Thin-film capacitive pressure sensor

Abstract

The invention relates to the technical field of sensors, and provides a thin-film capacitive pressure sensor, which comprises a metal shell provided with an accommodating space, the bottom of the accommodating space is provided with a support connecting part, and the support connecting part is provided with a gas channel for introducing to-be-detected gas; the core structure is arranged in the accommodating space and comprises an electrode plate, an elastic film and a connecting layer which are sequentially arranged at intervals, the connecting layer is connected with the supporting connecting part, the electrode plate, the elastic film and the connecting layer are sealed through a seal welding area to form a plate capacitor, and a first vacuum reference cavity is formed between the electrode plate and the elastic film; a process cavity is defined by the elastic film and the connecting layer and is communicated with the gas channel; the problem of thermal stress mismatch and the problem of sensor temperature drift caused by mismatch of thermal expansion coefficients are solved.

Description

Technical Field

[0001] This invention relates to the field of sensor technology, and more particularly to a thin-film capacitive pressure sensor. Background Technology

[0002] A thin-film capacitive vacuum gauge is an instrument that uses the deformation of an elastic diaphragm under pressure difference to cause a change in the capacitance of a capacitor composed of the diaphragm and fixed electrodes. By measuring the change in capacitance, the pressure difference can be characterized, and the degree of vacuum can be measured.

[0003] Currently, a typical thin-film capacitive pressure sensor in existing technology uses an elastic diaphragm to divide a vacuum gauge into two chambers. One side is connected to the system being measured, serving as the process chamber, while the other side acts as a reference chamber, which is sealed and kept under high vacuum. The elastic diaphragm and fixed electrode plates constitute a capacitor. When the pressures in the process chamber and the reference chamber are inconsistent, the pressure change causes the elastic diaphragm to deform, resulting in a change in capacitance and outputting a vacuum measurement value.

[0004] Capacitors are manufactured by creating a set of parallel-plate capacitors on a metal or ceramic dielectric, and then establishing a gas-sealed vacuum environment between the two electrodes. Traditional capacitors typically consist of a casing, electrode plates, and a flexible diaphragm. The flexible diaphragm divides the casing into two chambers. Sealing methods include laser sealing and glass sealing, requiring a vacuum reference cavity to be formed between the capacitor's flexible diaphragm and the electrode plates, and a sealed process cavity to be formed between the flexible diaphragm and external structural components. This type of capacitor manufacturing process is costly, and when the flexible diaphragm and casing are made of different materials, sealing becomes difficult and unreliable, posing a risk of process gas leakage. Summary of the Invention

[0005] This invention provides a thin-film capacitive pressure sensor to solve the problems of high sealing difficulty and low sealing reliability when the elastic film and the shell are made of different types of materials in the prior art.

[0006] This invention provides a thin-film capacitive pressure sensor, comprising: The metal casing has a receiving space, and a supporting connection part is provided at the bottom of the receiving space. The supporting connection part is provided with a gas channel for introducing the gas to be tested. The core structure, disposed in the accommodating space, includes an electrode plate, an elastic film, and a connecting layer arranged sequentially at intervals. The connecting layer is connected to the supporting connecting part. The electrode plate, the elastic film, and the connecting layer are sealed together by a sealing solder area to form an electrode plate capacitor. A first vacuum reference cavity is formed between the electrode plate and the elastic film. The elastic film and the connecting layer enclose a process cavity, which is connected to the gas channel.

[0007] The thin-film capacitive pressure sensor provided by the present invention further includes: An electrode pin, one end of which is electrically connected to the electrode plate, and the other end of which passes through the metal casing and is electrically connected to an external detection circuit; A vacuum tube, disposed on the metal casing, is used to evacuate the gas in the first vacuum reference chamber.

[0008] The thin-film capacitive pressure sensor provided by the present invention further includes: The second vacuum reference cavity is a cavity formed between the metal shell and the plate capacitor, and the second vacuum reference cavity is connected to the vacuum tube and the first vacuum reference cavity.

