A packaging structure of a bismuth telluride-based thermoelectric device and a preparation method thereof

Abstract

The present invention discloses a packaging structure for a bismuth telluride-based thermoelectric device and a preparation method thereof, belonging to the field of thermoelectric technology, and aims to provide a packaging structure for an n-type bismuth telluride thermoelectric device with strong adhesion, good barrier properties, low resistivity, and good solder wettability, and a preparation method thereof. The packaging structure comprises a buffer layer, a barrier layer, and an electrode layer. The buffer layer is made of a conductive semiconductor oxide, the barrier layer is made of a metal or a metal alloy, and the electrode layer is made of a metal or a metal alloy. By introducing a conductive semiconductor oxide as a buffer layer into the bismuth telluride matrix, it can effectively prevent the metal ions in the barrier layer from forming a solid solution with the bismuth telluride matrix, thereby increasing the bonding strength between the bismuth telluride matrix and the packaging layer. The present invention is applicable to a packaging structure for a bismuth telluride-based thermoelectric device and a preparation method thereof.

Description

Technical Field

[0001] The present invention belongs to the field of thermoelectric technology, and in particular relates to a packaging structure of a bismuth telluride-based thermoelectric device and a preparation method thereof. Background Art

[0002] Thermoelectric materials are a new energy material that can realize the mutual conversion of thermal energy and electrical energy. Thermoelectric generators made of thermoelectric materials can be used for temperature difference power generation and thermoelectric refrigeration. The connection interface between thermoelectric materials and electrodes is an important part of thermoelectric devices, which directly affects the reliability and life of the devices.

[0003] Based on the experience of thermoelectric device preparation and application, the ideal barrier layer properties include the following:

[0004] (1) The barrier layer material must have high electrical conductivity and thermal conductivity to minimize the total resistance and total thermal resistance of the entire device and ensure that energy is not lost excessively during transmission;

[0005] (2) The coefficient of thermal expansion (CTE) of the barrier layer material should match that of the thermoelectric substrate material as much as possible, so that microcracks and holes will not be generated at the interface due to excessive thermal stress, affecting the thermoelectric transmission performance;

[0006] (3) The barrier layer material should be as thin as possible to reduce the total contact resistance and thermal resistance;

[0007] (4) The barrier layer material should have good chemical stability and be not easily changed to ensure the life of the device;

[0008] (5) The barrier layer material cannot undergo severe diffusion reaction with the thermoelectric material;

[0009] (6) The interface between the barrier layer material and the thermoelectric substrate material must have a certain mechanical strength, and no structural changes will occur at a certain operating temperature. The bonding (adhesion) strength between the interfaces should be as high as >10 MPa to ensure the mechanical stability between the interfaces of the thermoelectric device.

[0010] Traditional commercial bismuth telluride-based thermoelectric devices mainly use metals or alloys such as Ni, Cu, and Co to make barrier layers or electrodes through thermal spraying, sintering, magnetron sputtering, electroplating, etc.; the ion barrier layer of the metal or alloy prepared by magnetron sputtering and electroplating has a low resistivity, but its adhesion strength is about 8-10 MPa, and it is prone to cracking in a thermal cycling environment; the ion barrier layer of the metal or alloy prepared by thermal spraying and sintering has an adhesion strength of about 20-30 MPa, but its resistivity is relatively high.

[0011] In addition, Ni diffuses deeper in n-type Bi2Te3 than in p-type, reaching 3 μm and 100 nm respectively. The contact resistivities of Ni / p-Bi2Te3 and Ni / n-Bi2Te3 are 0.3~1.1 and 0.7~1.2 μΩ·cm respectively. 2 .

[0012] Therefore, designing and developing a packaging structure and preparation method that has strong adhesion, good barrier properties, low resistivity, good solder wettability, and is suitable for n-type Bi2Te3 can effectively improve the stability and reliability of the device. Summary of the Invention

[0013] The purpose of the present invention is to overcome the deficiencies of the prior art and provide a packaging structure of an n-type bismuth telluride thermoelectric device with strong adhesion, good barrier properties, low resistivity, and good solder wettability, and a preparation method thereof.

