Thermoelectric micro power generation device and preparation method thereof

Abstract

The invention provides a thermoelectric micro power generation device which comprises a bonding layer, an N-type thermoelectric module and a P-type thermoelectric module, wherein the N-type thermoelectric module and the P-type thermoelectric module are located on the two sides of the bonding layer. The N-type thermoelectric module comprises a first substrate, and a T adhesion layer, a metal electrode layer, a first T barrier layer, an N-type thermoelectric material, a second T barrier layer and a first bonding layer which are sequentially deposited on the first substrate; the P-type thermoelectric module comprises a second substrate, and a T adhesion layer, a metal electrode layer, a first N barrier layer, a P-type thermoelectric material, a second N barrier layer and a second bonding layer which are sequentially deposited on the second substrate; and heating and bonding the first bonding layer and the second bonding layer to form a bonding layer. The thermoelectric micro power generation device has many pairs of thermoelectric arms, and has good power generation efficiency at a relatively low temperature difference. The invention also provides a preparation method thereof.

Description

Technical Field

[0001] The present invention relates to the technical field of microelectronic devices, and in particular to a thermoelectric micro-generator device and a preparation method thereof. Background Art

[0002] Thermoelectric devices refer to functional electronic devices based on thermoelectric materials. Through microelectronic processes such as electrode interconnection and packaging, the thermoelectric properties of thermoelectric materials can be effectively applied. Currently, commercial thermoelectric devices on the market usually use a hard block device structure, which cannot meet the cooling needs of microelectronic devices or the needs of flexible sensing.

[0003] With the acceleration of 5G base station construction, the demand for optical modules has increased significantly. In the future, medium- and high-speed optical modules below 100G will be fully upgraded to above 400G. By then, the heat generation power of the core parts of the key modules will rise to 100W / cm 2 Currently, commercial bulk thermoelectric coolers can no longer fully meet the development direction of miniaturization and high integration of thermoelectric arms.

[0004] Compared with bulk thermoelectric devices, thin-film thermoelectric devices have wider application potential and are irreplaceable. The main feature of thin-film thermoelectric devices is that they are close to chips in geometric size, and because their thickness can usually reach the micron level, the stress on the upper and lower surfaces is greatly reduced, and they have the possibility of flexibility. Because of their size comparable to chips, thin-film thermoelectric devices can be compatible with other microelectronic devices, whether as micro-refrigerators or temperature difference generators. At the same time, because they are easy to achieve flexible preparation, they have high application potential in the fields of human body sensing and body temperature power generation.

[0005] However, at present, the main problem of integrating high-performance thermoelectric materials into thermoelectric devices is that there are many conflicts between the preparation process of thermoelectric materials and the integration conditions of devices, such as different heating temperatures, multi-layer heterogeneous interface coupling problems, and the need for thermoelectric materials to cooperate with device micromachining processes. In view of these problems, it is urgent to reasonably design the structure of electrothermal devices, select material construction processes, and obtain compatible equipment preparation processes in the field of thermoelectrics. Summary of the invention

[0006] The present invention provides a thermoelectric micro-generator device, which has a large number of thermoelectric arm pairs and a high power generation power, and can simultaneously meet the requirements of miniaturization of the thermoelectric generator device and high integration of the thermoelectric arms.

[0007] The invention also provides a method for preparing a thermoelectric micro-generator.

[0008] To achieve one or part or all of the above purposes, the present invention provides a thermoelectric micro-generation device, comprising a bonding layer, and an N-type thermoelectric module and a P-type thermoelectric module located on both sides of the bonding layer; wherein the N-type thermoelectric module comprises a first substrate, and a Ti adhesion layer, a metal electrode layer, a first Ti barrier layer, an N-type thermoelectric material, a second Ti barrier layer and a first bonding layer sequentially deposited on the first substrate; the P-type thermoelectric module comprises a second substrate, and a Ti adhesion layer, a metal electrode layer, a first Ni barrier layer, a P-type thermoelectric material, a second Ni barrier layer and a second bonding layer sequentially deposited on the second substrate; the first bonding layer and the second bonding layer are heated and bonded to form the bonding layer. The beneficial effects of the above technical solution include: due to the good adhesion performance of Ti, the use of Ti as the adhesion layer can effectively prevent the device from falling off; the use of Ti barrier layer to adapt N-type thermoelectric materials and Ni barrier layer to adapt P-type thermoelectric materials can not only effectively prevent interface diffusion behavior, but also ensure effective ohmic contact between N-type / P-type thermoelectric materials and the metal electrode layer, thereby improving the power generation efficiency of the device; the above-mentioned thermoelectric micro-power generation device has been tested and has a large number of thermoelectric arm pairs, and can still have good power generation efficiency under relatively low temperature differences, meeting the power generation requirements of micro devices under low temperature difference conditions.

