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 assembly and a pressure sensitive assembly. The resonant assembly is provided with a resonant cavity. The pressure-sensitive component is arranged on one side, deviating from the piezoelectric component, of the resonance component, a pressure-sensitive film, a first oxide layer and the resonance substrate in the pressure-sensitive component are matched to form a pressure cavity, an opening of the pressure cavity deviates from the resonance component, and the pressure cavity is used for receiving to-be-detected pressure. Wherein the pressure sensitive assembly seals the opening of the resonant cavity, and the projection of at least part of the resonant cavity falls into the projection range of the pressure cavity in the direction from the resonant assembly to the pressure sensitive 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 and a compensation system to expand the pressure detection range of the piezoelectric resonant pressure sensor and expand the application range of the piezoelectric resonant pressure sensor.

[0007] In the first aspect, the present application provides an example of a piezoelectric resonant pressure sensor for use 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. A resonant cavity is provided on the side of the resonant component away from the piezoelectric component, and the opening of the resonant cavity is arranged away from the piezoelectric component. The pressure-sensitive component is arranged on the side of the resonant component away from the piezoelectric component. The pressure-sensitive component includes a pressure-sensitive film, a buried oxide layer, and a resonant substrate. The pressure-sensitive film, the buried oxide layer, and the resonant substrate cooperate to form a pressure cavity. The opening of the pressure cavity is arranged away from the resonant component, and the pressure cavity is used to receive the pressure to be detected.

[0008] The pressure sensitive component closes the opening of the resonance cavity, and along the direction from the resonance component to the pressure sensitive component, at least part of the projection of the resonance cavity falls within the projection range of the pressure cavity.

[0009] Based on the above, according to the piezoelectric resonant pressure sensor provided by 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 and the pressure chamber receiving the pressure to be detected are arranged at intervals. And since a resonant cavity is provided on the side of the resonant component away from the piezoelectric component, when the piezoelectric component drives the resonant component to vibrate, the resonant cavity can provide a deformation space for the piezoelectric component, thereby 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 can be widely used in the core technology field of the electronics industry.

[0011] In addition, compared with the existing piezoelectric resonant pressure sensors in which the resonant cavity and the pressure cavity are staggered, or other components other than the pressure-sensitive film are arranged between the resonant cavity and the pressure cavity, the piezoelectric resonant pressure sensor provided in the example of the present application has a projection of the resonant cavity at least partially falling within the projection range of the pressure cavity along the direction from the resonant film 1221 to the pressure-sensitive component, occupies less space, can reduce the volume of the resonant piezoelectric sensor, is conducive to the miniaturization of the piezoelectric resonant pressure sensor, and is conducive to the integrated development of the piezoelectric resonant pressure sensor.

[0012] In the example of this application, the buried oxide layer can ensure the insulation between the pressure sensitive film and the resonant substrate, thereby ensuring the reliability of the piezoelectric resonant pressure sensor. The buried oxide layer can also reduce the impact of temperature in the environmental factors on the piezoelectric resonant pressure sensor, thereby ensuring the detection accuracy of the resonant pressure sensor.

[0013] In some possible implementations, the resonant component includes a resonant film layer and a resonant connection layer connected to each other, the resonant film layer is connected to the piezoelectric component, the resonant connection layer is arranged on a side of the resonant film layer away from the piezoelectric component layer, and the resonant connection layer connects the resonant film layer and the pressure sensitive component. A first through hole is arranged on the resonant connection layer, and the first through hole cooperates with the resonant film layer to form a resonant cavity.

[0014] Since a resonant component is provided on one side and a piezoelectric component is provided on the other side of the resonant component, the pressure to be detected acting on the pressure sensitive component can be transmitted to the piezoelectric component and the resonant component through the pressure sensitive component, thereby causing the piezoelectric component to vibrate. 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, thereby reducing the possibility of damage to the piezoelectric component due to deformation of the piezoelectric component due to vibration.

[0015] When the piezoelectric component vibrates, the resonant cavity can provide a deformation space for the vibration of the piezoelectric component, thereby reducing the possibility of damage to the piezoelectric component due to deformation caused by vibration.

[0016] In some possible implementations, the resonant component further includes a first oxide layer, and the resonant film layer and the resonant connecting layer are connected via the first oxide layer.

[0017] By providing the first oxide layer, the insulation between the resonant component and the pressure sensitive component can be further ensured, and the reliability of the piezoelectric resonant pressure sensor can be further ensured.

[0018] The first oxide layer can also reduce the influence of temperature in environmental factors on the piezoelectric resonant pressure sensor, further ensuring the detection accuracy of the resonant pressure sensor.

[0019] In some possible implementations, the piezoelectric resonant pressure sensor further includes a second oxide layer, and the pressure sensitive component is connected to the resonant component through the second oxide layer.

[0020] The second oxide layer can be provided to further ensure the insulation between the pressure sensitive component and the resonant component, thereby further ensuring the reliability of the piezoelectric resonant pressure sensor.

[0021] The second oxide layer can also reduce the impact of temperature in environmental factors on the piezoelectric resonant pressure sensor, further ensuring the detection accuracy of the resonant pressure sensor.

[0022] In some possible implementations, a second through hole is provided on the resonant connection layer, the second through hole is spaced apart from the first through hole, the resonant film layer closes the opening of the second through hole near the resonant film layer, and the resonant connection layer closes the opening of the second through hole near the resonant connection layer. Alternatively, a groove is provided on the piezoelectric component and the resonant component, the groove runs through the piezoelectric component and the resonant component, the groove is spaced apart from the first through hole, and the pressure sensitive component closes the opening of the groove toward the pressure sensitive component.

