Piezoelectric resonant pressure sensor and compensation system

Abstract

The utility model provides a piezoelectric resonant pressure sensor and a compensation system, and relates to the technical field of sensitive element and sensor manufacturing in the electronic core industry. The piezoelectric resonant pressure sensor comprises a piezoelectric assembly, a resonant film and a pressure resonant assembly. The resonant film is arranged on one side of the piezoelectric assembly and is connected with the piezoelectric assembly. The pressure resonance assembly is arranged on one side of the resonance film and connected with the resonance film, a resonance groove is formed in the side, facing the resonance film, of the pressure resonance assembly, the resonance groove and the resonance film are matched to form a resonance cavity, and a pressure cavity is formed in the side, deviating from the resonance film, of the pressure resonance assembly. The projection of the resonant cavity at least partially falls into the projection range of the pressure cavity in the direction from the resonant film to the pressure resonant assembly. According to the piezoelectric resonant pressure sensor provided by the embodiment of the invention, the pressure measurement range of the piezoelectric resonant pressure sensor can be expanded, and the application range of the piezoelectric resonant pressure sensor is further expanded.

Description

Technical Field

[0001] The present application relates to the technical field of sensitive components and sensor manufacturing in the core electronics industry, and in particular to a piezoelectric resonant pressure sensor and compensation system. Background Art

[0002] Pressure sensors can convert received pressure signals into electrical signals according to certain rules and output the electrical signals to other devices. They are sensitive components. Pressure sensors are widely used in defense, automobile, petroleum, aerospace, smart hardware and other technical fields, and belong to the core electronic industry technology field.

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

[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, piezoelectric resonant pressure sensors have the advantages of good stability and high accuracy, and are widely used in areas with high accuracy requirements and harsh environments, such as aerospace, petroleum, etc.

[0005] Based on the structure of the existing piezoelectric resonant pressure sensor, the pressure detection range of the piezoelectric resonant pressure sensor is relatively small, which may affect the application scope of the piezoelectric resonant pressure sensor. Utility Model Content

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

[0007] The first aspect of the present application provides a piezoelectric resonant pressure sensor, which is applied to the core electronic industry. The piezoelectric resonant pressure sensor includes a piezoelectric component, a resonant film and a pressure resonant component.

[0008] Wherein, the piezoelectric component is directly or indirectly connected to the external circuit. The resonant film is arranged on one side of the piezoelectric component, and the resonant film is directly or indirectly connected to the piezoelectric component. The pressure resonance component is arranged on one side of the resonant film and is connected to the resonant film. A resonant groove is arranged on the side of the pressure resonance component facing the resonant film. The resonant film is arranged at the opening of the resonant groove, and the resonant groove and the resonant film cooperate to form a resonant cavity. A pressure cavity is arranged on the side of the pressure resonance component away from the resonant film. A pressure-sensitive film is arranged between the resonant groove and the pressure cavity, and the pressure cavity is used to receive the pressure to be detected. Wherein, along the direction from the resonant film to the pressure resonance component, the projection of the resonant cavity at least partially falls within the projection range of the pressure cavity.

[0009] 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 film through the pressure resonance 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 film away from the pressure resonance component, the pressure chamber of the piezoelectric component that receives the pressure to be detected is arranged at intervals. And since the resonant groove of the pressure resonance component cooperates with the resonant film to form a resonant cavity. When the piezoelectric component drives the pressure resonance component to vibrate, the resonant cavity can provide deformation space for the piezoelectric component, reducing the possibility of the piezoelectric component being damaged due to a large deformation amount caused by vibration.

[0010] 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 100 can be widely used in the core technology field of the electronics industry.

[0011] In addition, in the example of the present application, since the projection of the resonant cavity at least partially falls within the projection range of the pressure cavity along the direction from the resonant film to the pressure resonant component, that is, 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.

[0012] In some possible implementations, at least a portion of an oxide layer is provided at a connection between the resonant film and the pressure resonance component.

[0013] The oxide layer can ensure the insulation between the resonant film and the pressure resonant component, thereby ensuring the reliability of the piezoelectric resonant pressure sensor.

[0014] The oxide layer can also reduce the impact of temperature in environmental factors on the piezoelectric resonant pressure sensor, thereby ensuring the measurement accuracy of the resonant pressure sensor.

[0015] In some possible implementations, the resonance film is bonded to the pressure resonance component, and at least a partial oxide layer is formed at the bonding location between the resonance film and the pressure resonance component.

[0016] The resonant film and the pressure resonant component can be connected together by anodic bonding, melt bonding or other bonding methods. The oxide layer formed at the bonding connection between the resonant film and the pressure resonant component can ensure the connection reliability between the resonant film and the pressure resonant component, thereby ensuring the reliability of the piezoelectric resonant pressure sensor.

[0017] In some possible implementations, the resonant film is processed from an SOI wafer, the pressure resonance component is processed from an Si wafer, the device layer of the SOI wafer is bonded to the Si wafer, and at least a partial oxide layer is formed at the connection position between the SOI wafer and the Si wafer.

[0018] In some possible implementations, along the direction from the resonance film to the pressure resonance component, the projection of the resonance cavity falls within the projection range of the pressure cavity.

[0019] By following the direction from the resonant cavity to the pressure cavity, the projection of the resonant cavity can completely fall within the projection range of the pressure cavity. In this way, the volume of the piezoelectric resonant pressure sensor can be further reduced, which is conducive to the miniaturization of the piezoelectric resonant pressure sensor.

[0020] In some possible implementations, the pressure resonance component includes at least one connection structure, which is disposed on a side of the pressure resonance component facing the pressure sensitive film, and the at least one connection structure cooperates with the pressure sensitive film to form a resonance groove.

[0021] 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 deformation caused by vibration. The connection structure can directly or indirectly connect the pressure sensitive film and the piezoelectric component, and the connection structure can change the direction of action of the pressure to be detected, so that the pressure to be detected acting vertically on the piezoelectric component is smaller, reducing the possibility of damage to the piezoelectric component, improving the pressure bearing capacity of the resonant film, 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.

[0022] In some possible implementations, the pressure resonance component further includes at least one resonance substrate, which is disposed on a side of the pressure resonance component away from the resonance film, and the at least one resonance substrate cooperates with the pressure sensitive film to form a pressure chamber.

[0023] By setting a resonant substrate, the resonant substrate and the pressure-sensitive film cooperate to form a pressure chamber. The operator can control the gas or liquid or other fluid to apply pressure to the cavity wall of the pressure chamber. By setting the pressure chamber, the force on the pressure-sensitive film can be more concentrated, which is convenient for the operator to apply the pressure to be detected to the cavity wall of the pressure chamber.

