics made of aluminum nitride (AlN). It should be understood that the cold end contact layer 201 or the hot end contact layer 202 in the embodiments of the present application can also be other materials with strong thermal conductivity, and the present application does not make any limitations in this regard.

[0039] Currently, the preparation of the above-mentioned thermoelectric devices is mainly completed on a silicon (Si) substrate, that is, thermoelectric arms can be prepared on the Si substrate. For example, through thin-film processing techniques (such as magnetron sputtering, evaporation, chemical vapor deposition, electroplating, etc.), combined with patterning techniques (such as the lift-off method of semiconductor lithography), a thermoelectric arm array with a width of several hundred micrometers (um) and a thickness of less than 20 um can be fabricated on a small-area Si substrate. However, all such methods use Si as the substrate, and the Si-based semiconductor process is at the nanometer (nm) level, while the above-mentioned thermoelectric devices only require an accuracy of um level to meet the requirements, resulting in redundant process complexity. In addition, the thermal conductivity of Si is relatively low, which is not conducive to the longitudinal transmission of heat, hinders the efficient heat conduction between the cold / hot ends, reduces the device performance, and moreover, the price of the Si substrate is relatively high, thus resulting in a high cost for fabricating thermoelectric devices. In addition, when fabricating thermoelectric devices on a Si substrate, it is usually necessary to use photoresist to define patterns through photochemical reactions to guide subsequent material deposition or etching. The photoresist itself is not resistant to high temperatures and is prone to carbonization and release of impurities at high temperatures, contaminating the thermoelectric material and reducing the conductivity.

[0040] In summary, the thermoelectric devices prepared using Si as the substrate have problems such as redundant process complexity, high cost, and poor thermal conductivity.

[0041] This application provides a thermoelectric device and a method for preparing the same. The substrate is used as an intermediate support material between the cold end and the hot end, and holes are formed in the substrate to fill with thermoelectric materials to form thermoelectric arms. Electrodes are fabricated on both sides of the substrate for electrical interconnection of P-type thermoelectric arms and N-type thermoelectric arms, thus eliminating the need for an additional Si substrate and effectively solving the problems brought by the Si substrate.

[0042] Figure 2 It is a schematic structural diagram of a thermoelectric device proposed in an embodiment of this application.

[0043] Refer to Figure 2 , the thermoelectric device includes a substrate 10, P-type thermoelectric arms P1 and P2, N-type thermoelectric arms N1 and N2, first electrodes 102 and 104, and a second electrode 103.

[0044] Among them, the P-type thermoelectric arms and N-type thermoelectric arms are disposed in holes (hereinafter simply referred to as through-holes) penetrating the substrate 10. The first electrodes are disposed on the first surface of the substrate, and the second electrodes are disposed on the second surface of the substrate. The first electrodes and the second electrodes are electrically connected to the P-type thermoelectric arms and the N-type thermoelectric arms.

[0045] Among them, the first electrode is used to convey current from the N-type thermoelectric arm to the P-type thermoelectric arm; the second electrode is used to convey current from the P-type thermoelectric arm to the N-type thermoelectric arm.

[0046] It should be understood that the through-holes and the thermoelectric arms correspond one by one. For example, the P-type thermoelectric arm P1 is disposed in through-hole 1, the P-type thermoelectric arm P2 is disposed in through-hole 2, the N-type thermoelectric arm N1 is disposed in through-hole 3, and the N-type thermoelectric arm N2 is disposed in through-hole 4.

[0047] In some implementation manners, the thermoelectric device further includes other thermoelectric arms and corresponding through-holes, that is, it further includes at least one P-type thermoelectric arm and / or at least one N-type thermoelectric arm, and each thermoelectric arm is disposed in a corresponding through-hole one by one.

[0048] It should be understood that for the first electrode 102, current flows through the first electrode 102 from the N-type thermoelectric arm N1 to the P-type thermoelectric arm P1, and the first electrode 102 absorbs heat. Similarly, for the first electrode 104, current flows through the first electrode 104 from the N-type thermoelectric arm N2 to the P-type thermoelectric arm P2, and the first electrode 104 absorbs heat. For the second electrode 103, current flows through the second electrode 103 from the P-type thermoelectric arm P1 to the N-type thermoelectric arm N2, and the second electrode 103 releases heat. After this process, the first electrodes 102 and 104 that absorb heat are called the cold ends, and can also be called the cold-end electrodes; the second electrode 103 that releases heat becomes the hot end, and can also be called the hot-end electrode.

