Pressure sensor

Abstract

The invention discloses a pressure sensor. The working modes of the pressure sensor comprise a resonance mode and a dynamic pressure mode; the pressure sensor comprises a substrate, the top of which is provided with a pressure reference cavity; a dielectric layer; a vibrating membrane; the first electrode layer comprises a first middle electrode and a first edge electrode surrounding the first middle electrode, the first middle electrode is connected with the first middle electrode bonding pad, and the first edge electrode is connected with the first edge electrode bonding pad; the piezoelectric layer comprises a middle piezoelectric film and an edge piezoelectric film surrounding the middle piezoelectric film; the second electrode layer comprises a second middle electrode and a second edge electrode surrounding the second middle electrode, the second middle electrode is connected with the second middle electrode bonding pad, and the second edge electrode is connected with the second edge electrode bonding pad. The pressure sensor provided by the invention can realize dual-mode measurement of dynamic pressure and vacuum pressure.

Description

Technical Field

[0001] The present invention relates to the technical field of sensors, and in particular to a pressure sensor. Background Art

[0002] Dynamic pressure and vacuum pressure measurement are widely used in industrial control equipment. Among them, Micro-Electro-Mechanical Systems (MEMS) sensors are widely studied and used due to their small size, low power consumption, and easy mass production.

[0003] In the existing technology, dynamic pressure measurement can be achieved by sensing the deformation of the substrate through the piezoelectric film material integrated in the substrate and converting it into an electrical signal proportional to the pressure amplitude; or the vibration damping of the resonator under different ambient pressures can be used to achieve vacuum pressure measurement.

[0004] However, in the prior art, dynamic pressure testing and vacuum pressure testing require two separate sensors, and there is a lack of a sensor that can perform both dynamic pressure measurement and vacuum pressure measurement. Summary of the Invention

[0005] The present invention provides a pressure sensor for realizing dual-mode measurement of dynamic pressure and vacuum pressure by utilizing the same sensitive structure.

[0006] According to one aspect of the present invention, a pressure sensor is provided, wherein the operating modes thereof include a resonance mode and a dynamic pressure mode; the pressure sensor comprises:

[0007] A substrate, wherein a pressure reference cavity is provided on the top of the substrate;

[0008] a dielectric layer, located on the substrate and sealing the pressure reference cavity;

[0009] a vibrating membrane located on a side of the dielectric layer away from the substrate; the vibrating membrane oscillates out of the plane in the resonance mode and does not actively vibrate in the dynamic pressure mode; the vibrating membrane is provided with a first ground pad, a second ground pad, a first edge electrode pad, a first middle electrode pad, a second edge electrode pad, and a second middle electrode pad; wherein the first ground pad and the second ground pad are grounded;

[0010] a first electrode layer located on a side of the vibrating membrane away from the substrate; the first electrode layer comprising a first middle electrode and a first edge electrode surrounding the first middle electrode, the first middle electrode being connected to the first middle electrode pad, and the first edge electrode being connected to the first edge electrode pad;

[0011] a piezoelectric layer located on a side of the first electrode layer away from the substrate; the piezoelectric layer comprising an intermediate piezoelectric film and an edge piezoelectric film surrounding the intermediate piezoelectric film; the piezoelectric layer detecting the vibration displacement caused by the vibrating membrane in the resonant mode to measure vacuum pressure, and detecting the dynamic deformation in the dynamic pressure mode to measure dynamic pressure;

[0012] a second electrode layer located on a side of the piezoelectric layer away from the substrate; the second electrode layer includes a second intermediate electrode and a second edge electrode surrounding the second intermediate electrode, the second intermediate electrode is connected to the second intermediate electrode pad, and the second edge electrode is connected to the second edge electrode pad.

[0013] Optionally, in the resonance mode, the thickness and size of the vibration membrane and the depth of the pressure reference cavity are adjusted to control the measuring range of the pressure sensor.

[0014] Optionally, in the resonance mode, the first middle electrode and the second middle electrode are actuating electrodes, and the first edge electrode and the second edge electrode are detection electrodes.

