Piezoelectric ultrasonic transducer array

Abstract

The piezoelectric ultrasonic transducer array comprises a circuit board and a plurality of transducer units which are arranged on the circuit board and arranged in an array mode, each transducer unit comprises a piezoelectric ceramic piece and a resonator, the resonator is arranged on the piezoelectric ceramic piece, the piezoelectric ceramic piece is arranged on the circuit board, and the resonator is arranged on the circuit board. The piezoelectric ceramic piece is provided with a positive electrode and a negative electrode, the two electrodes are electrically connected with the circuit board through an electric connection structure, the circuit board applies an electric signal to the piezoelectric ceramic piece through the electrodes, and the piezoelectric ceramic piece deforms under the action of the electric signal and further generates vibration to emit ultrasonic waves. The piezoelectric ultrasonic transducer array provided by the utility model has the advantages that the structure is simplified, the cost is low, the assembly process is simplified, and the consistency of resonant frequency and sound pressure level can be ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of ultrasonic transducers, in particular to a piezoelectric ultrasonic transducer array. Background Art

[0002] Ultrasonic transducers are developed and formed by utilizing the characteristics of ultrasonic waves. Among them, piezoelectric ultrasonic transducers utilize the piezoelectric effect of piezoelectric ceramics. When an electrical signal is applied to the surface of the piezoelectric ceramic, it will deform, causing the ceramic to vibrate and emit ultrasonic waves.

[0003] like Figure 1 As shown, conventional piezoelectric ultrasonic transducers generally include a housing 10, a base 20, and a transducer body 30. The transducer body 30 is mounted on the base 20 and includes at least a piezoelectric material 31. The housing 10 covers the transducer body 30. The top surface of the housing 10 has a mesh, which primarily protects the internal components from scratches and prevents dust and debris from entering. Two pins 40 are provided on either side of the base 20. These pins 40 are connected to the upper and lower electrodes of the piezoelectric material 31 via corresponding connecting wires 50, respectively. The pins 40 enable plug-in electrical connection and fixation.

[0004] However, when existing single piezoelectric ultrasonic transducers are used to form a piezoelectric ultrasonic transducer array, they have the following defects: 1. After the array is formed, an additional protective shell is added to the existing single shell, resulting in redundant shell functions on the existing single transducer. At the same time, after the array is formed, the base part needs to be integrated into the array base through pins, resulting in redundant base and pin structures on the existing single transducer. Therefore, the original structure has disadvantages such as structural redundancy and high cost when used in a piezoelectric ultrasonic transducer array. In addition, due to the structural redundancy, the assembly process is also relatively complex, making it difficult to ensure the consistency of the resonant frequency and sound pressure level of the transducer unit. 2. The electrical connection of existing single piezoelectric ultrasonic transducers is mainly achieved by manual spot welding of leads, which inevitably leads to disadvantages such as inconsistent appearance, uneven solder joints, local cold solder joints, and burns to the conductive layer on the surface of the piezoelectric material during the welding process. At the same time, because the leads are thin and fragile, they are prone to breakage during assembly, circulation, and use. At the same time, the leads need to be coated with soft glue for protection, and the consistency of the glue coating is difficult to ensure. Utility Model Content

[0005] The purpose of the utility model is to provide a piezoelectric ultrasonic transducer array with a simplified structure, low cost, simplified assembly process and the ability to ensure consistency of resonance frequency and sound pressure level.

[0006] In order to achieve the above object, the utility model provides a piezoelectric ultrasonic transducer array, including circuit board and set up on the circuit board and arrange into array form's multiple transducer units, every transducer unit includes piezoelectric ceramic sheet and resonator, the resonator sets up on piezoelectric ceramic sheet, piezoelectric ceramic sheet sets up on the circuit board, piezoelectric ceramic sheet has two electrodes of positive and negative, two electrodes are connected with circuit board through electric connection structure, the circuit board passes through the electrode and is connected with piezoelectric ceramic sheet and applies electric signal, piezoelectric ceramic sheet is deformed under the action of electric signal, and then generates vibration and emits ultrasonic wave.

