Piezoelectric resonant pressure sensor

Abstract

The utility model provides a piezoelectric resonant pressure sensor, relates to the technical field of sensors, and aims to simplify the structure of the piezoelectric resonant pressure sensor and reduce the size of the piezoelectric resonant pressure sensor. The piezoelectric resonant pressure sensor comprises a pressure sensitive assembly and a piezoelectric assembly, and the pressure sensitive assembly is provided with a first surface and a second surface which are oppositely arranged. The pressure sensitive assembly is provided with a pressure cavity penetrating through the second surface, and to-be-detected pressure acts on the cavity wall, close to the first surface, of the pressure cavity. The piezoelectric assembly is arranged on the first surface and is electrically connected with an external circuit through the silicon through hole. The periphery of the piezoelectric assembly is supported on the first surface, and the middle area of the piezoelectric assembly is suspended on the first surface, so that a resonant cavity is formed between the middle area and the first surface. The orthographic projection of the resonant cavity on the second surface is at least partially overlapped with the orthographic projection of the pressure cavity on the second surface.

Description

Technical Field

[0001] The present application relates to the field of sensor technology, and in particular to a piezoelectric resonant pressure sensor. Background Art

[0002] 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 are widely used in applications with high precision requirements and harsh environments, such as aerospace and petroleum, due to their advantages such as good stability and high accuracy.

[0003] The anchor point of the piezoelectric resonant pressure sensor can transfer the stress of the pressure-sensitive film to the resonator, ensuring that the piezoelectric resonant pressure sensor remains stable during operation and improving the accuracy of pressure detection.

[0004] Existing piezoelectric resonant pressure sensors generally use a support structure as an anchor point, which makes the structure of the piezoelectric resonant pressure sensor relatively complex and the size of the piezoelectric resonant pressure sensor relatively large. Utility Model Content

[0005] The present application provides a piezoelectric resonant pressure sensor, which is used to simplify the structure of the piezoelectric resonant pressure sensor and reduce the size of the piezoelectric resonant pressure sensor.

[0006] The present application provides an example of a piezoelectric resonant pressure sensor, comprising a pressure-sensitive component and a piezoelectric component, wherein the pressure-sensitive component has a first surface and a second surface arranged relative to each other. The pressure-sensitive component has a pressure cavity extending through the second surface, and the pressure to be detected acts on the cavity wall of the pressure cavity close to the first surface. The piezoelectric component is arranged on the first surface, and the piezoelectric component is electrically connected to an external circuit via a through-silicon via. The piezoelectric component is supported on the first surface on all sides, and the middle area of the piezoelectric component is suspended on the first surface to form a resonant cavity between the middle area and the first surface. The orthographic projection of the resonant cavity on the second surface at least partially overlaps with the orthographic projection of the pressure cavity on the second surface.

[0007] When the above technical solution is adopted, the middle area of the piezoelectric component forms a resonator, and the side cavity wall of the resonant cavity forms an anchor point. There is no need to set up an additional support structure as an anchor point between the piezoelectric component and the pressure-sensitive component. This can simplify the structure of the piezoelectric resonant pressure sensor and reduce the size of the piezoelectric resonant pressure sensor.

[0008] A pressure-sensitive film is formed between the cavity wall of the pressure cavity close to the first surface and the first surface. The pressure-sensitive film can withstand a large load. When a large pressure to be detected acts on the pressure-sensitive film, the pressure-sensitive film will not undergo a large deformation, thereby improving the pressure-bearing capacity of the pressure-sensitive film, expanding the range of pressures that can be detected by the piezoelectric resonant pressure sensor provided in the embodiment of the present application, improving the scope of application of the piezoelectric resonant pressure sensor provided in the embodiment of the present application, and ensuring the linearity of the piezoelectric resonant pressure sensor within the pressure measurement range.

[0009] In some possible implementations, the piezoelectric component includes a first conductive layer, a piezoelectric layer, and a second conductive layer. The first conductive layer and the second conductive layer are electrically connected to an external circuit via a through-silicon via (TSV). The first conductive layer and the second conductive layer have different polarities. At least in the middle region, the first conductive layer, the piezoelectric layer, and the second conductive layer are stacked in sequence from the pressure-sensitive component to the piezoelectric component. Furthermore, in the middle region, the first conductive layer, the piezoelectric layer, and the second conductive layer protrude away from the pressure-sensitive component to form a resonant cavity.

[0010] In some possible implementations, at least two through silicon vias are provided on the pressure sensitive component, the first conductive layer is electrically connected to the external circuit through at least one of the through silicon vias, and the second conductive layer is electrically connected to the external circuit through at least another through silicon via.

[0011] In some possible implementations, the piezoelectric resonant pressure sensor further includes a cover disposed on the first surface; a cover space is provided on a side of the cover facing the first surface, and the piezoelectric component is located in the cover space.

[0012] When using this technical solution, on the one hand, the piezoelectric component is located within the cover space, and the cover can protect the piezoelectric component and ensure a stable working environment for the piezoelectric component, thereby preventing damage to the piezoelectric component and preventing it from affecting the detection accuracy of the pressure to be detected. On the other hand, it can prevent impurities such as dust and particles from falling on the piezoelectric component and affecting the detection accuracy of the pressure to be detected.

[0013] In some possible implementations, at least two through silicon vias are provided on the cover, the first conductive layer is electrically connected to the external circuit through at least one of the through silicon vias, and the second conductive layer is electrically connected to the external circuit through at least another through silicon via.

[0014] When the above technical solution is adopted, the TSV can be set on the pressure sensitive component or on the cover, which enriches the setting positions of the TSV and facilitates selection according to actual conditions.

[0015] In some possible implementations, the cover is in vacuum connection with the first surface;

[0016] The piezoelectric resonant pressure sensor further comprises an air absorber which is arranged in the cover space. The air absorber is used for absorbing gas after the cover is vacuum-connected to the pressure sensitive component.

[0017] When adopting the above technical solution, the air getter is used to absorb the gas molecules released by the piezoelectric component, pressure sensitive component and other devices after the cover and the pressure sensitive component are sealed and connected, so that the inside of the piezoelectric resonant pressure sensor is maintained in a vacuum state to ensure the vacuum degree of the vacuum cavity, ensure the measurement accuracy and sensitivity of the piezoelectric resonant pressure sensor, and extend the service life of the piezoelectric resonant pressure sensor.

[0018] In some possible implementations, a first bonding ring is provided on the first surface, and the first bonding ring corresponds to the four edges of the pressure-sensitive component; a second bonding ring is provided on the side of the cover close to the first surface, and the first bonding ring and the second bonding ring are bonded to connect the cover to the first surface.

[0019] In some possible implementations, a through groove is provided on the piezoelectric component, the through groove passes through the middle region and is connected to the resonant cavity.

[0020] In some possible implementations, the piezoelectric resonant pressure sensor further includes a lead electrode disposed on a side of the through-silicon via away from the piezoelectric component, and the lead electrode is electrically connected to the through-silicon via.

[0021] In some possible implementations, the piezoelectric component also includes a connecting lead and a connecting lead, and the connecting lead is arranged on the first surface and the piezoelectric layer; one end of the connecting lead is electrically connected to the first conductive layer, and the other end of the connecting lead passes through the piezoelectric layer and is electrically connected to one end of the connecting lead, and the other end of the connecting lead is electrically connected to the silicon through-hole corresponding to the first conductive layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic top view of a piezoelectric resonant pressure sensor provided in an embodiment of the present application Figure 1 .

[0023] Figure 2 for Figure 1 Schematic diagram of the cross section at AA in the middle.

[0024] Figure 3 A schematic diagram of a piezoelectric resonant pressure sensor provided in an embodiment of the present application Figure 1 .

[0025] Figure 4 A schematic diagram of a piezoelectric resonant pressure sensor provided in an embodiment of the present application Figure 2 .

[0026] Figure 5A schematic diagram of a piezoelectric resonant pressure sensor provided in an embodiment of the present application Figure 3 .

[0027] Figure 6 A schematic top view of a piezoelectric resonant pressure sensor provided in an embodiment of the present application Figure 2 .

[0028] Figure 7 A schematic top view of a piezoelectric resonant pressure sensor provided in an embodiment of the present application Figure 3 .

[0029] Figure 8 A schematic top view of a piezoelectric resonant pressure sensor provided in an embodiment of the present application Figure 4 .

[0030] Figure 9 A bottom-up schematic diagram of a piezoelectric resonant pressure sensor provided in an embodiment of the present application.

[0031] Figure 10 A schematic diagram of the positional relationship between a piezoelectric resonant pressure sensor and the pressure to be detected provided in an embodiment of the present application.

[0032] Figure 11 Taking a piezoelectric resonant pressure sensor provided in an embodiment of the present application as an example, a schematic diagram of disassembling and analyzing the pressure to be detected by the piezoelectric resonant pressure sensor provided in an embodiment of the present application Figure 1 .

[0033] Figure 12 Taking a piezoelectric resonant pressure sensor provided in an embodiment of the present application as an example, a schematic diagram of disassembling and analyzing the pressure to be detected by the piezoelectric resonant pressure sensor provided in an embodiment of the present application Figure 2 .

[0034] Figure 13 A diagram showing the steps of a method for preparing a piezoelectric resonant pressure sensor provided in an embodiment of the present application.

