Piezoelectric Resonant Pressure Sensor, Compensation System and Preparation Method

Abstract

The present application provides a piezoelectric resonant pressure sensor, a compensation system and a manufacturing method, relating to the technical field of manufacturing of sensitive components and sensors in the core electronics industry. The piezoelectric resonant pressure sensor includes a piezoelectric component, a resonant component and a pressure-sensitive component. The piezoelectric component is directly or indirectly connected to an external circuit. The resonant component is disposed on one side of the piezoelectric component, and a resonant cavity is formed on the side of the resonant component facing away from the piezoelectric component. The pressure-sensitive component is connected to the side of the resonant component facing away from the piezoelectric component, and a pressure cavity is formed on the side of the pressure-sensitive component facing away from the resonant component. The pressure cavity is used to receive the pressure to be detected. A pressure-sensitive thin film is formed at the position where the pressure-sensitive component forms the pressure cavity, and at least part of the pressure-sensitive thin film closes the resonant cavity. According to the piezoelectric resonant pressure sensor provided by the examples of the present application, the pressure measurement range of the piezoelectric resonant pressure sensor can be expanded, and thus the application range of the piezoelectric resonant pressure sensor can be expanded.

Description

Technical Field

[0001] This application relates to the technical field of manufacturing sensitive components and sensors in the electronic core industry, and particularly relates to a piezoelectric resonant pressure sensor, a compensation system, and a preparation method. Background Art

[0002] A pressure sensor can convert the received pressure signal into an electrical signal according to a certain rule and output the electrical signal to other devices, and belongs to a sensitive component. Pressure sensors are widely used in technical fields such as national defense, automobiles, petroleum, aerospace, and intelligent hardware, and belong to the technical field of the electronic core industry.

[0003] With the development of micro-electro-mechanical system (MEMS) technology, a pressure sensor can be combined with MEMS technology to achieve mass production of the pressure sensor and improve the production efficiency of the pressure sensor.

[0004] According to different working principles, pressure sensors can be divided into piezoelectric resonant pressure sensors, piezoresistive pressure sensors, capacitive pressure sensors, piezoelectric pressure sensors, etc. Among them, due to the advantages of good stability and high precision of piezoelectric resonant pressure sensors, they are widely used in fields with high precision requirements and harsh environments, such as aerospace and petroleum.

[0005] Based on the structure of the existing piezoelectric resonant pressure sensor, the pressure detection range of the piezoelectric resonant pressure sensor is small, which may affect the applicable range of the piezoelectric resonant pressure sensor. Summary of the Invention

[0006] This application provides a piezoelectric resonant pressure sensor to expand the pressure detection range of the piezoelectric resonant pressure sensor and expand the applicable range of the piezoelectric resonant pressure sensor.

[0007] In a first aspect, an example of this application provides a piezoelectric resonant pressure sensor applied to the electronic core industry. The piezoelectric resonant pressure sensor includes a piezoelectric component, a resonant component, and a pressure-sensitive component. The piezoelectric component is directly or indirectly connected to an external circuit. The resonant component is disposed on one side of the piezoelectric component, and a resonant cavity is formed on the side of the resonant component facing away from the piezoelectric component. The pressure-sensitive component is connected to the side of the resonant component facing away from the piezoelectric component, and a pressure cavity is formed on the side of the pressure-sensitive component facing away from the resonant component. The pressure cavity is used to receive the pressure to be detected. The position where the pressure-sensitive component forms the pressure cavity forms a pressure-sensitive film, and at least part of the pressure-sensitive film closes the resonant cavity.

[0008] According to the piezoelectric resonant pressure sensor provided in the example of this application, the pressure chamber can receive the pressure to be detected, and the pressure to be detected can be transmitted to the piezoelectric component and the resonant component through the pressure sensitive component, and the pressure to be detected is detected by the characteristics of the piezoelectric component. Since the piezoelectric component is arranged on the side of the resonant component away from the pressure sensitive component, the piezoelectric component is separated from the pressure chamber that receives the pressure to be detected. And since a resonant cavity is arranged on the resonant component. In the case where the piezoelectric component drives the resonant component to vibrate, the resonant cavity can provide a deformation space for the piezoelectric component, reducing the possibility of the piezoelectric component being damaged due to a large deformation amount caused by vibration.

[0009] When the possibility of damage to the piezoelectric component is reduced, the piezoelectric resonant pressure sensor provided in the example of the present application can withstand a larger pressure to be detected, thereby improving the pressure measurement range of the piezoelectric resonant pressure sensor, expanding the measurement range of the piezoelectric resonant pressure sensor, and expanding the application scope of the piezoelectric resonant pressure sensor, so that the piezoelectric resonant pressure sensor can be widely used in the core technology field of the electronics industry.

[0010] In addition, in the example of the present application, since the pressure sensitive component forms a pressure sensitive film at the position where the pressure cavity is opened, and at least part of the pressure sensitive film closes the resonant cavity, the resonant cavity and the pressure cavity at least partially overlap. Based on this, the volume of the resonant piezoelectric sensor can be reduced, which is conducive to the miniaturization of the piezoelectric resonant pressure sensor and the integrated development of the piezoelectric resonant pressure sensor.

[0011] In some possible implementations, a pressure cavity is provided at a position where the pressure sensitive component closes the resonance cavity.

[0012] Since the pressure sensitive film is formed at the position where the pressure sensitive component opens the pressure cavity, and at least part of the pressure sensitive film closes the resonant cavity, it can be known that the projection of the resonant cavity coincides with the projection of the pressure cavity along the direction from the resonant cavity to the pressure cavity. In addition, since the pressure cavity is provided at the position where the pressure sensitive component closes the resonant cavity, it can be known that the projection of the resonant cavity can completely fall within the projection range of the pressure cavity along the direction from the resonant cavity to the pressure cavity, which can further reduce the volume of the piezoelectric resonant pressure sensor and is conducive to the miniaturization of the piezoelectric resonant pressure sensor.

[0013] In some possible implementations, the pressure sensitive component further includes a resonant substrate, the pressure sensitive film cooperates with the resonant substrate to form a pressure cavity, and the resonant substrate is located on a side of the pressure sensitive film away from the resonant component.

[0014] By setting up a resonant substrate, which cooperates with a pressure-sensitive film to form a pressure chamber, an operator can control a fluid such as gas or liquid to apply pressure to the chamber wall of the pressure chamber. By setting up the pressure chamber, the force on the pressure-sensitive film can be made more concentrated, facilitating the operator to apply the pressure to be detected to the chamber wall of the pressure chamber.

[0015] In some possible implementation manners, a pressure chamber is provided at the position where the pressure-sensitive component closes the resonant cavity. The resonant component includes a connecting structure and a resonant film connected to each other. The connecting structure and the resonant film cooperate to form a resonant cavity, and the resonant film is located on the side of the connecting structure away from the pressure-sensitive component.

[0016] Since a pressure-sensitive film is provided on one side of the connecting structure and a piezoelectric component is provided on the other side of the connecting structure. Based on this, the pressure to be detected acting on the pressure-sensitive film can be transmitted to the piezoelectric component through the connecting structure, converted into stress on the piezoelectric component and the resonant component, and then the structural resonant frequency changes. Since the resonant cavity is provided on one side of the piezoelectric component, the resonant cavity can provide a vibration space for the vibration of the piezoelectric component, reducing the possibility of damage to the piezoelectric component due to vibration deformation.

[0017] The connecting structure can connect the pressure-sensitive film and the piezoelectric component, and the connecting structure can change the acting direction of the pressure to be detected, making the pressure to be detected acting perpendicularly on the piezoelectric component smaller, further reducing the possibility of damage to the piezoelectric component, improving the pressure-bearing capacity of the resonant film, further expanding the detection range of the piezoelectric resonant pressure sensor, and ensuring the linearity of the piezoelectric resonant pressure sensor within the pressure detection range.

[0018] In some possible implementation manners, the side of the connecting structure close to the pressure-sensitive component is an anchor point. The distance between the anchor point and the resonant film is a first distance, and the distance between the anchor point and the pressure-sensitive component is a second distance, and the first distance is greater than the second distance.

[0019] By setting the first distance to be greater than the second distance, the resonant film, the pressure-sensitive component and the anchor point can act together to form a lever, the first distance is the first lever arm, and the second distance is the second lever arm. Based on the lever principle, the connecting structure with an anchor point can amplify the working stress generated by the pressure to be detected, thereby improving the detection sensitivity of the piezoelectric resonant pressure sensor.

[0020] In some possible implementation manners, the piezoelectric component includes a first lead electrode, a second lead electrode, a first electrode, a piezoelectric layer and a second electrode. Among them, the second electrode is provided on the side of the resonant component away from the pressure-sensitive component, and the side of the second electrode facing the resonant component is directly or indirectly connected to the resonant component.

[0021] The piezoelectric layer is disposed on the side of the second electrode away from the resonant component, and the side of the piezoelectric layer facing the second electrode is connected to the second electrode.

[0022] The first electrode is disposed on the side of the piezoelectric layer away from the second electrode, and the side of the piezoelectric layer facing the first electrode is connected to the first electrode.

[0023] The first lead electrode is disposed on the side of the first electrode away from the piezoelectric layer. One end of the first lead electrode is connected to the first electrode, and the other end of the first lead electrode is connected to the first part of the external circuit. The second lead electrode is disposed on the side of the second electrode facing the piezoelectric layer. One end of the second lead electrode is connected to the second electrode, and the other end of the second lead electrode is connected to the second part of the external circuit.

[0024] Compared with the resistance detection type piezoelectric sensor which needs to set up a Wheatstone bridge and the capacitance detection type pressure sensor which needs to set up a capacitance bridge, the piezoelectric resonant pressure sensor provided by the example of the present application does not need to set up an additional detection circuit, has a simpler structure and lower manufacturing cost.

[0025] In some possible implementation manners, the piezoelectric resonant pressure sensor is provided with at least one groove, and the groove is disposed between the resonant thin film and the pressure sensitive thin film. Alternatively, the groove is disposed on the side of the resonant component away from the resonant substrate, and the notch of the groove is opened away from the resonant substrate.

