Piezoelectric resonant pressure sensor, compensation system and preparation method

Abstract

The invention provides a piezoelectric resonant pressure sensor, a compensation system and a preparation method, and relates to the technical field of sensors and sensor manufacturing. The piezoelectric resonant pressure sensor comprises a piezoelectric assembly, a resonant assembly and a pressure sensitive assembly. The resonant component is connected to one side of the piezoelectric component, and a resonant cavity is formed in the side, away from the piezoelectric component, of the resonant component. The pressure sensitive assembly is arranged on the side, away from the piezoelectric assembly, of the resonance assembly, a pressure cavity is formed in the side, away from the resonance assembly, of the pressure sensitive assembly, and the pressure cavity is used for receiving to-be-detected pressure. Wherein the piezoelectric resonant pressure sensor is provided with at least one first groove, the first groove is arranged in the resonant component, and the projection of at least part of the first groove falls into the projection range of the resonant cavity along the direction from the piezoelectric component to the resonant component. According to the piezoelectric resonant pressure sensor provided by the embodiment of the invention, the detection sensitivity and the detection precision of the piezoelectric resonant pressure sensor can be improved.

Description

Technical Field

[0001] The present application relates to the technical field of sensors and sensor manufacturing, and in particular to a piezoelectric resonant pressure sensor, a compensation system and a preparation method. 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 technical fields with high precision requirements and harsh environments, such as aerospace, petroleum, etc.

[0005] Based on the structure of the existing piezoelectric resonant pressure sensor, the detection sensitivity of the piezoelectric resonant pressure sensor is low. Summary of the invention

[0006] The present application provides a piezoelectric resonant pressure sensor, which can improve the detection sensitivity of the piezoelectric resonant pressure sensor and further improve the detection accuracy 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 electrically connected to an external circuit. The resonant component is connected to one side of the piezoelectric component, and a resonant cavity is provided on the side of the resonant component facing away from the piezoelectric component. The pressure-sensitive component is provided on the side of the resonant component facing away from the piezoelectric component, and a pressure cavity is provided on the side of the pressure-sensitive component facing away from the resonant component, and the pressure cavity is used to receive the pressure to be detected. Among them, the piezoelectric resonant pressure sensor is provided with at least one first groove, and the first groove is provided in the resonant component, and along the direction of the piezoelectric component toward the resonant component, at least part of the projection of the first groove falls within the projection range of the resonant cavity.

[0008] 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 is separated from the pressure chamber that receives the pressure to be detected. And since the resonant component is provided with a resonant cavity. In the case where the piezoelectric component drives the resonant component to vibrate, the resonant cavity can provide a deformation space for the piezoelectric component, thereby reducing the possibility of the piezoelectric component being damaged due to a large deformation amount caused by vibration.

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

[0010] In addition, when the pressure to be detected is transmitted to the piezoelectric component through the resonant component, the structure of the resonant component connected between the piezoelectric component and the pressure sensitive component may deform under the action of the pressure to be detected. By setting the first groove, a deformation space can be provided for the structure of the resonant component to deform.

[0011] Compared with the prior art in which the resonant component is a block structure, in the example of the present application, the first groove is provided in the resonant component. Therefore, the first groove can divide the resonant component into a plurality of spaced structures. The resonant component is more likely to deform under the action of the pressure to be detected, thereby improving the detection sensitivity of the piezoelectric resonant pressure sensor, and further improving the detection accuracy of the piezoelectric resonant pressure sensor.

[0012] In some possible implementations, a plurality of first grooves are provided, and the plurality of first grooves are arranged at intervals, and a deformation structure is formed between two adjacent first grooves.

[0013] In the example of the present application, since there are multiple first grooves and a deformation structure is formed between two adjacent first grooves, the contact area between the deformation structure and the pressure sensitive component is smaller, and the deformation structure is more likely to deform, which can further improve the detection sensitivity and detection accuracy of the piezoelectric resonant pressure sensor.

[0014] In some possible implementations, the plurality of first grooves are evenly arranged.

[0015] In the example of the present application, by arranging multiple first grooves evenly, the deformation amplitudes of different deformation structures under the action of the same pressure to be detected can be relatively similar, and thus the deformation amounts transmitted to the piezoelectric component by different deformation structures can be relatively similar, thereby ensuring the detection accuracy of the piezoelectric resonant pressure sensor for the detection pressure.

[0016] In some possible implementations, the first groove includes a first sub-groove and a second sub-groove that are connected to each other, and the second sub-groove is connected to the resonant cavity.

[0017] Based on the above, the first groove includes a first sub-groove and a second sub-groove that are connected to each other. By setting the relative position relationship between the first sub-groove and the second sub-groove, the cross-sectional area of ​​the deformable structure can be made smaller, so that the deformation amplitude of the deformable structure under the same pressure to be detected is larger, which is convenient for improving the detection sensitivity of the piezoelectric resonant pressure sensor. Based on this, under the action of different pressures to be detected, the deformation amplitude of the deformable structure will be relatively different, which is convenient for improving the detection accuracy of the piezoelectric resonant pressure sensor.

[0018] In some possible implementations, along the direction from the piezoelectric component to the resonant component, the projection of part of the first groove falls within the projection range of the resonant cavity. The first groove is arranged between the piezoelectric component and the pressure sensitive component. Alternatively, the first groove is arranged on a side of the resonant component away from the pressure sensitive component, and the notch of the first groove is opened away from the pressure sensitive component.

[0019] The first groove mentioned in the example of the present application can maintain a distance between the resonant base and the deformable structure, thereby reducing the cross-sectional area of ​​the deformable structure. During the transmission of the pressure to be detected, the deformation amplitude of the deformable structure is larger, thereby improving the detection sensitivity and detection accuracy of the piezoelectric resonant pressure sensor.

[0020] In some possible implementations, the center lines of the plurality of first grooves intersect at the intersection. The piezoelectric resonant pressure sensor is provided with at least one second groove, the second groove is provided at one end of the first groove away from the intersection, and the second groove is connected to the first groove.

[0021] Based on the above, by setting the center lines of multiple first grooves to intersect at the intersection, and setting the second groove on the side of the first groove away from the intersection, the second groove is connected to the first groove. Based on this, the cross-sectional area of ​​the deformation structure between any two first grooves can be further reduced, so that the deformation structure is easier to deform under the action of the pressure to be detected, thereby improving the detection sensitivity and detection accuracy of the piezoelectric resonant pressure sensor.

[0022] In some possible implementations, along the direction from the piezoelectric component to the resonant component, the projection of the second groove is spaced from the projection of the resonant cavity. A deformation structure is formed between the second groove, the first groove, and the resonant cavity, and a resonant film is provided on the side of the deformation structure facing the piezoelectric component, and the resonant film cooperates with the deformation structure to form a resonant cavity.

[0023] Since a pressure-sensitive film is arranged on one side of the deformation structure and a piezoelectric component is arranged on the other side of the deformation structure, the pressure to be detected acting on the pressure-sensitive film can be transmitted to the piezoelectric component through the deformation structure, and converted into stress on the piezoelectric component and the resonant component, thereby causing the structural resonant frequency to change. Since the resonant cavity is arranged on one side of the piezoelectric component, the resonant cavity can provide a vibration space for the vibration of the piezoelectric component, reducing the possibility of damage to the piezoelectric component due to deformation caused by vibration.

[0024] The deformation structure can connect the pressure-sensitive film and the piezoelectric component, and the deformation structure can change the direction of the pressure to be detected, so that the pressure to be detected acting vertically on the piezoelectric component is smaller, further reducing the possibility of damage to the piezoelectric component, improving the pressure-bearing capacity of the resonant film, further expanding the detection range of the piezoelectric resonant pressure sensor, and ensuring the linearity of the piezoelectric resonant pressure sensor within the pressure detection range.