[0009] According to the thin-film capacitive pressure sensor provided by the present invention, the metal housing includes: The upper metal part, wherein the vacuum tube is disposed on the upper metal part; The lower metal component is provided with the support connection portion, and the support connection portion is sealed to the connection layer through the sealing weld area; A middle metal component is disposed between the upper metal component and the lower metal component, and both ends of the middle metal component are respectively connected to the upper metal component and the lower metal component.

[0010] According to the thin-film capacitive pressure sensor provided by the present invention, a thermal stress buffer structure for reducing sealing thermal stress is provided between the connection between the lower metal part and the middle metal part and the support connection part.

[0011] According to the thin-film capacitive pressure sensor provided by the present invention, the thermal stress buffer structure is disposed on the support connection portion and is a necking structure that increases the heat transfer path.

[0012] According to the thin-film capacitive pressure sensor provided by the present invention, the thermal stress buffer structure is a scale-like heat dissipation structure disposed on the lower metal part; Alternatively, the thermal stress buffer structure may be a plurality of stress relief grooves formed on the lower metal part.

[0013] According to the thin-film capacitive pressure sensor provided by the present invention, the electrode plates include: An upper surface electrode, wherein the upper surface electrode is connected to the electrode pin; The lower surface electrode is connected to the upper surface electrode through the sidewall of the electrode plate, and the lower surface electrode and the elastic film form an electrode plate capacitor.

[0014] According to the thin-film capacitive pressure sensor provided by the present invention, the distance between the connection point of the support connection part and the connection layer and the connection point between each metal part of the metal shell is between 2 and 10 cm.

[0015] According to the thin-film capacitive pressure sensor provided by the present invention, the electrode plates, the elastic film, and the connecting layer are made of the same material.

[0016] This invention provides a thin-film capacitive pressure sensor that fundamentally solves the problem of thermal stress mismatch and greatly improves sealing reliability. In traditional structures, the elastic film needs to be hermetically sealed to both a metal shell and non-metallic electrode plates. Due to the different materials, the thermal expansion requirements of the two sealing methods conflict, making the sensor prone to failure during temperature changes or sealing processes, resulting in sensor temperature drift due to mismatched thermal expansion coefficients. This invention integrates the electrode plates, elastic film, and connecting layer through a unified sealing area to form a standardized electrode capacitor, reducing the number of sealing operations for dissimilar materials and simplifying the sealing process. The difficulty lies in the fact that the sealing quality of the welding area can be centrally controlled, effectively avoiding the defects of easy leakage in the multi-area sealing of traditional structures, and ensuring the sealing performance of the first vacuum reference cavity. Furthermore, the core structure of this invention is modularly stacked, and only needs to be aligned and welded in sequence during assembly, simplifying the assembly process. The elastic film serves as a physical separation layer, enclosing the elastic film and the connecting layer to form a process cavity. The first vacuum reference cavity is formed between the electrode plate and the elastic film. The gas to be measured enters the process cavity and is completely isolated from the first vacuum reference cavity. The deformation of the elastic film is determined only by the pressure difference between the process cavity and the reference cavity, without other interfering factors, thus improving the measurement accuracy.

[0017] Furthermore, by pre-manufacturing the core structure, including the pre-sealed first vacuum reference cavity and process cavity, and then fixing it to the support connection of the metal shell through the connecting layer, the difficulty and precision requirements of the final assembly are greatly reduced. Moreover, the deformation and stress of the metal shell can be effectively isolated by the connecting layer, and the pressure of the process cavity acts directly and without interference on the elastic film, so that the stress of the shell will not be transmitted to the film and cause zero drift, ensuring the zero measurement accuracy of the sensor. This solves the problem in the prior art that the stress of the shell will directly act on the elastic film, causing the sensor output to drift and requiring frequent calibration. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1This is one of the structural schematic diagrams of a thin-film capacitive pressure sensor provided in an embodiment of the present invention.

[0020] Figure 2 This is a second schematic diagram of the structure of a thin-film capacitive pressure sensor provided in an embodiment of the present invention.

