CN222635654U

CN222635654U - Piezoelectric resonant pressure sensor and compensation system

Info

Publication number: CN222635654U
Application number: CN202421474864.2U
Authority: CN
Inventors: 吴志鹏; 王锦瑜
Original assignee: Fuyuanxin Shanghai Technology Co ltd
Current assignee: Fuyuanxin Shanghai Technology Co ltd
Priority date: 2024-06-25
Filing date: 2024-06-25
Publication date: 2025-03-18
Anticipated expiration: 2034-06-25

Abstract

The present application provides a piezoelectric resonant pressure sensor and compensation system, which relates to the field of sensitive components and sensor manufacturing technology in the core electronics industry. The piezoelectric resonant pressure sensor includes a piezoelectric component, a resonant film, and a pressure resonant component. The resonant film is arranged on one side of the piezoelectric component and the resonant film is connected to the piezoelectric component. The pressure resonant component is arranged on one side of the resonant film and is connected to the resonant film. A resonant groove is arranged on the side of the pressure resonant component facing the resonant film, and the resonant groove cooperates with the resonant film to form a resonant cavity. A pressure cavity is arranged on the side of the pressure resonant component away from the resonant film. Among them, along the direction from the resonant film to the pressure resonant component, the projection of the resonant cavity at least partially falls within the projection range of the pressure cavity. According to the piezoelectric resonant pressure sensor provided in the example of the present application, the range of pressure measurement of the piezoelectric resonant pressure sensor can be expanded, thereby expanding the scope of use of the piezoelectric resonant pressure sensor.

Description

Piezoelectric resonant pressure sensor and compensation system

Technical Field

The application relates to the technical field of manufacturing of sensitive elements and sensors in the electronic core industry, in particular to a piezoelectric resonance type pressure sensor and a compensation system.

Background

The pressure sensor can convert the received pressure signal into an electric signal according to a certain rule and output the electric signal to other equipment, and belongs to a sensitive element. The pressure sensor is widely applied to the technical fields of national defense, automobiles, petroleum, aerospace, intelligent hardware and the like, and belongs to the technical field of electronic core industry.

With the development of Micro-Electro-MECHANICAL SYSTEM (MEMS) technology, the pressure sensor can be combined with MEMS technology to realize mass production of the pressure sensor, so that the production efficiency of the pressure sensor is improved.

Pressure sensors can be classified into piezoelectric resonance type pressure sensors, piezoresistive type pressure sensors, capacitive type pressure sensors, piezoelectric type pressure sensors, etc. according to the difference of the operating principle. The piezoelectric resonant pressure sensor has the advantages of high stability, high accuracy and the like, and is widely applied to high-accuracy requirements and severe environments, such as aerospace, petroleum and the like.

Based on the structure of the existing piezoelectric resonance type pressure sensor, the pressure detection range of the piezoelectric resonance type pressure sensor is smaller, and the application range of the piezoelectric resonance type pressure sensor can be possibly affected.

Disclosure of utility model

The application provides a piezoelectric resonance type pressure sensor, which is used for expanding the pressure detection range of the piezoelectric resonance type pressure sensor and expanding the application range of the piezoelectric resonance type pressure sensor.

A first aspect of the present application provides a piezoelectric resonant pressure sensor for use in the electronics core industry. The piezoelectric resonant pressure sensor includes a piezoelectric component, a resonant thin film, and a pressure resonant component.

Wherein the piezoelectric assembly is directly or indirectly connected with an external circuit. The resonant film is arranged on one side of the piezoelectric component, and the resonant film is directly or indirectly connected with the piezoelectric component. The pressure resonance component is arranged on one side of the resonance film and is connected with the resonance film, a resonance groove is formed in one side, facing the resonance film, of the pressure resonance component, the resonance film is arranged at an opening of the resonance groove, the resonance groove and the resonance film are matched to form a resonance cavity, a pressure cavity is formed in one side, facing away from the resonance film, of the pressure resonance component, and a pressure sensitive film is arranged between the resonance groove and the pressure cavity, and is used for receiving pressure to be detected. Wherein, along the direction of the resonant film to the pressure resonance component, the projection of the resonant cavity at least partially falls into the projection range of the pressure cavity.

According to the piezoelectric resonant pressure sensor provided by the example of the application, the pressure cavity can receive the pressure to be detected, the pressure to be detected can be transmitted to the piezoelectric component and the resonant film through the pressure resonant component, and the pressure to be detected is detected through the characteristics of the piezoelectric component. The piezoelectric assembly is arranged on one side of the resonant film, which is away from the pressure resonant assembly, so that the pressure cavities for receiving the pressure to be detected by the piezoelectric assembly are arranged at intervals. And the resonant groove of the pressure resonant assembly is matched with the resonant film to form a resonant cavity. Under the condition that the piezoelectric component drives the pressure resonance component to vibrate, the resonant cavity can provide deformation space for the piezoelectric component, so that the deformation of the piezoelectric component due to vibration is reduced, and the possibility of breakage of the piezoelectric component is further reduced.

Under the condition that the possibility of breakage of the piezoelectric component is reduced, the piezoelectric resonant pressure sensor provided by the example of the application can bear larger pressure to be detected, so that the range of pressure measurement of the piezoelectric resonant pressure sensor is increased, the measuring range of the piezoelectric resonant pressure sensor is enlarged, the application range of the piezoelectric resonant pressure sensor is enlarged, and the piezoelectric resonant pressure sensor 100 can be widely applied to the technical field of electronic core industry.

Furthermore, in the present example, the projection of the resonant cavity at least partially falls within the projection range of the pressure cavity, i.e. the resonant cavity at least partially coincides with the pressure cavity, due to the direction of the resonant film to the pressure resonant assembly. Based on the structure, the volume of the resonant piezoelectric sensor can be reduced, which is beneficial to miniaturization of the piezoelectric resonant pressure sensor and integration development of the piezoelectric resonant pressure sensor.

In some possible implementations, the connection between the resonant thin film and the pressure resonant assembly is provided with at least a partial oxide layer.

The oxide layer can ensure the insulativity between the resonant film and the pressure resonant assembly and ensure the use reliability of the piezoelectric resonant pressure sensor.

The oxidation layer can also reduce the influence of temperature in environmental factors on the piezoelectric resonant pressure sensor, and ensure the measurement accuracy of the resonant pressure sensor.

In some possible implementations, the resonant thin film is bonded to the pressure resonant assembly, and at least a portion of the oxide layer is formed at the bonded connection of the resonant thin film to the pressure resonant assembly.

The resonant film and the pressure resonant assembly may be joined together by anodic bonding, fusion bonding, or other bonding means. The oxidation layer formed at the bonding connection position of the resonance film and the pressure resonance component can ensure the connection reliability of the resonance film and the pressure resonance component, thereby ensuring the use reliability of the piezoelectric resonance type pressure sensor.

In some possible implementations, the resonant thin film is fabricated from an SOI wafer, the pressure resonant assembly is fabricated from a Si wafer, the device layer of the SOI wafer is bonded to the Si wafer, and at least a portion of the oxide layer is formed at the location of the bond between the SOI wafer and the Si wafer.

In some possible implementations, the projection of the resonant cavity falls within the projection range of the pressure cavity along the direction of the resonant film to the pressure resonant assembly.

Through along the direction of resonant cavity to pressure chamber, the projection of resonant cavity can fall into the projection scope of pressure chamber completely, like this, can further reduce piezoelectric resonance formula pressure sensor's volume, be favorable to piezoelectric resonance formula pressure sensor's miniaturization.