[0007] In a preferred embodiment, the plurality of transducer units are arranged in a circular array, a rectangular array, or a polygonal array.

[0008] In a preferred embodiment, the transducer unit further comprises a metal sheet disposed between the resonator and the upper surface of the piezoelectric ceramic sheet.

[0009] In a preferred embodiment, the transducer unit further comprises an elastic support disposed between the circuit board and the lower surface of the piezoelectric ceramic sheet.

[0010] In a preferred embodiment, the two electrodes of the piezoelectric ceramic sheet are located on the same surface of the piezoelectric ceramic sheet, or are located on the upper and lower surfaces of the piezoelectric ceramic sheet, respectively.

[0011] In a preferred embodiment, the electric connection structure is a pin integrated on the circuit board, the pin comprising a first pin and a second pin, one end of the first pin being electrically connected with the circuit board, and the other end being electrically connected with one of the electrodes of the piezoelectric ceramic sheet; one end of the second pin being electrically connected with the circuit board, and the other end being electrically connected with the other electrode of the piezoelectric ceramic sheet.

[0012] In a preferred embodiment, the lower surface of the piezoelectric ceramic sheet is provided with two electrode pads insulated from each other, and the top ends of the first pin and the second pin are electrically connected with the respective electrode pads, respectively.

[0013] In a preferred embodiment, the piezoelectric ceramic sheet is further provided with a through hole penetrating through the upper and lower surfaces of the piezoelectric ceramic sheet, and the second pin is electrically connected with the upper surface of the piezoelectric ceramic sheet through the through hole.

[0014] In a preferred embodiment, the electric connection structure comprises at least one elastic connecting piece and at least one pin integrated on the circuit board, one end of the elastic connecting piece is electrically connected with the circuit board, and the other end is electrically connected with the metal sheet; one end of the pin is electrically connected with the circuit board, and the other end is electrically connected with the lower surface of the piezoelectric ceramic sheet; or the electric connection structure comprises a first elastic connecting piece and a second elastic connecting piece, one end of the first elastic connecting piece is electrically connected with the circuit board, and the other end is electrically connected with the metal sheet; one end of the second elastic connecting piece is electrically connected with the circuit board, and the other end is electrically connected with the lower surface of the piezoelectric ceramic sheet.

[0015] In a preferred embodiment, the pin is a thimble or a spring sheet, the lower end of the thimble or the spring sheet is fixedly connected with the circuit board, and the upper end is in contact with the lower surface of the piezoelectric ceramic sheet.

[0016] In a preferred embodiment, the electric connection structure is a soft electric connection structure, and / or the soft electric connection structure is an FPC circuit board.

[0017] Compared with the prior art, the utility model has the advantages of the following beneficial effects:

[0018] 1. In the utility model, the PCB board is directly used as the common base of the transducer units for arraying when the piezoelectric ultrasonic transducer array is assembled, the base and the pin structure of the existing single piezoelectric transducer are omitted, and the shell structure of the existing single piezoelectric transducer is also removed, so that the structure and the assembly process of the piezoelectric ultrasonic transducer array are greatly simplified, the product development and production cycle are reduced, and the cost is lowered; in addition, since the transducer units share a base, the consistency of the resonant frequency and the sound pressure level of the transducer units can be ensured.