[0015] Optionally, the shape of the pressure reference chamber is circular, polygonal or a combination thereof.

[0016] Optionally, the pressure inside the pressure reference chamber is lower than the set pressure.

[0017] Optionally, the vibration membrane is attached to the dielectric layer and airtightly packaged; the dielectric layer and the substrate layer are attached to each other and airtightly packaged; and the vibration membrane is insulated from the first electrode layer.

[0018] Optionally, the gap between the first intermediate electrode and the first edge electrode is greater than a first set distance.

[0019] Optionally, the gap between the second intermediate electrode and the second edge electrode is greater than the first set distance.

[0020] Optionally, the gap between the middle piezoelectric film and the edge piezoelectric film is greater than a second set distance, wherein the second set distance is smaller than the first set distance.

[0021] Optionally, the size of the first intermediate electrode is smaller than the size of the intermediate piezoelectric film, and the size of the second intermediate electrode is smaller than the size of the intermediate piezoelectric film;

[0022] The size of the first edge electrode is smaller than that of the edge piezoelectric film, and the size of the second edge electrode is smaller than that of the edge piezoelectric film.

[0023] Optionally, the material of the first intermediate electrode and the first edge electrode is at least one of copper, aluminum or gold.

[0024] Optionally, the material of the second intermediate electrode and the second edge electrode is at least one of copper, aluminum or gold.

[0025] Optionally, the material of the intermediate piezoelectric film is at least one of aluminum nitride, scandium aluminum nitride or zinc oxide; the material of the edge piezoelectric film is at least one of aluminum nitride, scandium aluminum nitride or zinc oxide; wherein the material of the intermediate piezoelectric film and the material of the edge piezoelectric film are the same or different.

[0026] The technical scheme of the embodiment of the present application is aimed at the contradiction of the sensor in the prior art which fails to measure dynamic pressure and vacuum pressure simultaneously, and the structure design of the pressure sensor is performed. Specifically, the pressure sensor comprises a substrate, a dielectric layer, a vibrating membrane, a first electrode layer, a piezoelectric layer and a second electrode layer which are arranged in layers, wherein the top of the substrate is provided with a pressure reference cavity; the vibrating membrane is provided with a first ground pad, a second ground pad, a first edge electrode pad, a first intermediate electrode pad, a second edge electrode pad and a second intermediate electrode pad; the first electrode layer comprises a first intermediate electrode and a first edge electrode surrounding the first intermediate electrode; the piezoelectric layer comprises an intermediate piezoelectric film and an edge piezoelectric film surrounding the intermediate piezoelectric film; and the second electrode layer comprises a second intermediate electrode and a second edge electrode surrounding the second intermediate electrode. The embodiment of the present application can have two working modes, i.e. a resonance mode and a dynamic pressure mode, according to different control modes, the vacuum pressure is measured in the resonance mode, and the dynamic pressure is measured in the dynamic pressure mode. Therefore, the pressure sensor provided by the embodiment of the present application realizes the integration of the measurement of dynamic pressure and static vacuum pressure by using only one sensitive structure, thereby realizing the fusion measurement of the two pressures by one sensitive structure.

[0027] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present application, nor is it used to limit the scope of the present application. Other features of the present application will become apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0029] Figure 1 A structural schematic diagram of a pressure sensor provided by the embodiment of the present application is shown in the figure;

[0030] Figure 2 A schematic structural diagram of an electrode pad provided by an embodiment of the present invention;

[0031] Figure 3 A schematic structural diagram of a first electrode layer provided in an embodiment of the present invention;

[0032] Figure 4 A schematic structural diagram of a second electrode layer provided in an embodiment of the present invention;