[0025] In some possible implementations, the piezoelectric resonant pressure sensor further includes a cover, wherein 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.

[0026] In a vacuum environment, the cover can be used to encapsulate a piezoelectric resonator, which may include a resonant component and a piezoelectric component. The cover can be disposed on a side of the piezoelectric component away from the resonant component to isolate the piezoelectric component from the atmospheric environment, thereby ensuring that the piezoelectric component is in a vacuum environment when working, thereby increasing the value corresponding to the quality factor of the piezoelectric resonant pressure sensor and ensuring the working performance of the piezoelectric resonant pressure sensor.

[0027] The second aspect of the present application provides a method for preparing a piezoelectric resonant pressure sensor, which is applicable to the piezoelectric resonant pressure sensor mentioned in any of the above examples. The method is used to process a CSOI wafer into a piezoelectric resonant pressure sensor. The CSOI wafer includes a device layer, a buried oxide layer and a substrate layer. The substrate layer is provided with a resonant cavity, and the device layer closes the opening of the resonant cavity.

[0028] The method comprises: taking a CSOI wafer, processing a piezoelectric component on the side of the device layer away from the buried oxide layer, processing a pressure cavity on the side of the substrate layer away from the buried oxide layer, and processing a first groove on the side of the piezoelectric component away from the device layer, wherein the first groove is connected to the resonant cavity.

[0029] The third 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.

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

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

[0032] Figure 2 A top view of a piezoelectric resonant pressure sensor provided as an example of the present application.

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

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

[0035] Figure 5 for Figure 2 Cross-sectional view along CC.

[0036] Figure 6 for Figure 2 Diagram of the electrode arrangement of the structure shown.

[0037] Figure 7 for Figure 6 Cross-sectional view along DD.

[0038] Figure 8 A schematic diagram of the working principle of a piezoelectric resonant pressure sensor provided as an example in this application.

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

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

[0041] Fig.11 A schematic flow chart of a method for preparing a piezoelectric resonant pressure sensor provided as an example in this application.

[0042] Fig.12 A schematic diagram of the structure of an unprocessed CSOI wafer provided as an example in this application.

[0043] Fig.13 A schematic diagram of a structure in which a piezoelectric component is deposited on the side of a device layer facing away from a buried oxide layer is provided as an example of the present application.

[0044] Fig.14 A method based on Fig.13 Schematic diagram of the structure of the piezoelectric component after processing.

[0045] Fig.15 A method based on Fig.14 Schematic diagram of a structure in which a protective layer is provided on a side of a piezoelectric component away from a device layer.

[0046] Fig.16 A method based on Fig.15 Schematic diagram of the structure of processing the second connecting hole from the protective layer.

[0047] Fig.17 A method based on Fig.16 or Fig.15 Schematic diagram of the structure of processing the first connecting hole from the protective layer.

[0048] Fig.18 A method based on Fig.17 Schematic diagram of the structure of depositing a lead electrode layer on the side of the protection layer away from the device layer.

[0049] Fig.19 A method based on Fig.18 Schematic diagram of the structure for processing the lead electrode layer.

[0050] Fig. 20 A method based on Fig.19 Schematic diagram of the structure of processing the pressure cavity on the side of the substrate layer away from the device layer.

[0051] Fig.21 A method based on Fig. 20 Schematic diagram of the structure of processing the second groove from the protective layer.

[0052] Fig. 22 A schematic diagram of the structure of a glass wafer provided as an example of this application.

[0053] Fig.23 A schematic diagram of a structure for processing a Ge layer on a glass wafer provided as an example of this application.

[0054] Fig.24 A method based on Fig.23 Structural schematic diagram of processing the second connecting piece.

[0055] Fig.25 A schematic diagram of a structure for machining a cavity on a glass wafer to form a cover is provided as an example of the present application.

[0056] Fig.26 A schematic diagram of a structure in which an adsorption structure is provided inside a cover provided as an example of the present application.

[0057] Fig. 27 A schematic diagram of a structure in which a cover is connected to the side of a protective layer facing away from the piezoelectric layer, provided as an example of the present application.

[0058] Fig.28 A schematic diagram of the structure of a compensation system provided for the example of this application.

[0059] Fig.29 A schematic diagram of the working process of a compensation system provided as an example of this application.

[0060] Description of reference numerals:

[0061] 100, piezoelectric resonant pressure sensor; 110, piezoelectric component; 111, first lead electrode; 1111, first connection hole; 112, second lead electrode; 1121, second connection hole; 113, first electrode; 114, piezoelectric layer; 115, second electrode; 120, resonant component; 121, resonant cavity; 122, resonant film; 123, resonant substrate; 130, pressure sensitive component; 131, pressure cavity; 132, pressure sensitive film; 133, resonant substrate; 140, first groove; 141, The first sub-groove; 142, the second sub-groove; 150, the deformation structure; 160, the cover; 161, the adsorption structure; 162, the first connecting member; 163, the second connecting member; 170, the second groove; 171, the lead bridge; 172, the beam structure; 180, the protective layer; 200, the compensation system; 210, the pressure sensor; 220, the compensation sensor; 230, the driving component; 240, the detection component; 310, the device layer; 320, the buried oxide layer; 330, the substrate layer; 340, the lead electrode layer; 400, the glass wafer. DETAILED DESCRIPTION

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] 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).

[0069] 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.

[0070] Based on the above, the present application example provides a piezoelectric resonant pressure sensor, a compensation system and a preparation method.

[0071] 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.

[0072] The piezoelectric resonant pressure sensor mentioned in the example of the present application can output a corresponding electrical signal based on the received pressure to be detected.

[0073] In order to enable those skilled in the art to better understand the present application, the piezoelectric resonant pressure sensor, compensation system and preparation method provided by the example of the present application will be clearly and completely described below in conjunction with the accompanying drawings.

[0074] Exemplarily, the present application provides a piezoelectric resonant pressure sensor. Figure 1 A schematic diagram of the structure of a piezoelectric resonant pressure sensor provided as an example in this application. Figure 2 A top view of a piezoelectric resonant pressure sensor provided as an example of the present application. Figure 3 for Figure 2 Sectional view of AA. Figure 4 for Figure 2 Cross-sectional view along BB. Figure 5 for Figure 2 Cross-sectional view along CC. Figure 6 For this application example Figure 2 Diagram of the electrode arrangement of the structure shown. Figure 7 for Figure 6 Cross-sectional view along DD.

[0075] Please refer to Figure 1 to Figure 7 , the piezoelectric resonant pressure sensor 100 may include a piezoelectric component 110, a resonant component 120 and a pressure sensitive component 130. The piezoelectric component 110 is electrically connected to an external circuit. The resonant component 120 is connected to one side of the piezoelectric component 110, and a resonant cavity 121 is provided on the side of the resonant component 120 away from the piezoelectric component 110. The pressure sensitive component 130 is provided on the side of the resonant component 120 away from the piezoelectric component 110, and a pressure cavity 131 is provided on the side of the pressure sensitive component 130 away from the resonant component 120, and the pressure cavity 131 is used to receive the pressure to be detected. Among them, the piezoelectric resonant pressure sensor 100 is provided with a first groove 140, and the first groove 140 is provided in the resonant component 120, and along the direction from the piezoelectric component 110 to the resonant component 120, at least part of the projection of the first groove 140 falls within the projection range of the resonant cavity 121.