[0035] Figures 14 to 34 In order to adopt the preparation method of the piezoelectric resonant pressure sensor provided in the embodiment of the present application, the following is prepared: Figure 3 The structural schematic diagram of the piezoelectric resonant pressure sensor process is shown.

[0036] Figures 35 to 55 In order to adopt the preparation method of the piezoelectric resonant pressure sensor provided in the embodiment of the present application, the following is prepared: Figure 5 The structural schematic diagram of the piezoelectric resonant pressure sensor process is shown.

[0037] Description of reference numerals:

[0038] 10-pressure sensitive component, 10'-first wafer, 11-pressure chamber, 12-silicon structure layer, 13-buried oxide layer, 14-substrate layer,

[0039] 15'-front third conductive layer, 15-first bonding ring;

[0040] 20-piezoelectric component, 21-first conductive layer, 21'-front first conductive layer, 211-connecting lead, 211'-connecting hole, 22-piezoelectric layer,

[0041] 22 ′-front piezoelectric layer, 23-second conductive layer, 23 ′-front second conductive layer, 24-resonant cavity, 25-through slot, 26-connecting lead;

[0042] 30 - cover, 30' - second wafer, 31 - cover space, 32 - second bonding ring, 32' - front fourth conductive layer,

[0043] 40'-front lead electrode layer, 40-lead electrode;

[0044] 50-air-intake piece;

[0045] 60-Through Silicon Via;

[0046] 70-sacrificial layer, 70'-front sacrificial layer. DETAILED DESCRIPTION

[0047] To make the purpose, technical solutions, and advantages of the examples of this application more clear, the technical solutions in the examples of this application will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the examples described are only 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 making any creative efforts are within the scope of protection of this application.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs; the terms used herein in the specification of the application are only for the purpose of describing specific examples and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification, claims and drawings of this application are intended to cover non-exclusive inclusions.

[0049] References to "examples" herein mean that a particular feature, structure, or characteristic described in connection with the examples may be included in at least one example of the present application. The appearance of the phrase "example" in various places in the specification does not necessarily refer to the same example, nor does it constitute an independent or alternative example that is mutually exclusive of other examples. It is understood, both explicitly and implicitly, by those skilled in the art that the examples described herein may be combined with other examples.

[0050] The term "and / or" in this document simply describes a relationship between related objects, indicating that three possible relationships exist. For example, "A and / or B" can mean: A exists, A and B exist, and B exists. Additionally, the character " / " in this document generally indicates that the related objects are in an "or" relationship.

[0051] The directional words appearing in the following description refer to the directions shown in the drawings and do not limit the specific structure of the piezoelectric resonant pressure sensor of the present application.

[0052] In addition, the terms "first", "second", etc. in the description 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 such features.

[0053] In the description of this application, unless otherwise specified, "plurality" means more than two (including two), and similarly, "multiple groups" means more than two (including two).

[0054] In the description of this 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 connection or snap connection; the physical connection may also be an integral connection, such as a connection formed by welding, bonding, or integral molding. For those skilled in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0055] Resonant pressure sensors indirectly measure the pressure to be detected by measuring the change in the resonant frequency of the structure. They have the advantages of high precision and good stability and are suitable for scenarios with high precision requirements and harsh environments, such as aerospace, oil and gas exploration, etc.

[0056] Existing resonant pressure sensors include electrostatic excitation-resistance detection resonant pressure sensors, piezoelectric excitation-piezoelectric detection resonant pressure sensors, electromagnetic drive-electromagnetic detection resonant pressure sensors, optical drive-optical detection resonant pressure sensors, and quartz piezoelectric resonant pressure sensors. The measurement structure can be a detection circuit or other structure capable of detecting the pressure to be measured.

[0057] The anchor point of the piezoelectric resonant pressure sensor can transfer the stress of the pressure-sensitive film to the resonator, ensuring that the piezoelectric resonant pressure sensor remains stable during operation and improving the accuracy of pressure detection.

[0058] Existing piezoelectric resonant pressure sensors generally use a support structure as an anchor point, which makes the structure of the piezoelectric resonant pressure sensor relatively complex and the size of the piezoelectric resonant pressure sensor relatively large.

[0059] In view of the problems existing in the above-mentioned prior art, an embodiment of the present application provides a piezoelectric resonant pressure sensor, which can be combined with MEMS (Micro-Electro-Mechanical Systems) technology to achieve mass production of piezoelectric resonant pressure sensors and improve the production efficiency of piezoelectric resonant pressure sensors.

[0060] In order to enable those skilled in the art to better understand the present application, the piezoelectric resonant pressure sensor and its preparation method provided in the embodiment of the present application will be clearly and completely described below with reference to the accompanying drawings.

[0061] See also Figures 1 to 5 As shown, the piezoelectric resonant pressure sensor provided in the embodiment of the present application includes a pressure sensitive component 10 and a piezoelectric component 20 .

[0062] The pressure-sensitive component 10 has a first surface and a second surface disposed opposite each other, and the piezoelectric component 20 is disposed on the first surface. The pressure-sensitive component 10 has a pressure chamber 11 extending through the second surface, such that the pressure chamber 11 is a cavity with an opening, and the opening end of the pressure chamber 11 is located on the second surface, so that the pressure to be detected can enter the pressure chamber 11 and act on the cavity wall of the pressure chamber 11 near the first surface to detect the pressure to be detected.

[0063] It should be noted that a pressure-sensitive film is formed between the cavity wall of the pressure cavity 11 close to the first surface and the first surface. After the pressure to be detected enters the pressure cavity 11 , it acts on the pressure-sensitive film.

[0064] The pressure-sensitive film can withstand a large load. When a large pressure to be detected acts on the pressure-sensitive film, the pressure-sensitive film will not undergo large deformation, which improves the pressure-bearing capacity of the pressure-sensitive film, expands the range of pressures that can be detected by the piezoelectric resonant pressure sensor provided in the embodiment of the present application, improves the scope of application of the piezoelectric resonant pressure sensor provided in the embodiment of the present application, and ensures the linearity of the piezoelectric resonant pressure sensor within the pressure measurement range.

[0065] In a specific implementation, the pressure sensitive component 10 can be made of an SOI wafer. The structure of the pressure sensitive component 10 can be a cylindrical structure, a rectangular parallelepiped structure, a prismatic structure, etc., which is not specifically limited here.

[0066] When the pressure sensitive component 10 is processed from an SOI wafer, the pressure sensitive component 10 further includes a silicon structure layer 12, a buried oxide layer 13 and a substrate layer 14, such as Figures 2 to 5 As shown in FIG. The silicon structure layer 12, the buried oxide layer 13, and the substrate layer 14 are stacked sequentially along the direction from the first surface to the second surface. The buried oxide layer 13 is an oxide layer formed during the bonding process when the silicon structure layer 12 and the substrate layer 14 are bonded together. This layer can be used to precisely control the thickness of the silicon structure layer 12.

[0067] In this case, in the embodiment provided in this application, the side of the silicon structure layer 12 away from the buried oxide layer 13 forms the first surface of the pressure sensitive component 10, and the side of the substrate layer 14 away from the buried oxide layer 13 forms the second surface of the pressure sensitive component 10.

[0068] In this manner, the pressure chamber 11 is formed on the substrate layer 14. Specifically, the pressure chamber 11 can penetrate the substrate layer 14 from the first surface to the second surface. This allows the cavity wall of the pressure chamber 11, which is close to the first surface, to be coplanar with the surface of the buried oxide layer 13, which is close to the substrate layer 14. Consequently, at the location corresponding to the pressure chamber 11, a pressure-sensitive film is formed between the surface of the buried oxide layer 13, which is close to the substrate layer 14, and the first surface.

[0069] It can be further shown that the pressure chamber 11 is a space formed by the side of the buried oxide layer 13 close to the substrate layer 14 and the substrate layer 14 .

[0070] In addition, in the embodiments provided in the present application, the shape of the pressure chamber 11 may be cylindrical, the shape of the pressure chamber 11 may be prismatic, or the shape of the pressure chamber 11 may be irregular. Of course, the present invention is not limited thereto.

[0071] The central axis of the pressure chamber 11 may coincide with the central axis of the pressure sensitive component 10 , or they may be staggered.

[0072] The method for forming the pressure chamber 11 on the substrate layer 14 is not specifically limited herein. As an example, dry etching or wet etching can be used to etch the side of the substrate layer 14 away from the buried oxide layer 13 to form the pressure chamber 11. In the embodiments provided herein, dry etching is preferred.

[0073] The number of the pressure chambers 11 is not specifically limited herein. For example, the number of the pressure chamber 11 may be one, and of course, a plurality of pressure chambers 11 may also be provided at intervals.

[0074] In actual situations, the pressure sensitive component 10 may also include only a pressure sensitive film. In this case, the pressure chamber 11 may be a space where the pressure sensitive film is away from the piezoelectric component 20. This is merely an example and is not intended to be a specific limitation.

[0075] The pressure to be detected that enters the pressure chamber 11 and acts on the cavity wall of the pressure chamber 11 near the first surface can be the pressure directly or indirectly applied to the pressure sensitive component 10 by a fluid, such as a liquid or gas. Of course, the pressure to be detected can also be the pressure applied to the pressure sensitive component 10 by an external mechanical structure in direct contact with the cavity wall of the pressure chamber 11 near the first surface.

