Quick-response heat flow ceramic film temperature sensor and preparation method thereof

Abstract

The invention belongs to the technical field of temperature sensing, and discloses a quick-response heat flow ceramic film temperature sensor and a preparation method thereof, an Hf doped In2O3 (IHFO) ceramic film is selected as a thermoelectric arm to be in contact with the In2O3 ceramic film to form a thermocouple type temperature sensor, and a hard mask is combined with a magnetron sputtering process to prepare the temperature sensor. The thermal stability of the structure of indium oxide is reserved, oxygen vacancies in the indium oxide thin film are compensated, the defect density is reduced, meanwhile, the carrier concentration is reduced, and the carrier migration rate is increased; a traditional mode of improving the monitoring temperature by sacrifice materials is replaced by regulating and controlling the crystal structure and the defect density, the thickness of the thin film is reduced, array integration of the sensor is promoted, and shortening of the response time of the device is promoted through high carrier mobility.

Description

Technical Field

[0001] The present invention belongs to the technical field of temperature sensing, and in particular, relates to a high-temperature heat flow functional ceramic thin film temperature sensor capable of rapid response and a preparation method thereof. Background Art

[0002] Aircraft turbofan engines, as the "heart" of aircraft, are an indispensable part of the field of high-end equipment manufacturing. The development trend of the next generation of aircraft engines is high-thrust and high thrust-to-weight ratio engines. The most direct way to improve the engine thrust and thrust-to-weight ratio is to increase the turbine inlet temperature of the aircraft engine. The operating temperature of the blades of an aircraft engine with a thrust-to-weight ratio of 10 has reached 1000℃ after cooling. The increase in the engine operating temperature requires the design of more complex cooling solutions for rotor blades and guide vanes. Therefore, obtaining accurate information on the surface temperature field distribution of turbine blades is crucial for the pre-research and experimental research of aircraft engines. Thermal flux ceramic film temperature sensing is an advanced surface non-destructive temperature monitoring technology that has almost no effect on the structure of components and can achieve substrate surface temperature measurement under ultra-high temperature conditions (>1000℃). Establishing blade surface temperature field distribution data provides a guarantee for the test simulation and real-time damage detection system of the turbine blade service environment, and also provides accurate data for the subsequent optimization and design of aircraft engine materials. It is of great significance for the health monitoring, high performance, high reliability, and long-life safe service of components. As the next generation of aircraft engines develop towards a high thrust-to-weight ratio, the requirements for the operating temperature of temperature sensors are more stringent. Traditional process technologies that sacrifice materials cannot adapt to the requirements of integrated intelligent sensing due to size issues. In addition, the currently mature thermal flux ceramic thin film temperature sensors still have problems such as very slow response speed (response time is in the ms level) and the upper limit of the detection temperature range does not match the actual ambient temperature. Therefore, how to miniaturize the thickness of the device and increase the upper limit of the sensor detection temperature while accelerating the device's response rate to instantaneous heat flux has become a key technical issue that needs to be solved urgently.

[0003] Indium-based oxide semiconductor ceramic materials have good electrical properties and a cubic manganese iron structure with excellent high-temperature stability. They are easy to modify by doping to control the carrier concentration and mobility, thereby maintaining high-temperature stability while accelerating the response rate. They have become the main material for thermal flow ceramic thin film temperature sensors. At present, thermal flow ceramic thin film temperature sensors based on indium oxide mainly focus on the research of tin-doped indium oxide, which increases the carrier concentration and thus the carrier mobility by donor ion doping. However, Sn 4+ Radius (71) and In 3+The large difference in radius (81) can easily cause lattice distortion, increase dislocation density and increase electron scattering, and excessive increase in carrier concentration will also increase electron scattering. Both effects hinder the electron migration rate and increase the response time. Therefore, it is urgent to find a new donor ion to replace Sn ions for doping modification of indium oxide, so as to further improve the electrical properties of the film and thus achieve the performance improvement of the device. Summary of the invention

[0004] The present invention aims at the problems of slow instantaneous heat flow response speed, mismatch between tolerance temperature and development, and difficulty in integrated implementation of the current heat flow ceramic thin film temperature sensor in the field of aviation turbofan engines, and proposes a heat flow ceramic thin film temperature sensor with fast response time and high thermal stability made of indium-based oxide ceramic material and a preparation method thereof. The present invention uses two functional ceramic thin film materials, hafnium-doped indium oxide and pure indium oxide, as the two thermoelectric arms of the temperature sensor, and uses a hard mask combined with a magnetron sputtering process to prepare the temperature sensor, which speeds up the response time of the temperature sensor to instantaneous temperature changes, shortens the response time, and increases the upper limit of the detection temperature.

