Ultrasonic transducer and manufacturing method therefor

Abstract

The present application provides an ultrasonic transducer and a manufacturing method therefor. The ultrasonic transducer comprises a backing layer, a piezoelectric layer, and a matching layer which are stacked; the matching layer comprises a first flexible circuit board, wherein the first flexible circuit board comprises flexible conductive substrates and flexible dielectric layers which are alternately stacked. Because the flexible conductive substrates and the flexible dielectric layers have relatively large strain, the matching layer consequently has relatively large strain. This results in the ultrasonic transducer having relatively large strain, which allows the ultrasonic transducer to be applied to skin surfaces of various shapes.

Description

Ultrasonic transducer and its manufacturing method

[0001] Cross-reference to related applications

[0002] This application claims priority to Chinese Patent Application No. 202410793879.3, filed on June 19, 2024, entitled "Ultrasonic Transducer and Method of Manufacturing Thereof", the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of ultrasonic imaging technology, and more specifically, to an ultrasonic transducer and its manufacturing method. Background Technology

[0004] Medical ultrasound imaging technology primarily involves using an ultrasound transducer to emit ultrasound waves into the human body and perform linear, fan-shaped, or other forms of scanning. When encountering the interface between two tissues with different acoustic impedances, the ultrasound waves are reflected back and received by the transducer. After signal amplification and processing, the images are displayed on a screen, forming a tomographic image of the human body, called an ultrasound image, for clinical diagnostic purposes. Multiple consecutive ultrasound images displayed on the screen allow for observation of dynamic organ activity.

[0005] Typically, ultrasonic transducers consist of a piezoelectric layer, a matching layer, and a backing layer. Existing ultrasonic transducers exhibit low strain, limiting their applicability to skin surfaces of various shapes. Summary of the Invention

[0006] This application addresses the shortcomings of existing methods by proposing an ultrasonic transducer and its manufacturing method to solve the technical problem that ultrasonic transducers have small strain and cannot be used on skin surfaces of different shapes.

[0007] In a first aspect, embodiments of this application provide an ultrasonic transducer, including a stacked backing layer, a piezoelectric layer, and a matching layer; the matching layer includes a first flexible circuit board, which includes alternately stacked flexible conductive substrates and flexible dielectric layers.

[0008] Optionally, at least one of the number of layers of the first flexible circuit board and the acoustic impedance value of the matching layer is matched with the operating frequency of the ultrasonic transducer.

[0009] Optionally, the flexible conductive substrate includes a flexible substrate and a metal film layer covering both sides of the flexible substrate;

[0010] The thickness ratio of the metal film layer to the flexible substrate is matched with the operating frequency.

[0011] Optionally, the matching layer further includes a second flexible circuit board; the second flexible circuit board is located between the first flexible circuit board and the piezoelectric layer;

[0012] The ultrasonic transducer further includes a third flexible circuit board; the third flexible circuit board is located between the backing layer and the piezoelectric layer;

[0013] The piezoelectric layer includes: a first electrode and a second electrode; the second electrode is close to and connected to the second flexible circuit board, and the first electrode is close to and connected to the third flexible circuit board.

[0014] Optionally, the thickness of the backing layer is matched to the operating frequency of the ultrasonic transducer.

[0015] Optionally, the backing layer includes a base and rods inserted into the base; a plurality of the rods are arranged in the base according to a regular polygonal rule.

[0016] Optionally, the ultrasonic transducer includes at least one of the following:

[0017] The plurality of the aforementioned rods are arranged in the base according to a regular hexahedral rule;

[0018] The material of the rod includes metal or elastic material.

[0019] Optionally, the ultrasonic transducer includes at least one of the following:

[0020] The thickness of the matching layer includes one-quarter wavelength of the transmitted ultrasonic wave;

[0021] The first-order vibration of the piezoelectric layer is longitudinal vibration.

[0022] Secondly, embodiments of this application provide a method for manufacturing an ultrasonic transducer, used to manufacture any of the ultrasonic transducers described above, comprising:

[0023] Manufacturing piezoelectric layers;

[0024] A matching layer is fabricated, and a flexible dielectric layer and a flexible conductive substrate are alternately stacked to obtain a first flexible circuit board; the first flexible circuit board is then connected to a piezoelectric layer.

