Fixed electrodes, capacitive diaphragm vacuum gauges and electronic equipment

Abstract

The embodiments of the present application disclose a fixed electrode, a capacitive thin film vacuum gauge and an electronic device, wherein the fixed electrode includes: a support plate; an electrode layer arranged on the support plate. The electrode layer includes: a cocentric compensation electrode, a first annular electrode and a second annular electrode; the first annular electrode is annular and spaced around the periphery of the compensation electrode, and the second annular electrode is annular and spaced around the periphery of the first annular electrode. The compensation electrode and the second annular electrode are connected by at least one first connecting portion, and at least one first connecting portion is insulated from the first annular electrode. In this way, by dividing the electrode layer into three parts, namely, the cocentric compensation electrode, the first annular electrode and the second annular electrode, the second annular electrode has the best linearity and the worst sensitivity, the compensation electrode has the worst linearity and the best sensitivity, and the first annular electrode has both the linearity and the sensitivity in the middle, thereby ensuring good capacitance detection capability, improving detection accuracy and temperature stability, and improving the comprehensive performance of capacitance difference response.

Description

Technical Field

[0001] The present application relates to the technical field of pressure detection, and in particular to a fixed electrode, a capacitive film vacuum gauge and an electronic device. Background Art

[0002] A vacuum gauge is an instrument for detecting the air pressure or vacuum degree in a closed environment. The measurement principle is generally to respond to certain physical changes in gas under different air pressures. At present, it is widely used in the fields of outer space aerial survey, heat treatment processing and semiconductor precision instruments. Among them, the capacitive film vacuum gauge has good repeatability, can meet the requirements of high-speed response and accurate measurement in the range of about 5 orders of magnitude from low vacuum to medium and high vacuum, and is independent of gas composition, so it has been valued in the fields of chemistry and thin film technology.

[0003] The main principle of capacitive vacuum gauge is to use the change of air pressure to cause the elastic diaphragm to deform, causing the capacitance of the capacitor composed of fixed electrodes and elastic diaphragm to change. The appropriate measurement conversion circuit converts the capacitance response signal into a voltage signal or current signal output, and the air pressure measurement can be completed through signal processing. Therefore, the quality indicators such as linearity and sensitivity on the fixed capacitor are important factors affecting the detection accuracy of the capacitive film vacuum gauge. Summary of the invention

[0004] The embodiments of the present application provide a fixed electrode, a capacitive film vacuum gauge and an electronic device to improve detection accuracy.

[0005] In a first aspect, an embodiment of the present application provides a fixed electrode, which can be used in a capacitive thin film vacuum gauge. Exemplarily, the fixed electrode includes: a support plate; an electrode layer arranged on the support plate. The electrode layer includes: a co-centric compensation electrode, a first annular electrode, and a second annular electrode; wherein the first annular electrode is annular and spaced around the periphery of the compensation electrode, and the second annular electrode is annular and spaced around the periphery of the first annular electrode. And, the compensation electrode and the second annular electrode are connected by at least one first connecting portion, and the at least one first connecting portion is insulated from the first annular electrode.

[0006] The fixed electrode in the embodiment of the present application divides the electrode layer into three parts: a co-centered compensation electrode, a first annular electrode, and a second annular electrode. Among them, the second annular electrode has the best linearity and the worst sensitivity, the compensation electrode has the worst linearity and the best sensitivity, and the first annular electrode has both linearity and sensitivity centered. By connecting the second annular electrode and the compensation electrode together, using the compensation electrode to adjust the sensitivity, and the second annular electrode to adjust the linearity, the linearity and sensitivity can be complementarily balanced. And the second annular electrode and the compensation electrode connected together can be used as a plate to form a capacitor C1 together with the elastic diaphragm. And, the linearity and sensitivity of the first annular electrode are both centered, and the first annular electrode and the elastic diaphragm together can form a capacitor C2. In this way, a highly stable capacitance difference △C (i.e., C1-C2) can be obtained to ensure good capacitance detection capability, improve detection accuracy and temperature stability, and enhance the comprehensive performance of capacitance difference response.

[0007] In the design scheme of the fixed electrode of the prior art, by setting the central circular electrode and setting the annular electrode outside the central circular electrode, the internal and external differential capacitance structure is formed. However, due to the contradictory change trend of the linearity and sensitivity of the central area and the outer area of ​​the capacitor, only by adjusting the size and position of the central circular electrode and the outer annular electrode, the requirements of the capacitance and capacitance difference response within the specified range cannot be met. Therefore, the capacitor design scheme in the prior art lacks a systematic optimization design in terms of comprehensive indicators such as linearity, sensitivity and temperature drift. The fixed electrode in the embodiment of the present application divides the electrode layer into three parts: the compensation electrode, the first annular electrode and the second annular electrode of the same center. Since the linearity of the second annular electrode is the best and the sensitivity is the worst, the linearity of the compensation electrode is the worst and the sensitivity is the best, and the linearity and sensitivity of the first annular electrode are both centered. By connecting the second annular electrode and the compensation electrode together, using the compensation electrode to adjust the sensitivity, and the second annular electrode to adjust the linearity, the linearity and sensitivity can be complementarily balanced. And the second annular electrode and the compensation electrode are connected together and can be used as a plate to form a capacitor together with the elastic diaphragm. In addition, the linearity and sensitivity of the first annular electrode are both centered, and the first annular electrode and the elastic diaphragm together can form a capacitor. In this way, a highly stable capacitance difference △C (i.e., C1-C2) can be obtained to ensure good capacitance detection capability, improve detection accuracy and temperature stability, and enhance the comprehensive performance of capacitance difference response.

[0008] Optionally, when the capacitive thin film vacuum gauge adopts the above-mentioned fixed electrode, a high-performance application scenario can be realized. For example, when the plane of the elastic diaphragm is not subjected to air pressure, it remains parallel to the plane where the electrode layer of the fixed electrode is located, and the distance between the electrode plates is adjusted so that the initial capacitance value of the variable capacitor composed of the electrode layer and the elastic diaphragm reaches the range of 10pF~100pF to ensure good capacitance detection capability.

[0009] This application does not limit the shape of the support plate. Exemplarily, the shape of the support plate can be set to a circle. And, the diameter R0 of the support plate is the diameter of the circle formed by the maximum boundary of the support plate. Optionally, when the capacitive film vacuum gauge adopts the above-mentioned fixed electrode, a high-performance application scenario can be achieved. When the capacitive film vacuum gauge realizes a high-performance application scenario, the corresponding diameter R0 ranges from 50mm to 70mm. That is, 50mm≤R0≤70mm. For example, R0=50mm, or, R0=55mm, or, R0=60mm, or, R0=65mm, or, R0=70mm. In actual applications, the specific value of R0 can be determined according to the actual application requirements, and is not limited here.

[0010] Exemplarily, the material of the support plate may be an insulating material. For example, the support plate is a ceramic substrate. The present application does not limit the material of the support plate, which may be determined according to the requirements of the actual application.

[0011] For easy installation, the support plate has a protrusion, so that the protrusion and the edge area of ​​the support plate form a step for easy installation. The shape of the protrusion can be set to be circular and co-centered with the compensation electrode, the first annular electrode and the second annular electrode. The compensation electrode, the first annular electrode and the second annular electrode are arranged on the protrusion.

[0012] In some possible implementations, the fixed electrode includes: a plurality of first connection portions. The compensation electrode includes: a plurality of compensation sub-electrodes divided along the circumferential direction; wherein the plurality of compensation sub-electrodes correspond one-to-one to the plurality of first connection portions. Moreover, each of the plurality of compensation sub-electrodes is connected to the second annular electrode through the corresponding first connection portion. In this way, the compensation electrode can be divided into a plurality of compensation sub-electrodes, and a first connection portion corresponding one-to-one to each compensation sub-electrode is provided, so that each compensation sub-electrode can be connected to the second annular electrode through the corresponding first connection portion.

[0013] In the present application, a set circle is defined, and the set circle is co-centered with the compensation electrode, the first annular electrode, and the second annular electrode, respectively. Exemplarily, the set circle can be a circle formed by the boundary of the circular support portion. Alternatively, the set circle can also be a circle formed by the boundary of the circular protrusion. Alternatively, the set circle can also be a circle of other forms, which is not limited here. The following is an example of a circle formed by the boundary of the circular support portion.