[0024] In some possible implementations, the piezoelectric resonant pressure sensor further includes a cover, which is disposed on a side of the piezoelectric component facing away from the pressure resonance component, and the cover is directly or indirectly connected to the piezoelectric component.

[0025] The cover can isolate the piezoelectric component from the atmospheric environment, ensuring that the piezoelectric component is in a vacuum environment when working, thereby improving the value corresponding to the quality factor of the piezoelectric resonant pressure sensor and ensuring the working performance of the piezoelectric resonant pressure sensor.

[0026] In some possible implementations, the piezoelectric resonant pressure sensor further includes a protective layer, where the protective layer is disposed on a side of the piezoelectric component facing away from the resonant component.

[0027] By providing a protective layer, the piezoelectric component can be isolated from the atmospheric environment, and the protective layer can play a role in moisture-proofing, so that the resonant pressure sensor is kept in a dry state as much as possible, ensuring the working reliability of the resonant pressure sensor. The protective layer can also play a role in temperature compensation during the working process of the resonant pressure sensor.

[0028] A second aspect of the present application provides a compensation system, which includes an integrated driving component, a detection component and a piezoelectric resonant pressure sensor mentioned in any of the above examples, at least two piezoelectric resonant pressure sensors including at least one pressure sensor and at least one compensation sensor.

[0029] Since the pressure sensor and the compensation sensor are integrated together and have the same resonant film, environmental factors such as temperature, vibration, and impact will have the same impact on the resonant films of the pressure sensor and the compensation sensor, so that the resonant films of the pressure sensor and the compensation sensor can have the same output based on the influence of environmental factors.

[0030] Based on this, when the detection component detects the resonant frequency of the pressure sensor and the compensation sensor, it only needs to subtract the resonant frequency output by the compensation sensor from the resonant frequency output by the pressure sensor and then extract the final resonant frequency, thereby eliminating the influence of environmental factors and improving the detection accuracy of the compensation system for the pressure to be detected. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 A schematic diagram of the structure of a piezoelectric resonant pressure sensor provided as an example in this application.

[0032] Figure 2 A top view of a schematic structural diagram of a piezoelectric resonant pressure sensor provided as an example in this application.

[0033] Figure 3 for Figure 2 Sectional view of AA.

[0034] Figure 4 for Figure 2 Cross-sectional view of BB.

[0035] Figure 5 A schematic diagram of the structure of another piezoelectric resonant pressure sensor provided as an example in this application.

[0036] Figure 6 A top view of a schematic structural diagram of another piezoelectric resonant pressure sensor provided as an example in this application.

[0037] Figure 7 for Figure 6 Middle CC section view.

[0038] Figure 8 for Figure 7 A partial enlarged view of point A in the middle.

[0039] Fig. 9 A schematic diagram of the working principle of a piezoelectric resonant pressure sensor provided as an example in this application.

[0040] Fig.10 A schematic diagram of the resonance principle of a piezoelectric resonant pressure sensor provided as an example in this application.

[0041] Fig.11 A schematic diagram of the internal structure of a piezoelectric resonant pressure sensor provided as an example in this application.

[0042] Fig.12 A schematic diagram of the structure of a piezoelectric resonant pressure sensor provided as an example of the present application, which is not provided with lead electrodes and a protective layer, and the structure is provided with four lead bridges.

[0043] Fig.13 A schematic diagram of the structure of a piezoelectric resonant pressure sensor provided as an example of the present application, which is not provided with lead electrodes and a protective layer, and the structure is provided with three lead bridges.

[0044] Fig.14 A schematic diagram of the structure of a piezoelectric resonant pressure sensor provided as an example of the present application, which is not provided with lead electrodes and a protective layer, and the structure is provided with two lead bridges.

[0045] Fig.15 A schematic diagram of the structure of a piezoelectric resonant pressure sensor provided as an example of the present application, which is not provided with lead electrodes and a protective layer, and the structure is provided with a lead bridge.

[0046] Fig.16 A schematic diagram of the structure of a piezoelectric resonant pressure sensor provided as an example of the present application, which is not provided with lead electrodes and a protective layer, and the structure is not provided with a lead bridge.

[0047] Fig.17 A schematic diagram of the structure of another piezoelectric resonant pressure sensor provided as an example in this application.

[0048] Fig.18 A schematic diagram of the structure of a compensation system provided for the example of this application.

[0049] Fig.19 A schematic diagram of the working process of a compensation system provided as an example of this application.

[0050] Description of reference numerals:

[0051] 100. Piezoelectric resonant pressure sensor; 110. Piezoelectric component; 111. First lead electrode; 112. Second lead electrode; 113. First electrode; 114. Piezoelectric layer; 115. Second electrode; 120. Resonant layer; 121. Resonant film; 122. First connecting part; 123. Second connecting part; 130. Pressure resonance component; 131. Resonant cavity; 132. Pressure cavity; 133. Pressure sensitive film; 134. Connecting structure; 135. Resonant base; 136. Resonant substrate; 140. Oxide layer; 150. Protective layer; 160. Cover; 170. Groove; 171. Lead bridge; 172. Beam structure; 200. Compensation system; 210. Pressure sensor; 220. Compensation sensor; 230. Driving component; 240. Detection component. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical solution and advantages of the examples of this application clearer, the technical solution in the examples of this application will be clearly and completely described below in conjunction with the drawings in the examples of this application. Obviously, the described examples are part of the examples of this application, not all of them. Based on the examples in this application, all other examples obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0053] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of the application herein are only for the purpose of describing specific examples and are not intended to limit this application; the terms "including" and "having" in the specification, claims and drawings of this application and any variations thereof are intended to cover non-exclusive inclusions.

[0054] Reference to "examples" herein means that a particular feature, structure, or characteristic described in conjunction with the examples may be included in at least one example of the present application. The appearance of the phrase "example" in various locations in the specification does not necessarily refer to the same example, nor is it an independent or alternative example that is mutually exclusive with other examples. It is explicitly and implicitly understood by those skilled in the art that the examples described herein may be combined with other examples.

[0055] The term "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0056] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of the piezoelectric resonant pressure sensor of the present application.

[0057] In addition, the terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects rather than to describe a specific order, and may explicitly or implicitly include one or more of the features.

[0058] In the description of the present application, unless otherwise specified, "plurality" means more than two (including two), and similarly, "multiple groups" means more than two groups (including two).

[0059] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, the "connection" or "connection" of a mechanical structure may refer to a physical connection. For example, the physical connection may be a fixed connection, such as a fixed connection through a barrier, such as a fixed connection through screws, bolts or other barrier; the physical connection may also be a detachable connection, such as a mutual snap-on or snap-fit ​​connection; the physical connection may also be an integral connection, such as a connection formed by welding, bonding or integral molding. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0060] 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 accuracy and good stability. It is suitable for scenes with high accuracy requirements and harsh environments such as aerospace, oil and gas exploration, etc. 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, optical drive-optical detection type resonant pressure sensors, and quartz material resonant pressure sensors. The measurement structure can be a detection circuit or other structure that can detect the pressure to be detected.