[0021] Figure 3 This is the third schematic diagram of the structure of a thin-film capacitive pressure sensor provided in the embodiments of the present invention.

[0022] Figure 4 This is the fourth schematic diagram of the structure of a thin-film capacitive pressure sensor provided in the embodiments of the present invention.

[0023] Figure 5 This is the fifth schematic diagram of the structure of a thin-film capacitive pressure sensor provided in the embodiments of the present invention.

[0024] Figure label: 1. Support connection part; 2. Gas channel; 3. Electrode plate; 4. Elastic film; 5. Connecting layer; 6. Sealing area; 7. First vacuum reference chamber; 8. Process chamber; 9. Electrode pin; 10. Vacuum tube; 11. Second vacuum reference chamber; 12. Upper metal part; 13. Middle metal part; 14. Lower metal part. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0026] In the description of the embodiments of the present invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of the present invention according to the specific circumstances.

[0027] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "method," "specific method," or "some methods," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or method is included in at least one embodiment or method of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or method. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or methods. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or methods described in this specification, as well as the features of different embodiments or methods.

[0028] The following is combined with Figures 1-5 This invention describes a thin-film capacitive pressure sensor.

[0029] This invention provides a thin-film capacitive pressure sensor, comprising: a metal shell and a core structure; the metal shell has a receiving space, and a supporting connection part 1 is provided at the bottom of the receiving space; the supporting connection part 1 has a gas channel 2 for introducing the gas to be measured; the core structure is disposed in the receiving space and includes an electrode plate 3, an elastic film 4, and a connecting layer 5 arranged sequentially at intervals; the connecting layer 5 is connected to the supporting connection part 1; the electrode plate 3, the elastic film 4, and the connecting layer 5 are sealed together by a sealing area 6 to form an electrode capacitor, and a first vacuum reference cavity 7 is formed between the electrode plate 3 and the elastic film 4; the elastic film 4 and the connecting layer 5 enclose a process cavity 8, and the process cavity 8 is connected to the gas channel 2.

[0030] As can be seen from the above solution, this invention fundamentally solves the problem of thermal stress mismatch and greatly improves sealing reliability. In traditional structures, the elastic film 4 needs to be hermetically sealed with both the metal casing and the non-metallic electrode plate 3. Due to the different materials, the thermal expansion requirements of the two sealing methods conflict, making it prone to failure during temperature changes or sealing processes, resulting in sensor temperature drift due to mismatched thermal expansion coefficients. This invention integrates the electrode plate 3, elastic film 4, and connecting layer 5 through a unified sealing area 6 to form a standardized electrode capacitor, reducing the number of sealing operations for dissimilar materials and lowering the difficulty of the sealing process. Simultaneously, the sealing... Zone 6 allows for centralized control of sealing quality, effectively avoiding the leakage defects of traditional multi-area sealing structures and ensuring the sealing performance of the first vacuum reference cavity 7. Furthermore, the core structure of this invention is modularly stacked, requiring only sequential alignment and welding during assembly, simplifying the assembly process. The elastic film 4 serves as a physical separation layer, enclosing the elastic film 4 and the connecting layer 5 to form the process cavity 8. The electrode plate 3 and the elastic film 4 form the first vacuum reference cavity 7. The gas to be measured enters the process cavity 8 and is completely isolated from the first vacuum reference cavity 7. The deformation of the elastic film 4 is determined only by the pressure difference between the process cavity 8 and the reference cavity, without other interfering factors, thus improving measurement accuracy.

[0031] Furthermore, by pre-manufacturing the core structure, including the pre-sealed first vacuum reference cavity 7 and process cavity 8, and then fixing it to the support connection part 1 of the metal shell through the connecting layer 5, the difficulty and precision requirements of the final assembly are greatly reduced. Moreover, the deformation and stress of the metal shell can be effectively isolated by the connecting layer 5, and the pressure of the process cavity 8 acts directly and without interference on the elastic film 4, so that the stress of the shell will not be transmitted to the film and cause zero drift, ensuring the zero measurement accuracy of the sensor. This solves the problem in the prior art that the stress of the shell will directly act on the elastic film 4, causing the sensor output to drift and requiring frequent calibration.

