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 resonant component, a piezoelectric component, a connecting component and a pressure sensitive component. The resonant assembly is provided with a resonant cavity. The piezoelectric assembly is arranged on one side of the resonance assembly, and the connecting assembly is connected to the side, away from the resonance assembly, of the piezoelectric assembly and is directly or indirectly connected with an external circuit. The pressure sensitive assembly is arranged on the side, away from the resonance assembly, of the piezoelectric assembly, is used for receiving the pressure to be detected, and comprises a pressed area. At least part of the projection of the resonant cavity falls into the pressed area 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 can be used in scenarios with high accuracy requirements and harsh working environments.

[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 resonant component, a piezoelectric component, a connecting component, and a pressure-sensitive component. Among them, the resonant component is provided with a resonant cavity. The piezoelectric component is arranged on one side of the resonant component, the connecting component is connected to the side of the piezoelectric component away from the resonant component, and the connecting component is directly or indirectly connected to an external circuit. The pressure-sensitive component is arranged on the side of the piezoelectric component away from the resonant component, the pressure-sensitive component is used to receive the pressure to be detected, and the pressure-sensitive component includes a pressure-bearing area. Along the direction from the resonant component to the pressure-sensitive component, the projection of the resonant cavity at least partially falls into the pressure-bearing area.

[0008] According to the piezoelectric resonant pressure sensor provided in the example of this application, the pressure-bearing area can receive the pressure to be detected, and the pressure to be detected can be transmitted to the piezoelectric component through the pressure-sensitive component and the connecting component, and the pressure to be detected is detected by the characteristics of the piezoelectric component. Since the piezoelectric component is connected to one side of the pressure-sensitive component through the connecting component, the pressure-bearing area and the piezoelectric component are spaced apart, and since the resonant component with a resonant cavity is arranged on the side of the piezoelectric component away from the connecting component, when the piezoelectric component drives the resonant component to vibrate, the space between the connecting component and the piezoelectric component and the resonant cavity can provide deformation space for the piezoelectric component, thereby reducing the possibility of damage to the piezoelectric component due to large deformation caused by vibration.

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

[0010] In addition, compared with the existing piezoelectric resonant pressure sensor in which the resonant cavity and the pressure area are staggered, 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 to the pressure resonance component, which occupies less space and can reduce the volume of the resonant piezoelectric sensor, which is conducive to the miniaturization of the piezoelectric resonant pressure sensor and the integrated development of the piezoelectric resonant pressure sensor.

[0011] In some possible implementations, a pressure chamber is provided on a side of the pressure sensitive component facing away from the piezoelectric component, the pressure chamber is used to receive the pressure to be detected, and the pressurized area is located in the pressure chamber.

[0012] By setting up the pressure chamber, it is convenient for the operator to control the fluid such as gas or liquid to apply the pressure to be detected to the cavity wall of the pressure chamber. By setting up the pressure chamber, the force on the pressure sensitive film can be more concentrated.

[0013] In some possible implementations, the pressure sensitive component includes a pressure sensitive film and a resonant substrate. The resonant substrate is arranged on the side of the pressure sensitive film facing away from the piezoelectric component. The resonant substrate is provided with a first through hole. The pressure sensitive film closes the opening of the first through hole toward the resonant component. The pressure sensitive film cooperates with the first through hole to form a pressure chamber.

[0014] In some possible implementations, the pressure sensitive component includes a pressure sensitive film, a resonant substrate, and a second buried oxide layer, the second buried oxide layer is disposed between the pressure sensitive film and the resonant substrate, the pressure sensitive film and the resonant substrate are connected through the second buried oxide layer, the pressure sensitive component is provided with a first through hole, the first through hole penetrates the resonant substrate and the buried oxide layer, the pressure sensitive film closes the opening of the first through hole toward the resonant component, and the pressure sensitive film cooperates with the first through hole to form a pressure cavity. Alternatively, the first through hole penetrates the resonant substrate, the second buried oxide layer closes the opening of the first through hole toward the resonant component, and the second buried oxide layer cooperates with the first through hole to form a pressure cavity.

[0015] The second buried oxide layer can ensure the insulation between the pressure sensitive film and the resonant substrate, and can also ensure the insulation between the pressure component and the resonant component, thereby ensuring the reliability of the piezoelectric resonant pressure sensor.

[0016] The second buried oxide layer can also reduce the influence of temperature in environmental factors on the piezoelectric resonant pressure sensor, thereby ensuring the detection accuracy of the resonant pressure sensor.

[0017] In some possible implementations, the resonant component includes a resonant substrate and a resonant film connected to each other, a resonant groove is provided on the side of the resonant substrate facing the resonant film, and the resonant film and the resonant groove cooperate to form a resonant cavity. The side of the resonant film facing away from the resonant substrate is connected to the piezoelectric component.

[0018] In some possible implementations, the resonance component further includes a first buried oxide layer, and the resonance substrate and the resonance film are connected via the first buried oxide layer.

[0019] In some possible implementations, the piezoelectric component includes a first electrode layer, a piezoelectric layer, a second electrode layer, a connecting layer, and a lead electrode layer. The side of the lead electrode layer facing away from the resonance component is connected to the connecting component, and the side of the lead electrode layer facing the resonance component is connected to the first electrode, the connecting layer, and the second electrode, and the connection position of the lead electrode layer and the first electrode, the connection position of the lead electrode layer and the connecting layer, and the connection position of the lead electrode layer and the second electrode are spaced apart from each other. The side of the connecting layer facing the resonance component is connected to the piezoelectric layer and the first electrode, and the connection position of the connecting layer and the piezoelectric layer, and the connection position of the connecting layer and the first electrode are spaced apart from each other. Part of the piezoelectric layer is arranged between the first electrode and the second electrode, and the side of the second electrode facing away from the piezoelectric layer is connected to the resonance component.