[0076] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, during the use of the piezoelectric resonant pressure sensor 100, the pressure chamber 131 can receive the pressure to be detected. Since the pressure sensitive component 130 is arranged at the end of the resonant component 120 away from the piezoelectric component 110, and the pressure chamber 131 is a part of the pressure sensitive component 130. Therefore, the pressure to be detected acting on the pressure sensitive component 130 can be transmitted to the piezoelectric component 110 through the resonant component 120, and the piezoelectric component 110 can output a corresponding electrical signal based on the received pressure to be detected. Since the piezoelectric component 110 is electrically connected to the external circuit, the electrical signal can be transmitted to the external circuit and converted into other signals, so that the operator can know the relevant parameters of the pressure to be detected.

[0077] The relevant parameters of the pressure to be detected include but are not limited to the numerical value of the pressure to be detected and the direction of the pressure to be detected.

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

[0079] The pressure sensitive component 130 may include only the pressure sensitive film 132, or may include the pressure sensitive film 132 and other structures connected to the pressure sensitive film 132. The pressure sensitive film 132 refers to the film in the pressure sensitive component 130 that mainly receives the pressure to be detected.

[0080] In the case where the pressure sensitive component 130 includes only the pressure sensitive film 132, the pressure cavity 131 may be a space where the pressure sensitive film 132 is away from the resonance component 120. In the case where the pressure sensitive component 130 includes the pressure sensitive film 132 and other structures connected to the pressure sensitive film 132, the pressure cavity 131 may also be a space formed by the pressure sensitive film 132 and other structures connected to the pressure sensitive film 132, which is not specifically limited in this example of the present application.

[0081] 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.

[0082] 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.

[0083] The resonant component 120 may be an integrated structure, or may be formed by a plurality of parts. The resonant component 120 may include a resonant film 122, which may be disposed on a side of the resonant component 120 close to the piezoelectric component 110, and the resonant film 122 may cooperate with other structures of the resonant component 120 to form a resonant cavity 121.

[0084] The pressure sensitive component 130 and the resonance component 120 may be integrally formed, or the pressure sensitive component 130 and the resonance component 120 may be formed by the cooperation of multiple parts. The example of the present application does not limit the specific implementation of the pressure sensitive component 130 and the resonance component 120.

[0085] 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.

[0086] Along the direction from the resonance component 120 toward the pressure sensitive component 130, the projection of the resonance cavity 121 may also fall within the projection range of the pressure cavity 131, the projection of part of the resonance cavity 121 may also fall within the projection range of the pressure cavity 131, and the projection of the resonance cavity 121 may also be separated from the projection of the pressure cavity 131. The example of this application does not specifically limit the positional relationship between the resonance cavity 121 and the pressure cavity 131.

[0087] 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, lead zirconate titanate, ZnO, and LiNbO3. Due to the piezoelectricity of the piezoelectric thin film material, when the piezoelectric layer 114 receives the pressure to be detected, the two opposite sides of the piezoelectric layer 114 can generate charges to form a potential difference, that is, the positive piezoelectric effect; similarly, the piezoelectric layer 114 will deform when driven by a voltage, that is, the inverse piezoelectric effect. The positive piezoelectric effect and the inverse piezoelectric effect of the piezoelectric layer 114 are used to obtain the relevant parameters of the pressure to be detected.

[0088] 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.

[0089] 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.

[0090] The electrodes may include a first electrode 113, a first lead electrode 111, a second electrode 115, and a second lead electrode 112. The second electrode 115 may be disposed on a side of the piezoelectric layer 114 facing the resonance component 120. The first electrode 113 may be disposed on a side of the piezoelectric layer 114 facing away from the resonance component 120.

[0091] The first lead electrode 111 can realize electrical connection between the first electrode 113 and an external circuit, and the second lead electrode 112 can realize electrical connection between the second electrode 115 and an external circuit.

[0092] At least two first electrodes 113 may be provided, one of which is a driving electrode and the other is an excitation electrode. The driving electrode is used to drive the piezoelectric layer 114 to vibrate, and the detection electrode is used to detect the vibration of the piezoelectric layer 114.

[0093] The multiple first electrodes arranged at intervals may be distributed in a straight line or in a tuning fork shape. The multiple first electrodes may also be combined to form other structures. The example of the present application does not limit the specific arrangement of the first electrodes.

[0094] In the example of the present application, the resonance principle of the piezoelectric resonant pressure sensor 100 is the same as the resonance principle of the piezoelectric resonant pressure sensor 100 in the prior art, and the example of the present application will not be further described here.

[0095] The first groove 140 may be provided in the piezoelectric component 110 and the resonant component 120, or only in the resonant component 120. There may be one first groove 140, or multiple first grooves 140. The first groove 140 may be connected to the resonant cavity 121, or not connected to the resonant cavity 121.

[0096] Along the direction from the piezoelectric component 110 to the resonant component 120 , the projection of the first groove 140 may be at least one of regular shapes such as a rectangle, a fan, or a wave. The projection of the first groove 140 may also be an irregular shape.

[0097] Along the direction from the piezoelectric component 110 to the resonance component 120, the depth of the first groove 140 can be equal to the thickness of the resonance component 120, the depth of the first groove 140 can be less than the thickness of the resonance component 120, or the depth of the first groove 140 can be greater than the thickness of the resonance component 120. The example of this application does not limit the specific implementation method of the first groove 140.

[0098] Based on the above, according to the piezoelectric resonant pressure sensor 100 provided in the example of the present application, the pressure chamber 131 can receive the pressure to be detected, and the pressure to be detected can be transmitted to the piezoelectric component 110 and the resonant component 120 through the pressure sensitive component 130, and the pressure to be detected is detected through the characteristics of the piezoelectric component 110. Since the piezoelectric component 110 is arranged on the side of the resonant component 120 away from the pressure sensitive component 130, the piezoelectric component 110 is separated from the pressure chamber 131 that receives the pressure to be detected. And since the resonant component 120 is provided with a resonant cavity 121. In the case where the piezoelectric component 110 drives the resonant component 120 to vibrate, the resonant cavity 121 can provide a deformation space for the piezoelectric component 110, thereby reducing the possibility that the piezoelectric component 110 is damaged due to a large deformation amount caused by vibration.

[0099] 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.

[0100] In addition, when the pressure to be detected is transmitted to the piezoelectric component 110 through the resonant component 120, the structure of the resonant component 120 connected between the piezoelectric component 110 and the pressure sensitive component 130 may be deformed under the action of the pressure to be detected. By providing the first groove 140, a deformation space can be provided for the structure of the resonant component 120 to be deformed.

[0101] Compared with the prior art in which the resonant component 120 is a block structure, in the example of the present application, the first groove 140 is provided in the resonant component 120. Therefore, the first groove 140 can divide the resonant component 120 into a plurality of spaced structures. The resonant component 120 is more likely to deform under the action of the pressure to be detected, thereby improving the detection sensitivity of the piezoelectric resonant pressure sensor 100, and further improving the detection accuracy of the piezoelectric resonant pressure sensor 100.

[0102] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, please refer to Figure 1 There may be a plurality of first grooves 140 , and the plurality of first grooves 140 are arranged at intervals, and a deformation structure 150 is formed between two adjacent first grooves 140 .

[0103] The first grooves 140 may be provided with two, three, four, five or even more. The plurality of first grooves 140 may be arranged randomly, or may be arranged at an angle. In this case, the plurality of first grooves 140 may be connected, or may not be connected. The plurality of first grooves 140 may also be arranged substantially in parallel, and the specific implementation of the first grooves 140 is not limited in the example of the present application.