In some possible implementations, the pressure resonance assembly includes at least one connection structure provided on a side of the pressure resonance assembly facing the pressure sensitive membrane, the at least one connection structure cooperating with the pressure sensitive membrane to form a resonance groove.

The resonant cavity can provide vibration space for vibration of the piezoelectric component, and the possibility that the piezoelectric component is damaged due to deformation of the piezoelectric component caused by vibration is reduced. The connecting structure can directly or indirectly connect the pressure sensitive film and the piezoelectric component, and can change the acting direction of pressure to be detected, so that the pressure to be detected, which acts on the piezoelectric component vertically, is smaller, the possibility of damaging the piezoelectric component is reduced, the pressure bearing capacity of the resonant film is improved, the detection range of the piezoelectric resonant pressure sensor is enlarged, and the linearity of the piezoelectric resonant pressure sensor in the pressure detection range is ensured.

In some possible implementations, the pressure resonance assembly further includes at least one resonance substrate disposed on a side of the pressure resonance assembly facing away from the resonance membrane, the at least one resonance substrate cooperating with the pressure sensitive membrane to form a pressure chamber.

Through setting up the resonance substrate, resonance substrate and pressure sensitive film cooperation form the pressure chamber, and operating personnel can control fluid such as gas or liquid and exert pressure to the chamber wall in pressure chamber, can make the atress of pressure sensitive film comparatively concentrated through setting up the pressure chamber, and the operating personnel of being convenient for exerts the pressure of waiting to detect to the chamber wall in pressure chamber.

In some possible implementations, the piezoelectric resonant pressure sensor further includes a cover disposed on a side of the piezoelectric assembly facing away from the pressure resonant assembly, the cover being directly or indirectly connected to the piezoelectric assembly.

The sealing cover can isolate the piezoelectric assembly from the atmospheric environment, so that the piezoelectric assembly is in a vacuum environment during working, the value corresponding to the quality factor of the piezoelectric resonant pressure sensor is further improved, and the working performance of the piezoelectric resonant pressure sensor is guaranteed.

In some possible implementations, the piezoelectric resonant pressure sensor further includes a protective layer disposed on a side of the piezoelectric assembly facing away from the resonant assembly.

Through setting up the protective layer, can keep apart piezoelectric component and atmospheric environment, and the protective layer can play damp-proofing effect for resonant pressure sensor keeps in dry state as far as possible, guarantees resonant pressure sensor's operational reliability. The protective layer can also act as a temperature compensation during operation of the resonant pressure sensor.

A second aspect of the application provides a compensation system comprising a drive component, a detection component and a piezoelectric resonant pressure sensor as mentioned in any of the examples above, the at least two piezoelectric resonant pressure sensors comprising at least one pressure sensor and at least one compensation sensor.

Because the pressure sensor and the compensation sensor are integrated together, the pressure sensor and the compensation sensor have the same resonant film, environmental factors such as temperature, vibration, impact and the like can generate the same influence on the resonant film of the pressure sensor and the resonant film of the compensation sensor, and therefore the pressure sensor and the resonant film of the compensation sensor can have the same output based on the influence of the environmental factors.

Based on the above, when the detecting component detects the resonant frequency of the pressure sensor and the compensating sensor, the influence of environmental factors can be eliminated only by subtracting the resonant frequency output by the compensating sensor from the resonant frequency output by the pressure sensor and extracting the final resonant frequency, so that the accuracy of detecting the pressure to be detected by the compensating system is improved.

Drawings

Fig. 1 is a schematic structural diagram of a piezoelectric resonant pressure sensor according to an example of the present application.

Fig. 2 is a schematic top view of a piezoelectric resonant pressure sensor according to an exemplary embodiment of the present application.

Fig. 3 is a cross-sectional view of A-A in fig. 2.

Fig. 4 is a cross-sectional view of B-B of fig. 2.

Fig. 5 is a schematic structural diagram of another piezoelectric resonant pressure sensor according to an example of the present application.

Fig. 6 is a schematic top view of another piezoelectric resonant pressure sensor according to an example of the present application.

Fig. 7 is a cross-sectional view of fig. 6C-C.

Fig. 8 is a partial enlarged view at a in fig. 7.

Fig. 9 is a schematic diagram of an operating principle of a piezoelectric resonant pressure sensor according to an example of the present application.

Fig. 10 is a schematic diagram of a resonance principle of a piezoelectric resonant pressure sensor according to an example of the present application.

Fig. 11 is a schematic diagram of an internal structure of a piezoelectric resonant pressure sensor according to an example of the present application.

Fig. 12 is a schematic structural diagram of a piezoelectric resonant pressure sensor without a lead electrode and a protective layer according to an embodiment of the present application, where 4 lead bridges are provided.

Fig. 13 is a schematic structural diagram of a piezoelectric resonant pressure sensor without a lead electrode and a protective layer according to an embodiment of the present application, where 3 lead bridges are provided.

Fig. 14 is a schematic structural diagram of a piezoelectric resonant pressure sensor without a lead electrode and a protective layer according to an embodiment of the present application, where 2 lead bridges are provided.

Fig. 15 is a schematic structural diagram of a piezoelectric resonant pressure sensor without a lead electrode and a protective layer according to an embodiment of the present application, where 1 lead bridge is provided.

Fig. 16 is a schematic structural diagram of a piezoelectric resonant pressure sensor without a lead electrode and a protective layer according to an embodiment of the present application, where no lead bridge is provided.

Fig. 17 is a schematic structural diagram of another piezoelectric resonant pressure sensor according to an example of the present application.

Fig. 18 is a schematic structural diagram of a compensation system according to an example of the present application.

Fig. 19 is a schematic workflow diagram of a compensation system provided by an example of the application.

Reference numerals illustrate:

100. Piezoelectric resonant pressure sensor 110, piezoelectric component 111, first lead electrode 112, second lead electrode 113, first electrode 114, piezoelectric layer 115, second electrode 120, resonance layer 121, resonance film 122, first connecting part 123, second connecting part 130, pressure resonance component 131, resonance cavity 132, pressure cavity 133, pressure sensitive film 134, connecting structure 135, resonance substrate 136, resonance substrate 140, oxidation layer 150, protective layer 160, cover 170, groove 171, lead bridge 172, beam structure 200, compensation system 210, pressure sensor 220, compensation sensor 230, driving part 240, detection part.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present examples more apparent, the technical solutions in the present examples will be clearly and completely described below with reference to the accompanying drawings in the present examples, and it is apparent that the described examples are some, but not all examples of the present application. All other examples, which a person of ordinary skill in the art would obtain without undue burden based on the examples in this disclosure, are within the scope of this disclosure.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs, the terms used in the description of this application are used herein for the purpose of describing particular examples only and are not intended to limit the application, and the terms "comprise" and "have" and any variations thereof in the description of this application and the claims and drawings are intended to cover non-exclusive inclusions.

Reference herein to "an example" means that a particular feature, structure, or characteristic described in connection with the example may be included in at least one example of the application. The appearances of the phrase "in an example" in various places in the specification are not necessarily all referring to the same example, nor are separate or alternative examples mutually exclusive of other examples. Those skilled in the art will explicitly and implicitly understand that the examples described herein may be combined with other examples.

The term "and/or" is merely an association relation describing the association object, and means that three kinds of relations may exist, for example, a and/or B may mean that a exists, and a and B exist at the same time, and B exists. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

The directional terms appearing in the following description are directions shown in the drawings, and do not limit the specific structure of the piezoelectric resonant pressure sensor of the present application.

