ITO (indium tin oxide) / In2O3 thin film thermocouple compensation wire as well as preparation method and application thereof

Abstract

The invention belongs to the technical field of high-temperature thin film sensors, and particularly discloses an ITO / In2O3 thin film thermocouple compensation wire and a preparation method and application thereof.The ITO / In2O3 thin film thermocouple compensation wire sequentially comprises a polytetrafluoroethylene substrate, an oxide thermoelectric thin film and a sheath layer from inside to outside, the oxide thermoelectric thin film is grown on the surface of the tetrafluoroethylene substrate in a conformal mode, and the oxide thermoelectric thin film is an ITO thin film or an In2O3 thin film. According to the ITO / In2O3 thin film thermocouple compensation lead, the measurement error caused by the temperature change of the reference end is effectively reduced, the blank that the reference end of the ITO / In2O3 thin film thermocouple has no compensation lead in the prior art is filled, and the temperature measurement precision is remarkably improved; the cable can stably work in a high-temperature environment, and the temperature range can reach 250 DEG C; and meanwhile, the composite material has the characteristics of light weight, flexibility and bendability, the use flexibility is improved, and the composite material can adapt to application under complex working conditions.

Description

Technical Field

[0001] The present invention belongs to the technical field of high temperature thin film sensors, and specifically relates to an ITO / In 2 O 3 Thin film thermocouple compensation wire and its preparation method and application. Background Art

[0002] The working principle of the compensation wire is based on the thermoelectric effect. It uses a wire that matches the thermocouple material to compensate for the measurement error caused by the temperature change of the reference end, thereby improving the accuracy of temperature measurement. The compensation wire is usually composed of a wire with the same nominal value of the thermoelectric electromotive force as the thermocouple. It is mainly used to connect the thermocouple and the measuring device to compensate for the error caused by the temperature change at the thermocouple connection. 2 O 3 Thin film thermocouples have excellent high temperature stability, conductivity and transparency, and can accurately measure temperature changes in high temperature environments. Their small size and fast response characteristics make them particularly suitable for miniaturized sensors. At the same time, they have strong corrosion resistance and can work stably in harsh environments. With the growing demand for high temperature and accurate temperature monitoring, ITO / In 2 O 3 Thin film thermocouples have shown broad application prospects in industry, aerospace, automobile and other fields.

[0003] However, due to the current ITO / In 2 O 3 Due to the particularity of thin film thermocouple materials, there is no reliable compensation wire that can effectively compensate for the measurement error caused by the temperature fluctuation of the reference end. This technical bottleneck limits the development of ITO / In 2 O 3 Application of thin film thermocouples in high-precision temperature monitoring. 2 O 3 The wide application of thin film thermocouples in high-precision temperature monitoring urgently requires the development of a special ITO / In 2 O 3 The compensation wire of thin film thermocouple opens up its application prospect in the field of high temperature measurement. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide an ITO / In 2 O 3 Thin-film thermocouple compensation wires and their preparation methods and applications are intended to reduce measurement errors caused by changes in the reference end temperature of thin-film thermocouples and to improve the stability and accuracy of high-precision temperature monitoring.

[0005] In order to achieve the above purpose, one of the technical solutions of the present invention is: an ITO / In2 O 3 The thin film thermocouple compensation wire comprises, from inside to outside, a polytetrafluoroethylene substrate, an oxide thermoelectric film and a sheath layer, wherein the oxide thermoelectric film is conformally grown on the surface of the polytetrafluoroethylene substrate, and the oxide thermoelectric film is an ITO film or an In 2 O 3 film.

[0006] PTFE substrate has good flexibility and bendability, and is resistant to high temperatures. 2 O 3 The film grows conformally on the surface of the substrate, has a dense morphology, and a continuous conductive path. The sheath layer can achieve high temperature resistance, bendability, and excellent dielectric insulation, which can effectively protect the internal structure while realizing the function of detachable assembly.

[0007] In a preferred embodiment of the present invention, the polytetrafluoroethylene substrate is a cylindrical long tube with a diameter of 0.4-0.8 mm, light in weight and a temperature resistance exceeding 200°C.