[0104] The plurality of first grooves 140 are arranged substantially in parallel, which means that the angle between two adjacent first grooves 140 is greater than or equal to zero degree and less than 10 degrees.

[0105] A deformation structure 150 may be formed between two adjacent first grooves 140 .

[0106] The deformable structure 150 may be cylindrical, prism-shaped, truncated cone-shaped or other regular shapes, or may be irregularly shaped. There may be one deformable structure 150, or there may be two, three, or even more deformable structures 150. The specific implementation of the deformable structure 150 is not limited in the example of the present application.

[0107] One end of the deformable structure 150 may be connected to the pressure sensitive film 132, and the other end of the deformable structure 150 may be connected to the piezoelectric layer 114. Alternatively, one end of the deformable structure 150 may be connected to the pressure sensitive film 132, and the other end of the deformable structure 150 is a free end. The example of this application does not specifically limit the specific connection method between the deformable structure 150 and other structures.

[0108] In the process of transmitting the pressure to be detected to the piezoelectric component 110 through the resonant component 120, the deformable structure 150 may be deformed based on the effect of the pressure to be detected. Since the deformable structure 150 is a structure disposed between the two first grooves 140, the first grooves 140 on both sides of the deformable structure 150 can provide deformation space for the deformation of the deformable structure 150, thereby reducing the possibility that the deformable structure 150 contacts other structures of the piezoelectric resonant pressure sensor 100 during the deformation process, resulting in damage to the deformable structure 150.

[0109] In the example of the present application, since there are multiple first grooves 140 and a deformation structure 150 is formed between two adjacent first grooves 140, the contact area between the deformation structure 150 and the pressure sensitive component 130 is smaller, and the deformation structure 150 is more likely to deform, which can further improve the detection sensitivity and detection accuracy of the piezoelectric resonant pressure sensor 100.

[0110] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, please refer to Figure 1 , the plurality of first trenches 140 may be evenly arranged.

[0111] In the case where the plurality of first grooves 140 are cross-arranged, center lines of the plurality of first grooves 140 may intersect at one point, and the uniform arrangement of the plurality of first grooves 140 may mean that the angles between two adjacent first grooves 140 are equal.

[0112] When the plurality of first grooves 140 are substantially parallel, the uniform arrangement of the plurality of first grooves 140 may mean that the distance between two adjacent first grooves 140 is equal. Of course, the plurality of first grooves 140 may also be uniformly arranged in other ways, and the present application example does not specifically limit the arrangement of the first grooves 140.

[0113] In the example of the present application, by arranging a plurality of first grooves 140 in an even arrangement, the deformation amplitudes of different deformation structures 150 under the action of the same pressure to be detected can be relatively the same, thereby making the deformation amounts transmitted to the piezoelectric component 110 by different deformation structures 150 relatively the same, thereby ensuring the detection accuracy of the detection pressure by the piezoelectric resonant pressure sensor 100.

[0114] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, please refer to Figure 2 The first groove 140 may include a first sub-groove 141 and a second sub-groove 142 that are connected to each other, and the second sub-groove 142 is connected to the resonant cavity 121 .

[0115] Along the direction from the piezoelectric component 110 to the resonant component 120 , the projection shape of the first sub-slot 141 and the projection shape of the second sub-slot 142 may be the same or different.

[0116] The center line of the first sub-slot 141 and the center line of the second sub-slot 142 can be set at an angle, or the center line of the first sub-slot 141 and the center line of the second sub-slot 142 can be located on the same straight line. The example of this application does not limit the specific settings of the first sub-slot 141 and the second sub-slot 142.

[0117] Taking the first sub-groove 141 as an example, the projection shape of the first sub-groove 141 may be a regular shape such as a rectangle or a sector, or the projection shape of the first sub-groove 141 may be an irregular shape.

[0118] At the position where the first sub-groove 141 is connected to the second sub-groove 142, the distance between the two side walls of the first sub-groove 141 may be equal to the distance between the two side walls of the second sub-groove 142, the distance between the two side walls of the first sub-groove 141 may be smaller than the distance between the two side walls of the second sub-groove 142, and the distance between the two side walls of the first sub-groove 141 may be larger than the distance between the two side walls of the second sub-groove 142. Along the direction from the first sub-groove 141 to the second sub-groove 142, the distance between the two side walls of the first groove 140 may gradually change. The example of the present application does not limit the specific implementation of the first sub-groove 141 and the second sub-groove 142.

[0119] Based on the above, the first groove 140 includes a first sub-groove 141 and a second sub-groove 142 which are connected to each other. By setting the relative position relationship between the first sub-groove 141 and the second sub-groove 142, the cross-sectional area of ​​the deformable structure 150 can be made smaller, so that the deformation amplitude of the deformable structure 150 under the same pressure to be detected is larger, which is convenient for improving the detection sensitivity of the piezoelectric resonant pressure sensor 100. Based on this, under the action of different pressures to be detected, the deformation amplitude of the deformable structure 150 will be relatively different, which is convenient for improving the detection accuracy of the piezoelectric resonant pressure sensor 100.

[0120] Since the second sub-slot 142 is connected to the resonant cavity 121 along the direction of the piezoelectric component 110 toward the resonant component 120, compared with the case where the second sub-slot 142 and the resonant cavity 121 are spaced apart, the deformation structure 150 is more likely to deform, which can further improve the detection sensitivity of the piezoelectric resonant pressure sensor 100, thereby improving the detection accuracy of the piezoelectric resonant pressure sensor 100.

[0121] In the piezoelectric resonant pressure sensor 100 provided in the above example, only the first groove 140 may be provided to include the first sub-groove 141 and the second sub-groove 142, or only the first groove 140 may be provided to be connected to the resonant cavity 121, or the first groove 140 may be provided to include the first sub-groove 141 and the second sub-groove 142 that are connected to each other, and the second sub-groove 142 may be provided to be connected to the resonant cavity 121. The example of the present application does not limit the specific setting method of the first groove 140.

[0122] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, at the position where the first sub-slot 141 is connected to the second sub-slot 142, the distance between the two groove side walls of the first sub-slot 141 is a first distance, and the distance between the two groove side walls of the second sub-slot 142 is a second distance, and the second distance is greater than the first distance.

[0123] Along the direction from the first sub-groove 141 to the second sub-groove 142, the distance between the two groove side walls of the first sub-groove 141 can remain unchanged, and the distance between the two groove side walls of the first sub-groove 141 can also change. On this basis, the distance between the two side walls of the second sub-groove 142 can remain unchanged, and the distance between the two side walls of the second sub-groove 142 can also change. This example of the application does not impose specific restrictions on this, as long as it is ensured that at the position where the first sub-groove 141 and the second sub-groove 142 are connected, the distance between the two groove side walls of the second sub-groove 142 is greater than the distance between the two groove side walls of the first sub-groove 141.

[0124] Based on the above, by setting the second distance to be greater than the first distance, that is, at the connection point between the first sub-groove 141 and the second sub-groove 142, the distance between the two groove side walls of the second sub-groove 142 is greater than the distance between the two groove side walls of the first sub-groove 141, the cross-sectional area of ​​the deformation structure 150 between two adjacent second sub-grooves 142 can be made smaller, so that the deformation structure 150 is easier to deform under the action of the pressure to be detected, thereby improving the detection sensitivity of the piezoelectric resonant pressure sensor 100, and further improving the detection accuracy of the piezoelectric resonant pressure sensor 100.

[0125] There are many ways to dispose the first groove 140 . Next, the way to dispose the first groove 140 is described.