[0009] Preferably, the metal electrode layer is a Cu metal electrode. Since Cu has good electrical conductivity, it meets the requirement of forming ohmic contact between the metal interface of the thermoelectric material and the electrode layer. Compared with metals such as Au and Pt, Cu has a higher cost performance.

[0010] A mixed transition layer of Ti and Cu is also deposited between the Ti adhesion layer and the metal electrode layer of the N-type thermoelectric module or / and the P-type thermoelectric module. Its beneficial effect is that the interface between the subsequent metal electrode layer and the Ti adhesion layer can be greatly optimized, and the subsequent metal electrode layer can be further prevented from falling off; if there is no mixed transition layer, if the Ti adhesion layer is in direct contact with the metal electrode layer, carrier recombination will occur at the interface where the two are in direct contact, which will have a certain impact on the conductive performance of the device.

[0011] The bonding layer uses a eutectic alloy with a melting point lower than 200° C. The beneficial effect is that the low melting point eutectic alloy is used as the bonding layer, the bonding effect is better, and the thermoelectric arm is not easy to break during the bonding process, thereby ensuring the power generation efficiency of the device.

[0012] The first substrate and / or the second substrate are / is an AlN ceramic substrate.

[0013] The present invention also provides a method for preparing a thermoelectric micro-generation device, comprising the following steps: preparing an N-type thermoelectric module, preparing a P-type thermoelectric module, and pairing and bonding the N-type thermoelectric module and the P-type thermoelectric module; wherein the step of preparing the N-type thermoelectric module comprises: providing a first substrate and cleaning the first substrate; sequentially depositing a Ti adhesion layer, a metal electrode layer, and a first Ti barrier layer on the first substrate; depositing an N-type thermoelectric material on the first Ti barrier layer; sequentially depositing a second Ti barrier layer and a first bonding layer on the N-type thermoelectric material; the step of preparing the P-type thermoelectric module comprises: providing a second substrate and cleaning the second substrate; sequentially depositing a Ti adhesion layer, a metal electrode layer, and a first Ni barrier layer on the second substrate; depositing a P-type thermoelectric material on the first Ni barrier layer; sequentially depositing a second Ni barrier layer and a second bonding layer on the P-type thermoelectric material; the pairing and bonding step comprises: heating and bonding the first bonding layer and the second bonding layer, and cooling after bonding is completed.

[0014] The steps of preparing the N-type thermoelectric module or / and preparing the P-type thermoelectric module further include: before depositing the metal electrode layer, sputtering and depositing a mixed transition layer of Ti and Cu on the Ti adhesion layer by magnetron Ti and Cu co-sputtering.

[0015] The co-sputtering process of Ti and Cu is as follows: the sputtering power is 30-50W, the sputtering gas pressure is 1-2Pa, the co-sputtering time is 5-10 minutes, and the deposition temperature is 100-200°C.

[0016] The process for depositing the first bonding layer in preparing the N-type thermoelectric module and the process for depositing the second bonding layer in preparing the P-type thermoelectric module are as follows: using a eutectic alloy with a melting point lower than 200°C as the bonding layer, using magnetron sputtering deposition, with a sputtering power of 20-40W, a sputtering gas pressure of 1-2Pa, and a deposition temperature of 100-150°C.

[0017] The process for preparing the deposited metal electrode layer in the N-type thermoelectric module and the process for preparing the deposited metal electrode layer in the P-type thermoelectric module is: using Cu magnetron sputtering, the sputtering power is 30-50W, the sputtering pressure is 1-2Pa, the sputtering time is 15-20 hours, and the deposition temperature is 100-200°C.