[0033] Figure 5 A schematic structural diagram of a piezoelectric layer provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0034] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0035] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0036] Figure 1 A schematic structural diagram of a pressure sensor provided by an embodiment of the present invention. Figure 2 A schematic structural diagram of an electrode pad provided in an embodiment of the present invention. Figure 3 A schematic structural diagram of a first electrode layer provided in an embodiment of the present invention. Figure 4 A schematic structural diagram of a second electrode layer provided in an embodiment of the present invention. Figure 5 This is a schematic diagram of the structure of a piezoelectric layer provided by an embodiment of the present invention. This embodiment is applicable to both the case of measuring dynamic pressure and the case of measuring vacuum pressure. Figure 1-Figure 5As shown, the pressure sensor includes: a substrate 1, a pressure reference cavity 1-1 is provided on the top of the substrate 1; a dielectric layer 2 is located on the substrate 1 and seals the pressure reference cavity 1-1; a vibration membrane 3 is located on the side of the dielectric layer 2 away from the substrate 1; the vibration membrane 3 oscillates outward in the resonance mode and does not actively vibrate in the dynamic pressure mode; a first ground pad 3-1, a second ground pad 3-2, a first edge electrode pad 3-4, a first intermediate electrode pad 3-3, a second edge electrode pad 3-6 and a second intermediate electrode pad 3-5 are provided on the vibration membrane 3; wherein the first ground pad 3-1 and the second ground pad 3-2 are grounded; a first electrode layer 4 is located on the side of the vibration membrane 3 away from the substrate 1; the first electrode layer 4 includes a first intermediate electrode 4-1 and a first edge electrode 4-2 surrounding the first intermediate electrode 4-1, The first intermediate electrode 4-1 is connected to the first intermediate electrode pad 3-3, and the first edge electrode 4-2 is connected to the first edge electrode pad 3-4; the piezoelectric layer 5 is located on the side of the first electrode layer 4 away from the substrate 1; the piezoelectric layer 5 includes an intermediate piezoelectric film 5-1 and an edge piezoelectric film 5-2 surrounding the intermediate piezoelectric film; the piezoelectric layer 5 detects the vibration displacement brought by the vibrating membrane 3 in the resonant mode to achieve the measurement of vacuum pressure, and detects the dynamic deformation in the dynamic pressure mode to achieve the measurement of dynamic pressure; the second electrode layer 6 is located on the side of the piezoelectric layer 5 away from the substrate 1; the second electrode layer 6 includes a second intermediate electrode 6-1 and a second edge electrode 6-2 surrounding the second intermediate electrode 6-1, the second intermediate electrode 6-1 is connected to the second intermediate electrode pad 3-5, and the second edge electrode 6-2 is connected to the second edge electrode pad 3-6.

[0037] Specifically, when the sensor is in a resonant state, slight pressure changes will cause the vibration characteristics of the vibrating membrane 3, such as frequency and amplitude, to change. These changes can be detected and converted into electrical signals. The vibrating membrane 3 does not actively resonate in the dynamic pressure mode, but responds in real time to the externally applied dynamic pressure. The pressure sensor measures the dynamic pressure by detecting the deformation of the membrane. In an embodiment of the present invention, in the resonant mode, the vibrating membrane 3 vibrates outward, and the vibration frequency is far away from the operating frequency bandwidth of the dynamic pressure measurement when working in the dynamic pressure mode. At this time, the edge piezoelectric film 5-2 and the central piezoelectric film 5-1 provide the vibration pickup signal and the actuation signal required by the diaphragm vibration control circuit.