[0126] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, along the direction from the piezoelectric component 110 to the resonant component 120, the projection of part of the first groove 140 falls within the projection range of the resonant cavity 121. The first groove 140 is provided between the piezoelectric component 110 and the pressure sensitive component 130. Alternatively, the first groove 140 is provided on a side of the resonant component 120 away from the pressure sensitive component 130, and the notch of the first groove 140 is provided away from the pressure sensitive component 130.

[0127] Along the direction from the piezoelectric component 110 to the resonance component 120, the projection of part of the first groove 140 falls within the projection range of the resonance cavity 121. At least part of the first groove 140 can be provided in the resonance film 122, but does not penetrate the resonance film 122. In this case, the first groove 140 can be spaced apart from the resonance cavity 121. Alternatively, at least part of the first groove 140 can be provided in the resonance film 122, and penetrate the resonance film 122 along the direction from the piezoelectric component 110 to the resonance component 120. In this case, the first groove 140 can be connected to the resonance cavity 121.

[0128] Exemplarily, the resonant component 120 may include a resonant substrate 123, and the resonant substrate 123 is disposed on a side of the pressure sensitive component 130 away from the pressure chamber 131. Along the direction of the resonant component 120 toward the pressure sensitive component 130, the first groove 140 may be disposed between the resonant film 122 and the pressure sensitive film 132. Along the direction of the cross section of the resonant cavity 121, the first groove 140 is disposed between the resonant substrate 123 and the deformation structure 150.

[0129] The first groove 140 can keep a distance between the resonant substrate 123 and the deformable structure 150, thereby reducing the cross-sectional area of ​​the deformable structure 150. During the transmission of the pressure to be detected, the deformation amplitude of the deformable structure 150 is larger, thereby improving the detection sensitivity and detection accuracy of the piezoelectric resonant pressure sensor 100.

[0130] Exemplarily, the resonant component 120 may further include a resonant substrate 123 , and the configuration of the resonant substrate 123 is similar to the configuration of the resonant substrate 123 mentioned in the aforementioned example, and the example of the present application will not be described in detail here.

[0131] The first groove 140 may also be disposed on a side of the resonance component 120 away from the pressure sensitive component 130 , and a notch of the first groove 140 is opened away from the pressure sensitive component 130 .

[0132] The first groove 140 mentioned in the example of the present application can maintain a distance between the resonant substrate 123 and the deformable structure 150, thereby reducing the cross-sectional area of ​​the deformable structure 150. During the transmission of the pressure to be detected, the deformation amplitude of the deformable structure 150 is larger, so as to improve the detection sensitivity and detection accuracy of the piezoelectric resonant pressure sensor 100.

[0133] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, please refer to Figure 1 to Figure 5 The center lines of the plurality of first grooves 140 intersect at the intersection. The piezoelectric resonant pressure sensor 100 is provided with at least one second groove 170 , which is provided at one end of the first groove 140 away from the intersection, and is connected to the first groove 140 .

[0134] The center lines of multiple first grooves 140 can intersect at an intersection. For example, the opening of the first groove 140 is set toward the side of the piezoelectric component 110 away from the resonance component 120. The intersection can be located on the center line of the piezoelectric component 110, and there can be no distance between the intersection and the center line of the piezoelectric component 110. The example of this application does not limit the specific setting of the intersection.

[0135] The number of the second grooves 170 may be one, two, three or even more. In the case where the number of the first grooves 140 is multiple, the second grooves 170 may be arranged around one end of the first grooves 140 away from the intersection.

[0136] Along the direction from the piezoelectric component 110 to the resonance component 120 , the shape of the projection of the second groove 170 may be similar to or different from the shape of the projection of the piezoelectric component 110 , and this example of the application does not impose any specific limitation on this.

[0137] Based on the above, by setting the center lines of multiple first grooves 140 to intersect at the intersection, and setting the second groove 170 on the side of the first groove 140 away from the intersection, the second groove 170 is connected to the first groove 140. Based on this, the cross-sectional area of ​​the deformation structure 150 between any two first grooves 140 can be further reduced, so that the deformation structure 150 is more easily deformed under the action of the pressure to be detected, thereby improving the detection sensitivity and detection accuracy of the piezoelectric resonant pressure sensor 100.

[0138] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, along the direction from the piezoelectric component 110 to the resonant component 120, the projection of the second groove 170 is spaced from the projection of the resonant cavity 121. A deformation structure 150 is formed between the second groove 170, the first groove 140 and the resonant cavity 121, and a resonant film 122 is provided on the side of the deformation structure 150 facing the piezoelectric component 110, and the resonant film 122 cooperates with the deformation structure 150 to form the resonant cavity 121.

[0139] The configuration of the second groove 170 is similar to that of the first groove 140 . For the configuration of the second groove 170 , reference may be made to the above related description, and this application example will not be further described here.

[0140] The deformable structure 150 may be an integrated structure with the resonant film 122. In this case, the resonant cavity 121 may be a cavity formed by removing the middle portion of a block-shaped structure. The resonant film 122 may be a partial block-shaped structure corresponding to the cavity bottom of the resonant cavity 121. The deformable structure 150 may be a partial block-shaped structure corresponding to the side wall of the resonant cavity 121.

[0141] The deformable structure 150 can also be connected to the resonant film 122 by bonding or other means. In this case, the deformable structure 150 can include multiple ones, and different deformable structures 150 can be connected to the side walls of the corresponding resonant film 122. In this case, the resonant film 122 can serve as the bottom wall of the resonant cavity 121, and the deformable structure 150 can serve as the side wall of the resonant cavity 121. The resonant film 122 and the deformable structure 150 together enclose the resonant cavity 121.

[0142] Since the pressure sensitive film 132 is disposed on one side of the deformation structure 150, and the piezoelectric component 110 is disposed on the other side of the deformation structure 150, the pressure to be detected acting on the pressure sensitive film 132 can be transmitted to the resonant film 122 and the piezoelectric component 110 through the deformation structure 150, and stress is generated in the resonant film 122 and the piezoelectric component 110, thereby causing a change in the vibration frequency of the resonant film 122 and 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 caused by vibration.

[0143] The deformation structure 150 can directly or indirectly connect the resonant film 122 to one side of the pressure sensitive film 132. Figure 8 A schematic diagram of the working principle of a piezoelectric resonant pressure sensor provided for this application example, please refer to Figure 8 , the deformation structure 150 can change the direction of action of the pressure to be detected.

[0144] Exemplarily, the pressure to be detected acts on the pressure sensitive film 132 in a direction perpendicular to the pressure sensitive film 132. The pressure to be detected acting on the pressure sensitive film 132 can be transmitted to the resonant film 122 through the deformation structure 150. The deformation structure 150 can convert the pressure to be detected perpendicular to the pressure sensitive film 132 into a working stress having an angle between the direction of action and the direction of action of the pressure to be detected.

[0145] In summary, the deformation structure 150 can connect the pressure sensitive film 132 and the piezoelectric component 110, and the deformation structure 150 can change the direction of the pressure to be detected, so that the pressure to be detected acting vertically on the piezoelectric component 110 is smaller, which further reduces the possibility of damage to the piezoelectric component 110, improves the pressure-bearing capacity of the resonant film 122, expands the detection range of the piezoelectric resonant pressure sensor 100, and ensures the linearity of the piezoelectric resonant pressure sensor 100 within the pressure detection range.

[0146] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the side of the deformable structure 150 close to the pressure sensitive component 130 can be an anchor point, the distance between the anchor point and the resonant film 122 is the third distance, the distance between the anchor point and the pressure sensitive component 130 is the fourth distance, and the third distance is greater than the fourth distance. The anchor point is the main force point of the deformable structure 150.