[0025] A backing layer is manufactured, and the backing layer and the piezoelectric layer are coupled together using conductive adhesive.

[0026] Optionally, connecting the first flexible circuit board 31 to the piezoelectric layer 2 includes:

[0027] A third flexible circuit board is manufactured by connecting the first electrode of the piezoelectric layer to the third flexible circuit board.

[0028] A second flexible circuit board is manufactured, and the second electrode of the piezoelectric layer is connected to the second flexible circuit board.

[0029] The beneficial technical effects of the technical solutions provided in this application include:

[0030] In this embodiment, the matching layer of the ultrasonic transducer includes a first flexible circuit board, which comprises alternately stacked flexible conductive substrates and flexible dielectric layers. Because the flexible conductive substrates and flexible dielectric layers have large strain, the matching layer also has large strain, resulting in a large strain in the ultrasonic transducer, thus enabling it to be adapted to skin surfaces of different shapes.

[0031] Additional aspects and advantages of this application will be set forth in part in the description which follows, and will become apparent from the description or may be learned by practice of this application. Attached Figure Description

[0032] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the following description of the embodiments taken in conjunction with the accompanying drawings, wherein:

[0033] Figure 1 is a structural schematic diagram of an ultrasonic transducer provided in an embodiment of this application;

[0034] Figure 2 is a schematic diagram of the backing layer structure of an ultrasonic transducer provided in an embodiment of this application;

[0035] Figure 3 is a schematic diagram of the structure of a flexible conductive substrate in an ultrasonic transducer provided in an embodiment of this application;

[0036] Figure 4 is a flowchart illustrating an ultrasonic transducer manufacturing method provided in an embodiment of this application.

[0037] Reference numerals: 1-Backing layer; 11-Substrate; 12-Ring; 2-Piezoelectric layer; 3-Matching layer; 31-First flexible circuit board; 311-Flexible conductive substrate; 3111-Flexible substrate; 3112-Metal film layer; 312-Flexible dielectric layer; 32-Second flexible circuit board; 4-Third flexible circuit board. Detailed Implementation

[0038] The embodiments of this application are described below with reference to the accompanying drawings. It should be understood that the embodiments described below with reference to the accompanying drawings are exemplary descriptions for explaining the technical solutions of the embodiments of this application, and do not constitute a limitation on the technical solutions of the embodiments of this application.

[0039] Those skilled in the art will understand that, unless specifically stated otherwise, the terms "described" and "the" as used herein may also include plural forms. It should be further understood that the term "comprising" as used in the specification of this application means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude other features, information, data, steps, operations, elements, components, and / or combinations thereof supported by the art. The term "and / or" as used herein refers to at least one of the items defined by the term; for example, "A and / or B" can be implemented as "A," or as "B," or as "A and B."

[0040] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0041] Medical ultrasound imaging technology primarily involves using an ultrasound transducer to emit ultrasound waves into the human body and perform linear, fan-shaped, or other forms of scanning. When encountering the interface between two tissues with different acoustic impedances, the ultrasound waves are reflected back and received by the transducer. After signal amplification and processing, the images are displayed on a screen, forming a tomographic image of the human body, called an ultrasound image, for clinical diagnostic purposes. Multiple consecutive ultrasound images displayed on the screen allow for observation of dynamic organ activity.

[0042] Typically, ultrasonic transducers consist of a piezoelectric layer, a matching layer, and a backing layer. Existing ultrasonic transducers exhibit low strain, limiting their applicability to skin surfaces of various shapes.

[0043] The technical solution of this application and how it solves the above-mentioned technical problems are described in detail below with specific embodiments. It should be noted that the following embodiments can be referenced, borrowed, or combined with each other, and the same terms, similar features, and similar implementation steps in different embodiments will not be described again.

[0044] This application provides an ultrasonic transducer, as shown in Figures 1-3. The ultrasonic transducer includes a backing layer 1, a piezoelectric layer 2, and a matching layer 3 stacked together. The matching layer 3 includes a first flexible circuit board 31, which includes an alternately stacked flexible conductive substrate 311 and a flexible dielectric layer 312.

