A method for manufacturing a three-dimensional ultrasonic transducer

Abstract

This invention discloses a method for manufacturing a three-dimensional ultrasonic transducer. The method involves cutting and potting a piezoelectric ceramic wafer, and improving the acoustic wave transmission efficiency from the piezoelectric ceramic wafer to the imaging medium by preparing a matching layer. The front side of the piezoelectric ceramic composite material with the matching layer is cut to form a stress-relieving grid. Under controlled temperature and pressure, three-dimensional die casting is performed, transforming the piezoelectric ceramic composite material from a planar surface into a three-dimensional curved surface. During the die casting process, the gaps in the stress-relieving grid increase, releasing the stress generated during the three-dimensional forming process. This invention's three-dimensional ultrasonic transducer overcomes the limitation of traditional transducers with a limited viewing angle in a certain direction, significantly improving spatial resolution and making it suitable for high-resolution, large-field-of-view three-dimensional imaging.

Description

Technical Field

[0001] This invention relates to the manufacturing technology of ultrasonic transducers, and more specifically to a method for manufacturing a three-dimensional ultrasonic transducer. Background Technology

[0002] Ultrasonic transducers have wide applications in medical imaging, industrial inspection, and many other fields, and their manufacturing technology originated in the early 20th century. This technological development benefited from advances in physics, particularly the discovery and application of the piezoelectric effect, which provided crucial theoretical foundations and experimental support for the development of ultrasonic technology. The piezoelectric effect refers to the physical phenomenon where a material generates an electric field when mechanical stress is applied, or deforms when an electric field is applied. The key component of an ultrasonic transducer is the piezoelectric material, and the selection and processing of these materials are core aspects of the manufacturing process. Early transducers typically used natural piezoelectric materials such as quartz. Although these materials have relatively stable physical properties, their low piezoelectric efficiency and processing difficulties limited their widespread use. Subsequently, synthetic piezoelectric materials, such as lead zirconate titanate (PZT) ceramics, were developed and used. Due to their superior piezoelectric properties and higher manufacturability, they gradually replaced natural piezoelectric materials. This shift greatly promoted the development of ultrasonic transducer manufacturing processes and expanded their application scope.

[0003] Imaging ultrasound transducers, widely used in medical imaging and industrial inspection, typically employ one-dimensional or two-dimensional array arrangements. However, these configurations have significant limitations. One-dimensional transducers can only generate two-dimensional images and cannot provide sufficient information along the thickness direction, thus limiting their ability to perform three-dimensional imaging. While two-dimensional planar transducers can perform three-dimensional imaging, they cannot cover a sufficient solid angle, resulting in highly anisotropic resolution and limiting imaging sensitivity. The development of three-dimensional ultrasound transducer technology has solved these problems, providing a spatial solid angle and a wider imaging field of view that is unattainable with traditional equipment. However, the traditional method of constructing a three-dimensional array by spatially arranging multiple piezoelectric transducer units inevitably results in large gaps and performance differences among transducer units, limiting the effective imaging area and imaging quality, and also posing significant challenges to manufacturing. Currently, a feasible process for manufacturing large-area continuous three-dimensional ultrasound transducers has not yet been developed. Summary of the Invention

[0004] This invention introduces a method for manufacturing a three-dimensional ultrasonic transducer. Utilizing an innovative processing flow, this invention enables the three-dimensional forming of transducer wafers from a planar surface to a spherical surface, while ensuring high structural strength. This invention effectively overcomes the problems of traditional transducers, such as limited unit quantity, low fill rate, high processing complexity, and high cost.

[0005] The manufacturing method of the three-dimensional ultrasonic transducer of the present invention includes the following steps:

[0006] 1) Selection and processing of piezoelectric ceramic wafers:

[0007] Provide piezoelectric ceramic wafers, set the thickness of the piezoelectric ceramic wafers according to the wavelength corresponding to the center frequency, and pre-grind the piezoelectric ceramic wafers to a thickness greater than the set thickness;

[0008] 2) Piezoelectric ceramic wafer cutting:

[0009] The front side of the piezoelectric ceramic wafer is cut to form a ceramic pillar grid structure. The ceramic pillar grid structure includes multiple two-dimensionally distributed ceramic pillars. The cutting depth is a portion of the piezoelectric ceramic wafer, that is, the cutting does not penetrate the back side of the piezoelectric ceramic wafer. The uncut portion is retained as a back-side connecting bridge to maintain overall connectivity and structural strength.

