A piezoelectric sensor
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHENZHEN FRIENDCOM TECH DEV
- Filing Date
- 2025-05-21
- Publication Date
- 2026-06-30
Smart Images
Figure CN224435433U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of sensor technology, and in particular to a piezoelectric sensor. Background Technology
[0002] A piezoelectric sensor is a sensor based on the piezoelectric effect, belonging to the categories of self-generating and electromechanical conversion sensors. Its core sensing element is made of piezoelectric material. When the piezoelectric material is subjected to an external force, a charge is generated on its surface. This charge, after being amplified by a charge amplifier and measurement circuit, and undergoing impedance transformation, outputs an electrical signal proportional to the applied force. Piezoelectric sensors are mainly used to measure forces and non-electrical physical quantities that can be converted into electricity. Their main advantages include wide bandwidth, high sensitivity, high signal-to-noise ratio, simple structure, reliable operation, and light weight.
[0003] In existing piezoelectric sensors, the matching layer and the piezoelectric material are important components. To fully utilize the performance of the piezoelectric sensor, the piezoelectric material is in contact with the matching layer, allowing the sensor to couple better with the object being measured. This enables sound waves to propagate more effectively between the piezoelectric material and the object, thereby improving the sensor's accuracy in detecting physical quantities.
[0004] However, when existing piezoelectric materials come into contact with the matching layer, manufacturing process or installation errors may cause the piezoelectric materials to not be precisely placed in the predetermined position. When the piezoelectric material is not accurately positioned, its stress and energy conversion efficiency will change, resulting in differences in sensor performance, such as differences in sensitivity, frequency, and response speed, which in turn affects the accuracy and reliability of sensor measurements.
[0005] In the process of realizing this utility model, the inventors discovered that the prior art has at least the following problems:
[0006] Existing piezoelectric materials are not precisely placed in the intended position due to manufacturing process or installation errors, affecting the accuracy and reliability of sensor measurements. Utility Model Content
[0007] The purpose of this invention is to provide a piezoelectric sensor to solve the technical problem in the prior art where manufacturing process or installation errors result in the piezoelectric material not being precisely placed in the predetermined position, affecting the accuracy and reliability of sensor measurements. The various technical effects of the preferred solutions among the many technical solutions provided by this invention are detailed below.
[0008] To achieve the above objectives, the present invention provides the following technical solution:
[0009] This utility model provides a piezoelectric sensor, comprising: a piezoelectric layer, a circuit board, a first matching layer, and a second matching layer; the piezoelectric layer is electrically connected to the circuit board, and both the piezoelectric layer and the circuit board are located within the cavity of the first matching layer and connected to the first matching layer; the first matching layer is located within the cavity of the second matching layer and connected to the second matching layer.
[0010] The cavity of the first matching layer is provided with a limiting groove and a plurality of limiting protrusions; the shape and longitudinal height of the limiting groove are matched with the shape and longitudinal height of the piezoelectric layer, for placing the piezoelectric layer and limiting the piezoelectric layer; the number, shape and position of the plurality of limiting protrusions are matched with the number, shape and position of the limiting holes provided on the circuit board, for limiting the circuit board.
[0011] Optionally, a connecting boss is provided on the side where the first matching layer is connected to the second matching layer; a connecting groove is provided on the side where the second matching layer is connected to the first matching layer; the first matching layer and the second matching layer are connected through the connecting boss and the connecting groove.
[0012] Optionally, the connecting boss and the connecting groove are clearance-fitted, and the space between the connecting boss and the connecting groove is filled with adhesive.
[0013] Optionally, a plurality of first connection holes are provided on the side where the first matching layer is connected to the second matching layer; a plurality of second connection holes are provided on the side where the second matching layer is connected to the first matching layer; the first matching layer and the second matching layer are connected through the plurality of first connection holes and the plurality of second connection holes.
[0014] Optionally, the plurality of first connecting holes and second connecting holes are evenly distributed on the first matching layer and the second matching layer, and each first connecting hole and each second connecting hole is provided in a one-to-one correspondence.
[0015] Optionally, one side of the circuit board is provided with a plurality of connected positive solder joints and a plurality of connected negative solder joints; the other side of the circuit board is provided with a positive main solder joint connected to the positive solder joints and a negative main solder joint connected to the negative solder joints, and the circuit board is electrically connected to the positive and negative electrodes of the piezoelectric layer through the positive main solder joints and the negative main solder joints.