[0076] When the pressure sensitive component 10 is made of an SOI wafer, the piezoelectric component 20 is disposed on the first surface. Specifically, the piezoelectric component 20 is disposed on the silicon structure layer 12. The silicon structure layer 12 serves as a support layer and can provide a stable supporting force for the piezoelectric component 20.

[0077] In the embodiment provided in this application, the piezoelectric component 20 can be formed on the first surface by a deposition process.

[0078] As an example, the piezoelectric component 20 is electrically connected to an external circuit via a through-silicon via 60. Through-silicon via technology significantly improves the integration of piezoelectric resonant pressure sensors and reduces their size and weight by drilling holes in the device and filling them with conductive materials such as copper, tungsten, and polysilicon.

[0079] In a specific implementation, the through silicon via 60 can be opened on the pressure sensitive component 10, such as Figure 2 shown.

[0080] See also Figures 2 to 5 As shown, the periphery of the piezoelectric assembly 20 is supported on the first surface, and the middle region of the piezoelectric assembly 20 is suspended above the first surface, so as to form a resonant cavity 24 between the middle region and the first surface. A gap is provided between the middle region of the piezoelectric assembly 20 and the first surface, and this gap is the resonant cavity 24 described in the embodiments of the present application.

[0081] In this way, the central region of the piezoelectric assembly 20 forms the resonator of the piezoelectric resonant pressure sensor provided in the embodiment of the present application. The portion of the piezoelectric assembly 20 that encloses the sidewalls of the resonant cavity 24 forms the anchor point of the piezoelectric resonant pressure sensor provided in the embodiment of the present application. One end of the anchor point is supported on the first surface of the pressure-sensitive assembly 10, and the other end of the anchor point is connected to the resonator. The anchor point serves as a bridge between the pressure-sensitive assembly 10 and the resonator, supporting the resonator in mid-air above the pressure-sensitive assembly 10. The anchor point connects the pressure-sensitive assembly 10 and supports the resonator.

[0082] Furthermore, the orthographic projection of the resonant cavity 24 on the second surface at least partially overlaps with the orthographic projection of the pressure cavity 11 on the second surface. In other words, the orthographic projection of the resonant cavity 24 on the second surface at least partially falls within the orthographic projection of the pressure cavity 11 on the second surface. This ensures that the pressure-sensitive film can bend toward the piezoelectric assembly 20 when subjected to the pressure to be detected. In other words, the resonant cavity 24 provides deformation space for the pressure-sensitive film.

[0083] At the same time, since the side cavity wall of the resonant cavity 24 forms an anchor point, when the orthographic projection of the resonant cavity 24 on the second surface at least partially overlaps with the orthographic projection of the pressure cavity 11 on the second surface, the pressure-sensitive film partially overlaps with the resonant cavity 24, which can ensure that the anchor point is in contact with the pressure-sensitive film, and further ensure that the anchor point transfers the stress generated by the pressure to be detected on the pressure-sensitive film to the resonator, so that the resonator is subjected to stress and the vibration frequency of the resonator is changed.

[0084] For example, the orthographic projection of the resonant cavity 24 on the second surface may completely fall within the orthographic projection of the pressure chamber 11 on the second surface. In this case, the geometric center of the orthographic projection of the resonant cavity 24 on the second surface may overlap with the geometric center of the orthographic projection of the pressure chamber 11 on the second surface. In this case, the orthographic projections of the geometric centers of the resonant cavity 24, the pressure chamber 11, the pressure sensitive component 10, and the piezoelectric component 20 on the second surface may all coincide, or may not coincide or may partially coincide.

[0085] The orthographic projection of the resonance cavity 24 on the second surface may partially fall within the orthographic projection range of the pressure cavity 11 on the second surface. In other words, the orthographic projection of the resonance cavity 24 on the second surface partially overlaps with the orthographic projection of the pressure cavity 11 on the second surface.

[0086] The embodiment of the present application does not impose any specific limitation on the positional relationship between the resonance cavity 24 and the pressure cavity 11. It is only necessary to ensure that the orthographic projection of at least part of the resonance cavity 24 on the second surface coincides with the orthographic projection of the pressure cavity 11 on the second surface, thereby ensuring that the pressure to be detected entering the pressure cavity 11 can be transmitted to the resonator through the anchor point and converted into stress on the resonator, thereby causing a change in the vibration frequency of the resonator, and then detecting the pressure to be detected through the change in the vibration frequency of the resonator.

[0087] In specific implementation, the shape of the resonance cavity 24 may be the same as that of the pressure cavity 11 , or may be different. This is not specifically limited here, and the actual situation shall prevail.

[0088] The number of the resonant cavities 24 can be set to one or more, and this example of the application does not limit this.

[0089] In the embodiments provided in this application, the formation method of the resonant cavity 24 is not specifically limited here.

[0090] For example, a groove may be directly formed on the side of the piezoelectric component 20 close to the pressure sensitive component 10. When the piezoelectric component 20 is disposed on the first surface, a resonant cavity 24 is formed between the groove wall and the first surface.

[0091] Alternatively, before forming the piezoelectric component 20 on the pressure-sensitive component 10 through a deposition process, a sacrificial layer may be formed on the pressure-sensitive component 10. After the piezoelectric component 20 is formed, the sacrificial layer is released and removed, and the space occupied by the sacrificial layer becomes the resonant cavity 24. Furthermore, after the sacrificial layer is released and removed, the portion of the piezoelectric component 20 that encloses the sidewalls of the resonant cavity 24 forms an anchor point.

[0092] It should be noted that, in actual situations, the external circuit includes a detection circuit and a drive circuit. The detection circuit can be a circuit for detecting the magnitude of current, a circuit for detecting the magnitude of voltage, or a circuit for detecting the amount of charge. The embodiments of the present application do not limit the specific type of the detection circuit, as long as the external circuit can detect the electrical signal output by the piezoelectric component 20. The drive circuit is a circuit that drives the resonator of the piezoelectric component 20 to vibrate.

[0093] When using the above-mentioned piezoelectric resonant pressure sensor, the resonator has a certain resonant frequency. When the piezoelectric component 20 is connected to the driving circuit, when the frequency of the electrical signal applied to the resonator by the driving circuit is consistent with the resonant frequency, the resonant frequency of the resonator is reached, and the vibration frequency of the resonator is maximized. When the pressure to be detected enters the pressure chamber 11 from the open end of the pressure chamber 11 and acts on the cavity wall of the pressure chamber 11 close to the first surface, the pressure-sensitive film is deformed by the pressure to be detected and bends in the direction close to the piezoelectric component 20. The pressure-sensitive film can transfer deformation and stress to the anchor point. Further, the anchor point transfers pressure and deformation to the resonator, causing the vibration frequency of the resonator to change. The detection circuit obtains data such as the magnitude and direction of the pressure to be detected by receiving and analyzing the changes in the vibration frequency of the resonator.

[0094] At the same time, the anchor point can isolate the pressure to be detected from the resonator, preventing the pressure to be detected from directly acting on the resonator, improving the pressure-bearing capacity of the piezoelectric resonant pressure sensor provided in the embodiment of the present application, and increasing the range of pressure to be detected that the piezoelectric resonant pressure sensor can measure.

[0095] The setting of the resonant cavity 24 can provide a vibration space for the resonator, reduce the possibility of the resonator causing a large deformation due to vibration, and thus causing damage to the piezoelectric component 20, increase the range of pressure to be detected that can be measured by the piezoelectric resonant pressure sensor, expand the measurement range of the piezoelectric resonant pressure sensor, and expand the scope of application of the piezoelectric resonant pressure sensor.

[0096] Furthermore, in the embodiment provided herein, the side walls of the resonant cavity 24 form anchor points, eliminating the need for additional support structures between the piezoelectric component 20 and the pressure-sensitive component 10. This simplifies the structure of the piezoelectric resonant pressure sensor and reduces its size. This addresses the problem of existing piezoelectric resonant pressure sensors, which suffer from complex structures and large sizes that preclude miniaturization.

[0097] The pressure-sensitive film provided in the embodiment of the present application can withstand a large load. When a large pressure to be detected acts on the pressure-sensitive film, the pressure-sensitive film will not undergo a large deformation, thereby improving the pressure-bearing capacity of the pressure-sensitive film, expanding the range of pressures to be detected that can be detected by the piezoelectric resonant pressure sensor provided in the embodiment of the present application, improving the scope of application of the piezoelectric resonant pressure sensor provided in the embodiment of the present application, and ensuring the linearity of the piezoelectric resonant pressure sensor within the pressure measurement range.

[0098] In some possible implementations, see Figures 2 to 5 As shown, the piezoelectric component 20 includes a first conductive layer 21 , a piezoelectric layer 22 and a second conductive layer 23 . The first conductive layer 21 and the second conductive layer 23 are electrically connected to an external circuit through a through silicon via 60 .

[0099] The first conductive layer 21 and the second conductive layer 23 have different polarities. The first conductive layer 21 can be electrically connected to an external circuit, and the second conductive layer 23 can be grounded. Of course, it can also be set that the first conductive layer 21 is grounded and the second conductive layer 23 is electrically connected to an external circuit to achieve electrical connection among the first conductive layer 21, the piezoelectric layer 22, and the second conductive layer 23.

[0100] In a specific implementation, the piezoelectric layer 22 is the main functional layer of the piezoelectric component 20 , and can realize the positive piezoelectric effect and the inverse piezoelectric effect in conjunction with the first conductive layer 21 and the second conductive layer 23 , thereby realizing the sensing of the pressure to be detected.