[0026] The groove can keep a distance between the resonant substrate and the connecting structure, thereby reducing the cross-sectional area of the connecting structure, making the working stress transmitted to the pressure sensitive thin film through the connecting structure more concentrated, which is beneficial to improving the detection accuracy of the piezoelectric resonant pressure sensor.

[0027] In some possible implementation manners, the piezoelectric resonant pressure sensor further includes a cover, and the cover is disposed on the side of the piezoelectric component away from the pressure sensitive component, and the cover is directly or indirectly connected to the piezoelectric component.

[0028] In a vacuum environment, the cover can be used to encapsulate the piezoelectric resonator, and the piezoelectric resonator can include a resonant component and a piezoelectric component. The cover can be disposed on the side of the piezoelectric component away from the resonant component to isolate the piezoelectric component from the atmospheric environment, ensure that the piezoelectric component works in a vacuum environment, thereby increasing the value corresponding to the quality factor of the piezoelectric resonant pressure sensor and ensuring the working performance of the piezoelectric resonant pressure sensor.

[0029] The second aspect of the present application provides a compensation system, which includes a driving component, a detecting component integrated together, and the piezoelectric resonant pressure sensor mentioned in any of the above examples. At least two piezoelectric resonant pressure sensors include at least one pressure-receiving sensor and at least one compensation sensor.

[0030] According to the compensation system provided by the examples of the present application, when the detection component detects the resonant frequencies of the pressure sensor and the compensation sensor, as long as the resonant frequency output by the pressure sensor is subtracted from the resonant frequency output by the compensation sensor, and then the final resonant frequency is extracted, the influence of environmental factors can be excluded, and the detection accuracy of the compensation system for the pressure to be detected can be improved.

[0031] The third aspect of the present application provides a method for manufacturing a piezoelectric resonant pressure sensor, which is applicable to the piezoelectric resonant pressure sensor mentioned in any of the above examples. The method is used to process a piezoelectric resonant pressure sensor from a first SOI wafer and a second SOI wafer. The first SOI wafer includes a first device layer, a first buried oxide layer, and a first substrate layer. The second SOI wafer includes a second device layer, a second buried oxide layer, and a second substrate layer.

[0032] The thickness of the first device layer is equal to the sum of the height of the resonant cavity and the thickness of the resonant film. The thickness of the second device layer is equal to the thickness of the pressure-sensitive film.

[0033] The method includes: taking the first SOI wafer and processing a resonant cavity on the first device layer. Taking the second SOI wafer, bonding the second device layer to the first device layer, and the second device layer seals the resonant cavity. Wherein, an oxide layer is formed between the second device layer and the first device layer during the bonding process. Removing the first buried oxide layer and the first substrate layer, and part of the first device layer serves as the resonant film. Arranging a piezoelectric component on the side of the first device layer facing away from the second SOI wafer. Opening a pressure cavity on the second substrate layer and forming a pressure-sensitive film, wherein at least part of the pressure-sensitive film closes the resonant cavity. Description of the Drawings

[0034] Figure 1 It is a schematic structural diagram of a piezoelectric resonant pressure sensor provided by the examples of the present application.

[0035] Figure 2 It is a top view of a piezoelectric resonant pressure sensor provided by the examples of the present application.

[0036] Figure 3 is Figure 2 The cross-sectional view taken along A-A in

[0037] Figure 4 is Figure 2 The cross-sectional view taken along B-B in

[0038] Figure 5 It is a schematic structural diagram of another piezoelectric resonant pressure sensor provided by the examples of the present application.

[0039] Figure 6 It is a top view of another piezoelectric resonant pressure sensor provided by the examples of the present application.

[0040] Figure 7 is Figure 6 a C-C cross-sectional view.

[0041] Figure 8 Schematic diagram of the working principle of a piezoelectric resonant pressure sensor provided by an example of the present application.

[0042] Figure 9 Schematic diagram of the resonance principle of a piezoelectric resonant pressure sensor provided by an example of the present application.

[0043] Figure 10 Schematic diagram of the internal structure of a piezoelectric resonant pressure sensor provided by an example of the present application.

[0044] Figure 11 Schematic diagram of the structure of a piezoelectric resonant pressure sensor without lead electrodes and a protective layer provided by an example of the present application, and this structure is provided with 4 lead bridges.

[0045] Figure 12 Schematic diagram of the structure of a piezoelectric resonant pressure sensor without lead electrodes and a protective layer provided by an example of the present application, and this structure is provided with 3 lead bridges.

[0046] Figure 13 Schematic diagram of the structure of a piezoelectric resonant pressure sensor without lead electrodes and a protective layer provided by an example of the present application, and this structure is provided with 2 lead bridges.

[0047] Figure 14 Schematic diagram of the structure of a piezoelectric resonant pressure sensor without lead electrodes and a protective layer provided by an example of the present application, and this structure is provided with 1 lead bridge.

[0048] Figure 15 Schematic diagram of the structure of a piezoelectric resonant pressure sensor without lead electrodes and a protective layer provided by an example of the present application, and this structure is not provided with a lead bridge.

[0049] Figure 16 Schematic diagram of the structure of another piezoelectric resonant pressure sensor provided by an example of the present application.

[0050] Figure 17 Schematic diagram of the process flow of a method for manufacturing a piezoelectric resonant pressure sensor provided by an example of the present application.

[0051] Figure 18 Schematic diagram of the structure of a first SOI wafer before processing provided by an example of the present application.

[0052] Figure 19 Schematic diagram of the structure of a first SOI wafer processed with a resonant cavity and trenches provided by an example of the present application.

[0053] Figure 20 Schematic diagram of a structure after flipping a first SOI wafer processed with a resonator and trenches provided by an example of this application.

[0054] Figure 21 Schematic diagram of a structure of a second SOI wafer before processing provided by an example of this application.

[0055] Figure 22 Schematic diagram of a structure of bonding and connecting a first SOI wafer and a second SOI wafer provided by an example of this application.

[0056] Figure 23 Schematic diagram of a structure of bonding and connecting a first SOI wafer and a second SOI wafer and removing the first substrate layer and the first buried oxide layer provided by an example of this application.

[0057] Figure 24 Schematic diagram of a structure of depositing a piezoelectric component on the side of the first device layer facing away from the second SOI wafer provided by an example of this application.

[0058] Figure 25 Provided by an example of this application is a structure based on Figure 24 Schematic diagram of the structure after processing the piezoelectric component.

[0059] Figure 26 Provided by an example of this application is a structure based on Figure 25 Schematic diagram of a structure of setting a protective layer on the side of the piezoelectric component facing away from the first device layer.

[0060] Figure 27 Provided by an example of this application is a structure based on Figure 26 Schematic diagram of a structure of processing a first connection hole from the protective layer.

[0061] Figure 28 Provided by an example of this application is a structure based on Figure 27 Schematic diagram of a structure of processing a second connection hole from the protective layer.

[0062] Figure 29 Provided by an example of this application is a structure based on Figure 28 Schematic diagram of a structure of depositing a lead electrode layer on the side of the protective layer facing away from the first device layer.

[0063] Figure 30 Provided by an example of this application is a structure based on Figure 29 Schematic diagram of a structure of processing the lead electrode layer.

[0064] Figure 31 Provided by an example of this application is a structure based on Figure 30 Schematic diagram of a structure of processing a pressure cavity on the side of the second SOI wafer facing away from the first device layer.

[0065] Figure 32A structure provided for an example of the present application based on Figure 31 Schematic structural diagram of processing a groove from a protective layer.

[0066] Figure 33 Schematic structural diagram of a glass wafer provided for an example of the present application.

[0067] Figure 34 Schematic structural diagram of processing a cavity on a glass wafer to form a cap provided for an example of the present application.

[0068] Figure 35 Schematic structural diagram of a glass wafer connected to the side of the protective layer away from the piezoelectric layer provided for an example of the present application.

[0069] Figure 36 Schematic structural diagram of a compensation system provided for an example of the present application.

[0070] Figure 37 Schematic working process diagram of a compensation system provided for an example of the present application.

[0071] Explanation of reference numerals:

[0072] 100, piezoelectric resonant pressure sensor; 110, piezoelectric component; 111, first lead electrode; 1111, first connection hole; 112, second lead electrode; 1121, second connection hole; 113, first electrode; 114, piezoelectric layer; 115, second electrode; 120, resonant component; 121, resonant cavity; 122, resonant thin film; 123, connection structure; 124, resonant substrate; 130, pressure-sensitive component; 131, pressure cavity; 132, pressure-sensitive thin film; 133, resonant substrate; 140, protective layer; 150, oxide layer; 160, cap; 170, groove; 171, lead bridge; 172, beam structure; 200, compensation system; 210, pressure-receiving sensor; 220, compensation sensor; 230, driving component; 240, detecting component; 310, first device layer; 320, first buried oxide layer; 330, first substrate layer; 410, second device layer; 420, second buried oxide layer; 430, second substrate layer; 500, glass wafer. Detailed implementation manners

[0073] To make the objectives, technical solutions and advantages of the examples of the present application clearer, the technical solutions in the examples of the present application will be clearly and completely described below with reference to the accompanying drawings in the examples of the present application. Obviously, the described examples are some but not all of the examples of the present application. All other examples obtained by those of ordinary skill in the art based on the examples in the present application without creative efforts shall fall within the scope of protection of the present application.

[0074] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the technical field to which this application belongs; the terms used in the description of this application are only for the purpose of describing specific examples and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the description, claims and drawings of this application are intended to cover non-exclusive inclusion.

[0075] Reference to "example" in this context means that a particular feature, structure, or characteristic described in connection with the example can be included in at least one example of this application. The phrase "example" appearing in various places in the specification does not necessarily refer to the same example, nor is it an independent or alternative example mutually exclusive with other examples. It is explicitly and implicitly understood by those skilled in the art that the examples described herein can be combined with other examples.

[0076] The term "and / or" herein is merely a description of the relationship between associated objects, indicating that there can be three relationships. For example, A and / or B can represent: the existence of A, the simultaneous existence of A and B, and the existence of B. Additionally, the character " / " herein generally represents an "or" relationship between the associated objects before and after.

[0077] The directional terms appearing in the following description are all the directions shown in the figures and do not limit the specific structure of the piezoelectric resonant pressure sensor of this application.

