CN115790954A

CN115790954A - Capacitive pressure core

Info

Publication number: CN115790954A
Application number: CN202211689326.0A
Authority: CN
Inventors: 谭佳欢; 钟海
Original assignee: Avic Optoelectronics Huayi Shenyang Electronic Technology Co ltd
Current assignee: Avic Optoelectronics Huayi Shenyang Electronic Technology Co ltd
Priority date: 2022-12-27
Filing date: 2022-12-27
Publication date: 2023-03-14

Abstract

The invention provides a capacitive pressure core body, relates to the technical field of pressure sensors, and aims to optimize the structure of the capacitive pressure core body to a certain extent and improve the pressure measuring range and overload capacity. The invention provides a capacitive pressure core body which comprises a base, a movable electrode assembly, a sealing piece, a substrate, a fixed electrode assembly and a communication feedback assembly, wherein the movable electrode assembly is arranged on the base; the base is made of metal materials, an elastic membrane is formed on one side of the base, and a pressure guide part extending to the elastic membrane is formed on the other side of the base along the thickness direction of the base; the movable electrode assembly is arranged on one side, away from the pressure guiding part, of the elastic membrane, two ends of the sealing piece are respectively connected with the substrate and the movable electrode assembly to form an installation cavity, and the fixed electrode assembly is connected with one side of the substrate and is positioned in the installation cavity; the communication feedback assembly is respectively in line connection with the movable electrode assembly and the fixed electrode assembly and is positioned on one side, away from the mounting cavity, of the substrate.

Description

Capacitive pressure core

Technical Field

The invention relates to the technical field of pressure sensors, in particular to a capacitive pressure core body.

Background

The capacitance pressure sensor is a polar distance changing capacitance sensor, which generally adopts a circular pressure sensing diaphragm as a movable electrode of a capacitor, when the diaphragm is deformed by sensing pressure, capacitance formed between the diaphragm and a fixed electrode is changed, and an electric signal in a certain relation with voltage can be output through a measuring circuit.

With the development of low-temperature glass sealing technology, ceramic technology and thick-film screen technology, a ceramic capacitor pressure sensor based on ceramic capacitor technology appears, which adopts a fixed ceramic base and a movable ceramic diaphragm structure, and the movable diaphragm is sealed and fixed with the base through glass slurry and other modes. The inner side between the two is printed with an electrode pattern, thereby forming a variable capacitor, when the medium pressure born on the diaphragm changes, the capacitance between the two changes, and the signal is converted and conditioned by the conditioning chip and then output to the later stage for use.

The ceramic capacitive pressure sensor adopts a ceramic diaphragm as a sensitive element, has the characteristics of extremely high corrosion resistance, good elasticity, small hysteresis creep, small influence by temperature, simple structure, low power consumption, strong overload resistance, vibration resistance, radiation resistance and the like, and has wide market application prospect, but the ceramic is a brittle material, cannot be subjected to finish machining, has low strength and poor toughness, and can only be applied to occasions with the pressure range not exceeding 10Mpa and small overload capacity.

Therefore, it is desirable to provide a capacitive pressure core to solve the problems of the prior art to some extent.

Disclosure of Invention

The invention aims to provide a capacitive pressure core body, which aims to optimize the structure of the capacitive pressure core body to a certain extent and improve the pressure measuring range and overload capacity.

The invention provides a capacitive pressure core body which comprises a base, a movable electrode assembly, a sealing piece, a substrate, a fixed electrode assembly and a communication feedback assembly, wherein the base is provided with a plurality of through holes; the base is made of metal materials, an elastic membrane is formed on one side of the base, and a pressure guiding part extending to the elastic membrane is formed on the other side of the base along the thickness direction of the base; the movable electrode assembly is arranged on one side, away from the pressure guiding part, of the elastic membrane, two ends of the sealing piece are respectively connected with the substrate and the movable electrode assembly to form an installation cavity, and the fixed electrode assembly is connected with one side of the substrate and is positioned in the installation cavity; the communication feedback assembly is respectively in line connection with the movable electrode assembly and the fixed electrode assembly and is positioned on one side of the substrate, which deviates from the mounting cavity.

