Multi-array ultrasonic transducer, multi-array ultrasonic transducer manufacturing method and endoscope

Abstract

The present invention relates to the technical field of ultrasonic transducers, and in particular to a multi-array ultrasonic transducer, a method for manufacturing a multi-array ultrasonic transducer, and an endoscope. The multi-array ultrasonic transducer comprises a substrate layer, a piezoelectric layer, and a grounding layer which are sequentially arranged in contact with each other. The substrate layer is used to provide a support basis for the piezoelectric layer. A plurality of conductive protrusions arranged in an array are provided on one side of the substrate layer facing the piezoelectric layer. Each conductive protrusion is embedded in the piezoelectric layer. An end of each conductive protrusion facing the grounding layer forms a piezoelectric functional portion with the piezoelectric layer between the grounding layer. The piezoelectric functional portion is used to generate or receive ultrasonic waves. The piezoelectric layer between two adjacent conductive protrusions forms a blocking portion. The piezoelectric material itself has a certain sound wave attenuation coefficient. By controlling the minimum thickness value of the blocking portion, the crosstalk of ultrasonic waves between adjacent piezoelectric functional portions can be blocked, thereby avoiding crosstalk of ultrasonic waves between two adjacent piezoelectric functional portions.

Description

Technical Field

[0001] The present invention relates to the technical field of ultrasonic transducers, and in particular to a multi-array ultrasonic transducer, a method for manufacturing the multi-array ultrasonic transducer, and an endoscope. Background Art

[0002] The ultrasonic transducer for vascular endoscopy is a device embedded in a vascular endoscope. The ultrasonic transducer for endoscopy is installed on an ultrasonic probe and introduced into the blood vessel. It is used for ultrasonic imaging inside the blood vessel and can display information such as the vascular wall structure, blood flow velocity in the artery, and vascular wall thickness in real time. It has important clinical applications in evaluating lesions such as vascular stenosis, thrombosis, and aneurysm.

[0003] At present, the transducers used in vascular endoscopes mainly include single-element transducers, multi-element transducers and annular array transducers. The single-element transducer is the most basic form of vascular endoscope transducer. It consists of a single sensor and is usually used for traditional intravascular ultrasound imaging. The single-element transducer is relatively simple and low-cost, and is suitable for general intravascular ultrasound imaging applications. The multi-element transducer uses an array composed of multiple sensors, which can simultaneously receive ultrasound signals from different directions. The multi-element transducer can improve the imaging resolution and the detection depth of deep tissues, and can also realize beam forming and beam direction control, so as to obtain clearer and more accurate ultrasound images. The annular array transducer has omnidirectional imaging capabilities and can achieve 360° omnidirectional imaging coverage, thereby providing a more comprehensive and detailed observation of the inside of the blood vessel. It is widely used in scenarios that require a comprehensive assessment of the condition of the vascular wall, such as the assessment of the integrity of the vascular wall and the detection of lesions such as aneurysms. The advantage of this technology is that it can provide imaging without blind spots, enabling doctors to diagnose and evaluate vascular lesions more accurately, providing important support for clinical diagnosis and treatment.

[0004] Both the multi-element transducer and the annular array transducer are provided with a plurality of transducer units arranged in an array, and each transducer unit comprises a grounding layer, a piezoelectric functional part and a conductive column which are arranged in sequence. The piezoelectric functional part is an ultrasonic wave generating and receiving component, which is crucial to the detection accuracy of the transducer. In the existing multi-element transducer and annular array transducer, the piezoelectric functional parts of each transducer unit are arranged at intervals, and the gap between two adjacent piezoelectric functional parts is filled with a blocking glue for blocking the propagation of ultrasonic waves, thereby avoiding crosstalk between the ultrasonic waves generated by the two adjacent piezoelectric functional parts. When processing a transducer of this structure, it is necessary to first process a piezoelectric layer on the inner side of the grounding layer, and then open an isolation groove in the piezoelectric layer to divide the piezoelectric layer into a plurality of piezoelectric functional parts, and then fill the isolation groove between two adjacent piezoelectric functional parts with blocking glue. The processing flow is cumbersome, resulting in a high processing cost for the multi-element transducer and the annular array transducer. Summary of the invention

[0005] The technical problem to be solved by the present invention is that the existing multi-element transducer and ring array transducer need to open an isolation groove between two adjacent piezoelectric functional parts, and need to fill the isolation groove with blocking glue, which makes the processing process cumbersome.

