An electromagnetic interference resistant film thermocouple with a double-sided shielding structure and a preparation method thereof

Abstract

The application discloses a kind of double-sided shielding structure's anti-electromagnetic interference film thermocouple and preparation method thereof, adopt the structure of double-sided shielding to solve the technical problem that existing film thermocouple output signal is interfered with by electricity and leads to low signal precision, including ceramic substrate and ceramic substrate on positive electrode sensitive layer film, negative electrode sensitive layer film, insulating layer film on sensitive layer film, shielding layer film on the back of ceramic substrate, shielding layer film on insulating layer film.Adopt magnetron sputtering technology, electron beam evaporation technology and silk screen printing technology etc., prepare two different thermoelectric electrode sensitive layer film and insulating layer film, shielding layer film on ceramic substrate.The prepared double-sided shielding film thermocouple can be used for temperature measurement in electromagnetic environment, reduce interference introduction, improve the precision of film thermocouple output signal.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of thin film sensors, and particularly relates to an anti-electromagnetic interference thin film thermocouple with a double-sided shielding structure and a preparation method thereof. BACKGROUND

[0002] The thin film thermocouple is a temperature sensing element, directly measures temperature, converts a temperature signal into a thermoelectric electromotive force signal, and converts the temperature signal into the temperature of a measured medium through an electrical instrument.

[0003] However, when the thin film thermocouple is used to collect and monitor temperature signals, the thin film thermocouple may encounter electromagnetic interference during detection with the increase of various electromagnetic signals on site. Changes in electric field and magnetic field are easy to induce voltage on the thin film thermocouple, leading to signal distortion. The stability and precision of the output signal of the thin film thermocouple are greatly affected, resulting in unreliable temperature measurement of the thin film thermocouple, and thus the user is inconvenient to use. SUMMARY

[0004] The technical problem to be solved by the application is to provide an anti-electromagnetic interference thin film thermocouple with a double-sided shielding structure and a preparation method thereof, which realizes temperature measurement in an electromagnetic environment, reduces the introduction of interference, and improves temperature measurement precision, to solve the technical problem of low signal precision caused by electromagnetic interference on the output signal of the existing thin film thermocouple.

[0005] The application adopts the following technical scheme:

[0006] The anti-electromagnetic interference thin film thermocouple with a double-sided shielding structure comprises a ceramic substrate, a first shielding layer is arranged on the lower surface of the ceramic substrate, a positive sensitive layer thin film and a negative sensitive layer thin film are arranged on the upper surface of the ceramic substrate, the positive sensitive layer thin film and the negative sensitive layer thin film are symmetrically arranged and in contact with each other, an insulating layer is arranged on the upper surface of the positive sensitive layer thin film, the negative sensitive layer thin film and the ceramic substrate, and a second shielding layer is arranged on the insulating layer.

[0007] Specifically, one end of the positive sensitive layer thin film is connected to a left cold end, one end of the negative sensitive layer thin film is connected to a right cold end, the left cold end and the right cold end are connected through a connecting compensation lead wire to lead out a thermoelectric potential, and the other end of the positive sensitive layer thin film and the other end of the negative sensitive layer thin film are overlapped to form a hot node temperature sensing area.

[0008] Specifically, the thickness of the positive sensitive layer thin film and the negative sensitive layer thin film is 20-100 μm.

[0009] Specifically, the length of the first shielding layer is the same as that of the ceramic substrate, the length of the insulating layer is the same as that of the second shielding layer, and the thickness of the second shielding layer is 20-100 μm.

[0010] Specifically, the first shielding layer is connected with the second shielding layer in ground.

[0011] Another technical solution of the application is a preparation method of a double-sided shielding structure anti-electromagnetic interference thin film thermocouple, comprising the following steps:

[0012] The positive sensitive layer thin film and the negative sensitive layer thin film are prepared by drying and annealing treatment of the upper surface of the ceramic substrate using indium tin oxide slurry and indium oxide slurry respectively;

[0013] The first shielding layer is prepared by drying and annealing treatment of the lower surface of the ceramic substrate using nickel-coated copper slurry;

[0014] The insulating layer is prepared by drying and annealing treatment of the upper surface of the positive sensitive layer thin film, the negative sensitive layer thin film and the ceramic substrate using aluminum oxide slurry; and the second shielding layer is prepared by drying and annealing treatment of the upper surface of the insulating layer using nickel-coated copper slurry;

[0015] The double-sided shielding thin film thermocouple is prepared by annealing treatment in vacuum or inert atmosphere.

[0016] Specifically, the drying temperature for preparing the positive sensitive layer thin film and the negative sensitive layer thin film is 60-80℃, the annealing temperature is 200-350℃, the time is 15-180min, and the indium tin oxide powder is mixed by 90% indium oxide and 10% tin oxide.

[0017] Specifically, the drying temperature for preparing the insulating layer is 60-80℃, the annealing temperature is 150-350℃, the time is 15-120min, and the particle size of the aluminum oxide powder in the aluminum oxide slurry is 30-100nm.

[0018] Specifically, the drying temperature for preparing the first shielding layer and the second shielding layer is 60-80℃.

[0019] Specifically, the annealing temperature for preparing the double-sided shielding thin film thermocouple is 100-350℃, and the time is 15-180min.