[0018] After the metal electrode layer is prepared, the metal electrode layer is subjected to gold spraying anti-oxidation treatment, and the anti-oxidation treatment can effectively increase the working life of the device.

[0019] The process of depositing N-type thermoelectric material on the first Ti barrier layer is as follows: using magnetron Bi 2 Te 3 The method of double target co-sputtering with Te, Bi2 Te 3 The sputtering power is DC 30-50W, the sputtering power of Te is RF 30-50W, the sputtering gas pressure is 1-2Pa, the temperature of the first substrate is 350-450°C, and the sputtering time is 4-6 hours.

[0020] The process of depositing P-type thermoelectric material on the first Ni barrier layer is as follows: using magnetron Sb 2 Te 3 The method of double target co-sputtering with Te, Bi 2 Te 3 The sputtering power of is 30-50W DC, the sputtering power of Te is 40-60W RF, the sputtering pressure is 1-2Pa, the temperature of the second substrate is 250-350°C, and the sputtering time is 4-6 hours.

[0021] The process of depositing the Ti adhesion layer on the first substrate and the second substrate is: using magnetron sputtering, controlling the substrate temperature at 100-200°C, the Ti sputtering power at 30-50W, the sputtering pressure at 1-2Pa, and the sputtering time at 20-30 minutes.

[0022] The process of depositing the first Ti barrier layer and the second Ti barrier layer on the N-type thermoelectric material is: using magnetron sputtering, the sputtering power is 30-50W, the sputtering gas pressure is 1-2Pa, and the substrate temperature is 100-200°C; the process of depositing the first Ni barrier layer and the second Ni barrier layer on the P-type thermoelectric material is: using magnetron sputtering, the sputtering power is 30-50W, the sputtering gas pressure is 1-2Pa, and the substrate temperature is 100-200°C.

[0023] The beneficial effect of the present invention mainly lies in that the thermoelectric micro-generator device prepared by the above process has a large number of thermoelectric arm pairs and can still have good power generation performance under relatively low temperature difference conditions, thus meeting the needs of micro-generator devices under relatively low temperature difference conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a flow chart of a method for preparing a thermoelectric micro-generation device provided in Example 1 of the present invention.

[0025] Figure 2 It is a test comparison chart of the thermoelectric figure of merit of the N-type thermoelectric module prepared by the preparation method of Example 1 of the present invention and the prior art.

[0026] Figure 3 Schematic diagram of the test of the thermoelectric micro-generator prepared in Example 1.

[0027] Figure 4 yes Figure 3 The test result graph in . DETAILED DESCRIPTION

[0028] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only preferred embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] Embodiment 1 of the present invention provides a method for preparing a thermoelectric micro-generator device. Figure 1 , including the following steps: preparing an N-type thermoelectric module, preparing a P-type thermoelectric module, pairing and bonding the N-type thermoelectric module and the P-type thermoelectric module to form a thermoelectric micro-power generation device.

[0030] The steps of preparing the N-type thermoelectric module include:

[0031] 1.1) Provide a first substrate and clean the first substrate.

[0032] In this step, the first substrate may be a ceramic substrate or a silicon substrate. The ceramic substrate may be, for example, aluminum oxide Al 2 O 3 , aluminum nitride Al N, etc. In this embodiment, Al N is selected as the first substrate, and the cleaning process is specifically: ultrasonic cleaning with acetone, anhydrous ethanol and deionized water for 10-15 minutes respectively, and after cleaning, it is blown dry with dry nitrogen for standby use.

[0033] 1.2) Depositing a Ti adhesion layer on the first substrate after cleaning and drying.

[0034] In this embodiment, Ti is selected as the deposition material of the adhesion layer. The adhesion of Ti can ensure that the Cu thick film with a thickness of tens of microns will not fall off, thereby ensuring the effective deposition of the subsequent metal electrode layer.

[0035] The specific process of depositing the Ti adhesion layer in this embodiment is: magnetron sputtering is used for deposition, the temperature of the first substrate is controlled between 100-200°C, the sputtering power of Ti is controlled between 30-50W, the sputtering pressure is between 1-2Pa, and the sputtering time is 20-30 minutes. The above sputtering process parameters can ensure that the thickness of the Ti adhesion layer is moderate and the thickness uniformity is good, which does not affect the conductivity of the device and can ensure that the subsequent metal electrode layer does not fall off.