[0023] By providing the second through hole, part of the resonant connection layer can be divided into at least one connection structure and at least one resonant base, the connection structure and the resonant base are arranged at intervals. The second through hole is arranged between the connection structure and the resonant base.

[0024] The connecting structure can connect the pressure sensitive film and the piezoelectric component, and the connecting 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, thereby 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.

[0025] By providing the second through hole, a distance can be maintained between the resonant substrate and the connecting structure, thereby reducing the cross-sectional area of ​​the connecting structure, so that the working stress transmitted to the piezoelectric component through the connecting structure is more concentrated, which is beneficial to improving the detection accuracy of the piezoelectric resonant pressure sensor.

[0026] Since the opening of the groove away from the pressure-sensitive component mentioned in the example of this application is in an open state, that is, the opening of the groove can be opened to the position where the piezoelectric component is located, specifically, it can be opened to the side of the piezoelectric component away from the resonant film. Based on this, the resonant film can divide the piezoelectric layer into at least two parts, and along the direction from the resonant groove to the pressure cavity, the projection of the groove is located between the projection of at least one electrode and the projection of the resonant cavity, that is, the groove can divide the piezoelectric component 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 electrode can be located in the part of the piezoelectric component that hardly vibrates. In this way, the influence of the pressure to be detected on the electrode can be reduced, and the possibility of the electrode vibrating under the action of the pressure to be detected can be reduced, thereby ensuring the reliability of the piezoelectric resonant pressure sensor.

[0027] In some possible implementations, the connection layer includes at least one connection structure and at least one resonant substrate, the connection structure and the resonant substrate are arranged at intervals, the second through hole is arranged between the connection structure and the resonant substrate, or a portion of the groove is arranged between the connection structure and the resonant substrate.

[0028] In some possible implementations, when the piezoelectric resonant pressure sensor is provided with a groove, the resonant film layer includes a first connecting part, a second connecting part and a resonant film, the resonant film is connected to the first connecting part, the second connecting part is arranged on the side of the first connecting part away from the resonant film, the first connecting part and the second connecting part are spaced apart, and part of the groove is arranged between the first connecting part and the second connecting part.

[0029] In some possible implementations, along the direction from the resonance component toward the pressure sensitive component, the projection of the resonance cavity falls within the projection range of the pressure cavity.

[0030] 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. Thus, compared with the existing piezoelectric resonant pressure sensors in which the resonant cavity and the pressure cavity are staggered, or other components other than the pressure-sensitive film are arranged between the resonant cavity and the pressure cavity, the piezoelectric resonant pressure sensor provided in the example of the present application follows the direction from the resonant film to the pressure-sensitive component, and the projection of the resonant cavity falls within the projection range of the pressure cavity, which occupies less space and can further reduce the volume of the resonant piezoelectric sensor, which is beneficial to the miniaturization of the piezoelectric resonant pressure sensor and the integrated development of the piezoelectric resonant pressure sensor.

[0031] In some possible implementations, the cover is disposed on a side of the piezoelectric component facing away from the pressure sensitive component, and the cover is directly or indirectly connected to the piezoelectric component.

[0032] In a vacuum environment, the cover can be used to encapsulate the piezoelectric bending resonator. The cover can be set 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 is in a vacuum environment when working, and then improve the value corresponding to the quality factor of the resonant pressure sensor to ensure the working performance of the resonant pressure sensor.

[0033] 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.

[0034] 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.

[0035] 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

[0036] Figure 1 A schematic diagram of the structure of a piezoelectric resonant pressure sensor provided as an example in this application.

[0037] Figure 2 A top view of a schematic diagram of the structure of a piezoelectric resonant pressure sensor provided as an example in this application.

[0038] Figure 3 for Figure 2 Sectional view of AA.

[0039] Figure 4 for Figure 2 Cross-sectional view of BB.

[0040] Figure 5 A schematic diagram of the internal structure of a piezoelectric resonant pressure sensor provided as an example in this application.

[0041] Figure 6 A schematic diagram of the structure of another piezoelectric resonant pressure sensor provided as an example in this application.

[0042] Figure 7 A top view of a schematic structural diagram of another piezoelectric resonant pressure sensor provided as an example in this application.

[0043] Figure 8 for Figure 7 Middle CC section view.

[0044] Fig. 9 for Figure 8 A local enlarged schematic diagram of point A in the middle.

[0045] Fig.10 A schematic diagram of the working principle of a piezoelectric resonant pressure sensor provided as an example in this application.

[0046] Fig.11 A schematic diagram of the resonance principle of a piezoelectric resonant pressure sensor provided as an example in this application.

[0047] 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.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] Fig.16A 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.

[0052] Fig.17 A schematic diagram of the structure of another piezoelectric resonant pressure sensor provided as an example in this application.

[0053] Fig.18 A schematic diagram of the structure of a compensation system provided for the example of this application.

[0054] Fig.19 A schematic diagram of the working process of a compensation system provided as an example of this application.