[0020] Compared with the prior art, the application has at least the following beneficial effects:

[0021] The present invention discloses an electromagnetic interference-resistant thin-film thermocouple with a double-sided shielding structure. The insulating layer on the positive and negative sensitive films is used to prevent the sensitive films of the thin-film thermocouple from being directly connected to the shielding layer, which would cause temperature measurement errors and achieve effective electrical isolation. The substrate on which the thin-film thermocouple is arranged is made of a high-temperature resistant ceramic material, which can play an insulating role. Therefore, the provision of an insulating layer on the back side of the substrate can be omitted, simplifying the preparation process of the thin-film thermocouple and reducing the impact on the dynamic response time of the thin-film thermocouple. The upper and lower sides of the thin-film thermocouple are shielded by shielding layers, which can fully wrap the thin-film thermocouple, reduce the introduction of interference in the electromagnetic field environment, and effectively improve the shielding effect.

[0022] Furthermore, the left and right cold ends of the thin film thermocouple are connected through leads to output a voltage signal of the thin film thermocouple, and the voltage signal is obtained through a data acquisition device.

[0023] Furthermore, the positive and negative electrode sensitive films can be prepared by various methods such as screen printing technology, magnetron sputtering technology, electron beam evaporation technology, etc., with a thickness of 20 to 100 μm, which can ensure that the film can effectively transport electrons. At the same time, the thinner the film thickness, the faster the dynamic response speed of the thin film thermocouple.

[0024] Furthermore, the length of the first shielding layer is the same as that of the ceramic substrate to achieve complete wrapping of the back side and prevent the introduction of external interference. The insulating layer on the sensitive film is the same length as the second shielding layer and is slightly shorter than the sensitive layer film, which facilitates the lead connection of the sensitive layer film to output thermoelectric signals. The insulating layer and the second shielding layer are the same length to ensure wrapping above the thin film thermocouple and reduce the introduction of external interference. The second shielding layer can be prepared by various technologies such as screen printing technology, magnetron sputtering technology, and electron beam evaporation technology, with a thickness of 20 to 100 μm. The smaller the thickness of the second shielding layer, the smaller the impact on the heat transfer process and the smaller the impact on the dynamic response speed of the thin film thermocouple.

[0025] Furthermore, the first shielding layer and the second shielding layer are properly shielded and grounded, which can reduce the electromagnetic field intensity within the shielding layer and reduce the introduction of external electromagnetic interference, which is beneficial to improving the temperature measurement accuracy of the thin film thermocouple in an electromagnetic environment.

[0026] A method for preparing an anti-electromagnetic interference thin film thermocouple with a double-sided shielding structure, wherein positive and negative sensitive layer films, an insulating layer film, a first shielding layer film, and a second shielding layer film are prepared separately, and are dried and heat-treated at appropriate temperatures and atmospheres to improve the quality of the films and the performance of each layer of the films.

[0027] Furthermore, the positive electrode sensitive film and the negative electrode sensitive film are preliminarily dried at 60-80°C and annealed at 200-350°C for 15-180 minutes. The subsequent annealing treatment is conducive to further growth of the film, reduces the internal stress in the film caused by lattice mismatch, improves the film microstructure, reduces defects in the film, improves the stability and uniformity of the film, and improves the working performance of the thin film thermocouple.

[0028] Furthermore, the insulating layer film is preliminarily dried at 60-80°C and annealed at 150-350°C for 15-120 minutes. The subsequent annealing treatment is conducive to recrystallization of the film, making the film crystal structure more complete, and improving the quality of the insulating layer film and the insulating performance of the insulating layer.

[0029] Furthermore, the first shielding layer film and the second shielding layer film are preliminarily dried at 60-80° C. to facilitate subsequent heat treatment.

[0030] Furthermore, after the first shielding layer film and the second shielding layer film are dried at 60-80°C, they are annealed at 100-350°C for 15-180 minutes. The subsequent annealing treatment is conducive to the recrystallization of the film, making the crystal structure of the film more complete, and improving the quality of the shielding layer film and the conductivity and shielding performance of the shielding layer.

[0031] In summary, symmetrical thin-film thermocouples are prepared on ceramic substrates through screen printing and other technologies to realize temperature perception and convert it into voltage signal output; by reasonably setting the structural layout of each film layer and adopting appropriate heat treatment process, the thermoelectric properties of thin-film thermocouples, the insulation properties of the insulating layer, the shielding properties of the shielding layer, etc. can be improved, the interference introduced in the electromagnetic environment can be reduced, and the accuracy of temperature measurement of thin-film thermocouples in the electromagnetic environment can be improved, so that thin-film thermocouples can be used for accurate temperature measurement in the electromagnetic environment.

[0032] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 is a cross-sectional view of the anti-electromagnetic interference thin film thermocouple of the present invention;

[0034] Figure 2 It is a left side view of the anti-electromagnetic interference thin film thermocouple of the present invention;

[0035] Figure 3 It is a right side view of the anti-electromagnetic interference thin film thermocouple of the present invention;

[0036] Figure 4 A bottom view of the anti-electromagnetic interference thin film thermocouple of the present invention;

[0037] Figure 5It is a top view of the anti-electromagnetic interference thin film thermocouple of the present invention.

[0038] Among them: 1. Positive electrode sensitive layer film; 2. Negative electrode sensitive layer film; 3. Ceramic substrate; 4. First shielding layer; 5. Insulation layer; 6. Second shielding layer; 7. Hot node temperature sensing area; 8. Cold end lead connection area; 9. Left cold end; 10. Right cold end. DETAILED DESCRIPTION

[0039] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0040] In the description of the present invention, it should be understood that the terms "center," "longitudinal," "lateral," "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inside," "outside," "one side," "one end," and "one side" and the like, indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings and are intended only to facilitate the description of the present invention and simplify the description. They do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed, or operate in a specific orientation, and therefore should not be construed as limiting the present invention. Furthermore, in the description of the present invention, unless otherwise specified, "a plurality" means two or more.