Furthermore, the terms first, second and the like in the description and in the claims or in the above-described figures, are used for distinguishing between different objects and not for describing a particular sequential order, and may be used to improve one or more of these features either explicitly or implicitly.

In the description of the present application, unless otherwise indicated, the meaning of "plurality" means two or more (including two), and similarly, "plural sets" means two or more (including two).

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and for example, the terms "connected" or "connected" of a mechanical structure may refer to a physical connection, for example, a physical connection may be a fixed connection, for example, a fixed connection by a spacer, for example, a fixed connection by a screw, a bolt, or other spacer, a physical connection may be a removable connection, for example, a snap-fit or snap-fit connection, and a physical connection may be an integral connection, for example, a welded, bonded, or integrally formed connection. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.

The resonant pressure sensor indirectly measures the pressure to be detected through measuring the resonant frequency change of the structure, has the advantages of high precision and good stability, and is suitable for scenes with high precision requirements and severe environments such as aerospace, oil and gas exploration and the like. The existing resonant pressure sensors include electrostatic excitation-resistance detection type resonant pressure sensors, piezoelectric excitation-piezoelectric detection type resonant pressure sensors, electromagnetic driving-electromagnetic detection type resonant pressure sensors, optical driving-optical detection type resonant pressure sensors, and resonant pressure sensors of quartz materials. The measurement structure may be a detection circuit or other structure capable of detecting the pressure to be detected.

The processing technology of the electrostatic excitation-resistance detection type resonant pressure sensor is simpler, but the circuit structure of the electrostatic excitation-resistance detection type resonant pressure sensor is more complex because the piezoresistance detection needs to use a Wheatstone bridge, and the processing requirements of the electrostatic excitation-resistance detection type resonant pressure sensor are higher for the consistency of piezoresistors.

The piezoelectric excitation-resistance detection type resonant pressure sensor is similar to the electrostatic excitation-resistance detection type, and the problems of complex circuit structure and higher consistency requirement of piezoresistors are also existed.

The electromagnetic drive-electromagnetic detection type resonant pressure sensor utilizes the periodic vibration generated by the time-varying Lorentz force of a harmonic oscillator in an excitation electromagnetic field, and then utilizes the inverse process of electromagnetic drive to detect the vibration. This approach requires the addition of sensor peripherals to provide the magnetic field due to the need for electromagnetic fields, and the sensor is not easily miniaturized.

Based on the foregoing, an example of the present application provides a piezoelectric resonant pressure sensor and a compensation system.

The piezoelectric resonant pressure sensor according to the example of the application can be combined with MEMS technology to realize mass production of the piezoelectric resonant pressure sensor and improve the production efficiency of the piezoelectric resonant pressure sensor.

The piezoelectric resonant pressure sensor provided by the example of the application can output corresponding electric signals based on the received pressure to be detected, and belongs to sensitive elements.

In order to better understand the solution of the present application, the following description will clearly and completely describe the piezoelectric resonant pressure sensor and the compensation system provided by the examples of the present application with reference to the accompanying drawings.

Fig. 1 is a schematic structural view of a piezoelectric resonant pressure sensor according to an embodiment of the present application, fig. 2 is a top view of a schematic structural view of a piezoelectric resonant pressure sensor according to an embodiment of the present application, fig. 3 is a cross-sectional view A-A of fig. 2, fig. 4 is a cross-sectional view B-B of fig. 2, and referring to fig. 1 to 4, a piezoelectric resonant pressure sensor 100 includes a piezoelectric component 110, a resonant film 121, and a pressure resonant component 130.

The piezoelectric element 110 is directly or indirectly connected to an external circuit. The resonant thin film 121 is provided at one side of the piezoelectric element 110, and the resonant thin film 121 is directly or indirectly connected to the piezoelectric element 110. The pressure resonance assembly 130 is arranged on one side of the resonance film 121 and is connected with the resonance film 121, a resonance groove is formed in one side, facing the resonance film 121, of the pressure resonance assembly 130, the resonance film 121 is arranged on an opening of the resonance groove, the resonance groove is matched with the resonance film 121 to form a resonance cavity 131, a pressure cavity 132 is formed in one side, facing away from the resonance film 121, of the pressure resonance assembly 130, a pressure sensitive film 133 is arranged between the resonance groove and the pressure cavity 132, and the pressure cavity 132 is used for receiving pressure to be detected. Wherein, along the direction from the resonant film 121 to the pressure resonant assembly 130, the projection of the resonant cavity 131 at least partially falls within the projection range of the pressure cavity 132.

Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the pressure chamber 132 may receive the pressure to be detected, and since the pressure chamber 132 is disposed at a side of the pressure resonant assembly 130 facing away from the resonant thin film 121 and the pressure resonant assembly 130 is directly or indirectly connected with the resonant thin film 121, the pressure to be detected can be transmitted to the resonant thin film 121 through the pressure resonant assembly 130. Since the resonant film 121 is disposed at one side of the piezoelectric element 110, the resonant film 121 is directly or indirectly connected to the piezoelectric element 110, and the pressure to be detected indirectly acting on the resonant film 121 can be transferred to the piezoelectric element 110.

Next, the structure of the piezoelectric resonant pressure sensor 100 will be described in detail.

The pressure resonance assembly 130 may be provided with a resonance groove, a pressure sensitive film 133 may be formed on a side of the pressure resonance assembly 130 facing away from an opening of the resonance groove, and a pressure cavity 132 may be formed on a side of the pressure sensitive film 133 facing away from the resonance groove.

The pressure resonance assembly 130 may also be provided with a resonance groove and other connection structures, and a pressure sensitive film 133 may be formed on a side of the pressure resonance assembly 130 facing away from the opening of the resonance groove, and the pressure sensitive film 133 may cooperate with the other connection structures to form the pressure cavity 132. The present example is not limited to a particular implementation of pressure chamber 132.

The pressure to be sensed received by the pressure chamber 132 may be the pressure applied directly or indirectly to the pressure resonant assembly 130 by a fluid, which may be a liquid, a gas, or the like.

The resonant film 121 may be directly or indirectly connected to the side of the pressure resonant assembly 130 facing away from the pressure cavity 132, and the resonant film 121 is disposed at an opening of the resonant groove, where the resonant film 121 may close the opening of the resonant groove, and the resonant film 121 may also be provided with a through hole that does not close the opening of the resonant grass, and the resonant film 121 and the resonant groove cooperate to form the resonant cavity 131.

The piezoelectric assembly 110 is arranged on one side of the resonant film 121 away from the pressure resonant assembly 130, and the pressure to be detected, which acts on the pressure resonant assembly 130, can indirectly act on the piezoelectric assembly 110 through the pressure resonant assembly 130 and the resonant film 121, and the pressure to be detected can be detected through the piezoelectric assembly 110.

Illustratively, the piezoelectric assembly 110 may include a piezoelectric layer 114 and electrodes, and the piezoelectric layer 114 may be made of a thin film material such as AlN, scAlN, PZT (piezoelectric ceramic), znO, liNbO ₃, or the like. Due to piezoelectricity of the piezoelectric film material, under the condition that the piezoelectric layer 114 receives pressure, potential difference can be generated on two sides of the piezoelectric layer 114 which are oppositely arranged, vibration of the piezoelectric resonant pressure sensor 100 can be detected by utilizing positive piezoelectric effect and inverse piezoelectric effect of the piezoelectric layer 114, and further relevant parameters of the pressure to be detected are known, wherein the relevant parameters can include numerical value of the pressure to be detected, direction parameters of the pressure to be detected and the like.

The electrode can be directly and electrically connected with the external circuit, and the electrode can be indirectly connected with the external circuit through conducting pieces such as wires.