[0061] Among them, the processing technology of the electrostatic excitation-resistance detection type resonant pressure sensor is relatively simple, but because the 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 consistency of the piezoresistors makes the processing requirements of the electrostatic excitation-resistance detection type resonant pressure sensor relatively high.

[0062] 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 of the varistor.

[0063] The electromagnetic drive-electromagnetic detection type resonant pressure sensor uses the time-varying Lorentz force of the resonator in the excitation electromagnetic field to produce periodic vibrations, and then uses the inverse process of electromagnetic drive to detect the vibration. Due to the need for electromagnetic fields, this method requires additional sensor peripherals to provide magnetic fields, and the sensor is not easy to miniaturize.

[0064] Based on the above, the present application example provides a piezoelectric resonant pressure sensor and compensation system.

[0065] The piezoelectric resonant pressure sensor mentioned in the example of this application can be combined with MEMS technology to achieve mass production of piezoelectric resonant pressure sensors and improve the production efficiency of piezoelectric resonant pressure sensors.

[0066] The piezoelectric resonant pressure sensor mentioned in the example of this application can output a corresponding electrical signal based on the received pressure to be detected, and is a sensitive element.

[0067] In order to enable those skilled in the art to better understand the present application, the piezoelectric resonant pressure sensor and compensation system provided in the example of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0068] For example, Figure 1 A schematic diagram of the structure of a piezoelectric resonant pressure sensor provided as an example of this application, Figure 2 A top view of a schematic diagram of the structure of a piezoelectric resonant pressure sensor provided as an example of this application, Figure 3 for Figure 2 The cross-sectional view of AA in the figure, Figure 4 for Figure 2 For the cross-sectional view of BB, please refer to Figure 1 to Figure 4 The piezoelectric resonance pressure sensor 100 includes a piezoelectric component 110 , a resonance film 121 and a pressure resonance component 130 .

[0069] The piezoelectric component 110 is directly or indirectly connected to an external circuit. The resonant film 121 is disposed on one side of the piezoelectric component 110, and the resonant film 121 is directly or indirectly connected to the piezoelectric component 110. The pressure resonance component 130 is disposed on one side of the resonant film 121 and is connected to the resonant film 121. A resonant groove is disposed on the side of the pressure resonance component 130 facing the resonant film 121. The resonant film 121 is disposed at the opening of the resonant groove, and the resonant groove and the resonant film 121 cooperate to form a resonant cavity 131. A pressure cavity 132 is disposed on the side of the pressure resonance component 130 away from the resonant film 121. A pressure sensitive film 133 is disposed between the resonant groove and the pressure cavity 132. The pressure cavity 132 is used to receive the pressure to be detected. In the direction from the resonant film 121 to the pressure resonance component 130, the projection of the resonant cavity 131 at least partially falls within the projection range of the pressure cavity 132.

[0070] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the pressure chamber 132 can receive the pressure to be detected. Since the pressure chamber 132 is arranged on the side of the pressure resonance component 130 away from the resonance film 121, and the pressure resonance component 130 is directly or indirectly connected to the resonance film 121, the pressure to be detected can be transmitted to the resonance film 121 through the pressure resonance component 130. Since the resonance film 121 is arranged on one side of the piezoelectric component 110, the resonance film 121 is directly or indirectly connected to the piezoelectric component 110, and the pressure to be detected indirectly acting on the resonance film 121 can be transmitted to the piezoelectric component 110.

[0071] Next, the structure of the piezoelectric resonant pressure sensor 100 is described in detail.

[0072] A resonance groove may be provided on the pressure resonance component 130 . A pressure sensitive film 133 may be formed on the side of the pressure resonance component 130 away from the opening of the resonance groove. The side of the pressure sensitive film 133 away from the resonance groove may be a pressure chamber 132 .

[0073] The pressure resonance component 130 may also be provided with a resonance groove and other connection structures, and a pressure sensitive film 133 may be formed on the side of the pressure resonance component 130 away from the opening of the resonance groove, and the pressure sensitive film 133 may cooperate with other connection structures to form a pressure chamber 132. The example of this application does not limit the specific implementation of the pressure chamber 132.

[0074] The pressure to be detected received by the pressure chamber 132 may be the pressure applied directly or indirectly by the fluid to the pressure resonance component 130 , and the fluid may be liquid, gas, etc.

[0075] The resonant film 121 can be directly or indirectly connected to the side of the pressure resonance component 130 away from the pressure chamber 132, and the resonant film 121 is arranged at the opening of the resonant groove. The resonant film 121 can close the opening of the resonant groove. The resonant film 121 can also be provided with a through hole that does not close the opening of the resonant groove. The resonant film 121 cooperates with the resonant groove to form a resonant cavity 131.

[0076] A piezoelectric component 110 is arranged on the side of the resonant film 121 facing away from the pressure resonance component 130. The pressure to be detected acting on the pressure resonance component 130 can indirectly act on the piezoelectric component 110 through the pressure resonance component 130 and the resonant film 121, and the pressure to be detected is detected by the piezoelectric component 110.

[0077] Exemplarily, the piezoelectric component 110 may include a piezoelectric layer 114 and electrodes, and 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, the two opposite sides of the piezoelectric layer 114 can generate a potential difference. By using the positive piezoelectric effect and the inverse piezoelectric effect of the piezoelectric layer 114, the vibration of the piezoelectric resonant pressure sensor 100 can be detected, and then the relevant parameters of the pressure to be detected can be obtained. The relevant parameters may include the numerical value of the pressure to be detected and the direction parameters of the pressure to be detected.

[0078] 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.

[0079] 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.

[0080] The resonant film 121 may be directly or indirectly connected to a side of the pressure resonance component 130 away from the pressure cavity 132 , and the resonant film 121 may be disposed at the opening of the resonant groove. The resonant film 121 cooperates with the resonant groove to form a resonant cavity 131 .

[0081] Along the direction from the resonant film 121 to the pressure resonance component 130 , the projection of the resonant cavity 131 at least partially falls within the projection range of the pressure cavity 132 .

[0082] The projection of the resonance cavity 131 can completely fall within the projection range of the pressure cavity 132 . At this time, the geometric center of the resonance groove projection can overlap with the geometric center of the pressure cavity 132 projection, and there may also be a distance between the geometric center of the resonance groove and the geometric center of the pressure cavity 132 .