[0041] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "one side", "one end", "one side" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0042] It will be understood that when used in this specification and the appended claims, the terms “comprises” and “comprising” indicate the presence of described features, integers, steps, operations, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0043] It should also be understood that the terms used in the present specification are only for the purpose of describing particular embodiments and are not intended to limit the present invention. As used in the present specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms unless the context clearly indicates otherwise.

[0044] It should be further understood that the term "and / or" used in the present description and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

[0045] The accompanying drawings illustrate various schematic diagrams of structures according to embodiments disclosed herein. These figures are not drawn to scale; for clarity, some details are exaggerated and some details may be omitted. The shapes of the various regions and layers shown in the figures, as well as their relative sizes and positional relationships, are merely exemplary and may deviate in practice due to manufacturing tolerances or technical limitations. Those skilled in the art may design regions / layers with different shapes, sizes, and relative positions as needed.

[0046] The present invention provides an electromagnetic interference-resistant thin-film thermocouple with a double-sided shielding structure and a preparation method thereof. Magnetron sputtering technology, electron beam evaporation technology and screen printing technology are used to prepare two different positive-electrode sensitive layer films and negative-electrode sensitive layer films, as well as an insulating layer film and a second shielding layer on a ceramic substrate. The prepared double-sided shielding thin-film thermocouple can be used for temperature measurement in an electromagnetic environment, reduces interference introduction, and improves the accuracy of the thin-film thermocouple output signal.

[0047] See also Figure 1 The present invention provides an anti-electromagnetic interference thin film thermocouple with a double-sided shielding structure, comprising a positive electrode sensitive layer film 1, a negative electrode sensitive layer film 2, a ceramic substrate 3, a first shielding layer 4, an insulating layer 5 and a second shielding layer 6; the positive electrode sensitive layer film 1 and the negative electrode sensitive layer film 2 are arranged on the upper surface of the ceramic substrate 3, and the first shielding layer 4 is arranged on the lower surface of the ceramic substrate 3; the insulating layer 5 is arranged on the upper surfaces of the positive electrode sensitive layer film 1, the negative electrode sensitive layer film 2 and the ceramic substrate 3, and the second shielding layer 6 is arranged on the upper surface of the insulating layer 5.

[0048] See also Figure 2One end of the positive electrode sensitive layer film 1 is connected to the left cold end 9, and one end of the negative electrode sensitive layer film 2 is connected to the right cold end 10. The left cold end 9 and the right cold end 10 are arranged in the cold end lead connection area 8. The other end of the positive electrode sensitive layer film 1 and the other end of the negative electrode sensitive layer film 2 overlap with each other to form a hot node temperature sensing area 7.

[0049] The left cold end 9 and the right cold end 10 are connected to a compensation wire to lead out the thermoelectric potential.

[0050] The thickness of the positive electrode sensitive layer film 1 is 20 to 100 μm; the thickness of the negative electrode sensitive layer film 2 is 20 to 100 μm.

[0051] The positive electrode sensitive layer film 1 is made of indium tin oxide, and the negative electrode sensitive layer film 2 is made of indium oxide. Indium oxide and indium tin oxide are selected as thermoelectric materials, and symmetrical thin film thermocouples are prepared on a ceramic substrate using screen printing technology or magnetron sputtering technology. Temperature is sensed and converted into a voltage signal output. By rationally designing the film layer structure, temperature measurement in an electromagnetic environment can be achieved.

[0052] The thickness of the insulating layer 5 is 20 to 100 μm; the insulating layer 5 is made of low-conductivity materials, including but not limited to Al2O3, with high thermal conductivity, little effect on the heat transfer process, and can prevent the thermocouple sensitive layer and the shielding layer from being conductive, resulting in voltage signal loss and interference.

[0053] The thickness of the second shielding layer 6 is 20 to 100 μm; the first shielding layer 4 and the second shielding layer 6 are made of high conductivity materials, including but not limited to copper and nickel-clad copper films, which can shield electromagnetic signals, improve the accuracy of thin film thermocouple thermoelectric signals, and reduce the introduction of interference.

[0054] See also Figure 3 and Figure 5 The positive electrode sensitive layer film 1 and the negative electrode sensitive layer film 2 are arranged on the ceramic substrate 3, an insulating layer 5 is prepared on the positive electrode sensitive layer film 1, the negative electrode sensitive layer film 2 and the ceramic substrate 3, and a second shielding layer 6 is prepared on the insulating layer 5. The insulating layer 5 and the second shielding layer 6 have the same length and are shorter than the length of the back of the sensitive layer, reserving a position for the lead.

[0055] See also Figure 4 A first shielding layer 4 is prepared on the back of the ceramic substrate 3. The first shielding layer 4 on the back of the ceramic substrate 3 has the same length as the ceramic substrate 3 to improve the shielding effect.

[0056] The first shielding layer 4 and the second shielding layer 6 are grounded to reduce the introduction of interference.

[0057] The present invention provides a method for preparing an electromagnetic interference-resistant thin-film thermocouple with a double-sided shielding structure, comprising the following steps:

[0058] S1, cleaning the ceramic substrate 3, and then drying it for standby use;

[0059] The ceramic substrate 3 was ultrasonically cleaned in an acetone solution for 10 minutes and in an anhydrous ethanol solution for 10 minutes, then rinsed with deionized water, dried with nitrogen, and then dried.

[0060] S2. Adding terpineol, epoxy resin, and polyetheramine to indium oxide powder and indium tin oxide powder, respectively, and stirring to obtain indium oxide slurry and indium tin oxide slurry;

[0061] The indium tin oxide powder is a mixture of 90% indium oxide and 10% tin oxide.