[0045] In this embodiment, the matching layer 3 of the ultrasonic transducer includes a first flexible circuit board 31, which includes alternately stacked flexible conductive substrates 311 and flexible dielectric layers 312. Because the flexible conductive substrates 311 and flexible dielectric layers 312 have large strain, the matching layer 3 also has large strain, resulting in a large strain in the ultrasonic transducer, thus enabling it to be adapted to skin surfaces of different shapes.

[0046] Optionally, in this embodiment, the flexible conductive substrate 311 includes a copper-clad substrate, the flexible dielectric layer 312 is made of polyimide, and the piezoelectric layer 2 is made of 1-3 flexible composite materials.

[0047] Optionally, in one embodiment of this application, as shown in FIG1, at least one of the number of layers of the first flexible circuit board 31 and the acoustic impedance value of the matching layer 3 is matched with the operating frequency of the ultrasonic transducer.

[0048] In this embodiment, the matching layer 3 is formed by laminating multiple layers of first flexible circuit boards 31. At least one of the number of layers of the first flexible circuit boards 31 and the acoustic impedance value of the matching layer 3 is matched with the operating frequency of the ultrasonic transducer. When it is necessary to perform ultrasonic detection on organs or tissues at any depth, the target operating frequency of the ultrasonic transducer can be determined according to the target detection depth. Then, at least one of the target number of layers of the first flexible circuit boards 31 and the target acoustic impedance value of the matching layer 3 can be determined according to the above matching relationship. This enables the ultrasonic transducer using this embodiment to be adapted to ultrasonic detection at a wider range of depths, including the ability to perform high-definition imaging of deep organs, and improves the deep imaging capability of the ultrasonic transducer.

[0049] Optionally, in one embodiment of this application, as shown in FIG3, the flexible conductive substrate 311 includes a flexible substrate 3111 and a metal film layer 3112 covering both sides of the flexible substrate 3111.

[0050] The thickness ratio of the metal film layer 3112 to the flexible substrate 3111 is matched with the operating frequency of the ultrasonic transducer.

[0051] In this embodiment, by changing the thickness ratio of the metal film layer 3112 to the flexible substrate 3111, the acoustic impedance value of the matching layer 3 can be adjusted so that the acoustic impedance value of the matching layer 3 matches the operating frequency of the ultrasonic transducer. When ultrasonic detection of organs or tissues at any depth is required, the target operating frequency of the ultrasonic transducer can be determined according to the depth of the target tissue or organ. Then, the thickness ratio of the metal film layer 3112 to the flexible substrate 3111 can be determined according to the above matching relationship, thereby determining the acoustic impedance value of the matching layer 3. This allows the ultrasonic transducer using this embodiment to be adapted to ultrasonic detection at a wider range of depths, including high-definition imaging of deep organs, and improves the deep imaging capability of the ultrasonic transducer. In Figure 3, multiple rectangular blocks of metal film layers 3112 arranged at intervals represent patterned circuit traces. The material of the metal film layer 3112 includes copper, etc., and the material of the flexible substrate 3111 includes polyimide, etc.

[0052] Optionally, in the embodiments of this application, the flexible conductive substrate 311 is widely used as a substrate for electrical packaging. In this application, the widely used flexible conductive substrate 311 is selected. The acoustic impedance value of the matching layer 3 is adjusted by the thickness ratio of the metal film layer 3112 and the flexible substrate 3111 in the flexible conductive substrate 311, so that the acoustic impedance between the piezoelectric layer 2 and the external object is matched.

[0053] Optionally, in one embodiment of this application, as shown in FIG1, the matching layer 3 further includes a second flexible circuit board 32; the second flexible circuit board 32 is located between the first flexible circuit board 31 and the piezoelectric layer 2.

[0054] The ultrasonic transducer also includes a third flexible circuit board 4; the third flexible circuit board 4 is located between the backing layer 1 and the piezoelectric layer 2.

[0055] The piezoelectric layer 2 includes a first electrode and a second electrode; the second electrode is close to and connected to the second flexible circuit board 32, and the first electrode is close to and connected to the third flexible circuit board 4.