[0005] In order to solve the above technical problems, the present invention is implemented by the following technical solutions:

[0006] According to one aspect of the present invention, a fast-response heat flux ceramic thin film temperature sensor is provided, comprising a first thermoelectric arm and a second thermoelectric arm, wherein the first thermoelectric arm is made of hafnium-doped indium oxide ceramic thin film, and the second thermoelectric arm is a pure indium oxide ceramic thin film.

[0007] Furthermore, the thickness of the hafnium-doped indium oxide ceramic film is 700 nm to 780 nm.

[0008] Furthermore, the thickness of the pure indium oxide ceramic film is 900nm-980nm.

[0009] According to another aspect of the present invention, there is provided a method for preparing the above-mentioned fast-response thermal flux ceramic thin film temperature sensor, the method comprising:

[0010] (1) After ultrasonic cleaning of the substrate and the mask, they are dried with nitrogen;

[0011] (2) Covering the substrate with a mask and placing it in a sample stage of a magnetron sputtering device;

[0012] (3) placing the target material in a magnetron sputtering device;

[0013] (4) Pump the vacuum degree in the sputtering chamber to 10 -4 Pa or less, and pass argon gas for a period of time;

[0014] (5) adjusting the sputtering gas pressure, sputtering power, and substrate heating temperature to perform magnetron sputtering to obtain a first thermoelectric arm or a second thermoelectric arm;

[0015] (6) Covering the sample obtained in step (5) with a mask and placing it in a sample stage of a magnetron sputtering device;

[0016] (7) placing the target material in a magnetron sputtering device;

[0017] (8) Pump the vacuum degree in the sputtering chamber to 10 -4 Pa or less, and pass argon gas for a period of time;

[0018] (9) adjusting the sputtering gas pressure, sputtering power, and substrate heating temperature to perform magnetron sputtering to obtain a partially stacked first thermoelectric arm and a second thermoelectric arm;

[0019] (10) annealing the sample obtained in step (9);

[0020] Wherein, when the first thermoelectric arm is obtained in step (5): the target material in step (3) is an IHFO ceramic target; the sputtering gas pressure in step (5) is 1Pa, the sputtering power is greater than or equal to 100W, and the substrate heating temperature is 25°C-100°C; the target material in step (7) is an In2O3 ceramic target; the sputtering gas pressure in step (9) is 1Pa, the sputtering power is 60-70W, and the substrate heating temperature is 500°C-600°C;

[0021] Among them, when the second thermoelectric arm is obtained in step (5): the target material in step (3) is an In2O3 ceramic target; the sputtering gas pressure in step (4) is 1Pa, the sputtering power is 60-70W, and the substrate heating temperature is 500℃-600℃; the target material in step (7) is an IHFO ceramic target; the sputtering gas pressure in step (9) is 1Pa, the sputtering power is greater than or equal to 100W, and the substrate heating temperature is 25℃-100℃.

[0022] Furthermore, in step (1), the substrate is an alumina ceramic substrate.

[0023] Furthermore, in step (1), the ultrasonic cleaning is performed by sequentially placing the sample in deionized water, acetone, and alcohol solutions for ultrasonic cleaning, and each ultrasonic cleaning lasts for 30 minutes.

[0024] Furthermore, in step (1), the nitrogen drying time is 20 minutes.

[0025] Furthermore, in step (2), the shape and planar outer dimensions of the mask are the same as those of the substrate, and the mask has a hollow portion inside for forming the first thermoelectric arm or the second thermoelectric arm, and the hollow portion is an inverted "L" shape; the covering mask in step (6) is to flip the mask placed in step (2) horizontally by 180°, so that the first thermoelectric arm or the second thermoelectric arm prepared in step (5) partially overlaps with the mask.

[0026] Furthermore, in step (10), the annealing treatment is carried out in a muffle furnace at a temperature of 1000° C. and an annealing time of 60 min.