[0019] 2. The utility model utilizes the mature PCB board structure and process, and improves the electric connection structure of the existing piezoelectric ultrasonic transducer, so that the problems of appearance defect, quality defect and poor product performance consistency caused by the lead connection and the protective glue of the existing piezoelectric ultrasonic transducer are avoided. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 It is a structure diagram of the existing piezoelectric ultrasonic transducer;

[0021] Figure 2 It is a structure diagram of the piezoelectric ultrasonic transducer array (circular array) of the utility model;

[0022] Figure 3 It is a structure diagram of the piezoelectric ultrasonic transducer array (square array) of the utility model;

[0023] Figure 4 It is a structure diagram of the piezoelectric ultrasonic transducer array (polygonal array) of the utility model;

[0024] Figure 5 It is the side view structural schematic drawing of piezoelectric ultrasonic transducer array (square array) of the utility model;

[0025] Figure 6 It is the structural schematic drawing of single transducer unit (connecting structure is thimble) in embodiment 1 of the utility model;

[0026] Figure 7 It is the structural schematic drawing of single transducer unit (connecting structure is elastic sheet) in embodiment 1 of the utility model;

[0027] Figure 8 It is the structural schematic drawing of single transducer unit (connecting structure is elastic connecting sheet + thimble, and elastic connecting sheet and circuit board are overlapped) in embodiment 2 of the utility model;

[0028] Figure 9 It is the structural schematic drawing of single transducer unit (connecting structure is elastic connecting sheet + thimble, and elastic connecting sheet and circuit board are inserted) in embodiment 2 of the utility model;

[0029] Figure 10 It is the structural schematic drawing of single transducer unit (connecting structure is flexible circuit board) in embodiment 2 of the utility model.

[0030] Reference signs are:

[0031] 1, circuit board, 2, transducer unit, 21, resonator, 22, metal sheet, 23, piezoelectric ceramic sheet, 24, elastic support, 25, first pin, 26, second pin, 27, elastic connecting piece, 3, electrode pad, 4, through hole, 5, flexible circuit board. DETAILED DESCRIPTION

[0032] The specific embodiments of the utility model are described in detail below, but it should be understood that the protection scope of the utility model is not limited by the specific embodiments.

[0033] Unless otherwise explicitly indicated, in the entire specification and claims, the term "comprises" or its variants such as "contains" or "includes" and the like will be understood to include the stated element or component, but not to exclude the presence of other elements or components.

[0034] As Figures 2-4 Indicated, a piezoelectric ultrasonic transducer array disclosed by the utility model includes circuit board 1 and multiple transducer units 2 arranged in array form and arranged on circuit board 1, and when implementing, transducer unit 2 can be arranged but not limited to circular array, rectangular array or polygonal array and the like.

[0035] AsFigure 5 As shown, the plurality of transducer units 2 share the circuit board 1 as a common base, thereby omitting the base structure of the prior single piezoelectric transducer, and since the transducer units 2 are directly formed on the circuit board 1, the pin structure of the prior single piezoelectric transducer is also omitted, thereby simplifying the structure and assembly process of the piezoelectric ultrasonic transducer array formed after the arraying, reducing the production cost of the product and shortening the development and production cycle; in addition, since the transducer units 2 share a base, the consistency of the resonance frequency and sound pressure level of the transducer units 2 can be ensured. In implementation, the circuit board can be realized by using the mature PCB circuit board on the market.

[0036] In this embodiment, the piezoelectric ceramic sheet 23 is directly formed on the circuit board 1, and the transducer units 2 are directly formed on the piezoelectric ceramic sheet 23. Figures 6-9 As shown, each transducer unit 2 specifically comprises a resonator 21, a metal sheet 22, a piezoelectric ceramic sheet 23 and an elastic support 24, wherein the resonator 21 is located on the upper surface of the metal sheet 22, specifically at the center of the upper surface of the metal sheet 22, and it is in the shape of a horn with the opening upward, which can effectively make the ultrasonic waves gather in the central part of the transducer unit 2 and effectively radiate the ultrasonic waves. In implementation, the resonator 21 can be made of a material with a large Young's modulus / density, preferably but not limited to aluminum.