[0049] It should be understood that the surface of the substrate 10 where the first electrode is disposed (i.e., the first surface) can also be called the cold surface, and the surface where the second electrode is disposed (i.e., the second surface) can also be called the hot surface.

[0050] In some implementation manners, the above-mentioned P-type thermoelectric arm or N-type thermoelectric arm is a thermoelectric arm made of Bi2Te3-based material. For example, the P-type thermoelectric arm and the N-type thermoelectric arm are respectively made by doping different materials in Bi2Te3, and the present application does not limit this. For example, the P-type thermoelectric arm can be doped with Sb in Te vacancies, and the N-type thermoelectric arm can be doped with Se or I in Te vacancies.

[0051] In other implementation manners, the P-type thermoelectric arm or the N-type thermoelectric arm can also be made of PbTe-based material, CoSb3-based material, Mg3Sb2-based material, Half-Heusler alloy or other materials, and the present application does not limit this. It should be understood that the composition of the P-type thermoelectric arm or the N-type thermoelectric arm can refer to the prior art and will not be elaborated here.

[0052] In some implementation manners, the substrate 10 is glass, polyimide PI or other insulating materials, and the present application does not limit this.

[0053] It should be understood that for the thermoelectric device provided in the present application, heat exchange is carried out through the Peltier effect, and the substrate does not participate in the main heat exchange. Therefore, although the thermal conductivity of glass or PI is low, it has no influence on the heat dissipation or refrigeration performance of the thermoelectric device of the present application. Among them, glass has the advantages of high heat resistance and low cost, and is suitable for high-temperature rigid devices; PI is known for its excellent flexibility, wide temperature stability and low coefficient of thermal expansion. Although the cost is higher than that of glass, it is still much lower than the Si substrate and can be adapted to flexible devices. When actually selecting the substrate, factors such as temperature resistance requirements, mechanical properties and cost need to be weighed.

[0054] For the above-mentioned thermoelectric device, such as Figure 3As shown, the electrode on the first surface of the substrate (i.e., the first electrode) should satisfy that the current is transported from the N-type thermoelectric arm to the P-type thermoelectric arm, and the electrode on the second surface of the substrate (i.e., the second electrode) should satisfy that the current is transported from the P-type thermoelectric arm to the N-type thermoelectric arm, so as to ensure that the first surface of the substrate is the cold surface and the second surface of the substrate is the hot surface. Regarding the connection method of the circuit in the thermoelectric device, the present application does not make any limitation, as long as the above requirements can be met.

[0055] Exemplarily, two specific circuit connection methods will be introduced below in conjunction with Figure 4 and Figure 5 introduce two specific circuit connection methods.

[0056] Referring to Figure 4 or Figure 5 , Figure 4 and Figure 5 are circuit structures shown under the condition of observing the first surface of the substrate. Among them, the blue bars represent the electrodes on the first surface of the substrate (i.e., the first electrodes), and the orange bars represent the electrodes on the second surface of the substrate (i.e., the second electrodes). Figure 4 or Figure 5 The circuit connection methods shown can all satisfy that the current is transported from the N-type thermoelectric arm to the P-type thermoelectric arm on the first electrode and from the P-type thermoelectric arm to the N-type thermoelectric arm on the second electrode.

[0057] It should be understood that on the two surfaces of the substrate, the electrodes serve as the refrigeration and heat dissipation areas. In order to improve the heat conduction efficiency, the size of the electrodes can be made relatively large. Taking Figure 5 the circuit connection method shown as an example, increasing the width of the electrode can obtain Figure 6 the circuit connection method in where the width of the electrode can be equivalent to or larger than the width of the thermoelectric arm. The present application does not make any limitation in this regard.

[0058] In some implementation manners, in order to achieve electrical insulation (to avoid leakage or short circuit) while ensuring efficient heat transfer, the two surfaces of the thermoelectric device may further include a first insulating layer 201 and a second insulating layer 202. Referring to Figure 7 , the first insulating layer 201 is located on the first surface of the substrate and can also be called the cold-end contact layer, which can be directly in contact with the object to be cooled; the second insulating layer 202 can also be called the hot-end contact layer, which can be directly in contact with the radiator.

[0059] It should be understood that the first insulating layer 201 or the second insulating layer 202 is made of a material with good insulation and heat conduction performance, such as AlN, aluminum oxide (Al2O3), boron nitride (BN), thermal conductive grease / silicone, etc. The present application does not make any limitation on the specific material.

[0060] In some implementation manners, the outer contact surface of the first insulating layer or the second insulating layer can be roughened. For example, the interface adhesion can be enhanced by plasma etching or laser treatment.