[0036] In other embodiments, other physical vapor deposition methods may also be used to deposit the Ti adhesion layer, such as an evaporation process. However, since the density of the Ti adhesion layer formed by the evaporation process is not as good as that by magnetron sputtering, the Ti adhesion layer formed by the evaporation process is easier to fall off than that by magnetron sputtering. Therefore, magnetron sputtering is preferably used in this embodiment.

[0037] 1.3) Depositing a mixed transition layer of Ti and Cu on the Ti adhesion layer.

[0038] The mixed transition layer is a preferred step because it can greatly optimize the interface between the subsequent metal electrode layer and the Ti adhesion layer, and can further prevent the subsequent electrode layer from falling off. If there is no mixed transition layer, and the Ti adhesion layer is in direct contact with the metal electrode layer, carrier recombination will occur at the interface where the two are in direct contact, which will have a certain impact on the conductive performance of the device.

[0039] The specific process is: firstly, a magnetron Ti and Cu co-sputtering method is used on the Ti adhesion layer to sputter and deposit a mixed transition layer of Ti and Cu, with a sputtering power of 30-50W, a sputtering pressure of 1-2Pa, a co-sputtering time of 5-10 minutes, and a deposition temperature of 100-200° C. The sputtering parameters of the mixed transition layer can ensure that the mixed transition layer has good compactness, can form ohmic contact with subsequent thermoelectric materials, and can effectively prevent the diffusion of the metal electrode layer material in the subsequent deposition of N-type thermoelectric materials, which affects the performance of the thermoelectric arm.

[0040] It should be noted that, in other embodiments, the process step 1.3) may not be performed, and the process step 1.4) may be performed directly after the process step 1.2) is completed.

[0041] 1.4) Continue to deposit the metal electrode layer.

[0042] In this embodiment, Cu is preferably used as the material of the metal electrode. In other embodiments, Au, Pt and other metals may also be selected as the deposition material of the metal electrode layer.

[0043] The preparation process is: Cu magnetron sputtering, sputtering power is 30-50W, sputtering pressure is 1-2Pa, sputtering time is 15-20 hours, and deposition temperature is 100-200°C. After the electrode preparation is completed, the metal electrode is also subjected to gold spraying anti-oxidation treatment in this embodiment to prevent electrode oxidation and improve the working life of the device. The parameters of the above preparation process can ensure that the thickness of the Cu film is as large as possible, and the Cu film has good density and is not easy to fall off.

[0044] 1.5) Depositing a first Ti barrier layer on the metal electrode layer.

[0045] The deposition process of the Ti barrier layer in this embodiment is: magnetron sputtering, with a sputtering power of 30-50 W, a sputtering pressure of 1-2 Pa, and a substrate temperature of 100-200°C.

[0046] Depositing a barrier layer on the metal electrode layer can effectively prevent interface diffusion behavior, and selecting Ti with a smaller work function as the barrier layer of the N-type thermoelectric module can ensure effective ohmic contact between the subsequent N-type thermoelectric material and the metal electrode layer.

[0047] 1.6) Depositing N-type thermoelectric material on the first Ti barrier layer to form an N-type thermoelectric arm.

[0048] The preparation process used in this embodiment is: select N-type Bi 2 Te 3 Material, using magnetron Bi 2 Te 3 The method of double target co-sputtering with Te, Bi 2 Te 3 The sputtering power is DC 30-50W, the sputtering power of Te is RF 30-50W, the sputtering gas pressure is 1-2Pa, the temperature of the first substrate is 350-450°C, and the sputtering time is 4-6 hours.

[0049] The process parameters of the above N-type thermoelectric materials can ensure that the thermoelectric figure of merit ZT of the thermoelectric materials is high. Please refer to Figure 2 It can be seen that the thermoelectric figure of merit ZT of the N-type thermoelectric arm with a film thickness of more than 10 microns prepared by the process parameters in this embodiment exceeds 1.0, while the ZT value of the same thickness film prepared by the unoptimized process parameters in the prior art is less than 0.3.