[0078] Furthermore, the terms "first", "second", etc. in the description, claims or the above-mentioned drawings of this application are used to distinguish different objects and are not used to describe a specific order, and may explicitly or implicitly include one or more of such features.

[0079] In the description of this application, unless otherwise specified, the meaning of "plurality" refers to two or more (including two). Similarly, "multiple groups" refers to two or more groups (including two groups).

[0080] In the description of this application, it should be noted that unless otherwise clearly specified and limited, the terms "mounted", "connected" and "coupled" should be understood in a broad sense. For example, "connected" or "coupled" in a mechanical structure can refer to a physical connection. For example, a physical connection can be a fixed connection, such as a fixed connection through a spacer, such as a fixed connection through screws, bolts or other spacers; a physical connection can also be a detachable connection, such as a snap connection or a snap-fit connection; a physical connection can also be an integral connection, such as a welded, bonded or integrally formed connection. For those of ordinary skill in the art, the specific meaning of the above terms in this application can be understood according to specific circumstances.

[0081] The resonant pressure sensor indirectly measures the pressure to be detected by measuring the change in the resonant frequency of the structure. It has the advantages of high precision and good stability, and is suitable for scenarios with high precision requirements and harsh environments, such as aerospace and oil and gas exploration. Existing resonant pressure sensors include electrostatic excitation-resistance detection type resonant pressure sensors, piezoelectric excitation-piezoelectric detection type resonant pressure sensors, electromagnetic drive-electromagnetic detection type resonant pressure sensors, light drive-light detection type resonant pressure sensors, and piezoelectric resonant pressure sensors made of quartz materials, etc. The measurement structure can be a detection circuit or other structures that can detect the pressure to be detected.

[0082] Among them, the processing technology of the electrostatic excitation-resistance detection type resonant pressure sensor is relatively simple. However, since piezoresistive detection requires the use of a Wheatstone bridge, the circuit structure of the electrostatic excitation-resistance detection type resonant pressure sensor is relatively complex, and the processing requirements for the piezoresistors are relatively high due to the consistency of the piezoresistors.

[0083] The piezoelectric excitation-resistance detection type resonant pressure sensor is similar to the electrostatic excitation-resistance detection type, and also has the problems of complex circuit structure and high consistency requirements for piezoresistors.

[0084] The electromagnetic drive-electromagnetic detection type resonant pressure sensor uses the fact that the resonator is subjected to a time-varying Lorentz force in the excitation electromagnetic field and undergoes periodic vibration, and then uses the inverse process of electromagnetic drive to detect the vibration. Due to the requirement for the electromagnetic field, this method requires additional peripheral equipment of the sensor to provide a magnetic field, and it is not easy to miniaturize the sensor.

[0085] Based on the above, the present application provides an example of a piezoelectric resonant pressure sensor, a compensation system and a preparation method.

[0086] The piezoelectric resonant pressure sensor mentioned in the example of the present application can be combined with MEMS technology to achieve mass production of the piezoelectric resonant pressure sensor and improve the production efficiency of the piezoelectric resonant pressure sensor.

[0087] The piezoelectric resonant pressure sensor mentioned in the example of the present application can output a corresponding electrical signal based on the received pressure to be detected and belongs to a sensitive element.

[0088] In order to enable those skilled in the art to better understand the solution of the present application, the piezoelectric resonant pressure sensor, compensation system and preparation method provided in the example of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0089] Exemplarily, Figure 1 is a schematic structural diagram of a piezoelectric resonant pressure sensor provided in the example of the present application, Figure 2A top view of a piezoelectric resonant pressure sensor provided for an example of the present application. Figure 3 is Figure 2 a cross-sectional view taken along line A-A in Figure 4 is Figure 2 a cross-sectional view taken along line B-B in , please refer to Figures 1 to 4 The piezoelectric resonant pressure sensor 100 may include a piezoelectric component 110, a resonant component 120, and a pressure-sensitive component 130.

[0090] The piezoelectric component 110 may be directly or indirectly connected to an external circuit. The resonant component 120 is disposed on one side of the piezoelectric component 110, and a resonant cavity 121 is formed on the side of the resonant component 120 facing away from the piezoelectric component 110. The pressure-sensitive component 130 is connected to the side of the resonant component 120 facing away from the piezoelectric component 110. A pressure cavity 131 is formed on the side of the pressure-sensitive component 130 facing away from the resonant component 120, and the pressure cavity 131 is used to receive the pressure to be detected. A pressure-sensitive film 132 is formed at the position where the pressure-sensitive component 130 forms the pressure cavity 131, and at least a part of the pressure-sensitive film 132 closes the resonant cavity 121.

[0091] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the pressure cavity 131 can receive the pressure to be detected. Since the pressure cavity 131 is disposed on the side of the pressure-sensitive component 130 facing away from the resonant component 120, and the pressure-sensitive component 130 is directly or indirectly connected to the resonant component 120, the pressure to be detected can be transmitted to the resonant component 120 through the pressure-sensitive component 130. Also, since the resonant component 120 is disposed on one side of the piezoelectric component 110 and the resonant component 120 is directly or indirectly connected to the piezoelectric component 110, the pressure to be detected indirectly acting on the resonant component 120 can be transmitted to the piezoelectric component 110.

[0092] Next, the structure of the piezoelectric resonant pressure sensor 100 will be introduced in detail.

[0093] The pressure-sensitive component 130 may only include a pressure-sensitive film, or the pressure-sensitive component 130 may also include a pressure-sensitive film and other structures connected to the pressure-sensitive film.

[0094] In the case where the pressure-sensitive component 130 only includes a pressure-sensitive film, the pressure cavity 131 may be the space where the pressure-sensitive film faces away from the resonant component 120. In the case where the pressure-sensitive component 130 includes a pressure-sensitive film and other structures connected to the pressure-sensitive film, the pressure cavity 131 may also be the space jointly formed by the pressure-sensitive film and other structures connected to the pressure-sensitive film. The present application example does not make specific limitations on this.

[0095] The pressure to be detected received by the pressure-sensitive component 130 can be the pressure directly or indirectly applied to the pressure-sensitive component 130 by a fluid, and the fluid can be a liquid, a gas, etc.

[0096] The resonant component 120 can be directly or indirectly connected to the side of the pressure-sensitive component 130 facing away from the pressure chamber 131. A piezoelectric component 110 is provided on the side of the resonant component 120 facing away from the pressure-sensitive component 130. The pressure to be detected acting on the pressure-sensitive component 130 can be transmitted to the piezoelectric component 110 and the resonant component 120 through the pressure-sensitive component 130, and the piezoelectric component 110 can detect the pressure to be detected.

[0097] The pressure chamber 131 can be opened on the side of the pressure-sensitive component 130 facing away from the resonant component 120, and a pressure-sensitive thin film 132 is formed at the position where the pressure chamber 131 is opened on the pressure-sensitive component 130. It can be understood that along the direction from the resonant component 120 to the pressure-sensitive component 130, at least part of the projection of the resonant cavity 121 falls within the projection range of the pressure chamber 131.

[0098] For example, the projection of the resonant cavity 121 can completely fall within the projection range of the pressure chamber 131. At this time, the geometric center of the projection of the resonant cavity 121 can overlap with the geometric center of the projection of the pressure chamber 131, or there can be a distance between the geometric center of the resonant cavity 121 and the geometric center of the pressure chamber 131.

[0099] For example, the projection of part of the resonant cavity 121 can fall within the projection range of the pressure chamber 131, that is to say, the projection of the resonant cavity 121 and the projection of the pressure chamber 131 partially overlap.

[0100] The shape of the pressure chamber 131 can be the same as the shape of the resonant cavity 121, or the shape of the pressure chamber 131 can be different from the shape of the resonant cavity 121. In this application example, only the pressure chamber 131 is described as an example. For example, the shape of the pressure chamber 131 can be cylindrical, the shape of the pressure chamber 131 can also be prismatic, or the shape of the pressure chamber 131 can also be an irregular shape.

[0101] There can be one pressure chamber 131, or multiple pressure chambers 131 can be arranged at intervals. There can also be only one resonant cavity 121, or multiple resonant cavities 121 can be provided. This application example does not limit this.

[0102] This application example does not specifically limit the positional relationship between the resonant cavity 121 and the pressure chamber 131, as long as at least part of the projection of the resonant cavity 121 coincides with the projection of the pressure chamber 131, so as to ensure that the pressure to be detected received by the pressure chamber 131 can be transmitted to the piezoelectric component 110 through the resonant cavity 121, and the piezoelectric component 110 can detect the pressure to be detected.

[0103] Exemplarily, the piezoelectric component 110 may include a piezoelectric layer 114 and an electrode. The piezoelectric layer 114 may be made of piezoelectric thin film materials such as AlN, ScAlN, PZT (piezoelectric ceramics), ZnO, and LiNbO3. Due to the piezoelectricity of the piezoelectric thin film material, when the piezoelectric layer 114 receives pressure, two opposite sides of the piezoelectric layer 114 can generate a potential difference. The positive piezoelectric effect and the reverse piezoelectric effect of the piezoelectric layer 114 are used to obtain the relevant parameters of the pressure to be detected. The relevant parameters may include the numerical value of the pressure to be detected and the direction parameters of the pressure to be detected, etc. The specific description can be found below.

[0104] The electrode can be directly electrically connected to an external circuit, or the electrode can be indirectly connected to an external circuit via a conductive member such as a wire.

[0105] The external circuit can be a circuit for detecting current or voltage. The example of this application does not limit the specific type of the external circuit, as long as the external circuit can detect the electrical signal output by the piezoelectric component 110.

[0106] Based on the above, according to the piezoelectric resonant pressure sensor 100 provided in the example of the present application, the pressure chamber 131 can receive the pressure to be detected, and the pressure to be detected can be transmitted to the piezoelectric component 110 and the resonant component 120 through the pressure sensitive component 130, and the pressure to be detected is detected through the characteristics of the piezoelectric component 110. Since the piezoelectric component 110 is arranged on the side of the resonant component 120 away from the pressure sensitive component 130, the piezoelectric component 110 is separated from the pressure chamber 131 that receives the pressure to be detected. And since the resonant component 120 is provided with a resonant cavity 121. In the case where the piezoelectric component 110 drives the resonant component 120 to vibrate, the resonant cavity 121 can provide a deformation space for the piezoelectric component 110, thereby reducing the possibility that the piezoelectric component 110 is damaged due to a large deformation amount caused by vibration.