[0020] Compared with the resistance detection type piezoelectric sensor which requires the setting of a Wheatstone bridge and the capacitance detection type pressure sensor which requires the setting of a capacitance bridge, the piezoelectric resonant pressure sensor provided in the example of the present application does not require the setting of an additional detection circuit. Only a piezoelectric component is needed to detect the pressure to be detected. The structure is simpler and the manufacturing cost is lower.

[0021] In some possible implementations, the second electrode layer includes at least one second electrode, the first electrode layer includes at least two first electrodes spaced apart, the lead electrode layer includes a second lead electrode and at least two first lead electrodes spaced apart, the connection layer includes a second connection portion and at least two first connection portions spaced apart, and the connection assembly includes a first connection electrode, a second connection electrode, a first connection portion, and a second connection portion. One side of the first lead electrode is connected to the first electrode, the other side of the first lead electrode is connected to the first connection electrode through the first connection portion, and the first connection electrode is directly or indirectly connected to a first portion of an external circuit. One side of the second lead electrode is connected to the second electrode, the other side of the second lead electrode is connected to the second connection electrode through the second connection portion, and the second connection electrode is directly or indirectly connected to a second portion of an external circuit.

[0022] 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.

[0023] 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.

[0024] 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

[0025] Figure 1 A schematic diagram of the internal structure of a piezoelectric resonant pressure sensor provided as an example in this application.

[0026] Figure 2 A schematic diagram of the internal structure of another piezoelectric resonant pressure sensor provided as an example in this application.

[0027] Figure 3 for Figure 2 A partial enlarged view of point A in the middle.

[0028] Figure 4 A schematic diagram of the resonance principle of a piezoelectric resonant pressure sensor provided as an example in this application.

[0029] Figure 5A schematic diagram of the internal structure of another piezoelectric resonant pressure sensor provided as an example in this application.

[0030] Figure 6 A schematic diagram of the working principle of a piezoelectric resonant pressure sensor provided as an example in this application.

[0031] Figure 7 A schematic diagram of the structure of a compensation system provided for the example of this application.

[0032] Figure 8 A schematic diagram of the working process of a compensation system provided as an example of this application.

[0033] Description of reference numerals:

[0034] 100, piezoelectric resonant pressure sensor; 110, resonant component; 111, resonant cavity; 112, resonant film; 113, resonant substrate; 120, piezoelectric component; 121, first electrode; 122, piezoelectric layer; 123, second electrode; 124, first lead electrode; 1241, first connection structure; 125, second lead electrode; 1251, second connection structure; 130, connection component; 131, first connection electrode; 132, second connection electrode; 133, first connection part; 134, second connection part; 140, pressure sensitive component; 141, pressure cavity; 142, pressure sensitive film; 143, resonant substrate; 320, first buried oxide layer; 420, second buried oxide layer; 510, first connection hole; 520, second connection hole; 200, compensation system; 210, pressure sensor; 220, compensation sensor. DETAILED DESCRIPTION

[0035] 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.

[0036] 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 are only for the purpose of describing specific examples and are not intended to limit this application; the terms "include" and "comprising" in the specification, claims and drawings of this application and any variations thereof are intended to cover non-exclusive inclusions.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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).

[0042] 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.

[0043] 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.

[0044] 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.

[0045] 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.

[0046] 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.

[0047] Based on the above, the present application example provides a piezoelectric resonant pressure sensor and compensation system.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] For example, Figure 1 A schematic diagram of the internal structure of a piezoelectric resonant pressure sensor provided as an example of this application, Figure 2This is a schematic diagram of the internal structure of another piezoelectric resonant pressure sensor provided as an example in this application. Figure 1 and Figure 2 The piezoelectric resonant pressure sensor 100 includes a resonant component 110, a piezoelectric component 120, a connecting component 130 and a pressure sensitive component 140. The resonant component 110 is provided with a resonant cavity 111. The piezoelectric component 120 is provided at one side of the resonant component 110. The connecting component 130 is connected to the side of the piezoelectric component 120 away from the resonant component 110, and the connecting component 130 is directly or indirectly connected to an external circuit. The pressure sensitive component 140 is provided at the side of the piezoelectric component 120 away from the resonant component 110, and the pressure sensitive component 140 is used to receive the pressure to be detected, and the pressure sensitive component 140 includes a pressure-bearing area. Along the direction from the resonant component 110 to the pressure-sensitive component 140, the projection of the resonant cavity 111 at least partially falls into the pressure-bearing area.

[0052] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the pressure sensitive component 140 can receive the pressure to be detected, and the pressure sensitive component 140 is connected to the piezoelectric component 120 through the connecting component 130, and the pressure to be detected can be transmitted to the piezoelectric component 120 through the pressure sensitive component 140 and the connecting component 130. Based on this, the piezoelectric component 120 and the pressure sensitive component 140 are arranged at intervals, and based on the characteristics of the piezoelectric component 120, the pressure to be detected can be detected.

[0053] The resonant component 110 includes a resonant cavity 111. The resonant component 110 is disposed on a side of the piezoelectric component 120 away from the connecting component 130. When the piezoelectric component 120 drives the resonant component 110 to vibrate, the space between the connecting component 130 and the piezoelectric component 120 and the resonant cavity 111 can provide a deformation space for the piezoelectric component 120. The piezoelectric component 120 can be directly or indirectly connected to an external circuit.

[0054] Next, the structure of the piezoelectric resonant pressure sensor 100 is described in detail.

[0055] The pressure sensitive component 140 may include only the pressure sensitive film 142 , or the pressure sensitive component 140 may include the pressure sensitive film 142 and other structures connected to the pressure sensitive film 142 .

[0056] In the case where the pressure sensitive component 140 includes only the pressure sensitive film 142, the pressure-bearing area may be the side of the pressure sensitive film 142 away from the resonance component 110. In the case where the pressure sensitive component 140 includes the pressure sensitive film 142 and other structures connected to the pressure sensitive film 142, the pressure-bearing area may also be an area formed by the pressure sensitive film 142 and other structures connected to the pressure sensitive film 142, which is not specifically limited in this example of the present application.