[0062] S3, using screen printing technology, using a positive electrode screen printing mask to print the indium tin oxide slurry prepared in step S2 on the upper surface of the ceramic substrate 3 obtained in step S1, and placing it on a hot platform at a temperature of 60-80° C. for drying to obtain an indium tin oxide thin film as the positive electrode sensitive layer thin film 1;

[0063] S4. Using screen printing technology, the indium oxide slurry prepared in step S2 is printed on the upper surface of the ceramic substrate 3 obtained in step S3 using a negative electrode screen printing mask, and then placed on a hot platform at a temperature of 60-80° C. for drying to obtain an indium oxide thin film as the negative electrode sensitive layer thin film 2;

[0064] S5, annealing the ceramic substrate 3 processed in step S4 in air to increase the carrier concentration and the density of the film microstructure, thereby obtaining a thermocouple based on the indium oxide-indium tin oxide film;

[0065] The annealing temperature is 200-350° C., and the annealing time is 15-180 min.

[0066] S6. Add terpineol, epoxy resin, and polyetheramine to the alumina powder respectively, and stir to obtain an alumina slurry;

[0067] The particle size of the aluminum oxide powder is 30 to 100 nm.

[0068] S7, using screen printing technology, using an insulating layer screen printing mask to print the aluminum oxide slurry prepared in step S6 on the upper surface of the thermocouple based on the indium oxide-indium tin oxide film obtained in step S5, and placing it on a hot platform at a temperature of 60-80° C. for drying, thereby preparing an aluminum oxide insulating layer film on the thermocouple based on the indium oxide-indium tin oxide film;

[0069] S8, annealing the alumina insulating layer film obtained in step S7 in an air atmosphere at an annealing temperature of 150-350℃ for 15-120min to prepare an insulating layer 5 on the upper surface of the thermocouple based on the indium oxide-indium tin oxide film;

[0070] S9, adding epoxy resin, polyether amine, glycerol and propylene glycol into the nickel-coated copper powder respectively, and stirring to obtain a nickel-coated copper paste;

[0071] S10, printing the nickel-coated copper paste prepared in step S9 on the insulating layer 5 obtained in step S8 by using a shielding layer screen printing mask, and placing the same on a hot platform at a temperature of 60-80℃ for drying treatment to prepare a second shielding layer 6 on the insulating layer 5;

[0072] S11, printing the nickel-coated copper paste prepared in step S9 on the lower surface of the thermocouple based on the indium oxide-indium tin oxide film obtained in step S10 by using a shielding layer screen printing mask, and placing the same on a hot platform at a temperature of 60-80℃ for drying treatment to prepare a first shielding layer 4;

[0073] S12, annealing the thermocouple based on the indium oxide-indium tin oxide film treated in step S11 in a vacuum or inert atmosphere to improve the conductivity of the shielding layer, the annealing temperature being 100-350℃ and the annealing time being 15-180min to obtain a double-sided shielding film thermocouple.

[0074] The inert atmosphere is vacuum or N2.

[0075] To make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings herein can be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present application.

[0076] Embodiment 1

[0077] A preparation method of an electromagnetic interference resistant thin film thermocouple with a double-sided shielding structure, comprising the following steps:

[0078] S1. Ultrasonic cleaning of the ceramic substrate in acetone solution for 10 min, ultrasonic cleaning in anhydrous ethanol solution for 10 min, then rinsing with deionized water, drying with nitrogen, and drying for later use;

[0079] S2. Adding terpineol, epoxy resin, and polyetheramine to indium oxide powder and indium tin oxide powder, respectively, and stirring to obtain indium oxide slurry and indium tin oxide slurry, wherein the indium tin oxide powder is a mixture of 90% indium oxide and 10% tin oxide;

[0080] S3, using screen printing technology, using a positive electrode screen printing mask to print the indium tin oxide slurry prepared in step S2 on the upper surface of the ceramic substrate obtained in step S1, and placing it on a hot platform at a temperature of 60° C. for drying to obtain an indium tin oxide thin film as the positive electrode sensitive layer thin film;

[0081] S4. Using screen printing technology, the indium oxide slurry prepared in step S2 is printed on the upper surface of the ceramic substrate obtained in step S3 using a negative electrode screen printing mask, and then placed on a hot platform at a temperature of 60° C. for drying to obtain an indium oxide thin film as the negative electrode sensitive layer thin film;

[0082] S5, annealing the ceramic substrate processed in step S4 in air at a controlled annealing temperature of 200° C. for 15 minutes to increase the carrier concentration and the density of the film microstructure, thereby obtaining a thermocouple based on the indium oxide-indium tin oxide film;

[0083] S6. Add terpineol, epoxy resin, and polyetheramine to alumina powder with a particle size of 30 nm, respectively, and stir to obtain alumina slurry;

[0084] S7, using screen printing technology, using an insulating layer screen printing mask to print the aluminum oxide slurry prepared in step S6 on the upper surface of the thermocouple obtained in step S5, and placing it on a hot platform at a temperature of 60° C. for drying, thereby preparing an aluminum oxide insulating layer film on the indium oxide-indium tin oxide film-based thermocouple;

[0085] S8, annealing the aluminum oxide insulating layer obtained in step S7 at an annealing temperature of 150° C. for 15 minutes in an air atmosphere to prepare an insulating layer on the upper surface of the indium oxide-indium tin oxide film-based thermocouple;

[0086] S9, adding epoxy resin, polyetheramine, glycerin, and propylene glycol to the nickel-coated copper powder respectively, and stirring to obtain a nickel-coated copper slurry;

[0087] S10, using screen printing technology, using a shielding layer screen printing mask to print the nickel-coated copper paste prepared in step S9 on the insulating layer obtained in step S8, and placing it on a hot platform at a temperature of 60° C. for drying, thereby preparing a second shielding layer on the insulating layer;

[0088] S11, using screen printing technology, using a shielding layer screen printing mask to print the nickel-coated copper paste prepared in step S9 on the lower surface of the thermocouple based on indium oxide-indium tin oxide film obtained in step S10, and placing it on a hot platform at a temperature of 60° C. for drying to prepare a first shielding layer;

[0089] S12. Annealing the indium oxide-indium tin oxide thin film thermocouple obtained in step S11 at 100° C. for 15 minutes in a vacuum or inert atmosphere to obtain a double-sided shielded thin film thermocouple.