The external circuit can be a circuit for detecting the current and a circuit for detecting the voltage. The specific type of the external circuit is not limited by the present example, as long as the external circuit is guaranteed to be able to detect the electrical signal output by the piezoelectric assembly 110.

The resonant film 121 may be directly or indirectly connected to a side of the pressure resonant assembly 130 facing away from the pressure chamber 132, and the resonant film 121 may be disposed at an opening of the resonant recess, and the resonant film 121 and the resonant recess may cooperate to form the resonant chamber 131.

Along the direction of the resonant film 121 to the pressure resonant assembly 130, the projection of the resonant cavity 131 falls at least partially within the projection range of the pressure cavity 132.

The projection of the resonant cavity 131 may completely fall within the projection range of the pressure cavity 132, and at this time, the geometric center of the projection of the resonant groove may overlap with the geometric center of the projection of the pressure cavity 132, and a distance may exist between the geometric center of the resonant groove and the geometric center of the pressure cavity 132.

The partial projection of the resonant cavity 131 may also fall within the projection range of the pressure cavity 132, that is, the projection of the resonant cavity 131 coincides with the projection portion of the pressure cavity 132.

The shape of the pressure chamber 132 may be the same as the shape of the resonance groove, and the shape of the pressure chamber 132 may be different from the shape of the resonance groove. The present example is described herein with reference to pressure chamber 132 only. For example, the shape of the pressure chamber 132 may be cylindrical, the shape of the pressure chamber 132 may be prismatic, or the shape of the pressure chamber 132 may be irregular.

The pressure chambers 132 may be provided in one or more than one pressure chamber 132 at intervals. The resonance groove may be provided only one, or may be provided in plurality, and the present example is not limited thereto.

The positional relationship between the resonant groove and the pressure cavity 132 is not particularly limited in the present embodiment, so long as the projection of at least part of the resonant cavity 131 coincides with the projection of the pressure cavity 132, so as to ensure that the pressure to be detected received by the pressure cavity 132 can be transmitted to the piezoelectric component 110 through the resonant groove, and the pressure to be detected can be detected through the piezoelectric component 110.

Based on the above, according to the piezoelectric resonant pressure sensor 100 provided by the example of the present application, the pressure chamber 132 can receive the pressure to be detected, which can be transmitted to the piezoelectric assembly 110 and the resonant thin film 121 through the pressure resonant assembly 130, and the pressure to be detected can be detected by the characteristics of the piezoelectric assembly 110. Since the piezoelectric assembly 110 is disposed on the side of the resonant thin film 121 facing away from the pressure resonant assembly 130, the piezoelectric assembly 110 is spaced apart from the pressure chamber 132 receiving the pressure to be detected. And the resonant cavity 131 is formed by the resonant groove of the pressure resonant assembly 130 cooperating with the resonant thin film 121. Under the condition that the piezoelectric assembly 110 drives the pressure resonance assembly 130 to vibrate, the resonant cavity 131 can provide a deformation space for the piezoelectric assembly 110, so that the possibility of damage to the piezoelectric assembly 110 due to large deformation of the piezoelectric assembly 110 caused by vibration is reduced.

Under the condition that the possibility of breakage of the piezoelectric component 110 is reduced, the piezoelectric resonant pressure sensor 100 provided by the example of the application can bear larger pressure to be detected, so that the range of pressure measurement of the piezoelectric resonant pressure sensor 100 is increased, the measuring range of the piezoelectric resonant pressure sensor 100 is enlarged, the application range of the piezoelectric resonant pressure sensor 100 is enlarged, and the piezoelectric resonant pressure sensor 100 can be widely applied to the technical field of electronic core industry.

Furthermore, in the present example, since the projection of the resonant cavity 131 falls at least partially within the projection range of the pressure cavity 132 in the direction of the resonant film 121 to the pressure resonant assembly 130, i.e., the resonant cavity 131 at least partially coincides with the pressure cavity 132. Based on this, the volume of the resonant piezoelectric sensor can be reduced, which is advantageous for miniaturization of the piezoelectric resonant pressure sensor 100 and for the development of integration of the piezoelectric resonant pressure sensor 100.

Based on the piezoelectric resonant pressure sensor 100 provided by the above example, the projection of the resonant cavity 131 falls within the projection range of the pressure cavity 132 in the direction from the resonant thin film 121 to the pressure resonant assembly 130.

Through along the direction of resonant cavity 131 to pressure cavity 132, the projection of resonant cavity 131 can fall into the projection scope of pressure cavity 132 completely, like this, can further reduce the volume of piezoelectric resonance formula pressure sensor 100, be favorable to piezoelectric resonance formula pressure sensor 100's miniaturization, be favorable to piezoelectric resonance formula pressure sensor 100's integration development.

Based on the piezoelectric resonant pressure sensor 100 provided in the above example, referring to fig. 4, at least a part of the oxide layer 140 is disposed at the connection between the resonant thin film 121 and the pressure resonant assembly 130.

The oxide layer 140 may be used to connect the resonant thin film 121 with the pressure resonant assembly 130. The oxide layer 140 may be a connection part formed during the connection of the resonant thin film 121 and the pressure resonance assembly 130. The oxide layer 140 may also be a connection member purposely provided between the resonant thin film 121 and the pressure resonance assembly 130.

Both the resonant thin film 121 and the pressure resonant assembly 130 may be made of silicon or other semiconductor materials. The oxide layer 140 may be made of silicon oxide or other materials, and the material of the oxide layer 140 may be different depending on the manufacturing materials of the resonant thin film 121 and the pressure resonance assembly 130, and the specific arrangement of the oxide layer 140 is not limited in the present example.

The present example is described only with respect to the resonant thin film 121 and the pressure resonant member 130 being made of a silicon material, and the oxide layer 140 being made of a silicon oxide material. Compared with silicon materials, silicon oxide materials have better insulativity and lower thermal conductivity.

In summary, the oxide layer 140 can ensure insulation between the resonant thin film 121 and the pressure resonant assembly 130, and ensure the reliability of the piezoelectric resonant pressure sensor 100.

The oxide layer 140 can also reduce the influence of temperature in environmental factors on the piezoelectric resonant pressure sensor 100, and ensure the measurement accuracy of the resonant pressure sensor.

Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the resonant thin film 121 is bonded to the pressure resonant assembly 130, and at least a part of the oxide layer 140 is formed at the bonding connection between the resonant thin film 121 and the pressure resonant assembly 130.

The resonant membrane 121 and the pressure resonant assembly 130 may be joined together by anodic bonding, fusion bonding, or other bonding means. The oxide layer 140 formed at the bonding connection position of the resonant film 121 and the pressure resonant assembly 130 can ensure the connection reliability of the resonant film 121 and the pressure resonant assembly 130, thereby ensuring the use reliability of the piezoelectric resonant pressure sensor 100.

Based on the piezoelectric resonant pressure sensor 100 provided by the above example, the resonant thin film 121 is processed from an SOI wafer, the pressure resonant assembly 130 is processed from an Si wafer, the device layer of the SOI wafer is bonded to the Si wafer, and at least a part of the oxide layer 140 is formed at the bonding position of the SOI wafer and the Si wafer.

The SOI wafer may include a device layer, an oxygen-buried layer, and a substrate layer, wherein the thickness of the device layer may be equal to the thickness of the resonant thin film 121, and the thickness of the device layer may be smaller than the thickness of the Yu Xiezhen thin film 121, as long as the processing of the resonant thin film 121 based on the SOI wafer is ensured. The resonant thin film 121 may include only a device layer, the resonant thin film 121 may also include a device layer and at least a portion of an oxygen-buried layer, or the resonant thin film 121 may also include a device layer, an oxygen-buried layer, and at least a portion of a substrate layer, and the specific implementation of the resonant thin film 121 is not limited by the present examples.