[0057] The pressure to be detected received by the pressure sensitive component 140 may be the pressure applied directly or indirectly to the pressure sensitive component 140 by the fluid, and the fluid may be liquid or gas, etc.

[0058] The direction of the pressure to be detected may be along the pressure sensitive component 140 toward the piezoelectric component 120 , the pressure to be detected may act perpendicularly on the pressure sensitive component 140 , and there may also be an angle between the direction of the pressure to be detected and the pressure sensitive component 140 .

[0059] The piezoelectric component 120 can be directly or indirectly connected to the side of the pressure sensitive component 140 away from the pressure area. The resonant component 110 is provided on the side of the piezoelectric component 120 away from the pressure sensitive component 140. The pressure to be detected acting on the pressure sensitive component 140 can be transmitted to the piezoelectric component 120 through the pressure sensitive component 140, and the pressure to be detected is detected by the piezoelectric component 120.

[0060] For example, the piezoelectric component 120 may include a piezoelectric layer 122 and an electrode. The piezoelectric layer 122 may be made of AlN, ScAlN, PZT (piezoelectric ceramic), ZnO, LiNbO 3 Due to the particularity of the piezoelectric film material, when the piezoelectric layer 122 receives pressure, two opposite sides of the piezoelectric layer 122 can generate a potential difference. By using the positive piezoelectric effect and the inverse piezoelectric effect of the piezoelectric layer 122, the vibration of the piezoelectric resonant pressure sensor 100 can be detected, and then the relevant parameters of the pressure to be detected can be obtained. The relevant parameters may include the numerical value of the pressure to be detected and the direction parameters of the pressure to be detected.

[0061] 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.

[0062] 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 120.

[0063] Along the direction from the resonant component 110 to the pressure sensitive component 140, at least part of the projection of the resonant cavity 111 falls into the pressure area. For example, the projection of the resonant cavity 111 may completely fall into the pressure area, in which case the geometric center of the projection of the resonant cavity 111 may overlap with the geometric center of the pressure area, or there may be a distance between the geometric center of the resonant cavity 111 and the geometric center of the pressure area.

[0064] For example, a projection of part of the resonant cavity 111 may fall into the compressed region, that is, the projection of the resonant cavity 111 partially overlaps with the compressed region.

[0065] The shape of the pressure-bearing region may be the same as the shape of the resonance cavity 111 , or the shape of the pressure-bearing region may be different from the shape of the resonance cavity 111 .

[0066] There may be one pressure-bearing area, or multiple pressure-bearing areas may be arranged at intervals. There may also be only one resonant cavity 111, or multiple resonant cavities 111 may be arranged, and this application example does not limit this.

[0067] The example of the present application does not make any specific limitation on the positional relationship between the resonant cavity 111 and the pressure area, as long as the projection of at least part of the resonant cavity 111 coincides with the projection of the pressure area, thereby ensuring that the pressure to be detected received by the pressure area can be transmitted to the piezoelectric component 120 through the resonant cavity 111, and the pressure to be detected can be detected by the piezoelectric component 120.

[0068] Based on the above, according to the piezoelectric resonant pressure sensor 100 provided in the example of this application, the pressurized area can receive the pressure to be detected, and the pressure to be detected can be transmitted to the piezoelectric component 120 through the pressure sensitive component 140 and the connecting component 130, and the pressure to be detected is detected through the characteristics of the piezoelectric component 120.

[0069] Since the piezoelectric component 120 is connected to one side of the pressure sensitive component 140 through the connecting component 130, the pressure-bearing area is spaced apart from the piezoelectric component 120, and since the resonant component 110 having the resonant cavity 111 is disposed on the side of the piezoelectric component 120 away from the connecting component 130, when the piezoelectric component 120 drives the resonant component 110 to vibrate, the space between the connecting component 130 and the piezoelectric component 120 and the resonant cavity 111 can provide deformation space for the piezoelectric component 120, thereby reducing the possibility of damage to the piezoelectric component 120 due to a large deformation amount caused by vibration.

[0070] When the possibility of damage to the piezoelectric component 120 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.

[0071] In addition, compared with the existing piezoelectric resonant pressure sensor 100 in which the resonant cavity 111 and the pressure-bearing area are staggered, the piezoelectric resonant pressure sensor 100 provided in the example of the present application has a projection of the resonant cavity 111 at least partially falling within the projection range of the pressure cavity 141 along the direction from the resonant film 112 to the pressure resonance component 110, which occupies less space and can 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.

[0072] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, along the direction from the resonant film 112 to the pressure resonance component 110 , the projection of the resonant cavity 111 falls within the projection range of the pressure-bearing region.

[0073] Compared with the existing piezoelectric resonant pressure sensor 100 in which the resonant cavity 111 and the pressure area are arranged in a staggered manner, the piezoelectric resonant pressure sensor 100 provided in the example of the present application has a projection of the resonant cavity 111 falling within the pressure area along the direction from the resonant film 112 to the pressure resonance component 110, and occupies less space. In this way, the volume of the piezoelectric resonant pressure sensor 100 can be further reduced, which is conducive to the miniaturization of the piezoelectric resonant pressure sensor 100 and the integrated development of the piezoelectric resonant pressure sensor 100.

[0074] Based on the piezoelectric resonant pressure sensor 100 disclosed in the above example, Figure 2 The internal structure diagram of a piezoelectric resonant pressure sensor 100 provided as an example of this application is shown in FIG. Figure 2 A pressure chamber 141 is provided on the side of the pressure sensitive component 140 away from the piezoelectric component 120 . The pressure chamber 141 is used to receive the pressure to be detected, and the pressurized area is located in the pressure chamber 141 .

[0075] The pressure chamber 141 can be formed in many ways.