[0014] In some possible implementations, each of the first connecting portions extends along the radius of a set circle, and the set circle and the second annular electrode share a common center. Furthermore, a first angle is formed between a line connecting each of the first connecting portions and the center of the circle, and at least two of the first angles are the same.

[0015] For example, each first angle may be the same. Alternatively, some first angles may be the same and some first angles may be different. Alternatively, each first angle may be different.

[0016] In some possible implementations, in order to improve uniformity, the compensation electrode may be evenly divided into a plurality of compensation sub-electrodes along the circumferential direction. Of course, the compensation electrode may also be divided along the circumferential direction in a manner other than even division, which is not limited here.

[0017] In some possible implementations, the signal uniformity and detection accuracy can be improved by setting the connection position between the first connection portion and the compensation sub-electrode, and each of the first connection portions is connected to the midpoint of the outer arc of the corresponding compensation sub-electrode.

[0018] In some possible implementations, since the compensation sub-electrode is located inside the first annular electrode and the second annular electrode is located outside the first annular electrode, the first connecting portion can be arranged in the gap between two adjacent first sub-annular electrodes by dividing the first annular electrode into a plurality of first sub-annular electrodes. Exemplarily, the first annular electrode includes: a plurality of first sub-annular electrodes divided along the circumferential direction; the plurality of first sub-annular electrodes are connected by at least one second connecting portion, and the at least one second connecting portion is insulated from the compensation electrode and the second annular electrode; the at least one first connecting portion is arranged in the electrode layer, and each of the at least one first connecting portion is arranged in the gap between two adjacent first sub-annular electrodes.

[0019] In some possible implementations, at least one second connection portion is disposed on the electrode layer, and each of the at least one second connection portion is disposed in a gap between two adjacent compensation sub-electrodes. In order to reduce interference and process steps, all second connection portions may be disposed on the electrode layer, that is, when forming the patterns of the compensation electrode, the first annular electrode, and the second annular electrode, the pattern of the second connection portion is also formed. Since the compensation electrode is disposed inside the first annular electrode, the second connection portion may be disposed in the gap between adjacent compensation sub-electrodes.

[0020] In some possible implementations, the fixed electrode includes: a plurality of second connecting portions. The plurality of first sub-annular electrodes correspond to the plurality of second connecting portions one by one. The second connecting portions extend along the radius direction of a set circle to the center of the circle and are connected to each other, and the set circle is co-centered with the second annular electrode.

[0021] In some possible implementations, a second angle is defined between every two adjacent second connection portions, and at least two of the second angles are the same.

[0022] For example, each second angle may be the same. Alternatively, some second angles may be the same and some second angles may be different. Alternatively, each second angle may be different.

[0023] In some possible implementations, in order to improve uniformity, the first annular electrode may be evenly divided into a plurality of first sub-annular electrodes along the circumferential direction. Of course, the compensation electrode may also be divided along the circumferential direction in a manner other than even division, which is not limited here.

[0024] In some possible implementations, the signal uniformity and detection accuracy can be improved by setting the connection position between the second connection portion and the first sub-annular electrode, and each of the second connection portions is connected to the midpoint of the inner arc of the corresponding first sub-annular electrode.

[0025] In some possible implementations, the first connection portion may also be disposed on the back side of the support plate. Exemplarily, the at least one first connection portion is disposed on the side of the support plate away from the electrode layer; the support plate has at least one through-hole group; the at least one first connection portion corresponds to the at least one through-hole group one by one; each through-hole group in the at least one through-hole group includes: a first through-hole and a second through-hole; in each of the through-hole groups, the first through-hole is filled with a first conductive portion, the second through-hole is filled with a second conductive portion, the first end of the first conductive portion is connected to the compensation electrode, the first end of the second conductive portion is connected to the second annular electrode, and the second end of the first conductive portion is connected to the second end of the second conductive portion through the corresponding first connection portion.

[0026] For example, the first conductive part and the second conductive part can be respectively disposed in the first through hole and the second through hole in the form of a guide column (such as a three-dimensional copper column). Alternatively, the first conductive part and the second conductive part can be formed in the first through hole and the second through hole by filling with a conductive material.

[0027] Exemplarily, the materials of the first conductive part and the second conductive part may be conductive materials, such as metal materials (such as copper). The present application does not limit the materials of the first conductive part and the second conductive part, which may be determined according to the requirements of actual applications.

[0028] In some possible embodiments, the compensation electrode and the first annular electrode may not be divided into a plurality of sub-electrodes. Of course, the compensation electrode may also be divided into a plurality of sub-electrodes. For example, when the compensation electrode includes a plurality of compensation sub-electrodes divided along a circumferential direction, the support plate has a plurality of through-hole groups. Moreover, the plurality of compensation sub-electrodes correspond one-to-one to the plurality of through-hole groups. The compensation sub-electrode is connected to the second annular electrode through the first conductive portion, the second conductive portion, and the first connecting portion of the corresponding through-hole group. Thus, the effect of each compensation sub-electrode being connected to the second annular electrode is achieved.

[0029] In some possible implementations, the support plate is circular in shape with a diameter of R0, and the support plate is co-centered with the compensation electrode, the first annular electrode, and the second annular electrode.

[0030] Optionally, the capacitive film vacuum gauge realizes high-performance application scenarios. When the capacitive film vacuum gauge realizes high-performance application scenarios, the corresponding diameter R0 ranges from 50mm to 70mm. That is, 50mm≤R0≤70mm. For example, R0=50mm, or, R0=55mm, or, R0=60mm, or, R0=65mm, or, R0=70mm. In actual applications, the specific value of R0 can be determined according to the actual application requirements, and is not limited here.

[0031] In practical applications, the relative positions and actual areas of the first annular electrode and the second annular electrode can be adjusted to optimize linearity and sensitivity, effectively avoid excessive electrode layer area and improve processing efficiency.

[0032] In some possible implementations, the inner diameter and the outer diameter of the first annular electrode are in the range of 0.4R0 to 0.8R0, and the width of the second annular electrode in the radial direction is not greater than 0.1R0, where R0 represents the diameter of the support plate.

[0033] In some possible implementations, the contour of the orthographic projection of the compensation electrode on the support plate can be made annular, for example, the inner contour and outer contour of the orthographic projection of the compensation electrode on the support plate are both circular. In this way, a circular hollow area with a common center is set in the center area of ​​the compensation electrode. In practical applications, the relative position and actual area of ​​the compensation electrode can be adjusted to optimize linearity and sensitivity, and the electrode layer area can be effectively avoided from being too large and improve processing efficiency. Exemplarily, the outer diameter of the compensation electrode can be made less than or equal to 0.2R0.

[0034] In some possible implementations, the contour of the orthographic projection of the compensation electrode on the support plate may also be made circular, that is, the area where the center of the circle of the compensation electrode is located may also be set to be solid, and no circular hollow area is set at the center of the circle. In practical applications, the linearity and sensitivity can be optimized by adjusting the relative position and actual area of ​​the compensation electrode. Exemplarily, the diameter of the compensation electrode may be less than or equal to 0.2R0.

[0035] In some possible implementations, in actual applications, the relative positions and actual areas of the first connection portion and the second connection portion can be adjusted to effectively avoid an excessively large electrode layer area and improve processing efficiency. Exemplarily, the width of at least one of the first connection portion and the second connection portion is not greater than 0.05 R0.

[0036] In some possible implementations, the edge of the orthographic projection of at least one of the compensation electrode, the first annular electrode, and the second annular electrode on the support plate is at least one of a curve (such as a smooth curve), a sawtooth shape, and a wave shape. Of course, the shape of the edge of the orthographic projection of the compensation electrode, the first annular electrode, and the second annular electrode on the support plate can also be determined according to the needs of actual applications and is not limited here.

[0037] In a second aspect, an embodiment of the present application further provides a fixed electrode, which is also used in a capacitive film vacuum gauge. The fixed electrode includes: a support plate, and an electrode layer arranged on the support plate. The support plate is circular in shape, and the electrode layer includes: a third annular electrode. The third annular electrode is cocentric with the support plate, and the inner diameter and outer diameter of the third annular electrode are in the range of 0.2R0~0.8R0, where R0 represents the diameter of the support plate.