[0010] 3) Front-side potting and double-sided grinding:

[0011] At a set temperature, adhesive is injected into the gaps of the ceramic pillar grid structure on the front side of the piezoelectric ceramic wafer, and then degassed using vacuum or low pressure before curing. The remaining cured adhesive on the front side of the piezoelectric ceramic wafer is removed by grinding to ensure that the front side of the piezoelectric ceramic wafer is fully exposed. Then, the back side of the piezoelectric ceramic wafer is ground to remove the back side connecting bridges left in step 2). The remaining thickness of the piezoelectric ceramic wafer after grinding is still greater than the set thickness of the piezoelectric ceramic wafer in step 1), thus forming a piezoelectric ceramic composite material.

[0012] 4) Preparation of signal ground electrode:

[0013] A layer of highly conductive noble metal is plated on the back of the piezoelectric ceramic composite material to form a signal ground electrode;

[0014] 5) Preparation of matching layer:

[0015] Based on the acoustic impedance matching formula, the material and thickness of each matching layer are determined. The matching material is poured onto the surface of the signal ground electrode, cured, and then polished to form one or more matching layers, thereby improving the acoustic wave transmission efficiency from the piezoelectric ceramic composite material to the imaging area medium.

[0016] 6) Frontal cutting:

[0017] The front side of the piezoelectric ceramic composite material with the matching layer is cut to form a stress-relieving grid; the side length of the stress-relieving grid is greater than the side length of the ceramic column grid structure formed in step 2); the front side is cut to a part of the piezoelectric ceramic composite material, that is, the cut does not penetrate the back side of the piezoelectric ceramic composite material; the part that is not cut and is retained maintains the overall connectivity and structural integrity, in preparation for three-dimensional molding.

[0018] 7) Three-dimensional molding:

[0019] The piezoelectric ceramic composite material with a matching layer formed after the stress relief mesh is formed on the front is preheated, and then three-dimensionally die-cast under controlled temperature and pressure to obtain a three-dimensional piezoelectric ceramic composite material; during this process, the gap of the stress relief mesh will increase, releasing the stress generated during the three-dimensional molding process;

[0020] 8) Front-side potting and filling:

[0021] The adhesive is poured into the gaps of the stress-relieving mesh of the three-dimensional piezoelectric ceramic composite material and cured after degassing using vacuum or low pressure.

[0022] 9) Frontal ball milling:

[0023] The adhesive that has been filled and cured on the surface of the stress-relieving mesh is ball-milled; during this process, the thickness of the piezoelectric ceramic wafer is milled to the thickness designed in step 1).

[0024] 10) Signal electrode fabrication:

[0025] A layer of a highly conductive noble metal is plated on the front side of the three-dimensional piezoelectric ceramic composite material after front-side potting and ball milling to form a signal electrode;

[0026] 11) Assembly:

[0027] A three-dimensional piezoelectric ceramic composite material with signal electrodes is mounted on the surface of a three-dimensional mold, or multiple three-dimensional piezoelectric ceramic composite materials with signal electrodes are fixed on the surface of a three-dimensional mold at a set position to form a three-dimensional piezoelectric ceramic composite material with a set surface structure.

[0028] 12) Array element segmentation:

[0029] Array elements are segmented on the front side of a three-dimensional piezoelectric ceramic composite material with a defined surface structure. CNC machine tools are used to segment array elements of arbitrary shape and spatial distribution. The piezoelectric ceramic composite material is not cut through during the cutting process to ensure the overall structural strength.

[0030] 13) Electrode wiring:

[0031] The signal ground electrodes are connected as a whole and led out through a single lead wire. The signal electrode of each array element is a single electrode and is led out through a single lead wire.

[0032] 14) Three-dimensional mold disassembly:

[0033] Remove the three-dimensional mold used in step 11) to assemble the three-dimensional piezoelectric ceramic composite material with the set surface structure to obtain the three-dimensional ultrasonic transducer.

[0034] In step 1), the piezoelectric ceramic wafer possesses high piezoelectric coefficient and mechanical strength, and is made of lead zirconium titanate (PZT). The piezoelectric ceramic wafer is pre-ground to a thickness greater than a predetermined value, i.e., reserved during the grinding process for subsequent fine machining and surface treatment, ensuring structural uniformity and performance consistency; the pre-ground thickness is 0.1~0.5 mm greater than the predetermined value for subsequent fine machining. The relationship between the thickness of the piezoelectric ceramic wafer and the center frequency and velocity of sound in ultrasonic imaging satisfies the following equation:

[0035]

[0036] in, It is the center frequency of ultrasonic imaging of piezoelectric ceramic wafers. It is the speed at which sound waves propagate in a piezoelectric ceramic wafer. It refers to the thickness of the piezoelectric ceramic wafer.