[0056] In this embodiment, the piezoelectric layer 2 is composed of multiple independently operating ultrasonic array elements. The piezoelectric layer 2 includes a first electrode disposed near the backing layer 1 and a second electrode disposed near the first flexible circuit board 31. The first electrode can be a signal electrode, and the second electrode can be a ground electrode. The first electrodes of the piezoelectric layer 2 array elements are separated. Multiple electrode units with the same spacing as the array elements are fabricated on the third flexible circuit board 4. The electrode units on the third flexible circuit board 4 are corresponding one-to-one with the array elements of the piezoelectric layer 2 and bonded together, thereby electrically connecting the first electrode on the array element to the electrode on the third flexible circuit board 4, thus leading out the first electrode. The second electrodes of all the array elements of the piezoelectric layer 2 are connected together, and the second electrode is connected to the second flexible circuit board 32, thereby leading out the second electrode on the array element.

[0057] Optionally, in some embodiments, the piezoelectric layer 2 includes a first electrode surface disposed near the backing layer 1 and a second electrode surface disposed near the first flexible circuit board 31. The first and second electrode surfaces each have electrodes. The electrodes of the first electrode surface are cut to form multiple array elements, and the second electrodes of the second electrode surface are spaced apart at the same spacing as the array elements of the first electrode surface to form multiple electrode units. The second flexible circuit board 32 is connected to the second electrode of the piezoelectric layer 2, and the third flexible circuit board 4 is connected to the first electrode of the first electrode surface of the piezoelectric layer 2, thereby leading out the array elements of the piezoelectric layer 2. A conductive material is disposed on one or both ends of the piezoelectric layer 2 along the extending direction of the gaps formed by the array element divisions to form a conductive structure. The conductive structure is used to connect the multiple electrode units of the piezoelectric layer 2. The conductive material includes, but is not limited to, conductive copper foil and conductive adhesive.

[0058] Optionally, in one embodiment of this application, as shown in FIG1, the thickness of the backing layer 1 is matched with the operating frequency of the ultrasonic transducer.

[0059] Optionally, the ultrasonic transducer includes a stacked backing layer 1, a piezoelectric layer 2, and a matching layer 3. The piezoelectric layer 2 emits ultrasonic waves, the matching layer 3 is used to match the acoustic impedance between the piezoelectric layer 2 and an external object, and the backing layer 1 is used to absorb ultrasonic waves propagating towards the backing layer 1. When the ultrasonic transducer is working, the power is turned on, the piezoelectric crystal in the piezoelectric layer 2 deforms, generating mechanical vibration, which propagates out in the form of ultrasonic waves, thereby realizing the conversion of electrical energy into mechanical energy. The ultrasonic waves generated by the piezoelectric layer 2 propagate to both the backing layer 1 and the matching layer 3 simultaneously. The ultrasonic waves propagating to the backing layer 1 are reflected and affect the ultrasonic waves propagating to the matching layer 3, thus affecting the quality of ultrasonic imaging.

[0060] In this embodiment, the thickness of the backing layer 1 is matched with the operating frequency of the ultrasonic transducer. By adjusting the thickness of the backing layer 1, its absorption capacity for ultrasonic waves is adjusted. Based on the location of the target tissue or organ being detected, the target operating frequency of the ultrasonic transducer is determined. Then, according to the aforementioned matching relationship, the thickness of the backing layer 1 is determined, thereby enabling the backing layer 1 to have a greater absorption capacity for ultrasonic waves. This reduces the influence of ultrasonic waves propagating from the piezoelectric layer 2 to the backing layer 1 on the ultrasonic waves propagating from the matching layer 3, allowing a large amount of ultrasonic waves propagating from the piezoelectric layer 2 to the backing layer 1 to propagate out, thus improving the quality of ultrasonic imaging and enabling the ultrasonic transducer to perform high-definition imaging of deep organs.

[0061] Optionally, in one embodiment of this application, as shown in FIG2, the backing layer 1 includes a base 11 and rods 12 inserted in the base 11; the plurality of rods 12 are arranged in the base 11 according to the regular polygonal rule.

[0062] In this embodiment, the multiple rods 12 of the backing layer 1 are arranged in the substrate 11 according to the regular polygonal rule, so that the backing layer 1 has a large acoustic attenuation capability. Thus, the backing layer 1 can better absorb the ultrasonic waves propagating from the piezoelectric layer 2 to the backing layer 1, and the ultrasonic waves propagating to the backing layer 1 are reflected less, reducing the impact on the ultrasonic waves propagating to the matching layer 3, thereby improving the ultrasonic imaging quality.