[0076] Exemplarily, the pressure chamber 141 may be a cavity formed by removing the middle part of a block structure. The pressure sensitive film 142 may be a part of the block structure corresponding to the bottom of the pressure chamber 141 . The resonant substrate 143 may be a part of the block structure corresponding to the side wall of the pressure chamber 141 .

[0077] Exemplarily, the pressure chamber 141 may be a cavity formed by enclosing a plurality of structures. For example, the pressure sensitive component 140 includes a pressure sensitive film 142 and a resonant substrate 143, the resonant substrate 143 is disposed on a side of the pressure sensitive film 142 away from the piezoelectric component 120, a first through hole is disposed on the resonant substrate 143, the pressure sensitive film 142 closes the opening of the first through hole toward the resonant component 110, and the pressure sensitive film 142 cooperates with the first through hole to form the pressure chamber 141.

[0078] By setting up a resonant substrate 143, the resonant substrate 143 cooperates with the pressure sensitive film 142 to form a pressure chamber 141. The operator can control the gas or liquid or other fluid to apply pressure to the cavity wall of the pressure chamber 141. By setting up the pressure chamber 141, the force on the pressure sensitive film 142 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 141.

[0079] In summary, by setting the pressure chamber 141 , it is convenient for the operator to control the gas or liquid or other fluid to apply the pressure to be detected to the cavity wall of the pressure chamber 141 . By setting the pressure chamber 141 , the force on the pressure sensitive film 142 can be more concentrated.

[0080] Based on the piezoelectric resonant pressure sensor 100 disclosed in the above example, please refer to Figure 2 The pressure sensitive component 140 may include a pressure sensitive film 142 , a resonant substrate 143 and a second buried oxide layer 420 . The second buried oxide layer 420 is disposed between the pressure sensitive film 142 and the resonant substrate 143 . The pressure sensitive film 142 and the resonant substrate 143 are connected through the second buried oxide layer 420 .

[0081] The pressure sensitive component 140 is provided with a first through hole, which penetrates the resonant substrate 143 and the second buried oxide layer 420 . The pressure sensitive film 142 closes the opening of the first through hole toward the resonant component 110 . The pressure sensitive film 142 cooperates with the first through hole to form a pressure chamber 141 .

[0082] Alternatively, the first through hole passes through the resonant substrate 143 , the second buried oxide layer 420 closes the opening of the first through hole toward the resonant component 110 , and the second buried oxide layer 420 cooperates with the first through hole to form the pressure chamber 141 .

[0083] The opening of the first through hole toward the resonance component 110 can penetrate the second buried oxide layer 420, and at this time, the pressure sensitive film 142 can close the opening of the first through hole toward the resonance component 110. At this time, the pressure sensitive film 142, the second buried oxide layer 420 and the first through hole cooperate to form a pressure chamber 141.

[0084] The opening of the first through hole toward the resonance component 110 may also be located on the side of the second buried oxide layer 420 away from the resonance substrate 143. In this case, the second buried oxide layer 420 and the pressure sensitive film together seal the opening of the first through hole toward the resonance component 110. In this case, the second buried oxide layer 420 and the first through hole cooperate to form the pressure chamber 141.

[0085] The pressure sensitive film 142 and the resonant substrate 143 can both be made of silicon or other semiconductor materials. The second buried oxide layer 420 can be made of silicon oxide or other materials. The manufacturing material of the second buried oxide layer 420 can be different based on the manufacturing materials of the pressure sensitive film 142 and the resonant substrate 143. The specific setting of the second buried oxide layer 420 is not limited in this application example.

[0086] The present application example is described by taking the case where the pressure sensitive film 142 and the resonant substrate 143 are both made of silicon material and the second buried oxide layer 420 is made of silicon oxide material as an example. Compared with silicon material, silicon oxide material has better insulation and lower thermal conductivity.

[0087] The second buried oxide layer 420 can ensure the insulation between the pressure sensitive film 142 and the resonant substrate 143 , and can also ensure the insulation between the pressure component and the resonant component 110 , thereby ensuring the reliability of the piezoelectric resonant pressure sensor 100 .

[0088] The second 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.

[0089] Next, the specific structure of the piezoelectric component 120 is described in detail.

[0090] Based on the piezoelectric resonant pressure sensor 100 disclosed in the above example, Figure 3 for Figure 2 A partial enlarged view of the middle A. Figure 4 A schematic diagram of the resonance principle of a piezoelectric resonant pressure sensor provided for this application example, please refer to Figure 2 to Figure 4 The piezoelectric component 120 may include a first electrode layer, a piezoelectric layer 122, a second electrode layer, a connecting layer, and a lead electrode layer.

[0091] The side of the lead electrode layer facing away from the resonance component 110 can be connected to the connection component 130, and the side of the lead electrode layer facing the resonance component 110 is connected to the first electrode 121, the connection layer and the second electrode 123. The connection position between the lead electrode layer and the first electrode 121, the connection position between the lead electrode layer and the connection layer, and the connection position between the lead electrode layer and the second electrode 123 are spaced apart from each other.

[0092] The side of the connection layer facing the resonance component 110 is connected to the piezoelectric layer 122 and the first electrode 121, and the connection position of the connection layer and the piezoelectric layer 122 and the connection position of the connection layer and the second electrode 123 are spaced apart from each other. A portion of the piezoelectric layer 122 is disposed between the first electrode 121 and the second electrode 123, and the side of the second electrode 123 facing away from the piezoelectric layer 122 is connected to the resonance component 110.

[0093] By setting the lead electrode layer to include multiple lead electrodes, the lead electrode connected to the first electrode 121, the lead electrode connected to the connecting layer, and the lead electrode connected to the second electrode 123 are different lead electrodes. It is possible to achieve that the connection positions of the lead electrode layer and the first electrode 121, the connection positions of the lead electrode layer and the connecting layer, and the connection positions of the lead electrode layer and the second electrode 123 are spaced apart from each other.