[0008] In a preferred embodiment of the present invention, the oxide thermoelectric thin film has a thickness of 2-4 μm.

[0009] In a preferred embodiment of the present invention, the sheath layer is woven from quartz fibers, the instantaneous temperature resistance of the sheath layer exceeds 600°C, and the maximum long-term use temperature is not higher than 900°C.

[0010] In a preferred embodiment of the present invention, the ITO / In 2 O 3 Thin film thermocouple compensation wire can compensate the temperature between -50-250℃.

[0011] In a preferred embodiment of the present invention, the ITO / In 2 O 3 The bending radius of the thin film thermocouple compensation wire shall not be less than 85mm (the maximum bending radius can be infinite, that is, unbent).

[0012] In order to achieve the above purpose, the second technical solution of the present invention is: an ITO / In 2 O 3 Application of thin film thermocouple compensation wire in high-precision temperature monitoring.

[0013] In order to achieve the above purpose, the third technical solution of the present invention is: an ITO / In 2 O 3 The method for preparing a thin film thermocouple compensation wire comprises the following steps:

[0014] S1: High temperature aging treatment of the polytetrafluoroethylene substrate, followed by bending aging treatment;

[0015] S2: cleaning the polytetrafluoroethylene substrate treated in step S1 and flushing with high-speed nitrogen to remove surface impurities;

[0016] S3: forming an oxide thermoelectric film on the bottom surface of the polytetrafluoroethylene treated in step S2 by a magnetron sputtering process;

[0017] S4: annealing the polytetrafluoroethylene substrate with the oxide thermoelectric film formed on the surface obtained in step S3;

[0018] S5: Assembling a sheath layer on the surface of the oxide thermoelectric thin film treated in step S4.

[0019] In a preferred embodiment of the present invention, the temperature of the high temperature aging treatment in step S1 is 180-220°C, and the insulation time is 3-5h, so as to achieve a stable state of thermal expansion and achieve aging, and the heating rate is 1.5-2.5°C / min.

[0020] In a preferred embodiment of the present invention, the bending aging treatment in step S1 is to repeatedly bend the polytetrafluoroethylene substrate after high-temperature aging treatment until the curvature radius reaches 50 mm to achieve bending aging; the bending process can simulate the bending stress in actual applications to ensure the stability and durability of the compensation wire in long-term use.

[0021] In a preferred embodiment of the present invention, the annealing treatment in step S4 is performed in an air atmosphere, the annealing temperature is 200-250° C., and the annealing time is 1.5-2.5 h.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. ITO / In of the present invention 2 O 3 Thin-film thermocouple compensation wire effectively reduces the measurement error caused by the temperature change of the reference end, filling the gap between ITO / In 2 O 3 The reference end of the thin film thermocouple has no blank compensation wire, which significantly improves the temperature measurement accuracy;

[0024] 2. ITO / In of the present invention 2 O 3 Thin-film thermocouple compensation wire can work stably in high-temperature environment, and the temperature range can reach 250℃;

[0025] 3. ITO / In of the present invention 2 O 3Thin-film thermocouple compensation wires are lightweight, flexible, and bendable, which increases their flexibility and allows them to be used in complex working conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is the ITO / In in Example 1 of the present invention. 2 O 3 Schematic diagram of the compensation wire of the thin film thermocouple;

[0027] Figure 2 It is the ITO / In in Example 1 of the present invention. 2 O 3 Schematic diagram of the cross section of the thermoelectric thin film compensation wire;

[0028] Figure 3 It is the ITO / In in Example 1 of the present invention. 2 O 3 Schematic diagram of the three-dimensional structure of the thermoelectric film compensation wire;

[0029] Figure 4 It is the ITO / In in Example 1 of the present invention. 2 O 3 Flow chart of the manufacturing process of thermoelectric thin film compensation wire;

[0030] Figure 5 It is the ITO / In in Example 3 of the present invention. 2 O 3 Schematic diagram of thin film thermocouple compensation wire applied to aircraft engine turbine blades.