[0107] When the possibility of damage to the piezoelectric component 110 is reduced, the piezoelectric resonant pressure sensor 100 provided in the example of the present application can withstand a larger pressure to be detected, thereby improving the pressure measurement range of the piezoelectric resonant pressure sensor 100, expanding the measurement range of the piezoelectric resonant pressure sensor 100, and expanding the application scope of the piezoelectric resonant pressure sensor 100, so that the piezoelectric resonant pressure sensor 100 can be widely used in the core technology field of the electronics industry.

[0108] In addition, in the example of this application, since the pressure-sensitive film 132 is formed at the position where the pressure-sensitive component 130 opens the pressure chamber 131, and at least part of the pressure-sensitive film 132 closes the resonant cavity 121, the resonant cavity 121 and the pressure chamber 131 at least partially overlap. Based on this, the volume of the resonant piezoelectric sensing can be reduced, which is beneficial to the miniaturization of the piezoelectric resonant pressure sensor 100 and the integrated development of the piezoelectric resonant pressure sensor 100.

[0109] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, please refer to Figure 3 , a pressure chamber 131 is provided at the position where the pressure-sensitive component 130 closes the resonant cavity 121.

[0110] Since the pressure-sensitive film 132 is formed at the position where the pressure-sensitive component 130 opens the pressure chamber 131, and at least part of the pressure-sensitive film 132 closes the resonant cavity 121, it can be known that along the direction from the resonant cavity 121 to the pressure chamber 131, the projection of the resonant cavity 121 coincides with the projection of the pressure chamber. Also, since a pressure chamber 131 is provided at the position where the pressure-sensitive component 130 closes the resonant cavity 121, based on this, it can be known that along the direction from the resonant cavity 121 to the pressure chamber 131, the projection of the resonant cavity 121 can completely fall within the projection range of the pressure chamber 131, which can further reduce the volume of the piezoelectric resonant pressure sensor 100, is beneficial to the miniaturization of the piezoelectric resonant pressure sensor 100, and is beneficial to the integrated development of the piezoelectric resonant pressure sensor 100.

[0111] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the pressure-sensitive component 130 may further include a resonant substrate 133. The pressure-sensitive film 132 and the resonant substrate 133 can cooperate to form the pressure chamber 131, and the resonant substrate 133 is located on the side of the pressure-sensitive film 132 away from the resonant component 120.

[0112] The resonant substrate 133 and the pressure-sensitive film 132 may be an integral structure. In this case, the pressure chamber 131 may be a cavity formed by removing the middle part of a block structure. The pressure-sensitive film 132 may be the corresponding part of the block structure at the bottom of the pressure chamber 131. The resonant substrate 133 may be the corresponding part of the block structure at the side wall of the pressure chamber 131.

[0113] The resonant substrate 133 may also be connected to the pressure-sensitive film 132 by bonding or other means. At this time, there may be multiple resonant substrates 133, and different resonant substrates 133 can be connected to the side walls of the corresponding pressure-sensitive films 132. In this case, the pressure-sensitive film 132 can serve as the bottom wall of the pressure chamber 131, and the resonant substrate 133 can serve as the side wall of the pressure chamber 131. The pressure-sensitive film 132 and the resonant substrate 133 jointly enclose the pressure chamber 131.

[0114] By providing a resonant substrate 133, the resonant substrate 133 and the pressure-sensitive film 132 cooperate to form a pressure chamber 131. An operator can control a fluid such as a gas or a liquid to apply pressure to the chamber wall of the pressure chamber 131. By providing the pressure chamber 131, the force on the pressure-sensitive film 132 can be made more concentrated, facilitating the operator to apply a pressure to be detected to the chamber wall of the pressure chamber 131.

[0115] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, Figure 5 FIG. is a schematic structural diagram of another piezoelectric resonant pressure sensor provided in the example of the present application, Figure 6 FIG. is a top view of another piezoelectric resonant pressure sensor provided in the example of the present application, Figure 7 is Figure 6 the cross-sectional view taken along C-C in Figures 5 to 7 , the resonant assembly 120 may include a connection structure 123 and a resonant film 122 connected to each other. The connection structure 123 and the resonant film 122 cooperate to form a resonant cavity 121. The resonant film 122 is located on the side of the connection structure 123 away from the pressure-sensitive assembly 130.

[0116] The connection structure 123 may be cylindrical, prismatic, frustum-shaped or other shapes. At least one connection structure 123 may be provided, and two, three or even more connection structures 123 may also be provided.

[0117] The connection structure 123 and the resonant film 122 may be an integral structure. In this case, the resonant cavity 121 may be a cavity formed by removing an intermediate part from a block-shaped structure. The resonant film 122 may be the corresponding part of the block-shaped structure corresponding to the bottom of the resonant cavity 121. The connection structure 123 may be the corresponding part of the block-shaped structure corresponding to the side wall of the resonant cavity 121.

[0118] The connection structure 123 may also be connected to the resonant film 122 by bonding or other means. At this time, the connection structure 123 may include a plurality of connection structures 123, and different connection structures 123 can be connected to the side walls of the corresponding resonant films 122. In this case, the resonant film 122 may serve as the bottom wall of the resonant cavity 121, and the connection structure 123 may serve as the side wall of the resonant cavity 121. The resonant film 122 and the connection structure 123 jointly enclose the resonant cavity 121.

[0119] Since a pressure-sensitive film 132 is provided on one side of the connection structure 123, a piezoelectric component 110 is provided on the other side of the connection structure 123. Based on this, the pressure to be detected acting on the pressure-sensitive film 132 can be transmitted to the resonant film 122 and the piezoelectric component 110 through the connection structure 123, generating stress in the resonant film 122 and the piezoelectric component 110, and then causing a change in the vibration frequency of the resonant film 122 and the piezoelectric component 110. Since the resonant cavity 121 is provided on one side of the piezoelectric component 110, the resonant cavity 121 can provide a vibration space for the vibration of the piezoelectric component 110, reducing the possibility of damage to the piezoelectric component 110 caused by deformation due to vibration.

[0120] The connection structure 123 can directly or indirectly connect the resonant film 122 to one side of the pressure-sensitive film 132. Figure 8 The following is a schematic diagram of the working principle of a piezoelectric resonant pressure sensor provided by an example of this application. Please refer to Figure 8 , the connection structure 123 can change the acting direction of the pressure to be detected.

[0121] Exemplarily, the pressure to be detected acts on the pressure-sensitive film 132 in a direction perpendicular to the pressure-sensitive film 132. The pressure to be detected acting on the pressure-sensitive film 132 can be transmitted to the resonant film 122 through the connection structure 123, and the connection structure 123 can convert the pressure to be detected perpendicular to the pressure-sensitive film 132 into a working stress whose acting direction forms an angle with the acting direction of the pressure to be detected.

[0122] In summary, the resonant cavity 121 can provide a vibration space for the vibration of the piezoelectric component 110, reducing the possibility of damage to the piezoelectric component 110 caused by deformation due to vibration. The connection structure 123 can connect the pressure-sensitive film 132 and the piezoelectric component 110, and the connection structure 123 can change the acting direction of the pressure to be detected, so that the pressure to be detected acting perpendicularly on the piezoelectric component 110 is smaller, further reducing the possibility of damage to the piezoelectric component 110, improving the pressure-bearing capacity of the resonant film 122, expanding the detection range of the piezoelectric resonant pressure sensor 100, and ensuring the linearity of the piezoelectric resonant pressure sensor 100 within the pressure detection range.

[0123] For the resonant cavity 121 mentioned in the above example, the cavity can be kept vacuum, or the cavity can be filled with a medium.

[0124] Exemplarily, the piezoelectric resonant pressure sensor 100 can be an absolute pressure sensor. The absolute pressure sensor is used to measure the absolute pressure and can convert the absolute pressure of a gas or liquid into an equivalent electrical signal for output.

[0125] Exemplarily, the piezoelectric resonant pressure sensor 100 may be a relative pressure sensor. The relative pressure sensor measures based on the atmospheric pressure. Therefore, the measurement result of the relative pressure sensor is relative to the atmospheric pressure. Thus, the relative pressure sensor can be used to measure the difference in relative pressure.

[0126] The user can select a suitable absolute pressure sensor or relative pressure sensor according to requirements. In the examples of the present application, there is no limitation on whether the cavity of the piezoelectric resonant pressure sensor 100 is filled with a medium.

[0127] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, one side of the connection structure 123 close to the pressure-sensitive component 130 can be an anchor point. The distance between the anchor point and the resonant film 122 is the first distance, and the distance between the anchor point and the pressure-sensitive component 130 is the second distance. The first distance is greater than the second distance.

[0128] The anchor point is the main stress point of the connection structure 123.

[0129] By setting the first distance greater than the second distance, the resonant film 122, the pressure-sensitive component 130, and the anchor point can act together to form a lever. The first distance is the first lever arm, and the second distance is the second lever arm. Based on the lever principle, the connection structure 123 with an anchor point can amplify the working stress generated by the pressure to be detected, thereby improving the detection sensitivity of the piezoelectric resonant pressure sensor 100.

[0130] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, Figure 9 For the schematic diagram of the resonance principle of a piezoelectric resonant pressure sensor provided in the examples of the present application, please refer to Figures 1 to 5 and Figure 9 , the piezoelectric component 110 may include a first lead electrode 111, a second lead electrode 112, a first electrode 113, a piezoelectric layer 114, and a second electrode 115.

[0131] The second electrode 115 may be disposed on the side of the resonant component 120 away from the pressure-sensitive component 130. The side of the second electrode 115 facing the resonant component 120 may be directly or indirectly connected to the resonant component 120. The piezoelectric layer 114 may be disposed on the side of the second electrode 115 away from the resonant component 120. The side of the piezoelectric layer 114 facing the second electrode 115 may be connected to the second electrode 115. The first electrode 113 may be disposed on the side of the piezoelectric layer 114 away from the second electrode 115. The side of the piezoelectric layer 114 facing the first electrode 113 may be connected to the first electrode 113.

[0132] The first lead electrode 111 is disposed on the side of the first electrode 113 facing away from the piezoelectric layer 114. One end of the first lead electrode 111 can be connected to the first electrode 113, and the other end of the first lead electrode 111 can be connected to the first part of the external circuit.