[0006] In order to solve the above technical problems, the purpose of the present invention is to provide a multi-array ultrasonic transducer, comprising a base layer, a piezoelectric layer and a ground layer which are arranged in sequence, the base layer is used to provide a support basis for the piezoelectric layer, a side of the base layer facing the piezoelectric layer is provided with a plurality of conductive protrusions arranged in an array, each of the conductive protrusions is embedded in the piezoelectric layer, and the end of each conductive protrusion facing the ground layer forms a piezoelectric functional part with the piezoelectric layer between the ground layer, and the piezoelectric functional part is used to generate or receive ultrasonic waves; the piezoelectric layer located between two adjacent conductive protrusions forms a blocking part;

[0007] The partial wave of the ultrasonic wave propagating along the axial direction of the conductive protrusion is defined as a longitudinal wave, and the wave of the ultrasonic wave propagating perpendicular to the axial direction of the conductive protrusion is defined as a transverse wave, and the blocking portion is used to block the propagation of the transverse wave between two adjacent piezoelectric functional portions;

[0008] and,

[0009] Wherein, d is the thickness of the blocking part, in μm; T is the thickness of the piezoelectric functional part, in μm, Vt is the propagation speed of the transverse wave in the blocking part, in m / s, and Vp is the propagation speed of the longitudinal wave in the blocking part, in m / s.

[0010] As a preferred solution, the piezoelectric layer is arranged on the base layer by means of additive manufacturing.

[0011] As a preferred embodiment, the multi-array ultrasonic transducer includes a matching layer arranged on a side of the ground layer away from the piezoelectric layer, and the matching layer is used to improve the transmittance of the longitudinal wave.

[0012] A method for manufacturing the above-mentioned multi-array ultrasonic transducer comprises the following steps:

[0013] Step S1, disposing a piezoelectric layer on a side of a base layer provided with a conductive protrusion by additive processing, and processing a blocking portion and a piezoelectric functional portion on the base layer;

[0014] Step S2, magnetron sputtering a ground layer on a side of the piezoelectric layer away from the base layer.

[0015] As a preferred solution, after step S1 and before step S2, the method includes:

[0016] Step S11: polarizing the piezoelectric layer by using corona poling.

[0017] As a preferred solution, the base layer is a flexible base, and after step S2, the following steps are included:

[0018] Step S3, bending the flexible substrate into a ring structure, and making the ground layer face the outside of the ring structure;

[0019] Step S4: sleeve the annular structure onto the outside of the catheter traction wire of the endoscope.

[0020] As a preferred solution, after step S4, the following steps are included:

[0021] Step S5, filling a backing layer in the gap between the catheter traction wire and the annular structure, wherein the backing layer is used to absorb noise and is also used to fix the annular structure to the catheter traction wire.

[0022] As a preferred solution, after step S5, the following steps are included:

[0023] Step S6: disposing a matching layer outside the ground layer.

[0024] As a preferred solution, the base layer includes a flexible insulating board, and the step S1 includes:

[0025] Step S001, preparing a flexible insulating board;

[0026] Step S002, coating one side of the flexible insulating board with a conductive material, wherein the thickness of the conductive material coating is equal to the height of the conductive protrusion;

[0027] Step S003: etching to form a plurality of conductive protrusions on the conductive material-plated surface of the flexible insulating board.

[0028] An endoscope is provided with the above-mentioned multi-array ultrasonic transducer.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] The ultrasonic transducer of the present invention comprises a substrate layer, a piezoelectric layer and a grounding layer which are arranged in sequence, the substrate layer is used to provide a support basis for the piezoelectric layer, a plurality of conductive protrusions arranged in an array are provided on the side of the substrate layer facing the piezoelectric layer, each conductive protrusion is embedded in the piezoelectric layer, and the end of each conductive protrusion facing the grounding layer forms a piezoelectric functional part with the piezoelectric layer between the grounding layer, and the piezoelectric functional part is used to generate or receive ultrasonic waves; the piezoelectric layer located between two adjacent conductive protrusions forms a blocking part; the piezoelectric material itself has a certain sound wave attenuation coefficient, and by controlling the minimum thickness value of the blocking part, the crosstalk of ultrasonic waves between adjacent piezoelectric functional parts can be blocked, and the partial wave of ultrasonic waves propagating along the axial direction of the conductive protrusion is defined as a longitudinal wave, and the wave of ultrasonic waves propagating perpendicular to the axial direction of the conductive protrusion is defined as a transverse wave, and the thickness d of the blocking part satisfies When required, the blocking portion can block the propagation of transverse waves between two adjacent piezoelectric functional portions. Therefore, the ultrasonic transducer of the present invention can avoid ultrasonic crosstalk between two adjacent piezoelectric functional portions by controlling the spacing distance between two adjacent conductive protrusions and using the piezoelectric layer to form a blocking portion. There is no need to process an isolation groove between two adjacent piezoelectric functional portions, nor is there any need to fill the isolation groove with blocking glue, which greatly simplifies the processing technology of the ultrasonic transducer and reduces the processing cost of the ultrasonic transducer. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a schematic structural diagram of the ultrasonic transducer of the present invention;