[0147] By setting the third distance to be greater than the fourth distance, the resonant film 122, the pressure sensitive component 130 and the anchor point can work together to form a lever, the third distance is the first lever arm, and the fourth distance is the second lever arm. Based on the lever principle, the deformation structure 150 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.

[0148] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the piezoelectric resonant pressure sensor 100 is provided with at least one second groove 170. The second groove 170 can be provided between the resonant film 122 and the pressure sensitive film 132. Alternatively, the second groove 170 can also be provided on the side of the resonant component 120 away from the pressure sensitive component 130, and the notch of the second groove 170 is opened away from the pressure sensitive component 130.

[0149] The configuration of the second groove 170 is similar to that of the first groove 170 . Regarding the configuration of the second groove 170 , please refer to the above description of the first groove 140 . This application example will not be described in detail here.

[0150] In the case where only one second groove 170 is provided, the piezoelectric resonant pressure sensor 100 may be provided with a lead bridge 171 or may not be provided with the lead bridge 171 .

[0151] In the case of at least two second grooves 170, a lead bridge 171 may be formed between two adjacent second grooves 170, and the number of lead bridges 171 may be one, two, three, four or more. Figure 1 and Fig. 9 like Figure 1 There are two lead bridges in the Fig. 9 A schematic diagram of the structure of a piezoelectric resonant pressure sensor provided as an example of this application, Fig. 9 The plurality of lead bridges 171 can be arranged in a cross shape, a M shape, a straight shape or other irregular shapes.

[0152] The number of the lead bridges 171 may be equal to and correspond to the number of the first lead electrodes 111 , or the number of the lead bridges 171 may be less than the number of the first lead bridges 171 , which is not limited in this example of the present application.

[0153] The lead bridge 171 can provide a location for the lead connecting the first lead electrode 111 and the first electrode 113 , and adjust the location of the first lead electrode 111 to ensure the connection reliability between the first lead electrode 111 and the first electrode 113 .

[0154] 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.

[0155] An angle may be formed between the beam structure 172 and the lead bridge 171 .

[0156] 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.

[0157] 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.

[0158] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the pressure sensitive component 130 may further include a buried oxide layer 320 , and the sidewalls of the buried oxide layer 320 cooperate with the sidewalls of the resonant substrate 133 in the pressure sensitive component 130 to form the sidewalls of the pressure cavity 131 .

[0159] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, Fig.10 For a schematic diagram of the structure of a piezoelectric resonant pressure sensor provided in this application example, please refer to Fig.10 The piezoelectric resonant pressure sensor 100 may further include a cover 160 . The cover 160 is disposed on a side of the piezoelectric component 110 away from the pressure sensitive component 130 . The cover 160 is directly or indirectly connected to the piezoelectric component 110 .

[0160] The cover 160 may be made of a silicon wafer, a glass wafer 400 , an inorganic semiconductor material, or other amorphous inorganic non-metallic materials.

[0161] 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 component 120 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.

[0162] In the present example, the cover 160 may be bonded to a side of the piezoelectric component 110 that faces away from the resonance component 120 , and the cover 160 may close the notch of the first groove 140 and the notch of the second groove 170 .

[0163] The bonding method may be anodic bonding, or metal bonding such as Al-Ge, Au-Au, or other bonding methods.

[0164] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, please refer to Fig.10 The cover 160 may be provided with an adsorption structure 161 on one side facing the piezoelectric component 110. The adsorption structure 161 may be a thin film getter or other structure capable of maintaining a vacuum inside the piezoelectric resonant pressure sensor 100.

[0165] The adsorption structure 161 can adsorb the gas or other substances inside the piezoelectric resonant pressure sensor 100 so that the inside of the piezoelectric resonant pressure sensor 100 is maintained in a vacuum state, thereby ensuring the measurement accuracy and sensitivity of the piezoelectric resonant pressure sensor 100 and extending the service life of the piezoelectric resonant pressure sensor 100.

[0166] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the piezoelectric resonant pressure sensor 100 may be an absolute pressure sensor, or the piezoelectric resonant pressure sensor 100 may be a relative pressure sensor.

[0167] Exemplarily, the piezoelectric resonant pressure sensor 100 may be an absolute pressure sensor. In this case, the cover 190 may be bonded to the side of the piezoelectric component 110 facing away from the resonant film 120 under a vacuum environment. The absolute pressure sensor is used to measure absolute pressure and can convert the absolute pressure of a gas or liquid into an equivalent electrical signal output.

[0168] Exemplarily, the piezoelectric resonant pressure sensor 100 may be a relative pressure sensor. In this case, the cover 190 may be bonded to the side of the piezoelectric component 110 that is away from the resonant film 120 under a certain pressure environment. The relative pressure sensor is measured based on atmospheric pressure, so the measurement result of the relative pressure sensor is relative to the atmospheric pressure. Therefore, the relative pressure sensor can be used to measure the difference in relative pressure.

[0169] 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.

[0170] Based on the piezoelectric resonant pressure sensor 100 provided in the above example, please refer to Figure 3A protective layer 180 may be provided on the side of the piezoelectric component 110 facing away from the resonance component 120 . The protective layer 180 may be made of silicon dioxide material or other moisture-proof material.

[0171] The protective layer 180 can isolate the piezoelectric component 110 from the atmospheric environment, and the protective layer 180 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, thereby ensuring the working reliability of the piezoelectric resonant pressure sensor 100. The protective layer 180 can also play a role in temperature compensation during the operation of the piezoelectric resonant pressure sensor 100.

[0172] During the use of the piezoelectric resonant pressure sensor 100, only the cover 160 may be provided, only the protective layer 180 may be provided, both the cover 160 and the protective layer 180 may be provided, or neither the cover 160 nor the protective layer 180 may be provided. This application example does not impose any specific limitation on this.

[0173] Exemplarily, the example of the present application provides a method for preparing a piezoelectric resonant pressure sensor 100, which is applicable to the piezoelectric resonant pressure sensor 100 provided in any of the above examples, and the following processing method can be completed by MEMS processing equipment. In the example of the present application, the piezoelectric resonant pressure sensor 100 can be processed from multiple SOI wafers, or from a CSOI (buried cavity SOI) wafer and an SOI wafer, or from a CSOI wafer. The example of the present application only takes the example of a piezoelectric resonant pressure sensor 100 processed from a CSOI wafer as an example for explanation.

[0174] The CSOI wafer includes a device layer 310 , a buried oxide layer 320 and a substrate layer 330 . The substrate layer 330 is provided with a resonant cavity 121 , and the device layer 310 closes the opening of the resonant cavity 121 . Fig.11 For a schematic diagram of a piezoelectric resonant pressure sensor preparation method provided in this application example, please refer to Fig.11 , the method specifically comprises the following steps:

[0175] S110, take a CSOI wafer, and process the piezoelectric component 110 on the side of the device layer 310 away from the buried oxide layer 320. For details, please refer to Figure 12 to Figure 14 , Fig.12 A schematic diagram of the structure of an unprocessed CSOI wafer provided as an example of this application, Fig.13 A schematic diagram of a structure in which a piezoelectric component is deposited on the side of the device layer away from the buried oxide layer provided in the example of this application, Fig.14 A method based on Fig.13 Schematic diagram of the structure of the piezoelectric component after processing.

[0176] The piezoelectric component 110 may be disposed on a side of the device layer 310 facing away from the buried oxide layer 320 by deposition, sputtering or other methods.