[0133] The second lead electrode 112 is disposed on the side of the second electrode 115 facing the piezoelectric layer 114. One end of the second lead electrode 112 can be connected to the second electrode 115, and the other end of the second lead electrode 112 can be connected to the second part of the external circuit.

[0134] The first electrode 113, the second electrode 115, the first lead electrode 111, and the second lead electrode 112 can all be made of conductive materials, such as aluminum, copper, or gold. The number of the first lead electrodes 111 can correspond to the number of the first electrodes 113. At least one second lead electrode 112 can be provided, or multiple second lead electrodes 112 can be provided. The multiple second lead electrodes 112 can be connected to different positions of the second electrode 115.

[0135] The shapes of the first electrode 113 and the second electrode 115 can be the same or different. In the examples of this application, only the first electrode 113 is taken as an example for description. Exemplarily, the first electrode 113 can be in any one of other regular shapes such as cylindrical or prismatic, or in an irregular shape.

[0136] The shapes of the first lead electrode 111 and the second lead electrode 112 can be the same or different. Here, only the first lead electrode 111 is taken as an example for description.

[0137] Exemplarily, the first lead electrode 111 can include a first connection part and a second connection part connected to each other. One end of the first connection part is connected to the first electrode 113, and one end of the second connection part is connected to the external circuit. The cross-sectional shapes of the first connection part and the second connection part can be the same or different. For example, the cross-sectional shape of the first connection part can be circular, elliptical, polygonal, or irregular. The specific implementation manners of the first electrode 113, the second electrode 115, the first lead electrode 111, and the second lead electrode 112 are not limited in the examples of this application.

[0138] The second electrode 115 can be a conductive layer laid on the side of the resonant thin film 122 facing away from the resonant cavity 121. Only one second electrode 115 can be provided. The second electrode 115 can be used to ground the piezoelectric resonant pressure sensor 100.

[0139] The piezoelectric layer 114 can be disposed on the side of the second electrode 115 facing away from the resonant assembly 120. The piezoelectric layer 114 can be made of piezoelectric thin film material.

[0140] The first electrode 113 can be disposed on a side of the piezoelectric layer 114 away from the second electrode 115, and there can be at least two first electrodes 113. The first electrode 113 can include at least one driving electrode and at least one detecting electrode. The driving electrode is used to drive the piezoelectric layer 114 to vibrate, and the detecting electrode is used to detect the vibration of the piezoelectric layer 114.

[0141] The external circuit can be a detection circuit for detecting the output electrical signal of the piezoelectric resonant pressure sensor 100.

[0142] Next, please refer to Figure 8 and Figure 9 , and the principle of the piezoelectric resonant pressure sensor 100 will be further introduced in combination with the specific structure of the piezoelectric component 110.

[0143] The resonant component 120 and the piezoelectric component 110 can cooperate with each other to form a piezoelectric resonator, and the piezoelectric resonator can also include other structures.

[0144] When any one of the first electrodes 113 receives a voltage, based on the inverse piezoelectric effect of the piezoelectric layer 114, stress will be generated in the piezoelectric layer 114. At this time, since the neutral layer of the piezoelectric layer 114 deviates from the geometric center position of the piezoelectric layer 114, the piezoelectric layer 114 will be deformed, and the deformation of the piezoelectric layer 114 will drive the entire piezoelectric resonator to deform.

[0145] When an alternating voltage having the same resonant frequency as the piezoelectric resonator is applied to any one of the first electrodes 113, the entire structure will resonate, and the resonant frequency at this time is:

[0146]

[0147] In the formula, fr is the resonant frequency, μn is a constant set when solving the Bessel function, t is the thickness, r is the radius, E is the Young's modulus, ρ is the density, and δ is the Poisson's ratio.

[0148] When the pressure chamber 131 receives the pressure to be detected, the pressure-sensitive film 132 will be deformed and generate working stress under the action of the pressure to be detected. The connecting structure 123 can transfer the deformation and the generated working stress of the pressure-sensitive film 132 to the piezoelectric resonator, specifically to the piezoelectric layer 114. During the transfer process of the connecting structure 123, the connecting structure 123 can change the acting direction of the pressure to be detected and reduce the possibility of damage to the resonant film 122. The anchor point can utilize the lever principle to amplify the working stress and improve the measurement range of the piezoelectric resonant pressure sensor 100.

[0149] Since the piezoelectric resonator is provided with at least two first electrodes 113, when one of the first electrodes 113 drives the piezoelectric layer 114 to vibrate, the other first electrode 113 will detect the vibration of the piezoelectric resonator. The first electrode 113 receiving the voltage can be a driving electrode, and the first electrode 113 detecting the vibration can be a detecting electrode.

[0150] Due to the direct piezoelectric effect of the piezoelectric thin film material, the detecting electrode will generate an electrical signal. This electrical signal can be used to detect the resonant frequency of the piezoelectric resonator.

[0151] Let the working stress generated by the pressure to be detected on the piezoelectric resonator be σ, and the resonant frequency of the piezoelectric resonator at this time is:

[0152]

[0153] It can be seen from the above formula that when the frequency change of the piezoelectric resonator is detected, the pressure value can be determined.

[0154] When the piezoelectric layer 114 is deformed, the part of the piezoelectric layer 114 close to the resonant component 120 is squeezed under the action of the pressure to be detected, and the part of the piezoelectric layer 114 away from the resonant component 120 is stretched under the action of the pressure to be detected. On the cross-section of the piezoelectric layer 114, the transition layer that exists between the stretched part of the piezoelectric layer 114 and the squeezed part of the piezoelectric layer 114 and is neither tensile nor compressive and has almost zero stress is the neutral layer mentioned above.

[0155] Compared with the resistance detection type piezoelectric sensor that needs to set up a Wheatstone bridge and the capacitance detection type pressure sensor that needs to set up a capacitance bridge, the piezoelectric resonant pressure sensor 100 provided by the example of the present application does not need to set up an additional detection circuit, has a simpler structure, and lower manufacturing cost.

[0156] Based on the piezoelectric resonant pressure sensor 100 provided by the above example, Figure 10 is a schematic diagram of the internal structure of a piezoelectric resonant pressure sensor provided by the example of the present application. Refer to Figure 7 or Figure 10 , Figure 3 , Figure 7 and Figure 10 respectively represent schematic diagrams of the internal structures of piezoelectric resonant pressure sensors 100 with different structures. Figure 3 is used to schematically show the internal structure of the piezoelectric resonant pressure sensor 100 when no groove is provided in the piezoelectric resonant pressure sensor 100. Figure 7 is used to schematically show the internal structure of the piezoelectric resonant pressure sensor 100 when one kind of groove is provided in the piezoelectric resonant pressure sensor 100. Figure 10 is used to schematically show the internal structure of the piezoelectric resonant pressure sensor 100 when another kind of groove is provided in the piezoelectric resonant pressure sensor 100.

[0157] The piezoelectric resonant pressure sensor 100 is provided with at least one groove 170. The groove 170 can be disposed between the resonant film 122 and the pressure-sensitive film 132. Alternatively, the groove 170 can also be disposed on the side of the resonant assembly 120 away from the resonant substrate 133, and the notch of the groove 170 is opened away from the resonant substrate 133.

[0158] Exemplarily, please refer to Figure 10 , the resonant assembly 120 may further include a resonant substrate 124, and the resonant substrate 124 is disposed on the side of the pressure-sensitive assembly 130 away from the pressure chamber 131. Along the direction in which the resonant assembly 120 faces the pressure-sensitive assembly 130, the groove 170 can be disposed between the resonant film 122 and the pressure-sensitive film 132. Along the cross-sectional direction of the resonant cavity 121, the groove 170 is disposed between the resonant substrate 124 and the connection structure 123.

[0159] The groove 170 can keep a distance between the resonant substrate 124 and the connection structure 123, thereby reducing the cross-sectional area of the connection structure 123, making the working stress transmitted to the pressure-sensitive film 132 through the connection structure 123 more concentrated, which is beneficial to improving the detection accuracy of the piezoelectric resonant pressure sensor 100.

[0160] Exemplarily, please refer to Figure 7 , the resonant assembly 120 may further include a resonant substrate 124, and the setting manner of the resonant substrate 124 is similar to the setting manner of the resonant substrate 124 mentioned in the foregoing example, and the example of the present application will not be further described herein.

[0161] The groove 170 can also be disposed on the side of the resonant assembly 120 away from the resonant substrate 133, and the notch of the groove 170 is opened away from the resonant substrate 133.

[0162] The groove 170 mentioned in the example of the present application can keep a distance between the resonant substrate 124 and the connection structure 123, thereby reducing the cross-sectional area of the connection structure 123, making the working stress transmitted to the pressure-sensitive film 132 through the connection structure 123 more concentrated, which is beneficial to improving the detection accuracy of the piezoelectric resonant pressure sensor 100.

[0163] In addition, since the opening of the groove 170 mentioned in the examples of this application faces away from the resonant substrate 133, the notch of the groove 170 can be opened to the position where the piezoelectric component 110 is located, specifically, it can be opened to the side of the piezoelectric component 110 facing away from the resonant component 120. Based on this, the resonant component 120 can divide the piezoelectric layer 114 into at least two parts. Along the direction from the resonant cavity 121 to the pressure cavity 131, the projection of the groove 170 is located between the projection of at least one lead electrode and the projection of the resonant cavity 121. That is, the groove 170 can divide the piezoelectric component 110 into a part that vibrates under the action of the pressure to be detected and a part that hardly vibrates under the action of the pressure to be detected. At least one lead electrode can be located in the part of the piezoelectric component 110 that hardly vibrates. In this way, the influence of the pressure to be detected on the lead electrode can be reduced, the possibility of the lead electrode vibrating under the action of the pressure to be detected can be decreased, and thus the use reliability of the piezoelectric resonant pressure sensor 100 can be ensured.

[0164] In the case of only setting one groove, the piezoelectric resonant pressure sensor 100 can be provided with a lead bridge 171, or the lead bridge can not be set.

[0165] In the case of providing at least two grooves 170, a lead bridge 171 can be formed between two adjacent grooves 170, and the lead bridge 171 can be provided with one, two, three, four or more. Multiple lead bridges can be arranged in a cross shape, a cross-star shape, a linear shape or other irregular shapes in cooperation.