[0032] Figure 2 It is a schematic diagram of the structure in which the ultrasonic transducer of the present invention is fixedly sleeved on the outside of the catheter traction wire;

[0033] Figure 3 A schematic diagram of the positional relationship between the excitation array element and the #1 receiving array element and the #2 receiving array element selected when performing crosstalk simulation on the ultrasonic transducer of the present invention;

[0034] Figure 4 A diagram showing the result of receiving signals after crosstalk simulation of the ultrasonic transducer of the present invention;

[0035] In the figure, 1, base layer, 2, piezoelectric layer, 21, piezoelectric functional part, 22, blocking part, 3, grounding layer, 4, conductive protrusion, 5, matching layer, 6, backing layer, 7, catheter traction wire. DETAILED DESCRIPTION

[0036] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0037] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "top", "bottom", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. It should be understood that the terms "first", "second", etc. are used in the present invention to describe various information, but such information should not be limited to these terms, which are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present invention, the "first" information may also be referred to as the "second" information, and similarly, the "second" information may also be referred to as the "first" information.

[0038] like Figures 1 to 4 As shown, a preferred embodiment of the multi-array ultrasonic transducer of the present invention comprises a substrate layer 1, a piezoelectric layer 2 and a grounding layer 3 which are sequentially arranged in contact with each other, the substrate layer 1 is used to provide a support basis for the piezoelectric layer 2, a plurality of conductive protrusions 4 arranged in an array are provided on one side of the substrate layer 1 facing the piezoelectric layer 2, each conductive protrusion 4 is embedded in the piezoelectric layer 2, and an end of each conductive protrusion 4 facing one end of the grounding layer 3 and the piezoelectric layer 2 between the grounding layer 3 form a piezoelectric functional portion 21, and the piezoelectric functional portion 21 is used to generate or receive ultrasonic waves; the piezoelectric layer 2 located between two adjacent conductive protrusions 4 forms a blocking portion 22;

[0039] The partial wave of ultrasonic wave propagating along the axial direction of the conductive protrusion 4 is defined as a longitudinal wave, and the wave of ultrasonic wave propagating perpendicular to the axial direction of the conductive protrusion 4 is defined as a transverse wave. The blocking portion 22 is used to block the transverse wave from propagating between two adjacent piezoelectric functional portions 21.

[0040] and,

[0041] Wherein, d is the thickness of the blocking portion 22 between two adjacent conductive protrusions 4, in μm; T is the thickness of the piezoelectric functional portion 21, in μm, Vt is the propagation speed of the transverse wave in the blocking portion 22, in m / s, and Vp is the propagation speed of the longitudinal wave in the blocking portion 22, in m / s. The piezoelectric functional portion is relatively thin and in the form of a thin film, and plays the role of a piezoelectric film of an existing ultrasonic transducer.