[0037] The metal sheet 22 is arranged on the upper surface of the piezoelectric ceramic sheet 23, and it forms a compound vibrator with the piezoelectric ceramic sheet 23, providing a much lower bending vibration frequency than the radial and thickness direction vibration frequency. When an electric signal is applied to the compound vibrator, the piezoelectric ceramic sheet 23 will deform due to its piezoelectric effect, causing its vibration and emitting ultrasonic waves. In implementation, the metal sheet 22 is made of a metal material with a large Young's modulus (such as Young's modulus > 40 GPa), preferably but not limited to aluminum, copper, nickel-chromium-titanium alloy, etc.

[0038] The piezoelectric ceramic sheet 23 is arranged on the circuit board 1 through the elastic support 24, which constrains the above-mentioned compound vibrator to the circuit board 1 and provides a vibration buffering effect when the compound vibrator vibrates. It should be noted that in some other alternative embodiments, the above-mentioned metal sheet 22 and the elastic support 24 here can be omitted, i.e. not necessary. In implementation, the piezoelectric ceramic sheet 23 is preferably but not limited to lead zirconate titanate film PZT, aluminum nitride AlN, zinc oxide ZnO, etc.

[0039] The piezoelectric ceramic sheet 23 has two positive and negative electrodes on it, which are electrically connected to the circuit board 1 through an electric connection structure. The circuit board 1 applies an electric signal to the piezoelectric ceramic sheet 23 through the two electrodes, and the piezoelectric ceramic sheet 23 deforms under the action of the electric signal, thereby producing vibration and emitting ultrasonic waves. The present application does not limit the setting position of the two electrodes on the piezoelectric ceramic sheet 23, which can be set on the same surface (such as the upper surface or the lower surface) of the piezoelectric ceramic sheet 23, or respectively on the upper and lower surfaces of the piezoelectric ceramic sheet 23, etc.

[0040] In addition, preferably, the electric connection structure of the transducer unit 2 is improved to overcome the problems of poor appearance, poor quality and poor product performance consistency caused by the existing lead connection and the protective glue thereof. In specific implementation, the electric connection structure of the transducer unit 2 is not limited, that is, in addition to the existing lead connection form, other electric connection structures with better connection effect than the lead connection form are suitable for the utility model.

[0041] The electric connection structure of the transducer unit of the utility model will be described below with several specific embodiments.

[0042] Embodiment 1

[0043] In combination Figure 6 and Figure 7 As shown in the figure, in this embodiment 1, two electrode pads 3 are made on the lower surface of the piezoelectric ceramic sheet 23, and the two electrode pads 3 are arranged in insulation between them.

[0044] The electric connection structure is a pin integrated on the circuit board 1, and the pin specifically includes a first pin 25 and a second pin 26, wherein one end of the first pin 25 is electrically connected with the circuit board 1, and the other end is electrically connected with one electrode of the piezoelectric ceramic sheet 23, specifically with one electrode pad 3; one end of the second pin 26 is electrically connected with the circuit board 1, and the other end is electrically connected with the other electrode of the piezoelectric ceramic sheet 23, specifically with the other electrode pad 3.

[0045] If both electrodes of the piezoelectric ceramic sheet 23 are located on its lower surface, only two pins need to be electrically connected with two electrode pads 3 respectively; if the two electrodes of the piezoelectric ceramic sheet 23 are located on its upper and lower surfaces respectively, one pin is electrically connected with the corresponding electrode pad 3, and then the electric signal needs to be introduced to the upper surface of the piezoelectric ceramic sheet 23 through other structures, such as through a through hole 4 penetrating the upper and lower surfaces of the piezoelectric ceramic sheet 23 and being electrically connected with the upper surface of the piezoelectric ceramic sheet 23.