[0063] Optionally, in one embodiment of this application, as shown in Figures 1-2, a plurality of rods 12 are arranged in a regular hexahedral pattern in the base 11. The material of the rods 12 includes metal or elastic material.

[0064] In this embodiment, multiple rods 12 are arranged in a regular hexahedral pattern in the substrate 11 to form a hexahedral lattice. The substrate 11 is made of silicone, and the rods 12 are made of metal or elastic material. The rods 12 of the backing layer 1 and the substrate 11 form a phononic crystal structure. This allows the backing layer 1 of this embodiment to have a greater attenuation capability when the thickness of the backing layer is the same as that of a conventional backing layer. This reduces the impact of the ultrasonic waves propagating from the piezoelectric layer 2 to the backing layer 1 on the ultrasonic waves propagating from the matching layer 3, thereby improving the bandwidth and imaging quality of the ultrasonic transducer signal. Furthermore, because the backing layer 1 of this embodiment has a greater attenuation capability than a conventional backing layer, it has a smaller thickness for the same attenuation capability. This results in a smaller ultrasonic transducer volume, which is easier to position and manipulate during operation, thus lowering the operating threshold and making the ultrasonic transducer easier to operate.

[0065] Optionally, in this embodiment, the ultrasonic transducer includes a stacked backing layer 1, a third flexible circuit board 4, a piezoelectric layer 2, and a matching layer 3. The backing layer 1 has a phononic crystal structure composed of rods 12 and a substrate 11. The piezoelectric layer 2 includes an array of 1-3 flexible composite materials. The matching layer 3 includes a first flexible circuit board 31 and a second flexible circuit board 32. The ultrasonic transducer provided in this application uses a variety of flexible materials, giving it greater strain; it can adapt to different skin surfaces, making it suitable for examining different parts of the body and increasing the comprehensiveness of imaging. Moreover, the backing layer 1 has a greater attenuation capacity, effectively reducing the impact of ultrasound waves propagating to the backing layer 1 on ultrasound waves propagating to the matching layer 3, resulting in high imaging quality and providing high-quality imaging for superficial and / or deep tissues. The matching layer 3, including the first flexible circuit board 31 and the second flexible circuit board 32, makes the ultrasonic transducer highly wearable. The ultrasonic transducer provided in this application can be used in fields such as medical imaging, tumor detection, and biomedical research.

[0066] In one specific embodiment of this application, the piezoelectric layer 2 is made of 1-3 flexible composite material, the rod 12 is made of steel, the substrate 11 is made of silicone, the strain of the ultrasonic transducer is not less than 40%, the electromechanical coupling coefficient is not less than 70%, and the bandwidth is not less than 80%.

[0067] Optionally, in one embodiment of this application, as shown in FIG1, the thickness of the matching layer 3 includes a quarter wavelength of the transmitted ultrasonic wave. The first-order vibration of the piezoelectric layer 2 is longitudinal vibration.

[0068] In this embodiment, the matching layer 3 is used to match the acoustic impedance between the piezoelectric layer 2 and an external object. The thickness of the matching layer 3 is set to one-quarter wavelength of the ultrasonic wave transmitted through the matching layer 3, at which point the acoustic impedance value of the matching layer 3 is close to 5 MRayl, which is the ideal acoustic impedance matching value between the piezoelectric layer 2 and water.

[0069] In one specific embodiment of this application, the material of the piezoelectric layer 2 is selected as 1-3PZT epoxy resin composite piezoelectric material, wherein the volume ratio of PZT (lead zirconate titanate) to EPOXY (epoxy acrylate resin) is 25%, which enables the piezoelectric layer 2 to withstand large strain, with an electromechanical coupling coefficient Kt of 0.71 and d33 of 515 PC / N. At this time, the acoustic impedance value of the matching layer 3 is 14.1 MRayl.

[0070] Optionally, in this embodiment, the ultrasonic transducer includes a stacked backing layer 1, a piezoelectric layer 2, and a matching layer 3. The piezoelectric layer 2 is the core component of ultrasonic imaging. The piezoelectric layer 2 consists of a linear array of multiple (32 / 48 / 96 / 128) ultrasonic elements. Each ultrasonic element is used to transmit and receive ultrasonic waves, enabling the ultrasonic transducer to perform B-mode imaging and Doppler imaging of different human organs, such as the carotid artery and heart. In this embodiment, the number of ultrasonic elements and the shape of the ultrasonic transducer can be flexibly adjusted according to actual needs to meet different application environments. The ultrasonic transducer in this embodiment is compatible with wired and wireless data transmission and data processing terminals.