[0094] By setting the connection layer to include multiple connection structures, and the connection structure connected to the piezoelectric layer 122 and the connection structure connected to the first electrode 121 are different connection structures, the connection position between the connection layer and the piezoelectric layer 122 and the connection position between the connection layer and the second electrode 123 can be spaced apart from each other.

[0095] The second electrode layer may be composed of at least one second electrode 123. The second electrode layer may include only one second electrode 123, or may include a plurality of second electrodes 123 disposed at intervals.

[0096] The second electrode 123 may be a conductive layer disposed on one side of the resonance component 110 , and the second electrode 123 may be grounded.

[0097] A piezoelectric layer 122 may be disposed on a side of the second electrode layer facing away from the resonance component 110 .

[0098] The first electrode layer is disposed on a side of the piezoelectric layer 122 away from the second electrode layer. The first electrode layer may include at least two first electrodes 121 .

[0099] Exemplarily, the connection layer may include a first connection structure 1241 and a second connection structure 1251. The second electrode layer includes at least one second electrode 123, the first electrode layer includes at least two first electrodes 121 spaced apart, the lead electrode layer includes a second lead electrode 125 and at least two first lead electrodes 124 spaced apart, the connection layer includes a second connection portion 134 and at least two first connection portions 133 spaced apart, and the connection assembly 130 includes a first connection electrode 131, a second connection electrode 132, a first connection portion 133, and a second connection portion 134.

[0100] One side of the first lead electrode 124 is connected to the first electrode 121, and the other side of the first lead electrode 124 is connected to the first connection electrode 131 through the first connection portion 133. The first connection electrode 131 is directly or indirectly connected to a first part of the external circuit. One side of the second lead electrode 125 is connected to the second electrode 123, and the other side of the second lead electrode 125 is connected to the second connection electrode 132 through the second connection portion 134. The second connection electrode 132 is directly or indirectly connected to a second part of the external circuit.

[0101] In the present example, the first electrode layer may include at least two first electrodes 121 spaced apart from each other, and the first electrode 121 may include at least one driving electrode and at least one detecting electrode. The driving electrode is used to drive the piezoelectric layer 122 to vibrate, and the detecting electrode is used to detect the vibration of the piezoelectric layer 122.

[0102] Next, the connection methods of different electrodes to external circuits are described in detail.

[0103] There are many ways to connect the first electrode 121 to the external circuit. The following is an exemplary description of the way to connect the first electrode 121 to the external circuit. The first electrode 121 and the external circuit may also include other ways to connect.

[0104] The number of the first connection parts 133 may be equal to and correspond to the number of the first electrodes 121 , or may be greater than the number of the first electrodes 121 . The number of the first connection electrodes 131 may be equal to and correspond to the number of the first connection parts 133 .

[0105] Please refer to Figure 2 and Figure 3 , the first connection electrode 131 can be arranged on the side of the pressure sensitive component 140 facing the piezoelectric component 120. At this time, one end of the first lead electrode 124 is connected to the first electrode 121, so as to lead the first electrode 121 to a position outside the piezoelectric component 120, so as to facilitate connection with the connection component 130. The other end of the first lead electrode 124 can be connected to the first connection electrode 131 through the first connection portion 133, and the first connection electrode 131 can be connected to an external circuit on the side of the pressure sensitive component 140 facing the piezoelectric component 120, so as to realize the connection between the first electrode 121 and the external circuit.

[0106] There may be multiple connection modes between the second electrode 123 and the external circuit. The following only describes the connection mode between the second electrode 123 and the external circuit as an example, and the second electrode 123 and the external circuit may also include other connection modes.

[0107] For example, please refer to Figure 2 , the second connection electrode 132 can be arranged on the side of the pressure sensitive component 140 facing the piezoelectric component 120. The piezoelectric component 120 can be provided with a first connection hole 510. The second electrode 123 can be a conductive layer arranged on one side of the resonance component 110. One end of the second lead electrode 125 can be inserted into the first connection hole 510 and connected to the second electrode 123, and the other end of the second lead electrode 125 is connected to the second connection electrode 132 through the second connection portion 134. The second connection electrode 132 can be connected to an external circuit on the side of the pressure sensitive component 140 facing the piezoelectric component 120.

[0108] For example, Figure 5 For the internal structure diagram of another piezoelectric resonant pressure sensor provided as an example of this application, please refer to Figure 5 , the pressure sensitive component 140 may also be provided with a second connection hole 520, and the second connection hole 520 may be provided through the pressure sensitive component 140. The second connection electrode 132 may be provided through the second connection hole 520, so that the end of the second connection electrode 132 away from the second connection portion 134 can be exposed from the pressure sensitive component 140, so as to facilitate the connection of the second connection electrode 132 with an external circuit. At this time, the piezoelectric component 120 may be provided with a first connection hole 510. The second electrode 123 may be a conductive layer provided on one side of the resonant component 110. One end of the second lead electrode 125 may be provided through the first connection hole 510 to be connected to the second electrode 123, and the other end of the second lead electrode 125 may be connected to the second connection electrode 132 through the second connection portion 134. The second connection electrode 132 may be connected to an external circuit on the side of the pressure sensitive component 140 facing the piezoelectric component 120.

[0109] The second electrode 123 may have the same or different shapes as the first electrode 121. This application example only takes the first electrode 121 as an example for description. For example, the first electrode 121 may be cylindrical, prism or any other regular shape, or may be irregular.

[0110] At least one second connection electrode 132 may be provided, or a plurality of second connection electrodes 132 may be provided. The plurality of second connection electrodes 132 may be connected to different positions of the second electrode 123 .

[0111] The shapes of the first lead electrode 124 and the second lead electrode 125 may be the same or different. Here, only the first lead electrode 124 is taken as an example for description.

[0112] Exemplarily, the first lead electrode 124 may be a protrusion disposed on the pressure sensitive component 140 toward the piezoelectric component 120 , and the first lead electrode 124 may be in a prismatic structure, a prism structure, a cylindrical structure, a truncated cone structure, a stepped structure or other structures.