[0032] Preferably, the electrode plate 3, the elastic film 4, and the connecting layer 5 are made of the same non-metallic material, which can be ceramic.

[0033] In this configuration, in traditional core structures, the electrode plates 3 (e.g., ceramic), the elastic film 4 (e.g., metal), and the connecting layer 5 (e.g., glass) are made of different materials with significantly different coefficients of thermal expansion. When the temperature fluctuates, the deformation of each component varies, ultimately causing capacitance drift and affecting the measurement reference. By using the same non-metallic material for all three components, the reliability of the core sealing is improved, and leakage in the reference cavity is avoided. It also ensures that the components deform synchronously and uniformly when the temperature changes, without generating relative displacement or internal stress. The facing area and initial spacing of the electrode plate 3 and the elastic film 4 always meet the design values, maintaining stable measurement accuracy without the need for frequent calibration, thus ensuring the authenticity and repeatability of the measurement results.

[0034] Preferably, the material used for the sealing and welding area 6 is a metal alloy or glass.

[0035] like Figures 1-5 As shown, the connecting layer 5 has a through hole for communicating with the process chamber 8, and the through hole is connected to the gas channel 2 of the support connecting part 1, so that the gas to be tested can be introduced into the process chamber 8.

[0036] In this embodiment, the system further includes an electrode pin 9 and a vacuum tube 10. One end of the electrode pin 9 is electrically connected to the electrode plate 3, and the other end passes through the metal casing and is electrically connected to the external detection circuit. The vacuum tube 10 is disposed on the metal casing and is used to evacuate the gas in the first vacuum reference chamber 7. This configuration allows the vacuum reference chamber to be evacuated using the vacuum tube 10, achieving a vacuum state and providing a stable reference for capacitance measurement. The electrode pin 9 accurately transmits the electrical signal of capacitance change to the external detection circuit, achieving effective conversion between vacuum level and electrical signal.

[0037] Optionally, the vacuum tube 10 is made of metal, such as copper. Once the vacuum level is reached, for example, the cavity is vented until the vacuum level is less than 10. -3After Pa, the copper tube is clamped or the top of the copper tube is melted and sealed by laser welding, so that the first vacuum reference cavity 7 forms a sealed cavity and maintains a high vacuum state.

[0038] Furthermore, it also includes a second vacuum reference cavity 11, which is a cavity formed between the metal shell and the plate capacitor. The second vacuum reference cavity 11 is connected to the vacuum tube 10 and the first vacuum reference cavity 7 respectively.

[0039] With this configuration, the first vacuum reference cavity 7 between the electrode plate 3 and the elastic film 4 is an extremely narrow gap with high airflow resistance. If a vacuum is directly drawn, the pumping efficiency will be very low. The second vacuum reference cavity 11 between the metal shell and the electrode capacitor is a relatively large buffer cavity. By first pumping air into the second vacuum reference cavity 11 through the vacuum tube 10, a vacuum can be quickly established. Since the two cavities are connected, the gas in the first cavity will naturally be efficiently pumped away. Furthermore, the setting of the second vacuum reference cavity 11 will form a vacuum insulation layer between the outer surface of the core structure and the metal shell, reducing heat conduction between the electrode capacitor and the metal shell and reducing the sealing stress caused by local overheating or excessive temperature difference.

[0040] In this embodiment, the metal shell includes an upper metal part 12, a middle metal part 13, and a lower metal part 14. A vacuum tube 10 is disposed on the upper metal part 12, and a support connection part 1 is disposed on the lower metal part 14. The support connection part 1 and the connection layer 5 are sealed together by a sealing area 6 (such as metal alloy sealing or glass sealing). The middle metal part 13 is disposed between the upper metal part 12 and the lower metal part 14, and both ends of the middle metal part 13 are respectively connected to the upper metal part 12 and the lower metal part 14.