[0046] In implementation, the above two pins can be realized in the form of mature top pins or spring sheets on the circuit board 1. Among them, the bottom end of the top pin or spring sheet is fixedly connected with the circuit board 1, and the top end is in contact with the corresponding electrode pad 3 on the piezoelectric ceramic sheet 23. Since the top pin or spring sheet has a certain elasticity and a certain pre-compression, it can adapt to the real-time deformation of the piezoelectric ceramic sheet 23. In implementation, the top pin is preferably made of materials with good rigidity, wear resistance and corrosion resistance, such as stainless steel, copper aluminum, etc.

[0047] Preferably, in this embodiment, both pins are located in the hollow elastic support 24, which can play a certain protective role.

[0048] Embodiment 2

[0049] Combine Figure 8 and Figure 9 As shown, in this second embodiment, the electrical connection structure includes at least one elastic connector 27 and at least one pin integrated on the circuit board 1. One end of the elastic connector 27 is electrically connected to the circuit board 1, specifically by overlapping or plugging. In addition to overlapping or plugging, welding can also be used to ensure the reliability of the connection. The other end of the elastic connector 27 is electrically connected to the metal sheet 22.

[0050] One end of the pin is electrically connected to the circuit board 1, and the other end is electrically connected to the lower surface of the piezoelectric ceramic sheet 23. The pin is connected to the circuit board 1 and the piezoelectric ceramic sheet 23 in the same manner as described above. The bottom end of the pin can be fixedly connected to the circuit board 1, and the top end contacts the electrode pad 3 on the lower surface of the piezoelectric ceramic sheet 23. As in Example 1, during implementation, the pin can also be implemented in the form of a more mature ejector pin or spring on the circuit board 1.

[0051] Of course, in other alternative embodiments, the pins in this embodiment can also be replaced with elastic connectors 27, that is, the electrical connection structure includes a first elastic connector and a second elastic connector, wherein one end of the first elastic connector is electrically connected to the circuit board 1, and the other end is electrically connected to the metal sheet 22; one end of the second elastic connector is electrically connected to the circuit board 1, and the other end is electrically connected to the lower surface of the piezoelectric ceramic sheet 23.

[0052] Furthermore, the elasticity of the elastic connector 27 can be achieved in various ways, such as by designing the connector into a spring shape or by providing a certain degree of curvature, all of which are applicable to this embodiment. Furthermore, this embodiment does not limit the number and placement of the elastic connectors 27 and pins. For example, multiple elastic connectors 27 can be evenly distributed along the circumference of the edge of the metal sheet 22.

[0053] Example 3

[0054] like Figure 10 As shown, in this embodiment, the electrical connection structure is a flexible printed circuit board (FPC), which connects the positive and negative poles of the piezoelectric ceramic and is fixed to the circuit board. Compared with the electrical connection structures of Examples 1 and 2, the flexible printed circuit board less constrains the vibration of the piezoelectric ceramic.

[0055] The utility model discloses the advantage lies in, 1, the utility model discloses when the piezoelectric ultrasonic transducer array is formed, directly take the PCB board as the common base of the transducer unit for arraying, omit the base and pin structure of the existing single piezoelectric transducer, in addition, the shell structure of the existing single piezoelectric transducer is also removed, thereby greatly simplifying the structure and assembly process of piezoelectric ultrasonic transducer array, thereby reduce the product development and production cycle, reduce the cost, in addition, since the transducer unit shares a base, can guarantee the consistency of transducer unit resonance frequency and sound pressure level. 2, the utility model utilizes mature PCB board structure and technology, through the improvement to the electric connection structure of the existing piezoelectric ultrasonic transducer, thereby avoid the appearance bad, quality bad and product performance consistency poor of the lead connection and its protective glue of the existing piezoelectric ultrasonic transducer.

[0056] The foregoing description of specific exemplary embodiments of the present application is intended to be illustrative only and is not intended to limit the application to the precise forms described. Many modifications and variations are possible in light of the above teachings without departing from the spirit or essential characteristics of the present application. The exemplary embodiments were chosen and described in order to explain the principles of the present application and its practical application and to allow others skilled in the art to understand the present application for various exemplary embodiments with various modifications as are suited to the particular use contemplated. The scope of the present application is intended to be defined by the claims and their equivalents.