[0101] The piezoelectric layer 22 is a piezoelectric thin film material. Specific materials for the piezoelectric layer 22 may include AlN (aluminum nitride), ScAlN (scandium-doped aluminum nitride), PZT (lead zirconate titanate), ZnO (zinc oxide), LiNbO3 (lithium niobate), etc. The material of the piezoelectric layer 22 is preferably AlN or ScAlN.

[0102] Due to the piezoelectricity of the piezoelectric film material, when the piezoelectric layer 22 receives pressure, an electric potential difference can be generated on the two opposite sides of the piezoelectric layer 22. By utilizing the positive piezoelectric effect and the inverse piezoelectric effect of the piezoelectric layer 22, the relevant parameters of the pressure to be detected can be obtained. The relevant parameters may include the numerical size of the pressure to be detected and the direction parameters of the pressure to be detected.

[0103] The first conductive layer 21 and the second conductive layer 23 can both be used as driving electrodes for driving the resonator to vibrate. In the embodiment provided in this application, the second conductive layer 23 is used as the driving electrode for example.

[0104] When the second conductive layer 23 is a driving electrode, after the second conductive layer 23 is electrically connected to the external circuit, the second conductive layer 23 can drive the piezoelectric layer 22, using the inverse piezoelectric effect of the piezoelectric layer 22 to cause the resonator to vibrate, and at the same time use the direct piezoelectric effect of the piezoelectric layer 22 to detect the vibration of the resonator.

[0105] In a specific implementation, the second conductive layer 23 may include a top electrode, such as Figure 6 The second conductive layer 23 may also include two top electrodes, such as Figure 1 、 Figure 7 and Figure 8 Of course, the second conductive layer 23 may also include three, four or more top electrodes, which is not specifically limited here.

[0106] It is worth noting that Figure 6 As shown in Figure 1, the top electrode is in the shape of a cross. Figure 1 As shown in the figure, the top electrode is in a right angle shape, and the two top electrodes are placed together in a cross shape. Figure 7 As shown, the top electrode is in a straight line shape, and the two top electrodes are arranged opposite to each other. Figure 8 As shown, the top electrode is in a tuning fork-shaped structure, and the two top electrodes are arranged opposite to each other. The shape and combination of the top electrodes are not limited to this, and the specific embodiment shall prevail.

[0107] When the second conductive layer 23 includes a top electrode, the top electrode serves as a driving electrode and a detecting electrode at the same time.

[0108] Specifically, when the top electrode is electrically connected to the driving circuit, it can drive the resonator to vibrate, and the top electrode acts as a driving electrode. When the top electrode is electrically connected to the detection circuit, it can output the vibration signal of the resonator to obtain data of the pressure to be detected. In this case, the top electrode acts as a detection electrode.

[0109] During specific operation, the top electrode may be alternately electrically connected to the drive circuit and the detection circuit. For example, the top electrode may be alternately electrically connected to the drive circuit within the first 0.5 second, electrically connected to the detection circuit within the second 0.5 second, electrically connected to the drive circuit within the third 0.5 second, and electrically connected to the detection circuit within the fourth 0.5 second, and the electrical connections between the top electrode and the drive circuit and the detection circuit may be alternately arranged.

[0110] When the second conductive layer 23 includes two top electrodes, one top electrode may be set as a driving electrode electrically connected to the driving circuit, and the other top electrode may be set as a detecting electrode electrically connected to the detecting circuit.

[0111] When the second conductive layer 23 includes more top electrodes, some of the top electrodes may be configured as driving electrodes electrically connected to the driving circuit, and other top electrodes may be configured as detecting electrodes electrically connected to the detecting circuit.

[0112] The first conductive layer 21 and the second conductive layer 23 are both made of conductive metals. For example, the first conductive layer 21 and the second conductive layer 23 can be made of Mo, Au, Pt, Al, etc., preferably Mo.

[0113] See also Figure 2 and Figure 3 As shown, at least in the middle region, the first conductive layer 21, the piezoelectric layer 22, and the second conductive layer 23 are stacked in sequence from the pressure sensitive component 10 to the piezoelectric component 20. Furthermore, in the middle region, the first conductive layer 21, the piezoelectric layer 22, and the second conductive layer 23 protrude away from the pressure sensitive component 10 to form a resonant cavity 24.

[0114] The thickness of the first conductive layer 21 is uniform, the thickness of the piezoelectric layer 22 is uniform, and the thickness of the second conductive layer 23 is uniform.

[0115] In this case, a deposition process can be used to form the piezoelectric component 20. Specifically, a sacrificial layer is first deposited on the first surface. Then, a first conductive layer 21, a piezoelectric layer 22, and a second conductive layer 23 are sequentially deposited on the sacrificial layer and the first surface. The sacrificial layer is then released to form the piezoelectric component 20 provided in the embodiment of the present application. Compared to traditional mechanical processing methods for processing the piezoelectric component 20, this method can more efficiently utilize raw materials, improve production efficiency and product quality, and at the same time, expand the range of materials that can be used in the piezoelectric component 20.

[0116] It should be noted that the thickness of the first conductive layer 21 refers to the dimension of the first conductive layer 21 from the first surface to the second surface. Similarly, the thickness of the piezoelectric layer 22 refers to the dimension of the piezoelectric layer 22 from the first surface to the second surface. The thickness of the second conductive layer 23 refers to the dimension of the second conductive layer 23 from the first surface to the second surface.

[0117] Based on the above-mentioned piezoelectric resonant pressure sensor, the resonator is a multilayer structure formed by a first conductive layer 21, a piezoelectric layer 22, and a second conductive layer 23. The resonator is supported on the pressure sensitive component 10 by an anchor point. The resonator has a certain resonant frequency. When the frequency of the voltage applied by the driving circuit is consistent with the resonant frequency, the resonator's vibration will reach its maximum, i.e., resonance, due to the inverse piezoelectric effect of the piezoelectric layer 22. At this time, the resonant frequency is:

[0118]

[0119] Where, f r is the resonant frequency, μ n is a constant set when solving the Bessel function, t is the thickness of the resonator, r is the radius of the resonant cavity 24, E is the Young's modulus, ρ is the complex density of the resonator, and δ is the Poisson's ratio.

[0120] It should be noted that when the second conductive layer 23 includes a plurality of top electrodes, a portion of the top electrodes can be set as drive electrodes electrically connected to the drive circuit, and another portion of the top electrodes can be set as detection electrodes electrically connected to the detection circuit. When the drive electrode drives the resonator to vibrate, its vibration will also be detected by the detection electrode. Due to the positive piezoelectric effect of the piezoelectric material, an electrical signal will be generated on the detection electrode, and the electrical signal can be used to detect the resonant frequency of the resonator without the need to arrange an additional detection circuit. However, the pressure sensor in the prior art generally requires the additional setting of a detection circuit. For example, a resistance detection type piezoelectric sensor needs to set a Wheatstone bridge, and a capacitance detection type pressure sensor needs to set a capacitance bridge, etc. The components and circuits are relatively complex, which is not conducive to simplifying the structure of the sensor.

[0121] In an alternative approach, see Figure 2 and Figure 3 As shown, at least two through silicon vias 60 are provided on the pressure sensitive component 10 , the first conductive layer 21 is electrically connected to the external circuit through at least one of the through silicon vias 60 , and the second conductive layer 23 is electrically connected to the external circuit through at least another through silicon via 60 .

[0122] One end of the through silicon via 60 provided on the pressure sensitive component 10 passes through the first surface, and the other end passes through the second surface.

[0123] The number of through-silicon vias 60 can be two, three, four, or more. The number of through-silicon vias 60 used to connect to the second conductive layer 23 can be the same as the number of top electrodes included in the second conductive layer 23, and they correspond one to one. The number of through-silicon vias 60 used to connect to the first conductive layer 21 can be one, two, or more, and is not specifically limited here.

[0124] In addition, if Figure 2and Figure 3 As shown, a plurality of lead electrodes 40 are further provided on the pressure sensitive component 10, and the lead electrodes 40 cooperate with the through-silicon vias 60. The number of lead electrodes 40 is not specifically limited herein, and the number of lead electrodes 40 can be the same as the number of through-silicon vias 60, and the lead electrodes 40 can correspond to the through-silicon vias 60 one-to-one, that is, one lead electrode 40 corresponds to one through-silicon via 60. It should be understood that the number of lead electrodes 40 can also be different from the number of through-silicon vias 60.

[0125] The lead electrodes 40 are electrically connected to the first conductive layer 21 and the second conductive layer 23 through the through silicon vias 60, thereby electrically connecting the first conductive layer 21 and the second conductive layer 23 to an external circuit.

[0126] like Figure 9 As shown, illustratively, there are six lead electrodes 40, of which four are electrically connected to the second conductive layer 23 via corresponding four through-silicon vias 60. At least one lead electrode 40 is connected to a drive electrode for driving the resonator to vibrate via a corresponding through-silicon via 60, and at least one other lead electrode 40 is connected to a detection electrode for detection via a corresponding through-silicon via 60. The other two of the six lead electrodes 40 are electrically connected to the first conductive layer 21 via corresponding two through-silicon vias 60.

[0127] The material of the lead electrode 40 is a conductive metal. For example, the material of the lead electrode 40 can be Al, Au, Pt, etc., preferably Al or Au.