[0090] Temperature perception is achieved by symmetrically preparing indium tin oxide-indium oxide sensitive films on a ceramic substrate; by rationally arranging the structural layout of each layer of the film, a thin film thermocouple with a double-sided shielding structure is obtained to reduce the introduction of external interference; by adopting appropriate heat treatment process, heat treatment time and heat treatment atmosphere, the relevant performance of each film layer is improved to achieve accurate temperature measurement in an electromagnetic environment.

[0091] Example 2

[0092] A method for preparing an electromagnetic interference-resistant thin-film thermocouple with a double-sided shielding structure, comprising the following steps:

[0093] S1. Ultrasonic cleaning of the ceramic substrate in acetone solution for 10 min, ultrasonic cleaning in anhydrous ethanol solution for 10 min, then rinsing with deionized water, drying with nitrogen, and drying for later use;

[0094] S2. Adding terpineol, epoxy resin, and polyetheramine to indium oxide powder and indium tin oxide powder, respectively, and stirring to obtain indium oxide slurry and indium tin oxide slurry, wherein the indium tin oxide powder is a mixture of 90% indium oxide and 10% tin oxide;

[0095] S3. Using screen printing technology, the indium tin oxide slurry prepared in step S2 is printed on the upper surface of the ceramic substrate obtained in step S1 using a positive electrode screen printing mask, and the slurry is placed on a hot plate at a temperature of 65° C. for drying to obtain an indium tin oxide thin film as the positive electrode sensitive layer thin film;

[0096] S4. Using screen printing technology, the indium oxide slurry prepared in step S2 is printed on the upper surface of the ceramic substrate obtained in step S3 using a negative electrode screen printing mask, and then placed on a hot platform at a temperature of 65° C. for drying to obtain an indium oxide thin film as the negative electrode sensitive layer thin film;

[0097] S5, annealing the ceramic substrate processed in step S4 in air at a controlled annealing temperature of 250° C. for 30 minutes to increase the carrier concentration and the density of the film microstructure, thereby obtaining a thermocouple based on the indium oxide-indium tin oxide film;

[0098] S6. Add terpineol, epoxy resin, and polyetheramine to alumina powder with a particle size of 40 nm, respectively, and stir to obtain alumina slurry;

[0099] S7, using screen printing technology, using an insulating layer screen printing mask to print the aluminum oxide slurry prepared in step S6 on the upper surface of the thermocouple obtained in step S5, and placing it on a hot platform at a temperature of 65° C. for drying, thereby preparing an aluminum oxide insulating layer film on the indium oxide-indium tin oxide film-based thermocouple;

[0100] S8, annealing the aluminum oxide insulating layer obtained in step S7 at a temperature of 200° C. for 30 minutes in an air atmosphere to prepare an insulating layer on the upper surface of the indium oxide-indium tin oxide film-based thermocouple;

[0101] S9, adding epoxy resin, polyetheramine, glycerin, and propylene glycol to the nickel-coated copper powder respectively, and stirring to obtain a nickel-coated copper slurry;

[0102] S10, using screen printing technology, using a shielding layer screen printing mask to print the nickel-coated copper paste prepared in step S9 on the insulating layer obtained in step S8, and placing it on a hot platform at a temperature of 65° C. for drying, thereby preparing a second shielding layer on the insulating layer;

[0103] S11, using screen printing technology, using a shielding layer screen printing mask to print the nickel-coated copper paste prepared in step S9 on the lower surface of the thermocouple based on indium oxide-indium tin oxide film obtained in step S10, and placing it on a hot platform at a temperature of 65° C. for drying to prepare a first shielding layer;

[0104] S12. Annealing the indium oxide-indium tin oxide thin film thermocouple obtained in step S11 at 200° C. for 30 minutes in a vacuum or inert atmosphere to obtain a double-sided shielded thin film thermocouple.

[0105] Temperature perception is achieved by symmetrically preparing indium tin oxide-indium oxide sensitive films on a ceramic substrate; by rationally arranging the structural layout of each layer of the film, a thin film thermocouple with a double-sided shielding structure is obtained to reduce the introduction of external interference; by adopting appropriate heat treatment process, heat treatment time and heat treatment atmosphere, the relevant performance of each film layer is improved to achieve accurate temperature measurement in an electromagnetic environment.

[0106] Example 3

[0107] A preparation method of an electromagnetic interference resistant film thermocouple with a double-sided shielding structure, comprising the following steps:

[0108] S1, the ceramic substrate is sequentially cleaned in an acetone solution for 10 minutes, cleaned in an anhydrous ethanol solution for 10 minutes, rinsed with deionized water, dried with nitrogen, and then dried for standby use;

[0109] S2, terpineol, epoxy resin, and polyether amine are added to indium oxide powder and indium tin oxide powder respectively, and stirring is performed to obtain indium oxide slurry and indium tin oxide slurry, and the indium tin oxide powder is obtained by mixing 90% indium oxide and 10% tin oxide;

[0110] S3, a screen printing technology is used, the indium tin oxide slurry prepared in step S2 is printed on the upper surface of the ceramic substrate obtained in step S1 by using a positive electrode screen printing mask, and the ceramic substrate is placed on a hot platform at a temperature of 70 DEG C for drying, so as to obtain an indium tin oxide film as a positive electrode sensitive layer film;