Claims

1. A piezoelectric ultrasonic transducer array, characterized by, The application relates to a circuit board and a plurality of transducer units arranged in an array on the circuit board, each of the transducer units comprising a piezoelectric ceramic sheet and a resonator arranged on the piezoelectric ceramic sheet, the piezoelectric ceramic sheet being arranged on the circuit board, the piezoelectric ceramic sheet having two electrodes, the two electrodes being electrically connected to the circuit board through an electrical connection structure, the circuit board applying an electrical signal to the piezoelectric ceramic sheet through the two electrodes, the piezoelectric ceramic sheet being deformed under the action of the electrical signal to generate vibration and emit ultrasonic waves.

2. A piezoelectric ultrasonic transducer array as claimed in claim 1, characterized in that, The plurality of transducer units are arranged in a circular array, a rectangular array or a polygonal array.

3. A piezoelectric ultrasonic transducer array as claimed in claim 1, characterized in that, The transducer unit further comprises a metal sheet arranged between the resonator and the upper surface of the piezoelectric ceramic sheet, and / or the transducer unit further comprises an elastic support arranged between the circuit board and the lower surface of the piezoelectric ceramic sheet.

4. A piezoelectric ultrasonic transducer array as claimed in claim 1, characterized in that, The two electrodes of the piezoelectric ceramic sheet are located on the same surface of the piezoelectric ceramic sheet or on the upper and lower surfaces of the piezoelectric ceramic sheet respectively.

5. A piezoelectric ultrasonic transducer array as claimed in claim 1, characterized in that, The electrical connection structure is a pin integrated on the circuit board, the pin comprising a first pin and a second pin, one end of the first pin being electrically connected to the circuit board and the other end being electrically connected to one of the electrodes of the piezoelectric ceramic sheet, one end of the second pin being electrically connected to the circuit board and the other end being electrically connected to the other electrode of the piezoelectric ceramic sheet.

6. A piezoelectric ultrasonic transducer array as claimed in claim 5, characterized in that, The lower surface of the piezoelectric ceramic sheet is provided with two electrode pads insulated from each other, the top ends of the first pin and the second pin being electrically connected to the respective electrode pads.

7. A piezoelectric ultrasonic transducer array as claimed in claim 6, characterized in that, The piezoelectric ceramic sheet is further provided with a through hole penetrating the upper and lower surfaces of the piezoelectric ceramic sheet, the second pin being electrically connected to the upper surface of the piezoelectric ceramic sheet through the through hole.

8. A piezoelectric ultrasonic transducer array as claimed in claim 3, characterized in that, The electrical connection structure comprises at least one elastic connecting member and at least one pin integrated on the circuit board, one end of the elastic connecting member being electrically connected to the circuit board and the other end being electrically connected to the metal sheet, one end of the pin being electrically connected to the circuit board and the other end being electrically connected to the lower surface of the piezoelectric ceramic sheet, or the electrical connection structure comprises a first elastic connecting member and a second elastic connecting member, one end of the first elastic connecting member being electrically connected to the circuit board and the other end being electrically connected to the metal sheet, one end of the second elastic connecting member being electrically connected to the circuit board and the other end being electrically connected to the lower surface of the piezoelectric ceramic sheet.

9. A piezoelectric ultrasonic transducer array as claimed in claim 5 or 8, characterized in that, The pin is a thimble or a spring sheet, the lower end of the thimble or the spring sheet being fixedly connected to the circuit board and the upper end being in contact with the lower surface of the piezoelectric ceramic sheet.

10. A piezoelectric ultrasonic transducer array as claimed in claim 1, characterized in that, The electrical connection structure is a soft electrical connection structure, and / or the soft electrical connection structure is an FPC circuit board.

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