[0027] The beneficial effects of the present invention are:

[0028] The present invention selects hafnium to substitute indium oxide. 4+ The ionic radius is 79 and In 3+ The ion radius is very similar, so the effect on the cubic manganese iron ore crystal structure of the indium oxide material is minimal, so the lattice distortion after doping is relatively low, and the thermal stability of the indium oxide structure itself is retained; at the same time, the donor ion doping increases the electron concentration, compensates for the oxygen vacancies in the indium oxide film, reduces the defect density and also reduces the carrier concentration, and realizes the improvement of the carrier mobility rate; by regulating the crystal structure and defect density, the traditional mode of sacrificial material to increase the detection temperature is replaced, the film thickness is reduced, the sensor array integration is promoted, and the high carrier mobility promotes the shortening of the device response time. Studies have shown that the Seebeck coefficient of the temperature sensor prepared by the present invention can reach 104.65μV / ℃, the response time is reduced to 70.54μs, and the operating temperature range is 100℃~1500℃. It can be seen that the present invention promotes the development of sensors towards intelligent integration and provides new ideas for the field of engine integrated high-temperature surface temperature sensing. It is of great significance to the pre-research, whole machine testing, and fault diagnosis of my country's aviation engine components. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the structure of the heat flux ceramic thin film temperature sensor prepared in Example 1 of the present invention.

[0030] Figure 2 Schematic diagram of the structure of a simple reversible hard mask in the preparation of Example 1 of the present invention.

[0031] Figure 3 This is a static calibration working temperature and output thermoelectric potential curve of the heat flux ceramic thin film temperature sensor prepared in Example 1 of the present invention.

[0032] Figure 4 This is a diagram of the dynamic calibration transient response time of the heat flux ceramic thin film temperature sensor prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0033] The present invention is further described in detail below through specific examples. The following examples can enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way.

[0034] Example 1

[0035] like Figure 1 As shown, a heat flux ceramic thin film temperature sensor is prepared according to the following steps:

[0036] (1) Preparation of IHFO thermoelectric arm

[0037] (a) The alumina ceramic substrate was placed in deionized water, acetone, and alcohol solutions in turn and ultrasonically cleaned for 30 min.

[0038] (b) Place the mask in deionized water, acetone, and alcohol solutions in turn and perform ultrasonic cleaning for 30 minutes.

[0039] (c) After the cleaned alumina ceramic substrate and mask in (a) and (b) are dried with nitrogen, the mask is completely overlapped and covers the alumina ceramic substrate, placed in the sample stage of the magnetron sputtering equipment, and the IHFO ceramic target is installed in the magnetron sputtering equipment.

[0040] (d) Pump the vacuum level in the sputtering chamber to 10 -4 Pa and pass argon for 20 min.

[0041] (e) The sputtering gas pressure is adjusted to 1 Pa, the sputtering power is greater than or equal to 100 W, the substrate heating temperature is 25° C.-100° C., and magnetron sputtering is performed to obtain an IHFO single thermoelectric arm sample with a thickness of 750 nm.

[0042] (2) Hard mask and substrate stacking

[0043] (a) If Figure 2 As shown, the shape and size of the mask are the same as those of the substrate, and an inverted "L"-shaped hollow is cut out inside the mask.

[0044] (b) After step (1) (e) is completed, the sample and the mask are taken out, and the mask is flipped horizontally 180° so that the top horizontal portion of the IHFO thermoelectric arm coincides with the top horizontal portion of the inverted "L"-shaped hollow.

[0045] (3) Preparation of In2O3 thermoelectric arms

[0046] (a) Place the sample prepared in step (1) (e) and the mask plate prepared in step (2) (b) on the sample stage of the magnetron sputtering device, and place the In2O3 ceramic target in the magnetron sputtering device.

[0047] (b) Pump the vacuum level in the sputtering chamber to 10 -4 Pa and pass argon for 20 min.

[0048] (c) The sputtering gas pressure is adjusted to 1 Pa, the sputtering power is 60-70 W, the substrate heating temperature is 500° C.-600° C., and magnetron sputtering is performed to obtain a temperature sensor sample having two thermoelectric arms stacked in a specific shape.

[0049] (d) The sample prepared in (2)(c) was placed in a muffle furnace and annealed at 1000°C for 60 min.

[0050] The heat flow functional ceramic thin film temperature sensor prepared in Example 1 was tested for its cross section using a transmission electron microscope, and the thickness of the IHFO thermoelectric arm was measured to be 740nm-760nm, and the thickness of the In2O3 thermoelectric arm was measured to be 940nm-960nm.

[0051] The heat flow functional ceramic thin film temperature sensor prepared in Example 1 was tested by static calibration, and its output thermoelectric potential was as follows: Figure 3 As shown, the operating temperature range is 100℃~1500℃, and the corresponding output thermoelectric potential range is 0~140μV / ℃.

[0052] The heat flow functional ceramic thin film temperature sensor prepared in Example 1 was subjected to dynamic calibration test, and its output thermoelectric potential was as follows: Figure 4 As shown, the response time is less than 100μs. Studies have shown that the Seebeck coefficient of the prepared temperature sensor can reach 104.65μV / ℃, the response time is reduced to 70.54μs, and the operating temperature range is 100℃~1500℃.