[0041] like Figures 1-5 As shown, the second vacuum reference cavity 11 is formed by the upper metal part 12, the middle metal part 13, the support connection part 1, and the outer side of the plate capacitor.

[0042] This design, through the split metal casing, allows for the first sealing and welding of the core structure to the support connection 1 of the lower metal part 14, followed by the connection of the middle metal part 13 to the upper metal part 12, achieving step-by-step assembly, reducing the risk of impact during core installation, and improving the assembly qualification rate. Furthermore, since the vacuum tube 10 needs to be fixed to the upper metal part 12 by sealing and welding, such as glass sealing or metal fusion, the sealing process will generate local high temperatures. Through the split design, the sealing and welding area 6 of the support connection 1 of the lower metal part 14 and the core connection layer 5 can be isolated from the sealing area of ​​the upper vacuum tube 10 through the middle metal part 13, significantly reducing the thermal interference of the upper vacuum tube 10 sealing on the lower sealing area and avoiding sealing failure.

[0043] Furthermore, a thermal stress buffer structure is provided between the connection between the lower metal part 14 and the middle metal part 13 and the support connection part 1 to reduce the thermal stress of the sealing process. The thermal stress buffer structure is also used to reduce the risk of sealing failure caused by heat conduction during the sealing process of the metal shell.

[0044] With this setup, when the temperature changes, due to the different thermal expansion coefficients of metals and non-metals, huge shear stress or tensile stress will be generated at their sealing points. Non-metallic materials, especially ceramics, have weak tensile and shear resistance and are very prone to cracking. By setting a thermal stress buffer structure on the heat conduction path, the stress is absorbed, ensuring the reliable connection between the support connection part 1 and the connection layer 5.

[0045] like Figures 4-5 As shown, in some embodiments, a thermal stress buffer structure is provided on the support connection 1. It is a necking structure that increases the heat transfer path. The necking structure can be integrally formed with the support connection 1.

[0046] With this configuration, when the lower metal part 14 and the middle metal part 13 are sealed together, such as by laser welding or glass welding, local high temperatures will be generated. This will cause heat to be conducted along the lower metal part 14 to the sealing area 6 of the support connection part 1 (the sealing point between the support connection part 1 and the core connection layer 5), directly affecting the sealing performance of the process cavity 8 and causing the risk of leakage of the gas to be tested. By setting a constriction structure to increase the heat transfer path, the effective heat transfer path is extended, directly reducing the heat transfer from the metal sealing area to the sealing area 6 of the support connection part 1. This ensures that the temperature of the sealing area 6 of the support connection part 1 is always maintained within a safe range, ensuring the airtightness of the process cavity 8, preventing the gas to be tested from leaking from the sealing gap, ensuring that the pressure difference between the process cavity 8 and the vacuum reference cavity truly reflects the external vacuum level to be tested, and reducing measurement errors.

[0047] In other embodiments, the thermal stress buffer structure is a scale-like heat dissipation structure disposed on the lower metal part 14.

[0048] With this configuration, the scale-like heat dissipation structure forms a multi-layered, staggered scale shape on the surface of the lower metal part 14. Compared with a smooth surface, this can significantly increase the heat dissipation surface area and the contact area with air, quickly dissipating the local high temperature generated by the sealing to the environment. This reduces the transfer of heat to the sealing area between the support connection part 1 and the core connection layer 5, avoids secondary heat failure of the sealing area 6 of the support connection part 1, ensures no leakage in the process cavity 8, and guarantees the accuracy of differential pressure measurement.

[0049] Alternatively, the thermal stress buffer structure can be a number of stress relief grooves opened on the lower metal part 14, which can cut off the stress transmission path in the stress concentration area. The shape of the stress relief grooves can be V-shaped, U-shaped, or ring-shaped. The number, depth, and position can be optimized according to specific stress simulation and experimental data, and can specifically solve thermal stress problems under different sizes and powers.

[0050] In this embodiment, the electrode plate 3 includes an upper surface electrode and a lower surface electrode. The upper surface electrode is connected to the electrode pin 9. The upper surface electrode and the lower surface electrode are connected through the side wall of the electrode plate 3. The lower surface electrode and the elastic film 4 form an electrode plate capacitor.