[0038] In some possible implementations, when the capacitive thin film vacuum gauge uses the fixed electrode in this embodiment, it can realize the application scenario of small cavity size. For example, the corresponding diameter R0 ranges from 0 <R0≤40mm。

[0039] In some possible implementations, 20 mm ≤ R0 ≤ 25 mm. For example, R0 = 20 mm, or R0 = 21 mm, or R0 = 22 mm, or R0 = 23 mm, or R0 = 24 mm, or R0 = 25 mm. In practical applications, the specific value of R0 can be determined according to actual application requirements, and is not limited here.

[0040] Exemplarily, the third annular electrode is co-centered with the support plate. Exemplarily, the third annular electrode is disposed on the protrusion and is co-centered with the protrusion.

[0041] Exemplarily, when not affected by air pressure, the plane of the elastic diaphragm remains parallel to the plane of the electrode layer of the fixed electrode, and the distance between the electrode plates is adjusted so that the initial capacitance value of the variable capacitor composed of the electrode layer and the elastic diaphragm reaches the range of 10pF~100pF to ensure good capacitance detection capability.

[0042] Optionally, when the capacitive film vacuum gauge adopts the above-mentioned fixed electrode, an application scenario with a small cavity size can be realized. Therefore, for miniaturized application scenarios, since the overall size of the capacitive film vacuum gauge is limited, a single capacitor fixed electrode solution is proposed, and the middle ring that compromises linearity and sensitivity is selected as the detection capacitor. Compared with the high-sensitivity inner circle capacitor in the prior art, the fixed capacitor provided in the embodiment of the present application can obtain higher linearity and higher temperature stability. In addition, by adjusting the inner diameter and outer diameter of the third annular electrode within the range of 0.2 to 0.8 times R0, the cavity size and the plate spacing are coordinated and matched.

[0043] In a third aspect, an embodiment of the present application further provides a capacitive thin film vacuum gauge, which includes a housing, an elastic diaphragm, a connection port, and a fixed electrode as in the first aspect or various embodiments of the first aspect or in the second aspect or various embodiments of the second aspect. The housing includes a containing cavity, the elastic diaphragm separates the containing cavity into a measuring cavity and a reference cavity, the connection port is connected to the measuring cavity, the fixed electrode is fixedly installed in the reference cavity, the fixed electrode is parallel to the elastic diaphragm, and the electrode layer is arranged facing one side of the elastic diaphragm. The fixed electrode and the elastic diaphragm form a variable capacitor.

[0044] Since the performance of the fixed electrode is good, the performance of the capacitive film vacuum gauge including the fixed electrode is also good. In addition, the principle of solving the problem of the capacitive film vacuum gauge is similar to that of the fixed electrode, so the implementation of the capacitive film vacuum gauge can refer to the implementation of the fixed electrode, and the repeated parts will not be repeated.

[0045] The capacitive thin film vacuum gauge in the embodiment of the present application can achieve different application scenarios such as high performance and miniaturization.

[0046] The capacitive film vacuum gauge in the embodiment of the present application can be applied to the field of gas pressure sensors, and can also be applied to technical fields such as pressure-sensitive smart wearable devices, gas-liquid filtration equipment, and industrial constant-pressure security monitoring equipment.

[0047] In a fourth aspect, an embodiment of the present application further provides an electronic device, including a capacitive film vacuum gauge, wherein the capacitive film vacuum gauge includes a fixed electrode as described in the aforementioned aspects and various possible implementations. The electronic device can be any electronic device that requires a capacitive film vacuum gauge, and can be used in various electronic devices in the fields of manufacturing, industry, agriculture, communications, etc., and the present application is not limited thereto. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 A schematic diagram of the structure of a capacitive thin film vacuum gauge provided in an embodiment of the present application;

[0049] Figure 2 A schematic diagram of the working principle of a capacitive thin film vacuum gauge provided in an embodiment of the present application;

[0050] Figure 3 A schematic diagram of a top view structure of a fixed electrode provided in an embodiment of the present application;

[0051] Figure 4a for Figure 3 Schematic diagram of the cross-sectional structure along the AA' direction;

[0052] Figure 4b for Figure 3 Schematic diagram of the cross-sectional structure along the BB' direction;

[0053] Figure 5 A schematic diagram of a top view structure of another fixed electrode provided in an embodiment of the present application;

[0054] Figure 6 A schematic diagram of a top view structure of another fixed electrode provided in an embodiment of the present application;

[0055] Figure 7 for Figure 6 A schematic diagram of a top view structure in which the compensation electrode and the second annular electrode are connected to each other;

[0056] Figure 8 for Figure 6 A schematic diagram of a top view structure in which the first sub-annular electrodes are connected to each other;

[0057] Fig. 9 A schematic diagram of a top view structure of another fixed electrode provided in an embodiment of the present application;

[0058] Fig.10 for Fig. 9 Schematic diagram of the cross-sectional structure along the AA' direction;

[0059] Fig.11 A schematic diagram of a top view structure of another fixed electrode provided in an embodiment of the present application;

[0060] Fig.12 for Fig.11 Schematic diagram of the cross-sectional structure along the AA' direction. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solution and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings. The specific operating method in the method embodiment can also be applied to the device embodiment or the system embodiment. It should be noted that in the description of the present application, "at least one" refers to one or more, wherein multiple refers to two or more. In view of this, "multiple" can also be understood as "at least two" in the embodiment of the present application. "And / or" describes the association relationship of the associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / ", unless otherwise specified, generally indicates that the related objects before and after are in an "or" relationship. In addition, it should be understood that in the description of the present application, words such as "first" and "second" are only used to distinguish the purpose of description, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying order.

[0062] It should be pointed out that in the embodiments of the present application, "connection" refers to electrical connection, and the connection between two electrical components can be a direct or indirect connection between the two electrical components. For example, the connection between A and B can be either a direct connection between A and B, or an indirect connection between A and B through one or more other electrical components, such as A and B can be connected, or A can be directly connected to C, C can be directly connected to B, and A and B can be connected through C. In the embodiments of the present application, "coupling" can refer to the coupling between two windings through an electromagnetic field, that is, electrical energy can be transmitted between the two windings through an electromagnetic field, which mainly includes the energy conversion process of electrical energy-magnetic field potential energy-electrical energy.

[0063] The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0064] Figure 1 A schematic structural diagram of a capacitive thin film vacuum gauge provided in an embodiment of the present application is shown.

[0065] Reference Figure 1 In some embodiments of the present application, the capacitive film vacuum gauge includes: a housing 01, an elastic diaphragm 02, a fixed electrode 03, a connection port 04 and a corresponding signal conversion circuit ( Figure 1). The housing 01 includes a housing chamber 05, and the elastic diaphragm 02 is fixedly installed in the housing chamber 05. Exemplarily, the elastic diaphragm 02 can be fixedly installed in the housing chamber 05 by welding, and the housing chamber 05 is divided into two parts, one side is a measuring chamber 051, and the other side is a reference chamber 052 (for example, the reference chamber can form a vacuum chamber), so that the measuring chamber 051 and the reference chamber 052 are two independent chambers. Of course, in practical applications, the elastic diaphragm 02 can also be installed in the housing chamber 05 by other installation methods, which are not limited here.

[0066] Continue to refer to Figure 1 The fixed electrode 03 is fixedly installed in the reference cavity 052, the fixed electrode 03 is arranged in parallel with the elastic diaphragm 02, and an electrode layer 2 is arranged on the fixed electrode 03, the electrode layer 2 is arranged facing the side of the elastic diaphragm 02, and the electrode layer 2 arranged on the fixed electrode 03 and the elastic diaphragm 02 are respectively used as two plates to form a variable capacitor. In addition, the connection port 04 is connected to the measuring cavity 051, so that the object to be measured (for example, a cavity or a pipeline) is connected through the connection port 04.

[0067] The capacitive thin film vacuum gauge in the embodiment of the present application can achieve different application scenarios such as high performance and miniaturization.

[0068] The capacitive film vacuum gauge in the embodiment of the present application can be applied to the field of gas pressure sensors, and can also be applied to technical fields such as pressure-sensitive smart wearable devices, gas-liquid filtration equipment, and industrial constant-pressure security monitoring equipment.

[0069] Figure 2 A schematic diagram showing the working principle of a capacitive thin film vacuum gauge provided in an embodiment of the present application is shown.