[0111] S4, a screen printing technology is used, the indium oxide slurry prepared in step S2 is printed on the upper surface of the ceramic substrate obtained in step S3 by using a negative electrode screen printing mask, and the ceramic substrate is placed on a hot platform at a temperature of 70 DEG C for drying, so as to obtain an indium oxide film as a negative electrode sensitive layer film;

[0112] S5, the ceramic substrate treated in step S4 is annealed in air at an annealing temperature of 275 DEG C for 60 minutes, so as to improve the carrier concentration and the microstructure density of the film, and obtain an indium oxide-indium tin oxide film based thermocouple;

[0113] S6, terpineol, epoxy resin, and polyether amine are added to aluminum oxide powder with a particle size of 60 nm respectively, and stirring is performed to obtain aluminum oxide slurry;

[0114] S7, a screen printing technology is used, the aluminum oxide slurry prepared in step S6 is printed on the upper surface of the thermocouple obtained in step S5 by using an insulating layer screen printing mask, and the thermocouple is placed on a hot platform at a temperature of 70 DEG C for drying, so as to obtain an aluminum oxide insulating layer film on the indium oxide-indium tin oxide film based thermocouple;

[0115] S8, the aluminum oxide insulating layer film obtained in step S7 is annealed in air at an annealing temperature of 250 DEG C for 60 minutes, so as to obtain an insulating layer on the upper surface of the indium oxide-indium tin oxide film based thermocouple;

[0116] S9, epoxy resin, polyether amine, glycerol, and propylene glycol are added to nickel-coated copper powder respectively, and stirring is performed to obtain nickel-coated copper slurry;

[0117] S10, using screen printing technology, using a shielding layer screen printing mask to print the nickel-coated copper paste prepared in step S9 on the insulating layer obtained in step S8, and placing it on a hot platform at a temperature of 70° C. for drying, thereby preparing a second shielding layer on the insulating layer;

[0118] S11, using screen printing technology, using a shielding layer screen printing mask to print the nickel-coated copper paste prepared in step S9 on the lower surface of the thermocouple based on indium oxide-indium tin oxide film obtained in step S10, and placing it on a hot platform at a temperature of 70° C. for drying to prepare a first shielding layer;

[0119] S12. Annealing the indium oxide-indium tin oxide thin film thermocouple obtained in step S11 at 250° C. for 60 minutes in a vacuum or inert atmosphere to obtain a double-sided shielded thin film thermocouple.

[0120] Temperature perception is achieved by symmetrically preparing indium tin oxide-indium oxide sensitive films on a ceramic substrate; by rationally arranging the structural layout of each layer of the film, a thin film thermocouple with a double-sided shielding structure is obtained to reduce the introduction of external interference; by adopting appropriate heat treatment process, heat treatment time and heat treatment atmosphere, the relevant performance of each film layer is improved to achieve accurate temperature measurement in an electromagnetic environment.

[0121] Example 4

[0122] A method for preparing an electromagnetic interference-resistant thin-film thermocouple with a double-sided shielding structure, comprising the following steps:

[0123] S1. Ultrasonic cleaning of the ceramic substrate in acetone solution for 10 min, ultrasonic cleaning in anhydrous ethanol solution for 10 min, then rinsing with deionized water, drying with nitrogen, and drying for later use;

[0124] S2. Adding terpineol, epoxy resin, and polyetheramine to indium oxide powder and indium tin oxide powder, respectively, and stirring to obtain indium oxide slurry and indium tin oxide slurry, wherein the indium tin oxide powder is a mixture of 90% indium oxide and 10% tin oxide;

[0125] S3. Using screen printing technology, the indium tin oxide slurry prepared in step S2 is printed on the upper surface of the ceramic substrate obtained in step S1 using a positive electrode screen printing mask, and the slurry is placed on a hot plate at a temperature of 75° C. for drying to obtain an indium tin oxide thin film as the positive electrode sensitive layer thin film;

[0126] S4. Using screen printing technology, the indium oxide slurry prepared in step S2 is printed on the upper surface of the ceramic substrate obtained in step S3 using a negative electrode screen printing mask, and then placed on a hot platform at a temperature of 75° C. for drying to obtain an indium oxide thin film as the negative electrode sensitive layer thin film;

[0127] S5, annealing the ceramic substrate processed in step S4 in air at a controlled annealing temperature of 300° C. for 120 minutes to increase the carrier concentration and the density of the film microstructure, thereby obtaining a thermocouple based on the indium oxide-indium tin oxide film;

[0128] S6. Add terpineol, epoxy resin, and polyetheramine to alumina powder with a particle size of 80 nm, respectively, and stir to obtain alumina slurry;

[0129] S7. Using screen printing technology, the aluminum oxide slurry prepared in step S6 is printed on the upper surface of the thermocouple obtained in step S5 using an insulating layer screen printing mask, and the slurry is placed on a hot plate at a temperature of 75° C. for drying, thereby preparing an aluminum oxide insulating layer film on the indium oxide-indium tin oxide film-based thermocouple;

[0130] S8, annealing the aluminum oxide insulating layer obtained in step S7 at an annealing temperature of 300° C. for 90 minutes in an air atmosphere to prepare an insulating layer on the upper surface of the indium oxide-indium tin oxide film-based thermocouple;

[0131] S9, adding epoxy resin, polyetheramine, glycerin, and propylene glycol to the nickel-coated copper powder respectively, and stirring to obtain a nickel-coated copper slurry;

[0132] S10, using screen printing technology, using a shielding layer screen printing mask to print the nickel-coated copper paste prepared in step S9 on the insulating layer obtained in step S8, and placing it on a hot platform at a temperature of 75° C. for drying, thereby preparing a second shielding layer on the insulating layer;

[0133] S11, using screen printing technology, using a shielding layer screen printing mask to print the nickel-coated copper paste prepared in step S9 on the lower surface of the thermocouple based on indium oxide-indium tin oxide film obtained in step S10, and placing it on a hot platform at a temperature of 75° C. for drying to prepare a first shielding layer;

[0134] S12. Annealing the indium oxide-indium tin oxide thin film thermocouple obtained in step S11 at 300° C. for 120 min in a vacuum or inert atmosphere to obtain a double-sided shielded thin film thermocouple.