[0083] Part of the projection of the resonance cavity 131 may also fall within the projection range of the pressure cavity 132 , that is, the projection of the resonance cavity 131 partially overlaps with the projection of the pressure cavity 132 .

[0084] The shape of the pressure chamber 132 may be the same as the shape of the resonance groove, or the shape of the pressure chamber 132 may be different from the shape of the resonance groove. The present application example is described here only by taking the pressure chamber 132 as an example. For example, the shape of the pressure chamber 132 may be cylindrical, the shape of the pressure chamber 132 may be prismatic, or the shape of the pressure chamber 132 may be irregular.

[0085] There may be one pressure chamber 132, or there may be multiple pressure chambers 132 spaced apart. There may be only one resonance groove, or there may be multiple resonance grooves, which is not limited in the present application example.

[0086] The example of the present application does not specifically limit the positional relationship between the resonance groove and the pressure chamber 132, as long as it is ensured that the projection of at least part of the resonance cavity 131 coincides with the projection of the pressure chamber 132, thereby ensuring that the pressure to be detected received by the pressure chamber 132 can be transmitted to the piezoelectric component 110 through the resonance groove, and the pressure to be detected can be detected by the piezoelectric component 110.

[0087] Based on the above, according to the piezoelectric resonant pressure sensor 100 provided in the example of the present application, the pressure chamber 132 can receive the pressure to be detected, and the pressure to be detected can be transmitted to the piezoelectric component 110 and the resonant film 121 through the pressure resonance 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 film 121 away from the pressure resonance component 130, the piezoelectric component 110 is spaced apart from the pressure chamber 132 that receives the pressure to be detected. And since the resonant groove on the pressure resonance component 130 cooperates with the resonant film 121 to form the resonant cavity 131. In the case where the piezoelectric component 110 drives the pressure resonance component 130 to vibrate, the resonant cavity 131 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.

[0088] 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.

[0089] In addition, in the example of the present application, since the projection of the resonance cavity 131 at least partially falls within the projection range of the pressure cavity 132 along the direction from the resonance film 121 to the pressure resonance component 130, that is, the resonance cavity 131 at least partially overlaps with the pressure cavity 132. 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 100 and the integrated development of the piezoelectric resonant pressure sensor 100.

[0090] Based on the piezoelectric resonance pressure sensor 100 provided in the above example, along the direction from the resonance film 121 to the pressure resonance component 130 , the projection of the resonance cavity 131 falls within the projection range of the pressure cavity 132 .

[0091] By following the direction from the resonance cavity 131 to the pressure cavity 132, the projection of the resonance cavity 131 can completely fall within the projection range of the pressure cavity 132. In this way, the volume of the piezoelectric resonant pressure sensor 100 can be further 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.

[0092] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, please refer to Figure 4 At least a portion of the oxide layer 140 is disposed at the connection between the resonant film 121 and the pressure resonance component 130 .

[0093] The oxide layer 140 can be used to connect the resonance film 121 and the pressure resonance component 130. The oxide layer 140 can be a connection component formed during the connection process between the resonance film 121 and the pressure resonance component 130. The oxide layer 140 can also be a connection component deliberately provided between the resonance film 121 and the pressure resonance component 130.

[0094] The resonant film 121 and the pressure resonance component 130 can be made of silicon or other semiconductor materials. The oxide layer 140 can be made of silicon oxide or other materials. The manufacturing material of the oxide layer 140 can be different based on the different manufacturing materials of the resonant film 121 and the pressure resonance component 130. The specific setting of the oxide layer 140 is not limited in the example of this application.

[0095] The present application example is described by taking the case where the resonant film 121 and the pressure resonant component 130 are both made of silicon material and the oxide layer 140 is made of silicon oxide material. Compared with silicon material, silicon oxide material has better insulation and lower thermal conductivity.

[0096] In summary, the oxide layer 140 can ensure the insulation between the resonant film 121 and the pressure resonance component 130 , thereby ensuring the reliability of the piezoelectric resonant pressure sensor 100 .

[0097] The oxide layer 140 can also reduce the influence of temperature in environmental factors on the piezoelectric resonant pressure sensor 100 , thereby ensuring the measurement accuracy of the resonant pressure sensor.

[0098] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the resonant film 121 is bonded to the pressure resonance component 130 , and at least a portion of the oxide layer 140 is formed at the bonding location between the resonant film 121 and the pressure resonance component 130 .

[0099] The resonant film 121 and the pressure resonance component 130 can be connected together by anodic bonding, melt bonding or other bonding methods. The oxide layer 140 formed at the bonding connection between the resonant film 121 and the pressure resonance component 130 can ensure the connection reliability between the resonant film 121 and the pressure resonance component 130, thereby ensuring the reliability of the piezoelectric resonant pressure sensor 100.

[0100] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the resonant film 121 is processed from an SOI wafer, the pressure resonance component 130 is processed from an Si wafer, the device layer of the SOI wafer is bonded to the Si wafer, and at least a partial oxide layer 140 is formed at the connection position between the SOI wafer and the Si wafer.

[0101] The SOI wafer may include a device layer, a buried oxide layer, and a substrate layer, wherein the thickness of the device layer may be equal to the thickness of the resonant film 121, or the thickness of the device layer may be less than the thickness of the resonant film 121, as long as the resonant film 121 is processed based on the SOI wafer. The resonant film 121 may include only the device layer, or the resonant film 121 may include the device layer and at least part of the buried oxide layer, or the resonant film 121 may include the device layer, the buried oxide layer, and at least part of the substrate layer. The example of the present application does not limit the specific implementation of the resonant film 121.

[0102] Relative to the entire SOI wafer, the device layer is disposed close to the Si wafer. Therefore, when the SOI wafer and the Si wafer are bonded, the bonding position between the SOI wafer and the Si wafer is between the device layer and the Si wafer.

[0103] The bonding connection method is similar to the bonding connection method described above and plays a similar role, so the example of this application will not be repeated here.

[0104] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, Figure 5 A schematic diagram of the structure of another piezoelectric resonant pressure sensor provided as an example of this application, Figure 6 A top view of another piezoelectric resonant pressure sensor structure schematic diagram provided for the example of this application, Figure 7 for Figure 6 Middle CC section view, Figure 8 for Figure 7 For the partial enlarged view of point A in the middle, please refer to Figures 5 to 8 The pressure resonance component 130 may include at least one connection structure 134, which is disposed on a side of the pressure resonance component 130 facing the pressure sensitive film 133, and the at least one connection structure 134 cooperates with the pressure sensitive film 133 to form a resonance groove.

[0105] The connection structure 134 may be cylindrical, prism-shaped, truncated cone-shaped or other shapes. At least one connection structure 134 may be provided, or two, three, or even more connection structures 134 may be provided.