[0050] 1.7) Depositing a second Ti barrier layer on the N-type thermoelectric material.

[0051] The preparation process is the same as that in step 1.5) and will not be described in detail here.

[0052] 1.8) Depositing a first bonding layer on the second Ti barrier layer.

[0053] A eutectic alloy with a melting point below 200°C is used as the bonding layer, and magnetron sputtering deposition is used, with a sputtering power of 20-40W, a sputtering pressure of 1-2Pa, and a deposition temperature of 100-150°C. The above process parameters can ensure the uniformity of the bonding layer film thickness, ensure the smooth completion of the bonding process, and have a high device yield.

[0054] In addition, in this embodiment, the low melting point eutectic alloy Sn In alloy is preferably used as the bonding layer. The bonding effect of Sn In material is better, and the thermoelectric arm is not easy to break during the bonding process, thereby ensuring the power generation efficiency of the device.

[0055] The steps of preparing a P-type thermoelectric module include:

[0056] 2.1) Provide a second substrate and clean the second substrate.

[0057] This step is the same as the process 1.1) for preparing the N-type thermoelectric module, and will not be described in detail here.

[0058] 2.2) Depositing a Ti adhesion layer on the cleaned and dried second substrate.

[0059] This step is the same as the process 1.2) for preparing the N-type thermoelectric module, and will not be described in detail here.

[0060] 2.3) Depositing a mixed transition layer of Ti and Cu on the Ti adhesion layer.

[0061] This step is the same as the process 1.3) for preparing an N-type thermoelectric module, and will not be described in detail here. Similarly, in this embodiment, step 2.3) is an optional step. In other embodiments, step 2.3) may not be performed, and step 2.4) may be performed directly after step 2.2) is completed.

[0062] 2.4) Continue to deposit the metal electrode layer.

[0063] This step is the same as the process 1.4) for preparing the N-type thermoelectric module, and will not be described in detail here.

[0064] 2.5) Depositing a first Ni barrier layer on the metal electrode layer.

[0065] The process parameters are the same as those in 1.5), but Ni is selected as the deposition material, and Ni with a higher work function is selected as the barrier layer of the P-type thermoelectric module to ensure effective ohmic contact between the P-type thermoelectric material and the metal layer.

[0066] 2.6) Depositing a P-type thermoelectric material on the first Ni barrier layer to form a P-type thermoelectric arm.

[0067] The preparation process used in this embodiment is: using P-type Sb 2 Te 3 Material, using magnetron Sb 2 Te 3 The method of double target co-sputtering with Te, Bi 2 Te 3 The sputtering power of is 30-50W DC, the sputtering power of Te is 40-60W RF, the sputtering pressure is 1-2Pa, the temperature of the second substrate is 250-350°C, and the sputtering time is 4-6 hours.

[0068] The process parameters of the above-mentioned P-type thermoelectric material can ensure that the thermoelectric figure of merit ZT of the thermoelectric material is high. The thermoelectric figure of merit ZT of the P-type thermoelectric arm with a thickness of more than 10 microns prepared by the process parameters in this embodiment exceeds

[0069] 1.2, while the ZT value of the same thickness film prepared without optimizing the process parameters in the prior art is less than 0.3.

[0070] 2.7) Depositing a second Ni barrier layer on the P-type thermoelectric material.

[0071] The preparation process is the same as that in step 2.5) and will not be described in detail here.

[0072] 2.8) Depositing a second bonding layer on the second Ni barrier layer.

[0073] This step is the same as the process 1.8) for preparing the N-type thermoelectric module, and will not be described in detail here.

[0074] The step of pairing and bonding the N-type thermoelectric module and the P-type thermoelectric module to form a thermoelectric micro-power generation device includes: aligning the first bonding layer and the second bonding layer, heating and bonding, forming an N-type-P-type thermoelectric arm pair, and cooling after bonding. Specifically, the heating temperature in this embodiment is about 200°C, the heating time is about 5 minutes, the pressure is 500g, and slow cooling is performed after bonding.