[0016] Optionally, the piezoelectric sensor further includes a backing layer located on the side of the circuit board away from the first mating layer.
[0017] Optionally, the material of the first matching layer is PPS; the material of the second matching layer is ABS.
[0018] Optionally, the edge thickness of the first matching layer is 2.25mm-2.5mm, and the edge thickness of the second matching layer is 1.1mm-1.3mm.
[0019] Optionally, the piezoelectric layer is made of piezoelectric ceramic.
[0020] Implementing one of the above-described technical solutions of this utility model has the following advantages or beneficial effects:
[0021] The piezoelectric sensor described in this invention has a limiting groove and a limiting boss in the first matching layer. The limiting groove and the limiting boss enable the accurate installation of the piezoelectric layer and the circuit board in the cavity of the first matching layer, ensuring the accuracy and stability of the piezoelectric layer and the circuit board during the installation process, and improving the reliability of subsequent piezoelectric sensor detection. Attached Figure Description
[0022] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. In the drawings:
[0023] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present utility model;
[0024] Figure 2 This is a schematic diagram showing the disassembled structure of the overall structure of an embodiment of this utility model;
[0025] Figure 3 This is a schematic diagram of the bottom structure of the first matching layer in an embodiment of this utility model.
[0026] In the diagram: 1. Piezoelectric layer; 2. Circuit board; 21. Limiting hole; 22. Positive solder joint; 23. Negative solder joint; 24. Positive main solder joint; 25. Negative main solder joint; 3. First matching layer; 31. Limiting groove; 32. Limiting boss; 33. Connecting boss; 34. First connecting hole; 4. Second matching layer; 41. Connecting groove; 42. Second connecting hole. Detailed Implementation
[0027] To make the objectives, technical solutions, and advantages of this utility model clearer, various exemplary embodiments described below will be referenced to the accompanying drawings, which form part of the exemplary embodiments, illustrating various exemplary embodiments that may be adopted to implement this utility model. Unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this disclosure. It should be understood that they are merely examples of processes, methods, and apparatuses consistent with some aspects of this utility model disclosed as detailed in the appended claims, and other embodiments may be used, or structural and functional modifications may be made to the embodiments listed herein without departing from the scope and spirit of this utility model.
[0028] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," etc., indicate the orientation or positional relationship based on the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the referred element must have a specific orientation, or be constructed and operated in a specific orientation. The terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. The term "multiple" means two or more. The terms "connected" and "linked" should be interpreted broadly, for example, they can be fixed connections, detachable connections, integral connections, mechanical connections, electrical connections, communication connections, direct connections, indirect connections through an intermediate medium, and can be the internal connection of two elements or the interaction relationship between two elements. The term "and / or" includes any and all combinations of one or more of the related listed items. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.
[0029] To illustrate the technical solution described in this utility model, specific embodiments are described below, showing only the parts related to the embodiments of this utility model.
[0030] Example:
[0031] like Figure 1-3As shown, this utility model provides a piezoelectric sensor, including: a piezoelectric layer 1, a circuit board 2, a first matching layer 3, and a second matching layer 4; the piezoelectric layer 1 is electrically connected to the circuit board 2, and both the piezoelectric layer 1 and the circuit board 2 are located in the cavity of the first matching layer 3 and connected to the first matching layer 3; the first matching layer 3 is located in the cavity of the second matching layer 4 and connected to the second matching layer 4; a limiting groove 31 and a plurality of limiting protrusions 32 are provided in the cavity of the first matching layer 3; the shape and longitudinal height of the limiting groove 31 match the shape and longitudinal height of the piezoelectric layer 1, and are used to place the piezoelectric layer 1 and limit the piezoelectric layer 1; the number, shape, and position of the plurality of limiting protrusions 32 match the number, shape, and position of the limiting holes 21 provided on the circuit board 2, and are used to limit the circuit board 2.