[0106] The connection structure 134 can be an integrated structure with the pressure sensitive film 133. In this case, the resonance groove can be a groove formed by removing the middle part of a block structure. The pressure sensitive film 133 can be a partial block structure corresponding to the bottom wall of the resonance groove. The connection structure 134 can be a partial block structure corresponding to the side wall of the resonance groove.

[0107] The connection structure 134 can also be connected to the pressure sensitive film 133 by bonding or other connection methods. In this case, the connection structure 134 can include multiple ones, and different connection structures 134 can be connected to the side walls of the corresponding pressure sensitive film 133. In this case, the pressure sensitive film 133 can serve as the bottom wall of the resonance groove, and the connection structure 134 can serve as the side wall of the resonance groove. The pressure sensitive film 133 and the connection structure 134 together enclose the resonance groove.

[0108] At least one first connection portion 122 may be provided on the peripheral side of the resonant film 121, and the at least one first connection portion 122 may be provided between the piezoelectric component 110 and the connection structure 134, and the first connection portion 122 may connect the piezoelectric component 110 and the connection structure 134. Therefore, the connection structure 134 may be connected to the piezoelectric component 110 through the first connection portion 122.

[0109] At least one first connection part 122 and the resonance film 121 can cooperate to form a resonance layer 120. The resonance layer 120 can also include other components, such as a second connection part 123. The specific structure of the second connection part 123 is described below.

[0110] Based on the above, since the pressure sensitive film 133 is provided on one side of the connection structure 134, the other side of the connection structure 134 is directly or indirectly connected to the piezoelectric component 110. Based on this, the pressure to be detected acting on the pressure sensitive film 133 can be transmitted to the resonant film 121 and the piezoelectric component 110 through the connection structure 134, generating stress in the resonant film 121 and the piezoelectric component 110, thereby causing a change in the vibration frequency of the resonant film 121 and the piezoelectric component 110. Since the resonant cavity 131 is provided on one side of the piezoelectric component 110, the resonant cavity 131 can provide a vibration space for the vibration of the piezoelectric component 110, thereby reducing the possibility of the piezoelectric component 110 being damaged due to deformation of the piezoelectric component 110 due to vibration.

[0111] Fig. 9 A schematic diagram of the working principle of a piezoelectric resonant pressure sensor provided in this application example, referring to Fig. 9 , the connection structure 134 can change the direction of action of the pressure to be detected.

[0112] Exemplarily, the pressure to be detected acts on the pressure sensitive film 133 in a direction perpendicular to the pressure sensitive film 133. The pressure to be detected acting on the pressure sensitive film 133 can be transmitted to the resonant film 121 through the connecting structure 134. The connecting structure 134 can convert the pressure to be detected perpendicular to the pressure sensitive film 133 into a working stress having an angle between the direction of action and the direction of action of the pressure to be detected.

[0113] In summary, the resonant cavity 131 can provide a vibration space for the vibration of the piezoelectric component 110, reducing the possibility of damage to the piezoelectric component 110 due to deformation of the piezoelectric component 110 caused by vibration. The connecting structure 134 can directly or indirectly connect the pressure sensitive film 133 and the piezoelectric component 110, and the connecting structure 134 can change the direction of action of the pressure to be detected, so that the pressure to be detected acting vertically on the piezoelectric component 110 is smaller, reducing the possibility of damage to the piezoelectric component 110, improving the pressure bearing capacity of the resonant film 121, 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.

[0114] In the piezoelectric resonant pressure sensor 100 mentioned in the above example, the cavity can be kept in vacuum, or the cavity can be filled with a medium.

[0115] Exemplarily, the piezoelectric resonant pressure sensor 100 may be an absolute pressure sensor. The absolute pressure sensor is used to measure absolute pressure and can convert the absolute pressure of gas or liquid into an equivalent electrical signal output.

[0116] Exemplarily, the piezoelectric resonant pressure sensor 100 may be a relative pressure sensor. The relative pressure sensor is measured based on the atmospheric pressure, so the measurement result of the relative pressure sensor is relative to the atmospheric pressure. Therefore, the relative pressure sensor can be used to measure the difference in relative pressure.

[0117] The user can select a suitable absolute pressure sensor or relative pressure sensor according to the requirements. The present application example does not limit whether a medium is injected into the resonance cavity 131 .

[0118] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the side of the connecting structure 134 close to the pressure sensitive film can be an anchor point, the distance between the anchor point and the resonant film 121 is a first distance, and the distance between the anchor point and the pressure sensitive film is a second distance, and the first distance is greater than the second distance.

[0119] The anchor point is the main stress point of the connection structure 134 .

[0120] By setting the first distance to be greater than the second distance, the resonant film 121, the pressure sensitive film and the anchor point can work 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 134 with the 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.

[0121] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the pressure resonance component 130 also includes at least one resonant substrate 136, which is arranged on the side of the pressure resonance component 130 away from the resonant film 121, and the at least one resonant substrate 136 cooperates with the pressure sensitive film 133 to form a pressure chamber 132.

[0122] The resonant substrate 136 may be an integrated structure with the pressure sensitive film 133. In this case, the pressure cavity 132 may be a cavity formed by removing the middle portion of a block structure. The pressure sensitive film 133 may be a portion of the block structure corresponding to the cavity bottom of the pressure cavity 132. The resonant substrate 136 may be a portion of the block structure corresponding to the side wall of the pressure cavity 132.

[0123] The resonant substrate 136 may also be connected to the pressure sensitive film 133 by bonding or other means. In this case, the resonant substrate 136 may include multiple resonant substrates, and different resonant substrates 136 may be connected to the side walls of the corresponding resonant film 121. In this case, the pressure sensitive film 133 may serve as the bottom wall of the pressure cavity 132, and the resonant substrate 136 may serve as the side wall of the pressure cavity 132. The pressure sensitive film 133 and the resonant substrate 136 together enclose the pressure cavity 132.

[0124] By setting up a resonant substrate 136, the resonant substrate 136 cooperates with the pressure sensitive film 133 to form a pressure chamber 132. The operator can control the gas or liquid or other fluid to apply pressure to the cavity wall of the pressure chamber 132. By setting up the pressure chamber 132, the force on the pressure sensitive film 133 can be more concentrated, which is convenient for the operator to apply the pressure to be detected to the cavity wall of the pressure chamber 132.

[0125] In the example of the present application, the resonant substrate 136 , the connecting structure 134 , the pressure sensitive film 133 and other structures of the pressure resonance component 130 can be integrally formed, so that the processing technology of the piezoelectric resonant pressure sensor 100 can be reduced and the processing cost of the piezoelectric resonant pressure sensor 100 can be reduced.

[0126] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, Fig.10 A schematic diagram of the resonance principle of a piezoelectric resonant pressure sensor provided for this application example, please refer to Figure 1 to Figure 6 as well as Fig.10 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 .