[0071] Based on the same inventive concept, this application provides a method for manufacturing an ultrasonic transducer, used to manufacture the ultrasonic transducer of any of the above embodiments. A flowchart of the method is shown in Figure 4, and the method includes the following steps:

[0072] S101: Manufacturing piezoelectric layer 2.

[0073] S102: Fabricate the matching layer 3, alternately stack the flexible dielectric layer 312 and the flexible conductive substrate 311 to obtain the first flexible circuit board 31; connect the first flexible circuit board 31 to the piezoelectric layer 2.

[0074] S103: Fabricate backing layer 1 and couple backing layer 1 and piezoelectric layer 2 together using conductive adhesive.

[0075] In this embodiment, the manufacturing process of the first flexible circuit board 31 includes: alternatingly stacking a flexible substrate 3111 and a metal film layer 3112 to form a multilayer composite structure; then performing soft etching on the structure to give the metal film layer 3112 a certain roughness; coating a dry film on the pretreated metal film layer 3112 and patterning it by ultraviolet exposure; polymerizing the exposed dry film, removing the unexposed dry film by development, and removing the metal film layer 3112 under the unexposed dry film, finally forming a patterned flexible conductive substrate 311, and laminating the stacked flexible conductive substrates 311 to obtain the first flexible circuit board 31.

[0076] In one specific embodiment of this application, the manufacturing process of the backing layer 1 includes: arranging multiple steel columns with a diameter of 1 mm and a height of 1 mm in a regular hexagonal pattern in a mold, with a spacing of 2 mm between adjacent steel columns; then mixing silicone with an appropriate amount of hardener and filler; pouring the silicone mixture into a mold containing the steel columns, and using vibration or other methods to ensure the silicone mixture is evenly filled and compacted; placing the mold in a constant temperature chamber or other heating equipment and maintaining it at a certain temperature for 5 minutes, such as 80-100 degrees Celsius; when the silicone is completely cured, removing the mold; and further processing and shaping, such as cutting, trimming, and polishing, to obtain the desired shape and size of the backing layer 1.

[0077] In this embodiment, the backing layer 1, piezoelectric layer 2, and matching layer 3 are manufactured separately, without any specific manufacturing order. After the backing layer 1, piezoelectric layer 2, and matching layer 3 are manufactured, the backing layer 1 and piezoelectric layer 2 are coupled together via conductive adhesive, and the matching layer 3 and piezoelectric layer 2 are electrically connected. The conductive adhesive can be Esolder-3022.

[0078] Optionally, in one embodiment of this application, as shown in FIG1, the connection of the first flexible circuit board 31 to the piezoelectric layer 2 in step S102 includes:

[0079] A third flexible circuit board 4 is manufactured, and the first electrode of the piezoelectric layer 2 is connected to the third flexible circuit board 4.

[0080] A second flexible circuit board 32 is manufactured, and the second electrode of the piezoelectric layer 2 is connected to the second flexible circuit board 32.

[0081] In the embodiments of this application, the manufacturing processes of the first flexible circuit board 31, the second flexible circuit board 32 and the third flexible circuit board 4 are the same, and will not be described again here.

[0082] In this embodiment, during the manufacturing of the third flexible circuit board 4, electrode units matching the first electrodes of each ultrasonic element of the piezoelectric layer 2 are reserved on the metal film layer of the third flexible circuit board 4, and the first electrodes of each ultrasonic element of the piezoelectric layer 2 are connected to the corresponding electrode units on the third flexible circuit board 4. During the manufacturing of the second flexible circuit board 32, electrode units matching the ground electrodes of each ultrasonic element of the piezoelectric layer 2 are reserved on the metal film layer of the second flexible circuit board 32, and the second electrodes of each ultrasonic element of the piezoelectric layer 2 are connected to the corresponding electrode units on the second flexible circuit board 32. It should be noted that the second flexible circuit board 32 and the first flexible circuit board 31 can be integrally manufactured.