Wherein the movable electrode assembly includes an insulating layer, a first electrode layer, and a protective layer; the insulating layer is formed on one side, away from the pressure guiding portion, of the base, the first electrode layer is formed on the insulating layer, and the protective layer covers the first electrode layer.

Specifically, the first electrode layer comprises a voltage sensing part and a first connecting part; the protective layer covers the pressure sensing portion, a first expansion portion is formed at one end, far away from the pressure sensing portion, of the first connecting portion, and the first expansion portion is used for being in butt joint with the communication feedback assembly.

Specifically, the protective layer is formed by printing and firing glass glaze slurry through a thick film screen printing process.

Further, the fixed electrode assembly is disposed opposite to the movable electrode assembly, and the fixed electrode assembly includes a measurement electrode layer and a reference electrode layer having the same area; the reference electrode layer comprises an annular part and a second connecting part, the measuring electrode layer comprises a central part and a third connecting part, the central part is arranged in the annular part, an opening is formed in the annular part, and one end of the third connecting part extends out of the opening; one end of the second connecting portion, which is far away from the annular portion, is provided with a second expanding portion, one end of the third connecting portion, which is far away from the central portion, is provided with a third expanding portion, and the second expanding portion and the third expanding portion are used for being in butt joint with the communication feedback assembly.

Further, the communication feedback assembly comprises a first lead, a second lead, a third lead and a signal conditioning board; the signal conditioning board is arranged on one side, away from the mounting cavity, of the substrate, one end of the first lead is connected with the first extension part, the other end of the first lead is connected with the signal conditioning board, one end of the second lead is connected with the second extension part, the other end of the second lead is connected with the signal conditioning board, one end of the third lead is connected with the third extension part, and the other end of the third lead is connected with the signal conditioning board.

Furthermore, the connected feedback assembly further comprises an AS IC chip, and the AS IC chip is arranged on the signal conditioning plate and used for conditioning the output capacitance signal.

The substrate is made of ceramic materials, and a vent hole is formed in the substrate.

Specifically, the insulating layer is made of a glass material, the sealing piece is made of a low-melting glass material, and a through hole is formed in the position, corresponding to the first expansion portion, of the sealing piece.

Further, the thickness of the elastic membrane is smaller than that of the substrate.

Compared with the prior art, the capacitive pressure core body provided by the invention has the following advantages:

the invention provides a capacitive pressure core body which comprises a base, a movable electrode assembly, a sealing piece, a substrate, a fixed electrode assembly and a communication feedback assembly, wherein the movable electrode assembly is arranged on the base; the base is made of metal materials, an elastic membrane is formed on one side of the base, and a pressure-guiding part extending to the elastic membrane is formed on the other side of the base along the thickness direction of the base; the movable electrode assembly is arranged on one side, away from the pressure guiding part, of the elastic membrane, two ends of the sealing piece are respectively connected with the substrate and the movable electrode assembly to form an installation cavity, and the fixed electrode assembly is connected with one side of the substrate and is positioned in the installation cavity; the communication feedback assembly is respectively in line connection with the movable electrode assembly and the fixed electrode assembly and is positioned on one side of the substrate, which is far away from the mounting cavity.

Therefore, through the base made of the metal material, the base can be directly butted with the pressure interface in modes of welding and the like in actual application, so that the base and the pressure interface form an integrated interface, any bonding glue and sealing material are not needed, the failure of the whole structure caused by the problems of poor strength, aging, leakage of the sealing material and the like of the bonding glue is avoided, and the sealing performance, overload capacity and reliability of the whole pressure core body under a high-pressure environment can be guaranteed to a certain extent.

Moreover, the capacitive pressure core body directly forms the pressure guiding part and the elastic diaphragm on the base, so that the pressure measuring range and the overload capacity can be improved, and the whole pressure core body is suitable for severe environment working conditions.