[0127] The second electrode 115 may be disposed on a side of the resonant film 121 away from the pressure resonance component 130, and a side of the second electrode 115 facing the resonant film 121 may be directly or indirectly connected to the resonant film 121. The piezoelectric layer 114 may be disposed on a side of the second electrode 115 away from the resonant film 121, and a 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 a side of the piezoelectric layer 114 away from the second electrode 115, and a side of the piezoelectric layer 114 facing the first electrode 113 may be connected to the first electrode 113.

[0128] The first lead electrode 111 is disposed on a side of the first electrode 113 away from the piezoelectric layer 114 , one end of the first lead electrode 111 may be connected to the first electrode 113 , and the other end of the first lead electrode 111 may be connected to a first portion of an external circuit.

[0129] The second lead electrode 112 is disposed on a side of the second electrode 115 facing the piezoelectric layer 114 , one end of the second lead electrode 112 may be connected to the second electrode 115 , and the other end of the second lead electrode 112 may be connected to a second portion of the external circuit.

[0130] The first electrode 113, the second electrode 115, the first lead electrode 111, and the second lead electrode 112 may all be made of a conductive material, such as aluminum, copper, or gold. The number of the first lead electrodes 111 may correspond to the number of the first electrodes 113, at least one second lead electrode 112 may be provided, or a plurality of second lead electrodes 112 may be provided, and the plurality of second lead electrodes 112 may be connected to different positions of the second electrode 115.

[0131] The shapes of the first electrode 113 and the second electrode 115 may be the same or different. This application example only takes the first electrode 113 as an example for description. For example, the first electrode 113 may be cylindrical, prism or any other regular shape, or may be irregular.

[0132] The shapes of the first lead electrode 111 and the second lead electrode 112 may be the same or different. Here, only the first lead electrode 111 is taken as an example for description.

[0133] Exemplarily, the first lead electrode 111 may include a first portion and a second portion connected to each other, one end of the first portion is connected to the first electrode 113, and one end of the second portion is connected to an external circuit. The cross-sectional shapes of the first portion and the second portion may be the same or different, for example, the cross-sectional shape of the first portion may be circular, elliptical, polygonal or irregular. This application example does not limit the specific implementation of the first electrode 113, the second electrode 115, the first lead electrode 111 and the second lead electrode 112.

[0134] The second electrode 115 may be a conductive layer laid on the side of the resonance film 121 away from the resonance groove, and only one second electrode 115 may be provided. The second electrode 115 may be used to achieve grounding of the piezoelectric resonance pressure sensor 100 .

[0135] A piezoelectric layer 114 may be provided on a side of the second electrode 115 facing away from the resonance film 121 .

[0136] The first electrode 113 may be disposed on a side of the piezoelectric layer 114 away from the second electrode 115, and at least two first electrodes 113 may be provided. The first electrode 113 may 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.

[0137] The external circuit may be a detection circuit for detecting an output electrical signal of the piezoelectric resonant pressure sensor 100. The first portion of the external circuit may be an input portion of the external circuit, and the second portion of the external circuit may be an output portion of the external circuit. The example of the present application does not limit the first portion and the second portion of the external circuit, as long as the connection between the piezoelectric resonant pressure sensor 100 and the external circuit can be achieved.

[0138] Next, please refer to Fig. 9 and Fig.10 , the principle of the piezoelectric resonant pressure sensor 100 is further introduced in combination with the specific structure of the piezoelectric component 110.

[0139] The resonant film 121 , the resonant cavity 131 , the connecting structure 134 and the piezoelectric component 110 cooperate with each other to form a piezoelectric resonator. The piezoelectric resonator may also include other structures.

[0140] When any of the first electrodes 113 receives a voltage, stress is generated in the piezoelectric layer 114 based on the inverse piezoelectric effect of 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 drives the entire piezoelectric resonator to deform.

[0141] When an alternating voltage having the same resonant frequency as the piezoelectric resonator is applied to any first electrode 113, the entire structure will resonate, and the resonant frequency is:

[0142]

[0143] In the formula, f r is the resonant frequency, μ n are the constants 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.

[0144] When the pressure chamber 132 receives the pressure to be detected, the pressure sensitive film 133 will be deformed and generate working stress under the action of the pressure to be detected. The connection structure 134 can transfer the deformation and working stress of the pressure sensitive film 133 to the piezoelectric resonator, specifically to the piezoelectric layer 114. During the transmission process of the connection structure 134, the connection structure 134 can change the direction of action of the pressure to be detected, reducing the possibility of damage to the resonant film 121. The anchor point can use the lever principle to amplify the working stress and increase the measurement range of the piezoelectric resonant pressure sensor 100.

[0145] 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 detects the vibration of the piezoelectric resonator. The first electrode 113 receiving the voltage may be a driving electrode, and the first electrode 113 detecting the vibration may be a detecting electrode.

[0146] Due to the positive piezoelectric effect of the piezoelectric film material, the detection electrode will generate an electrical signal, which can be used to detect the resonant frequency of the piezoelectric resonator.

[0147] Assume that the working stress generated by the pressure to be detected on the piezoelectric resonator is σ, and the resonant frequency of the piezoelectric resonator is:

[0148]

[0149] From the above formula, it can be seen that the pressure value can be determined when the frequency change of the piezoelectric resonator is detected.

[0150] When the piezoelectric layer 114 is deformed, the part of the piezoelectric layer 114 close to the resonance film 121 is squeezed by the pressure to be detected, and the part of the piezoelectric layer 114 away from the resonance film 121 is stretched by the pressure to be detected. On the cross section of the piezoelectric layer 114, the transition layer between the stretched part of the piezoelectric layer 114 and the squeezed part of the piezoelectric layer 114, which is neither stretched nor compressed and has almost zero stress, is the above-mentioned neutral layer.

[0151] 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 100 provided in the example of the present application does not require the setting of an additional detection circuit, has a simpler structure, and has a lower manufacturing cost.

[0152] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, Fig.11 A schematic diagram of the internal structure of a piezoelectric resonant pressure sensor provided as an example in this application. Figure 3 , Figure 7 as well as Fig.11 Schematic diagrams of the internal structure of piezoelectric resonant pressure sensors 100 of different structures are respectively used to represent the internal structure of piezoelectric resonant pressure sensors 100 of different structures. Figure 3 It is used to illustrate the internal structure of the piezoelectric resonant pressure sensor 100 when the piezoelectric resonant pressure sensor 100 is not provided with a groove. Figure 7 It is used to illustrate the internal structure of the piezoelectric resonant pressure sensor 100 when the piezoelectric resonant pressure sensor 100 is provided with a groove. Fig.11 It is used to illustrate the internal structure of the piezoelectric resonant pressure sensor 100 when the piezoelectric resonant pressure sensor 100 is provided with another type of groove.