[0166] The number of lead bridges 171 can be equal to and in one-to-one correspondence with the number of the first lead electrodes 111, or the number of lead bridges 171 can also be less than the number of the first lead bridges 171. The examples of this application do not limit this. Specifically, reference can be made to Figures 11 to 15 , Figure 11 FIG. Figure 12 is a schematic structural diagram of a piezoelectric resonant pressure sensor without a lead electrode and a protective layer provided by the examples of this application. This structure is provided with 4 lead bridges. Figure 13 FIG. Figure 14 is a schematic structural diagram of a piezoelectric resonant pressure sensor without a lead electrode and a protective layer provided by the examples of this application. This structure is provided with 3 lead bridges. Figure 15 FIG.

[0167] By providing the lead bridge 171, a setting position can be provided for the lead connecting the first lead electrode 111 and the first electrode 113, and by adjusting the setting position of the first lead electrode 111, the connection reliability between the first lead electrode 111 and the first electrode 113 can be ensured.

[0168] Please refer to Figure 11 , a beam structure 172 can be provided at the setting position of the first electrode 113, and one or more beam structures 172 can be provided.

[0169] An angle can be formed between the beam structure 172 and the lead bridge 171.

[0170] Exemplarily, the angle between the beam structure 172 and the lead bridge 171 can be equal to zero, that is, the connection electrode between the first lead electrode 111 and the first electrode 113 can be linear, and the connection electrode can be provided on the lead bridge 171 to achieve the electrical connection between the first lead electrode 111 and the first electrode 113. At this time, the number of beam structures 172 can be equal to or different from the number of lead bridges 171. For example, when the number of beam structures 172 is equal to the number of lead bridges 171, the beam structure 172 and the lead bridge 171 can cooperate to form a linear structure, a cross structure, a star structure or other structures.

[0171] Exemplarily, the angle between the beam structure 172 and the lead bridge 171 can also be a non-zero angle, that is, the connection electrode between the first lead electrode 111 and the first electrode 113 is in a zigzag shape. At this time, the number of beam structures 172 can be equal to or different from the number of lead bridges 171. The specific implementation manners of the beam structure 172 and the lead bridge 171 are not limited in this application example.

[0172] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the piezoelectric component 110 can further include a seed layer, and the seed layer is provided between the piezoelectric component 110 and the resonant component 120, and specifically can be provided between the second electrode 115 and the resonant component 120.

[0173] By providing the seed layer, the working performance of the piezoelectric component 110 can be ensured, and further the working performance of the piezoelectric resonant pressure sensor 100 can be ensured.

[0174] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the resonant component 120 can be processed from a first SOI wafer (silicon on insulator), and the pressure sensitive component 130 can be processed from a second SOI wafer.

[0175] Next, taking the second SOI wafer as an example, the structure of the second SOI wafer will be briefly introduced in combination with the pressure sensitive component 130.

[0176] The second SOI wafer may include a connected second device layer, a second buried oxide layer, and a second substrate layer. A pressure chamber 131 may be processed on a side of the second substrate layer facing away from the second device layer. The bottom wall of the pressure chamber 131 may be a side of the second buried oxide layer facing the second substrate layer 430, or the bottom wall of the pressure chamber 131 may also be a side of the second buried oxide layer facing away from the second substrate layer.

[0177] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, please refer to Figure 10 , an oxide layer 150 is provided between the pressure sensitive component 130 and the resonant component 120.

[0178] The oxide layer 150 may be the oxide layer 150 formed during the connection process of the first SOI wafer and the second SOI wafer, or the oxide layer 150 may be specifically provided between the first SOI wafer and the second SOI wafer.

[0179] By providing the oxide layer 150, the insulation between the pressure sensitive component 130 and the resonant component 120 can be ensured, the possibility of leakage of the piezoelectric resonant pressure sensor 100 can be reduced, and the use safety of the piezoelectric resonant pressure sensor 100 can be guaranteed.

[0180] In addition, since the pressure sensitive film 132 is located on one side of the trench 170, based on this, by providing the oxide layer 150, the processing depth of the trench 170 can be ensured, and the possibility of damage to the pressure sensitive film 132 during the processing of the trench 170 can be reduced.

[0181] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, please refer to Figure 10 , the pressure sensitive component 130 may further include a second buried oxide layer 420, and the side wall of the second buried oxide layer 420 cooperates with the side wall of the resonant substrate 133 to form the side wall of the pressure chamber 131.

[0182] By providing the second buried oxide layer 420, the processing depth of the pressure chamber 131 can be ensured, thereby ensuring the thickness of the pressure sensitive film 132, ensuring the strength of the pressure sensitive film 132, and reducing the possibility of damage to the pressure sensitive film 132 caused by the impact of the pressure to be detected.

[0183] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, Figure 16 For the structural schematic diagram of another piezoelectric resonant pressure sensor provided in the example of this application, please refer to Figure 16 , the piezoelectric resonant pressure sensor 100 may further include a cover 160, the cover 160 is provided on a side of the piezoelectric component 110 facing away from the pressure sensitive component 130, and the cover 160 is directly or indirectly connected to the piezoelectric component 110.

[0184] The cover 160 can be made of a silicon wafer, a glass wafer, an inorganic semiconductor material, or other amorphous inorganic non-metallic materials.

[0185] In a vacuum environment, the cover 160 can be used to encapsulate the piezoelectric resonator. The cover 160 can be disposed on the side of the piezoelectric component 110 facing away from the resonant component 120 to isolate the piezoelectric component 110 from the atmospheric environment, ensuring that the piezoelectric component 110 operates in a vacuum environment, thereby increasing the value corresponding to the quality factor of the piezoelectric resonant pressure sensor 100 and ensuring the operating performance of the piezoelectric resonant pressure sensor 100.

[0186] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, please refer to Figure 10 , a protective layer 140 can be provided on the side of the piezoelectric component 110 facing away from the resonant component 120. The protective layer 140 can be made of silicon dioxide material or other moisture-proof materials.

[0187] The protective layer 140 can isolate the piezoelectric component 110 from the atmospheric environment, and the protective layer 140 can play a role in moisture-proofing, enabling the piezoelectric resonant pressure sensor 100 to be maintained in a dry state as much as possible, ensuring the operating reliability of the piezoelectric resonant pressure sensor 100. The protective layer 140 can also play a role in temperature compensation during the operation of the piezoelectric resonant pressure sensor 100.

[0188] During the use of the piezoelectric resonant pressure sensor 100, only the cover 160 can be provided, or only the protective layer 140 can be provided, or both the cover 160 and the protective layer 140 can be provided, or neither the cover 160 nor the protective layer 140 can be provided. The examples of this application do not make specific restrictions on this.

[0189] Exemplarily, the examples of this application provide a method for manufacturing a piezoelectric resonant pressure sensor 100. This method is applicable to the piezoelectric resonant pressure sensor 100 provided in any of the above examples, and the following processing methods can be completed by MEMS processing equipment. This method is used to process the first SOI wafer and the second SOI wafer into the piezoelectric resonant pressure sensor 100.

[0190] The first SOI wafer includes a first device layer 310, a first buried oxide layer 320, and a first substrate layer 330. The second SOI wafer includes a second device layer 410, a second buried oxide layer 420, and a second substrate layer 430. The thickness of the first device layer 310 is equal to the sum of the height of the resonant cavity 121 and the thickness of the resonant film 122. The thickness of the second device layer 410 is equal to the thickness of the pressure-sensitive film 132. Figure 17 For a schematic flow diagram of a method for manufacturing a piezoelectric resonant pressure sensor provided in the examples of this application, please refer to Figure 17 , this method specifically includes the following steps:

[0191] S201. Take the first SOI wafer and process the resonant cavity 121 on the first device layer 310. Figure 18 The structural schematic diagram of the first SOI wafer before processing provided for the example of this application Figure 19 The structural schematic diagram of the first SOI wafer processed with a resonant cavity and a trench provided for the example of this application. For details, please refer to Figure 18 and Figure 19 .

[0192] The resonant cavity 121 can be formed by etching, sputtering or other processing methods on the side of the first device layer 310 facing away from the first buried oxide layer 320. The thickness of the first device layer 310 is equal to the sum of the thickness of the resonant film 122 and the height of the resonant cavity 121. The etching can include dry etching and wet etching. The dry etching includes but is not limited to xenon difluoride and plasma etching, and the wet etching includes but is not limited to HF etching and electrochemical etching.

[0193] The thickness of the above-mentioned first device layer 310, the thickness of the resonant film 122, and the height of the resonant cavity 121 all refer to the corresponding dimensions of the first device layer 310, the resonant film 122, and the resonant cavity 121 along the direction from the first buried oxide layer 320 to the first device layer 310.

[0194] In some possible implementation manners, the piezoelectric resonant pressure sensor 100 includes a trench 170, and there are various processing methods for the trench 170.

[0195] Exemplarily, based on the preparation method provided in the above example, in S201, when taking the first SOI wafer and processing the resonant cavity 121 on the first device layer 310, the preparation method may further include:

[0196] S2011. Process at least one first trench on the first device layer 310. For details, please refer to Figure 19 , Figure 19 The structural schematic diagram of the first SOI wafer processed with a resonant cavity and a trench provided for the example of this application.

[0197] The depth of the above-mentioned first trench and the height of the resonant cavity 121 may be the same or different. The first trench and the resonant cavity 121 can be processed simultaneously, or the first trench can be processed before processing the resonant cavity 121, or the first trench can be processed after processing the resonant cavity 121. The example of this application does not limit this.

[0198] In the case where the first trench is processed, when bonding the first device layer 310 and the second device layer 410, the second device layer 410 can close the notch of the first trench.

[0199] In some possible implementations, when at least one first trench is processed in the first device layer 310, the preparation method may further include:

[0200] S2013, based on the set position of the first trench, process a second trench from the piezoelectric component 110, and the second trench communicates with the first trench to form a trench 170.