[0113] The first connection structure 1241 is disposed between the piezoelectric layer 122 and the first lead electrode 124 , and the first connection structure 1241 connects the piezoelectric layer 122 and the first lead electrode 124 . The second connection structure 1251 is disposed between the piezoelectric layer 122 and the second lead electrode 125 , and the second connection structure 1251 connects the piezoelectric layer 122 and the second lead electrode 125 .

[0114] The structure of the first connection structure 1241 is similar to that of the second connection structure 1251 , and they play similar functions. Next, only the first connection structure 1241 is taken as an example for description.

[0115] The first connection structure 1241 may be cylindrical, prism-shaped, truncated cone-shaped or other shapes. At least one first connection structure 1241 may be provided, or two, three, or even more first connection structures 1241 may be provided.

[0116] The manufacturing material of the first connection structure 1241 can be silicon dioxide, silicon, metal, etc., and this example of the application does not make any specific limitation on this.

[0117] Based on the above, since one side of the first connecting structure 1241 is connected to the pressure sensitive component 140, and the other side of the first connecting structure 1241 is connected to the piezoelectric layer 122, the pressure to be detected acting on the pressure sensitive film 142 can be transmitted to the piezoelectric component 120 and the resonant component 110 through the first connecting structure 1241, and converted into stress on the piezoelectric component 120 and the resonant component 110, thereby causing a change in the structural resonance frequency.

[0118] The shapes of the first connection electrode 131 and the second connection electrode 132 may be the same or different. Here, only the first connection electrode 131 is taken as an example for description.

[0119] Exemplarily, the first connecting electrode 131 may be a protrusion disposed on the pressure sensitive component 140 and facing the piezoelectric component 120 , and the first connecting electrode 131 may be in a prismatic structure, a prism structure, a cylindrical structure, a truncated cone structure or other structures.

[0120] The first electrode 121 , the second electrode 123 , the first lead electrode 124 , the second lead electrode 125 , the first connection electrode 131 , and the second connection electrode 132 may all be made of a conductive material, such as molybdenum, aluminum, copper, or gold.

[0121] The first connection part 133 and the second connection part 134 can also be made of metal materials, such as germanium, tin, gold, etc., as long as the first connection part 133 can be connected to the first lead electrode 124 and the first connecting electrode 131, and the second connection part 134 can be connected to the second lead electrode 125 and the second connecting electrode 132. The example of this application does not limit the specific implementation method of the first electrode 121, the second electrode 123, the first lead electrode 124, the second lead electrode 125, the first connecting electrode 131, the second connecting electrode 132, the first connection part 133 and the second connection part 134.

[0122] 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.

[0123] 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 need to set up an additional detection circuit. Only the piezoelectric component 120 is needed to detect the pressure to be detected. The structure is simpler and the manufacturing cost is lower.

[0124] Figure 6 A schematic diagram of the working principle of a piezoelectric resonant pressure sensor provided in this application example, referring to Figure 6 , the connection structure can change the direction of action of the pressure to be detected.

[0125] Exemplarily, the pressure to be detected acts on the pressure sensitive film 142 in a direction perpendicular to the pressure sensitive film 142. The pressure to be detected acting on the pressure sensitive film 142 can be transmitted to the piezoelectric component 120 through the connecting structure. The connecting structure can convert the pressure to be detected perpendicular to the pressure sensitive film 142 into a working stress having an angle between the direction of action and the direction of action of the pressure to be detected.

[0126] In summary, the connecting structure can directly or indirectly connect the pressure sensitive film 142 and the piezoelectric component 120, 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 120 is smaller, thereby reducing the possibility of damage to the piezoelectric component 120, improving the pressure-bearing capacity of the piezoelectric layer 122, expanding the detection range of the piezoelectric resonant pressure sensor 100, and ensuring the linearity of the piezoelectric resonant pressure sensor 100 within the pressure detection range.

[0127] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, please refer to Figure 2 and Figure 3 The first connection structure 1241 and the second connection structure 1251 can be anchored on one side close to the pressure sensitive film 142. The distance between the anchor and the piezoelectric component 120 is a first distance, and the distance between the anchor and the pressure sensitive film 142 is a second distance. The first distance is greater than the second distance.

[0128] The anchor point may be the first connection structure 1241 , and the anchor point may also be the main stress point of the second connection structure 1251 .

[0129] By setting the first distance to be greater than the second distance, the piezoelectric layer 122, the pressure sensitive film 142 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 connection structure 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.

[0130] Next, please refer to Figure 2 to Figure 4 , the principle of the piezoelectric resonant pressure sensor 100 is further introduced in combination with the specific structure of the piezoelectric component 120.

[0131] The resonant component 110 and the piezoelectric component 120 in the resonant component 110 cooperate with each other to form a piezoelectric resonator.

[0132] When any of the first electrodes 121 receives a voltage, stress is generated in the piezoelectric layer 122 based on the inverse piezoelectric effect of the piezoelectric layer 122. At this time, since the neutral layer of the piezoelectric layer 122 deviates from the geometric center position of the piezoelectric layer 122, the piezoelectric layer 122 will be deformed, and the deformation of the piezoelectric layer 122 drives the entire piezoelectric resonator to deform.

[0133] When an alternating voltage having the same resonant frequency as the piezoelectric resonator is applied to any first electrode 121, the entire structure will resonate, and the resonant frequency is:

[0134]

[0135] 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.

[0136] When the pressure chamber 141 receives the pressure to be detected, the pressure sensitive film 142 will be deformed and generate working stress under the action of the pressure to be detected. The connection structure can transfer the deformation and working stress of the pressure sensitive film 142 to the piezoelectric resonator, specifically to the piezoelectric layer 122. During the transmission process of the connection structure, the connection structure can change the direction of action of the pressure to be detected, reducing the possibility of damage to the resonant film 112. 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.