[0037] In step 2), the front side of the piezoelectric ceramic wafer is cut into a ceramic column grid structure using laser cutting or wafer cutting technology, with the grid side length being 0.2~0.4 mm.

[0038] In step 3), epoxy resin is used as the adhesive; curing is achieved by natural air drying or baking at 40-60 °C for 4-5 hours. The piezoelectric ceramic composite material formed by the ceramic column mesh and the cured adhesive exhibits superior piezoelectric properties. Residual cured adhesive on the front side and the connecting bridges on the back side are removed by grinding to ensure a smooth surface on the piezoelectric ceramic wafer.

[0039] In step 4), gold or silver is used as the noble metal with good conductivity. Since gold powder has poor adhesion, a nickel-chromium alloy layer is first plated before gold plating to ensure successful gold plating. The thickness of the noble metal is 80-120 nm. This step ensures the continuity and uniformity of the electrode, providing a foundation for stable ultrasonic signal transmission and reception. The noble metal is plated on the surface of the piezoelectric ceramic composite material using plasma sputtering.

[0040] In step 5), the matching material uses epoxy resin and tungsten powder. Based on the acoustic impedance matching method, the ratio and type of epoxy resin adhesive, as well as the concentration of metal particles added to the adhesive, are set to adjust the sound velocity and density of the matching layer. Each matching layer is ground smooth after pouring to minimize energy loss during sound wave propagation. Acoustic impedance The calculation formula is:

[0041]

[0042] Where ρ is the material density and V is the velocity of sound. By selecting appropriate materials and thicknesses, a gradual transition in acoustic impedance is achieved, thereby minimizing energy loss. Multiple matching layers are matched from the inside out according to the velocity of sound, from high to low.

[0043] In step 6), the front side of the piezoelectric ceramic composite material with the matching layer is cut into multiple grids using laser cutting or mechanical cutting technology. The side length of the stress-relieving grids formed by cutting is 0.6~1.2 mm; the preheating temperature is 70~85 ℃.

[0044] In step 7), curing is performed by natural air drying.

[0045] In step 8), epoxy resin is used to fill the gaps in the stress-relieving mesh of the three-dimensional piezoelectric ceramic composite material.

[0046] In step 9), grinding is used to remove excess adhesive and reserved thickness from the surface of the stress relief mesh, ensuring that the surface of the three-dimensional piezoelectric ceramic composite material is flat and the thickness meets the design requirements.

[0047] In step 11), the three-dimensional mold is a spherical mold that can be detached from the inside, and multiple pieces of three-dimensional piezoelectric ceramic composite material with signal electrodes are spliced ​​together to form part of a three-dimensional curved surface.

[0048] In step 12), a five-axis machine tool is used to divide the actual array elements. The five-axis machine tool moves along the front of the three-dimensional piezoelectric ceramic composite material with a set surface structure according to the division curve.

[0049] Furthermore, it also includes the preparation of a damping layer:

[0050] Acoustic damping material is infused onto the front of a three-dimensional piezoelectric ceramic composite material with a defined surface structure, forming a damping layer around the surface of the signal electrode to improve the ultrasonic signal attenuation rate and increase bandwidth; this step is not required for applications with higher resonance efficiency. The acoustic damping material is a mixture of epoxy resin adhesive and high-density metal powder.

[0051] Advantages of this invention:

[0052] (1) Through special processing design, the three-dimensional forming of piezoelectric ceramic composite material (from plane to sphere) was realized while maintaining high structural strength.

[0053] (2) Three-dimensional transducers can overcome the limitation of traditional transducers in a certain direction with a limited field of view, greatly improve spatial resolution, and are suitable for high-resolution large field of view three-dimensional imaging. Attached Figure Description

[0054] Figure 1This is a flowchart of the processing method for the three-dimensional ultrasonic transducer of the present invention. Detailed Implementation

[0055] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0056] like Figure 1 As shown, the fabrication method of the three-dimensional integrated ultrasonic transducer in this embodiment includes the following steps:

[0057] 1) Selection and processing of piezoelectric ceramic wafers:

[0058] A piezoelectric ceramic wafer is provided. Based on a center frequency of 1 MHz, the thickness of the piezoelectric ceramic wafer is set to 1.3 mm. The piezoelectric ceramic wafer is pre-ground to a thickness 0.18 mm greater than the set thickness. Figure 1 As shown in (a);