[0128] As a possible implementation, see Figures 3 to 5 As shown, the piezoelectric resonant pressure sensor further includes a cover 30 disposed on the first surface. A cover space 31 is disposed on a side of the cover 30 facing the first surface, and the piezoelectric component 20 is located in the cover space 31.

[0129] The provision of the cover 30, on the one hand, positions the piezoelectric assembly 20 within the cover space 31, thereby protecting the piezoelectric assembly 20 and ensuring a stable operating environment for the piezoelectric assembly 20. This not only prevents damage to the piezoelectric assembly 20 but also prevents the accuracy of the pressure being measured from being affected. Furthermore, this prevents impurities such as dust and particles from settling on the piezoelectric assembly 20 and affecting the accuracy of the pressure being measured.

[0130] In a specific implementation, the cover 30 can be fixedly connected to the pressure sensitive component 10 by bonding, welding, clamping, etc., preferably bonding.

[0131] The material of the cover 30 can be silicon or glass, etc., which is not specifically limited here.

[0132] In the embodiment provided in the present application, the cover 30 is made of a silicon wafer or a glass wafer, and the cover 30 and the pressure sensitive component 10 can be bonded together.

[0133] Specifically, see Figures 1 to 4 As shown, a first bonding ring 15 is provided on the first surface of the pressure sensitive component 10. The first bonding ring 15 corresponds to the four edges of the pressure sensitive component 10. Accordingly, in order to bond the cover 30 to the pressure sensitive component 10, see Figure 3 As shown, a second bonding ring 32 is correspondingly provided on one side of the cover 30 close to the first surface, and the first bonding ring 15 and the second bonding ring 32 match.

[0134] The first bonding ring 15 can be made of Al, and the second bonding ring 32 can be made of Ge. Alternatively, the first bonding ring 15 can be made of Ge, and the second bonding ring 32 can be made of Al, so that the first bonding ring 15 and the second bonding ring 32 are bonded by Ge-Al. Of course, the first bonding ring 15 and the second bonding ring 32 can also be bonded by fusion bonding, Au-Au bonding, or anodic bonding, which is not specifically limited in this application.

[0135] In another optional embodiment, at least two through silicon vias 60 are provided on the cover 30 , wherein at least one through silicon via 60 is electrically connected to the first conductive layer 21 , and at least another through silicon via 60 is electrically connected to the second conductive layer 23 .

[0136] It should be noted that when the piezoelectric resonant pressure sensor provided in the embodiment of the present application includes a cover 30, the through silicon vias 60 can be set on the pressure sensitive component 10, such as Figure 3 As shown. The TSVs 60 can also be arranged on the cover 30, as shown. Figure 4 and Figure 5 shown.

[0137] Of course, during specific implementation, part of the TSVs 60 may be disposed on the pressure sensitive component 10 , and another part of the TSVs 60 may be disposed on the cover 30 .

[0138] See also Figure 4 and Figure 5 As shown, the through silicon vias 60 are all provided on the cover 30. One end of the through silicon via 60 provided on the cover 30 passes through the side of the cover 30 close to the pressure sensitive component 10, and the other end passes through the side of the cover 30 away from the pressure sensitive component 10.

[0139] The first conductive layer 21 is electrically connected to an external circuit through at least one through-silicon via 60 , and the second conductive layer 23 is electrically connected to an external circuit through at least another through-silicon via 60 .

[0140] The number of through-silicon vias 60 provided on the cover 30 may be two, three, four, or more. The number of through-silicon vias 60 used for connecting to the second conductive layer 23 may be the same as the number of top electrodes included in the second conductive layer 23, and the number of through-silicon vias 60 used for connecting to the first conductive layer 21 may be one, two, or more, and is not specifically limited herein.

[0141] Likewise, if Figure 4 and Figure 5 As shown, a plurality of lead electrodes 40 are further provided on the pressure sensitive component 10, and the lead electrodes 40 cooperate with the through-silicon vias 60. The number of lead electrodes 40 is not specifically limited herein, and the number of lead electrodes 40 can be the same as the number of through-silicon vias 60, and the lead electrodes 40 can correspond to the through-silicon vias 60 one-to-one, that is, one lead electrode 40 corresponds to one through-silicon via 60. It should be understood that the number of lead electrodes 40 can be different from the number of through-silicon vias 60.

[0142] The lead electrodes 40 are electrically connected to the first conductive layer 21 and the second conductive layer 23 through the through silicon vias 60, thereby electrically connecting the first conductive layer 21 and the second conductive layer 23 to an external circuit.

[0143] It should be noted that, see Figure 4 As shown, the through-silicon via 60 is provided on the cover 30, and the material of the second conductive layer 23 can be the same as that of the first bonding ring 15. In this case, a connecting hole is provided on the piezoelectric layer 22. When the second conductive layer 23 is deposited on the piezoelectric layer 22 and the first surface using a deposition process, part of the metal fills the connecting hole to form a connecting lead 211. One end of the connecting lead 211 is electrically connected to the first conductive layer 21, and the other end of the connecting lead 211 passes through the piezoelectric layer 22. In addition, at the position corresponding to the connecting hole and the through-silicon via 60 matching the first conductive layer 21, a connecting lead 26 is formed. One end of the connecting lead 26 is electrically connected to the through-silicon via 60 corresponding to the first conductive layer 21, and the other end of the connecting lead 26 is electrically connected to the other end of the connecting lead 211, thereby achieving electrical connection between the first conductive layer 21 and the through-silicon via 60.

[0144] In addition, see Figure 5 As shown, the through-silicon via 60 is provided on the cover 30, and the material of the second conductive layer 23 can be different from that of the first bonding ring 15. In this case, a connecting hole is also provided on the piezoelectric layer 22. When the second conductive layer 23 is deposited on the piezoelectric layer 22 and the first surface using a deposition process, a portion of the metal fills the connecting hole to form a connecting lead 211, which is electrically connected to the first conductive layer 21.

[0145] At the same time, a connection base is provided at a position corresponding to the connection lead 211, and the connection base is electrically connected to the connection lead 211. The material of the connection base, the material of the second conductive layer 23 and the connection lead 211 are the same.

[0146] Afterwards, a third conductive layer is continuously deposited on the second conductive layer 23 and the first surface, and the third conductive layer is etched to form a connecting lead 26 .

[0147] In this example, not only are connecting leads 26 provided at positions corresponding to the connection base and the through silicon via 60 matching the first conductive layer 21, one end of the connecting lead 26 is electrically connected to the through silicon via 60, and the other end of the connecting lead 26 is electrically connected to the connection base, thereby achieving electrical connection between the first conductive layer 21 and the through silicon via 60. Moreover, connecting leads 26 are also provided at positions corresponding to the second conductive layer 23 and the through silicon via 60 matching the second conductive layer 23. Figure 5 As shown, one end of the connecting lead 26 is electrically connected to the through silicon via 60 , and the other end of the connecting lead 26 is electrically connected to the second conductive layer 23 , thereby achieving electrical connection between the second conductive layer 23 and the through silicon via 60 .

[0148] As one possible implementation, the cover 30 is connected to the first surface in a vacuum state. In this case, a vacuum chamber is formed between the cover 30 and the first surface, and the piezoelectric assembly 20 is located within the vacuum chamber. The piezoelectric assembly 20 operates in a vacuum environment, which improves the quality factor of the piezoelectric resonant pressure sensor, ensures its performance, and enhances the measurement accuracy of the detected pressure.

[0149] Further, see Figures 3 to 5 As shown, the piezoelectric resonant pressure sensor provided in the embodiment of the present application further includes an air absorber 50 , which is disposed in the cover space 31 . The air absorber 50 is used to absorb gas after the cover 30 is vacuum-connected to the pressure sensitive component 10 .

[0150] In a specific implementation, the getter 50 may be a thin film getter or other structure capable of maintaining a vacuum inside the piezoelectric resonant pressure sensor.

[0151] Specifically, the suction part 50 is used to absorb the gas molecules released from the piezoelectric component 20, the pressure sensitive component 10 and other devices after the cover 30 and the pressure sensitive component 10 are vacuum connected, so that the inside of the piezoelectric resonant pressure sensor is maintained in a vacuum state, so as to ensure the vacuum degree of the vacuum cavity, ensure the measurement accuracy and sensitivity of the piezoelectric resonant pressure sensor, and extend the service life of the piezoelectric resonant pressure sensor.

[0152] The suction member 50 is mounted on the inner wall of the cover 30. The suction member 50 can be arranged on the cavity wall of the vacuum chamber away from the first surface. Of course, the suction member 50 can also be arranged on the side cavity wall of the vacuum chamber, which is not specifically limited here.

[0153] It should be noted that the cover space 31 between the cover 30 and the pressure sensitive component 10 provided in the embodiment of the present application can maintain a vacuum to form a vacuum cavity. Of course, the cover space 31 can also be filled with a medium.

[0154] When the cover space 31 is a vacuum chamber, the piezoelectric resonant pressure sensor provided in the embodiment of the present application is an absolute pressure sensor. The absolute pressure sensor is used to measure absolute pressure and can convert the pressure to be detected into an equivalent electrical signal output.

[0155] When the cover space 31 is filled with a medium, the cover space 31 has a certain pressure. The piezoelectric resonant pressure sensor provided in the embodiment of the present application is a relative pressure sensor, and the measurement result of the relative pressure sensor is relative to the pressure in the cover space 31.