[0177] In some possible implementations, the piezoelectric component 110 includes a lead electrode, a first electrode 113, a piezoelectric layer 114, and a second electrode 115. S110 specifically includes the following steps:

[0178] S111, sequentially depositing the second electrode layer, the piezoelectric layer 114 and the first electrode layer, for details, please refer to Fig.13 .

[0179] S112, patterning the first electrode layer to form at least two first electrodes 113, see Fig.14 .

[0180] In some possible implementations, after S112, the following steps may be further included:

[0181] S1121, depositing a protective layer 180, for details, please refer to Fig.15 , Fig.15 A method based on Fig.14 Schematic diagram of the structure in which a protective layer 180 is disposed on a side of the piezoelectric component away from the device layer.

[0182] Because the first electrode 113 has been patterned before the protective layer 180 is deposited, which causes a portion of the piezoelectric layer 114 to be exposed, a portion of the protective layer 180 may contact the first electrode 113 , and another portion of the protective layer 180 may contact the piezoelectric layer 114 .

[0183] S113, a second connection hole 1121 is processed at a position connected to the second electrode 115, and a connector is inserted through the second connection hole 1121 to be connected to the second electrode 115. For details, please refer to Fig.16 , Fig.16 A method based on Fig.15 Schematic diagram of the structure of processing the second connecting hole from the protective layer.

[0184] The second connection hole 1121 can be processed to the side of the second electrode 115 away from the resonance component 120, and part of the hole wall of the second connection hole 1121 can also be arranged on the second electrode 115. As long as the conductive structure passing through the second connection hole 1121 can be connected to the second electrode 115, the example of this application does not make any specific restrictions on this.

[0185] S114, processing a first connection hole 1111 at a position connected to the first electrode 113, and the conductive structure is arranged through the first connection hole 1111 to be connected to the first electrode 113. For details, please refer to Fig.17 , Fig.17A method based on Fig.16 or Fig.15 Schematic diagram of the structure of processing the first connecting hole from the protective layer. Fig.17 and Fig.16 The cross-sectional directions are different.

[0186] The first connection hole 1111 can be processed to the side of the first electrode 113 away from the resonance component 120, and part of the hole wall of the first connection hole 1111 can also be arranged on the first electrode 113. As long as the conductive structure passing through the first connection hole 1111 can be connected to the first electrode 113, the example of this application does not make any specific restrictions on this.

[0187] During the manufacturing process of the piezoelectric resonant pressure sensor 100 , the first connection hole 1111 may be processed first and then the second connection hole 1121 , that is, S114 is performed first and then S113 , and this example of the present application does not impose any specific limitation on this.

[0188] S115, depositing the lead electrode layer 340, a portion of the lead electrode layer 340 may be located in the second connection hole 1121 and connected to the second electrode 115, for details, please refer to Fig.18 , Fig.18 A method based on Fig.17 Schematic diagram of the structure of depositing a lead electrode layer on the side of the protection layer 180 away from the device layer.

[0189] S116, patterning the lead electrode layer 340 to form at least one first lead electrode 111 and at least one second lead electrode 112, see Fig.19 , Fig.19 A method based on Fig.18 Schematic diagram of the structure for processing the lead electrode layer.

[0190] The side of the first lead electrode 111 close to the first electrode 113 is connected to the first electrode 113, and the side of the first lead electrode 111 away from the first electrode 113 can be connected to the first part of the external circuit. The side of the second lead electrode 112 close to the second electrode 115 is connected to the second electrode 115, and the side of the second lead electrode 112 away from the second electrode 115 can be connected to the second part of the external circuit. The second lead electrode 112 is the conductive structure mentioned in the above example. Based on this, the connection between the piezoelectric resonant pressure sensor 100 and the external circuit can be realized.

[0191] S120, processing the pressure cavity 131 on the side of the substrate layer 330 away from the buried oxide layer 320, please refer to Fig. 20 , Fig. 20 A method based on Fig.19 Schematic diagram of the structure of processing the pressure cavity on the side of the substrate layer away from the device layer.

[0192] The pressure chamber 131 can be formed by etching or other processing methods on the side of the substrate layer 330 away from the buried oxide layer 320. Etching can include dry etching and wet etching, wherein dry etching includes but is not limited to xenon difluoride and plasma etching, and wet etching includes but is not limited to HF etching and electrochemical etching.

[0193] S130 , processing a first groove 140 on a side of the piezoelectric component 110 away from the device layer 310 , and along a direction from the piezoelectric component 110 toward the resonance component 120 , at least a portion of the projection of the first groove 140 falls within a projection range of the resonance cavity 121 .

[0194] In the example of the present application, the processing of the first groove 140 can be performed before depositing the piezoelectric component 110, and the processing of the first groove 140 can also be performed after depositing the piezoelectric component 110, and the example of the present application does not make specific limitations on this.

[0195] For example, based on the preparation method provided in the above example, in S130, when processing the first groove 140 on the side of the piezoelectric component 110 away from the device layer 310, the preparation method may further include:

[0196] S131, processing a second groove 170 on the side of the piezoelectric component 110 away from the device layer 310, please refer to Fig.21 , Fig.21 A method based on Fig. 20 Schematic diagram of the structure of processing the second groove from the protective layer.

[0197] When the center lines of the plurality of first grooves 140 intersect at an intersection, the second groove 170 may be disposed at an end of the first groove 140 away from the intersection, and the second groove 170 is communicated with the first groove 140 .

[0198] Based on the processing method of the piezoelectric resonant pressure sensor 100, the first groove 140 and the second groove 170 can be processed at the same time. The first groove 140 and the second groove 170 can also be processed before processing the pressure chamber 131, or after processing the pressure chamber 131, which is not limited in this application example.

[0199] Based on the above, according to the piezoelectric resonant pressure sensor 100 provided in the example of the present application, the pressure chamber 131 can receive the pressure to be detected, and the pressure to be detected can be transmitted to the piezoelectric component 110 and the resonant component 120 through the pressure sensitive component 130, and the pressure to be detected is detected through the characteristics of the piezoelectric component 110. Since the piezoelectric component 110 is arranged on the side of the resonant component 120 away from the pressure sensitive component 130, the piezoelectric component 110 is separated from the pressure chamber 131 that receives the pressure to be detected. And since the resonant component 120 is provided with a resonant cavity 121. In the case where the piezoelectric component 110 drives the resonant component 120 to vibrate, the resonant cavity 121 can provide a deformation space for the piezoelectric component 110, thereby reducing the possibility that the piezoelectric component 110 is damaged due to a large deformation amount caused by vibration.

[0200] 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.

[0201] In addition, when the pressure to be detected is transmitted to the piezoelectric component 110 through the resonant component 120, the structure of the resonant component 120 connected between the piezoelectric component 110 and the pressure sensitive component 130 may be deformed under the action of the pressure to be detected. By providing the first groove 140, a deformation space can be provided for the structure of the resonant component 120 to be deformed.

[0202] Compared with the prior art in which the resonant component 120 is a block structure, in the example of the present application, the first groove 140 is provided in the resonant component 120. Therefore, the first groove 140 can divide the resonant component 120 into a plurality of spaced structures. The resonant component 120 is more likely to deform under the action of the pressure to be detected, thereby improving the detection sensitivity of the piezoelectric resonant pressure sensor 100, and further improving the detection accuracy of the piezoelectric resonant pressure sensor 100.

[0203] In some possible implementations, the piezoelectric resonant pressure sensor 100 may further include a cover 160, and the cover 160 is bonded to the piezoelectric component 110. The bonding method may be anodic bonding, or metal bonding such as Al-Ge, Au-Au, or other bonding methods. Next, the bonding method of the cover 160 and the piezoelectric component 110 is described by taking the Al-Ge bonding connection between the cover 160 and the piezoelectric component 110 as an example.