[0070] Reference Figure 2 When the capacitive thin film vacuum gauge is working, the elastic diaphragm 02 and the fixed electrode 03 are connected to an external power supply, which is equivalent to the two plates of a variable capacitor. The object to be detected (cavity or pipeline) is connected through the connection port 04, and the reference cavity 052 (such as a vacuum cavity) can form a vacuum state, so that a pressure difference is generated between the measuring cavity 051 and the reference cavity 052 (such as a vacuum cavity), which causes the elastic diaphragm 02 to produce elastic deformation, so that the distance between the elastic diaphragm 02 and the fixed electrode 03 changes, and the capacitance on the fixed electrode 03 also changes. The change in capacitance on the fixed electrode 03 is converted into a change in a current signal or a voltage signal through a signal conversion circuit as an output signal, and then the pressure in the measuring cavity 051 can be calculated by processing the output signal, and the air pressure measurement is completed. This method of measuring air pressure is only related to the pressure, and has nothing to do with the composition of the gas, and has a high measurement accuracy.

[0071] Figure 3A schematic diagram of the top view structure of a fixed electrode provided in an embodiment of the present application is shown. Figure 4a Shows Figure 3 Schematic diagram of the cross-sectional structure along the AA' direction. Figure 4b Shows Figure 3 Schematic diagram of the cross-sectional structure along the BB' direction. Figure 5 A schematic diagram of a top view of the structure of another fixed electrode provided in an embodiment of the present application is shown. Figure 6 A schematic diagram of a top view of the structure of another fixed electrode provided in an embodiment of the present application is shown.

[0072] Reference Figures 1 to 6 , the fixed electrode 03 includes: a support plate 1, an electrode layer 2 arranged on the support plate 1. Among them, the electrode layer 2 includes: a co-centered compensation electrode 21, a first annular electrode 22 and a second annular electrode 23. Among them, the first annular electrode 22 is annular and spaced outside the compensation electrode 21, and the second annular electrode 23 is annular and spaced outside the first annular electrode 22. There is a gap between the compensation electrode 21 and the first annular electrode 22, and there is a gap between the first annular electrode 22 and the second annular electrode 23 to achieve an insulation effect. Exemplarily, an insulating material (such as a ceramic material) can be filled in the gap between the compensation electrode 21 and the first annular electrode 22, and the gap between the first annular electrode 22 and the second annular electrode 23 to further improve the insulation effect. Of course, other materials may not be filled, and this is not limited here.

[0073] Furthermore, by providing a first connection portion insulated from the first annular electrode 22 , the compensation electrode 21 and the second annular electrode 23 can be connected via at least one first connection portion, thereby achieving electrical connection between the compensation electrode 21 and the second annular electrode 23 .

[0074] According to the mechanical response characteristics of the elastic deformation mechanism of the elastic diaphragm under the action of air pressure, it can be deduced from theory that the capacitance value of the electrode layer of the fixed electrode corresponds to the spacing change of the elastic diaphragm area linearly, but because the capacitance difference is proportional to the inverse of the distance between the plates, the capacitance difference is nonlinear with the change of air pressure. According to the above technical principles, the deformation degree of the center position area of ​​the elastic diaphragm is high, so the electrode layer of the fixed electrode in the corresponding area has high sensitivity and poor linearity, while the deformation degree of the edge area of ​​the elastic diaphragm is low, and the electrode layer of the fixed electrode in the corresponding area has low sensitivity and high linearity. Based on this, in the embodiment of the present application, the electrode layer is divided into three parts: the compensation electrode with the same center, the first annular electrode and the second annular electrode, among which the second annular electrode has the best linearity and the worst sensitivity, the compensation electrode has the worst linearity and the best sensitivity, and the linearity and sensitivity of the first annular electrode 22 are both centered. By connecting the second annular electrode and the compensation electrode together, using the compensation electrode to adjust the sensitivity and the second annular electrode to adjust the linearity, the linearity and sensitivity can be complementarily balanced. The second annular electrode and the compensation electrode are connected together to form a plate and a capacitor C1 together with the elastic diaphragm. In addition, the linearity and sensitivity of the first annular electrode are both centered, and the first annular electrode and the elastic diaphragm together form a capacitor C2. In this way, a highly stable capacitance difference △C (i.e. C1-C2) can be obtained to ensure good capacitance detection capability, improve detection accuracy and temperature stability, and enhance the comprehensive performance of capacitance difference response.

[0075] In the design scheme of the fixed electrode of the prior art, by setting the central circular electrode and setting the annular electrode outside the central circular electrode, the internal and external differential capacitance structure is formed. However, due to the contradictory change trend of the linearity and sensitivity of the central area and the outer area of ​​the capacitor, only by adjusting the size and position of the central circular electrode and the outer annular electrode, the requirements of the capacitance and capacitance difference response within the specified range cannot be met. Therefore, the capacitor design scheme in the prior art lacks a systematic optimization design in terms of comprehensive indicators such as linearity, sensitivity and temperature drift. The fixed electrode in the embodiment of the present application divides the electrode layer into three parts: the compensation electrode, the first annular electrode and the second annular electrode of the same center. Since the linearity of the second annular electrode is the best and the sensitivity is the worst, the linearity of the compensation electrode is the worst and the sensitivity is the best, and the linearity and sensitivity of the first annular electrode are both centered. By connecting the second annular electrode and the compensation electrode together, using the compensation electrode to adjust the sensitivity, and the second annular electrode to adjust the linearity, the linearity and sensitivity can be complementarily balanced. And the second annular electrode and the compensation electrode are connected together and can be used as a plate to form a capacitor together with the elastic diaphragm. In addition, the linearity and sensitivity of the first annular electrode are both centered, and the first annular electrode and the elastic diaphragm together can form a capacitor. In this way, a highly stable capacitance difference △C (i.e., C1-C2) can be obtained to ensure good capacitance detection capability, improve detection accuracy and temperature stability, and enhance the comprehensive performance of capacitance difference response.

[0076] Optionally, when the capacitive thin film vacuum gauge adopts the above-mentioned fixed electrode, a high-performance application scenario can be realized. For example, when the plane of the elastic diaphragm is not subjected to air pressure, it remains parallel to the plane where the electrode layer of the fixed electrode is located, and the distance between the electrode plates is adjusted so that the initial capacitance value of the variable capacitor composed of the electrode layer and the elastic diaphragm reaches the range of 10pF~100pF to ensure good capacitance detection capability.

[0077] The present application does not limit the shape of the support plate. Figure 3 , Figure 5 as well as Figure 6 , the shape of the support plate 1 can be set to a circle. And, the diameter R0 of the support plate is the diameter of the circle formed by the maximum boundary of the support plate 1. Optionally, when the capacitive film vacuum gauge adopts the above-mentioned fixed electrode, a high-performance application scenario can be achieved. When the capacitive film vacuum gauge realizes a high-performance application scenario, the corresponding diameter R0 ranges from 50mm to 70mm. That is, 50mm≤R0≤70mm. For example, R0=50mm, or, R0=55mm, or, R0=60mm, or, R0=65mm, or, R0=70mm. In actual applications, the specific value of R0 can be determined according to the actual application requirements, and is not limited here.

[0078] Exemplarily, the material of the support plate may be an insulating material. For example, the support plate is a ceramic substrate. The present application does not limit the material of the support plate, which may be determined according to the requirements of the actual application.

[0079] For ease of installation, illustratively, refer to Figures 3 to 6 The support plate 1 has a protrusion 11, so that the protrusion 11 and the edge area of ​​the support plate 1 form a step for easy installation. The shape of the protrusion 11 can be set to be circular and co-centered with the compensation electrode 21, the first annular electrode 22 and the second annular electrode 23. The compensation electrode 21, the first annular electrode 22 and the second annular electrode 23 are arranged on the protrusion 11.

[0080] Exemplarily, the compensation electrode 21 may be divided into a plurality of compensation sub-electrodes, and a first connection portion corresponding to each compensation sub-electrode is provided, so that each compensation sub-electrode can be connected to the second annular electrode through the corresponding first connection portion. Optionally, the compensation electrode may be divided into a plurality of compensation sub-electrodes along the circumferential direction. For example, in order to improve uniformity, the compensation electrode may be evenly divided into a plurality of compensation sub-electrodes along the circumferential direction. Of course, the compensation electrode may also be divided along the circumferential direction in a manner other than evenly divided, which is not limited here.