[0059] 2) Piezoelectric ceramic wafer cutting:

[0060] The front side of the piezoelectric ceramic wafer is cut to form a ceramic pillar grid structure with a cutting accuracy of ±0.1 mm. The ceramic pillar grid structure consists of multiple two-dimensionally distributed ceramic pillars with a grid size of 0.3 mm × 0.3 mm. The cutting depth is only a portion of the piezoelectric ceramic wafer, meaning the cut does not penetrate the back side of the wafer. The uncut portion serves as a back-side connecting bridge to maintain overall connectivity and structural strength. Figure 1 As shown in (b);

[0061] 3) Front-side potting and double-sided grinding:

[0062] At a set temperature, adhesive is poured into the ceramic pillar grid structure gaps on the front side of the piezoelectric ceramic wafer. The temperature during the pouring process is controlled at 80°C to ensure sufficient flow and uniform distribution of the epoxy resin. After degassing using a vacuum machine, it is then naturally air-dried for 24 hours to cure. The remaining cured adhesive on the front side of the piezoelectric ceramic wafer is removed by grinding to ensure complete exposure of the front side. Then, the back side of the piezoelectric ceramic wafer is ground to remove the back-side connecting bridges left in step 2). The remaining thickness of the ground piezoelectric ceramic wafer is still 0.1 mm greater than the set thickness of the piezoelectric ceramic wafer in step 1), forming a piezoelectric ceramic composite material, such as... Figure 1 As shown in (c);

[0063] 4) Preparation of signal ground electrode:

[0064] A 100 nm thick layer of gold is deposited on the surface of the piezoelectric ceramic composite material to form a signal ground electrode, such as... Figure 1 As shown in (d);

[0065] 5) Preparation of matching layer:

[0066] According to the acoustic impedance matching formula Where ρ is the density of the material and ρ is the velocity of sound, the thickness and material of each matching layer are determined. In this embodiment, the first matching layer is a 0.6 mm thick epoxy resin with added tungsten powder, and the second matching layer is a 0.5 mm thick epoxy resin, aiming to minimize sound wave reflection from the piezoelectric ceramic wafer to human tissue. Matching materials are poured onto the surface of the signal ground electrode, cured, and then polished smooth to form the first and second matching layers, improving the sound wave transmission efficiency from the piezoelectric ceramic wafer to the imaging area medium. Figure 1 As shown in (e);

[0067] 6) Frontal cutting:

[0068] The front side of the piezoelectric ceramic composite material with the matching layer is cut to form a stress-relieving mesh; 2×2 ceramic pillar mesh structures are grouped and segmented; the front side is cut to a portion of the piezoelectric ceramic composite material, i.e., the cut does not penetrate the back side of the piezoelectric ceramic composite material; the uncut portions maintain overall connectivity and structural integrity, preparing for 3D molding, such as... Figure 1 As shown in (f);

[0069] 7) Three-dimensional molding:

[0070] The piezoelectric ceramic composite material with a matching layer formed after the stress-relieving mesh is formed on the front side is preheated to approximately 80 °C. Then, it is three-dimensionally die-cast under controlled temperature and pressure (approximately 80 °C, pressure 50–300 N) to obtain the three-dimensional piezoelectric ceramic composite material. During this process, the gaps in the stress-relieving mesh increase, releasing the stress generated during the three-dimensional forming process, such as… Figure 1 As shown in (g);

[0071] 8) Front-side potting and filling:

[0072] The adhesive is poured into the gaps of the stress-relieving mesh of the three-dimensional piezoelectric ceramic composite material, and then degassed using vacuum or low-pressure methods before curing. Figure 1 As shown in (h);

[0073] 9) Frontal ball milling:

[0074] The adhesive, after being filled and cured on the surface of the stress-relieving mesh, is ball-milled; during this process, the thickness of the piezoelectric ceramic wafer is ground to the thickness of 1.3 mm designed in step 1). Figure 1 As shown in (i);

[0075] 10) Signal electrode fabrication:

[0076] A 100 nm thick gold layer was deposited on the front side of the three-dimensional piezoelectric ceramic composite material after front-side potting and ball milling to form a signal electrode, such as... Figure 1 As shown in (j);

[0077] 11) Assembly:

[0078] Multiple pieces of three-dimensional piezoelectric ceramic composite material with signal electrodes are fixed to the surface of a three-dimensional mold at predetermined positions to form a three-dimensional piezoelectric ceramic composite material with signal electrodes; the surface structure is set to be a partial sphere, with the partial sphere occupying 3 / 5 of the entire sphere, such as... Figure 1 As shown in (k);

[0079] 12) Array element segmentation:

[0080] Array elements are segmented on the front side of a three-dimensional piezoelectric ceramic composite material with a spherical surface structure. Arbitrary array element positions and shapes are achieved by CNC machine tool cutting and dividing the material. The piezoelectric ceramic composite material is not cut through during the cutting process to ensure overall structural strength. Figure 1 As shown in (l);

[0081] 13) Electrode wiring:

[0082] The signal ground electrodes are connected as a single unit as the negative electrode and led out through a single lead. Each array element's signal electrode serves as a positive electrode and is led out through a separate lead. Figure 1 As shown in (m); a through hole is opened from the surface of the signal electrode downwards, extending to the signal ground electrode. The wall of the through hole is gold-plated to guide the internal signal ground electrode to the outside. An annular groove is opened outside the through hole of the signal ground electrode. The annular groove is located outside the through hole of the ground electrode, and the depth of the annular groove extends to the lower surface of the signal electrode, so that the signal electrode is insulated from the ground electrode. The annular groove acts as an insulating layer to isolate the internal signal ground electrode from the signal electrode on the outer surface, ensuring that both positive and negative signals can be led from the outer surface of the sphere.

[0083] 14) Damping layer preparation:

[0084] A 10 mm thick mixture of epoxy resin adhesive and high-density metal powder is injected into the outer surface of a three-dimensional piezoelectric ceramic composite material with a spherical surface structure after the positive and negative electrodes are led out, forming a damping layer on the surface of the signal electrode.

[0085] 15) Disassembly of the 3D mold:

[0086] The spherical three-dimensional mold was removed from the inside to obtain a three-dimensional ultrasonic transducer, such as... Figure 1 As shown in (n).

[0087] Finally, it should be noted that the purpose of disclosing the embodiments is to help further understand the present invention. However, those skilled in the art will understand that various substitutions and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the present invention should not be limited to the content disclosed in the embodiments, and the scope of protection of the present invention is defined by the claims.

Claims

1. A method for manufacturing a three-dimensional ultrasonic transducer, characterized in that, The manufacturing method includes the following steps: 1) Selection and processing of piezoelectric ceramic wafers: Provide piezoelectric ceramic wafers, set the thickness of the piezoelectric ceramic wafers according to the wavelength corresponding to the center frequency, and pre-grind the piezoelectric ceramic wafers to a thickness greater than the set thickness; 2) Piezoelectric ceramic wafer cutting: The front side of the piezoelectric ceramic wafer is cut to form a ceramic pillar grid structure. The ceramic pillar grid structure includes multiple two-dimensionally distributed ceramic pillars. The cutting depth is a portion of the piezoelectric ceramic wafer, that is, the cutting does not penetrate the back side of the piezoelectric ceramic wafer. The uncut portion is retained as a back-side connecting bridge to maintain overall connectivity and structural strength. 3) Front-side potting and double-sided grinding: At a set temperature, adhesive is injected into the gaps of the ceramic pillar grid structure on the front side of the piezoelectric ceramic wafer, and then degassed using vacuum or low pressure before curing. The remaining cured adhesive on the front side of the piezoelectric ceramic wafer is removed by grinding to ensure that the front side of the piezoelectric ceramic wafer is fully exposed. Then, the back side of the piezoelectric ceramic wafer is ground to remove the back side connecting bridges left in step 2). The remaining thickness of the piezoelectric ceramic wafer after grinding is still greater than the set thickness of the piezoelectric ceramic wafer in step 1), thus forming a piezoelectric ceramic composite material. 4) Preparation of signal ground electrode: A layer of highly conductive noble metal is plated on the back of the piezoelectric ceramic composite material to form a signal ground electrode; 5) Preparation of matching layer: Based on the acoustic impedance matching formula, the material and thickness of each matching layer are determined. The matching material is poured onto the surface of the signal ground electrode, cured, and then polished to form one or more matching layers, thereby improving the acoustic wave transmission efficiency from the piezoelectric ceramic composite material to the imaging area medium. 6) Frontal cutting: The front side of the piezoelectric ceramic composite material with the matching layer is cut to form a stress-relieving grid; the side length of the stress-relieving grid is greater than the side length of the ceramic column grid structure formed in step 2); the front side is cut to a part of the piezoelectric ceramic composite material, that is, the cut does not penetrate the back side of the piezoelectric ceramic composite material; the part that is not cut and is retained maintains the overall connectivity and structural integrity, in preparation for three-dimensional molding. 7) Three-dimensional molding: The piezoelectric ceramic composite material with a matching layer formed after the stress relief mesh is formed on the front is preheated, and then three-dimensionally die-cast under controlled temperature and pressure to obtain a three-dimensional piezoelectric ceramic composite material; during this process, the gap of the stress relief mesh will increase, releasing the stress generated during the three-dimensional molding process; 8) Front-side potting and filling: The adhesive is poured into the gaps of the stress-relieving mesh of the three-dimensional piezoelectric ceramic composite material and cured after degassing using vacuum or low pressure. 9) Frontal ball milling: The adhesive that has been filled and cured on the surface of the stress-relieving mesh is ball-milled; during this process, the thickness of the piezoelectric ceramic wafer is milled to the thickness designed in step 1). 10) Signal electrode fabrication: A layer of a highly conductive noble metal is plated on the front side of the three-dimensional piezoelectric ceramic composite material after front-side potting and ball milling to form a signal electrode; 11) Assembly: A three-dimensional piezoelectric ceramic composite material with signal electrodes is mounted on the surface of a three-dimensional mold, or multiple three-dimensional piezoelectric ceramic composite materials with signal electrodes are fixed on the surface of a three-dimensional mold at a set position to form a three-dimensional piezoelectric ceramic composite material with a set surface structure. 12) Array element segmentation: Array elements are segmented on the front side of a three-dimensional piezoelectric ceramic composite material with a defined surface structure. CNC machine tools are used to segment array elements of arbitrary shape and spatial distribution. The piezoelectric ceramic composite material is not cut through during the cutting process to ensure the overall structural strength. 13) Electrode wiring: The signal ground electrodes are connected as a whole and led out through a single lead wire. The signal electrode of each array element is a single electrode and is led out through a single lead wire. 14) Three-dimensional mold disassembly: Remove the three-dimensional mold used in step 11) to assemble the three-dimensional piezoelectric ceramic composite material with the set surface structure to obtain the three-dimensional ultrasonic transducer.