[0055] Description of reference numerals:

[0056] 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 component; 121, resonant cavity; 122, resonant film layer; 1221, resonant film; 1222, first connecting portion; 1223, second connecting portion; 123, resonant connecting layer; 1231, connecting structure; 1232, resonant Resonance base; 124, first oxide layer; 130, pressure sensitive component; 131, pressure chamber; 132, pressure sensitive film; 133, resonant substrate; 140, second oxide layer; 150, protective layer; 160, cover; 170, groove; 171, lead bridge; 172, beam structure; 420, buried oxide layer; 200, compensation system; 210, pressure sensor; 220, compensation sensor; 230, driving component; 240, detection component. DETAILED DESCRIPTION

[0057] 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.

[0058] 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.

[0059] 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.

[0060] 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.

[0061] 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.

[0062] 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.

[0063] 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).

[0064] 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.

[0065] 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 piezoelectric resonant pressure sensors. The measuring structure can be a detection circuit or other structure that can detect the pressure to be detected.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] Based on the above, the present application example provides a piezoelectric resonant pressure sensor and compensation system.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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 piezoelectric resonant pressure sensor structure schematic diagram provided in the 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 resonant pressure sensor 100 includes a piezoelectric component 110 , a resonant component 120 and a pressure sensitive component 130 .

[0074] The piezoelectric component 110 is directly or indirectly connected to an external circuit. A resonant cavity 121 is provided on the side of the resonant component 120 away from the piezoelectric component 110, and the opening of the resonant cavity 121 is arranged away from the piezoelectric component 110. The pressure sensitive component 130 is arranged on the side of the resonant component 120 away from the piezoelectric component 110, and the pressure sensitive component 130 includes a pressure sensitive film 132, a buried oxide layer 420 and a resonant substrate 133, and the pressure sensitive film 132, the buried oxide layer 420 and the resonant substrate 133 cooperate to form a pressure cavity 131, and the opening of the pressure cavity 131 is arranged away from the resonant component 120, and the pressure cavity 131 is used to receive the pressure to be detected.

[0075] The pressure sensitive component 130 closes the opening of the resonance cavity 121 , and along the direction from the resonance component 120 to the pressure sensitive component 130 , at least a portion of the projection of the resonance cavity 121 falls within the projection range of the pressure cavity 131 .

[0076] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the pressure chamber 131 can receive the pressure to be detected. Since the pressure chamber 131 is arranged on the side of the pressure sensitive component 130 away from the resonant component 120, and the pressure sensitive component 130 can be directly or indirectly connected to the resonant film 1221, the pressure to be detected can be transmitted to the resonant component 120 through the pressure sensitive component 130. Since the resonant component 120 is arranged on one side of the piezoelectric component 110, the resonant component 120 is directly or indirectly connected to the piezoelectric component 110, and the pressure to be detected indirectly acting on the resonant component 120 can be transmitted to the piezoelectric component 110. Based on the characteristics of the piezoelectric component 110, the pressure to be detected can be detected.

[0077] The resonant film 1221 can close the opening of the resonant cavity 121 away from the pressure sensitive component 130. The resonant film 1221 can also be provided with some through holes so that the resonant film 1221 does not close the opening of the resonant cavity 121 away from the pressure sensitive component 130, as described below.

[0078] Next, the structure of the piezoelectric resonant pressure sensor 100 is described in detail.

[0079] The pressure to be detected received by the pressure sensitive component 130 may be the pressure applied directly or indirectly to the pressure sensitive component 130 by the fluid, and the fluid may be liquid, gas, etc.

[0080] The pressure sensitive component 130 includes a pressure sensitive film 132, a buried oxide layer 420 and a resonant substrate 133. The pressure sensitive film 132, the buried oxide layer 420 and the resonant substrate 133 cooperate with each other to form a pressure cavity 131. The buried oxide layer 420 is disposed between the pressure sensitive film 132 and the resonant substrate 133, and the buried oxide layer 420 can connect the pressure sensitive film 132 and the resonant substrate 133.

[0081] Exemplarily, the buried oxide layer 420 may overlap with the resonant substrate 133 , the pressure sensitive film 132 may be the bottom wall of the pressure cavity 131 , and the buried oxide layer 420 and the resonant substrate 133 may cooperate to form the side wall of the pressure cavity 131 .

[0082] For example, the pressure sensitive film 132 and the buried oxide layer 420 may overlap each other, and the buried oxide layer 420 is disposed close to the resonant substrate 133. In this case, the pressure sensitive film 132 and the buried oxide layer 420 may receive the pressure to be detected together, the buried oxide layer 420 may be the bottom wall of the pressure chamber 131, and the resonant substrate 133 may be the side wall of the pressure chamber 131. The example of this application does not limit the specific implementation of the pressure chamber 131.

[0083] The pressure sensitive film 132 and the resonant substrate 133 can both be made of silicon or other semiconductor materials. The buried oxide layer 420 can be made of silicon oxide or other materials. The manufacturing material of the buried oxide layer 420 can be different based on the manufacturing materials of the pressure sensitive film 132 and the resonant substrate 133. The specific setting of the buried oxide layer 420 is not limited in the example of this application.

[0084] The present application example is described by taking the case where the pressure sensitive film 132 and the resonant substrate 133 are both made of silicon material and the buried oxide layer 420 is made of silicon oxide material. Compared with silicon material, silicon oxide material has better insulation and lower thermal conductivity.

[0085] The buried oxide layer 420 can ensure the insulation between the pressure sensitive film 132 and the resonant substrate 133 , and can also ensure the insulation between the pressure component and the resonant component 120 , thereby ensuring the reliability of the piezoelectric resonant pressure sensor 100 .