[0038] In some embodiments, substrate 1 refers to the base structure of the pressure sensor, typically made of semiconductor material or other suitable material. Substrate 1 provides physical support and is used to integrate other components such as pressure reference cavity 1-1, dielectric layer 2, etc. Pressure reference cavity 1-1 refers to a closed space located on top of substrate 1, used to provide a known pressure reference. The presence of pressure reference cavity 1-1 enables the pressure sensor to measure relative to this reference pressure, thereby improving the accuracy of the measurement. Dielectric layer 2 refers to a structure located on substrate 1, sealing pressure reference cavity 1-1. Dielectric layer 2 is typically made of insulating material, serving the purpose of protection and isolation, to prevent external environment from affecting pressure reference cavity 1-1. Diaphragm 3 refers to a deformable membrane located on the side of dielectric layer 2 away from substrate 1. Diaphragm 3 continuously oscillates in-plane under the control of the matching circuit in resonance mode, but does not actively vibrate in dynamic pressure mode. The movement of diaphragm 3 is used to sense pressure changes. The pads refer to metal contacts used to connect the circuit. Diaphragm 3 is provided with multiple pads, among which the first ground pad 3-1 and the second ground pad 3-2 are used for grounding, providing the reference potential of the circuit; the first edge electrode pad 3-4 and the first intermediate electrode pad 3-3 are used to connect the corresponding electrodes of the first electrode layer 4; the second edge electrode pad 3-6 and the second intermediate electrode pad 3-5 are used to connect the corresponding electrodes of the second electrode layer 6.

[0039] Specifically, piezoelectric layer 5 refers to the structure in the pressure sensor used to convert mechanical strain into electrical signals. The working principle of piezoelectric layer 5 is based on the piezoelectric effect, i.e. certain materials produce electric charges when subjected to mechanical pressure or deformation. Commonly used materials for piezoelectric layer 5 can include aluminum nitride, scandium aluminum nitride, zinc oxide, lead zirconium titanate, polyvinylidene fluoride, and sodium zirconium titanate, etc. materials with piezoelectric effect. Piezoelectric layer 5 includes intermediate piezoelectric film and edge piezoelectric film. The intermediate piezoelectric film refers to the central piezoelectric structure used to detect the displacement of diaphragm 3. The intermediate piezoelectric film directly responds to the displacement caused by diaphragm 3. The deformation of the intermediate piezoelectric film causes the generation of electric charges, thereby generating electrical signals. The edge piezoelectric film refers to the piezoelectric structure surrounding the intermediate piezoelectric film. The edge piezoelectric film can provide additional sensitivity and signal enhancement. The edge part helps to improve the overall performance and enhance the response to pressure changes.

[0040] In some embodiments, the material of the electrode layer can be high-conductivity metal materials such as copper, aluminum, gold, etc. In the embodiments of the present application, the electrode layer includes first electrode layer 4 and second electrode layer 6. First electrode layer 4 includes first intermediate electrode 4-1 and first edge electrode 4-2. In Figure 1In the illustrated perspective, the first electrode layer 4 can also be referred to as a lower electrode layer 4, the first intermediate electrode 4-1 can also be referred to as a lower center electrode 4-1, and the first edge electrode 4-2 can also be referred to as a lower edge electrode 4-2. The first intermediate electrode 4-1 refers to the electrode located at the center position and connected to the first intermediate electrode 4-1 pad 3-3. The first edge electrode 4-2 refers to the electrode surrounding the first intermediate electrode 4-1 and connected to the first edge electrode 4-2 pad 3-4. The second electrode layer 6 includes a second intermediate electrode 6-1 and a second edge electrode 6-2. In Figure 1 In the illustrated perspective, the second electrode layer 6 can also be referred to as an upper electrode layer 6, the second intermediate electrode 6-1 can also be referred to as an upper center electrode 6-1, and the second edge electrode 6-2 can also be referred to as an upper edge electrode 6-2. The second intermediate electrode 6-1 refers to the electrode located at the center position and connected to the second intermediate electrode 6-1 pad 3-5. The second edge electrode 6-2 refers to the electrode surrounding the second intermediate electrode 6-1 and connected to the second edge electrode 6-2 pad 3-6.