[0153] Please refer to Figure 7 or Fig.11 At least one groove 170 is provided on the piezoelectric resonant pressure sensor 100. The groove 170 can be provided between the resonant film 121 and the pressure sensitive film 133. Alternatively, the groove 170 can also be provided on the side of the resonant film 121 away from the resonant substrate 136, and the opening of the groove 170 is opened away from the resonant substrate 136.

[0154] For example, please refer to Fig.11 The resonant film 121 may further include a resonant substrate 135 , and the resonant substrate 135 is disposed on a side of the pressure resonance component 130 away from the pressure chamber 132 . The resonant substrate 135 may be connected to the piezoelectric layer through the second connecting portion 123 .

[0155] A portion of the oxide layer may be located between the second connection portion 123 and the resonance substrate 135 to ensure connection reliability between the second connection portion 123 and the resonance substrate 135 .

[0156] The groove 170 may be disposed between the resonance film 121 and the pressure sensitive film 133 along the direction from the resonance film 121 toward the pressure resonance component 130. The groove 170 may be disposed between the resonance base 135 and the connection structure 134 along the cross-section of the resonance groove.

[0157] The groove 170 can keep a distance between the resonant substrate 135 and the connecting structure 134 , thereby reducing the cross-sectional area of ​​the connecting structure 134 , so that the working stress transmitted to the pressure sensitive film 133 through the connecting structure 134 is more concentrated, which is beneficial to improving the detection accuracy of the piezoelectric resonant pressure sensor 100 .

[0158] For example, please refer to Figure 7 The resonant film 121 may further include a resonant substrate 135 . The configuration of the resonant substrate 135 is similar to that of the resonant substrate 135 mentioned in the above example, and the present application example will not be described in detail here.

[0159] The groove 170 may also be provided on a side of the resonance film 121 away from the resonance substrate 136 , and an opening of the groove 170 is opened away from the resonance substrate 136 .

[0160] The groove 170 mentioned in the example of the present application can keep a distance between the resonant substrate 135 and the connecting structure 134, thereby reducing the cross-sectional area of ​​the connecting structure 134, so that the working stress transmitted to the pressure sensitive film 133 through the connecting structure 134 is more concentrated, which is beneficial to improving the detection accuracy of the piezoelectric resonant pressure sensor 100.

[0161] In addition, since the opening of the groove 170 mentioned in the example of the present application is opened away from the resonant substrate 136, the opening 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 away from the resonant film 121. Based on this, the resonant film 121 can divide the piezoelectric layer 114 into at least two parts, and along the direction from the resonant groove to the pressure cavity 132, the projection of the groove 170 is located between the projection of at least one lead electrode and the projection of the resonant cavity 131, 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, and 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, and the possibility of the lead electrode vibrating under the action of the pressure to be detected can be reduced, thereby ensuring the reliability of the piezoelectric resonant pressure sensor 100.

[0162] By providing the grooves 170 , a lead bridge 171 may be formed between two adjacent grooves 170 . The lead bridge 171 may be in a cross shape, a 'M' shape, a straight shape or other irregular shapes.

[0163] The number of lead bridges 171 may be equal to and correspond to the number of first lead electrodes 111, or the number of lead bridges 171 may be less than the number of first lead bridges 171, which is not limited in this example of the present application. Figure 12 to Figure 16 , Fig.12 A schematic diagram of the structure of a piezoelectric resonant pressure sensor provided as an example of the present application, which is not provided with lead electrodes and a protective layer, and the structure is provided with four lead bridges. Fig.13 A schematic diagram of the structure of a piezoelectric resonant pressure sensor provided as an example of the present application, which is not provided with lead electrodes and a protective layer, and the structure is provided with three lead bridges. Fig.14 A schematic diagram of the structure of a piezoelectric resonant pressure sensor provided as an example of the present application, which is not provided with lead electrodes and a protective layer, and the structure is provided with two lead bridges. Fig.15 A schematic diagram of the structure of a piezoelectric resonant pressure sensor provided as an example of the present application, which is not provided with lead electrodes and a protective layer, and the structure is provided with a lead bridge. Fig.16 A schematic diagram of the structure of a piezoelectric resonant pressure sensor provided as an example of the present application, which is not provided with lead electrodes and a protective layer, and the structure is not provided with a lead bridge.

[0164] The lead bridge 171 can provide a location for the lead connecting the first lead electrode 111 and the first electrode 113 , and adjust the location of the first lead electrode 111 to ensure the connection reliability between the first lead electrode 111 and the first electrode 113 .

[0165] Please refer to Fig.12A beam structure 172 may be provided at the location where the first electrode 113 is provided, and one or more beam structures 172 may be provided. The multiple beam structures 172 may be in a cross shape, a M-shaped shape, a straight shape, or other irregular shapes.

[0166] An angle may be formed between the beam structure 172 and the lead bridge 171 .

[0167] 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 in a straight line shape, and the connection electrode can be provided on the lead bridge 171 to realize 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 and lead bridges 171 is equal, the beam structure 172 and the lead bridge 171 can cooperate to form a straight-line structure, a cross-shaped structure, a cross-shaped structure, or other structures.

[0168] Exemplarily, the angle between the beam structure 172 and the lead bridge 171 may 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 broken line shape. In this case, the number of beam structures 172 may be equal to or different from the number of lead bridges 171. This application example does not limit the specific implementation of the beam structure 172 and the lead bridge 171.

[0169] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the piezoelectric component 110 may further include a seed layer, which is disposed between the piezoelectric component 110 and the resonant film 121 , and specifically between the second electrode 115 and the resonant film 121 .

[0170] By providing the seed layer, the working performance of the piezoelectric component 110 can be guaranteed, and further the working performance of the piezoelectric resonant pressure sensor 100 can be guaranteed.

[0171] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, Fig.17 For a schematic diagram of another piezoelectric resonant pressure sensor provided in this application example, please refer to Fig.17 The piezoelectric resonant pressure sensor 100 may further include a cover 160 . The cover 160 is disposed on a side of the resonant film 121 away from the pressure resonance component 130 . The cover 160 is directly or indirectly connected to the resonant film 121 .

[0172] The cover 160 may be made of a silicon wafer, a glass wafer, an inorganic semiconductor material, or other amorphous inorganic non-metallic materials.

[0173] In a vacuum environment, the cover 160 can be used to encapsulate the piezoelectric resonator. The cover 160 can be set on the side of the piezoelectric component 110 away from the resonant film 121 to isolate the piezoelectric component 110 from the atmospheric environment, ensure that the piezoelectric component 110 is in a vacuum environment when working, and then improve the value corresponding to the quality factor of the piezoelectric resonant pressure sensor 100, and ensure the working performance of the piezoelectric resonant pressure sensor 100.