[0086] The buried oxide layer 420 can also reduce the impact of temperature in environmental factors on the piezoelectric resonant pressure sensor 100, thereby ensuring the detection accuracy of the resonant pressure sensor.

[0087] The resonant substrate 133 and the pressure sensitive film 132 may be an integrated structure. In this case, the pressure chamber 131 may be a cavity formed by removing the middle portion of a block-shaped structure.

[0088] The resonant substrate 133 may also be connected to the pressure sensitive film 132 by bonding or other means. In this case, the resonant substrate 133 may include a plurality of resonant substrates, and different resonant substrates 133 may be connected to the sidewalls of the corresponding pressure sensitive film 132 .

[0089] By setting a pressure sensitive film 132, a buried oxide layer 420 and a resonant substrate 133 to form a pressure chamber 131, an operator can control a fluid such as gas or liquid to apply pressure to the cavity wall of the pressure chamber 131. By setting the pressure chamber 131, the pressure to be detected that directly or indirectly acts on the pressure sensitive film 132 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 131.

[0090] In the example of the present application, the resonant substrate 133, the connection structure and the pressure sensitive film 132 as well as other structures of the pressure resonance component 120 can be integrally formed, so that the structural size of the piezoelectric resonant pressure sensor 100 can be reduced and the processing cost of the piezoelectric resonant pressure sensor 100 can be reduced.

[0091] The resonant component 120 can be directly or indirectly connected to the side of the pressure sensitive component 130 away from the pressure chamber 131. The piezoelectric component 110 is arranged on the side of the resonant component 120 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 pressure to be detected is detected through the piezoelectric component 110.

[0092] 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, the two opposite sides of the piezoelectric layer 114 can generate a potential difference. The positive piezoelectric effect and the inverse piezoelectric effect of the piezoelectric layer 114 can be used to detect the vibration of the piezoelectric resonant pressure sensor 100, 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. The specific description of the piezoelectric component 110 can be found below.

[0093] 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.

[0094] 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.

[0095] Along the direction from the resonant film 1221 to the pressure sensitive component 130 , the projection of the resonant cavity 121 at least partially falls within the projection range of the pressure cavity 131 .

[0096] The projection of the resonant cavity 121 may completely fall within the projection range of the pressure cavity 131 . At this time, the geometric center of the projection of the resonant cavity 121 may overlap with the geometric center of the projection of the pressure cavity 131 , and there may also be a distance between the geometric center of the resonant cavity 121 and the geometric center of the pressure cavity 131 .

[0097] Part of the projection of the resonance cavity 121 may also fall within the projection range of the pressure cavity 131 , that is, the projection of the resonance cavity 121 partially overlaps with the projection of the pressure cavity 131 .

[0098] The shape of the pressure chamber 131 may be the same as that of the resonant cavity 121, or the shape of the pressure chamber 131 may be different from that of the resonant cavity 121. The present application example is described here only by taking the pressure chamber 131 as an example. For example, the shape of the pressure chamber 131 may be cylindrical, the shape of the pressure chamber 131 may be prismatic, or the shape of the pressure chamber 131 may be irregular.

[0099] There may be one pressure chamber 131, or there may be multiple pressure chambers 131 spaced apart. There may be only one resonance chamber 121, or there may be multiple resonance chambers 121, which is not limited in the present application example.

[0100] The example of the present application does not specifically limit the positional relationship between the resonance cavity 121 and the pressure cavity 131, as long as it is ensured that the projection of at least part of the resonance cavity 121 coincides with the projection of the pressure cavity 131, thereby ensuring that the pressure to be detected received by the pressure cavity 131 can be transmitted to the piezoelectric component 110 through the resonance component 120, and the pressure to be detected can be detected by the piezoelectric component 110.

[0101] 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 by 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 and the pressure chamber 131 receiving the pressure to be detected are arranged at intervals. And since the resonant cavity 121 is provided on the side of the resonant component 120 away from the piezoelectric component 110, 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, thereby reducing the possibility that the piezoelectric component 110 is damaged due to a large deformation amount caused by vibration.

[0102] 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.

[0103] In addition, compared with the existing piezoelectric resonant pressure sensor 100 in which the resonant cavity 121 and the pressure cavity 131 are staggered, or other components other than the pressure sensitive film 132 are arranged between the resonant cavity 121 and the pressure cavity 131, the piezoelectric resonant pressure sensor 100 provided in the example of the present application has a projection of the resonant cavity 121 at least partially falling within the projection range of the pressure cavity 131 along the direction from the resonant film 1221 to the pressure sensitive component 130, occupies less space, can reduce the volume of the resonant piezoelectric sensor, is conducive to the miniaturization of the piezoelectric resonant pressure sensor 100, and is conducive to the integrated development of the piezoelectric resonant pressure sensor 100.

[0104] In the example of the present application, the buried oxide layer 420 can ensure the insulation between the pressure sensitive film 132 and the resonant substrate 133, thereby ensuring the reliability of the piezoelectric resonant pressure sensor 100. The buried oxide layer 420 can also reduce the impact of temperature in the environmental factors on the piezoelectric resonant pressure sensor 100, thereby ensuring the detection accuracy of the resonant pressure sensor.

[0105] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, along the direction from the resonant component 120 toward the pressure sensitive component 130 , the projection of the resonant cavity 121 falls within the projection range of the pressure cavity 131 .