[0081] In some examples, reference Figure 3 and Figure 5 , the compensation electrode 21 may include: two compensation sub-electrodes evenly divided along the circumferential direction, namely, the compensation sub-electrodes 211-1 and 211-2, that is, the compensation electrode 21 is divided into two parts. In addition, the fixed electrode 03 may include two first connection parts, namely, the first connection parts 3-1 and 3-2, and the first connection parts 3-1 and 3-2 are insulated from the first annular electrode 22. Among them, the first connection part 3-1 corresponds to the compensation sub-electrode 211-1, and the compensation sub-electrode 211-1 is connected to the second annular electrode 23 through the first connection part 3-1, so that the compensation sub-electrode 211-1 and the second annular electrode 23 are electrically connected. And, the first connection part 3-2 corresponds to the compensation sub-electrode 211-2, and the compensation sub-electrode 211-2 is connected to the second annular electrode 23 through the first connection part 3-2, so that the compensation sub-electrode 211-2 and the second annular electrode 23 are electrically connected.

[0082] In some other examples, reference Figure 6 , the compensation electrode 21 may include: three compensation sub-electrodes evenly divided along the circumferential direction, namely, compensation sub-electrodes 211-1, 211-2, and 211-3, that is, the compensation electrode 21 is divided into three parts. In addition, the fixed electrode 03 may include three first connection parts, namely, first connection parts 3-1, 3-2, and 3-3, and the first connection parts 3-1, 3-2, and 3-3 are all insulated from the first annular electrode 22. Among them, the first connection part 3-1 corresponds to the compensation sub-electrode 211-1, and the compensation sub-electrode 211-1 is connected to the second annular electrode 23 through the first connection part 3-1, so that the compensation sub-electrode 211-1 is electrically connected to the second annular electrode 23. In addition, the first connection part 3-2 corresponds to the compensation sub-electrode 211-2, and the compensation sub-electrode 211-2 is connected to the second annular electrode 23 through the first connection part 3-2, so that the compensation sub-electrode 211-2 is electrically connected to the second annular electrode 23. Furthermore, the first connection portion 3 - 3 corresponds to the compensation sub-electrode 211 - 3 , and the compensation sub-electrode 211 - 3 is connected to the second annular electrode 23 via the first connection portion 3 - 3 , thereby achieving electrical connection between the compensation sub-electrode 211 - 3 and the second annular electrode 23 .

[0083] In order to reduce interference and process steps, all first connection parts may be arranged on the electrode layer, that is, when forming the patterns of the compensation electrode, the first annular electrode and the second annular electrode, the first connection part pattern is also formed.

[0084] Since the compensation sub-electrode is located inside the first annular electrode and the second annular electrode is located outside the first annular electrode, the first connecting portion can be arranged in the gap between two adjacent first sub-annular electrodes by dividing the first annular electrode into a plurality of first sub-annular electrodes. Since the first annular electrode is divided into a plurality of first sub-annular electrodes, a plurality of second connecting portions corresponding to the plurality of first sub-annular electrodes can be arranged so that each first sub-annular electrode can be connected to each other through the corresponding second connecting portion. Optionally, the first annular electrode can be divided into a plurality of first sub-annular electrodes along the circumferential direction. For example, in order to improve uniformity, the first annular electrode can be evenly divided into a plurality of first sub-annular electrodes along the circumferential direction. Of course, the first annular electrode can also be divided along the circumferential direction in a manner other than even division, which is not limited here.

[0085] In order to reduce interference and process steps, all second connection parts can be arranged on the electrode layer 2, that is, when forming the patterns of the compensation electrode 21, the first annular electrode 22 and the second annular electrode 23, the pattern of the second connection part is also formed. Since the compensation electrode 21 is arranged inside the first annular electrode 22, the second connection part can be arranged in the gap between adjacent compensation sub-electrodes.

[0086] In some examples, reference Figure 3 and Figure 5 , the first annular electrode 22 may include: two first sub-annular electrodes evenly divided along the circumferential direction, namely, first sub-annular electrodes 221-1 and 221-2, that is, the first annular electrode 22 is divided into two parts. There are two gaps between the first sub-annular electrodes 221-1 and 221-2, the first connecting portion 3-1 is arranged in one of the two gaps, and the first connecting portion 3-2 is arranged in the other of the two gaps to achieve insulation. And, in order to electrically connect the first sub-annular electrodes 221-1 and 221-2, second connecting portions 4-1 and 4-2 may be arranged in the fixed electrode 03. And, the first sub-annular electrode 221-1 corresponds to the second connecting portion 4-1, and the first sub-annular electrode 221-2 corresponds to the second connecting portion 4-2, so that the first sub-annular electrodes 221-1 and 221-2 are connected through the second connecting portions 4-1 and 4-2. Furthermore, to prevent the first annular electrode 22 from being connected to the compensation electrode 21, the second connection parts 4-1 and 4-2 can be insulated from the compensation electrode 21. For example, the second connection parts 4-1 and 4-2 are arranged in the gap between two adjacent compensation sub-electrodes 211-1 and 211-2 to achieve insulation.

[0087] In other examples, refer to Figure 6, the first annular electrode 22 may include: three first sub-annular electrodes evenly divided along the circumferential direction, namely, first sub-annular electrodes 221-1, 221-2, and 221-3, that is, the first annular electrode 22 is divided into three parts. The first connecting portion 3-1 is arranged in the gap between the first sub-annular electrodes 221-3 and 221-1, the first connecting portion 3-2 is arranged in the gap between the first sub-annular electrodes 221-1 and 221-2, and the first connecting portion 3-3 is arranged in the gap between the first sub-annular electrodes 221-2 and 221-3 to achieve insulation. In addition, in order to electrically connect the first sub-annular electrodes 221-1, 221-2, and 221-3, second connecting portions 4-1, 4-2, and 4-3 may be arranged in the fixed electrode 03. Furthermore, the first sub-annular electrode 221-1 corresponds to the second connection portion 4-1, the first sub-annular electrode 221-2 corresponds to the second connection portion 4-2, and the first sub-annular electrode 221-3 corresponds to the second connection portion 4-3, so that the first sub-annular electrodes 221-1, 221-2, and 221-3 are connected to each other through the second connection portions 4-1, 4-2, and 4-3. Furthermore, in order to prevent the first annular electrode 22 from being connected to the compensation electrode 21, the second connection portions 4-1, 4-2, and 4-3 can be insulated from the compensation electrode 21. For example, the second connection portion 4-1 is set in the gap between the compensation sub-electrodes 211-1 and 211-2, the second connection portion 4-2 is set in the gap between the compensation sub-electrodes 211-2 and 211-3, and the second connection portion 4-3 is set in the gap between the compensation sub-electrodes 211-3 and 211-1 to achieve insulation.

[0088] In the present application, a set circle is defined, and the set circle is co-centered with the compensation electrode, the first annular electrode, and the second annular electrode, respectively. Exemplarily, the set circle can be a circle formed by the boundary of the circular support portion. Alternatively, the set circle can also be a circle formed by the boundary of the circular protrusion. Alternatively, the set circle can also be a circle of other forms, which is not limited here. The following is an example of a circle formed by the boundary of the circular support portion.

[0089] In the present application, by defining a set circle, the first connecting portion and the second connecting portion can extend along the radius direction of the set circle. Figure 3 and Figure 5 , the first connecting parts 3-1 and 3-2 extend along the radial direction of the circular support part, thereby electrically connecting the compensation sub-electrodes 211-1 and 211-2 to the second annular electrode 23. And the second connecting parts 4-1 and 4-2 extend along the radial direction of the circular support part to the center thereof and connect to each other, thereby electrically connecting the first sub-annular electrodes 221-1 and 221-2 to each other. For example, referring to Figure 6The first connecting parts 3-1, 3-2, and 3-3 extend along the radial direction of the circular support part, thereby electrically connecting the compensation sub-electrodes 211-1, 211-2, and 211-3 to the second annular electrode 23. And the second connecting parts 4-1, 4-2, and 4-3 extend along the radial direction of the circular support part to the center thereof and connect to each other, thereby electrically connecting the first sub-annular electrodes 221-1, 221-2, and 221-3 to each other.