[0041] In the embodiment of the present application, in the resonance mode, the pressure sensor is sensitive to static vacuum pressure. At this time, the diaphragm 3 oscillates outward, and its vibration damping is proportional to the vacuum pressure of the external environment: the greater the pressure, the greater the damping, resulting in a decrease in the vibration displacement of the diaphragm 3. Through the piezoelectric layer 5, the vibration displacement of the diaphragm 3 can be detected, thereby realizing the measurement of the vacuum pressure. In addition, the first electrode layer 4 and the second electrode layer 6 can actuate the diaphragm 3. The user can control the range of the sensor by adjusting the thickness and size of the diaphragm 3 and the depth of the reference pressure cavity. In the dynamic pressure mode, the pressure sensor is sensitive to dynamic pressure. In this state, the diaphragm 3 does not actively generate vibration, but only deforms under the action of the external dynamic pressure to be measured and transmits this deformation to the piezoelectric layer 5. Through the piezoelectric effect, the sensor can generate a signal matching the amplitude of the high-frequency dynamic pressure, thereby realizing the sensitive detection of the dynamic pressure. In the dynamic pressure mode, it is required that the deformation stiffness of the diaphragm 3 be as large as possible. In addition, the relevant parameters of the diaphragm 3 can be determined according to the required dynamic pressure frequency range.

[0042] The technical solution of the embodiment of the present invention addresses the contradiction of existing sensors that cannot simultaneously measure dynamic pressure and vacuum pressure, and designs a structural design for a pressure sensor. Specifically, the pressure sensor includes a stacked substrate 1, a dielectric layer 2, a vibrating membrane 3, a first electrode layer 4, a piezoelectric layer 5, and a second electrode layer 6. A pressure reference cavity 1-1 is provided on the top of the substrate 1; a first ground pad 3-1, a second ground pad 3-2, a first edge electrode pad 3-4, a first intermediate electrode pad 3-3, a second edge electrode pad 3-6, and a second intermediate electrode pad 3-5 are provided on the vibrating membrane 3; the first electrode layer 4 includes a first intermediate electrode 4-1 and a first edge electrode 4-2 surrounding the first intermediate electrode 4-1; the piezoelectric layer 5 includes an intermediate piezoelectric film 5-1 and an edge piezoelectric film 5-2 surrounding the intermediate piezoelectric film 5-1; and the second electrode layer 6 includes a second intermediate electrode 6-1 and a second edge electrode 6-2 surrounding the second intermediate electrode 6-1. The embodiments of the present invention can operate in two modes: a resonant mode and a dynamic pressure mode, depending on the pressure signal control method. The resonant mode measures vacuum pressure, while the dynamic pressure mode measures dynamic pressure. Therefore, the pressure sensor provided by the embodiments of the present invention integrates the measurement of dynamic pressure and static vacuum pressure using a single sensitive structure, thus achieving fusion measurement of both pressures with a single sensitive structure.

[0043] On the basis of the above embodiments, continue to refer to Figure 1 Optionally, in the resonance mode, the thickness and size of the vibration membrane 3 and the depth of the pressure reference cavity 1-1 are adjusted to control the range of the pressure sensor.

[0044] In an embodiment of the present invention, in the dynamic pressure mode, increasing the thickness of the vibration membrane 3 and reducing its diameter and area will increase its stiffness, resulting in an increase in its intrinsic resonant frequency, thereby improving the response speed to dynamic pressure, that is, it is suitable for the measurement of high-frequency dynamic pressure. In the resonance mode, changing the depth of the pressure reference cavity 1-1, the area and thickness of the vibration membrane 3 will affect the damping characteristics of the vibration membrane 3 at resonance. When the depth of the pressure reference cavity 1-1 is reduced, the vibration membrane 3 is more susceptible to damping under the same pressure to be measured. The pressure is characterized by measuring the change in the peak-to-peak value of the vibration amplitude of the vibration membrane 3, thereby achieving the measurement of vacuum pressure. In summary, by adjusting the thickness, size and depth of the pressure reference cavity 1-1 of the vibration membrane 3, the stiffness and damping characteristics of the vibration membrane 3 can be optimized, and the measurement range of the pressure sensor can be controlled to adapt to different application requirements.

[0045] Based on the above embodiments, Figures 1-4 Optionally, in the resonance mode, the first middle electrode 4 - 1 and the second middle electrode 6 - 1 are actuating electrodes, and the first edge electrode 4 - 2 and the second edge electrode 6 - 2 are detecting electrodes.