[0106] By following the direction from the resonant cavity 121 to the pressure cavity 131, the projection of the resonant cavity 121 can completely fall within the projection range of the pressure cavity 131. In this way, compared with the existing piezoelectric resonant pressure sensor 100 in which the resonant cavity 121 and the pressure cavity 131 are staggered, or other components other than the pressure sensitive film 132 are arranged between the resonant cavity 121 and the pressure cavity 131, the piezoelectric resonant pressure sensor 100 provided in the example of the present application follows the direction from the resonant film 1221 to the pressure sensitive component 130, and the projection of the resonant cavity 121 falls within the projection range of the pressure cavity 131, which occupies less space and can further reduce the volume of the resonant piezoelectric sensor, which is conducive to the miniaturization of the piezoelectric resonant pressure sensor 100 and the integrated development of the piezoelectric resonant pressure sensor 100.

[0107] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the resonant component 120 includes a resonant film layer 122 and a resonant connection layer 123 connected to each other, the resonant film layer 122 is connected to the piezoelectric component 110, the resonant connection layer 123 is arranged on the side of the resonant film layer 122 away from the piezoelectric component 110, and the resonant connection layer 123 connects the resonant film layer 122 and the pressure sensitive component 130. A first through hole is provided on the resonant connection layer 123, and the first through hole cooperates with the resonant film layer 122 to form a resonant cavity 121.

[0108] The resonant film layer 122 and the resonant connecting layer 123 may be integrally formed, or they may be connected together via a connector. The example of the present application does not limit the specific forming method of the resonant film layer 122 and the resonant connecting layer 123 .

[0109] The resonant connection layer 123 is provided with a first through hole, and the first through hole cooperates with the resonant film layer 122 to form a resonant cavity 121, and the opening of the resonant cavity 121 is away from the resonant film layer 122. Since the pressure sensitive component 130 is provided on the side of the resonant component 120 away from the piezoelectric component 110, and the pressure sensitive component 130 can close the opening of the resonant cavity 121, it is convenient to transmit the pressure to be detected received by the pressure sensitive component to the piezoelectric component 110 relatively completely.

[0110] Based on the material characteristics of the piezoelectric component 110, the piezoelectric component 110 vibrates when receiving voltage stimulation or current stimulation. For a detailed description of the piezoelectric component 110, please refer to the following.

[0111] In summary, since the pressure sensitive component 130 is disposed on one side of the resonant component 120, and the piezoelectric component 110 is disposed on the other side of the resonant component 120. Based on this, 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 converted into stress on the piezoelectric component 110 and the resonant component, thereby causing a change in the structural resonant frequency. Since the resonant cavity 121 is disposed 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, thereby reducing the possibility of the piezoelectric component 110 being damaged due to deformation of the piezoelectric component 110 due to vibration.

[0112] When the piezoelectric component 110 vibrates, the resonant cavity 121 can provide a deformation space for the vibration of the piezoelectric component 110 , thereby reducing the possibility of damage to the piezoelectric component 110 due to deformation caused by vibration.

[0113] The resonant cavity 121 mentioned in the above example can maintain a vacuum inside the resonant cavity 121, or the cavity can be filled with a medium.

[0114] 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.

[0115] Exemplarily, the piezoelectric resonant pressure sensor 100 may be a relative pressure sensor. A relative pressure sensor is measured based on atmospheric pressure or a certain fixed pressure, so the measurement result of the relative pressure sensor is relative to the atmospheric pressure or a certain fixed pressure. Therefore, the relative pressure sensor can be used to measure the difference in relative pressure.

[0116] Users can select a suitable absolute pressure sensor or relative pressure sensor according to their needs. The present application example does not limit whether a medium is injected into the cavity of the piezoelectric resonant pressure sensor 100.

[0117] Based on the above example, a piezoelectric resonant pressure sensor 100 is provided. Figure 5 A schematic diagram of the internal structure of a piezoelectric resonant pressure sensor provided as an example of this application, Figure 6 A schematic diagram of the structure of another piezoelectric resonant pressure sensor provided as an example of this application, Figure 7 A top view of another piezoelectric resonant pressure sensor structure schematic diagram provided for the example of this application, Figure 8 for Figure 7 Middle CC section view.

[0118] The piezoelectric resonant pressure sensor 100 may be provided with a groove. The groove 170 may be implemented in various ways.

[0119] Next, the specific implementation of the groove 170 is described.

[0120] For example, please refer to Figure 5 The resonant connection layer 123 is provided with a second through hole, the second through hole is spaced apart from the first through hole, the resonant film layer 122 closes the opening of the second through hole close to the resonant film layer 122, and the resonant connection layer 123 closes the opening of the second through hole close to the resonant connection layer 123. The second through hole cooperates with other structures to form a groove 170.

[0121] The groove 170 may be formed by etching, or by other methods, which is not limited in this example of the present application.

[0122] There may be one second through hole, or there may be two, three or even more second through holes. The example of the present application does not limit the specific setting of the second through holes.

[0123] The second through hole can be provided to divide the partial resonant connection layer 123 into at least one connection structure 1231 and at least one resonant base 1232. The connection structure 1231 and the resonant base 1232 are arranged at intervals. The second through hole is provided between the connection structure 1231 and the resonant base 1232.

[0124] The connecting structure 1231 can connect the pressure sensitive film 132 and the piezoelectric component 110, and the connecting structure 1231 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, thereby reducing the possibility of damage to the piezoelectric component 110, improving the pressure-bearing capacity of the resonant film 1221, 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.