[0032] Specifically, piezoelectric layer 1 and circuit board 2 are electrically connected to convert piezoelectric signals into electrical signals. When piezoelectric layer 1 is subjected to external forces, such as pressure or vibration, its internal crystals deform, generating a potential difference, i.e., the piezoelectric effect. Circuit board 2 is responsible for receiving this piezoelectric signal and transmitting it to subsequent circuits for processing or analysis. Through this electrical connection, the piezoelectric sensor can convert mechanical energy into electrical energy, enabling the measurement of various physical quantities, such as pressure and acceleration.
[0033] like Figure 2 As shown, in the cavity of the first matching layer 3, a limiting groove 31 and multiple limiting protrusions 32 are provided on the side connected to the piezoelectric layer 1 and the circuit board 2.
[0034] The limiting groove 31 is formed at the bottom of the inner wall of the cavity, away from the opening end of the first matching layer 3 along the axial direction. The limiting groove 31 is designed to facilitate the precise placement of the piezoelectric layer 1, ensure the precise alignment of the piezoelectric layer 1 within the cavity of the first matching layer 3, guarantee sufficient support for the piezoelectric layer 1, prevent positional displacement or detachment of the piezoelectric layer 1 during use, and improve the stability and accuracy of the piezoelectric layer 1 during installation and use.
[0035] It should be noted that the shape and longitudinal height of the limiting groove 31 match the piezoelectric layer 1, allowing the piezoelectric layer 1 to be precisely embedded within it, preventing displacement or wobbling. This improves the connection strength between the piezoelectric layer 1 and the first matching layer 3, ensuring that the piezoelectric layer 1 can uniformly transmit force to the circuit board 2 when subjected to stress, thereby improving the measurement accuracy and stability of the sensor. Simultaneously, the limiting groove 31 simplifies the installation process of the piezoelectric layer 1, improving production efficiency.
[0036] like Figure 2As shown, multiple limiting protrusions 32 are located at the bottom of the inner wall of the cavity of the first matching layer 3, and are positioned around the limiting groove 31. To facilitate the connection between the circuit board 2 and the limiting protrusions 32, limiting holes 21 are provided on the circuit board 2. Specifically, the number, shape, quantity, and position of the limiting protrusions 32 match the limiting holes 21. The multiple limiting protrusions 32 facilitate the connection between the circuit board 2 and the first matching layer 3, thus limiting the circuit board 2. Since the piezoelectric layer 1 is located within the limiting groove 31, the first matching layer 3 can further limit the piezoelectric layer 1.
[0037] In this embodiment, the design of the limiting boss 32 allows the circuit board 2 to be securely mounted on the first matching layer 3. The limiting boss 32 matches the corresponding structure on the circuit board 2, connecting the circuit board 2 to the first matching layer 3 and effectively preventing the circuit board 2 from moving or loosening after installation. This design enhances the connection stability between the circuit board 2 and the first matching layer 3, improving the overall structural strength of the piezoelectric sensor. Furthermore, the cooperation between the limiting boss 32 and the limiting groove 31 forms a double limiting mechanism, tightly fixing the piezoelectric layer 1 within the limiting groove 31, while the circuit board 2 is securely supported by the limiting boss 32, resulting in a tight and stable structure between the piezoelectric layer 1, the circuit board 2, and the first matching layer 3.
[0038] In this embodiment, the piezoelectric layer 1 can be cylindrical in shape, and the limiting groove 31 in the first matching layer 3 is also cylindrical, with the height of the limiting groove 31 matching the height of the piezoelectric layer 1. Additionally, the limiting boss 32 in this embodiment can be optionally disposed on both sides of the limiting groove 31, and the shape of the limiting boss 32 can be cylindrical, with the limiting hole 21 correspondingly selected as a circular hole.
[0039] In this embodiment, the material of the piezoelectric layer 1 is piezoelectric ceramic. Choosing piezoelectric ceramic as the material for the piezoelectric layer 1 in this embodiment not only meets the performance requirements of the piezoelectric sensor but also ensures its reliability and durability.
[0040] In this embodiment, the first matching layer 3 of the piezoelectric sensor is provided with a limiting groove 31 and a limiting boss 32. The setting of the limiting groove 31 and the limiting boss 32 enables the piezoelectric layer 1 and the circuit board 2 to be accurately installed in the cavity of the first matching layer 3, ensuring the accuracy and stability of the piezoelectric layer 1 and the circuit board 2 during the installation process, and improving the reliability of subsequent piezoelectric sensor detection.