2. The manufacturing method as described in claim 1, characterized in that, In step 1), the piezoelectric ceramic wafer is a lead zirconium titanate wafer; it is pre-ground to a thickness greater than the set value of 0.1~0.5 mm.

3. The manufacturing method as described in claim 1, characterized in that, In step 2), the front side of the piezoelectric ceramic wafer is cut into a ceramic column grid structure using laser cutting or wafer cutting technology, with the grid side length being 0.2~0.4 mm.

4. The manufacturing method as described in claim 1, characterized in that, In step 3), the adhesive used is epoxy resin; curing is carried out by natural air drying or baking at 40~60 ℃ for 4~5 hours.

5. The manufacturing method as described in claim 1, characterized in that, In step 4), the noble metal with good conductivity is gold or silver; the thickness of the noble metal is 80~120 nm.

6. The manufacturing method as described in claim 1, characterized in that, In step 6), the front side of the piezoelectric ceramic composite material with the matching layer is cut into multiple grids using laser cutting or mechanical cutting technology, and the side length of the stress relief grids formed by cutting is 0.6~1.2 mm; in step 7), the preheating temperature is 70~85 ℃.

7. The manufacturing method as described in claim 1, characterized in that, In step 8), epoxy resin is used to fill the gaps in the stress-relieving mesh of the three-dimensional piezoelectric ceramic composite material.

8. The manufacturing method as described in claim 1, characterized in that, In step 11), the three-dimensional mold is a spherical mold that can be detached from the inside, and multiple pieces of three-dimensional piezoelectric ceramic composite material with signal electrodes are spliced ​​together to form part of a three-dimensional curved surface.

9. The manufacturing method as described in claim 1, characterized in that, In step 12), a five-axis machine tool is used to divide the actual array elements. The five-axis machine tool moves along the front of the three-dimensional piezoelectric ceramic composite material with a set surface structure according to the division curve.

10. The manufacturing method as described in claim 1, characterized in that, It also includes preparing a damping layer after electrode wiring and before disassembly of the three-dimensional mold: injecting acoustic damping material into the front of a three-dimensional piezoelectric ceramic composite material with a set surface structure to form a damping layer that wraps around the surface of the signal electrode, thereby improving the ultrasonic signal attenuation rate and increasing bandwidth.

Images