[0125] By setting the second through hole, a distance can be maintained between the resonant substrate 1232 and the connecting structure 1231, thereby reducing the cross-sectional area of ​​the connecting structure 1231, so that the working stress transmitted to the piezoelectric component 110 through the connecting structure 1231 is more concentrated, which is beneficial to improving the detection accuracy of the piezoelectric resonant pressure sensor 100.

[0126] Or, refer to Figure 6 to Figure 8 , a groove 170 is provided on the piezoelectric component 110 and the resonant component 120, the groove 170 penetrates the piezoelectric component 110 and the resonant component 120, the groove 170 is spaced apart from the first through hole, and the pressure sensitive component 130 closes the opening of the groove 170 toward the pressure sensitive component 130. A groove 170 is provided on the piezoelectric component 110 and the resonant component 120, the groove 170 penetrates the piezoelectric component 110 and the resonant component 120, the groove 170 is spaced apart from the first through hole, and the pressure sensitive component 130 closes the opening of the groove 170 toward the pressure sensitive component 130. The opening of the groove 170 away from the pressure sensitive component 130 is in an open state. Part of the first through hole may overlap with the groove 170.

[0127] Since the opening of the groove 170 away from the pressure sensitive component 130 mentioned in the example of this application is in an open state, that is, 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 1221. Based on this, the resonant film 1221 can divide the piezoelectric layer 114 into at least two parts, and along the direction from the resonant groove to the pressure cavity 131, the projection of the groove 170 is located between the projection of at least one 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, and at least one 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 electrode can be reduced, and the possibility of the 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.

[0128] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, Fig. 9 for Figure 8 Please refer to the enlarged schematic diagram of the part A in the middle. Fig. 9 In the case where the piezoelectric resonant pressure sensor 100 is provided with a groove 170, the resonant film layer 122 includes a first connecting portion 1222, a second connecting portion 1223 and a resonant film 1221, the resonant film 1221 is connected to the first connecting portion 1222, the second connecting portion 1223 is arranged on a side of the first connecting portion 1222 away from the resonant film 1221, the first connecting portion 1222 and the second connecting portion 1223 are spaced apart, and part of the groove 170 is arranged between the first connecting portion 1222 and the second connecting portion 1223.

[0129] The first connection part 1222 , the second connection part 1223 and the resonant film 1221 may be provided with one or more. The example of the present application is described by taking the example that the resonant film 1221 is provided with one, and the first connection part 1222 and the second connection part 1223 are provided with two.

[0130] The two first connection parts 1222 can be respectively arranged on opposite sides of the resonance film 1221, the number of the second connection parts 1223 and the first connection parts 1222 are equal and correspond one to one, the second connection parts 1223 can be arranged on the side of the corresponding first connection part 1222 away from the resonance film 1221, and part of the groove 170 is arranged between the first connection part 1222 and the second connection part 1223.

[0131] Part of the third connection hole is arranged in the piezoelectric component 110. The part of the third connection hole arranged in the piezoelectric component 110, the part of the third connection hole arranged between the first connection part 1222 and the second connection part 1223, and the part of the third connection hole arranged between the connection structure 1231 and the resonant base 1232 can form a complete third connection hole.

[0132] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, please refer to Fig. 9 The resonant connection layer 123 includes at least one connection structure 1231 and at least one resonant base 1232, and the connection structure 1231 and the resonant base 1232 are arranged at intervals. The second through hole is arranged between the connection structure 1231 and the resonant base 1232. Alternatively, a portion of the groove 170 is arranged between the connection structure 1231 and the resonant base 1232.

[0133] The connection structure 1231 may be cylindrical, prism-shaped, truncated cone-shaped or other shapes. At least one connection structure 1231 may be provided, or two, three, or even more connection structures 1231 may be provided.

[0134] Based on the above, since the pressure sensitive film 132 is disposed on one side of the connection structure 1231, the other side of the connection structure 1231 is directly or indirectly connected to the piezoelectric component 110. Based on this, the pressure to be detected acting on the pressure sensitive film 132 can be transmitted to the piezoelectric component 110 through the connection structure 1231, thereby causing the vibration of the piezoelectric component 110. Since the resonant cavity 121 is disposed 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, thereby reducing the possibility of the piezoelectric component 110 being damaged due to deformation of the piezoelectric component 110 due to vibration.

[0135] Fig.10 A schematic diagram of the working principle of a piezoelectric resonant pressure sensor provided in this application example, referring to Fig.10 , the connection structure 1231 can change the direction of action of the pressure to be detected.

[0136] 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 1221 through the connecting structure 1231. The connecting structure 1231 can convert the pressure to be detected perpendicular to the pressure sensitive film 132 into a working stress having an angle between its acting direction and the acting direction of the pressure to be detected.

[0137] 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 due to deformation of the piezoelectric component 110 caused by vibration. The connection structure 1231 can directly or indirectly connect the pressure sensitive film 132 and the piezoelectric component 110, and the connection structure 1231 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 1221, 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.

[0138] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the side of the connecting structure 1231 close to the pressure sensitive film 132 can be an anchor point, the distance between the anchor point and the resonant film 1221 is a first distance, and the distance between the anchor point and the pressure sensitive film 132 is a second distance, and the first distance is greater than the second distance.

[0139] The anchor point is the main stress point of the connection structure 1231.