[0041] As an optional implementation method, such as Figure 2 , Figure 3As shown, a connecting boss 33 is provided on the side where the first matching layer 3 connects to the second matching layer 4; a connecting groove 41 is provided on the side where the second matching layer 4 connects to the first matching layer 3; the first matching layer 3 and the second matching layer 4 are connected by the connecting boss 33 and the connecting groove 41. Specifically, the connecting boss 33 is a boss extending axially towards the second matching layer 4 to a corresponding height on the outer bottom of the first matching layer 3, and the connecting groove 41 is a groove recessed axially away from the first matching layer 3 on the inner bottom of the second matching layer 4 to a corresponding height. The first matching layer 3 and the second matching layer 4 are connected to each other by the connecting boss 33 and the connecting groove 41. The connecting boss 33 and the connecting groove 41 are coaxially arranged. In this embodiment, by providing the connecting boss 33 and the connecting groove 41, a tight connection between the first matching layer 3 and the second matching layer 4 is ensured, while also improving the overall stability.
[0042] The engagement of the connecting boss 33 and the connecting groove 41 increases the contact area, improves the connection strength, and helps ensure precise alignment during the connection process. It also minimizes performance fluctuations caused by inaccurate positioning of the mating layer. Furthermore, the shapes of the connecting boss 33 and the connecting groove 41 can be designed to match, such as cylindrical or rectangular, to adapt to different application scenarios and requirements. In this embodiment, the connecting boss 33 and the connecting groove 41 are preferably cylindrical.
[0043] The connecting boss 33 and the connecting groove 41 are clearance-fitted, and the space between them is filled with adhesive. Specifically, the clearance fit between the connecting boss 33 and the connecting groove 41 allows for a certain degree of freedom during assembly, facilitating adjustment and calibration. The adhesive further enhances the connection's strength and sealing, preventing interference from the external environment to the internal structure of the piezoelectric sensor. Simultaneously, the adhesive also serves to fix and dampen vibrations, protecting the stability and reliability of the piezoelectric sensor in complex environments.
[0044] As an optional implementation method, such as Figure 2-3 As shown, a plurality of first connection holes 34 are provided on the side where the first matching layer 3 is connected to the second matching layer 4; a plurality of second connection holes 42 are provided on the side where the second matching layer 4 is connected to the first matching layer 3; the first matching layer 3 and the second matching layer 4 are connected through the plurality of first connection holes 34 and the plurality of second connection holes 42.
[0045] Specifically, the first mating layer 3 and the second mating layer 4 can each be provided with multiple first connecting holes 34 and multiple second connecting holes 42 on their connected sides. The first mating layer 3 and the second mating layer 4 can achieve precise alignment through the first connecting holes 34 and the second connecting holes 42, and then be fixed together using screws or other connectors. The design of the first connecting holes 34 and the second connecting holes 42 not only improves the accuracy of positioning but also ensures the stability of the two mating layers during use. It should be noted that the first connecting holes 34 are slotted holes, and the second connecting holes 42 are through holes.
[0046] The plurality of first connecting holes 34 and second connecting holes 42 are evenly distributed on the first matching layer 3 and the second matching layer 4, and each first connecting hole 34 and each second connecting hole 42 are provided in a one-to-one correspondence. It should be noted that the even distribution of the plurality of first connecting holes 34 and second connecting holes 42 on the first matching layer 3 and the second matching layer 4 ensures that the tightening force of the screw is evenly distributed around the perimeter, further improving the firmness of the connection and its resistance to external interference.
[0047] Furthermore, in this embodiment, the connecting boss 33 and the first connecting hole 34 on the first matching layer 3, as well as the connecting groove 41 and the second connecting hole 42 on the first matching layer, can be provided separately or simultaneously.
[0048] In this embodiment, a simultaneous installation of adhesive and screws is preferred. This dual fixation effectively addresses the shortcomings of a single fixing method, providing a more robust and reliable fixing structure for the piezoelectric sensor. Screw fixation provides strong mechanical support, ensuring no loosening occurs between the first matching layer 3 and the second matching layer 4; while adhesive increases the contact area, achieving a more uniform force distribution and avoiding the uneven stress that might result from screw fixation alone. The combined use of both not only improves the connection strength between the matching layers but also enhances the transducer's vibration resistance, ensuring the stability of the piezoelectric sensor during long-term use.