During actual operation, liquid enters the pressure guiding portion to generate pressure on the elastic membrane, the elastic membrane deforms under the action of the pressure, accordingly, capacitance formed between the movable electrode assembly and the fixed electrode assembly on the cover plate changes, a pressure measurement signal is generated, feedback output is conducted through the feedback assembly, and measurement of the pressure is achieved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

Fig. 1 is a schematic overall structural diagram of a capacitive pressure core provided in an embodiment of the present invention;

FIG. 2 is a cross-sectional view of a capacitive pressure core structure provided by an embodiment of the present invention;

fig. 3 is a schematic structural diagram of a first implementation of a base in a capacitive pressure core according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of a second implementation of a base in a capacitive pressure core according to an embodiment of the present invention;

fig. 5 is a schematic structural diagram of a movable electrode assembly in the capacitive pressure core provided in the embodiment of the present invention;

fig. 6 is a schematic structural diagram of a fixed electrode assembly in the capacitive pressure core according to an embodiment of the present invention.

In the figure: 1-a base; 101-a pressure-leading part; 102-an elastic membrane; 103-a threaded joint; 2-sealing the connecting piece; 3-an insulating layer; 4-a first electrode layer; 401-pressure sensitive part; 402-a first connection; 403-a first expansion; 5-a protective layer; 6-measuring the electrode layer; 601-a central portion; 602-a third connection; 603-a third extension; 7-a reference electrode layer; 701-an annular part; 7011-open mouth; 702 — a second connection; 703-a second extension; 8-a substrate; 801-a vent hole; 9-a first lead; 10-a second lead; 11-a third lead; 12-a signal conditioning board; 13-AS IC chip.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all the embodiments. The components of the embodiments of the present application, generally described and illustrated in the figures herein, can be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the present application, presented in the accompanying drawings, is not intended to limit the scope of the claimed application, but is merely representative of selected embodiments of the application. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present application without making any creative effort, shall fall within the protection scope of the present application.

In the description of the embodiments of the present application, it should be noted that the terms "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on orientations or positional relationships shown in the drawings or orientations or positional relationships that the present invention is used to place as usual, and are only used for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

Furthermore, the terms "horizontal", "vertical" and the like do not imply that the components are required to be absolutely horizontal or pendant, but rather may be slightly inclined. For example, "horizontal" merely means that the direction is more horizontal than "vertical" and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.

In the description of the embodiments of the present application, it should also be noted that, unless otherwise explicitly stated or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

As used herein, the term "and/or" includes any one of the associated listed items and any combination of any two or more of the items.

For ease of description, spatial relationship terms such as "above 8230; …," upper "," above 8230; \8230;, "below" and "lower" may be used herein to describe the relationship of one element to another element as illustrated in the figures. Such spatial relationship terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures.

The terminology used herein is for the purpose of describing various examples only and is not intended to be limiting of the disclosure. The singular forms are also intended to include the plural forms unless the context clearly indicates otherwise. The terms "comprises," "comprising," and "having" specify the presence of stated features, quantities, operations, elements, components, and/or combinations thereof, but do not preclude the presence or addition of one or more other features, quantities, operations, components, elements, and/or combinations thereof.

Variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, may be expected. Thus, the examples described herein are not limited to the particular shapes shown in the drawings, but include changes in shape that occur during manufacturing.

The features of the examples described herein may be combined in various ways that will be apparent after understanding the disclosure of this application. Further, while the examples described herein have a variety of configurations, other configurations are possible, as will be apparent after understanding the disclosure of the present application. In addition, technical solutions between the embodiments may be combined with each other, but must be based on the realization of the technical solutions by a person skilled in the art, and when the technical solutions are contradictory to each other or cannot be realized, such a combination should not be considered to exist, and is not within the protection scope claimed in the present application.

As shown in fig. 1-3, the present invention provides a capacitive pressure core, which includes a base 1, a movable electrode assembly, a sealing member 2, a substrate 8, a fixed electrode assembly, and a communication feedback assembly; the base 1 is made of metal material, one side of the base 1 is formed with an elastic membrane 102, and the other side of the base 1 is formed with a pressure-leading part 101 extending to the elastic membrane 102 along the thickness direction of the base 1; the movable electrode assembly is arranged on one side of the elastic membrane 102, which is far away from the pressure guiding part 101, two ends of the sealing piece 2 are respectively connected with the base plate 8 and the movable electrode assembly to form a mounting cavity, and the fixed electrode assembly is connected with one side of the base plate 8 and is positioned in the mounting cavity; the communication feedback assembly is respectively in line connection with the movable electrode assembly and the fixed electrode assembly and is positioned on one side of the substrate 8, which is far away from the installation cavity.

according to the capacitive pressure core body, the base 1 made of the metal material can be directly butted with the pressure interface in a welding mode and other modes in practical application, so that the capacitive pressure core body and the pressure interface form an integrated interface, any bonding glue and sealing material are not needed, the problem that the whole structure fails due to poor strength and aging of the bonding glue, leakage of the sealing material and the like is avoided, and the sealing performance, overload capacity and reliability of the whole pressure core body in a high-pressure environment can be further ensured to a certain extent.