[0075] This embodiment also provides a thermoelectric power generation device, including a bonding layer, and an N-type thermoelectric module and a P-type thermoelectric module located on both sides of the bonding layer. The N-type thermoelectric module includes a first substrate, and a Ti adhesion layer, a mixed transition layer, a metal electrode layer, a first Ti barrier layer, an N-type thermoelectric material, a second Ti barrier layer and a first bonding layer sequentially deposited on the first substrate; the P-type thermoelectric module includes a second substrate, and a Ti adhesion layer, a mixed transition layer, a metal electrode layer, a first Ni barrier layer, a P-type thermoelectric material, a second Ni barrier layer and a second bonding layer sequentially deposited on the second substrate; the first bonding layer and the second bonding layer are heated and bonded to form a bonding layer.

[0076] Preferably, the metal electrode layer is a Cu metal electrode, and the mixed transition layer is a mixed layer of Ti and Cu. In other embodiments, the mixed transition layer may not be provided. The bonding layer uses a eutectic alloy with a melting point lower than 200° C. as the bonding layer. In this embodiment, Sn In material is sputtered. The first substrate and the second substrate are Al N ceramic substrates.

[0077] The thermoelectric micro-generator device produced by the above process, taking the characteristic size of 8mm*8mm*1.6mm as an example, has 324 pairs of thermoelectric arms and an internal resistance of 6.6Ω. Under the condition of a temperature difference of 10k, the power generation power of the tested device exceeds 0.1mW. In the prior art, the number of thermoelectric arms of the same size is less than 100 pairs, and it is impossible to obtain a higher power generation power in an environment with a low temperature difference such as a 10k temperature difference.

[0078] Figure 3 The test schematic diagram of the above-mentioned thermoelectric micro-generation device is shown. Figure 3Thermoelectric device performance test platform in the test, the hot end and cold end are high thermal conductivity metal, to ensure the uniformity of the temperature of the hot end and cold end objects themselves, such as aluminum alloy, so that a temperature difference will be formed at both ends of the device, and then the electrical performance of the thermoelectric micro-generation device is tested. The test results are as follows Figure 4 As shown in the figure, it can be seen that the curve part is the output power spectrum of the device under a temperature difference of 10K. It can be found that when the voltage is 40mV, the output power of the device is the largest, which can reach more than 0.1mW.

Claims

1. A thermoelectric micro-generator, characterized in that: It includes a bonding layer, and an N-type thermoelectric module and a P-type thermoelectric module located on both sides of the bonding layer; wherein, The N-type thermoelectric module comprises a first substrate, and a Ti adhesion layer, a metal electrode layer, a first Ti barrier layer, an N-type thermoelectric material, a second Ti barrier layer and a first bonding layer sequentially deposited on the first substrate; The P-type thermoelectric module includes a second substrate, and a Ti adhesion layer, a metal electrode layer, a first Ni barrier layer, a P-type thermoelectric material, a second Ni barrier layer and a second bonding layer sequentially deposited on the second substrate; The first bonding layer and the second bonding layer are heated and bonded to form the bonding layer.

2. The thermoelectric micro-generator device according to claim 1, characterized in that: The metal electrode layer is a Cu metal electrode.

3. The thermoelectric micro-generator device according to claim 2, characterized in that: A mixed transition layer of Ti and Cu is also deposited between the Ti adhesion layer and the metal electrode layer of the N-type thermoelectric module and / or the P-type thermoelectric module.

4. The thermoelectric micro-generator device according to claim 1, characterized in that: The bonding layer uses a eutectic alloy with a melting point lower than 200° C. as the bonding layer.

5. The method for preparing a thermoelectric micro-generator device according to any one of claims 1 to 4, characterized in that: The first substrate and / or the second substrate is an AlN ceramic substrate.