[0061] In some implementations, referring to Figure 7 , a transition metal layer is further included between the electrodes and the thermoelectric arms of the thermoelectric device. This transition metal layer can reduce the contact resistance between the electrodes and the thermoelectric arms, increase the conductivity, and can also increase the connection adhesion and stability between the thermoelectric arms and the electrodes.

[0062] For example, the transition metal layer can be made of metal materials such as nickel (Ni), titanium (Ti), molybdenum (Mo), chromium (Cr), etc., and the present application does not limit this.

[0063] In addition, referring to Figure 7 , in some implementations, a bonding metal layer 301 may be further included outside the first insulating layer 201 of the thermoelectric device. This bonding metal layer 301 is used to couple with the object to be cooled, increasing the connection stability.

[0064] It should be understood that the selection of the bonding metal directly affects the heat conduction efficiency, electrical connection reliability, and long-term stability. The material of this bonding metal layer needs to meet the following requirements: high thermal conductivity to ensure efficient heat transfer (for example, promoting heat dissipation of the silicon chip or heat absorption of the thermoelectric device); low contact resistance to reduce Joule heat loss; matching thermal expansion coefficient, the thermal expansion coefficient of the bonding metal layer needs to be coordinated with the object to be cooled; relatively high mechanical strength to be able to resist thermal cycling stress.

[0065] Optionally, the bonding metal layer 301 can be made of materials such as metal (Cu), tin (Sn), gold (Au), silver (Ag), etc., and the present application does not limit this.

[0066] Through the above thermoelectric device, heat dissipation or refrigeration in a small-scale environment can be achieved. And since the substrate does not participate in the heat exchange process and only serves as a support material between the hot and cold ends, problems such as low heat dissipation efficiency caused by low thermal conductivity of the substrate can be avoided, and using glass or PI as the substrate, the cost is relatively low.

[0067] As Figure 8 shown, the present application also provides a preparation method of a thermoelectric device. Through this method, the above thermoelectric device can be prepared. The description of the relevant components in the thermoelectric device can refer to the above content and will not be elaborated here.

[0068] This method includes:

[0069] S1001, opening through holes in the substrate; S1002, filling thermoelectric materials in the through holes to form P-type thermoelectric arms and N-type thermoelectric arms.

[0070] Among them, this step can be implemented in two ways. Among them, Method 1 is to open holes in two times, and different thermoelectric materials are filled after each hole opening; Method 2 is to open holes once, and P-type thermoelectric materials and N-type thermoelectric materials are respectively filled in different through holes opened. These two methods are introduced in detail below.

[0071] Method 1

[0072] In one implementation, referring to Figure 9 , the first hole is opened on the substrate, and P-type thermoelectric material is filled in the through hole opened for the first time to form a P-type thermoelectric arm; after the through hole is etched and polished, the second hole is opened on the substrate, and N-type thermoelectric material is filled in the through hole opened for the second time to form an N-type thermoelectric arm.

[0073] Similarly, in another implementation, the first hole is opened on the substrate, and N-type thermoelectric material is filled in the through hole opened for the first time to form an N-type thermoelectric arm; after the through hole is etched and polished, the second hole is opened on the substrate, and P-type thermoelectric material is filled in the through hole opened for the second time to form a P-type thermoelectric arm.

[0074] Specifically, according to the different materials of the substrate, the ways of opening holes on the substrate can also be different.

[0075] For example, if the substrate is glass, the hole opening process can include: 1) Laser-induced etching, that is, using the high energy density of femtosecond laser or ultrafast pulsed laser to ablate layer by layer on the glass through photothermal or photochemical action to form through holes, for the aperture in the range of 10um - 100um; 2) Hard mask hydrofluoric acid (HF) etching, that is, using HF or buffered etchant (BOE) to etch the glass isotropically, and combining photoresist or metal mask to control the hole opening area, for the aperture above 100um.

[0076] It should be understood that the glass substrate generally has a thickness of more than 0.5mm. When manufacturing the thermoelectric device in this application, the thinning process can be used as needed, and generally the minimum can be thinned to 100um.

[0077] Also for example, if the substrate is PI, the hole opening process can include: 1) Laser drilling, that is, using ultraviolet laser or CO2 laser to ablate the PI substrate to form through holes; 2) Photolithography + chemical etching, that is, coating photoresist on the PI surface, defining the through hole pattern through exposure and development, and using chemical etchant (such as strong alkaline solution) to selectively remove the PI material to form through holes; 3) Plasma etching, through reactive ion etching or deep reactive ion etching technology, using plasma (such as O2 / CF4 mixed gas) to bombard the PI surface to form through holes.