[0053] It can be seen that the present invention achieves rapid response and a high upper limit of detection temperature, and promotes the development of sensors towards intelligent integration.

[0054] Although the preferred embodiments of the present invention have been described above in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific embodiments, which are merely illustrative and not restrictive. Under the guidance of the present invention, ordinary technicians in this field can also make many forms of specific changes without departing from the scope of protection of the present invention and the claims, all of which fall within the scope of protection of the present invention.

Claims

1. A fast-response thermal flux ceramic thin film temperature sensor, comprising a first thermoelectric arm and a second thermoelectric arm, characterized in that: The first thermoelectric arm is made of hafnium-doped indium oxide ceramic film, and the second thermoelectric arm is made of pure indium oxide ceramic film.

2. A fast-response thermal flux ceramic thin film temperature sensor according to claim 1, characterized in that: The thickness of the hafnium-doped indium oxide ceramic film is 700nm-780nm.

3. A fast-response thermal flux ceramic thin film temperature sensor according to claim 1, characterized in that: The thickness of the pure indium oxide ceramic film is 900nm-980nm.

4. A method for preparing a fast-response thermal flux ceramic thin film temperature sensor as claimed in any one of claims 1 to 3, characterized in that: The method includes: (1) After ultrasonic cleaning of the substrate and the mask, they are dried with nitrogen; (2) Covering the substrate with a mask and placing it in a sample stage of a magnetron sputtering device; (3) placing the target material in a magnetron sputtering device; (4) Pump the vacuum degree in the sputtering chamber to 10 -4 Pa or less, and pass argon gas for a period of time; (5) adjusting the sputtering gas pressure, sputtering power, and substrate heating temperature to perform magnetron sputtering to obtain a first thermoelectric arm or a second thermoelectric arm; (6) Covering the sample obtained in step (5) with a mask and placing it in a sample stage of a magnetron sputtering device; (7) placing the target material in a magnetron sputtering device; (8) Pump the vacuum degree in the sputtering chamber to 10 -4 Pa or less, and pass argon gas for a period of time; (9) adjusting the sputtering gas pressure, sputtering power, and substrate heating temperature to perform magnetron sputtering to obtain a partially stacked first thermoelectric arm and a second thermoelectric arm; (10) annealing the sample obtained in step (9); Wherein, when the first thermoelectric arm is obtained in step (5): the target material in step (3) is an IHFO ceramic target; the sputtering gas pressure in step (5) is 1Pa, the sputtering power is greater than or equal to 100W, and the substrate heating temperature is 25°C-100°C; the target material in step (7) is an In2O3 ceramic target; the sputtering gas pressure in step (9) is 1Pa, the sputtering power is 60-70W, and the substrate heating temperature is 500°C-600°C; Among them, when the second thermoelectric arm is obtained in step (5): the target material in step (3) is an In2O3 ceramic target; the sputtering gas pressure in step (4) is 1Pa, the sputtering power is 60-70W, and the substrate heating temperature is 500℃-600℃; the target material in step (7) is an IHFO ceramic target; the sputtering gas pressure in step (9) is 1Pa, the sputtering power is greater than or equal to 100W, and the substrate heating temperature is 25℃-100℃.

5. The method for preparing a fast-response thermal flux ceramic thin film temperature sensor according to claim 4, characterized in that: In step (1), the substrate is an alumina ceramic substrate.

6. The method for preparing a fast-response thermal flux ceramic thin film temperature sensor according to claim 4, characterized in that: In step (1), the ultrasonic cleaning is performed by sequentially placing the sample in deionized water, acetone, and alcohol solutions for ultrasonic cleaning, with each ultrasonic cleaning lasting 30 minutes.

7. The method for preparing a fast-response thermal flux ceramic thin film temperature sensor according to claim 4, characterized in that: In step (1), the nitrogen drying time is 20 minutes.

8. The method for preparing a fast-response thermal flux ceramic thin film temperature sensor according to claim 4, characterized in that: In step (2), the shape and plane outer dimensions of the mask are the same as those of the substrate, and the mask has a hollow portion inside for forming the first thermoelectric arm or the second thermoelectric arm, and the hollow portion is an inverted "L" shape; the covering mask in step (6) is to flip the mask placed in step (2) horizontally by 180°, so that the first thermoelectric arm or the second thermoelectric arm prepared in step (5) partially overlaps with the mask.

9. The method for preparing a fast-response thermal flux ceramic thin film temperature sensor according to claim 4, characterized in that: In step (10), the annealing treatment is carried out in a muffle furnace, the annealing temperature is 1000° C., and the annealing time is 60 min.

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