[0031] In the figure: 1-PTFE substrate, 2-ITO thermoelectric film, 3-sheath layer, 4-high temperature insulation layer, 5-ITO / In 2 O 3 Thin film thermocouple, 6-silver solder joint, 7-compensation wire. DETAILED DESCRIPTION

[0032] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is described in more detail below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited to these embodiments.

[0033] An ITO / In 2 O 3 The thin film thermocouple compensation wire comprises, from inside to outside, a polytetrafluoroethylene substrate, an oxide thermoelectric film and a sheath layer, wherein the oxide thermoelectric film is conformally grown on the surface of the polytetrafluoroethylene substrate, and the oxide thermoelectric film is an ITO film or an In 2 O 3 film.

[0034] The polytetrafluoroethylene-based substrate is a cylindrical long tube with a diameter of 0.4-0.8 mm, light in weight, and heat-resistant capability exceeding 200°C.

[0035] The oxide thermoelectric film has a thickness of 2-4 μm.

[0036] The sheath layer is woven from quartz fibers.

[0037] The ITO / In 2 O 3 Thin film thermocouple compensation wire can compensate the temperature between -50-250℃.

[0038] The ITO / In 2 O 3 The bending radius of the thin film thermocouple compensation wire shall not be less than 85mm.

[0039] An ITO / In 2 O 3 Application of thin film thermocouple compensation wire in high-precision temperature monitoring.

[0040] An ITO / In 2 O 3 The method for preparing a thin film thermocouple compensation wire comprises the following steps:

[0041] S1: High temperature aging treatment of the polytetrafluoroethylene substrate, followed by bending aging treatment;

[0042] S2: cleaning the polytetrafluoroethylene substrate treated in step S1 and flushing with high-speed nitrogen to remove surface impurities;

[0043] S3: forming an oxide thermoelectric film on the bottom surface of the polytetrafluoroethylene treated in step S2 by a magnetron sputtering process;

[0044] S4: annealing the polytetrafluoroethylene substrate with the oxide thermoelectric film formed on the surface obtained in step S3;

[0045] S5: Assembling a sheath layer on the surface of the oxide thermoelectric thin film treated in step S4.

[0046] The temperature of the high temperature aging treatment in step S1 is 180-220°C, and the insulation time is 3-5h, so that it can reach a stable state of thermal expansion and achieve aging, and the heating rate is 1.5-2.5°C / min.

[0047] The bending aging treatment in step S1 is to repeatedly bend the polytetrafluoroethylene substrate after high temperature aging treatment until the curvature radius reaches 50 mm to achieve bending aging.

[0048] In a preferred embodiment of the present invention, the annealing treatment in step S4 is performed in an air atmosphere, the annealing temperature is 200-250° C., and the annealing time is 1.5-2.5 h.

[0049] Example 1

[0050] refer to Figure 1 This embodiment discloses an ITO / In 2 O 3 Thermoelectric film compensation wire, ITO / In 2 O 3 Thermoelectric film compensation wire A realizes signal interconnection with the corresponding type of film thermocouple C through welding point B, which can effectively reduce the test error caused by temperature fluctuation at the reference end of film thermocouple C. Its cross-sectional diagram is shown as follows Figure 2 As shown, from inside to outside, there are polytetrafluoroethylene substrate 1, ITO thermoelectric film 2, and sheath layer 3. Figure 3 The schematic diagram of its three-dimensional structure. The ITO thermoelectric film compensation wire has certain flexibility and bendability, in which the ITO thermoelectric film 2 conformally grows on the surface of the polytetrafluoroethylene substrate 1, and the sheath layer 3 realizes the function of detachable assembly. The polytetrafluoroethylene substrate is a cylindrical long tube with a diameter of 0.8mm, light weight, and a temperature resistance of more than 200℃. The thickness of the ITO thermoelectric film is 2μm, and the sheath layer is woven from quartz fibers. ITO / In 2 O 3 Thin film thermocouple compensation wire can compensate temperature between -50-250℃, ITO / In 2 O 3 The bending radius of the thin film thermocouple compensation wire shall not be less than 85mm.

[0051] Figure 4 Is ITO / In 2 O 3 Flowchart of the manufacturing process of thermoelectric thin film compensation wire.