The device layer is disposed close to the Si wafer with respect to the whole SOI wafer, and therefore, when the SOI wafer and the Si wafer are bonded, the bonding connection position of the SOI wafer and the Si wafer is between the device layer and the Si wafer.

The bonding connection manner is similar to the bonding connection manner described above, and functions similarly, and the present disclosure is not repeated here.

Based on the piezoelectric resonant pressure sensor 100 provided by the above example, fig. 5 is a schematic structural diagram of another piezoelectric resonant pressure sensor provided by the example of the present application, fig. 6 is a schematic structural diagram of another piezoelectric resonant pressure sensor provided by the example of the present application, fig. 7 is a cross-sectional view C-C in fig. 6, fig. 8 is a partial enlarged view of a portion a in fig. 7, and referring to fig. 5 to 8, the pressure resonant assembly 130 may include at least one connection structure 134, where the connection structure 134 is disposed on a side of the pressure resonant assembly 130 facing the pressure sensitive film 133, and the at least one connection structure 134 cooperates with the pressure sensitive film 133 to form a resonant groove.

The connecting structure 134 may be cylindrical, prismatic, frustoconical, or otherwise shaped. The connection structure 134 may be provided with at least one, and the connection structure 134 may be provided with two, three, or even more.

The connection structure 134 may be formed integrally with the pressure sensitive membrane 133, in which case the resonant recess may be a recess formed by removing the middle portion of a block-like structure. The pressure sensitive film 133 may be a partial block structure corresponding to the bottom wall of the resonance groove. The connection structure 134 may be a partial block structure corresponding to a groove sidewall of the resonance groove.

The connection structure 134 may also be connected to the pressure sensitive membrane 133 by bonding or other connection means, in which case the connection structure 134 may include a plurality of connection structures 134, and different connection structures 134 may be capable of being connected to the side walls of the corresponding pressure sensitive membrane 133. In this case, the pressure sensitive film 133 may be used as a bottom wall of the resonant cavity, and the connection structure 134 may be used as a side wall of the resonant cavity, where the pressure sensitive film 133 and the connection structure 134 together enclose the resonant cavity.

The resonance film 121 may be provided at a circumferential side thereof with at least one first connection portion 122, the at least one first connection portion 122 may be disposed between the piezoelectric element 110 and the connection structure 134, and the first connection portion 122 may be capable of connecting the piezoelectric element 110 and the connection structure 134. Therefore, the connection structure 134 may be connected to the piezoelectric assembly 110 through the first connection portion 122 connection.

The at least one first connection portion 122 and the resonant film 121 may cooperate to form the resonant layer 120, and the resonant layer 120 may further include other components, such as a second connection portion 123, and a specific structure of the second connection portion 123 is described in detail below.

Based on the above, since one side of the connection structure 134 is provided with the pressure sensitive film 133, the other side of the connection structure 134 is directly or indirectly connected with the piezoelectric assembly 110. Based on this, the pressure to be detected acting on the pressure sensitive film 133 may be transferred to the resonant film 121 and the piezoelectric element 110 through the connection structure 134, and stress is generated in the resonant film 121 and the piezoelectric element 110, thereby causing a change in the vibration frequency of the resonant film 121 and the piezoelectric element 110. Since the resonant cavity 131 is disposed on one side of the piezoelectric assembly 110, the resonant cavity 131 can provide a vibration space for the vibration of the piezoelectric assembly 110, and reduce the possibility of damage to the piezoelectric assembly 110 caused by deformation of the piezoelectric assembly 110 due to the vibration.

Fig. 9 is a schematic diagram illustrating an operation principle of a piezoelectric resonant pressure sensor according to an embodiment of the present application, and referring to fig. 9, a connection structure 134 can change a direction of an action of a pressure to be detected.

Illustratively, the pressure to be detected acts on the pressure sensitive film 133 along a direction perpendicular to the pressure sensitive film 133, and the pressure to be detected acting on the pressure sensitive film 133 can be transferred to the resonant film 121 through the connection structure 134, and the connection structure 134 can convert the pressure to be detected perpendicular to the pressure sensitive film 133 into an operating stress having an included angle between an acting direction and an acting direction of the pressure to be detected.

In summary, the resonant cavity 131 can provide a vibration space for the vibration of the piezoelectric assembly 110, so as to reduce the possibility of damage to the piezoelectric assembly 110 caused by deformation of the piezoelectric assembly 110 due to the vibration. The connection structure 134 can directly or indirectly connect the pressure sensitive film 133 and the piezoelectric assembly 110, and the connection structure 134 can change the acting direction of the pressure to be detected, so that the pressure to be detected acting on the piezoelectric assembly 110 vertically is smaller, the possibility of damaging the piezoelectric assembly 110 is reduced, the pressure bearing capacity of the resonant film 121 is improved, the detection range of the piezoelectric resonant pressure sensor 100 is enlarged, and the linearity of the piezoelectric resonant pressure sensor 100 in the pressure detection range is ensured.

The piezoelectric resonant pressure sensor 100 mentioned in the above example may be a vacuum chamber, and the chamber may be filled with a medium.

The piezoelectric resonant pressure sensor 100 may be an absolute pressure sensor, for example. The absolute pressure sensor is used for measuring absolute pressure, and can convert the absolute pressure of gas or liquid into equivalent electric signal output.

Illustratively, the piezoelectric resonant pressure sensor 100 may be a relative pressure sensor. The relative pressure sensor is measured based on the atmospheric pressure, and therefore, the measurement result of the relative pressure sensor is relative to the atmospheric pressure. Therefore, a relative pressure sensor may be used to measure the difference in relative pressure.

A user may select an appropriate absolute pressure sensor or a relative pressure sensor according to needs, and the present application is not limited by whether the medium is injected into the resonant cavity 131.

Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the side of the connection structure 134 near the pressure sensitive film may be an anchor point, the distance between the anchor point and the resonant film 121 is a first distance, the distance between the anchor point and the pressure sensitive film is a second distance, and the first distance is greater than the second distance.

The anchor point is the primary point of stress for the connection structure 134.

By setting the first distance to be greater than the second distance, the resonant membrane 121, the pressure sensitive membrane, and the anchor point may cooperate to form a lever, where the first distance is a first lever arm and the second distance is a second lever arm. Based on the lever principle, the connecting structure 134 with the anchor point can amplify the working stress generated by the pressure to be detected, thereby improving the detection sensitivity of the piezoelectric resonant pressure sensor 100.

Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the pressure resonant assembly 130 further includes at least one resonant substrate 136, where the resonant substrate 136 is disposed on a side of the pressure resonant assembly 130 facing away from the resonant film 121, and the at least one resonant substrate 136 cooperates with the pressure sensitive film 133 to form the pressure cavity 132.

The resonant substrate 136 may be of unitary construction with the pressure sensitive membrane 133, in which case the pressure chamber 132 may be a cavity formed by a block-like structure with intermediate portions removed. The pressure sensitive membrane 133 may be a corresponding partial block-like structure of the cavity bottom of the pressure cavity 132. The resonant substrate 136 may be a partial block structure corresponding to the side walls of the pressure chamber 132.