[0140] By setting the first distance to be greater than the second distance, the resonant film 1221, the pressure sensitive film 132 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 1231 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.

[0141] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the resonant component 120 may further include a first oxide layer 124 , and the resonant film layer 122 and the resonant connecting layer 123 are connected via the first oxide layer 124 .

[0142] The resonant film 1221 in the resonant component 120 can be made of silicon or other semiconductor materials, and the first oxide layer 124 can be made of silicon oxide or other materials. The manufacturing material of the first oxide layer 124 can be different based on the different manufacturing materials of the resonant film 1221. The example of this application does not limit the specific setting of the first oxide layer 124.

[0143] The present application example is described by taking the case where the resonant film 1221 and the resonant substrate 133 are both made of silicon material and the first oxide layer 124 is made of silicon oxide material as an example. Compared with silicon material, silicon oxide material has better insulation and lower thermal conductivity.

[0144] The first oxide layer 124 can be provided to further ensure the insulation between the resonant component 120 and the pressure sensitive component 130 , thereby further ensuring the reliability of the piezoelectric resonant pressure sensor 100 .

[0145] The first oxide layer 124 can also reduce the impact of temperature in environmental factors on the piezoelectric resonant pressure sensor 100 , further ensuring the detection accuracy of the resonant pressure sensor.

[0146] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the piezoelectric resonant pressure sensor 100 further includes a second oxide layer 140 , and the pressure sensitive component 130 is connected to the resonant component 120 via the second oxide layer 140 .

[0147] The resonant connection layer 123 in the resonant component 120 and the pressure sensitive film 132 in the pressure sensitive component 130 can both be made of silicon or other semiconductor materials, and the second oxide layer 140 can be made of silicon oxide or other materials. The manufacturing material of the second oxide layer 140 can be different based on the different manufacturing materials of the resonant connection layer 123 and the pressure sensitive film 132. The example of this application does not limit the specific setting of the second oxide layer 140.

[0148] The present application example is described by taking the example that the resonant connection layer 123 and the pressure sensitive film 132 are made of silicon material and the second oxide layer 140 is made of silicon oxide material. Compared with silicon material, silicon oxide material has better insulation and lower thermal conductivity.

[0149] The second oxide layer 140 can be provided to further ensure the insulation between the pressure sensitive component 130 and the resonant component 120 , thereby further ensuring the reliability of the piezoelectric resonant pressure sensor 100 .

[0150] The second oxide layer 140 can also reduce the influence of temperature in environmental factors on the piezoelectric resonant pressure sensor 100 , further ensuring the detection accuracy of the resonant pressure sensor.

[0151] Next, the specific structure of the piezoelectric component 110 is described.

[0152] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, Fig.11 A schematic diagram of the resonance principle of a piezoelectric resonant pressure sensor provided for this application example, please refer to Figure 6 to Figure 11 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 .

[0153] The second electrode 115 may be disposed on a side of the resonant film 1221 away from the pressure resonance component 120, and a side of the second electrode 115 facing the resonant film 1221 may be directly or indirectly connected to the resonant film 1221. The piezoelectric layer 114 may be disposed on a side of the second electrode 115 away from the resonant film 1221, 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.

[0154] 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.

[0155] 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.

[0156] 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 molybdenum, 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.

[0157] 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.

[0158] 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.

[0159] 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.

[0160] The second electrode 115 may be a conductive layer laid on the side of the resonance film 1221 away from the resonance cavity 121 , 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 .

[0161] A piezoelectric layer 114 may be provided on a side of the second electrode 115 facing away from the resonance film 1221 .

[0162] 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.

[0163] 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.

[0164] Next, the principle of the piezoelectric resonant pressure sensor 100 is further introduced in combination with the specific structure of the piezoelectric component 110 .

[0165] The resonant film 1221 and the piezoelectric component 110 cooperate with each other to form a piezoelectric resonator.

[0166] 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.

[0167] 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:

[0168]

[0169] 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.

[0170] When the pressure chamber 131 receives the pressure to be detected, the pressure sensitive film 132 will deform and generate working stress under the action of the pressure to be detected. The connection structure 1231 can transfer the deformation and working stress of the pressure sensitive film 132 to the piezoelectric resonator, specifically to the piezoelectric layer 114. During the transmission process of the connection structure 1231, the connection structure 1231 can change the direction of action of the pressure to be detected, reducing the possibility of damage to the resonant film 1221. 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.

[0171] 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.

[0172] 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.

[0173] 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:

[0174]

[0175] 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.

[0176] When the piezoelectric layer 114 is deformed, the part of the piezoelectric layer 114 close to the resonance film 1221 is squeezed by the pressure to be detected, and the part of the piezoelectric layer 114 away from the resonance film 1221 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.

[0177] 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.

[0178] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, 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.13A 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.

[0179] Please refer to Figure 12 to Figure 16 In the case where only one groove is provided, the piezoelectric resonant pressure sensor 100 may be provided with a lead bridge 171 or may not be provided with a lead bridge.

[0180] When at least two grooves 170 are provided, a lead bridge 171 may be formed between two adjacent grooves 170. The lead bridge 171 may be provided with one, two, three, four or more. The multiple lead bridges 171 may be provided in a cross shape, a fennel shape, a straight shape or other irregular shapes.

[0181] Please refer to Figure 12 to Figure 16 At least two lead bridges 171 may be provided, or three, four or even more lead bridges 171 may be provided. 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 electrodes 111, which is not limited in this example of the present application.