[0052] An ITO / In 2 O 3 Thermoelectric film compensation wire is obtained by the following preparation steps:

[0053] S1: Perform high-temperature aging treatment on the polytetrafluoroethylene substrate: Place the substrate in an annealing furnace with a heating rate of 2℃ / min, heat it to 200℃ and keep it warm for 4 hours to make it reach a stable state of thermal expansion and achieve aging; then install it in a bending device and perform more than 5000 bending aging with a curvature radius of 50mm to make it reach a stable state of bending deformation and achieve aging. The bending process can simulate the bending stress in actual applications to ensure the stability and durability of the compensation wire in long-term use;

[0054] S2: After the polytetrafluoroethylene substrate treated in step S1 is cleaned with alcohol, impurities on its surface are flushed with a high-speed nitrogen flow to provide a clean substrate surface for subsequent thin film deposition;

[0055] S3: placing the polytetrafluoroethylene substrate treated in step S2 in the chamber of a magnetron sputtering machine, and then using ITO with a purity of not less than 99.99wt% as a target material, sputtering the ITO thermoelectric film by radio frequency magnetron sputtering, and the vacuum degree of the chamber is less than 8×10 -4 Pa, the working gas pressure is 0.8Pa, Ar=80sccm, the substrate temperature is 200℃, and pre-sputtering is performed after the sputtering conditions are met, followed by long-term stable sputtering, and the final sputtering thickness is 2μm;

[0056] S4: Annealing the polytetrafluoroethylene substrate with the ITO thermoelectric film formed on the surface obtained in step S3. The specific steps are to place it in an annealing furnace, in an air atmosphere, at a heating rate of 2°C / min, raise the temperature to 200°C and keep it warm for 2 hours to ensure the structural stability and electrical properties of the film.

[0057] S5: Assemble the sheath layer onto the ITO / In after annealing in step S4 2 O 3 The surface of the thermoelectric film is insulated and protected, and 5 mm of length is exposed at both ends of the polytetrafluoroethylene substrate for subsequent electrical interconnection of the leads.

[0058] Example 2

[0059] An ITO / In 2 O 3 Thermoelectric film compensation wire, from inside to outside, is made of polytetrafluoroethylene base, In 2 O 3 Thermoelectric film, sheath layer, including In 2 O 3 The thermoelectric film is conformally grown on the surface of the polytetrafluoroethylene substrate, and the sheath layer realizes the function of detachable assembly; the polytetrafluoroethylene substrate is a cylindrical long tube with a diameter of 0.8 mm. 2 O 3 The thickness of the thermoelectric film is 2μm, the sheath layer is woven from quartz fiber, and the ITO / In 2 O 3 Thin film thermocouple compensation wire can compensate temperature between -50-250℃, ITO / In 2 O 3 The bending radius of the thin film thermocouple compensation wire shall not be less than 85mm.

[0060] The above ITO / In 2 O 3The preparation method of the thermoelectric thin film compensation wire is the same as that of Example 1, except that the target material in step S3 is In 2 O 3 .

[0061] Example 3

[0062] ITO / In 2 O 3 The cold end temperature of thin film thermocouples is difficult to stably control, making cold end temperature monitoring a technical problem. In actual work, due to the limitation of cold end temperature fluctuation, the monitoring parameters of the sensor may differ, resulting in deviations in the test results, and even in severe cases, causing health monitoring component failure. The compensation wire in the present invention can be widely used in ITO / In 2 O 3 High temperature monitoring scenarios of thin film thermocouples. Figure 5 , wherein the compensation wire in Example 1 is used for cold end compensation of the surface temperature monitoring of the guide blade of an aircraft engine. Specifically, based on the ITO / In 2 O 3 The thin film thermocouple 5 realizes signal interconnection through the silver solder joint 6 and the compensation wire 7. In practical applications, the cold end temperature is transmitted to the low temperature controllable compensation end through the compensation wire, thereby realizing compensation perception and ensuring the accuracy and stability of the monitoring system.