[0042] Specifically, the base layer 1 is used to provide support for the piezoelectric layer 2, the piezoelectric layer 2 is located between the ground layer 3 and the base layer 1, and the piezoelectric functional part is located between the conductive protrusion 4 and the ground layer 3. After the conductive protrusion is energized, under the action of the conductive protrusion 4 and the ground layer 3, the piezoelectric functional part can emit ultrasonic waves. Array element crosstalk refers to the situation in array signal processing where, due to the dense arrangement of array elements and the mutual influence between signals, an array element in the array receives information not only from the target signal, but usually receives interference signals from adjacent array elements. Array element crosstalk is a problem that must be eliminated first in the design of array transducers. The piezoelectric layer 2 located between two adjacent conductive protrusions 4 forms a blocking part 22; the piezoelectric material itself has a certain acoustic wave attenuation coefficient, and by controlling the minimum thickness value of the blocking part 22, the crosstalk of ultrasonic waves between adjacent piezoelectric functional parts 21 can be blocked. In this embodiment, the sub-wave of ultrasonic wave propagating along the axial direction of the conductive protrusion 4 is defined as longitudinal wave, and the wave of ultrasonic wave propagating perpendicular to the axial direction of the conductive protrusion 4 is defined as transverse wave. The research team uses COMSOL finite element acoustic analysis technology to simulate different spacing values ​​of the conductive protrusions 4 when using polymer materials polyvinyl idene fluoride polymer (PVDF) and lead zirconate titanate piezoelectric ceramic transducer (PZT). The simulation results are shown in Appendix 1. The crosstalk sensitivity is greater than -20db and is unusable. From the data in Table 1, it can be seen that when the spacing of the conductive protrusions 4 is greater than or equal to one tenth of the ultrasonic transverse wave wavelength λ, the crosstalk sensitivity can be controlled within the usable range. Therefore, the spacing d between adjacent conductive protrusions 4 needs to meet the following requirements:

[0043]

[0044] Wherein λ is the transverse wave wavelength, in μm, and d is the spacing between adjacent conductive protrusions 4, that is, the thickness of the blocking portion 22, in μm;

[0045] because

[0046] Wherein, λ is the wavelength of the shear wave, in μm; Vt is the sound velocity of the shear wave in the corresponding piezoelectric material, in m / s; fc is the operating frequency of the ultrasonic transducer, in Mhz;

[0047] and,

[0048] Wherein, fc is the operating frequency of the ultrasonic transducer, in Mhz; Vp is the sound velocity of the longitudinal wave in the piezoelectric functional portion 21, in m / s; t is the thickness of the piezoelectric functional portion 21, in μm;

[0049] Combining formulas 1 to 3, we can get:

[0050] Among them, d is the thickness of the blocking part 22, unit is μm; T is the thickness of the piezoelectric functional part 21, unit is μm, Vt is the propagation speed of the transverse wave in the blocking part 22, unit is m / s, and Vp is the propagation speed of the longitudinal wave in the blocking part 22, unit is m / s.

[0051] Therefore, the thickness d of the blocking portion 22 satisfies When required, the blocking portion 22 can block the propagation of transverse waves between two adjacent piezoelectric functional portions 21. Therefore, the ultrasonic transducer of the present invention can avoid ultrasonic wave crosstalk between two adjacent piezoelectric functional portions 21 by controlling the spacing distance between two adjacent conductive protrusions 4 and using the piezoelectric layer 2 to form the blocking portion 22. It is not necessary to open an isolation groove between two adjacent conductive protrusions 4, nor is it necessary to fill the isolation groove with blocking glue, which greatly simplifies the processing technology of the ultrasonic transducer and reduces the processing cost of the ultrasonic transducer.

[0052] Among them, the piezoelectric layer 2 is arranged on the base layer 1 by means of additive manufacturing. Specifically, the processing of the piezoelectric layer 2 can be carried out by sputtering, solution method, sol-gel method or single crystal growth method. When the sputtering method is adopted, a physical vapor deposition technology, such as magnetron sputtering, is used to deposit a piezoelectric material such as aluminum nitride or barium titanate on the side of the base layer 1 where a columnar electrode is provided to form a piezoelectric layer 2. The thickness of the piezoelectric functional part 21 is equal to the difference between the thickness of the deposited layer and the height of the conductive protrusion 4. The thickness of the piezoelectric functional part 21 is controlled by controlling the deposition thickness. The piezoelectric layer 2 fills the gap between adjacent conductive protrusions 4 to form a blocking part 22. When the piezoelectric layer 2 is processed by the solution method, the precursor of the piezoelectric material is dissolved in a solvent, and then the piezoelectric layer 2 is formed on the side of the base layer 1 where the conductive protrusion 4 is provided by solution spin coating, spraying or dipping, and the piezoelectric layer 2 is crystallized and solidified by heat treatment. When the piezoelectric layer 2 is processed by the sol-gel method, the precursor of the piezoelectric material is dissolved in a solvent to form a sol, and then a gel is formed on the side of the substrate layer 1 provided with the conductive protrusions 4 through a gelation reaction, and finally it is crystallized into the piezoelectric layer 2 through heat treatment. When the piezoelectric layer 2 is processed by the single crystal growth method: a single crystal sheet of the piezoelectric material is directly grown on the side of the substrate layer 1 provided with the conductive protrusions 4 by chemical vapor deposition or physical vapor deposition.