[0051] Furthermore, the distance between the connection point of the support connection part 1 and the connection layer 5 and the connection points between the metal parts of the metal shell is between 2 and 10 cm.

[0052] With this design, the heat-affected zone can be effectively isolated by the 2-10cm straight-line distance between the upper and middle parts, and between the middle and lower parts of the metal casing, when laser welding or brazing is performed on the various parts of the metal casing. This minimizes the impact of the high-temperature heat generated during the sealing of the various parts of the metal casing on the sealing area of ​​the capacitor core.

[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A thin-film capacitive pressure sensor, characterized in that, include: The metal casing has a receiving space, and a support connection part (1) is provided at the bottom of the receiving space. The support connection part (1) is provided with a gas channel (2) for introducing the gas to be tested. The core structure is disposed in the accommodating space and includes an electrode plate (3), an elastic film (4) and a connecting layer (5) arranged sequentially at intervals. The connecting layer (5) is connected to the supporting connecting part (1). The electrode plate (3), the elastic film (4) and the connecting layer (5) are sealed together through a sealing area (6) to form an electrode plate capacitor. A first vacuum reference cavity (7) is formed between the electrode plate (3) and the elastic film (4). The elastic film (4) and the connecting layer (5) enclose a process cavity (8), which is connected to the gas channel (2).

2. The thin-film capacitive pressure sensor according to claim 1, characterized in that, Also includes: Electrode pin (9), one end of which is electrically connected to the electrode plate (3), and the other end passes through the metal shell and is electrically connected to the external detection circuit; A vacuum tube (10) is disposed on the metal casing and is used to evacuate the gas in the first vacuum reference chamber (7).

3. The thin-film capacitive pressure sensor according to claim 2, characterized in that, Also includes: The second vacuum reference cavity (11) is a cavity formed between the metal shell and the plate capacitor. The second vacuum reference cavity (11) is connected to the vacuum tube (10) and the first vacuum reference cavity (7).

4. The thin-film capacitive pressure sensor according to claim 3, characterized in that, The metal casing includes: Upper metal part (12), the vacuum tube (10) is disposed on the upper metal part (12); The lower metal part (14) is provided with the support connection part (1), and the support connection part (1) and the connection layer (5) are sealed together through the sealing area (6); A middle metal part (13) is disposed between the upper metal part (12) and the lower metal part (14), and the two ends of the middle metal part (13) are respectively connected to the upper metal part (12) and the lower metal part (14).

5. The thin-film capacitive pressure sensor according to claim 4, characterized in that, A thermal stress buffer structure for reducing sealing thermal stress is provided between the connection between the lower metal part (14) and the middle metal part (13) and the support connection part (1).

6. The thin-film capacitive pressure sensor according to claim 5, characterized in that, The thermal stress buffer structure is disposed on the support connection part (1) and is a constriction structure that increases the heat transfer path.

7. The thin-film capacitive pressure sensor according to claim 5, characterized in that, The thermal stress buffer structure is a scale-like heat dissipation structure disposed on the lower metal part (14); Alternatively, the thermal stress buffer structure may be a plurality of stress relief grooves formed on the lower metal part (14).

8. The thin-film capacitive pressure sensor according to claim 3, characterized in that, The electrode plate (3) includes: Upper surface electrode, the upper surface electrode being connected to the electrode pin (9); The lower surface electrode is connected to the upper surface electrode through the side wall of the electrode plate (3), and the lower surface electrode and the elastic film (4) form an electrode capacitor.

9. The thin-film capacitive pressure sensor according to claim 4, characterized in that, The distance between the connection point of the support connection part (1) and the connection layer (5) and the connection point between each metal part of the metal shell is between 2 and 10 cm.

10. The thin-film capacitive pressure sensor according to any one of claims 1-9, characterized in that, The electrode plate (3), the elastic film (4), and the connecting layer (5) are made of the same material.

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