The resonant substrate 136 may also be bonded or otherwise coupled to the pressure sensitive membrane 133, in which case the resonant substrate 136 may include a plurality of different resonant substrates 136 capable of being coupled to the sidewalls of the corresponding resonant membranes 121. In this case, the pressure sensitive film 133 may serve as a bottom wall of the pressure chamber 132, the resonant substrate 136 may serve as a side wall of the pressure chamber 132, and the pressure sensitive film 133 and the resonant substrate 136 may jointly enclose the pressure chamber 132.

Through setting up resonant substrate 136, resonant substrate 136 and pressure sensitive film 133 cooperate to form pressure chamber 132, and operating personnel can control fluid such as gas or liquid and exert pressure to the chamber wall of pressure chamber 132, can make the atress of pressure sensitive film 133 comparatively concentrated through setting up pressure chamber 132, and the operating personnel of being convenient for exerts the pressure of waiting to detect to the chamber wall of pressure chamber 132.

In the present example, the resonant substrate 136, the connection structure 134, the pressure sensitive film 133, and other structures of the pressure resonant assembly 130 may be integrally formed, so that the processing technology of the piezoelectric resonant pressure sensor 100 may be reduced, and the processing cost of the piezoelectric resonant pressure sensor 100 may be reduced.

Based on the piezoelectric resonant pressure sensor 100 provided by the above example, fig. 10 is a schematic diagram of a resonance principle of the piezoelectric resonant pressure sensor provided by the example of the present application, referring to fig. 1 to 6 and fig. 10, the piezoelectric component 110 may include a first lead electrode 111, a second lead electrode 112, a first electrode 113, a piezoelectric layer 114 and a second electrode 115.

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

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

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

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

The first electrode 113 and the second electrode 115 may have the same shape or different shapes. The present example is described using the first electrode 113 as an example, and the first electrode 113 may have any of other regular shapes such as a cylindrical shape, a prismatic shape, and the like, or may have an irregular shape.

The first lead electrode 111 and the second lead electrode 112 may have the same shape or different shapes. Only the first lead electrode 111 will be described here as an example.

Illustratively, the first lead electrode 111 may include a first portion and a second portion connected to each other, one end of the first portion being connected to the first electrode 113, and one end of the second portion being connected to an external circuit. The cross-sectional shapes of the first and second portions may be the same or different, for example, the cross-sectional shape of the first portion may be circular, elliptical, polygonal, or irregular. The present example is not limited to a specific implementation of the first electrode 113, the second electrode 115, and the first lead electrode 111 and the second lead electrode 112.

The second electrode 115 may be a conductive layer laid on the side of the resonant film 121 facing away from the resonant recess, and the second electrode 115 may be provided with only one. The second electrode 115 may be used to implement the ground of the piezoelectric resonant pressure sensor 100.

The side of the second electrode 115 facing away from the resonance film 121 may be provided with a piezoelectric layer 114.

The first electrode 113 may be provided at a side of the piezoelectric layer 114 facing away from the second electrode 115, and the first electrode 113 may be provided with at least two. The first electrode 113 may include at least one driving electrode and at least one detecting electrode. The driving electrode is used for driving the piezoelectric layer 114 to vibrate, and the detecting electrode is used for detecting the vibration of the piezoelectric layer 114.

The external circuit may be a detection circuit for detecting an output electric signal of the piezoelectric resonant pressure sensor 100. The first portion of the external circuit may be an input portion of the external circuit, and the second portion of the external circuit may be an output portion of the external circuit.

Next, referring to fig. 9 and 10, the principle of the piezoelectric resonant pressure sensor 100 will be further described with reference to the specific structure of the piezoelectric assembly 110.

The resonant thin film 121, the resonant cavity 131, the connection structure 134, and the piezoelectric assembly 110 cooperate with each other to form a piezoelectric resonator, which may also include other structures.

When any one of the first electrodes 113 receives a voltage, stress is generated in the piezoelectric layer 114 due to the inverse piezoelectric effect of the piezoelectric layer 114. At this time, the neutral layer of the piezoelectric layer 114 deviates from the geometric center position of the piezoelectric layer 114, which will cause the piezoelectric layer 114 to deform, and the deformation of the piezoelectric layer 114 drives the entire piezoelectric resonator to deform.

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

Where f _r is the resonant frequency, μ _n is a constant set when solving the Bessel function, t is the thickness, r is the radius, E is the Young's modulus, ρ is the density, and δ is the Poisson's ratio.

In the case that the pressure chamber 132 receives the pressure to be detected, the pressure sensitive film 133 is deformed and generates an operating stress under the action of the pressure to be detected. The connection structure 134 may transfer the deformation and resulting operational stress of the pressure sensitive membrane 133 to the piezoelectric resonator, and in particular to the piezoelectric layer 114. During the transfer of the connection structure 134, the connection structure 134 can change the acting direction of the pressure to be detected, so as to reduce the possibility of damage to the resonant thin film 121. The anchor point can amplify the working stress by using the lever principle, and improves the measurement range of the piezoelectric resonant pressure sensor 100.

Since the piezoelectric resonator is provided with at least two first electrodes 113, in the case where one of the first electrodes 113 drives the piezoelectric layer 114 to vibrate, the other first electrode 113 detects the vibration of the piezoelectric resonator. The first electrode 113 receiving the voltage may be a driving electrode, and the first electrode 113 detecting the vibration may be a detecting electrode.

The detection electrode will generate an electrical signal due to the positive piezoelectric effect of the piezoelectric film material. The electrical signal may be used to detect the resonant frequency of the piezoelectric resonator.

Let the working stress of the pressure to be detected on the piezoelectric resonator be sigma, at this time, the resonance frequency of the piezoelectric resonator is:

From the above formula, the pressure value can be determined when the frequency change of the piezoelectric resonator is detected.

In the case where the piezoelectric layer 114 is deformed, a portion of the piezoelectric layer 114 near the resonance film 121 is pressed by the pressure to be detected, and a portion of the piezoelectric layer 114 away from the resonance film 121 is stretched by the pressure to be detected. The transition layer, which is present between the piezoelectric layer 114 of the tensile portion and the piezoelectric layer 114 of the compressive portion and is neither in tension nor in compression, with almost zero stress, is the neutral layer mentioned above in the cross section of the piezoelectric layer 114.

Compared with the resistance detection type piezoelectric sensor which needs to be provided with a Wheatstone bridge and the capacitance detection type pressure sensor which needs to be provided with a capacitance bridge, the piezoelectric resonance type pressure sensor 100 provided by the example of the application does not need to be provided with an extra detection circuit, and has simpler structure and lower manufacturing cost.

Based on the piezoelectric resonant pressure sensor 100 provided by the above example, fig. 11 is a schematic diagram of an internal structure of the piezoelectric resonant pressure sensor provided by the example of the present application. Fig. 3, 7 and 11 are schematic views showing the internal structure of the piezoelectric resonant pressure sensor 100 having different structures. Fig. 3 is a diagram for illustrating an internal structure of the piezoelectric resonator type pressure sensor 100 when the piezoelectric resonator type pressure sensor 100 is not provided with a groove, fig. 7 is a diagram for illustrating an internal structure of the piezoelectric resonator type pressure sensor 100 when the piezoelectric resonator type pressure sensor 100 is provided with one groove, and fig. 11 is a diagram for illustrating an internal structure of the piezoelectric resonator type pressure sensor 100 when the piezoelectric resonator type pressure sensor 100 is provided with another groove.

Referring to fig. 7 or 11, at least one groove 170 is provided on the piezoelectric resonant pressure sensor 100. The groove 170 may be provided between the resonance film 121 and the pressure sensitive film 133. Alternatively, the groove 170 may be disposed on a side of the resonant film 121 facing away from the resonant substrate 136, and an opening of the groove 170 may be opened facing away from the resonant substrate 136.