[0090] In some embodiments of the present application, a first angle is formed between each first connecting portion and the line connecting the center of the circle, and at least two first angles are the same. Figure 5 When there are two first connection parts, the lines connecting the two first connection parts 3-1 and 3-2 and the center of the circle can extend along the same straight line, and the first angle β1 between the line connecting the first connection part 3-1 and the center of the circle and the line connecting the first connection part 3-2 and the center of the circle can be 180°.

[0091] For example, Figure 7 Shows Figure 6 A schematic diagram of a top view of a structure in which the compensation electrode and the second annular electrode are connected to each other. Figure 6 and Figure 7 As shown, when there are three first connecting parts, there is a first angle β1-1 between the line connecting the first connecting part 3-1 and the center of the circle and the line connecting the first connecting part 3-2 and the center of the circle, there is a first angle β1-2 between the line connecting the first connecting part 3-2 and the center of the circle and the line connecting the first connecting part 3-3 and the center of the circle, and there is a first angle β1-3 between the line connecting the first connecting part 3-3 and the center of the circle and the line connecting the first connecting part 3-1 and the center of the circle. Exemplarily, the first angles β1-1, β1-2, and β1-3 can be made the same, and the first angles β1-1, β1-2, and β1-3 are 120° respectively. In this way, by setting each first angle to be the same, the first connecting parts can be distributed on the support plate 1 in a uniformly divergent manner.

[0092] In some embodiments of the present application, some of the first angles may be the same, and some of the first angles may be different. Figure 7 , the first angles β1-1 and β1-2 may be the same, while the first angles β1-1 and β1-3 may be different. Alternatively, the first angles β1-1 and β1-3 may be the same, while the first angles β1-1 and β1-2 may be different. Alternatively, the first angles β1-2 and β1-3 may be the same, while the first angles β1-1 and β1-2 may be different.

[0093] In some embodiments of the present application, each first angle may be different. For example, referring to Figure 7 , any two of the first angles β1-1, β1-2, and β1-3 can also be made different.

[0094] In some embodiments of the present application, there is a second angle between every two adjacent second connecting portions, and at least two second angles are the same. Figure 5 When there are two second connection parts, the two second connection parts 4-1 and 4-2 can extend along a straight line after being connected to each other, and the second angle β2 between the line connecting the second connection part 4-1 and the center of the circle and the line connecting the second connection part 4-2 and the center of the circle can be 180°.

[0095] For example, Figure 8 Shows Figure 6 A schematic diagram of a top view of the structure in which the first sub-annular electrodes are connected to each other. Figure 6 and Figure 8 , when there are three second connecting parts, there is a second angle β2-1 between the second connecting part 4-1 and the second connecting part 4-2, there is a second angle β2-2 between the second connecting part 4-2 and the second connecting part 4-3, and there is a second angle β2-3 between the second connecting part 4-3 and the second connecting part 4-1. Exemplarily, the second angles β2-1, β2-2, and β2-3 can be made the same, and the second angles β2-1, β2-2, and β2-3 are 120° respectively. In this way, by setting each second angle to be the same, the second connecting parts can be distributed on the support plate 1 in a uniformly divergent manner.

[0096] In some embodiments of the present application, some of the second angles may be the same, and some of the second angles may be different. Figure 8 , the second angles β2-1 and β2-2 may be the same, while the second angles β2-1 and β2-3 may be different. Alternatively, the second angles β2-1 and β2-3 may be the same, while the second angles β2-1 and β2-2 may be different. Alternatively, the second angles β2-2 and β2-3 may be the same, while the second angles β2-1 and β2-2 may be different.

[0097] In some embodiments of the present application, each second angle may be different. For example, referring to Figure 7 , any two of the second angles β2-1, β2-2, and β2-3 can also be made different.

[0098] In some examples of the present application, the contour of the orthographic projection of the compensation electrode 21 on the support plate 1 can be made to be annular, for example, the inner contour and the outer contour of the orthographic projection of the compensation electrode on the support plate are both circular. In this way, a circular hollow area with the same center as the set circle is set in the center area of ​​the compensation electrode. For example, referring to Figure 3 The contour of the positive projection of the compensation electrode 21 on the support plate 1 is a ring, which means that the two compensation sub-electrodes 211-1 and 211-2 are two arches respectively.

[0099] In practical applications, the relative position and actual area of ​​the compensation electrode can be adjusted to optimize linearity and sensitivity, effectively avoid excessive electrode layer area and improve processing efficiency. Figure 3 , the outer diameter R21 of the compensation electrode 21 can be less than or equal to 0.2R0. Furthermore, 0.05R0≤R21≤0.2R0, so that in practical applications, R21 can be selected from a suitable value between 0.05R0 and 0.2R0, and this application does not limit this.

[0100] In other examples of the present application, the contour of the orthographic projection of the compensation electrode 21 on the support plate 1 may also be a circle, that is, the area where the center of the circle of the compensation electrode 21 is located may also be set to be solid, and no circular hollow area is set at the center of the circle. Figure 5 , the area where the center of the compensation electrode 21 is located can be solid, which means that the two compensation sub-electrodes 211-1 and 211-2 are in the form of two semicircles. Figure 6 The area where the center of the compensation electrode 21 is located can be solid, which means that the three compensation sub-electrodes 211-1, 211-2, and 211-3 are in the form of three sectors. In some examples, since the compensation electrode 21 is divided into multiple supplementary sub-electrodes, the center angle of each compensation sub-electrode is the same.

[0101] In practical applications, the linearity and sensitivity can be optimized by adjusting the relative position and actual area of ​​the compensation electrode 21. Figure 5 and Figure 6 , the diameter R21' of the compensation electrode 21 can be less than or equal to 0.2R0. Further, 0.05R0≤R21'≤0.2R0, so in practical applications, R21' can be selected from a suitable value in the range of 0.05R0~0.2R0, which is not limited in the present application.

[0102] In the present application, the compensation electrode 21 can adopt a circular design or an annular design to adapt to different electrode spacing schemes, thereby obtaining a stable linearity change trend, sensitivity change trend and temperature drift stability.

[0103] In some embodiments of the present application, the connection position between the first connection portion and the compensation sub-electrode can be set to improve signal uniformity and detection accuracy. Figure 3 and Figure 5 The first connection portion 3-1 is connected to the midpoint of the outer arc of the compensation sub-electrode 211-1, and the first connection portion 3-2 is connected to the midpoint of the outer arc of the compensation sub-electrode 211-2. Figure 6The first connection portion 3-1 is connected to the midpoint of the outer arc of the compensation sub-electrode 211-1, the first connection portion 3-2 is connected to the midpoint of the outer arc of the compensation sub-electrode 211-2, and the first connection portion 3-3 is connected to the midpoint of the outer arc of the compensation sub-electrode 211-3.

[0104] Exemplarily, the inner and outer sides of the orthographic projection of the first annular electrode 22 on the support plate 1 are both circular, and the inner and outer sides of the orthographic projection of the second annular electrode 23 on the support plate 1 are also circular. The signal uniformity and detection accuracy can be improved by setting the connection position between the second connecting portion and the first sub-annular electrode. Exemplarily, referring to Figure 3 and Figure 5 The second connection portion 4-1 is connected to the midpoint of the inner arc of the first sub-annular electrode 221-1, and the second connection portion 4-2 is connected to the midpoint of the inner arc of the first sub-annular electrode 221-2. Figure 6 The second connecting portion 4-1 is connected to the midpoint of the inner arc of the first sub-annular electrode 221-1, the second connecting portion 4-2 is connected to the midpoint of the inner arc of the first sub-annular electrode 221-2, and the second connecting portion 4-3 is connected to the midpoint of the inner arc of the first sub-annular electrode 221-3.

[0105] In practical applications, the relative positions and actual areas of the first annular electrode 22 and the second annular electrode 23 can be adjusted to optimize linearity and sensitivity, and to effectively avoid the electrode layer 2 from being too large and improve processing efficiency. Figure 3 , the inner diameter R22n of the first annular electrode 22 can be in the range of 0.4R0~0.8R0, so in practical applications, R22n can be selected from 0.4R0~0.8R0. Further, R22n can be in the range of 0.4R0~0.6R0, so in practical applications, R22n can be selected from 0.4R0~0.6R0, and this application does not limit this.