[0046] Specifically, under the control of the control circuit, the actuating electrodes drive the vibration of the diaphragm 3 by applying voltage, while the detecting electrodes are responsible for capturing the electrical signal generated by the displacement of the diaphragm 3. The synergistic effect of the actuating and detecting electrodes enables the pressure sensor to effectively measure pressure in resonant mode.

[0047] On the basis of the above embodiments, continue to refer to Figure 1 Optionally, the shape of the pressure reference chamber 1-1 is circular, polygonal or a combination thereof.

[0048] Based on the above embodiments, optionally, the pressure of the pressure reference chamber 1 - 1 is less than the set pressure.

[0049] Specifically, the set pressure refers to the lower limit of the pressure measurement range of the sensor in both modes during design or calibration. The set pressure is typically preset to ensure that the pressure sensor can operate normally within its intended operating range. For example, the set pressure may be 10 Pa.

[0050] The technical solution of the embodiment of the present invention, by setting the shape and pressure of the pressure reference cavity 1-1, not only improves the sensitivity and measurement accuracy of the pressure sensor, but also enhances its adaptability and stability, so that the pressure sensor can still maintain good performance under different working conditions.

[0051] On the basis of the above embodiments, continue to refer to Figure 1 Optionally, the vibration membrane 3 is bonded to the dielectric layer 2 ; the dielectric layer 2 and the substrate 1 are bonded and hermetically sealed; the vibration membrane 3 should ensure good insulation from the first electrode layer 4 .

[0052] In the embodiments of the present invention, the hermetic package effectively prevents gas leakage, ensuring that the pressure sensor maintains a stable internal pressure environment during measurement, thereby improving measurement accuracy. Furthermore, the hermetic package prevents external contaminants such as dust and moisture from entering the pressure sensor, protecting sensitive components and extending the service life of the pressure sensor. The close fit between the diaphragm 3 and the dielectric layer 2 ensures that the mechanical displacement generated by the diaphragm 3 is effectively transmitted to the dielectric layer 2, thereby improving the sensitivity of the sensor.

[0053] Based on the above embodiments, Figure 1-Figure 5 Optionally, the gap between the first intermediate electrode 4-1 and the first edge electrode 4-2 is greater than the first set distance; optionally, the gap between the first intermediate electrode 4-4 and the second edge electrode 6-2 is greater than the first set distance; optionally, the gap between the intermediate piezoelectric film 5-1 and the edge piezoelectric film 5-2 is greater than the second set distance; wherein the second set distance is smaller than the first set distance.

[0054] Specifically, in an embodiment of the present invention, the gap between the first intermediate electrode 4-1 and the first edge electrode 4-2 is set to be greater than the first set distance, so as to ensure reliable insulation between the electrodes and avoid mutual interference of signals. Exemplarily, the first set distance can be 10 microns. Similarly, in an embodiment of the present invention, the gap between the second intermediate electrode 6-1 and the second edge electrode 6-2 is set to be greater than the first set distance, so as to ensure reliable insulation between the electrodes and avoid mutual interference of signals. In an embodiment of the present invention, the gap between the intermediate piezoelectric film 5-1 and the edge piezoelectric film 5-2 is set to be greater than the second set distance, so as to ensure reliable insulation between the piezoelectric films and avoid mutual interference of signals. Exemplarily, the second set distance can be 5 microns.

[0055] In this embodiment of the present invention, the middle piezoelectric film 5-1 corresponds to the second middle electrode 6-1 and the first middle electrode 4-1, and the edge piezoelectric film 5-2 corresponds to the second edge electrode 6-2 and the first edge electrode 4-2. The dimensions of each electrode (6-1, 6-2, 4-1, 4-2) are slightly smaller than the corresponding piezoelectric film to prevent short circuits between the first electrode layer 4, the piezoelectric layer 3, and the second electrode layer 6.