[0182] By providing the lead bridge 171 , the location of the first lead electrode 111 can be adjusted to ensure the connection reliability between the first lead electrode 111 and the first electrode 113 .

[0183] Please refer to Fig.12 A 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.

[0184] An angle may be formed between the beam structure 172 and the lead bridge 171 .

[0185] 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.

[0186] 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.

[0187] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the piezoelectric component 110 may further include a seed layer, and the seed layer is disposed between the piezoelectric component 110 and the resonant component 120 , and specifically, may be disposed between the second electrode 115 and the resonant component 120 .

[0188] 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.

[0189] 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 1221 away from the pressure resonance component 120 . The cover 160 is directly or indirectly connected to the resonant film 1221 .

[0190] The cover 160 may be made of a silicon wafer, a glass wafer, an inorganic semiconductor material, or other amorphous inorganic non-metallic materials.

[0191] 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 1221 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.

[0192] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, please refer to Figure 8 A protective layer 150 may be provided on the side of the piezoelectric component 110 facing away from the resonant film 1221 . The protective layer 150 may be made of silicon dioxide or other moisture-proof materials.

[0193] 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.

[0194] 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.

[0195] 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.

[0196] 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.

[0197] 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.

[0198] 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.

[0199] 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.

[0200] 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.

[0201] Since the pressure sensor 210 and the compensation sensor 220 are integrated together and have the same resonant film 1221, environmental factors such as temperature, vibration, and impact will have the same impact on the resonant film 1221 of the pressure sensor 210 and the compensation sensor 220, so that the resonant film 1221 of the pressure sensor 210 and the compensation sensor 220 can have the same output based on the influence of environmental factors.

[0202] 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.

[0203] 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:

[0204] S101 , the driving component 230 is used to drive the pressure sensor 210 and the compensation sensor 220 .

[0205] 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 .

[0206] 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.

[0207] S104, the calculation module may also calculate the pressure value of the pressure to be detected based on the resonance frequency.

[0208] 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.

[0209] 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 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 a pressure sensitive component 130. The example of this application does not limit the specific structures of the pressure sensor 210 and the compensation sensor 220.

[0210] 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.

[0211] 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 component, wherein a resonant cavity is provided on a side facing away from the piezoelectric component, and an opening of the resonant cavity is arranged away from the piezoelectric component; A pressure sensitive component is arranged on a side of the resonant component away from the piezoelectric component, the pressure sensitive component comprises a pressure sensitive film, a buried oxide layer and a resonant substrate, the buried oxide layer is arranged between the pressure sensitive film and the resonant substrate, the pressure sensitive film, the buried oxide layer and the resonant substrate cooperate to form a pressure cavity, the opening of the pressure cavity is arranged away from the resonant component, and the pressure cavity is used to receive the pressure to be detected; The pressure sensitive component closes the opening of the resonance cavity, and along the direction from the resonance component to the pressure sensitive component, at least part of the projection of the resonance cavity falls within the projection range of the pressure cavity.

2. The piezoelectric resonant pressure sensor according to claim 1, characterized in that: The resonant component comprises a resonant film layer and a resonant connection layer connected to each other, the resonant film layer is connected to the piezoelectric component, the resonant connection layer is arranged on a side of the resonant film layer away from the piezoelectric component layer, and the resonant connection layer connects the resonant film layer and the pressure sensitive component; The resonant connection layer is provided with a first through hole, and the first through hole cooperates with the resonant film layer to form the resonant cavity.

3. The piezoelectric resonant pressure sensor according to claim 2, characterized in that: The resonant component further includes a first oxide layer, and the resonant film layer is connected to the resonant connection layer through the first oxide layer.

4. The piezoelectric resonant pressure sensor according to any one of claims 1 to 3, characterized in that: It also includes a second oxide layer, and the pressure sensitive component is connected to the resonant component through the second oxide layer.

5. The piezoelectric resonant pressure sensor according to claim 2, characterized in that: The resonant connection layer is provided with a second through hole, the second through hole is spaced apart from the first through hole, the resonant film layer closes the opening of the second through hole close to the resonant film layer, and the resonant connection layer closes the opening of the second through hole close to the resonant connection layer; or, The piezoelectric component and the resonant component are provided with grooves, the grooves penetrate the piezoelectric component and the resonant component, the grooves are spaced apart from the first through hole, and the pressure sensitive component closes the opening of the grooves toward the pressure sensitive component.

6. The piezoelectric resonant pressure sensor according to claim 5, characterized in that: The resonant connection layer includes at least one connection structure and at least one resonant base, and the connection structure and the resonant base are spaced apart; The second through hole is provided between the connection structure and the resonant base; or part of the groove is provided between the connection structure and the resonant base.

7. The piezoelectric resonant pressure sensor according to claim 5 or 6, characterized in that: In the case where the piezoelectric resonant pressure sensor is provided with the groove, the resonant film layer includes a first connecting part, a second connecting part and a resonant film, the resonant film is connected to the first connecting part, the second connecting part is arranged on the side of the first connecting part away from the resonant film, the first connecting part and the second connecting part are spaced apart, and part of the groove is arranged between the first connecting part and the second connecting part.

8. The piezoelectric resonant pressure sensor according to any one of claims 1 to 3, characterized in that: Along the direction from the resonant component to the pressure sensitive component, the projection of the resonant cavity falls within the projection range of the pressure cavity.

9. The 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.

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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