[0049] As an optional implementation method, such as Figure 2 As shown, one side of the circuit board 2 is provided with a plurality of connected positive solder joints 22 and a plurality of connected negative solder joints 23; the other side of the circuit board 2 is provided with a positive main solder joint 24 connected to the positive solder joint 22 and a negative main solder joint 25 connected to the negative solder joint 23. The circuit board 2 is electrically connected to the positive and negative electrodes of the piezoelectric layer 1 through the positive main solder joint 24 and the negative main solder joint 25.
[0050] Specifically, circuit board 2 is electrically connected to piezoelectric layer 1. To ensure the accuracy of the connection between circuit board 2 and piezoelectric layer 1, positive main solder joint 24 and negative main solder joint 25 are provided on circuit board 2, which are connected to the positive and negative terminals of piezoelectric layer 1. The provision of positive solder joint 22 and negative solder joint 23 on circuit board 2 not only simplifies the wiring of circuit board 2 but also improves the current transmission efficiency. The introduction of positive main solder joint 24 and negative main solder joint 25 further enhances the connection stability between circuit board 2 and piezoelectric layer 1, ensuring accurate signal transmission and enabling the piezoelectric sensor to maintain stable electrical performance during operation, thereby improving the working efficiency and reliability of the piezoelectric sensor.
[0051] As an optional implementation, the piezoelectric sensor further includes a backing layer (not shown in the figure), located on the side of the circuit board 2 away from the first mating layer 3, for encapsulating the piezoelectric sensor. In this embodiment, the main function of the backing layer is to provide mechanical support and protection to enhance the overall structural strength of the piezoelectric sensor. The backing layer effectively prevents the circuit board 2 from being damaged by the external environment and ensures that the connection between the circuit board 2 and the piezoelectric layer 1 is not interfered with by external factors, further improving the durability and stability of the piezoelectric sensor. In addition, the backing layer can effectively disperse the heat generated by the piezoelectric sensor during operation, preventing performance degradation or damage due to overheating and extending the service life of the piezoelectric sensor. In this embodiment, the material of the backing layer can be epoxy resin.
[0052] As an optional implementation, the material of the first matching layer 3 is PPS. PPS refers to polyphenylene sulfide (PPS), a linear polymer compound composed of alternating benzene rings and sulfur atoms. The combination of its rigid benzene rings and flexible sulfide bonds gives the material a unique combination of rigidity and flexibility, making it a crystalline polymer (crystallinity can reach 55%-65%). In this embodiment, it can specifically be PPS + 30% glass fiber. PPS + 30% glass fiber has good mechanical properties and thermal stability, which can effectively improve the strength and durability of the first matching layer 3. At the same time, PPS + 40% glass fiber material also has good electrical insulation properties, which can effectively isolate electrical interference between the circuit board 2 and the external environment, further ensuring the accuracy and stability of the signal transmission of the piezoelectric sensor.
[0053] The material of the second matching layer 4 is ABS. It should be noted that ABS is a terpolymer of acrylonitrile (A), butadiene (B), and styrene (S). The relative proportions of these three monomers can be arbitrarily changed to produce various resins. ABS material has excellent processing performance and mechanical strength, meeting the requirements of the piezoelectric sensor for the material of the second matching layer 4. Simultaneously, ABS material has good corrosion resistance, effectively resisting the erosion of the piezoelectric sensor by corrosive substances in the external environment, further protecting the internal structure of the piezoelectric sensor. Furthermore, ABS material also has certain insulating properties, which can isolate the circuit board 2 from electrical interference from the external environment to a certain extent, ensuring the stable operation of the piezoelectric sensor.