[0204] Based on the above-mentioned method for manufacturing the piezoelectric resonant pressure sensor 100, in S116, after patterning the lead electrode layer 340 to form at least one first lead electrode 111 and at least one second lead electrode 112, the method further includes:

[0205] S1161, in the patterned electrode layer, in addition to forming at least one first lead electrode 111 and at least one second lead electrode 112, a first connecting member 162 is also formed. Fig.19 .

[0206] The first connecting member 162 may be roughly in the shape of a circular ring, a square ring or other structures. The first connecting member 162 may be a sealed ring structure. The first connecting member 162 may also be composed of a plurality of spaced segments. This application example does not impose any specific limitation on this.

[0207] S140, taking a glass wafer 400, and etching a cavity to form a cover 160 may specifically include:

[0208] S141, depositing a Ge layer on one side of the glass wafer 400, see Fig. 22 and Fig.23 . Fig. 22 A schematic diagram of the structure of a glass wafer provided as an example of this application, Fig.23 A schematic diagram of a structure for processing a Ge layer on a glass wafer provided as an example of this application.

[0209] S142, etching the Ge layer to form a second connecting member 163, please refer to Fig.24 , Fig.24 A method based on Fig.23 Structural schematic diagram of processing the second connecting piece.

[0210] The shape of the second connecting member 163 can be the same as or different from the shape of the first connecting member 162. The present application example does not impose any specific restrictions on this. As long as the first connecting member 162 can be connected to the second connecting member 163, the connection between the cover 160 and the piezoelectric component 110 can be achieved.

[0211] S143, a cavity is formed by etching on the side of the glass wafer 400 where the second connector 163 is provided, and the opening of the cavity is arranged toward the side of the glass wafer 400 where the second connector 163 is provided. Fig.25 , Fig.25 A schematic diagram of a structure for forming a cover in a glass wafer processing cavity provided as an example of the present application.

[0212] In some possible implementations, the piezoelectric resonant pressure sensor 100 may further include an adsorption structure 161 .

[0213] Based on the above-mentioned method for manufacturing the piezoelectric resonant pressure sensor 100, in S140, after taking a glass wafer 400 and etching the cavity to form the cover 160, the following steps may also be included:

[0214] S144, an adsorption structure 161 is provided on the cavity wall, please refer to Fig.26 , Fig.26 A schematic diagram of a structure in which an adsorption structure is provided inside a cover provided as an example of the present application.

[0215] Specifically, the connection between the adsorption structure 161 and the cover 160 can be achieved through a vacuum coating process or other processing methods, and this application example does not make any specific limitations on this.

[0216] S150, in a vacuum environment, bonding the cover 160 and the piezoelectric component 110, see Fig. 27 , Fig. 27 A schematic diagram of a structure in which a cover is connected to the side of a protective layer facing away from the piezoelectric layer, provided as an example of the present application.

[0217] The above-mentioned numbers do not limit the order of the steps of the above-mentioned method. During the specific implementation of the preparation method, the implementation steps of the above-mentioned method can be adaptively adjusted based on actual conditions.

[0218] 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.

[0219] Exemplarily, the present application provides a compensation system 200, Fig.28 For a schematic diagram of the compensation system provided for this application example, please refer to Fig.28 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.

[0220] 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.

[0221] When only one compensation sensor 220 is provided, only one detection sensor may be provided, or a plurality of detection sensors may be provided.

[0222] 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.

[0223] 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.

[0224] Since the pressure sensor 210 and the compensation sensor 220 are integrated together, environmental factors such as temperature, vibration, and shock will have the same impact on the resonant component 120 of the pressure sensor 210 and the compensation sensor 220, so that the resonant component 120 of the pressure sensor 210 and the compensation sensor 220 can have the same output based on the influence of environmental factors.

[0225] 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.

[0226] Fig.29 For a schematic diagram of the working process of a compensation system provided for this application example, please refer to Fig.29 , the working process of the compensation sensor 220 is as follows:

[0227] S210 , the driving component 230 is used to drive the pressure sensor 210 and the compensation sensor 220 .

[0228] S220 , 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 .

[0229] S230, 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.

[0230] S240, the calculation module may also calculate the pressure value of the pressure to be detected based on the resonance frequency.

[0231] 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.

[0232] 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.

[0233] 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.

[0234] 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, characterized in that: include: A piezoelectric component is electrically connected to an external circuit; A resonant component connected to one side of the piezoelectric component, wherein a resonant cavity is provided on a side of the resonant component 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 closes the opening of the resonant cavity toward the pressure sensitive component, and a pressure cavity is opened on the side of the pressure sensitive component away from the resonant component, and the pressure cavity is used to receive the pressure to be detected; The piezoelectric resonant pressure sensor is provided with a first groove, which is provided in the resonant component. Along the direction from the piezoelectric component to the resonant component, at least part of the projection of the first groove falls within the projection range of the resonant cavity.

2. The piezoelectric resonant pressure sensor according to claim 1, characterized in that: There are a plurality of the first grooves, and the plurality of the first grooves are arranged at intervals, and a deformation structure is formed between two adjacent first grooves.

3. The piezoelectric resonant pressure sensor according to claim 2, characterized in that: The plurality of first grooves are evenly arranged.

4. The piezoelectric resonant pressure sensor according to any one of claims 1 to 3, characterized in that: The first groove includes a first sub-groove and a second sub-groove that are connected to each other, and the second sub-groove is connected to the resonant cavity.

5. The piezoelectric resonant pressure sensor according to claim 1, characterized in that: Along the direction from the piezoelectric component to the resonant component, the projection of part of the first groove falls within the projection range of the resonant cavity; The first groove is provided between the piezoelectric component and the pressure sensitive component; or, The first groove is arranged on a side of the resonant component away from the pressure sensitive component, and a notch of the first groove is opened away from the pressure sensitive component.

6. The piezoelectric resonant pressure sensor according to claim 2, characterized in that: The center lines of the plurality of first grooves intersect at an intersection; The piezoelectric resonant pressure sensor is provided with at least one second groove, wherein the second groove is provided at an end of the first groove away from the intersection, and the second groove is communicated with the first groove.

7. The piezoelectric resonant pressure sensor according to claim 6, characterized in that: Along the direction from the piezoelectric component to the resonant component, the projection of the second groove is spaced apart from the projection of the resonant cavity; The deformation structure is formed between the second groove, the first groove and the resonant cavity. A resonant film is provided on the side of the deformation structure facing the piezoelectric component. The resonant film cooperates with the deformation structure to form the resonant cavity.

8. The piezoelectric resonant pressure sensor according to any one of claims 1 to 3, 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.

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.

10. A method for preparing a piezoelectric resonant pressure sensor, characterized in that: The piezoelectric resonant pressure sensor according to any one of claims 1 to 8 is used for processing a CSOI wafer into the piezoelectric resonant pressure sensor, wherein the CSOI wafer comprises a device layer, a buried oxide layer and a substrate layer, wherein the substrate layer is provided with a resonant cavity, and the device layer closes the opening of the resonant cavity; The method comprises: Take the CSOI wafer and process a piezoelectric component on a side of the device layer away from the buried oxide layer; Processing a pressure cavity on a side of the substrate layer away from the buried oxide layer; A first groove is processed on a side of the piezoelectric component away from the device layer, and along the direction from the piezoelectric component to the resonance component, at least a portion of the projection of the first groove falls within the projection range of the resonance cavity.

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