6. A method for preparing a thermoelectric micro-generator device, characterized in that: The method comprises the following steps: preparing an N-type thermoelectric module, preparing a P-type thermoelectric module, and pairing and bonding the N-type thermoelectric module and the P-type thermoelectric module; wherein, The steps of preparing the N-type thermoelectric module include: providing a first substrate and cleaning the first substrate; depositing a Ti adhesion layer, a metal electrode layer, and a first Ti barrier layer on the first substrate in sequence; depositing an N-type thermoelectric material on the first Ti barrier layer; and depositing a second Ti barrier layer and a first bonding layer on the N-type thermoelectric material in sequence; The steps of preparing the P-type thermoelectric module include: providing a second substrate and cleaning the second substrate; depositing a Ti adhesion layer, a metal electrode layer, and a first Ni barrier layer on the second substrate in sequence; depositing a P-type thermoelectric material on the first Ni barrier layer; and depositing a second Ni barrier layer and a second bonding layer on the P-type thermoelectric material in sequence; The pair bonding step includes: heating and bonding the first bonding layer and the second bonding layer, and cooling after bonding.

7. The method for preparing a thermoelectric micro-generator device according to claim 6, characterized in that: The steps of preparing the N-type thermoelectric module or / and preparing the P-type thermoelectric module further include: before depositing the metal electrode layer, sputtering and depositing a mixed transition layer of Ti and Cu on the Ti adhesion layer by magnetron Ti and Cu co-sputtering.

8. The method for preparing a thermoelectric micro-generator device according to claim 7, characterized in that: The co-sputtering process of Ti and Cu is as follows: the sputtering power is 30-50W, the sputtering gas pressure is 1-2Pa, the co-sputtering time is 5-10 minutes, and the deposition temperature is 100-200°C.

9. The method for preparing a thermoelectric micro-generator device according to claim 6, characterized in that: The process for depositing the first bonding layer in preparing the N-type thermoelectric module and the process for depositing the second bonding layer in preparing the P-type thermoelectric module are as follows: using a eutectic alloy with a melting point lower than 200°C as the bonding layer, using magnetron sputtering deposition, with a sputtering power of 20-40W, a sputtering gas pressure of 1-2Pa, and a deposition temperature of 100-150°C.

10. The method for preparing a thermoelectric micro-generator device according to claim 6, characterized in that: The process for preparing the deposited metal electrode layer in the N-type thermoelectric module and the process for preparing the deposited metal electrode layer in the P-type thermoelectric module is: using Cu magnetron sputtering, the sputtering power is 30-50W, the sputtering pressure is 1-2Pa, the sputtering time is 15-20 hours, and the deposition temperature is 100-200°C.

11. The method for preparing a thermoelectric micro-generator device according to claim 10, characterized in that: After the metal electrode layer is prepared, the metal electrode layer is subjected to gold spraying anti-oxidation treatment.

12. The method for preparing a thermoelectric micro-generator device according to claim 6, characterized in that: The process for depositing N-type thermoelectric material on the first Ti barrier layer is: using magnetron Bi2Te3 and Te dual target co-sputtering, the sputtering power of Bi2Te3 is DC 30-50W, the sputtering power of Te is RF 30-50W, the sputtering gas pressure is 1-2Pa, the first substrate temperature is 350-450℃, and the sputtering time is 4-6 hours.

13. The method for preparing a thermoelectric micro-generator device according to claim 6, characterized in that: The process for depositing P-type thermoelectric material on the first Ni barrier layer is: using magnetron Sb2Te3 and Te dual target co-sputtering, the sputtering power of Bi2Te3 is DC 30-50W, the sputtering power of Te is RF 40-60W, the sputtering gas pressure is 1-2Pa, the temperature of the second substrate is 250-350℃, and the sputtering time is 4-6 hours.

14. The method for preparing a thermoelectric micro-generator device according to claim 6, characterized in that: The process of depositing the Ti adhesion layer on the first substrate and the second substrate is: using magnetron sputtering, controlling the substrate temperature at 100-200°C, the Ti sputtering power at 30-50W, the sputtering pressure at 1-2Pa, and the sputtering time at 20-30 minutes.

15. The method for preparing a thermoelectric micro-generator device according to claim 6, characterized in that: The process of depositing the first Ti barrier layer and the second Ti barrier layer on the N-type thermoelectric material is: using magnetron sputtering, the sputtering power is 30-50W, the sputtering pressure is 1-2Pa, and the substrate temperature is 100-200°C; The process of depositing the first Ni barrier layer and the second Ni barrier layer on the P-type thermoelectric material is: using magnetron sputtering, the sputtering power is 30-50W, the sputtering pressure is 1-2Pa, and the substrate temperature is 100-200°C.

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