[0014] The technical solution adopted in the present invention is as follows:

[0015] A packaging structure for a bismuth telluride-based thermoelectric device comprises a buffer layer, a barrier layer, and an electrode layer sequentially arranged on an n-type bismuth telluride material substrate. The buffer layer is made of a conductive semiconductor oxide, the barrier layer is made of a metal or a metal alloy, and the electrode layer is made of a metal or a metal alloy.

[0016] Furthermore, the conductive semiconductor oxide is one or more combinations of indium tin oxide, indium oxide, zinc oxide, and tin oxide, and the thickness of the buffer layer is 1-5 μm.

[0017] Furthermore, the barrier layer is an alloy of one or more combinations of Ni, Cu, and Mo, and the thickness of the barrier layer is 2-10 μm.

[0018] Furthermore, the electrode layer is copper foil, and the thickness of the electrode layer is 5um-50um.

[0019] A method for preparing a packaging structure of a bismuth telluride-based thermoelectric device comprises the following steps:

[0020] (1) polishing the n-type bismuth telluride material substrate and placing it in a solution containing an ultrasonic degreasing agent for ultrasonic degreasing cleaning;

[0021] (2) Using magnetron sputtering to deposit a conductive semiconductor oxide film on an n-type bismuth telluride material substrate;

[0022] (3) Depositing a barrier layer on a conductive semiconductor oxide film using a laser cladding process;

[0023] (4) Welding the copper foil to the barrier layer using ultrasonic welding;

[0024] (5) Cut the bismuth telluride into pellets for later use.

[0025] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0026] 1. In the present invention, by introducing a conductive semiconductor oxide as a buffer layer into the bismuth telluride matrix, the metal ions of the barrier layer can be effectively prevented from forming a solid solution with the bismuth telluride matrix, thereby increasing the bonding strength between the bismuth telluride matrix and the encapsulation layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and should not be considered as limiting the scope. A person of ordinary skill in the art can also derive other relevant drawings based on these drawings without inventive effort, among which:

[0028] Figure 1 It is a front view of the present invention;

[0029] Markings in the figure: 1-buffer layer, 2-barrier layer, 3-electrode layer, 4-n-type bismuth telluride material matrix. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0031] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are intended to fall within the scope of protection of the present invention.

[0032] It should be noted that reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not require further definition or explanation in subsequent drawings.

[0033] In the description of the present invention, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" and the like indicate positions or locations based on the positions shown in the accompanying drawings, or the positions or locations in which the inventive product is typically placed when in use. These terms are intended merely to simplify the description of the present invention and do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third," etc., are used solely to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0034] Furthermore, terms such as "horizontal" and "vertical" do not necessarily mean that a component must be absolutely horizontal or overhanging, but rather that it can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal than "vertical," and does not mean that the structure must be completely horizontal, but rather that it can be slightly tilted.

[0035] In the description of the present invention, it should also be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood broadly. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention.

[0036] A packaging structure for a bismuth telluride-based thermoelectric device comprises a buffer layer, a barrier layer, and an electrode layer sequentially arranged on an n-type bismuth telluride material substrate. The buffer layer is made of a conductive semiconductor oxide, the barrier layer is made of a metal or a metal alloy, and the electrode layer is made of a metal or a metal alloy.

[0037] Furthermore, the conductive semiconductor oxide is one or more combinations of indium tin oxide, indium oxide, zinc oxide, and tin oxide, and the thickness of the buffer layer is 1-5 μm.

[0038] Furthermore, the barrier layer is an alloy of one or more combinations of Ni, Cu, and Mo, and the thickness of the barrier layer is 2-10 μm;

[0039] Furthermore, the electrode layer is copper foil, and the thickness of the electrode layer is 5um-50um.

[0040] A method for preparing a packaging structure of a bismuth telluride-based thermoelectric device comprises the following steps:

[0041] (1) polishing the n-type bismuth telluride material substrate and placing it in a solution containing an ultrasonic degreasing agent for ultrasonic degreasing cleaning;

[0042] (2) Using magnetron sputtering to deposit a conductive semiconductor oxide film on an n-type bismuth telluride material substrate;

[0043] (3) Depositing a barrier layer on a conductive semiconductor oxide film using a laser cladding process;

[0044] (4) Welding the copper foil to the barrier layer using ultrasonic welding;

[0045] (5) Cut the bismuth telluride into pellets for later use.