[0078] Exemplarily, after the opening is completed, the way to fill the thermoelectric material can be the thin film filling method, such as electroplating method, etc., which is not limited in this application.

[0079] For example, first prepare a seed layer in the opened through holes by magnetron sputtering, and then fill the P-type or N-type material by electroplating. Among them, magnetron sputtering is a physical vapor deposition technology, which is usually used to deposit thin film materials on the surface of a substrate; the seed layer refers to a thin film that serves as a substrate in subsequent electroplating or deposition processes, and is used to promote better adhesion and uniformity.

[0080] Method 2

[0081] Open a plurality of through holes for filling thermoelectric materials on the substrate, that is, open all the through holes at one time, and then fill the P-type thermoelectric material in some of the through holes among the plurality of through holes to form a P-type thermoelectric arm; fill the N-type thermoelectric material in another part of the through holes among the plurality of through holes to form an N-type thermoelectric arm. The following specifically introduces this process.

[0082] In one implementation, refer to Figure 10 , open all the through holes on the substrate at one time, and completely fill the opened through holes with photoresist or other organic materials, then use a photomask and exposure to selectively remove the filling materials in some areas, expose some target holes, and fill the N-type thermoelectric material in these part of the target holes to form an N-type thermoelectric arm; then remove the remaining filling materials, etch and polish the through holes, and fill the P-type thermoelectric material to form a P-type thermoelectric arm.

[0083] Similarly, in another implementation, refer to Figure 10 , open all the through holes on the substrate at one time, and completely fill the opened through holes with photoresist or other organic materials, then use a photomask and exposure to selectively remove the filling materials in some areas, expose some target holes, and fill the P-type thermoelectric material in these part of the target holes to form a P-type thermoelectric arm; then remove the remaining filling materials, etch and polish the through holes, and fill the N-type thermoelectric material to form an N-type thermoelectric arm.

[0084] Among them, the way to open holes on the substrate and the way to fill the thermoelectric material can refer to the description in Method 1.

[0085] S1003, set a first electrode on the first side of the substrate and a second electrode on the second side of the substrate.

[0086] Specifically, make connecting metal electrodes on both sides of the substrate. The main requirements for the connecting electrodes are high electrical conductivity and thermal conductivity. Among them, regarding the connection method between the electrodes and the thermoelectric arms, reference can be made to the introduction of the above thermoelectric devices, which will not be elaborated here.

[0087] Exemplarily, the electrode can be prepared in the following ways, such as physical vapor deposition, electroplating, screen printing, thermocompression welding, etc.

[0088] Among them, the electrode can adopt materials with strong electrical conductivity and a coefficient of thermal expansion close to that of the thermoelectric material. For example, Ni, Cu, Au, alloys, multi-layer metals, etc. This application does not limit this.

[0089] In some implementation manners, in order to increase the electrical conductivity, connection adhesion, and stability between the thermoelectric arm and the connecting electrode, as Figure 7 shown, a transition metal layer can be fabricated between the electrode and the thermoelectric arm. Among them, the material of the transition metal layer has a high electrical conductivity and a low thermal conductivity.

[0090] Among them, the processing method of the transition metal layer can be selected according to the precision requirements, such as sputtering process, electroplating process, screen printing, etc. This application does not limit this.

[0091] S1004 (optional step), a first insulating layer is provided on the first surface of the substrate; a second insulating layer is provided on the second surface of the substrate.

[0092] Among them, the introduction of the first insulating layer and the second insulating layer can refer to the introduction of the thermoelectric device, and will not be elaborated here.

[0093] It should be understood that after the basic structure of the thermoelectric device is completed, the thermoelectric device can be encapsulated through the insulating layer, and the encapsulation material is a material with high insulation and high thermal conductivity.

[0094] For example, relatively thick AlN ceramic substrates can be attached to both sides of the thermoelectric device, and a thin film can be directly fabricated using the AlN thin film fabrication process, such as the PVD process. In addition, the first insulating layer and the second insulating layer can also be other materials, which are not limited in this application.

[0095] In certain implementation manners, a bonding metal layer can also be provided outside the first insulating layer or the second insulating layer for bonding with the object to be cooled.

[0096] Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in combination with the embodiments disclosed herein can be implemented by electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. Professional technicians can use different methods for each specific application to implement the described functions, but such implementation should not be considered to exceed the scope of this application.

[0097] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, devices, and units described above can refer to the corresponding processes in the foregoing method embodiments and will not be elaborated herein.