[0156] Users can select a suitable absolute pressure sensor or relative pressure sensor according to their needs. The example of this application does not limit whether the cover space 31 of the piezoelectric resonant pressure sensor is filled with a medium.

[0157] In some embodiments, see Figures 2 to 5 A through slot 25 is formed on the piezoelectric component 20 . The through slot 25 passes through the middle area and is connected to the resonant cavity 24 .

[0158] The number of the through slots 25 may be one, two, three or more, which is not specifically limited here.

[0159] For ease of understanding, the working principle of the piezoelectric resonant pressure sensor provided in an embodiment of the present application is described below in a possible implementation manner. Of course, this is not a specific limitation here.

[0160] After the second conductive layer 23 is connected to the driving circuit, the resonator vibrates, and the vibration frequency of the resonator is set to the resonant frequency through a phase-locked loop or other technology.

[0161] like Figure 10 As shown, the pressure sensitive component 10 inputs the pressure P to be detected through the pressure chamber 11. The pressure P to be detected acts on the pressure sensitive film, causing the pressure sensitive film to bend and deform in the direction close to the piezoelectric component 20, and transfer the stress to the anchor point.

[0162] Figure 11 and Figure 12The stress analysis of the anchor point is shown. The stress acting on the anchor point is mainly divided into two aspects. First, when the pressure sensitive film is subjected to the pressure P to be detected, the pressure sensitive film bends and deforms in the direction closer to the piezoelectric component 20, driving the anchor point away from the first surface, further lifting the resonator, and generating stress σ1 on the resonator, as shown in Figure 11 The second is that when the pressure sensitive film is subjected to the pressure to be detected, the anchor point deforms tangentially and stretches the resonator, generating stress σ2 on the resonator, as shown in Figure 12 The two stresses mentioned above act together on the resonator, causing a change in its resonant frequency. The detection circuit receives the resonator's vibration signal and, based on the change in the resonator's vibration signal, obtains the pressure data to be detected.

[0163] As a possible implementation, see Figure 13 As shown, the present application example provides a method for preparing a piezoelectric resonant pressure sensor, comprising the following steps:

[0164] Step S10, providing a first wafer 10', such as Figure 14 and Figure 35 shown.

[0165] The first wafer 10 ′ may have a cylindrical structure, a rectangular parallelepiped structure, a prismatic structure, etc., which is not specifically limited here.

[0166] When the first wafer 10 ′ may be an SOI wafer, the first wafer 10 ′ includes a silicon structure layer 12 , a buried oxide layer 13 and a substrate layer 14 which are stacked.

[0167] Step S20: forming a pressure chamber 11 for receiving the pressure to be detected on the first wafer 10', wherein the pressure chamber 11 penetrates the substrate layer 14 of the first wafer 10', thereby obtaining a pressure sensitive component 10, such as Figure 17 and Figure 36 shown.

[0168] A pressure-sensitive film of the piezoelectric resonant pressure sensor is formed between the cavity wall of the pressure cavity 11 close to the silicon structure layer 12 and a surface of the silicon structure layer 12 away from the substrate layer 14 .

[0169] In specific implementation, the pressure chamber 11 can be formed on the substrate layer 14 through an etching process. Specifically, dry etching or wet etching can be used, and dry etching is preferred.

[0170] Step S30, forming a sacrificial layer 70 on the silicon structure layer 12 of the first wafer 10'; the orthographic projection of the sacrificial layer 70 on the silicon structure layer 12 and the orthographic projection of the pressure chamber 11 on the silicon structure layer 12 at least partially overlap, such as Figure 18 、 Figure 19 、 Figure 37 and Figure 38shown.

[0171] During specific implementation, a deposition process may be used to form the sacrificial layer 70 on the silicon structure layer 12 .

[0172] The material of the sacrificial layer 70 can be PSG (phosphosilicate glass), or other sacrificial layer 70 materials such as SiO 2 , Ni, etc.

[0173] Step S40, forming a piezoelectric component 20 on the sacrificial layer 70 and the silicon structure layer 12, the piezoelectric component 20 is used to be electrically connected to an external circuit. The sacrificial layer 70 corresponds to the middle area of the piezoelectric component 20. The piezoelectric component 20 includes a first conductive layer 21, a piezoelectric layer 22, and a second conductive layer 23, at least corresponding to the middle area. The first conductive layer 21, the piezoelectric layer 22, and the second conductive layer 23 are stacked in sequence from the pressure sensitive component 10 to the piezoelectric component 20, as shown in FIG. Figures 20 to 25 as well as Figures 39 to 46 .

[0174] The piezoelectric component 20 can be electrically connected to an external circuit directly or indirectly. In the embodiment provided in the present application, the piezoelectric component 20 is electrically connected to an external circuit through a through silicon via 60 provided on the first wafer 10 ′.

[0175] The first conductive layer 21 and the second conductive layer 23 are used to electrically connect to an external circuit. The first conductive layer 21 and the second conductive layer 23 have different polarities. The first conductive layer 21 can be electrically connected to the external circuit, and the second conductive layer 23 can be grounded. Of course, it is also possible to configure the first conductive layer 21 to be grounded and the second conductive layer 23 to be electrically connected to the external circuit.

[0176] The piezoelectric layer 22 is the main functional layer of the piezoelectric component 20 , and can realize the positive piezoelectric effect and the inverse piezoelectric effect in conjunction with the first conductive layer 21 and the second conductive layer 23 , thereby realizing the detection of the pressure to be detected.

[0177] Step S60: performing a first patterning process on the piezoelectric component 20 to form a through-groove 25 in the middle region of the piezoelectric component 20. The through-groove 25 passes through the middle region, and one end of the through-groove 25 extends to the sacrificial layer 70. Figure 28 and Figure 46 .

[0178] Step S70, releasing the sacrificial layer 70 through the through groove 25, see Figure 29 and Figure 48 .

[0179] When the above technical solution is adopted, a sacrificial layer 70 is formed on the silicon structure layer 12 of the first wafer 10 ′. After the piezoelectric component 20 is formed, the sacrificial layer 70 is removed.

[0180] The primary function of sacrificial layer 70 is to provide the necessary structural support for the subsequent formation of piezoelectric assembly 20. Because sacrificial layer 70 corresponds to the central region of piezoelectric assembly 20, after sacrificial layer 70 is released and removed through through-grooves 25, the central region of piezoelectric assembly 20 is left suspended above silicon structural layer 12. This central region of piezoelectric assembly 20 forms a resonator.

[0181] After the sacrificial layer 70 is removed, a gap exists between the middle region of the piezoelectric component 20 and the silicon structure layer 12, and the gap forms the resonant cavity 24. The size of the space occupied by the sacrificial layer 70 is the size of the resonant cavity 24.

[0182] The portion of piezoelectric assembly 20 that encloses the sidewalls of resonant cavity 24 forms the anchor point of the piezoelectric resonant pressure sensor. One end of the anchor point is supported by silicon structure layer 12 of pressure-sensitive assembly 10, and the other end is connected to the resonator. The anchor point serves as a bridge between pressure-sensitive assembly 10 and the resonator, suspending the resonator above pressure-sensitive assembly 10. It also serves to connect the pressure-sensitive film and support the resonator.

[0183] When the pressure to be detected enters pressure chamber 11 from its open end and acts on the chamber wall near silicon structure layer 12, the pressure-sensitive film deforms under the influence of the pressure to be detected, bending toward piezoelectric component 20. The pressure-sensitive film transmits this deformation and stress to the anchor point. The anchor point further transmits the pressure and deformation to the resonator, causing the resonator's vibration frequency to change. The external power supply receives and analyzes the changes in the resonator's vibration frequency to obtain data such as the magnitude and direction of the pressure to be detected.

[0184] The side walls of the resonant cavity 24 form anchor points, eliminating the need for additional support structures between the piezoelectric component 20 and the pressure sensitive component 10 as anchor points. This simplifies the structure of the piezoelectric resonant pressure sensor and reduces its size.

[0185] Since the orthographic projection of the sacrificial layer 70 on the silicon structure layer 12 at least partially overlaps with the orthographic projection of the pressure cavity 11 on the silicon structure layer 12, after removing the sacrificial layer 70 to form the resonant cavity 24, the orthographic projection of the resonant cavity 24 on the silicon structure layer 12 at least partially overlaps with the orthographic projection of the pressure cavity 11 on the silicon structure layer 12, thereby ensuring that the pressure-sensitive film can bend toward the piezoelectric component 20 when subjected to the pressure to be detected, that is, the resonant cavity 24 can provide deformation space for the pressure-sensitive film.

[0186] Since the side cavity wall of the resonant cavity 24 forms an anchor point, when the orthographic projection of the resonant cavity 24 on the silicon structure layer 12 at least partially overlaps with the orthographic projection of the pressure cavity 11 on the silicon structure layer 12, it can ensure that the anchor point is in contact with the pressure-sensitive film, thereby ensuring that the anchor point converts the stress on the pressure-sensitive film into stress on the resonator, thereby achieving a change in the vibration frequency of the resonator.

[0187] In a possible implementation, step S40: forming the piezoelectric component 20 on the sacrificial layer 70 and the silicon structure layer 12 includes the following steps:

[0188] Step S401 : forming a first conductive layer 21 on the sacrificial layer 70 and the silicon structure layer 12 .

[0189] Specifically, a deposition process may be used to form the first conductive layer 21 on the sacrificial layer 70 and the silicon structure layer 12 .