[0106] For example, refer to Figure 3 , the outer diameter R22w of the first annular electrode 22 can be in the range of 0.4R0~0.8R0, so in practical applications, R22w can be selected from 0.4R0~0.8R0. Further, the range of R22w can be 0.4R0~0.6R0, so in practical applications, R22w can be selected from 0.4R0~0.6R0, and this application does not limit this.

[0107] For example, refer to Figure 3, the outer diameter R23w of the second annular electrode 23 can be in the range of 0.4R0~0.8R0, so in practical applications, R23w can be selected from 0.4R0~0.8R0. Further, the range of R23w can be 0.6R0~0.8R0, so in practical applications, R23w can be selected from 0.6R0~0.8R0, and this application does not limit this.

[0108] For example, refer to Figure 3 , the width W23 of the second annular electrode 23 in the radial direction can be less than or equal to 0.1R0, and W23 can be greater than 0. In practical applications, W23 can be selected from a suitable value greater than 0 and less than or equal to 0.1R0, and this application does not limit this. Further, W23 can be in the range of 0.01R0~0.05R0, so in practical applications, W23 can be selected from a suitable value from 0.01R0~0.05R0, and this application does not limit this.

[0109] In practical applications, the relative positions and actual areas of the compensation electrode 21, the first annular electrode 22 and the second annular electrode 23 can be adjusted to optimize the comprehensive performance of the linearity change trend, sensitivity change trend and temperature drift stability of the capacitors C1 and C2.

[0110] In practical applications, the relative position and actual area of ​​the first connecting portion can be adjusted to effectively avoid an excessively large area of ​​the electrode layer and improve processing efficiency. Figure 5 , the width W3 of the first connection portion (such as 3-1, 3-2) can be no greater than 0.05R0, and W3 can be greater than 0. In this way, in practical applications, W3 can be selected from a suitable value greater than 0 and less than or equal to 0.05R0, and this application does not limit this.

[0111] Optionally, the width W3 of each first connection portion may be made the same, so that each first connection portion may be evenly arranged, further optimizing linearity and sensitivity.

[0112] In practical applications, the relative position and actual area of ​​the second connecting portion can be adjusted to effectively avoid the electrode layer 2 from being too large and improve processing efficiency. Figure 5 , the width W4 of the second connection portion (such as 4-1, 4-2) can be no greater than 0.05R0, and W4 can be greater than 0. In practical applications, W4 can be selected from a suitable value greater than 0 and less than or equal to 0.05R0, and this application does not limit this.

[0113] Optionally, the width W4 of each second connection portion may be made the same, so that each second connection portion may be evenly arranged, further optimizing linearity and sensitivity.

[0114] For example, a process of forming a pattern using a photoresist, a mask, an exposure machine, etc. in a process of film formation, exposure, development, etc. can be used to form a pattern on the support plate. Alternatively, a process of forming a pattern using a 3D printing process, a transfer process, etc. can be used to form a pattern on the support plate.

[0115] Exemplarily, the material of the electrode layer may be a conductive material, such as a metal material. The present application does not limit the material of the electrode layer, which may be determined according to the requirements of the actual application.

[0116] The present application does not limit the thickness of the electrode layer (ie, the thickness in a direction perpendicular to the plane where the support plate is located). Exemplarily, the thickness of the electrode layer may be several micrometers.

[0117] Through simulation verification of the fixed electrode in the embodiment of the present application, it is found that the structure of the fixed electrode provided in the embodiment of the present application has better comprehensive nonlinearity / sensitivity performance, more stable temperature drift, and smaller deviation at full scale than the fixed electrode solution in the prior art.

[0118] In some embodiments of the present application, the edge of the orthographic projection of at least one of the compensation electrode, the first annular electrode, and the second annular electrode on the support plate is at least one of a curve (such as a smooth curve), a sawtooth shape, and a wave shape. Of course, the shape of the edge of the orthographic projection of the compensation electrode, the first annular electrode, and the second annular electrode on the support plate can also be determined according to the needs of actual applications and is not limited here.

[0119] Fig. 9 A schematic diagram of a top view of the structure of another fixed electrode provided in an embodiment of the present application is shown. Fig.10 Shows Fig. 9 Schematic diagram of the cross-sectional structure along the AA' direction.

[0120] Reference Fig. 9 and Fig.10 In some other embodiments provided in the present application, the fixed electrode includes: a support plate 1, a compensation electrode 21, a first annular electrode 22, and a second annular electrode 23. This embodiment is a modification of the implementation method in the above embodiment. The following only describes the differences between this embodiment and the above embodiment, and the similarities are not repeated here.

[0121] In the examples provided in this application, refer to Fig. 9 and Fig.10Alternatively, the first connection portion 3 may be arranged on the back of the support plate, that is, the first connection portion 3 is arranged on the side of the support plate 1 away from the electrode layer 2, so as to connect the compensation electrode and the second annular electrode through the first connection portion 3. Optionally, the first connection portion 3 may be arranged as one or more, Fig. 9 Take the example of setting one first connection part 3 .

[0122] In order to achieve connection, the support plate has one or more through hole groups, and each first connection portion is arranged in a one-to-one correspondence with each through hole group. Fig. 9 Take the case where one first connection portion 3 is provided and one through hole group is provided as an example. Fig. 9 and Fig.10 , the first connection part 3 is arranged corresponding to the through hole group 5, and the through hole group 5 includes: a first through hole 51 and a second through hole 52. The first through hole 51 and the second through hole 52 respectively penetrate the support plate. The first through hole 51 is filled with a first conductive part 61, and the second through hole 52 is filled with a second conductive part 62. The first end of the first conductive part 61 is connected to the compensation electrode 21, the first end of the second conductive part 62 is connected to the second annular electrode 23, and the second end of the first conductive part 61 is connected to the second end of the second conductive part 62 through the first connection part 3, so that the compensation electrode 21 and the second annular electrode 23 are connected to each other.

[0123] Exemplarily, the first conductive part 61 and the second conductive part 62 may be provided in the first through hole 51 and the second through hole 52 in the form of guide pillars (such as three-dimensional copper pillars), respectively. Alternatively, the first conductive part 61 and the second conductive part 62 may be formed in the first through hole 51 and the second through hole 52 by filling with conductive materials.

[0124] Exemplarily, the materials of the first conductive part 61 and the second conductive part 62 may be conductive materials, such as metal materials (such as copper). The present application does not limit the materials of the first conductive part and the second conductive part, which may be determined according to the requirements of the actual application.

[0125] For example, refer to Fig. 9 , the compensation electrode and the first annular electrode may not be divided into a plurality of sub-electrodes. Of course, the compensation electrode may also be divided into a plurality of sub-electrodes. For example, when the compensation electrode includes a plurality of compensation sub-electrodes divided along a circumferential direction, the support plate has a plurality of through-hole groups. Moreover, the plurality of compensation sub-electrodes correspond one-to-one to the plurality of through-hole groups. The compensation sub-electrode is connected to the second annular electrode through the first conductive portion, the second conductive portion, and the first connecting portion of the corresponding through-hole group. Thus, the effect of each compensation sub-electrode being connected to the second annular electrode is achieved.

[0126] Fig.11 A schematic diagram of a top view of the structure of another fixed electrode provided in an embodiment of the present application is shown. Fig.12 Shows Fig.11 Schematic cross-sectional structure diagram along the AA' direction.

[0127] Referring to Fig.11 and Fig.12 , in some other embodiments provided by the present application, the fixed electrode includes: a support plate 1, and an electrode layer 2 disposed on the support plate 1. The electrode layer 2 includes a third annular electrode 24. This embodiment is a deformation of the implementation manner in the above embodiment. Only the differences between this embodiment and the above embodiment will be described below, and the same parts will not be elaborated here.

[0128] In the embodiment of the present application, referring to Fig.11 and Fig.12 , the shape of the support plate 1 is circular, and its diameter is R0. Optionally, when the capacitive thin-film vacuum gauge adopts the fixed electrode in this embodiment, an application scenario with a small cavity size can be realized. Exemplarily, the corresponding range of the diameter R0 is 0 < R0 ≤ 40 mm. Further, 20 mm ≤ R0 ≤ 25 mm can be set. For example, R0 = 20 mm, or R0 = 21 mm, or R0 = 22 mm, or R0 = 23 mm, or R0 = 24 mm, or R0 = 25 mm. In actual applications, the specific value of R0 can be determined according to actual application requirements, and is not limited herein.