[0135] Temperature perception is achieved by symmetrically preparing indium tin oxide-indium oxide sensitive films on a ceramic substrate; by rationally arranging the structural layout of each layer of the film, a thin film thermocouple with a double-sided shielding structure is obtained to reduce the introduction of external interference; by adopting appropriate heat treatment process, heat treatment time and heat treatment atmosphere, the relevant performance of each film layer is improved to achieve accurate temperature measurement in an electromagnetic environment.

[0136] Example 5

[0137] A method for preparing an electromagnetic interference-resistant thin-film thermocouple with a double-sided shielding structure, comprising the following steps:

[0138] S1. Ultrasonic cleaning of the ceramic substrate in acetone solution for 10 min, ultrasonic cleaning in anhydrous ethanol solution for 10 min, then rinsing with deionized water, drying with nitrogen, and drying for later use;

[0139] S2. Adding terpineol, epoxy resin, and polyetheramine to indium oxide powder and indium tin oxide powder, respectively, and stirring to obtain indium oxide slurry and indium tin oxide slurry, wherein the indium tin oxide powder is a mixture of 90% indium oxide and 10% tin oxide;

[0140] S3, using screen printing technology, using a positive electrode screen printing mask to print the indium tin oxide slurry prepared in step S2 on the upper surface of the ceramic substrate obtained in step S1, and placing it on a hot platform at a temperature of 80° C. for drying to obtain an indium tin oxide thin film as the positive electrode sensitive layer thin film;

[0141] S4. Using screen printing technology, the indium oxide slurry prepared in step S2 is printed on the upper surface of the ceramic substrate obtained in step S3 using a negative electrode screen printing mask, and then placed on a hot platform at a temperature of 80° C. for drying to obtain an indium oxide thin film as the negative electrode sensitive layer thin film;

[0142] S5, annealing the ceramic substrate processed in step S4 in air at a controlled annealing temperature of 350° C. for 180 minutes to increase the carrier concentration and the density of the film microstructure, thereby obtaining a thermocouple based on the indium oxide-indium tin oxide film;

[0143] S6. Add terpineol, epoxy resin, and polyetheramine to alumina powder with a particle size of 100 nm, respectively, and stir to obtain alumina slurry;

[0144] S7, using screen printing technology, using an insulating layer screen printing mask to print the aluminum oxide slurry prepared in step S6 on the upper surface of the thermocouple obtained in step S5, and placing it on a hot platform at a temperature of 80° C. for drying, thereby preparing an aluminum oxide insulating layer film on the indium oxide-indium tin oxide film-based thermocouple;

[0145] S8, annealing the aluminum oxide insulating layer obtained in step S7 at an annealing temperature of 350° C. for 120 min in an air atmosphere to prepare an insulating layer on the upper surface of the indium oxide-indium tin oxide film-based thermocouple;

[0146] S9, adding epoxy resin, polyetheramine, glycerin, and propylene glycol to the nickel-coated copper powder respectively, and stirring to obtain a nickel-coated copper slurry;

[0147] S10, using screen printing technology, using a shielding layer screen printing mask to print the nickel-coated copper paste prepared in step S9 on the insulating layer obtained in step S8, and placing it on a hot platform at a temperature of 80° C. for drying, thereby preparing a second shielding layer on the insulating layer;

[0148] S11, using screen printing technology, using a shielding layer screen printing mask to print the nickel-coated copper paste prepared in step S9 on the lower surface of the thermocouple based on indium oxide-indium tin oxide film obtained in step S10, and placing it on a hot platform at a temperature of 80° C. for drying to prepare a first shielding layer;

[0149] S12. Annealing the indium oxide-indium tin oxide thin film thermocouple obtained in step S11 at 350° C. for 180 min in a vacuum or inert atmosphere to obtain a double-sided shielded thin film thermocouple.

[0150] Temperature perception is achieved by symmetrically preparing indium tin oxide-indium oxide sensitive films on a ceramic substrate; by rationally arranging the structural layout of each layer of the film, a thin film thermocouple with a double-sided shielding structure is obtained to reduce the introduction of external interference; by adopting appropriate heat treatment process, heat treatment time and heat treatment atmosphere, the relevant performance of each film layer is improved to achieve accurate temperature measurement in an electromagnetic environment.