[0053] In this embodiment, the multi-array ultrasonic transducer includes a matching layer 5 disposed on the side of the ground layer 3 away from the piezoelectric layer 2, and the matching layer 5 is used to improve the transmittance of the longitudinal wave. Specifically, as an important component of the medical ultrasonic transducer, the matching layer 5 can achieve acoustic impedance matching or transition, greatly improve the acoustic energy transmittance and sensitivity between human tissue and piezoelectric material, and can broaden the bandwidth of the transducer while reducing distortion. For a given frequency, its acoustic impedance is the geometric mean of the product of the acoustic impedance of the piezoelectric material and the human tissue. The resin material Epo-Tek 301 is usually used as the material matching layer 5.

[0054] The grounding layer 3 is used as the grounding electrode of the transducer, and the grounding layer 3 is electrically connected to each piezoelectric functional part 21. The grounding layer 3 can be deposited on the surface of the piezoelectric layer 2 by magnetron sputtering. The grounding layer 3 prepared by this method is uniform, dense and has strong adhesion. The grounding layer 3 is provided with a connecting portion protruding from the outside of the piezoelectric functional part 21 and the matching layer 5, and the connecting portion is used to connect the grounding wire.

[0055] A method for manufacturing the above-mentioned multi-array ultrasonic transducer comprises the following steps:

[0056] Step S1, disposing the piezoelectric layer 2 on the side of the base layer 1 provided with the conductive protrusion 4 by additive processing, and processing the blocking portion 22 and the piezoelectric functional portion 21 on the base layer 1;

[0057] Step S2 , magnetron sputtering a ground layer 3 on a side of the piezoelectric layer 2 facing away from the substrate layer 1 .

[0058] Wherein, after step S1 and before step S2, the following steps are included:

[0059] Step S11, polarizing the piezoelectric layer 2 by means of corona poling.

[0060] Specifically, by polarizing the piezoelectric material, the electric dipole moment inside the piezoelectric material is arranged in a directional manner, thereby ensuring the reliability and stability of its piezoelectric performance. Since the transducer prepared in this embodiment is small in size, corona poling is adopted. Corona poling can produce a relatively stable polarization state, which helps to improve the performance stability and long-term reliability of the piezoelectric film. In addition, the operation is simple and the non-contact method is easy to polarize small-sized piezoelectric films.

[0061] The multi-array transducer processed in this embodiment is a ring-shaped array endovascular ultrasound transducer. To facilitate the processing of the ring-shaped array endovascular ultrasound transducer, in this embodiment, the base layer 1 is set as a flexible base. After step S2, the following steps are included:

[0062] Step S3, bending the flexible substrate into a ring structure, and making the ground layer 3 face the outside of the ring structure;

[0063] Step S4, sleeve the annular structure onto the outer side of the catheter traction wire 7 of the endoscope.

[0064] By setting the base layer 1 as a flexible insulating board, before bending the base layer 1, the flexible insulating board is flat, which is convenient for etching the conductive protrusions used as electrodes. After the transducer is processed, the flexible insulating board is bent into a ring shape to achieve shaping of the flexible insulating board, so that the ultrasonic transducer can be installed in the vascular endoscope.

[0065] Further, after step S4, the following steps are included:

[0066] Step S5 , filling the gap between the catheter traction wire 7 and the annular structure with a backing layer 6 , wherein the backing layer 6 is used to absorb noise and to fix the annular structure to the catheter traction wire 7 .

[0067] The backing layer 6 is used to absorb noise, and the backing layer 6 is also used to fix the annular structure to the catheter traction wire 7. Specifically, the acoustic impedance of the backing layer 6 material is greater than that of the piezoelectric layer 2 material, and its thickness is greater than four times the ultrasonic wavelength, which can absorb background noise. In this embodiment, the backing layer 6 material is a mixture of epoxy resin and tungsten powder.

[0068] In this embodiment, after step S5, the following steps are included:

[0069] Step S6 , disposing the matching layer 5 outside the ground layer 3 .

[0070] Further, the base layer 1 comprises a flexible insulating board, and before step S1, the steps include:

[0071] Step S001, preparing a flexible insulating board;

[0072] Step S002, coating one side of the flexible insulating board with a conductive material, wherein the thickness of the conductive material coating is equal to the height of the conductive protrusion 4;

[0073] Step S003: etching to form a plurality of conductive protrusions 4 on the conductive material-plated surface of the flexible insulating board.