[0098] In several embodiments provided in the present application, it should be understood that the disclosed systems, devices, and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there can be other division methods in actual implementation. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces, and the indirect couplings or communication connections of the devices or units can be in electrical, mechanical, or other forms.

[0099] The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0100] In addition, in each embodiment of the present application, the functional units can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit.

[0101] If the function is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art or a part of this technical solution can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in each embodiment of the present application. The foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs that can store program codes.

[0102] As described above, it is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present application can easily think of changes or substitutions, which should all be covered within the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claimed rights.

Claims

1. A thermoelectric device, characterized in that: include: A substrate, a P-type thermoelectric arm, an N-type thermoelectric arm, a first electrode, and a second electrode; wherein, The P-type thermoelectric arm and the N-type thermoelectric arm are arranged in a hole penetrating the substrate; The first electrode is disposed on the first surface of the substrate, the second electrode is disposed on the second surface of the substrate, and the first electrode and the second electrode are electrically connected to the P-type thermoelectric arm and the N-type thermoelectric arm; The first electrode is used to transport current from the N-type thermoelectric arm to the P-type thermoelectric arm; and the second electrode is used to transport current from the P-type thermoelectric arm to the N-type thermoelectric arm.

2. The thermoelectric device according to claim 1, characterized in that The thermoelectric device further comprises a first insulating layer and a second insulating layer, The first insulating layer is disposed on the first surface of the substrate, and the first electrode is located between the first insulating layer and the substrate; The second insulating layer is disposed on the second surface of the substrate, and the second electrode is located between the second insulating layer and the substrate.

3. The thermoelectric device according to claim 1 or 2, characterized in that: A transition metal layer is disposed between the first electrode and / or the second electrode and the substrate.

4. The thermoelectric device according to claim 2, characterized in that A bonding metal layer is arranged outside the first insulating layer or the second insulating layer.

5. The thermoelectric device according to any one of claims 1 to 4, characterized in that The substrate is glass or polyimide.

6. A method for preparing a thermoelectric device, characterized in that: The thermoelectric device comprises a substrate, a P-type thermoelectric arm, an N-type thermoelectric arm, a first electrode, and a second electrode, and the method comprises: Opening a through hole on the substrate; Filling the through hole with thermoelectric material to form the P-type thermoelectric arm and the N-type thermoelectric arm; A first electrode is disposed on the first surface of the substrate, and a second electrode is disposed on the second surface of the substrate, wherein the first electrode and the second electrode are electrically connected to the P-type thermoelectric arm and the N-type thermoelectric arm; The first electrode is used to transport current from the N-type thermoelectric arm to the P-type thermoelectric arm, and the second electrode is used to transport current from the P-type thermoelectric arm to the N-type thermoelectric arm.

7. The method according to claim 6, characterized in that The step of opening a through hole on the substrate and filling the through hole with a thermoelectric material comprises: Opening through holes twice on the substrate, and filling the through holes opened for the first time with P-type thermoelectric material to form the P-type thermoelectric arm, and filling the through holes opened for the second time with N-type thermoelectric material to form the N-type thermoelectric arm; or, Through holes are opened twice on the substrate, and the N-type thermoelectric material is filled in the first through hole to form the N-type thermoelectric arm, and the P-type thermoelectric material is filled in the second through hole to form the P-type thermoelectric arm.

8. The method according to claim 6, characterized in that The step of opening a through hole on the substrate and filling the through hole with a thermoelectric material comprises: Opening a plurality of through holes on the substrate; Filling a P-type thermoelectric material in some of the plurality of through holes to form the P-type thermoelectric arm; Another part of the plurality of through holes is filled with N-type thermoelectric material to form the N-type thermoelectric arm.

9. The method according to any one of claims 6 to 8, characterized in that The method further comprises: Before arranging the first electrode on the first surface of the substrate and the second electrode on the second surface of the substrate, a transition metal layer is arranged on both end surfaces of the P-type thermoelectric arm and the N-type thermoelectric arm.

10. The method according to any one of claims 6 to 9, characterized in that The method further comprises: A first insulating layer is disposed on the first surface of the substrate, and the first electrode is located between the first insulating layer and the substrate; A second insulating layer is disposed on the second surface of the substrate, and the second electrode is located between the second insulating layer and the substrate.

11. The method according to claim 10, characterized in that The method further comprises: A bonding metal layer is arranged outside the first insulating layer or the second insulating layer.

12. The method according to any one of claims 6 to 11, characterized in that The substrate is glass or polyimide.

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