In addition, the capacitive pressure core body directly forms the pressure-leading part 101 and the elastic diaphragm 102 on the base 1, so that the pressure measuring range and the overload capacity can be improved, and the whole pressure core body is suitable for severe environment working conditions.

In actual operation, liquid enters the pressure guiding part 101 to generate pressure on the elastic diaphragm 102, the elastic diaphragm 102 deforms under the action of the pressure, so that the electrode gap between the movable electrode assembly and the fixed electrode assembly on the cover plate is reduced, capacitance of the capacitor core body is changed, and the capacitance change is proportional to the pressure, so that the capacitance change is converted into a pressure measurement signal through the communication feedback assembly to be fed back and output, and the measurement of the pressure is realized.

It should be added here that the thickness of the elastic membrane 102 in the present application is preferably smaller than the thickness of the substrate 8. The thickness of the flexible diaphragm 102 in this application may also be determined by the pressure measurement range, with the greater the thickness of the flexible diaphragm 102, the greater the pressure measurement range.

As shown in fig. 4, in some embodiments, the base 1 of the present application can be further processed into an integrated base 1 integrating the elastic diaphragm 102, the pressure guiding portion 101 and the threaded joint 103, so as to be able to more conveniently interface with the pressure interface.

It should be added here that the base 1 in this application is made of stainless steel material, and preferably, stainless steel of 17-4 PH. The elastic diaphragm 102 and the pressure guiding part 101 are directly formed after processing, the pressure guiding part 101 is a pressure guiding groove, liquid directly enters the pressure guiding groove to be in contact with the pressure sensing part of the elastic diaphragm 102, and pressure is applied to the elastic diaphragm 102 to enable the elastic diaphragm to deform, so that the pressure is measured.

It should be further added that, since the movable electrode assembly is required to be disposed on the back pressure side of the elastic diaphragm 102 in the present application, operations such as cleaning and plasma treatment are required to be performed on the back pressure side of the elastic diaphragm 102 before the movable electrode assembly is formed in the present application, so as to ensure the smoothness of the back pressure side of the elastic diaphragm 102.

It is understood that, as shown in fig. 2 in conjunction with fig. 5, the movable electrode assembly in the present application includes an insulating layer 3, a first electrode layer 4, and a protective layer 5; the insulating layer 3 is formed on one side of the base 1, which is far away from the pressing part 101, the first electrode layer 4 is formed on the insulating layer 3, and the protective layer 5 covers the first electrode layer 4.

Preferably, the insulating layer 3 in the present application is formed of a glass material, and after the back pressure side treatment of the elastic diaphragm 102 is completed, an insulating glass paste is printed on the elastic diaphragm 102 by a thick film screen printing technique, and then dried and sintered at a high temperature to form the above-described insulating layer 3.

In the present application, the insulating layer 3 covers all the elastic membrane 102, and the sealing member 2 is formed on the insulating layer 3, and further preferably, the sealing member 2 in the present application is formed of a low-melting glass material, and the sealing member 2 is annular, and a through hole is formed at a position of the sealing member 2 corresponding to the first expansion portion 403, so that the first lead 9 can be smoothly communicated with the first electrode layer 4 through the through hole.

It can be understood that the sealing member 2 in the present application is formed by sintering, and the sintering temperature is lower than 580 ℃, and the sealing member 2 can protect the fixed electrode assembly on the substrate 8 and the first electrode layer 4 on the elastic membrane 102, and can form an integrated structure with the substrate 8 and the base 1 by sintering, so as to improve the stability of the core body.