For example, referring to fig. 11, the resonant film 121 may further include a resonant substrate 135, where the resonant substrate 135 is disposed on a side of the pressure resonant assembly 130 facing away from the pressure chamber 132. The resonant substrate 135 may be connected to the piezoelectric layer through the second connection part 123.

A partial oxide layer may be located between the second connection portion 123 and the resonant substrate 135 to ensure connection reliability of the second connection portion 123 and the resonant substrate 135.

The groove 170 may be provided between the resonant thin film 121 and the pressure sensitive thin film 133 in a direction in which the resonant thin film 121 faces the pressure resonant assembly 130. The groove 170 is provided between the resonant substrate 135 and the connection structure 134 in the direction of the cross section of the resonant recess.

The groove 170 can keep a distance between the resonant substrate 135 and the connection structure 134, so as to reduce the cross-sectional area of the connection structure 134, and make the working stress transferred to the pressure sensitive film 133 through the connection structure 134 more concentrated, which is beneficial to improving the detection accuracy of the piezoelectric resonant pressure sensor 100.

For example, referring to fig. 7, the resonant film 121 may further include a resonant substrate 135, and the resonant substrate 135 may be disposed in a similar manner to the resonant substrate 135 mentioned in the previous example, and the present application will not be described herein.

The groove 170 may also be disposed on a side of the resonant film 121 facing away from the resonant substrate 136, and an opening of the groove 170 opens away from the resonant substrate 136.

The grooves 170 in the present embodiment can maintain a distance between the resonant substrate 135 and the connection structure 134, thereby reducing the cross-sectional area of the connection structure 134, so that the working stress transferred to the pressure sensitive film 133 through the connection structure 134 is concentrated, which is beneficial to improving the detection accuracy of the piezoelectric resonant pressure sensor 100.

Furthermore, since the opening of the groove 170 is facing away from the resonant substrate 136, the opening of the groove 170 may be opened to a position where the piezoelectric element 110 is located, and in particular, may be opened to a side of the piezoelectric element 110 facing away from the resonant film 121. Based on this, the resonant thin film 121 may divide the piezoelectric layer 114 into at least two parts, and along the direction from the resonant recess to the pressure chamber 132, the projection of the groove 170 is located between the projection of the at least one lead electrode and the projection of the resonant chamber 131, i.e., the groove 170 may divide the piezoelectric element 110 into a part that vibrates under the pressure to be detected and a part that hardly vibrates under the pressure to be detected, and the at least one lead electrode may be located at the part of the piezoelectric element 110 that hardly vibrates. In this way, the influence of the pressure to be detected on the lead electrode can be reduced, the possibility of vibration of the lead electrode under the action of the pressure to be detected is reduced, and the use reliability of the piezoelectric resonant pressure sensor 100 is further ensured.

By providing the grooves 170, a lead bridge 171 may be formed between two adjacent grooves 170, and the lead bridge 171 may have a cross shape, a rice shape, a straight shape, or other irregular shape.

The number of the lead bridges 171 may be equal to and one-to-one corresponding to the number of the first lead electrodes 111, and the number of the lead bridges 171 may be less than the number of the first lead bridges 171, which is not limited by the present example. Specifically, referring to fig. 12 to fig. 16, fig. 12 is a schematic structural diagram of a piezoelectric resonant pressure sensor without a lead electrode and a protective layer according to an example of the present application, where the structure is provided with 4 lead bridges. Fig. 13 is a schematic structural diagram of a piezoelectric resonant pressure sensor without a lead electrode and a protective layer according to an embodiment of the present application, where 3 lead bridges are provided. Fig. 14 is a schematic structural diagram of a piezoelectric resonant pressure sensor without a lead electrode and a protective layer according to an embodiment of the present application, where 2 lead bridges are provided. Fig. 15 is a schematic structural diagram of a piezoelectric resonant pressure sensor without a lead electrode and a protective layer according to an embodiment of the present application, where 1 lead bridge is provided. Fig. 16 is a schematic structural diagram of a piezoelectric resonant pressure sensor without a lead electrode and a protective layer according to an embodiment of the present application, where no lead bridge is provided.

By providing the lead bridge 171, a setting position can be provided for a lead wire connecting the first lead electrode 111 and the first electrode 113, and the setting position of the first lead electrode 111 is adjusted, so that the connection reliability of the first lead electrode 111 and the first electrode 113 is ensured.

Referring to fig. 12, a beam structure 172 may be disposed at a location where the first electrode 113 is disposed, and one or more beam structures 172 may be disposed. The plurality of beam structures 172 may be cross-shaped, zig-zag, in-line, or other irregular shapes.

An angle may be formed between beam structure 172 and lead bridge 171.

Illustratively, the included angle between the beam structure 172 and the lead bridge 171 may be equal to zero, i.e., the connection electrode between the first lead electrode 111 and the first electrode 113 may be linear, and the connection electrode may be provided to the lead bridge 171 to electrically connect the first lead electrode 111 and the first electrode 113. At this time, the number of beam structures 172 may be equal to or different from the number of lead bridges 171. For example, in the case where the number of beam structures 172 and the number of lead bridges 171 are equal, the beam structures 172 and the lead bridges 171 may cooperate to form a straight-line structure, a cross-shaped structure, a rice-shaped structure, or other structures.

Illustratively, the angle between the beam structure 172 and the lead bridge 171 may also be a non-zero angle, i.e., the connection electrode between the first lead electrode 111 and the first electrode 113 is in the shape of a meander. At this time, the number of beam structures 172 may be equal to or unequal to the number of lead bridges 171. The present examples are not limited to the specific implementation of beam structure 172 and lead bridge 171.

Based on the piezoelectric resonant pressure sensor 100 provided in the above example, the piezoelectric component 110 may further include a seed layer disposed between the piezoelectric component 110 and the resonant thin film 121, and in particular, may be disposed between the second electrode 115 and the resonant thin film 121.

By providing the seed layer, the operation performance of the piezoelectric component 110 can be ensured, and thus the operation performance of the piezoelectric resonant pressure sensor 100 can be ensured.

Based on the piezoelectric resonant pressure sensor 100 provided by the above example, fig. 17 is a schematic structural diagram of another piezoelectric resonant pressure sensor provided by the example of the present application, referring to fig. 17, the piezoelectric resonant pressure sensor 100 may further include a cover 160, where the cover 160 is disposed on a side of the resonant thin film 121 facing away from the pressure resonant assembly 130, and the cover 160 is directly or indirectly connected to the resonant thin film 121.

The cover 160 may be made of a silicon wafer, a glass wafer, an inorganic semiconductor material, or other amorphous inorganic nonmetallic material.

The cover 160 may be used to encapsulate the piezoelectric resonator in a vacuum environment. The cover 160 may be disposed on a side of the piezoelectric assembly 110 away from the resonant film 121, so as to isolate the piezoelectric assembly 110 from the atmospheric environment, ensure that the piezoelectric assembly 110 is in a vacuum environment during operation, further 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.

Based on the piezoelectric resonant pressure sensor 100 provided in the above example, referring to fig. 4, a side of the piezoelectric assembly 110 facing away from the resonant film 121 may be provided with a protective layer 150, and the protective layer 150 may be made of a silicon dioxide material or other material capable of preventing moisture.

The protective layer 150 can isolate the piezoelectric assembly 110 from the atmospheric environment, and the protective layer 150 can play a role in moisture prevention, so that the piezoelectric resonant pressure sensor 100 is maintained in a dry state as much as possible, and the working reliability of the piezoelectric resonant pressure sensor 100 is ensured. The protective layer 150 may also function as temperature compensation during operation of the piezoelectric resonant pressure sensor 100.