[0054] More specifically, the edge thickness of the first matching layer 3 is 2.25mm-2.5mm (preferably 2.25mm), the sound velocity of the first matching layer 3 is 3320m / s, and the density of the first matching layer 3 is 1.7248g / cm3. The edge thickness of the second matching layer 4 is 1.1mm-1.3mm (preferably 1.1mm), the sound velocity of the second matching layer 4 is 1876.38m / s, and the density is 1.1026g / cm3. The above parameters are selected to ensure that the first matching layer 3 can be well matched with the piezoelectric layer 1 and the backing layer, so as to achieve effective transmission of sound waves. The edge thickness setting can ensure structural strength while avoiding excessive reflection and scattering of sound waves at the edge of the first matching layer 3, thereby improving the sensitivity of the sensor. The sound velocity and density of the first matching layer 3 are used to achieve acoustic impedance matching with the piezoelectric layer 1 and the backing layer, reduce energy loss of sound waves when propagating between different media, and thus improve the signal-to-noise ratio and measurement accuracy of the sensor.
[0055] The embodiment is merely a special case and does not indicate that this utility model is implemented in such a way.
[0056] The above description is merely a preferred embodiment of the present utility model. Those skilled in the art will understand that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the present utility model. Furthermore, under the teachings of the present utility model, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the present utility model. Therefore, the present utility model is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present utility model.
Claims
1. A piezoelectric sensor, characterized by, include: The piezoelectric layer (1), circuit board (2), first matching layer (3), and second matching layer (4) are provided. The piezoelectric layer (1) is electrically connected to the circuit board (2). Both the piezoelectric layer (1) and the circuit board (2) are located in the cavity of the first matching layer (3) and are connected to the first matching layer (3). The first matching layer (3) is located in the cavity of the second matching layer (4) and is connected to the second matching layer (4). The cavity of the first matching layer (3) is provided with a limiting groove (31) and a plurality of limiting protrusions (32); the shape and longitudinal height of the limiting groove (31) are matched with the shape and longitudinal height of the piezoelectric layer (1) for placing the piezoelectric layer (1) and limiting the piezoelectric layer (1); the number, shape and setting position of the plurality of limiting protrusions (32) are matched with the number, shape and setting position of the limiting holes (21) provided on the circuit board (2) for limiting the circuit board (2).
2. The piezoelectric sensor of claim 1, wherein, A connecting boss (33) is provided on the side where the first matching layer (3) is connected to the second matching layer (4); a connecting groove (41) is provided on the side where the second matching layer (4) is connected to the first matching layer (3); the first matching layer (3) and the second matching layer (4) are connected through the connecting boss (33) and the connecting groove (41).
3. The piezoelectric sensor of claim 2, wherein, The connecting boss (33) and the connecting groove (41) are fitted with a clearance, and glue is filled between the connecting boss (33) and the connecting groove (41).
4. The piezoelectric sensor according to any one of claims 1-3, characterized in that, The first matching layer (3) is provided with a plurality of first connection holes (34) on the side connected to the second matching layer (4); the second matching layer (4) is provided with a plurality of second connection holes (42) on the side connected to the first matching layer (3); the first matching layer (3) and the second matching layer (4) are connected through the plurality of first connection holes (34) and the plurality of second connection holes (42).
5. The piezoelectric sensor according to claim 4, characterized in that, The plurality of first connecting holes (34) and second connecting holes (42) are evenly distributed on the first matching layer (3) and the second matching layer (4), and each first connecting hole (34) and each second connecting hole (42) are provided in a one-to-one correspondence.
6. The piezoelectric sensor according to claim 1, characterized in that, On one side of the circuit board (2), there are multiple connected positive solder joints (22) and multiple connected negative solder joints (23); on the other side of the circuit board (2), there are positive main solder joints (24) connected to the positive solder joints (22) and negative main solder joints (25) connected to the negative solder joints (23). The circuit board (2) is electrically connected to the positive and negative electrodes of the piezoelectric layer (1) through the positive main solder joints (24) and the negative main solder joints (25).
7. The piezoelectric sensor according to claim 1, characterized in that, The piezoelectric sensor also includes a backing layer located on the side of the circuit board (2) away from the first matching layer (3).
8. The piezoelectric sensor according to claim 1, characterized in that, The material of the first matching layer (3) is PPS; the material of the second matching layer (4) is ABS.
9. The piezoelectric sensor according to claim 1, characterized in that, The edge thickness of the first matching layer (3) is 2.25mm-2.5mm, and the edge thickness of the second matching layer (4) is 1.1mm-1.3mm.
10. The piezoelectric sensor according to claim 1, characterized in that, The material of the piezoelectric layer (1) is piezoelectric ceramic.