Alternatively, as shown in fig. 5, the first electrode layer 4 in the present application includes a voltage sensing part 401 and a first connection part 402; the protective layer 5 covers the pressure sensing part 401, and a first expansion part 403 is formed at one end of the first connection part 402 away from the pressure sensing part 401, and the first expansion part 403 is used for abutting with the communication feedback assembly.

The diameter of the first expanded portion 403 in the present application is larger than the width of the first connection portion 402, so that connection with one end of a communication feedback member, i.e., a first lead 9 described below, can be facilitated.

It should be added here that the first electrode layer 4 is formed by sintering a conductor paste on the insulating layer 3 by a thick-film screen printing process in the present application.

Accordingly, the protective layer 5 in the present application is formed by printing and firing a glass frit paste by a thick film screen printing process, and the protective layer 5 in the present application mainly covers the pressure sensitive portion 401 of the first electrode layer 4.

As shown in fig. 2 in conjunction with fig. 6, the fixed electrode assembly is disposed opposite to the movable electrode assembly in the present application, and the fixed electrode assembly includes a measurement electrode layer 6 and a reference electrode layer 7 having the same area; the reference electrode layer 7 comprises an annular part 701 and a second connecting part 702, the measuring electrode layer 6 comprises a central part 601 and a third connecting part 602, the central part 601 is arranged in the annular part 701, the annular part 701 is provided with an opening 7011, and one end of the third connecting part 602 extends out of the opening 7011; the end of the second connecting portion 702 away from the annular portion 701 is formed with a second expanded portion 703, the end of the third connecting portion 602 away from the central portion 601 is formed with a third expanded portion 603, and the second expanded portion 703 and the third expanded portion 603 are used for interfacing with a communication feedback assembly.

The substrate 8 in the present application is made of a ceramic material, and preferably, is an alumina ceramic. In some embodiments, the substrate 8 is not provided with the vent hole 801, and in this way, the susceptor 1 and the substrate 8 are sintered at high temperature in a vacuum environment to form a capacitive pressure core with a vacuum medium inside, and the pressure core can be used for measuring absolute pressure.

As shown in fig. 1 and fig. 2, in the illustrated embodiment, the base plate 8 in the present application is provided with a vent hole 801, and the vent hole 801 can communicate the inside of the pressure core body with the outside atmosphere, so that the pressure core body can be used for measuring gauge pressure.

Measuring electrode layer 6 and reference electrode layer 7 in this application are passed through thick film screen printing technology by conductor thick liquid and are sintered to base plate 8 on, and because reference electrode layer 7 in this application includes annular portion, consequently, can form annular two capacitor structure's basic electrode to can reduce the measurement error that the nonlinearity of core output and temperature arouse to a certain extent, played the temperature self-compensation effect.

Further preferably, the reference electrode layer 7 and the measurement electrode layer 6 in the present application have the same area, so that the initial capacitance values of the test capacitance and the reference capacitance can be equal, and the temperature effect of the temperature on the reference electrode layer 7 and the measurement electrode layer 6 is consistent, and the differential capacitance reduces the influence of the temperature and the nonlinear error.

As shown in fig. 6, in the present application, the diameter of the second expanded portion 703 formed with reference to the electrode layer 7 is larger than the width of the second connection portion 702, and the diameter of the third expanded portion 603 formed with reference to the measurement electrode layer 6 is larger than the width of the third connection portion 602, so that the connection of the second lead 10 and the third lead 11 can be facilitated.

It is understood that, as shown in fig. 1 in conjunction with fig. 2, the feed-through feedback assembly in the present application includes a first lead 9, a second lead 10, a third lead 11, and a signal conditioning board 12; the signal conditioning board 12 is disposed on one side of the substrate 8 departing from the mounting cavity, one end of the first lead 9 is connected to the first extension portion 403, the other end of the first lead is connected to the signal conditioning board 12, one end of the second lead 10 is connected to the second extension portion 703, the other end of the second lead is connected to the signal conditioning board 12, one end of the third lead 11 is connected to the third extension portion 603, and the other end of the third lead is connected to the signal conditioning board 12.