[0063] ITO / In of the present invention 2 O 3 Thin-film thermocouple compensation wire has significant innovation and application value. First, the use of flexible polytetrafluoroethylene (PTFE) as the base material makes the wire have excellent flexibility and high temperature tolerance, and can work stably under complex working conditions. Secondly, the magnetron sputtering process is used to deposit ITO or In 2 O 3 Thermoelectric film ensures the uniformity and high conductivity of the film, ensuring the reliability of the compensation wire in high-precision temperature measurement. By precisely controlling the sputtering conditions, the quality of the film is optimized, thereby reducing the measurement error caused by changes in the reference end temperature and improving the measurement accuracy of the thin film thermocouple. In addition, the annealing treatment further optimizes the lattice structure of the film, enhancing its thermoelectric properties and long-term stability. During the implementation process, the aging and pretreatment of the polytetrafluoroethylene substrate and the deposition and annealing of the film all need to be strictly controlled to ensure the flexibility, stability and performance of the wire. The compensation wire works based on the thermoelectric effect and can effectively compensate for the thermocouple measurement error caused by changes in ambient temperature, thereby improving the overall measurement accuracy. The present invention fills the gap between ITO / In 2 O 3The technical gap of thin-film thermocouple reference junction compensation has broad application prospects, especially in the field of high-temperature and high-precision temperature monitoring.

[0064] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some or all of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An ITO / In2O3 thin film thermocouple compensation wire, characterized in that: From the inside to the outside, it includes a polytetrafluoroethylene substrate, an oxide thermoelectric film and a sheath layer. The oxide thermoelectric film is conformally grown on the surface of the polytetrafluoroethylene substrate. The oxide thermoelectric film is an ITO film or an In2O3 film.

2. The ITO / In2O3 thin film thermocouple compensation wire according to claim 1, characterized in that: The polytetrafluoroethylene base is a cylindrical long tube with a diameter of 0.4-0.8 mm.

3. The ITO / In2O3 thin film thermocouple compensation wire according to claim 1, characterized in that: The oxide thermoelectric film has a thickness of 2-4 μm.

4. The ITO / In2O3 thin film thermocouple compensation wire according to claim 1, characterized in that: The sheath layer is woven from quartz fibers.

5. The ITO / In2O3 thin film thermocouple compensation wire according to claim 1, characterized in that: The ITO / In2O3 thin film thermocouple compensation wire can compensate the temperature within the range of -50-250°C.

6. The ITO / In2O3 thin film thermocouple compensation wire according to claim 1, characterized in that: The ITO / In2O3 thin film thermocouple compensation wire has a bending radius of not less than 85 mm.

7. Application of the ITO / In2O3 thin film thermocouple compensation wire as claimed in any one of claims 1 to 6 in high-precision temperature monitoring.

8. A method for preparing an ITO / In2O3 thin film thermocouple compensation wire as claimed in any one of claims 1 to 6, characterized in that: The following steps are involved: S1: High temperature aging treatment of the polytetrafluoroethylene substrate, followed by bending aging treatment; S2: cleaning the polytetrafluoroethylene substrate treated in step S1 and flushing with high-speed nitrogen to remove surface impurities; S3: forming an oxide thermoelectric film on the bottom surface of the polytetrafluoroethylene treated in step S2 by a magnetron sputtering process; S4: annealing the polytetrafluoroethylene substrate with the oxide thermoelectric film formed on the surface obtained in step S3; S5: Assembling a sheath layer on the surface of the oxide thermoelectric thin film treated in step S4.

9. The method for preparing the ITO / In2O3 thin film thermocouple compensation wire according to claim 8, characterized in that: The temperature of the high temperature aging treatment in step S1 is 180-220°C, the holding time is 3-5h, the heating rate is 1.5-2.5°C / min, and the bending aging treatment is to bend the polytetrafluoroethylene substrate after the high temperature aging treatment to a curvature radius of 50mm.

10. The method for preparing the ITO / In2O3 thin film thermocouple compensation wire according to claim 8, characterized in that: The annealing treatment in step S4 is performed in an air atmosphere, the annealing temperature is 200-250° C., and the annealing time is 1.5-2.5 hours.

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