[0056] Based on the above embodiments, Figure 1-Figure 5 Optionally, the material of the first intermediate electrode 4-1 and the first edge electrode 4-2 is at least one of copper, aluminum or gold; optionally, the material of the second intermediate electrode 6-1 and the second edge electrode 6-2 is at least one of copper, aluminum or gold; optionally, the material of the intermediate piezoelectric film 5-1 is at least one of aluminum nitride, scandium aluminum nitride or zinc oxide; the material of the edge piezoelectric film 5-2 is at least one of aluminum nitride, scandium aluminum nitride or zinc oxide; wherein the material of the intermediate piezoelectric film 5-1 and the material of the edge piezoelectric film 5-2 are the same or different.

[0057] In embodiments of the present invention, the electrodes are made of highly conductive materials such as copper, aluminum, or gold, ensuring efficient current conduction and reducing signal loss. The piezoelectric film is made of materials such as aluminum nitride, scandium aluminum nitride, or zinc oxide, enabling efficient conversion of mechanical energy into electrical energy when pressure is applied, thereby improving the sensor's signal output. The pressure sensor allows the middle piezoelectric film 5-1 and the edge piezoelectric film 5-2 to be made of the same or different materials. This design flexibility allows for optimization for specific applications or performance requirements.

[0058] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present invention can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved. This is not limited herein.

[0059] The above detailed description does not limit the scope of the application. Various modifications, combinations, sub-combinations and alternatives can be made to the detailed description. Any modification, equivalent replacement and improvement etc. made within the spirit and principle of the application shall be included in the scope of the application.

Claims

1. A pressure sensor, characterized in that: Its working modes include resonance mode and dynamic pressure mode; the pressure sensor includes: A substrate, wherein a pressure reference cavity is provided on the top of the substrate; a dielectric layer, located on the substrate and sealing the pressure reference cavity; a vibrating membrane located on a side of the dielectric layer away from the substrate; the vibrating membrane oscillates out of the plane in the resonance mode and does not actively vibrate in the dynamic pressure mode; the vibrating membrane is provided with a first ground pad, a second ground pad, a first edge electrode pad, a first middle electrode pad, a second edge electrode pad, and a second middle electrode pad; wherein the first ground pad and the second ground pad are grounded; a first electrode layer located on a side of the vibrating membrane away from the substrate; the first electrode layer comprising a first middle electrode and a first edge electrode surrounding the first middle electrode, the first middle electrode being connected to the first middle electrode pad, and the first edge electrode being connected to the first edge electrode pad; a piezoelectric layer located on a side of the first electrode layer away from the substrate; the piezoelectric layer comprising an intermediate piezoelectric film and an edge piezoelectric film surrounding the intermediate piezoelectric film; the piezoelectric layer detecting the vibration displacement of the vibrating membrane in the resonant mode to measure vacuum pressure, and detecting the dynamic deformation in the dynamic pressure mode to measure dynamic pressure; a second electrode layer located on a side of the piezoelectric layer away from the substrate; the second electrode layer includes a second middle electrode and a second edge electrode surrounding the second middle electrode, the second middle electrode is connected to the second middle electrode pad, and the second edge electrode is connected to the second edge electrode pad; wherein, in the resonance mode, the thickness and size of the vibration membrane and the depth of the pressure reference cavity are adjusted to control the range of the pressure sensor; In the resonance mode, the first middle electrode and the second middle electrode are actuation electrodes, and the first edge electrode and the second edge electrode are detection electrodes. The vibration membrane is attached to the dielectric layer; the dielectric layer and the substrate layer are attached and hermetically sealed; and the vibration membrane is insulated from the first electrode layer.

2. The pressure sensor according to claim 1, wherein The material of the intermediate piezoelectric film is at least one of aluminum nitride, scandium aluminum nitride or zinc oxide; the material of the edge piezoelectric film is at least one of aluminum nitride, scandium aluminum nitride or zinc oxide; wherein the material of the intermediate piezoelectric film is the same as or different from the material of the edge piezoelectric film.

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