[0137] Since the piezoelectric resonator is provided with at least two first electrodes 121, when one of the first electrodes 121 drives the piezoelectric layer 122 to vibrate, the other first electrode 121 detects the vibration of the piezoelectric resonator. The first electrode 121 receiving the voltage may be a driving electrode, and the first electrode 121 detecting the vibration may be a detecting electrode.

[0138] 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.

[0139] 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:

[0140]

[0141] 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.

[0142] When the piezoelectric layer 122 is deformed, the part of the piezoelectric layer 122 close to the resonance film 112 is squeezed by the pressure to be detected, and the part of the piezoelectric layer 122 away from the resonance film 112 is stretched by the pressure to be detected. On the cross section of the piezoelectric layer 122, the transition layer between the stretched part of the piezoelectric layer 122 and the squeezed part of the piezoelectric layer 122, which is neither stretched nor compressed and has almost zero stress, is the above-mentioned neutral layer.

[0143] 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.

[0144] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the piezoelectric component 120 may further include a seed layer, which is disposed between the piezoelectric component 120 and the resonant film 112 , and specifically between the second electrode 123 and the resonant film 112 .

[0145] By providing the seed layer, the working performance of the piezoelectric component 120 can be guaranteed, thereby ensuring the working performance of the piezoelectric resonant pressure sensor 100.

[0146] Next, the specific structure of the resonance component 110 is described.

[0147] Based on the piezoelectric resonant pressure sensor 100 disclosed in the above example, the resonant component 110 may include a resonant substrate 113 and a resonant film 112 connected to each other, the resonant substrate 113 is provided with a resonant groove on one side facing the resonant film 112, and the resonant film 112 cooperates with the resonant groove to form a resonant cavity 111. The resonant film 112 is connected to the piezoelectric component 120 on one side facing away from the resonant substrate 113.

[0148] The resonant film 112 can completely close the notch of the resonant groove, and cooperate with the resonant groove to form a sealed resonant cavity 111. Exemplarily, at this time, the resonant film 112 can be a complete planar structure.

[0149] The resonant film 112 may also not close the notch of the resonant groove, and cooperate with the resonant groove to form a resonant cavity 111 with an opening. By way of example, at this time, the resonant film 112 may be provided with at least one through hole, which may be a circular hole, a square hole, or a hole of other shapes. The example of this application does not limit the specific shape of the through hole.

[0150] The resonant substrate 113 and the resonant film 112 may be integrally formed, and the resonant substrate 113 and the resonant film 112 may also be connected together by bonding or other means.

[0151] When the resonant substrate 113 and the resonant film 112 are integrally formed, the resonant cavity 111 can be disposed on the resonant substrate 113 , and the resonant film 112 can close the cavity opening of the resonant cavity 111 .

[0152] The resonant substrate 113 and the resonant film 112 may be connected by anodic bonding, fusion bonding or other bonding methods.

[0153] Based on the above, since the resonant cavity 111 is disposed on one side of the piezoelectric component 120 , the resonant cavity 111 can provide a vibration space for the vibration of the piezoelectric component 120 , thereby reducing the possibility of damage to the piezoelectric component 120 due to deformation of the piezoelectric component 120 caused by vibration.

[0154] In the piezoelectric resonant pressure sensor 100 mentioned in the above example, the cavity can be kept in vacuum, or the cavity can be filled with a medium.

[0155] For example, the cavity of the piezoelectric resonant pressure sensor 100 may be kept in a vacuum, in which case 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.

[0156] Exemplarily, a medium may also be filled in the cavity of the piezoelectric resonant pressure sensor 100. In this case, the piezoelectric resonant pressure sensor 100 may be a relative pressure sensor.

[0157] Relative pressure sensors measure relative pressure. Therefore, the measurement result of relative pressure sensors is relative to atmospheric pressure. Therefore, relative pressure sensors can be used to measure the difference in relative pressure.

[0158] 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.

[0159] Based on the piezoelectric resonant pressure sensor 100 disclosed in the above example, please refer to Figure 5 The resonant component 110 may further include a first buried oxide layer 320 , and the resonant substrate 113 and the resonant film 112 are connected via the first buried oxide layer 320 .

[0160] The first buried oxide layer 320 may be a structure formed during the bonding process between the resonance substrate 113 and the resonance film 112 , or the first buried oxide layer 320 may be a structure intentionally disposed between the resonance substrate 113 and the resonance film 112 .

[0161] The resonant film 112 and the resonant substrate 113 can both be made of silicon or other semiconductor materials. The first buried oxide layer 320 can be made of silicon oxide or other materials. The manufacturing material of the first buried oxide layer 320 can be different based on the different manufacturing materials of the resonant film 112 and the resonant substrate 113. The specific setting of the first buried oxide layer 320 is not limited in the example of this application.

[0162] The present application example is described by taking the case where both the resonant film 112 and the resonant substrate 113 are made of silicon material and the first buried oxide layer 320 is made of silicon oxide material as an example. Compared with silicon material, silicon oxide material has better insulation and lower thermal conductivity.

[0163] The first buried oxide layer 320 can ensure the insulation between the resonant film 112 and the resonant substrate 113 , and can also ensure the insulation between the pressure component and the resonant component 110 , thereby ensuring the reliability of the piezoelectric resonant pressure sensor 100 .

[0164] The first buried oxide layer 320 can also reduce the influence of temperature in environmental factors on the piezoelectric resonant pressure sensor 100 , thereby ensuring the detection accuracy of the resonant pressure sensor.

[0165] 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.

[0166] Exemplarily, the present application provides a compensation system 200, Figure 7 For a schematic diagram of the compensation system provided for this application example, please refer to Figure 7The compensation system 200 may include an integrated driving component, a detection component, and at least two piezoelectric resonant pressure sensors mentioned in the above embodiments, and the at least two piezoelectric resonant pressure sensors include at least one pressure sensor 210 and at least one compensation sensor 220.

[0167] When one pressure sensor 210 is provided, only one compensation sensor 220 may be provided, or a plurality of compensation sensors 220 may be provided.