[0074] Specifically, the flexible insulating board is a polyimide board. In this embodiment, the conductive protrusions 4 are etched out after the conductive material is plated on the flexible insulating board. While etching the conductive protrusions 4, the wires electrically connected to each conductive protrusion 4 can be etched out. After the piezoelectric layer 2 is subsequently deposited on the conductive material-plated surface of the flexible insulating board, the piezoelectric layer 2 can also play a packaging role for the exposed conductive protrusions 4, thereby greatly improving the processing efficiency of the transducer.

[0075] The annular array transducer prepared by this method successfully achieved the requirements of miniaturization and high frequency, and met the transducer performance standards required for vascular endoscopy. This annular array transducer has significant application prospects in vascular endoscopy. Its miniaturization characteristics enable it to easily enter the blood vessels and achieve precise endoscopic operations, while its high-frequency characteristics can provide more detailed vascular structure information, which helps to improve the accuracy and efficiency of clinical diagnosis and treatment. This technology is not only widely used in the field of medical imaging, but also has great potential in biomedical research and treatment.

[0076] In this embodiment, a conductive protrusion 4 and a piezoelectric functional part 21 corresponding to the conductive protrusion 4 constitute an array element. The diameter of the designed 64-element ring array probe is less than 1.5 mm, and the spacing between adjacent conductive protrusions 4 is 20 μm. The research team used COMSOL finite element acoustic analysis technology to conduct a preliminary evaluation of the sensitivity and element crosstalk of the 64-element ring array probe designed for the project; a 55 MHz sinusoidally modulated Gaussian pulse was used as the excitation signal during the simulation. Figure 3 The array element is stimulated as shown, and the probe is set to detect the interference signal received by the receiving array element #1 and the receiving array element #2. The crosstalk signal when the array element spacing is 20μm is as follows Figure 4 As shown, the interference signal VP-P received by the #1 receiving element closer to the excitation element is 2.48V, and the interference signal Vp-p received by the #2 receiving element is 0.0094V. The calculated crosstalk sensitivities are -68.3dB and -179.8dB respectively, indicating that the array element crosstalk of the annular array probe of this embodiment is low and the structure is reasonable.

[0077] An embodiment of an endoscope is provided with the above-mentioned multi-array ultrasonic transducer.

[0078] In summary, the ultrasonic transducer of the present invention comprises a substrate layer 1, a piezoelectric layer 2 and a grounding layer 3 which are arranged in sequence, the substrate layer 1 is used to provide a support basis for the piezoelectric layer 2, a plurality of conductive protrusions 4 arranged in an array are provided on the side of the substrate layer 1 facing the piezoelectric layer 2, each conductive protrusion 4 is embedded in the piezoelectric layer 2, and the end of each conductive protrusion 4 facing the grounding layer 3 forms a piezoelectric functional portion 21 with the piezoelectric layer 2 between the grounding layer 3, and the piezoelectric functional portion 21 is used to generate or receive ultrasonic waves; the piezoelectric layer 2 located between two adjacent conductive protrusions 4 forms a blocking portion 22; the piezoelectric material itself has a certain sound wave attenuation coefficient, and by controlling the minimum thickness value of the blocking portion 22, the ultrasonic wave between adjacent piezoelectric functional portions 21 can be blocked. Crosstalk is defined as the partial wave of ultrasonic wave propagating along the axial direction of the conductive protrusion 4 as a longitudinal wave, and the wave of ultrasonic wave propagating perpendicular to the axial direction of the conductive protrusion 4 as a transverse wave. When the thickness d of the blocking portion 22 meets the requirements, the blocking portion 22 can block the transverse wave from propagating between two adjacent piezoelectric functional portions 21. Therefore, the ultrasonic transducer of the present invention can avoid crosstalk of ultrasonic wave between two adjacent piezoelectric functional portions 21 by controlling the spacing distance between two adjacent conductive protrusions 4 and forming the blocking portion 22 using the piezoelectric layer 2. There is no need to process an isolation groove between two adjacent piezoelectric functional portions 21, nor is there any need to fill the isolation groove with blocking glue, which greatly simplifies the processing technology of the ultrasonic transducer and reduces the processing cost of the ultrasonic transducer.