[0151] Comparative Example:

[0152] A method for preparing a thin film thermocouple without a double-sided shielding structure comprises the following steps:

[0153] S1. Ultrasonic cleaning of the ceramic substrate in acetone solution for 10 min, ultrasonic cleaning in anhydrous ethanol solution for 10 min, then rinsing with deionized water, drying with nitrogen, and drying for later use;

[0154] S2. Adding terpineol, epoxy resin, and polyetheramine to indium oxide powder and indium tin oxide powder, respectively, and stirring to obtain indium oxide slurry and indium tin oxide slurry, wherein the indium tin oxide powder is a mixture of 90% indium oxide and 10% tin oxide;

[0155] S3, using screen printing technology, using a positive electrode screen printing mask to print the indium tin oxide slurry prepared in step S2 on the upper surface of the ceramic substrate obtained in step S1, and placing it on a hot platform at a temperature of 80° C. for drying to obtain an indium tin oxide thin film as the positive electrode sensitive layer thin film;

[0156] S4. Using screen printing technology, the indium oxide slurry prepared in step S2 is printed on the upper surface of the ceramic substrate obtained in step S3 using a negative electrode screen printing mask, and then placed on a hot platform at a temperature of 80° C. for drying to obtain an indium oxide thin film as the negative electrode sensitive layer thin film;

[0157] S5, the ceramic substrate treated in step S4 is annealed in air at an annealing temperature of 350 DEG C for 180 min to improve the carrier concentration and the microstructure density of the film, thereby obtaining an indium oxide-indium tin oxide film-based thermocouple;

[0158] The temperature is sensed by preparing the indium tin oxide-indium oxide sensitive film symmetrically on the ceramic substrate; however, the single film thermocouple is easy to introduce electromagnetic interference and is difficult to use in an electromagnetic field environment due to the lack of a double-sided shielding structure; however, the double-sided shielding film thermocouple can be obtained by reasonably setting the film material and the structure layout of each film layer, thereby reducing the introduction of external interference; the related performance of each film layer is improved by adopting appropriate heat treatment processes, heat treatment time and heat treatment atmosphere, so as to realize accurate temperature measurement in an electromagnetic environment.

[0159] The experimental data of the double-sided shielding electromagnetic interference resistant film thermocouple prepared by the method are as follows:

[0160]

[0161] Shielding effectiveness E1 is the electric field intensity before shielding, and E2 is the electric field intensity after shielding.

[0162] Shielding effectiveness in direct current Shielding effectiveness at 60KHz

[0163] In summary, the double-sided shielding electromagnetic interference resistant film thermocouple and the preparation method thereof realize the sensing of temperature by symmetrically setting the sensitive film on the ceramic substrate; the double-sided shielding film thermocouple is obtained by reasonably setting the structure layout of each film layer; the effective electrical isolation of the sensitive layer and the shielding layer is realized by the setting of the insulating layer; the shielding effect is effectively improved by the setting of the upper and lower shielding layers; the performance of each film layer is improved in all directions by adopting appropriate preparation processes and heat treatment processes. The double-sided shielding film thermocouple prepared can effectively reduce the interference introduced by the electromagnetic environment in the electromagnetic field environment, the shielding effectiveness is more than 40dB, has good shielding effect, and can realize accurate temperature measurement in the electromagnetic field environment.

[0164] The above content only illustrates the technical idea of the present application, and cannot limit the protection scope of the present application; any modification made according to the technical idea of the present application on the basis of the technical solution falls within the protection scope of the claims of the present application.

Claims

1. A method for preparing an anti-electromagnetic interference thin film thermocouple with a double-sided shielding structure, characterized in that: An anti-electromagnetic interference thin film thermocouple with a double-sided shielding structure comprises a ceramic substrate (3), a first shielding layer (4) is provided on the lower surface of the ceramic substrate (3), the first shielding layer (4) has the same length as the ceramic substrate (3), the insulating layer (5) has the same length as the second shielding layer (6), the thickness of the second shielding layer (6) is 20-100 μm, a positive electrode sensitive layer film (1) and a negative electrode sensitive layer film (2) are provided on the upper surface of the ceramic substrate (3), the thickness of the positive electrode sensitive layer film (1) and the negative electrode sensitive layer film (2) are both 20-100 μm, the positive electrode sensitive layer film (1) and the negative electrode sensitive layer film (2) are symmetrically arranged and contact each other, an insulating layer (5) is provided on the upper surface of the positive electrode sensitive layer film (1), the negative electrode sensitive layer film (2) and the ceramic substrate (3), the insulating layer (5) is made of Al2O3, a second shielding layer (6) is provided on the insulating layer (5), and the first shielding layer (4) and the second shielding layer (6) are grounded; One end of the positive electrode sensitive layer film (1) is connected to the left cold end (9), and one end of the negative electrode sensitive layer film (2) is connected to the right cold end (10). The left cold end (9) and the right cold end (10) are connected to a compensation wire to lead out a thermoelectric potential. The other end of the positive electrode sensitive layer film (1) and the other end of the negative electrode sensitive layer film (2) are overlapped to form a hot node temperature sensing area (7). The following steps are involved: Drying and annealing the upper surface of the ceramic substrate using indium tin oxide slurry and indium oxide slurry respectively to prepare a positive electrode sensitive layer film and a negative electrode sensitive layer film; Using nickel-coated copper slurry to dry and anneal the lower surface of the ceramic substrate to prepare a first shielding layer; An insulating layer is prepared by drying and annealing an alumina slurry on the upper surfaces of the positive electrode sensitive layer film, the negative electrode sensitive layer film, and the ceramic substrate. The drying temperature for preparing the insulating layer is 60-80° C., the annealing temperature is 150-350° C., and the annealing time is 15-120 min. The particle size of the alumina powder in the alumina slurry is 30-100 nm. A second shielding layer is prepared by drying and annealing an nickel-coated copper slurry on the upper surface of the insulating layer. The drying temperature for preparing the first shielding layer and the second shielding layer is 60-80° C. Annealing treatment is carried out in a vacuum or inert atmosphere to prepare a double-sided shielded thin film thermocouple. The drying temperature for preparing the positive electrode sensitive layer film and the negative electrode sensitive layer film is 60-80°C, the annealing temperature is 200-350°C, and the time is 15-180 minutes. Indium tin oxide powder is prepared by mixing 90% indium oxide and 10% tin oxide. The annealing temperature for preparing the double-sided shielded thin film thermocouple is 100-350°C and the time is 15-180 minutes.

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