In the use of the piezoelectric resonant pressure sensor 100, only the cover 160 may be provided, only the protective layer 150 may be provided, both the cover 160 and the protective layer 150 may be provided, or neither the cover 160 nor the protective layer 150 may be provided, which is not particularly limited by the present embodiment.

In 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, and thus the detection result of the piezoelectric resonant pressure sensor 100 may be affected. The environmental factors may be temperature, vibration, shock, etc. Based on this, the piezoelectric resonant pressure sensor 100 needs to be compensated.

For example, the present disclosure provides a compensation system 200, and fig. 18 is a schematic structural diagram of the compensation system 200 provided by the present disclosure, referring to fig. 18, the compensation system 200 may include a driving component 230, a detecting component 240, and at least two piezoelectric resonant pressure sensors 100 according to the above embodiments, where the at least two piezoelectric resonant pressure sensors 100 include at least one pressure sensor 210 and at least one compensation sensor 220.

In the case where the pressure sensor 210 is provided in one, the compensation sensor 220 may be provided in only one, or the compensation sensor 220 may be provided in plurality.

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

The number of the compensation sensors 220 and the number of the detection sensors may be equal to each other, and the number of the compensation sensors 220 may be different from the number of the detection sensors.

The pressure sensor 210 is used for detecting the pressure to be detected, and the compensation sensor 220 is used for compensating the influence of environmental factors on the pressure sensor 210. The driving part 230 is connected to the driving electrode of the pressure sensor 210 and to the driving electrode of the compensation sensor 220, and the driving part 230 is used to drive the detection sensor and the compensation sensor 220 to vibrate. The detecting part 240 is connected to the detecting electrode of the pressure sensor 210 and to the detecting electrode of the compensation sensor 220. The detecting unit 240 is used for detecting the resonant frequencies of the pressure sensor 210 and the compensation sensor 220.

Since the pressure sensor 210 and the compensation sensor 220 are integrated together, environmental factors such as temperature, vibration, shock, etc. having the same resonant film 121 may have the same influence on the resonant film 121 of the pressure sensor 210 and the compensation sensor 220, so that the resonant films 121 of the pressure sensor 210 and the compensation sensor 220 may have the same output based on the influence of the environmental factors.

Based on this, when the detecting unit 240 detects the resonant frequencies of the pressure sensor 210 and the compensation sensor 220, the resonant frequency output by the compensation sensor 220 is subtracted from the resonant frequency output by the pressure sensor 210, and the final resonant frequency is extracted, so that the influence of environmental factors can be eliminated, and the accuracy of detecting the pressure to be detected by the compensation system 200 can be improved.

Fig. 19 is a schematic diagram of the workflow of a compensation system 200 provided by the present application, and referring to fig. 19, the workflow of the compensation sensor 220 is specifically as follows:

s101, the driving part 230 is used to drive the pressure sensor 210 and the compensation sensor 220.

S102, the detecting unit 240 is configured 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.

And S103, a calculation module is used for calculating the difference value between the first resonant frequency and the second resonant frequency to obtain the target resonant frequency.

And S104, the calculation module can also calculate a pressure value of the pressure to be detected based on the resonance frequency.

The calculation module may be part of the detecting unit 240, or may be a module independent of the detecting unit 240, which is not limited by the present example.

Based on the compensation system 200 mentioned in the above example, during operation of the compensation system 200, the pressure to be detected can act on the pressure chamber 132 of the pressure sensor, and the pressure to be detected does not act on the compensation sensor 220. Based on this, the structure of the pressure sensor 210 and the structure of the compensation sensor 220 may be completely identical. The structures of the pressure sensor 210 and the compensation sensor 220 may also be inconsistent, for example, the compensation sensor 220 may not be provided with the pressure resonance assembly 130. The specific structures of the pressure sensor 210 and the compensation sensor 220 are not limited by the present example.

In summary, according to the compensation system 200 provided in the present embodiment, when the detecting component 240 detects the resonant frequencies of the pressure sensor 210 and the compensation sensor 220, the resonant frequency output by the compensation sensor 220 is subtracted from the resonant frequency output by the pressure sensor 210, and then the final resonant frequency is extracted, so that the influence of environmental factors can be eliminated, and the accuracy of detecting the pressure to be detected by the compensation system 200 is improved.

It should be noted that the above embodiments are merely specific embodiments of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions within the technical scope of the present application should be covered by the scope of the present application. Therefore, the protection scope of the application is subject to the protection scope of the claims.

Claims

1. A piezoelectric resonant pressure sensor for use in the electronics core industry, comprising:

the piezoelectric component is directly or indirectly connected with the external circuit;

The resonance film is arranged on one side of the piezoelectric component and is directly or indirectly connected with the piezoelectric component;

The pressure resonance component is arranged on one side of the resonance film and is connected with the resonance film, a resonance groove is formed in one side, facing the resonance film, of the pressure resonance component, the resonance film is arranged on an opening of the resonance groove, the resonance groove is matched with the resonance film to form a resonance cavity, a pressure cavity is formed in one side, facing away from the resonance film, of the pressure resonance component, a pressure sensitive film is arranged between the resonance groove and the pressure cavity, and the pressure cavity is used for receiving pressure to be detected;

And the projection of the resonant cavity at least partially falls into the projection range of the pressure cavity along the direction from the resonant film to the pressure resonant assembly.

2. The piezoelectric resonant pressure sensor of claim 1, wherein the junction between the resonant thin film and the pressure resonant assembly is provided with at least a partial oxide layer.

3. The piezoelectric resonant pressure sensor of claim 2, wherein the resonant film is bonded to the pressure resonant assembly, and wherein the bonded connection of the resonant film to the pressure resonant assembly forms at least a portion of the oxide layer.

4. A piezoelectric resonator pressure sensor according to claim 2 or 3, characterized in that the resonator film is processed from an SOI wafer, the pressure resonator assembly is processed from a Si wafer, the device layer of the SOI wafer is bonded to the Si wafer, and at least part of the oxide layer is formed at the bonding position of the SOI wafer and the Si wafer.

5. The piezoelectric resonant pressure sensor of claim 1, wherein a projection of the resonant cavity falls within a projection range of the pressure cavity along a direction of the resonant film to the pressure resonant assembly.

6. The piezoelectric resonant pressure sensor of claim 1, wherein the pressure resonant assembly comprises at least one connection structure disposed on a side of the pressure resonant assembly facing the pressure sensitive membrane, the at least one connection structure cooperating with the pressure sensitive membrane to form the resonant recess.

7. The piezoelectric resonant pressure sensor of claim 6, wherein said pressure resonant assembly further comprises at least one resonant substrate disposed on a side of said pressure resonant assembly facing away from said resonant membrane, at least one of said resonant substrates cooperating with said pressure sensitive membrane to form said pressure chamber.

8. The piezoelectric resonant pressure sensor of claim 1, further comprising a cover disposed on a side of the piezoelectric assembly facing away from the pressure resonant assembly, the cover being directly or indirectly coupled to the piezoelectric assembly.

9. The resonant pressure sensor of claim 1, further comprising a protective layer disposed on a side of the piezoelectric assembly facing away from the resonant assembly.

10. A compensation system, comprising a driving component, a detecting component and at least two piezoelectric resonant pressure sensors according to any one of claims 1-9, wherein at least two piezoelectric resonant pressure sensors comprise at least one pressure sensor and at least one compensation sensor.