[0079] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principles of the present invention. These improvements and substitutions should also be regarded as the scope of protection of the present invention.

[0080] Schedule 1

[0081]

Claims

1. A multi-array ultrasonic transducer, characterized in that: The invention comprises a base layer (1), a piezoelectric layer (2) and a grounding layer (3) which are arranged in sequence, wherein the base layer (1) is used to provide a support base for the piezoelectric layer (2), and a plurality of conductive protrusions (4) arranged in an array are provided on one side of the base layer (1) facing the piezoelectric layer (2), and each of the conductive protrusions (4) is embedded in the piezoelectric layer (2), and the end of each of the conductive protrusions (4) facing one end of the grounding layer (3) and the piezoelectric layer (2) between the grounding layer (3) form a piezoelectric functional portion (21), and the piezoelectric functional portion (21) is used to generate or receive ultrasonic waves; the piezoelectric layer (2) located between two adjacent conductive protrusions (4) forms a blocking portion (22); The partial wave of the ultrasonic wave propagating along the axial direction of the conductive protrusion (4) is defined as a longitudinal wave, and the wave of the ultrasonic wave propagating perpendicular to the axial direction of the conductive protrusion (4) is defined as a transverse wave, and the blocking portion (22) is used to block the propagation of the transverse wave between two adjacent piezoelectric functional portions (21); and, Wherein, d is the thickness of the blocking portion (22), in μm; T is the thickness of the piezoelectric functional portion (21), in μm; Vt is the propagation speed of the transverse wave in the blocking portion (22), in m / s; and Vp is the propagation speed of the longitudinal wave in the blocking portion (22), in m / s; Each of the conductive protrusions (4) is columnar, and one conductive protrusion (4) and the piezoelectric functional portion (21) corresponding to the conductive protrusion (4) constitute an array element.

2. The multi-array ultrasonic transducer according to claim 1, characterized in that: The piezoelectric layer (2) is arranged on the base layer (1) by means of additive manufacturing.

3. The multi-array ultrasonic transducer according to claim 1, characterized in that: The multi-array ultrasonic transducer comprises a matching layer (5) arranged on a side of the ground layer (3) away from the piezoelectric layer (2), and the matching layer (5) is used to improve the transmittance of the longitudinal wave.

4. A method for manufacturing a multi-array ultrasonic transducer according to any one of claims 1 to 3, characterized in that: The following steps are involved: Step S1, disposing the piezoelectric layer (2) on the side of the base layer (1) provided with the conductive protrusion (4) by additive processing, and processing the blocking portion (22) and the piezoelectric functional portion (21) on the base layer (1); Step S2: magnetron sputtering a ground layer (3) on the side of the piezoelectric layer (2) facing away from the base layer (1).

5. The method for manufacturing a multi-array ultrasonic transducer according to claim 4, characterized in that: After step S1 and before step S2, the following steps are included: Step S11, polarizing the piezoelectric layer (2) by means of corona poling.

6. The method for manufacturing a multi-array ultrasonic transducer according to claim 4, characterized in that: The base layer (1) is a flexible base, and after step S2, the following steps are included: Step S3, bending the flexible substrate into a ring structure, and making the ground layer (3) face the outside of the ring structure; Step S4, sleeve the annular structure onto the outside of the catheter traction wire (7) of the endoscope.

7. The method for manufacturing a multi-array ultrasonic transducer according to claim 6, characterized in that: After step S4, the following steps are included: Step S5, filling a backing layer (6) in the gap between the catheter traction wire (7) and the annular structure, wherein the backing layer (6) is used to absorb noise, and the backing layer (6) is also used to fix the annular structure to the catheter traction wire (7).

8. The method for manufacturing a multi-array ultrasonic transducer according to claim 7, characterized in that: After step S5, the following steps are included: Step S6, arranging the matching layer (5) on the outside of the ground layer (3).

9. The method for manufacturing a multi-array ultrasonic transducer according to claim 4, characterized in that: The base layer (1) comprises a flexible insulating board, and the step S1 includes: Step S001, preparing a flexible insulating board; Step S002, coating one side of the flexible insulating board with a conductive material, wherein the thickness of the conductive material coating is equal to the height of the conductive protrusion (4); Step S003: using etching to form a plurality of the conductive protrusions (4) on the conductive material-plated surface of the flexible insulating board.

10. An endoscope, characterized in that: The endoscope is provided with the multi-array ultrasonic transducer according to any one of claims 1 to 3.

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