The signal conditioning plate 12 in the application is connected with one side of the base plate 8 departing from the fixed electrode assembly through bonding, and the reference electrode layer 7, the measuring electrode layer 6 and the first electrode layer 4 can be directly connected with the signal conditioning plate 12 through the first lead 9, the second lead 10 and the third lead 11, so that the lead length can be reduced, and the lead capacitance and the parasitic capacitance are reduced.

Preferably, AS shown in fig. 1 and fig. 2, the connected feedback assembly further includes an AS ic chip 13, where the AS ic chip 13 is disposed on the signal conditioning board 12 for conditioning the output capacitance signal.

It can be understood that the AS ic chip 13 in the present application can receive the capacitance signal, and output a current or voltage signal proportional to the measured medium pressure after conditioning, so AS to complete the measurement of the pressure.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and should not be taken as limiting the scope of the present invention, which is intended to cover any modifications, equivalents, improvements, etc. within the spirit and scope of the present invention.

Claims

1. A capacitance type pressure core body is characterized by comprising a base, a movable electrode assembly, a sealing piece, a substrate, a fixed electrode assembly and a communication feedback assembly;

the base is made of a metal material, an elastic membrane is formed on one side of the base, and a pressure guide part extending to the elastic membrane is formed on the other side of the base along the thickness direction of the base;

the movable electrode assembly is arranged on one side, away from the pressure guiding part, of the elastic membrane, two ends of the sealing piece are respectively connected with the base plate and the movable electrode assembly to form an installation cavity, and the fixed electrode assembly is connected with one side of the base plate and located in the installation cavity;

the communication feedback assembly is respectively in line connection with the movable electrode assembly and the fixed electrode assembly and is positioned on one side of the substrate, which deviates from the mounting cavity.

2. A capacitive pressure core according to claim 1, wherein the movable electrode assembly comprises an insulating layer, a first electrode layer and a protective layer;

the insulating layer is formed on one side, away from the pressure guiding portion, of the base, the first electrode layer is formed on the insulating layer, and the protective layer covers the first electrode layer.

3. A capacitive pressure core according to claim 2, wherein the first electrode layer comprises a pressure sensing portion and a first connection portion;

the protective layer covers the pressure sensing portion, a first expansion portion is formed at one end, far away from the pressure sensing portion, of the first connecting portion, and the first expansion portion is used for being in butt joint with the communication feedback assembly.

4. A capacitive pressure core according to claim 2, wherein the protective layer is formed by printing and firing a glass frit paste by a thick film screen printing process.

5. A capacitive pressure core according to claim 3, wherein the stationary electrode assembly is arranged opposite the movable electrode assembly and comprises a measuring electrode layer and a reference electrode layer of the same area;

the reference electrode layer comprises an annular part and a second connecting part, the measuring electrode layer comprises a central part and a third connecting part, the central part is arranged in the annular part, an opening is formed in the annular part, and one end of the third connecting part extends out of the opening;

one end of the second connecting portion, which is far away from the annular portion, is provided with a second expanding portion, one end of the third connecting portion, which is far away from the central portion, is provided with a third expanding portion, and the second expanding portion and the third expanding portion are used for being in butt joint with the communication feedback assembly.

6. A capacitive pressure core according to claim 5, wherein the feed-through feedback assembly comprises a first lead, a second lead, a third lead and a signal conditioning plate;

the signal conditioning board is arranged on one side, away from the mounting cavity, of the substrate, one end of the first lead is connected with the first extension part, the other end of the first lead is connected with the signal conditioning board, one end of the second lead is connected with the second extension part, the other end of the second lead is connected with the signal conditioning board, one end of the third lead is connected with the third extension part, and the other end of the third lead is connected with the signal conditioning board.

7. The capacitive pressure core according to claim 6, wherein the feed-through feedback assembly further comprises an ASIC chip disposed on the signal conditioning plate for conditioning the output capacitive signal.

8. The capacitive pressure core according to claim 1, wherein the substrate is made of a ceramic material and has a vent hole formed therein.

9. A capacitive pressure core according to claim 3, wherein the insulating layer is formed from a glass material and the seal is formed from a low melting glass material, the seal being perforated in correspondence with the first extension.

10. A capacitive pressure core according to claim 1, characterized in that the thickness of the elastic membrane is smaller than the thickness of the substrate.