[0168] 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.

[0169] 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.

[0170] 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 is connected to the driving electrode of the pressure sensor 210 and the driving electrode of the compensation sensor 220, and the driving component is used to drive the detection sensor and the compensation sensor 220 to vibrate. The detection component is connected to the detection electrode of the pressure sensor 210 and the detection electrode of the compensation sensor 220. The detection component is used to detect the resonant frequency of the pressure sensor 210 and the compensation sensor 220.

[0171] Since the pressure sensor 210 and the compensation sensor 220 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 210 and the compensation sensor 220, so that the resonant films of the pressure sensor 210 and the compensation sensor 220 can have the same output based on the influence of environmental factors.

[0172] Based on this, when the detection component 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.

[0173] Figure 8 For a schematic diagram of the working process of a compensation system 200 provided as an example of this application, please refer to Figure 8 , the working process of the compensation sensor 220 is as follows:

[0174] S101 , the driving component is used to drive the pressure sensor 210 and the compensation sensor 220 .

[0175] S102 , the detection component 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 .

[0176] 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.

[0177] S104, the calculation module may also calculate the pressure value of the pressure to be detected based on the resonance frequency.

[0178] The calculation module may be a part of the detection component, or may be a module independent of the detection component, which is not limited in this application example.

[0179] 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 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 resonance component. The example of this application does not limit the specific structures of the pressure sensor 210 and the compensation sensor 220.

[0180] In summary, according to the compensation system 200 provided in the example of the present application, when the detection component 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.

[0181] 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 resonant assembly having a resonant cavity; A piezoelectric component is disposed on one side of the resonant component; A connecting component connected to a side of the piezoelectric component away from the resonant component, the connecting component being directly or indirectly connected to an external circuit; A pressure sensitive component, disposed on a side of the connecting component away from the piezoelectric component, the pressure sensitive component is used to receive the pressure to be detected, and the pressure sensitive component includes a pressure-receiving area; Wherein, along the direction from the resonant component to the pressure sensitive component, the projection of the resonant cavity at least partially falls into the pressure area.

2. The piezoelectric resonant pressure sensor according to claim 1, characterized in that: A pressure chamber is provided on a side of the pressure sensitive component facing away from the piezoelectric component. The pressure chamber is used to receive the pressure to be detected, and the pressurized area is located in the pressure chamber.

3. The piezoelectric resonant pressure sensor according to claim 2, characterized in that: The pressure sensitive component includes a pressure sensitive film and a resonant substrate. The resonant substrate is arranged on a side of the pressure sensitive film away from the piezoelectric component. The resonant substrate is provided with a first through hole. The pressure sensitive film closes the opening of the first through hole toward the resonant component. The pressure sensitive film cooperates with the first through hole to form the pressure chamber.

4. The piezoelectric resonant pressure sensor according to claim 2, characterized in that: The pressure sensitive component includes a pressure sensitive film, a resonant substrate and a second buried oxide layer, wherein the second buried oxide layer is disposed between the pressure sensitive film and the resonant substrate, the pressure sensitive film and the resonant substrate are connected via the second buried oxide layer, and the pressure sensitive component is provided with a first through hole. The first through hole penetrates the resonant substrate and the buried oxide layer, the pressure sensitive film closes the opening of the first through hole toward the resonant component, and the pressure sensitive film cooperates with the first through hole to form the pressure chamber; or, The first through hole penetrates the resonant substrate, the second buried oxide layer seals the opening of the first through hole toward the resonant component, and the second buried oxide layer cooperates with the first through hole to form the pressure chamber.

5. The piezoelectric resonant pressure sensor according to any one of claims 1 to 4, characterized in that: The resonant component comprises a resonant substrate and a resonant film connected to each other, a resonant groove is provided on a side of the resonant substrate facing the resonant film, and the resonant film cooperates with the resonant groove to form the resonant cavity; The side of the resonance film facing away from the resonance substrate is connected to the piezoelectric component.

6. The piezoelectric resonant pressure sensor according to claim 5, characterized in that: The resonant component further includes a first buried oxide layer, and the resonant substrate and the resonant film are connected via the first buried oxide layer.

7. The piezoelectric resonant pressure sensor according to any one of claims 1 to 4, characterized in that: The piezoelectric component includes a first electrode layer, a piezoelectric layer, a second electrode layer, a connecting layer and a lead electrode layer; The side of the lead electrode layer facing away from the resonance component is connected to the connection component, and the side of the lead electrode layer facing the resonance component is connected to the first electrode, the connection layer, and the second electrode, and the connection position of the lead electrode layer and the first electrode, the connection position of the lead electrode layer and the connection layer, and the connection position of the lead electrode layer and the second electrode are spaced from each other; The connecting layer is connected to the piezoelectric layer and the first electrode at one side facing the resonant component, and the connecting position between the connecting layer and the piezoelectric layer and the connecting position between the connecting layer and the first electrode are spaced apart from each other; A portion of the piezoelectric layer is disposed between the first electrode and the second electrode, and a side of the second electrode facing away from the piezoelectric layer is connected to the resonant component.

8. The piezoelectric resonant pressure sensor according to claim 7, characterized in that: The second electrode layer includes at least one second electrode, the first electrode layer includes at least two first electrodes spaced apart, the lead electrode layer includes a second lead electrode and at least two first lead electrodes spaced apart, the connection layer includes a second connection portion and at least two first connection portions spaced apart, and the connection assembly includes a first connection electrode, a second connection electrode, a first connection portion, and a second connection portion; One side of the first lead electrode is connected to the first electrode, the other side of the first lead electrode is connected to the first connection electrode through the first connection portion, and the first connection electrode is directly or indirectly connected to a first portion of the external circuit; One side of the second lead electrode is connected to the second electrode, the other side of the second lead electrode is connected to the second connection electrode through the second connection portion, and the second connection electrode is directly or indirectly connected to the second part of the external circuit.

9. 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 8, 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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