[0201] S202, take a second SOI wafer, bond the second device layer 410 to the first device layer 310, and the second device layer 410 seals the resonant cavity 121. Among them, an oxide layer 150 is formed between the second device layer 410 and the first device layer 310 during the bonding process. Figure 20 This is a schematic structural diagram of a first SOI wafer after processing a resonant cavity and trenches and then being flipped according to an example of the present application. Figure 21 This is a schematic structural diagram of a second SOI wafer before processing according to an example of the present application. Figure 22 This is a schematic structural diagram of a first SOI wafer and a second SOI wafer bonded and connected according to an example of the present application. Specifically, refer to Figures 20 to 22 .

[0202] By using the first SOI wafer, the first device layer 310 can also face the second device layer 410, which is convenient for realizing the bonding between the first device layer 310 and the second device layer 410, and enabling the second device layer 410 to close the cavity opening of the resonant cavity 121.

[0203] By flipping the second SOI wafer, the second device layer 410 can face the first device layer 310, which is convenient for realizing the bonding between the first device layer 310 and the second device layer 410, and enabling the second device layer 410 to close the cavity opening of the resonant cavity 121. The bonding can be anodic bonding, fusion bonding or other bonding methods.

[0204] S203, remove the first buried oxide layer 320 and the first substrate layer 330, and part of the first device layer 310 serves as the resonant film 122. Figure 23 This is a schematic structural diagram of a first SOI wafer and a second SOI wafer bonded and connected and after removing the first substrate layer and the first buried oxide layer according to an example of the present application. Specifically, refer to Figure 23 .

[0205] The present application example does not specifically limit the removal method of the first buried oxide layer 320 and the oxide layer 150.

[0206] Removing the first buried oxide layer 320 and the first substrate layer 330 can expose the first device layer 310, which is convenient for subsequent processing.

[0207] S204, arrange the piezoelectric component 110 on the side of the first device layer 310 facing away from the second SOI wafer. Specifically, refer toFigure 24 , Figure 24 Schematic diagram of a structure for depositing a piezoelectric component on the side of the first device layer facing away from the second SOI wafer provided in the example of this application.

[0208] The piezoelectric component 110 can be disposed on the side of the first device layer 310 facing away from the second SOI wafer by deposition or other means.

[0209] In some possible implementation manners, the piezoelectric component 110 includes a lead electrode, a first electrode 113, a piezoelectric layer 114, and a second electrode 115. S204 specifically includes the following steps:

[0210] S2041, deposit a second electrode layer, a piezoelectric layer 114, and a first electrode layer in sequence, specifically referring to Figure 24 .

[0211] S2042, pattern the first electrode layer to form at least two first electrodes 113, specifically referring to Figure 25 , Figure 25 Schematic diagram of a structure based on Figure 24 after processing the piezoelectric component provided in the example of this application.

[0212] In some possible implementation manners, after S2042, the following steps may further be included:

[0213] S2411, deposit a protective layer 140, specifically referring to Figure 26 , Figure 26 Schematic diagram of a structure for disposing a protective layer on the side of the piezoelectric component facing away from the first device layer provided in the example of this application. Figure 25

[0214] Since the patterning of the first electrode 113 has been performed before depositing the protective layer 140, part of the piezoelectric layer 114 is exposed. Therefore, part of the protective layer 140 can be in contact with the first electrode 113, and another part of the protective layer 140 can be in contact with the piezoelectric layer 114.

[0215] Figure 27 S2412, process a first connection hole 1111 at the position connecting the first electrode 113, and a conductive structure passing through the first connection hole 1111 can be connected to the first electrode 113. Specifically referring to Figure 27 , Figure 26 Schematic diagram of a structure for processing a first connection hole from a protective layer provided in the example of this application.

[0216] ​​The first connection hole 1111 can be processed on the side of the first electrode 113 facing away from the resonant component 120. Part of the hole wall of the first connection hole 1111 can also be provided on the first electrode 113, as long as it is ensured that the conductive structure passing through the first connection hole 1111 can be connected to the first electrode 113. The present application example does not make specific restrictions on this.

[0217] S2413, at the position of connecting the second electrode 115, process the second connection hole 1121. The connecting member passing through the second connection hole 1121 can be connected to the second electrode 115. Specifically, reference can be made to Figure 28 , Figure 28 which is a schematic structural diagram of processing the second connection hole from the protective layer provided by the example of the present application. Figure 27 is different from the cross-section direction of Figure 28 and Figure 27 .

[0218] The second connection hole 1121 can be processed on the side of the second electrode 115 facing away from the resonant component 120. Part of the hole wall of the second connection hole 1121 can also be provided on the second electrode 115, as long as it is ensured that the conductive structure passing through the second connection hole 1121 can be connected to the second electrode 115. The present application example does not make specific restrictions on this.

[0219] S2043, deposit the lead electrode layer. Part of the lead electrode layer can be located in the second connection hole 1121 and connected to the second electrode 115. Specifically, reference can be made to Figure 29 , Figure 29 which is a schematic structural diagram of depositing the lead electrode layer on the side of the protective layer facing away from the first device layer provided by the example of the present application. Figure 28

[0220] S2044, pattern the lead electrode layer to form at least one first lead electrode 111 and at least one second lead electrode 112. Specifically, reference can be made to Figure 30 , Figure 30 which is a schematic structural diagram of processing the lead electrode layer provided by the example of the present application. Figure 29

[0221] One side of the first lead electrode 111 close to the first electrode 113 is connected to the first electrode 113, and the side of the first lead electrode 111 facing away from the first electrode 113 can be connected to the first part of the external circuit. One side of the second lead electrode 112 close to the second electrode 115 is connected to the second electrode 115, and the side of the second lead electrode 112 facing away from the second electrode 115 can be connected to the second part of the external circuit. The second lead electrode 112 is the conductive structure mentioned in the above example. Based on this, the connection between the piezoelectric resonant pressure sensor 100 and the external circuit can be realized.

[0222] ​​S205. Open a pressure chamber 131 on the second liner layer 430 and form a pressure-sensitive film 132. At least part of the pressure-sensitive film 132 closes the resonant cavity 121. For details, please refer to Figure 31 , Figure 31 a structure diagram provided by an example of this application based on Figure 30 a schematic structural diagram of processing a pressure chamber on the side of the second SOI wafer away from the first device layer.

[0223] The processing method of the pressure chamber 131 is similar to that of the resonant cavity 121, and this will not be elaborated in this example of this application.

[0224] The pressure chamber 131 can be opened on the side of the pressure-sensitive component 130 away from the resonant component 120, and a pressure-sensitive film 132 is formed at the position where the pressure chamber 131 is opened on the pressure-sensitive component 130. It can be understood that along the direction from the resonant component 120 to the pressure-sensitive component 130, at least part of the projection of the resonant cavity 121 falls within the projection range of the pressure chamber 131.

[0225] For example, the projection of the resonant cavity 121 can completely fall within the projection range of the pressure chamber 131. At this time, the geometric center of the projection of the resonant cavity 121 can overlap with the geometric center of the projection of the pressure chamber 131, or there can be a distance between the geometric center of the resonant cavity 121 and the geometric center of the pressure chamber 131.

[0226] For example, the projection of part of the resonant cavity 121 can fall within the projection range of the pressure chamber 131, that is to say, the projection of the resonant cavity 121 and the projection of the pressure chamber 131 partially overlap.

[0227] This application does not specifically limit the positional relationship between the resonant cavity 121 and the pressure chamber 131, as long as it is ensured that at least part of the projection of the resonant cavity 121 coincides with the projection of the pressure chamber 131, so as to ensure that the pressure to be detected received by the pressure chamber 131 can be transmitted to the piezoelectric component 110 through the resonant cavity 121, and the piezoelectric component 110 can detect the pressure to be detected.

[0228] Exemplarily, after S205, opening the pressure chamber 131 on the second liner layer 430 and forming the pressure-sensitive film 132, the preparation method may further include:

[0229] S2014. Process a groove 170 on the side of the piezoelectric component 110 away from the first device layer 310. The groove 170 is spaced from the resonant cavity 121. For details, please refer to Figure 32 , Figure 32 a structure diagram provided by an example of this application based on Figure 31 a schematic structural diagram of processing a groove from the protective layer.

[0230] In the examples of the present application, the notch of the groove 170 can be opened away from the resonant substrate 133. The bottom of the groove 170 can be at least part of the oxide layer 150, or at least part of the second device layer 410, or at least part of other structures. The present application examples do not limit the specific opening of the groove 170.

[0231] For the piezoelectric resonant pressure sensor 100 processed based on the above preparation method, the pressure chamber 131 can receive the pressure to be detected. The pressure to be detected can be transmitted to the piezoelectric component 110 and the resonant component 120 through the pressure sensitive component 130, and the pressure to be detected is detected through the characteristics of the piezoelectric component 110. Since the piezoelectric component 110 is arranged on the side of the resonant component 120 away from the pressure sensitive component 130, the piezoelectric component 110 is separated from the pressure chamber 131 that receives the pressure to be detected. And since there is a resonant cavity 121 on the resonant component 120. When the piezoelectric component 110 drives the resonant component 120 to vibrate, the resonant cavity 121 can provide a deformation space for the piezoelectric component 110, reducing the possibility that the piezoelectric component 110 has a large deformation due to vibration and thus being damaged.

[0232] When the possibility of the piezoelectric component 110 being damaged is reduced, the piezoelectric resonant pressure sensor 100 provided by the present application examples can withstand a larger pressure to be detected, thereby increasing the pressure measurement range of the piezoelectric resonant pressure sensor 100, expanding the measurement range of the piezoelectric resonant pressure sensor 100, expanding the applicable range of the piezoelectric resonant pressure sensor 100, and enabling the piezoelectric resonant pressure sensor 100 to be widely used in the technical field of the electronic core industry.

[0233] In addition, in the present application examples, since a pressure sensitive film 132 is formed at the position where the pressure sensitive component 130 opens the pressure chamber 131, and at least part of the pressure sensitive film 132 closes the resonant cavity 121, the resonant cavity 121 and the pressure chamber 131 at least partially overlap. Based on this, the volume of the resonant piezoelectric sensing can be reduced, which is beneficial to the miniaturization of the piezoelectric resonant pressure sensor 100 and the integrated development of the piezoelectric resonant pressure sensor 100.