[0190] It should be noted that a seed layer should be deposited before depositing the first conductive layer 21 to ensure the quality of the piezoelectric layer 22 .

[0191] Step S402 : forming a piezoelectric layer 22 on the first conductive layer 21 and the silicon structure layer 12 .

[0192] Specifically, the piezoelectric layer 22 may be formed on the first conductive layer 21 and the silicon structure layer 12 by using a deposition process.

[0193] Step S403 : forming a second conductive layer 23 on the piezoelectric layer 22 and the silicon structure layer 12 to obtain a piezoelectric component 20 .

[0194] Specifically, a deposition process may be used to form the second conductive layer 23 on the piezoelectric layer 22 and the silicon structure layer 12 .

[0195] It should be noted that the second conductive layer 23 may include a top electrode, such as Figure 6 The second conductive layer 23 may also include two top electrodes, such as Figure 1 、 Figure 7 and Figure 8 As shown. Of course, the second conductive layer 23 may also include three, four or more top electrodes, which is not specifically limited here. When the second conductive layer 23 includes one top electrode, the top electrode acts as a driving electrode and also as a detection electrode.

[0196] Specifically, when the top electrode is electrically connected to the driving circuit, it can drive the resonator to vibrate, and the top electrode acts as a driving electrode. When the top electrode is electrically connected to the detection circuit, it can output the vibration signal of the resonator to obtain data of the pressure to be detected. In this case, the top electrode acts as a detection electrode.

[0197] During specific operation, the top electrode may be alternately electrically connected to the drive circuit and the detection circuit. For example, the top electrode may be alternately electrically connected to the drive circuit within the first 0.5 second, electrically connected to the detection circuit within the second 0.5 second, electrically connected to the drive circuit within the third 0.5 second, and electrically connected to the detection circuit within the fourth 0.5 second, and the electrical connections between the top electrode and the drive circuit and the detection circuit may be alternately arranged.

[0198] When the second conductive layer 23 includes two top electrodes, one top electrode may be set as a driving electrode electrically connected to the driving circuit, and the other top electrode may be set as a detecting electrode electrically connected to the detecting circuit.

[0199] When the second conductive layer 23 includes more top electrodes, some of the top electrodes may be configured as driving electrodes electrically connected to the driving circuit, and other top electrodes may be configured as detecting electrodes electrically connected to the detecting circuit.

[0200] The first conductive layer 21 and the second conductive layer 23 are both made of conductive metal, for example, Mo, Au, Pt, Al, etc., preferably Mo.

[0201] In some embodiments, after step S40: forming the piezoelectric component 20 on the sacrificial layer 70 and the silicon structure layer 12, and before step S50: performing a first patterning process on the piezoelectric component 20 to form a through groove 25 in the middle area of the piezoelectric component 20, the preparation method of the piezoelectric resonant pressure sensor provided in the embodiment of the present application also includes step S50: forming a first bonding ring 15 on the silicon structure layer 12; the first bonding ring 15 corresponds to the four edges of the silicon structure layer 12.

[0202] This facilitates bonding of the pressure sensitive component 10 to the subsequent cover 30 .

[0203] After the sacrificial layer 70 is released through the through groove 25 , the preparation method provided in the embodiment of the present application further includes the following steps:

[0204] Step S80 , providing a second wafer 30 ′. A second bonding ring 32 is provided on the second wafer 30 ′. The first bonding ring 15 matches the second bonding ring 32 .

[0205] In step S90 , a second patterning process is performed on the surface of the second wafer 30 ′ provided with the second bonding ring 32 to obtain a cover space 31 and a cover 30 .

[0206] In step S100 , the first bonding ring 15 and the second bonding ring 32 are bonded together, and the piezoelectric component 20 is located in the covering space 31 .

[0207] It should be noted that, in the embodiment provided in the present application, the piezoelectric layer 22 may be electrically connected to an external circuit through a through silicon via 60 .

[0208] In specific implementation, the through silicon vias 60 can be set on the pressure sensitive component 10, such as Figure 3 As shown. The TSVs 60 can also be arranged on the cover 30, as shown. Figure 4 and Figure 5 Of course, in a specific implementation, part of the through silicon vias 60 can be set on the pressure sensitive component 10, and the other part of the through silicon vias 60 can be set on the cover 30.

[0209] The number of through-silicon vias 60 can be two, three, four, or more. The number of through-silicon vias 60 used to connect to the second conductive layer 23 can be the same as the number of top electrodes included in the second conductive layer 23, and they correspond one to one. The number of through-silicon vias 60 used to connect to the first conductive layer 21 can be one, two, or more, and is not specifically limited here.

[0210] For ease of understanding, the preparation method of the piezoelectric resonant pressure sensor provided in the embodiment of the present application is described below in a possible implementation manner in conjunction with the accompanying drawings. Of course, this is not a specific limitation here.

[0211] In one example, the piezoelectric resonant pressure sensor is prepared using the method for preparing the piezoelectric resonant pressure sensor provided in the embodiment of the present application. Figure 3 The piezoelectric resonant pressure sensor shown.

[0212] The specific steps are as follows:

[0213] Step S11, providing a first wafer 10'. Figure 14 As shown, the first wafer 10' is provided with at least two through-silicon vias 60. The first wafer 10' further includes a silicon structure layer 12, a buried oxide layer 13 and a substrate layer 14 stacked in sequence. The through-silicon vias 60 penetrate the first wafer 10' from the substrate layer 14 to the silicon structure layer 12.

[0214] Step S12, as Figure 15 As shown, a front lead electrode 40 ′ is deposited on a side of the substrate layer 14 away from the silicon structure layer 12 .

[0215] The material of the front lead electrode 40 ′ is a conductive metal. For example, the material of the lead electrode 40 may be Al, Au, Pt, etc., preferably Al or Au.

[0216] Step S13, patterning the front lead electrode 40' to form a lead electrode 40 electrically connected to the through silicon via 60, such as Figure 16 The lead electrode 40 cooperates with the through silicon via 60 so as to facilitate electrical connection between the through silicon via 60 and an external circuit.

[0217] Step S14: forming a pressure chamber 11 for receiving the pressure to be detected on the first wafer 10', wherein the pressure chamber 11 penetrates the substrate layer 14 of the first wafer 10', thereby obtaining a pressure sensitive component 10, such as Figure 17 shown.

[0218] Step S15, depositing a front sacrificial layer 70' on the silicon structure layer 12 of the first wafer 10', such as Figure 18 shown.

[0219] Step S16, etching the front sacrificial layer 70' to form the sacrificial layer 70, such as Figure 19 shown.

[0220] Step S17, depositing the first conductive layer 21' on the sacrificial layer 70 and the silicon structure layer 12, as shown in FIG. Figure 20 shown.

[0221] Step S18, etching the front first conductive layer 21' to form the first conductive layer 21, such as Figure 21 The first conductive layer 21 is electrically connected to at least one through silicon via 60 .

[0222] Step S19, depositing a front piezoelectric layer 22' on the first conductive layer 21 and the silicon structure layer 12, as shown in FIG. Figure 22 shown.

[0223] Step S110, etching the front piezoelectric layer 22' to form the piezoelectric layer 22, such as Figure 23 shown.

[0224] Step S111, depositing a front second conductive layer 23' on the piezoelectric layer 22 and the silicon structure layer 12, as shown in FIG. Figure 24 shown.

[0225] Step S112, patterning the second conductive layer 23' to obtain the second conductive layer 23, such as Figure 25 The second conductive layer 23 is electrically connected to at least one through silicon via 60 , while preventing the first conductive layer 21 from being electrically connected to the second conductive layer 23 .

[0226] Step S113, depositing a front third conductive layer 15' on the second conductive layer 23 and the silicon structure layer 12, as shown in FIG. Figure 26 The material of the front third conductive layer 15' depends on the bonding method of the final cover 30 and the pressure sensitive component 10, preferably Al-Ge bonding, in which case the material of the front third conductive layer 15' can be Al.

[0227] Step S114, etching the front third conductive layer 15' to obtain the first bonding ring 15, such as Figure 27 The first bonding ring 15 covers the four edges of the silicon structure layer 12 .

[0228] Step S115: etching the piezoelectric component 20 to form a through-groove 25. The through-groove 25 passes through the middle area of the piezoelectric component 20, and one end of the through-groove 25 extends to the sacrificial layer 70. Figure 28 shown.

[0229] Step S116, releasing the sacrificial layer 70 to form the resonant cavity 24, as shown in FIG. Figure 29 shown.

[0230] Step S117, providing a second wafer 30', such as Figure 30 shown.

[0231] Step S118, depositing a front fourth conductive layer 32' on one side of the second wafer 30', such as Figure 31 shown.

[0232] Step S119, patterning the fourth conductive layer 32' to obtain the second bonding ring 32, such as Figure 32 The second bonding ring 32 matches the first bonding ring 15 .

[0233] Step S120, etching the side of the second wafer 30' provided with the second bonding ring 32 to obtain a covering space 31, as shown in FIG. Figure 33 Specifically, dry etching or wet etching can be used.

[0234] Step S121, prepare the getter 50, such as Figure 34 The getter 50 is disposed in the cover space 31 , and the getter 50 may be a thin film getter or other structure capable of maintaining a vacuum inside the piezoelectric resonant pressure sensor.