[0046] During the implementation of the present invention, by introducing a conductive semiconductor oxide as a buffer layer into the bismuth telluride matrix, the barrier layer metal ions can be effectively prevented from forming a solid solution with the bismuth telluride matrix, thereby increasing the bonding strength between the bismuth telluride matrix and the encapsulation layer.

[0047] Example 1

[0048] A packaging structure for a bismuth telluride-based thermoelectric device comprises a buffer layer, a barrier layer, and an electrode layer sequentially arranged on an n-type bismuth telluride material substrate. The buffer layer is made of a conductive semiconductor oxide, the barrier layer is made of a metal or a metal alloy, and the electrode layer is made of a metal or a metal alloy.

[0049] Example 2

[0050] Based on Example 1, the conductive semiconductor oxide is one or more combinations of indium tin oxide, indium oxide, zinc oxide, and tin oxide, and the thickness of the buffer layer is 1-5 μm.

[0051] Example 3

[0052] Based on the above embodiment, the barrier layer is an alloy of one or more combinations of Ni, Cu, and Mo, and the thickness of the barrier layer is 2-10 μm.

[0053] Example 4

[0054] Based on the above embodiment, the electrode layer is copper foil, and the thickness of the electrode layer is 5um-50um.

[0055] Example 5

[0056] A method for preparing a packaging structure of a bismuth telluride-based thermoelectric device comprises the following steps:

[0057] (1) polishing the n-type bismuth telluride material substrate and placing it in a solution containing an ultrasonic degreasing agent for ultrasonic degreasing cleaning;

[0058] (2) Using magnetron sputtering to deposit a conductive semiconductor oxide film on an n-type bismuth telluride material substrate;

[0059] (3) Depositing a barrier layer on a conductive semiconductor oxide film using a laser cladding process;

[0060] (4) Welding the copper foil to the barrier layer using ultrasonic welding;

[0061] (5) Cut the bismuth telluride into pellets for later use.

[0062] The above are the embodiments of the present invention. The foregoing are the preferred embodiments of the present invention. If the preferred implementation methods in each preferred embodiment are not obviously self-contradictory or based on a certain preferred implementation method, each preferred implementation method can be arbitrarily superimposed and used in combination. The embodiments and the specific parameters in the embodiments are only for the purpose of clearly describing the verification process of the invention, and are not intended to limit the scope of patent protection of the present invention. The scope of patent protection of the present invention is still subject to its claims. Any equivalent structural changes made by using the contents of the description and drawings of the present invention should also be included in the scope of protection of the present invention.

Claims

1. A packaging structure of a bismuth telluride-based thermoelectric device, characterized in that: The invention comprises a buffer layer (1), a barrier layer (2), and an electrode layer (3) which are sequentially arranged on an n-type bismuth telluride material substrate (4); the material of the buffer layer (1) is a conductive semiconductor oxide; the material of the barrier layer (2) is a metal or a metal alloy; and the material of the electrode layer (3) is a metal or a metal alloy.

2. The packaging structure of a bismuth telluride-based thermoelectric device according to claim 1, characterized in that: The conductive semiconductor oxide is one or more combinations of indium tin oxide, indium oxide, zinc oxide, and tin oxide, and the thickness of the buffer layer (1) is 1-5 μm.

3. The packaging structure of a bismuth telluride-based thermoelectric device according to claim 1, characterized in that: The barrier layer (2) is an alloy of one or more combinations of Ni, Cu, and Mo, and the thickness of the barrier layer (2) is 2-10 μm.

4. The packaging structure of a bismuth telluride-based thermoelectric device according to claim 1, characterized in that: The electrode layer (3) is copper foil, and the thickness of the electrode layer (3) is 5um-50um.

5. A method for preparing a packaging structure of a bismuth telluride-based thermoelectric device according to any one of claims 1 to 4, characterized in that: The following steps are involved: (1) polishing the n-type bismuth telluride material substrate and placing it in a solution containing an ultrasonic degreasing agent for ultrasonic degreasing cleaning; (2) Using magnetron sputtering to deposit a conductive semiconductor oxide film on an n-type bismuth telluride material substrate; (3) Depositing a barrier layer on a conductive semiconductor oxide film using a laser cladding process; (4) Welding the copper foil to the barrier layer using ultrasonic welding; (5) Cut bismuth telluride into pellets for later use.

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