[0129] In the embodiment of the present application, referring to Fig.11 and Fig.12 , the third annular electrode 24 is concentric with the support plate 1. Exemplarily, the third annular electrode 24 is disposed on the protruding portion 11 and is concentric with the protruding portion 11.

[0130] Exemplarily, referring to Fig.11 , the inner diameter R24n of the third annular electrode 24 ranges from 0.2R0 to 0.8R0. In this way, in actual applications, a suitable value of R24n can be selected from 0.2R0 to 0.8R0, and the present application does not limit this.

[0131] Exemplarily, referring to Fig.11 , the outer diameter R24w of the third annular electrode 24 ranges from 0.2R0 to 0.8R0. In this way, in actual applications, a suitable value of R24w can be selected from 0.2R0 to 0.8R0, and the present application does not limit this.

[0132] Exemplarily, when the elastic diaphragm is not under the action of air pressure, the plane of the elastic diaphragm is parallel to the plane where the electrode layer of the fixed electrode is located. By adjusting the plate spacing, the initial capacitance value of the variable capacitor formed by the electrode layer and the elastic diaphragm reaches the range of 10 pF to 100 pF to ensure good capacitance detection ability.

[0133] An embodiment of the present application also provides a capacitive diaphragm vacuum gauge including a fixed electrode as described in any of the aforementioned embodiments.

[0134] An embodiment of the present application further provides an electronic device, comprising the aforementioned capacitive film vacuum gauge, wherein the capacitive film vacuum gauge comprises a fixed electrode as described in any of the aforementioned embodiments.

[0135] Optionally, when the capacitive film vacuum gauge adopts the above-mentioned fixed electrode, an application scenario of a small cavity size can be realized. Therefore, for miniaturized application scenarios, since the overall size of the capacitive film vacuum gauge is limited, a single capacitor fixed electrode solution is proposed, and the middle ring with a compromise between linearity and sensitivity is selected as the detection capacitor. Compared with the high-sensitivity inner circle capacitor in the prior art, the fixed capacitor provided in the embodiment of the present application can obtain higher linearity and higher temperature stability. In addition, by adjusting the inner diameter R24n and the outer diameter R24w of the third annular electrode 24 within the range of 0.2 to 0.8 times of R0, the cavity size and the plate spacing are coordinated and matched. Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the spirit and scope of the present application. In this way, if these modifications and variations of the present application belong to the scope of the claims of the present application and their equivalent technologies, the present application is also intended to include these changes and variations.

Claims

1. A fixed electrode, applied to a capacitive thin film vacuum gauge; characterized in that: The fixed electrode comprises: Support plate; An electrode layer is disposed on the support plate; The electrode layer comprises: a compensating electrode, a first annular electrode and a second annular electrode which are co-centered; wherein the first annular electrode is annular and spaced around the periphery of the compensating electrode, and the second annular electrode is annular and spaced around the periphery of the first annular electrode; The compensation electrode is connected to the second annular electrode via at least one first connecting portion, and the at least one first connecting portion is insulated from the first annular electrode; The first annular electrode comprises: a plurality of first sub-annular electrodes divided along a circumferential direction; the plurality of first sub-annular electrodes are connected by at least one second connecting portion, and the at least one second connecting portion is insulated from the compensation electrode and the second annular electrode; the at least one first connecting portion is arranged in the electrode layer, and each of the at least one first connecting portion is arranged in a gap between two adjacent first sub-annular electrodes; or The at least one first connection portion is arranged on the side of the support plate away from the electrode layer; the support plate has at least one through hole group; the at least one first connection portion corresponds to the at least one through hole group one by one; each through hole group in the at least one through hole group includes: a first through hole and a second through hole; in each of the through hole groups, the first through hole is filled with a first conductive portion, the second through hole is filled with a second conductive portion, the first end of the first conductive portion is connected to the compensation electrode, the first end of the second conductive portion is connected to the second annular electrode, and the second end of the first conductive portion is connected to the second end of the second conductive portion through the corresponding first connection portion.

2. The fixed electrode according to claim 1, characterized in that The fixed electrode comprises: a plurality of first connecting portions; The compensation electrode comprises: a plurality of compensation sub-electrodes divided along a circumferential direction; wherein the plurality of compensation sub-electrodes correspond one-to-one to the plurality of first connection portions; Each compensation sub-electrode of the plurality of compensation sub-electrodes is connected to the second annular electrode through the corresponding first connecting portion.

3. The fixed electrode according to claim 2, characterized in that Each of the first connecting portions extends along a radius direction of a set circle, and the set circle is co-centered with the second annular electrode; A first angle is formed between each of the first connecting portions and the line connecting the center of the circle, and at least two of the first angles are the same.

4. The fixed electrode according to claim 3, characterized in that: The plurality of compensation sub-electrodes are evenly divided along the circumferential direction, and each of the first connecting portions is connected to a midpoint of an outer arc of a corresponding compensation sub-electrode.

5. The fixed electrode according to any one of claims 1 to 4, characterized in that: The at least one second connection portion is disposed on the electrode layer, and each of the at least one second connection portion is disposed in a gap between two adjacent compensation sub-electrodes.

6. The fixed electrode according to claim 5, characterized in that The fixed electrode comprises: a plurality of second connecting parts; the plurality of first sub-annular electrodes correspond one to one with the plurality of second connecting parts; The second connecting parts extend along the radius direction of a set circle to the center of the circle and are connected to each other. The set circle is co-centered with the second annular electrode.

7. The fixed electrode according to claim 6, characterized in that: A second angle is formed between every two adjacent second connection portions, and at least two of the second angles are the same.

8. The fixed electrode according to claim 7, characterized in that: The plurality of first sub-annular electrodes are evenly divided along the circumferential direction, and each of the second connecting portions is connected to the midpoint of the inner arc of the corresponding first sub-annular electrode.

9. The fixed electrode according to any one of claims 1 to 4, characterized in that: When the compensation electrode includes a plurality of compensation sub-electrodes divided along a circumferential direction, the support plate has a plurality of through-hole groups; the plurality of compensation sub-electrodes correspond one to one to the plurality of through-hole groups; The compensation sub-electrode is connected to the second annular electrode through a first conductive portion, a second conductive portion and a first connecting portion corresponding to the through hole group.

10. The fixed electrode according to any one of claims 1 to 4, characterized in that: The support plate is circular in shape, and the support plate and the second annular electrode are cocentric; The inner diameter and the outer diameter of the first annular electrode are in the range of 0.4R0 to 0.8R0, and the width of the second annular electrode in the radial direction is not greater than 0.1R0, where R0 represents the diameter of the support plate.

11. The fixed electrode according to claim 10, characterized in that: The contour of the orthographic projection of the compensation electrode on the support plate is annular, and the outer diameter of the compensation electrode is not greater than 0.2R0; Alternatively, the contour of the orthographic projection of the compensation electrode on the support plate is circular, and the diameter of the compensation electrode is not greater than 0.2R0.

12. The fixed electrode according to claim 10, characterized in that: A width of at least one of the first connection portion and the second connection portion is not greater than 0.05R0.

13. The fixed electrode according to claim 10, characterized in that: 50mm≤R0≤70mm.

14. The fixed electrode according to any one of claims 1 to 4, characterized in that: The edge of the orthographic projection of at least one of the compensation electrode, the first annular electrode, and the second annular electrode on the support plate is at least one of a curved shape, a sawtooth shape, and a wavy shape.

15. A capacitive thin film vacuum gauge, characterized in that: include: A housing, comprising a receiving cavity; an elastic diaphragm, wherein the elastic diaphragm separates the accommodating cavity into a measuring cavity and a reference cavity; A connecting port, the connecting port being in communication with the measuring cavity; The fixed electrode according to any one of claims 1 to 14, wherein the fixed electrode is fixedly installed in the reference cavity, the fixed electrode is parallel to the elastic diaphragm, and the electrode layer is arranged facing one side of the elastic diaphragm; Wherein, the fixed electrode and the elastic diaphragm form a variable capacitor.

16. An electronic device, characterized in that: It comprises a capacitive thin film vacuum gauge, wherein the capacitive thin film vacuum gauge comprises a fixed electrode as described in any one of claims 1-14.

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