[0083] By applying the embodiments of this application, at least the following beneficial effects can be achieved:

[0084] In this embodiment, the matching layer 3 of the ultrasonic transducer includes a first flexible circuit board 31, which includes alternately stacked flexible conductive substrates 311 and flexible dielectric layers 312. Because the flexible conductive substrates 311 and flexible dielectric layers 312 have large strain, the matching layer 3 also has large strain, resulting in a large strain in the ultrasonic transducer, thus enabling it to be adapted to skin surfaces of different shapes.

[0085] Those skilled in the art will understand that the steps, measures, and solutions in the various operations, methods, and processes discussed in this application can be alternated, modified, combined, or deleted. Furthermore, other steps, measures, and solutions in the various operations, methods, and processes discussed in this application can also be alternated, modified, rearranged, decomposed, combined, or deleted. Furthermore, steps, measures, and solutions in related technologies that are similar to those disclosed in this application can also be alternated, modified, rearranged, decomposed, combined, or deleted.

[0086] In the description of this application, the terms "center," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate directions or positional relationships based on the exemplary directions or positional relationships shown in the accompanying drawings. They are used to facilitate the description or simplification of the embodiments of this application and are not intended to indicate or imply that the device or component referred to must have a specific orientation or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0087] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0088] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0089] In the description of this specification, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0090] The above description is only a partial implementation of this application. It should be noted that for those skilled in the art, other similar implementation methods based on the technical concept of this application, without departing from the technical concept of this application, also fall within the protection scope of the embodiments of this application.

Claims

1. An ultrasonic transducer, characterized in that, It includes a stacked backing layer, a piezoelectric layer, and a matching layer; the matching layer includes a first flexible circuit board, which includes alternately stacked flexible conductive substrates and flexible dielectric layers.

2. The ultrasonic transducer according to claim 1, characterized in that, At least one of the number of layers of the first flexible circuit board and the acoustic impedance value of the matching layer is matched with the operating frequency of the ultrasonic transducer.

3. The ultrasonic transducer according to claim 2, characterized in that, The flexible conductive substrate includes a flexible substrate and a metal film layer covering both sides of the flexible substrate. The thickness ratio of the metal film layer to the flexible substrate is matched with the operating frequency.

4. The ultrasonic transducer according to claim 1, characterized in that, The matching layer further includes a second flexible circuit board; the second flexible circuit board is located between the first flexible circuit board and the piezoelectric layer; The ultrasonic transducer further includes a third flexible circuit board; the third flexible circuit board is located between the backing layer and the piezoelectric layer; The piezoelectric layer includes: a first electrode and a second electrode; the second electrode is close to and connected to the second flexible circuit board, and the first electrode is close to and connected to the third flexible circuit board.

5. The ultrasonic transducer according to claim 1, characterized in that, The thickness of the backing layer is matched with the operating frequency of the ultrasonic transducer.

6. The ultrasonic transducer according to claim 1, characterized in that, The backing layer includes a base and rods inserted into the base; a plurality of the rods are arranged in the base according to the regular polygonal rule.

7. The ultrasonic transducer according to claim 6, characterized in that, Includes at least one of the following: The plurality of the aforementioned rods are arranged in the base according to a regular hexahedral rule; The material of the rod includes metal or elastic material.

8. The ultrasonic transducer according to claim 1, characterized in that, Includes at least one of the following: The thickness of the matching layer includes one-quarter wavelength of the transmitted ultrasonic wave; The first-order vibration of the piezoelectric layer is longitudinal vibration.

9. A method for manufacturing an ultrasonic transducer, used to manufacture the ultrasonic transducer as described in any one of claims 1-8, characterized in that, include: Manufacturing piezoelectric layers; A matching layer is fabricated, and a flexible dielectric layer and a flexible conductive substrate are alternately stacked to obtain a first flexible circuit board. And the first flexible circuit board is connected to the piezoelectric layer; A backing layer is manufactured, and the backing layer and the piezoelectric layer are coupled together using conductive adhesive.

10. The method for manufacturing an ultrasonic transducer according to claim 9, characterized in that, Connecting the first flexible circuit board to the piezoelectric layer includes: A third flexible circuit board is manufactured by connecting the first electrode of the piezoelectric layer to the third flexible circuit board. A second flexible circuit board is manufactured, and the second electrode of the piezoelectric layer is connected to the second flexible circuit board.

Images