[0174] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, please refer to Figure 4 A protective layer 150 may be provided on the side of the piezoelectric component 110 facing away from the resonance film 121 . The protective layer 150 may be made of silicon dioxide material or other moisture-proof material.

[0175] The protective layer 150 can isolate the piezoelectric component 110 from the atmospheric environment, and the protective layer 150 can play a role in moisture-proofing, so that the piezoelectric resonant pressure sensor 100 is kept in a dry state as much as possible, ensuring the working reliability of the piezoelectric resonant pressure sensor 100. The protective layer 150 can also play a role in temperature compensation during the operation of the piezoelectric resonant pressure sensor 100.

[0176] During the use of the piezoelectric resonant pressure sensor 100, only the cover 160 may be provided, only the protective layer 150 may be provided, both the cover 160 and the protective layer 150 may be provided, or neither the cover 160 nor the protective layer 150 may be provided. This application example does not impose any specific limitation on this.

[0177] 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.

[0178] Exemplarily, the present application provides a compensation system 200, Fig.18 A schematic diagram of a compensation system 200 provided in this application example is provided in FIG. Fig.18 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.

[0179] 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.

[0180] In the case where only one compensation sensor 220 is provided, only one detection sensor may be provided, or a plurality of detection sensors may be provided.

[0181] 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.

[0182] 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, and 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 resonant frequency of the pressure sensor 210 and the compensation sensor 220.

[0183] Since the pressure sensor 210 and the compensation sensor 220 are integrated together and have the same resonant film 121, environmental factors such as temperature, vibration, and impact will have the same impact on the resonant film 121 of the pressure sensor 210 and the compensation sensor 220, so that the resonant film 121 of the pressure sensor 210 and the compensation sensor 220 can have the same output based on the influence of environmental factors.

[0184] Based on this, when the detection component 240 detects the resonant frequency of the pressure sensor 210 and the compensation sensor 220, it only needs to subtract the resonant frequency output by the compensation sensor 220 from the resonant frequency output by the pressure sensor 210 and then extract the final resonant frequency, thereby eliminating the influence of environmental factors and improving the detection accuracy of the compensation system 200 for the pressure to be detected.

[0185] Fig.19 For a schematic diagram of the working process of a compensation system 200 provided as an example of this application, please refer to Fig.19 , the working process of the compensation sensor 220 is as follows:

[0186] S101 , the driving component 230 is used to drive the pressure sensor 210 and the compensation sensor 220 .

[0187] S102 , the detection component 240 is used to detect and output a first resonant frequency corresponding to the pressure sensor 210 and a second resonant frequency corresponding to the compensation sensor 220 .

[0188] S103, a calculation module is used to calculate the difference between the first resonant frequency and the second resonant frequency to obtain a target resonant frequency.

[0189] S104, the calculation module may also calculate the pressure value of the pressure to be detected based on the resonance frequency.

[0190] The calculation module may be a part of the detection component 240 , or a module independent of the detection component 240 , which is not limited in this example of the present application.

[0191] 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 132 of the pressure sensor, and the pressure to be detected does not act on the compensation sensor 220. Based on this, the structure of the pressure sensor 210 and the structure of the compensation sensor 220 can be completely consistent. The structures of the pressure sensor 210 and the compensation sensor 220 may also be inconsistent, for example, the compensation sensor 220 may not be provided with the pressure resonance component 130. The example of this application does not limit the specific structures of the pressure sensor 210 and the compensation sensor 220.

[0192] In summary, according to the compensation system 200 provided in the example of the present application, when the detection component 240 detects the resonant frequency of the pressure sensor 210 and the compensation sensor 220, it only needs to subtract the resonant frequency output by the compensation sensor 220 from the resonant frequency output by the pressure sensor 210 and then extract the final resonant frequency, thereby eliminating the influence of environmental factors and improving the detection accuracy of the compensation system 200 for the pressure to be detected.

[0193] Finally, it should be noted that the above embodiments are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto, and any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on 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 film is disposed on one side of the piezoelectric component, and the resonant film is directly or indirectly connected to the piezoelectric component; A pressure resonance component is arranged on one side of the resonance film and connected to the resonance film, a resonance groove is arranged on the side of the pressure resonance component facing the resonance film, the resonance film is arranged at the opening of the resonance groove, and the resonance groove and the resonance film cooperate to form a resonance cavity, a pressure cavity is arranged on the side of the pressure resonance component away from the resonance film, a pressure sensitive film is arranged between the resonance groove and the pressure cavity, and the pressure cavity is used to receive the pressure to be detected; Wherein, along the direction from the resonant film to the pressure resonance component, the projection of the resonant cavity at least partially falls within the projection range of the pressure cavity.

2. The piezoelectric resonant pressure sensor according to claim 1, characterized in that: At least a portion of an oxide layer is provided at the connection between the resonant film and the pressure resonance component.

3. The piezoelectric resonant pressure sensor according to claim 2, characterized in that: The resonant film is bonded to the pressure resonance component, and at least a portion of the oxide layer is formed at the bonding location between the resonant film and the pressure resonance component.

4. The piezoelectric resonant pressure sensor according to claim 2 or 3, characterized in that: The resonant film is processed from an SOI wafer, the pressure resonance component is processed from an Si wafer, the device layer of the SOI wafer is bonded to the Si wafer, and at least part of the oxide layer is formed at the connection position between the SOI wafer and the Si wafer.

5. The piezoelectric resonant pressure sensor according to claim 1, characterized in that: Along the direction from the resonance film to the pressure resonance component, the projection of the resonance cavity falls within the projection range of the pressure cavity.

6. The piezoelectric resonant pressure sensor according to claim 1, characterized in that: The pressure resonance component comprises at least one connection structure, and the connection structure is arranged on a side of the pressure resonance component facing the pressure sensitive film. At least one of the connection structures cooperates with the pressure sensitive film to form the resonance groove.

7. The piezoelectric resonant pressure sensor according to claim 6, characterized in that: The pressure resonance component further comprises at least one resonance substrate, which is arranged on a side of the pressure resonance component away from the resonance film. The at least one resonance substrate cooperates with the pressure sensitive film to form the pressure chamber.

8. 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 resonance component, and the cover is directly or indirectly connected to the piezoelectric component.

9. The resonant pressure sensor according to claim 1, characterized in that: The invention also comprises a protection layer, wherein the protection layer is arranged on a side of the piezoelectric component away from the resonance component.

10. 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 9, wherein the at least two piezoelectric resonant pressure sensors comprise at least one pressure sensor and at least one compensation sensor.

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