[0235] Specifically, the suction component 50 is used to absorb the gas molecules released from the piezoelectric component 20, the pressure sensitive component 10 and other devices after the first wafer 10' and the second wafer 30' are bonded together, so that the inside of the piezoelectric resonant pressure sensor is maintained in a vacuum state to ensure the vacuum degree of the vacuum chamber, ensure the measurement accuracy and sensitivity of the piezoelectric resonant pressure sensor, and extend the service life of the piezoelectric resonant pressure sensor.

[0236] Step S122: Align and bond the first bonding ring 15 and the second bonding ring 32 in a vacuum environment, so that the first wafer 10' and the second wafer 30' are bonded and connected, and the result is as follows: Figure 3 The piezoelectric resonant pressure sensor shown.

[0237] In another example, the piezoelectric resonant pressure sensor is prepared by the method for preparing the piezoelectric resonant pressure sensor provided in the embodiment of the present application. Figure 5 The piezoelectric resonant pressure sensor shown.

[0238] The specific steps are as follows:

[0239] Step S21, providing a first wafer 10', such as Figure 35 The first wafer 10' comprises a silicon structure layer 12, a buried oxide layer 13 and a substrate layer 14 which are stacked in sequence.

[0240] Step S22: forming a pressure chamber 11 for receiving the pressure to be detected on the first wafer 10', wherein the pressure chamber 11 penetrates the substrate layer 14 of the first wafer 10' to obtain a pressure sensitive component 10, such as Figure 36 shown.

[0241] Step S23, depositing a front sacrificial layer 70' on the silicon structure layer 12 of the first wafer 10', such as Figure 37 shown.

[0242] Step S24, etching the front sacrificial layer 70' to form the sacrificial layer 70, such as Figure 38 shown.

[0243] Step S25, depositing the first conductive layer 21' on the sacrificial layer 70 and the silicon structure layer 12, as shown in FIG. Figure 39 shown.

[0244] Step S26, etching the front first conductive layer 21' to form the first conductive layer 21, such as Figure 40 shown.

[0245] Step S27, depositing a front piezoelectric layer 22' on the first conductive layer 21 and the silicon structure layer 12, as shown in FIG. Figure 41 shown.

[0246] Step S28, etching the front piezoelectric layer 22' to form the piezoelectric layer 22, as shown in FIG. Figure 42 As shown, the piezoelectric layer 22 is provided with a communication hole 211 ′.

[0247] Step S29, depositing a front second conductive layer 23' on the piezoelectric layer 22 and the silicon structure layer 12, as shown in FIG. Figure 43 At the same time, when the second conductive layer 23 ′ is deposited on the piezoelectric layer 22 and the silicon structure layer 12 using a deposition process, part of the metal fills the connecting hole 211 ′ to form a connecting lead 211 , which is electrically connected to the first conductive layer 21 .

[0248] Step S210, patterning the second conductive layer 23' to obtain the second conductive layer 23 as shown in FIG. Figure 44 At the same time, during the process of patterning the front second conductive layer 23 ′, a connection base is formed at a position corresponding to the connection lead 211 , and the connection base is electrically connected to the connection lead 211 .

[0249] Step S211, depositing a front third conductive layer 15' on the second conductive layer 23 and the silicon structure layer 12, such as Figure 45 shown.

[0250] Step S212, etching the front third conductive layer 15' to obtain the first bonding ring 15, such as Figure 46 The first bonding ring 15 covers the edges of the silicon structure layer 12. At the same time, when etching the third conductive layer 15', connecting wires 26 are formed at the positions corresponding to the connecting holes 211' and on the second conductive layer 23.

[0251] Step S213: Etch the piezoelectric component 20 to form a through-groove 25. The through-groove 25 passes through the middle area of the piezoelectric component 20, and one end of the through-groove 25 extends to the sacrificial layer 70. Figure 47 shown.

[0252] Step S214: releasing the sacrificial layer 70 to form the resonant cavity 24. Figure 48 shown.

[0253] Step S215, providing a second wafer 30', such as Figure 49 As shown, at least two through silicon vias 60 are provided on the second wafer 30 ′.

[0254] Step S216: depositing the front lead electrode 40' on one side of the second wafer 30'. Figure 50 As shown, the front lead electrode 40 ′ is electrically connected to the through silicon via 60 .

[0255] Step S217, patterning the front lead electrode 40' to form a lead electrode 40 electrically connected to the through silicon via 60, such as Figure 51 The lead electrode 40 cooperates with the through silicon via 60 so as to facilitate electrical connection between the through silicon via 60 and an external circuit.

[0256] Step S218, depositing a front fourth conductive layer 32' on one side of the second wafer 30', such as Figure 52 As shown, the second wafer 30 ′ has a surface for arranging the lead electrodes 40 and a surface for arranging the front fourth conductive layer 32 ′ opposite to each other. The front fourth conductive layer 32 ′ is electrically connected to the through silicon via 60 .

[0257] Step S219, patterning the fourth conductive layer 32', such as Figure 53 As shown, a second bonding ring 32 is obtained. The second bonding ring 32 matches the first bonding ring 15.

[0258] Step S220, etching the side of the second wafer 30' where the second bonding ring 32 is provided to obtain a covering space 31, as shown in FIG. Figure 54 Specifically, dry etching or wet etching can be used.

[0259] Step S221, prepare the getter 50, such as Figure 55The air suction member 50 is disposed in the cover space 31 .

[0260] Step S222: Align and bond the first bonding ring 15 and the second bonding ring 32 in a vacuum environment, so that the first wafer 10' and the second wafer 30' are bonded and connected, and the result is as follows: Figure 5 At this time, the first conductive layer 21 is electrically connected to the TSV 60 through the connecting lead 211 , the connecting lead 26 , and the connecting seat, and the second conductive layer 23 is electrically connected to the TSV 60 through the connecting lead 26 .

[0261] Finally, it should be noted that the above embodiments are merely specific implementations of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A piezoelectric resonant pressure sensor, characterized in that: include: A pressure sensitive component having a first surface and a second surface disposed opposite to each other; the pressure sensitive component having a pressure cavity penetrating the second surface, wherein the pressure to be detected acts on a cavity wall of the pressure cavity close to the first surface; a piezoelectric component electrically connected to an external circuit via a through-silicon via; the piezoelectric component is supported on all sides by the first surface, and a middle region of the piezoelectric component is suspended above the first surface, so as to form a resonant cavity between the middle region and the first surface; An orthographic projection of the resonant cavity on the second surface at least partially overlaps with an orthographic projection of the pressure cavity on the second surface.

2. The piezoelectric resonant pressure sensor according to claim 1, wherein: The piezoelectric component includes a first conductive layer, a piezoelectric layer, and a second conductive layer, wherein the first conductive layer and the second conductive layer are electrically connected to the external circuit through the through silicon via; the first conductive layer and the second conductive layer have different polarities; At least corresponding to the middle area, the first conductive layer, the piezoelectric layer and the second conductive layer are stacked in sequence from the pressure sensitive component to the piezoelectric component; and, corresponding to the middle area, the first conductive layer, the piezoelectric layer and the second conductive layer protrude in the direction away from the pressure sensitive component to form the resonant cavity.

3. The piezoelectric resonant pressure sensor according to claim 2, wherein: At least two through-silicon vias are provided on the pressure sensitive component, the first conductive layer is electrically connected to the external circuit through at least one of the through-silicon vias, and the second conductive layer is electrically connected to the external circuit through at least another through-silicon via.

4. The piezoelectric resonant pressure sensor according to claim 2, wherein: The piezoelectric resonant pressure sensor further includes a cover disposed on the first surface; a cover space is provided on a side of the cover facing the first surface, and the piezoelectric component is located in the cover space.

5. The piezoelectric resonant pressure sensor according to claim 4, wherein: At least two through silicon vias are provided on the cover, the first conductive layer is electrically connected to the external circuit through at least one of the through silicon vias, and the second conductive layer is electrically connected to the external circuit through at least another through silicon via.

6. The piezoelectric resonant pressure sensor according to claim 4, wherein: The cover is in vacuum connection with the first surface; The piezoelectric resonant pressure sensor further includes an air absorber disposed in the cover space, and the air absorber is used to absorb gas after the cover is vacuum-connected to the pressure sensitive component.

7. The piezoelectric resonant pressure sensor according to claim 4, wherein: A first bonding ring is provided on the first surface, and the first bonding ring corresponds to the four edges of the pressure sensitive component; a second bonding ring is provided on the side of the cover close to the first surface, and the first bonding ring and the second bonding ring are bonded to connect the cover to the first surface.

8. The piezoelectric resonant pressure sensor according to claim 2, wherein: A through groove is provided on the piezoelectric component, and the through groove passes through the middle area and is communicated with the resonant cavity.

9. The piezoelectric resonant pressure sensor according to claim 3 or 5, characterized in that: The piezoelectric resonant pressure sensor further includes a lead electrode disposed on a side of the through silicon via away from the piezoelectric component, and the lead electrode is electrically connected to the through silicon via.

10. The piezoelectric resonant pressure sensor according to claim 5, wherein: The piezoelectric component also includes a connecting lead and a communicating lead, wherein the connecting lead is arranged on the first surface and the piezoelectric layer; one end of the communicating lead is electrically connected to the first conductive layer, and the other end of the connecting lead passes through the piezoelectric layer and is electrically connected to one end of the connecting lead, and the other end of the connecting lead is electrically connected to the silicon through-hole corresponding to the first conductive layer.

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