[0234] In some possible implementation manners, the piezoelectric resonant pressure sensor 100 may further include a cover, and the above preparation method may further include:

[0235] S206, take a glass wafer 500 and etch a cavity to form a cover 160. Specifically, reference can be made to FIGS. 33 and Figure 34 , Figure 33 which is a schematic structural diagram of a glass wafer provided by the present application examples, Figure 34A schematic diagram of a structure for machining a cavity on a glass wafer to form a cover is provided as an example of the present application.

[0236] S207, in a vacuum environment, bonding the cover 160 and the piezoelectric component together. For details, please refer to Figure 35 , Figure 35 A schematic diagram of a glass wafer connected to the side of the protective layer away from the piezoelectric layer provided for the example of this application. The bonding method can be anodic bonding, or metal bonding such as Al-Ge, Au-Au, or other bonding methods.

[0237] The above-mentioned numbers do not limit the order of the steps of the above-mentioned method. During the specific implementation of the preparation method, the implementation steps of the above-mentioned method can be adaptively adjusted based on actual conditions.

[0238] During the detection process of the piezoelectric resonant pressure sensor 100, the detection of the piezoelectric resonant pressure sensor 100 is easily affected by environmental factors, which may affect the detection result of the piezoelectric resonant pressure sensor 100. Environmental factors may be temperature, vibration, impact, etc. Based on this, the piezoelectric resonant pressure sensor 100 needs to be compensated.

[0239] Exemplarily, the present application provides a compensation system 200, Figure 36 For a schematic diagram of the compensation system provided for this application example, please refer to Figure 36 The compensation system 200 may include an integrated driving component 230, a detection component 240 and at least two piezoelectric resonant pressure sensors 100 mentioned in the above embodiments, and the at least two piezoelectric resonant pressure sensors 100 include at least one pressure sensor 210 and at least one compensation sensor 220.

[0240] When only one pressure sensor 210 is provided, only one compensation sensor 220 may be provided, or a plurality of compensation sensors 220 may be provided.

[0241] When only one compensation sensor 220 is provided, only one detection sensor may be provided, or a plurality of detection sensors may be provided.

[0242] Multiple compensation sensors 220 and detection sensors may be provided, and the number of compensation sensors 220 may be equal to the number of detection sensors, or the number of compensation sensors 220 may be different from the number of detection sensors.

[0243] The pressure sensor 210 is used to detect the pressure to be detected, and the compensation sensor 220 is used to compensate for the influence of environmental factors on the pressure sensor 210. The driving component 230 is connected to the driving electrode of the pressure sensor 210 and the driving electrode of the compensation sensor 220. The driving component 230 is used to drive the detection sensor and the compensation sensor 220 to vibrate. The detection component 240 is connected to the detection electrode of the pressure sensor 210 and the detection electrode of the compensation sensor 220. The detection component 240 is used to detect the resonance frequencies of the pressure sensor 210 and the compensation sensor 220.

[0244] Since the pressure sensor 210 and the compensation sensor 220 are integrated together and have the same resonance component 120, environmental factors such as temperature, vibration, and shock will have the same influence on the resonance component 120 of the pressure sensor 210 and the compensation sensor 220. Therefore, the resonance component 120 of the pressure sensor 210 and the compensation sensor 220 can have the same output based on the influence of environmental factors.

[0245] Based on this, when the detection component 240 detects the resonance frequencies of the pressure sensor 210 and the compensation sensor 220, as long as the resonance frequency output by the pressure sensor 210 is subtracted from the resonance frequency output by the compensation sensor 220, and then the final resonance frequency is extracted, the influence of environmental factors can be excluded, and the detection accuracy of the compensation system 200 for the pressure to be detected can be improved.

[0246] Figure 37 The following is a schematic diagram of the working process of a compensation system provided by an example of this application. Please refer to Figure 37 The working process of the compensation sensor 220 is specifically as follows:

[0247] S101, the driving component 230 is used to drive the pressure sensor 210 and the compensation sensor 220.

[0248] S102, the detection component 240 is used to detect and output the first resonance frequency corresponding to the pressure sensor 210 and the second resonance frequency corresponding to the compensation sensor 220.

[0249] S103, the calculation module is used to calculate the difference between the first resonance frequency and the second resonance frequency to obtain the target resonance frequency.

[0250] S104, the calculation module can also calculate the pressure value of the pressure to be detected based on the resonance frequency.

[0251] The calculation module can be a part of the detection component 240, or the calculation module can be a module independent of the detection component 240. This application example does not limit this.

[0252] Based on the compensation system 200 mentioned in the above example, during the operation of the compensation system 200, the pressure to be detected can act on the pressure chamber 131 of the pressure sensor, and the pressure to be detected does not act on the compensation sensor 220. Based on this, the structures of the pressure-receiving sensor 210 and the compensation sensor 220 can be exactly the same. The structures of the pressure-receiving sensor 210 and the compensation sensor 220 can also be different. For example, the compensation sensor 220 may not be provided with the pressure-sensitive component 130. The specific structures of the pressure-receiving sensor 210 and the compensation sensor 220 are not limited in the examples of this application.

[0253] In summary, according to the compensation system 200 provided by the examples of this application, when the detection component 240 detects the resonance frequencies of the pressure-receiving sensor 210 and the compensation sensor 220, as long as the resonance frequency output by the pressure-receiving sensor 210 is subtracted from the resonance frequency output by the compensation sensor 220, and then the final resonance frequency is extracted, the influence of environmental factors can be excluded, and the detection accuracy of the compensation system 200 for the pressure to be detected can be improved.

[0254] Finally, it should be noted that the above embodiments are only specific implementation manners of this application, but the protection scope of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be covered by the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

Claims

1. A piezoelectric resonant pressure sensor, used in the core electronics industry, characterized in that: include: A piezoelectric component is directly or indirectly connected to an external circuit; A resonant component is arranged on one side of the piezoelectric component, and a resonant cavity is provided on a side of the resonant component away from the piezoelectric component; A pressure sensitive component is connected to a side of the resonant component away from the piezoelectric component, and a pressure cavity is provided on the side of the pressure sensitive component away from the resonant component, and the pressure cavity is used to receive the pressure to be detected; The position where the pressure sensitive component opens the pressure cavity forms a pressure sensitive film, and at least part of the pressure sensitive film closes the resonance cavity. The resonance component includes a connecting structure and a resonance film that are connected to each other. The connecting structure and the resonance film cooperate to form the resonance cavity. The resonance film is located on the side of the connecting structure that is away from the pressure sensitive component, and the connecting structure can change the direction of action of the pressure to be detected.

2. The piezoelectric resonant pressure sensor according to claim 1, characterized in that: The pressure cavity is provided at the position where the pressure sensitive component closes the resonance cavity.

3. The piezoelectric resonant pressure sensor according to claim 1, characterized in that: The pressure sensitive component further includes a resonant substrate. The pressure sensitive film cooperates with the resonant substrate to form the pressure chamber. The resonant substrate is located on a side of the pressure sensitive film away from the resonant component.

4. The piezoelectric resonant pressure sensor according to claim 1, characterized in that: A side of the connection structure close to the pressure sensitive component is an anchor point, a distance between the anchor point and the resonant film is a first distance, a distance between the anchor point and the pressure sensitive component is a second distance, and the first distance is greater than the second distance.

5. The piezoelectric resonant pressure sensor according to claim 1, characterized in that: The piezoelectric component includes a first lead electrode, a second lead electrode, a first electrode, a piezoelectric layer and a second electrode; wherein, The second electrode is disposed on a side of the resonant component away from the pressure sensitive component, and a side of the second electrode facing the resonant component is directly or indirectly connected to the resonant component; The piezoelectric layer is arranged on a side of the second electrode away from the resonant component, and a side of the piezoelectric layer facing the second electrode is connected to the second electrode; The first electrode is disposed on a side of the piezoelectric layer away from the second electrode, and a side of the piezoelectric layer facing the first electrode is connected to the first electrode; The first lead electrode is arranged on a side of the first electrode facing away from the piezoelectric layer, one end of the first lead electrode is connected to the first electrode, and the other end of the first lead electrode is connected to a first part of the external circuit; the second lead electrode is arranged on a side of the second electrode facing the piezoelectric layer, one end of the second lead electrode is connected to the second electrode, and the other end of the second lead electrode is connected to a second part of the external circuit.

6. The piezoelectric resonant pressure sensor according to claim 3, characterized in that: The piezoelectric resonant pressure sensor is provided with at least one groove, and the groove is provided between the resonant film and the pressure sensitive film; or, The groove is arranged on a side of the resonant component away from the resonant substrate, and a notch of the groove is opened away from the resonant substrate.

7. The piezoelectric resonant pressure sensor according to claim 1, characterized in that: It also includes a cover, which is arranged on a side of the piezoelectric component away from the pressure sensitive component, and the cover is directly or indirectly connected to the piezoelectric component.

8. A compensation system, characterized in that: It comprises an integrated driving component, a detection component and at least two piezoelectric resonant pressure sensors according to any one of claims 1 to 7, wherein the at least two piezoelectric resonant pressure sensors comprise at least one pressure sensor and at least one compensation sensor.

9. A method for preparing a piezoelectric resonant pressure sensor, characterized in that: The piezoelectric resonant pressure sensor according to any one of claims 1 to 7 is applied to the method for processing the piezoelectric resonant pressure sensor from a first SOI wafer and a second SOI wafer, wherein the first SOI wafer comprises a first device layer, a first buried oxide layer and a first substrate layer, and the second SOI wafer comprises a second device layer, a second buried oxide layer and a second substrate layer; the thickness of the first device layer is equal to the sum of the height of the resonant cavity and the thickness of the resonant film, and the thickness of the second device layer is equal to the thickness of the pressure sensitive film; The method comprises: Taking a first SOI wafer, processing a resonant cavity on the first device layer, and forming a connection structure around the resonant cavity; Taking a second SOI wafer, bonding the second device layer to the first device layer, wherein the second device layer seals the resonant cavity, wherein an oxide layer is formed between the second device layer and the first device layer during the bonding process; The first buried oxide layer and the first substrate layer are removed, and part of the first device layer is used as a resonant film; Disposing a piezoelectric component on a side of the first device layer facing away from the second SOI wafer; The pressure cavity is opened on the second substrate layer, and a pressure sensitive film is formed, wherein at least a portion of the pressure sensitive film closes the resonance cavity.

Images