Piezoelectric composite material, manufacturing method and ultrasonic transducer

Abstract

The invention relates to the field of piezoelectric composite materials, and provides a piezoelectric composite material, a manufacturing method and an ultrasonic transducer. The piezoelectric composite material comprises a piezoelectric material, an insulating material, a conductive material and a plating layer, and a first cutting groove is formed in the piezoelectric material; the insulating material is arranged in the first cutting groove, and a second cutting groove is further formed in the insulating material; the conductive material is arranged in the second cutting groove; the plating layers comprise the positive plating layer and the negative plating layer, and the positive plating layer and the negative plating layer are provided with a third cutting groove and a fourth cutting groove respectively, so that the adjacent positive plating layer and negative plating layer are suitable for being conducted and connected in series or not conducted through a conductive material and connected in parallel. The manufacturing method is used for preparing the piezoelectric composite material. The ultrasonic transducer comprises a piezoelectric composite material. According to different use scenes of the transducer, the electrical conduction mode of the coating on the surface of the piezoelectric composite material is simply changed, the electrical impedance matching requirement of an ultrasonic system for the transducer can be met, the research and development period is greatly shortened, and the research and development cost is saved.

Description

Technical Field

[0001] The present invention relates to the field of piezoelectric composite materials, and further to a piezoelectric composite material, a manufacturing method and an ultrasonic transducer. Background Art

[0002] Ultrasonic transducers are a type of sensor that can convert electrical signals into ultrasonic signals. They are widely used in industrial nondestructive testing, sonar and medical ultrasound examinations. Their internal core components are usually piezoelectric polycrystalline or piezoelectric single crystal materials with piezoelectric effect. Taking medical ultrasound applications as an example, the acoustic impedance of piezoelectric materials is usually around 33 MRayl, while the acoustic impedance of human tissue is 1.5 MRayl, and the acoustic reflectivity is 0.834, which means that 83.4% of the ultrasonic energy is reflected back to the piezoelectric material without being transmitted to the human body. In order to allow most of the ultrasonic waves generated by the vibration of the piezoelectric material to be transmitted into the human body, it is necessary to add several layers of acoustic impedance matching layers between the piezoelectric material and the human tissue to reduce the difference in acoustic impedance between the piezoelectric material and the human tissue. In addition to adding an acoustic impedance matching layer, reducing the acoustic impedance of the piezoelectric material can also reduce the acoustic reflectivity, so the use of piezoelectric composite materials has become a design method for many ultrasonic transducers. The conventional method of making piezoelectric composite materials is to fill epoxy resin between the piezoelectric materials to form a 2-2 type, 1-3 type or even a 0-3 type composite material, which effectively reduces the acoustic impedance of the piezoelectric material.

[0003] However, conventional piezoelectric composite materials have a relatively simple function, and each piezoelectric material is electrically connected in parallel. For some transducers with special applications, the electrical impedance of the internal array element is significantly smaller than the electrical impedance of the entire system (usually 50 ohms), which is not conducive to the impedance matching of the transducer array element and the system. Even if the piezoelectric composite material is used to reduce the capacitance of the transducer array element, the electrical impedance of the transducer array element is still small. If the volume ratio of the piezoelectric material in the piezoelectric composite material is further reduced, the piezoelectric performance of the piezoelectric composite material will be affected. Summary of the invention

[0004] In view of the above technical problems, the purpose of the present invention is to provide a piezoelectric composite material, a manufacturing method and an ultrasonic transducer, which can simply change the electrical conduction mode of the surface coating of the piezoelectric composite material according to different usage scenarios of the transducer to meet the electrical impedance matching requirements of the ultrasonic system for the transducer, greatly speed up the R&D cycle and save R&D costs.

[0005] In order to achieve the above object, the present invention provides a piezoelectric composite material, comprising a piezoelectric material, an insulating material, a conductive material and a coating, wherein a plurality of first grooves are provided on the piezoelectric material;

[0006] The insulating material is arranged inside the first groove, and a second groove is also arranged on the insulating material;

[0007] The conductive material is arranged in the second groove; the coating includes a positive electrode coating and a negative electrode coating arranged on both sides of the piezoelectric material, and the positive electrode coating and the negative electrode coating are respectively provided with a third groove and a fourth groove, so that the adjacent positive electrode coating and the negative electrode coating are suitable for being connected through the conductive material and being arranged in series or not being connected through the conductive material and being arranged in parallel.

[0008] In some embodiments, the third groove is arranged above the piezoelectric material and close to one side of the insulating material, and the fourth groove is suitable for being arranged below the piezoelectric material and close to the other side of the insulating material. The third groove and the fourth groove are relatively located on the left and right sides of the insulating material, so that the positive electrode coating and the negative electrode coating of adjacent piezoelectric materials are connected through the conductive material, and the piezoelectric materials are arranged in series.

[0009] In some embodiments, the third groove and the fourth groove are respectively located at the upper and lower ends of the insulating material, so that the positive electrode coating and the negative electrode coating of adjacent piezoelectric materials are not connected through the conductive material, and the piezoelectric materials are arranged in parallel.

[0010] In some embodiments, the widths of the third slot and the fourth slot are greater than the width of the first slot.

[0011] In some embodiments, the piezoelectric composite material is any one of 2-2 type, 1-3 type, and 0-3 type.

[0012] According to another aspect of the present application, a method for preparing a piezoelectric composite material is further provided, which is used to prepare any one of the piezoelectric composite materials in the above preferred embodiments, and the method comprises:

[0013] Processing a plurality of first grooves on the piezoelectric material, and adding insulating material into the first grooves;

[0014] Processing a second groove on the insulating material, and adding a conductive material into the second groove;

[0015] Thinning both sides of the piezoelectric material to a specified thickness so that the conductive material and the insulating material on both sides of the piezoelectric material are exposed;

[0016] A plating layer is formed on both sides of the piezoelectric material, and a third groove and a fourth groove are formed on the plating layer, so that the piezoelectric materials are arranged in series or in parallel.

[0017] In some embodiments, a coating is added to both sides of the piezoelectric material, and a third groove and a fourth groove are formed on the coating so that the piezoelectric material is arranged in series or in parallel, specifically including:

[0018] Select the conduction mode of the coating according to different usage scenarios.

[0019] If it is necessary to connect the piezoelectric materials in series, the third cut groove and the fourth cut groove are arranged on the left and right sides of the insulating material, so that the positive electrode coatings and the negative electrode coatings of adjacent piezoelectric materials are conducted through the conductive material.

[0020] If it is necessary to connect the piezoelectric materials in parallel, the third cut groove and the fourth cut groove are respectively arranged at the upper and lower ends of the insulating material, so that the positive electrode coatings and the negative electrode coatings of adjacent piezoelectric materials are not conducted.

[0021] In some embodiments, after the coatings are plated on both sides of the piezoelectric material, the third cut groove and the fourth cut groove are cut out on the coatings.

[0022] Alternatively, before or when plating the coatings on both sides of the piezoelectric material, a mask plate is arranged on both sides of the piezoelectric material, the mask plate covers the positions of the third cut groove and the fourth cut groove, and then the coatings are plated on both sides of the piezoelectric material.

[0023] In some embodiments, the width w of the first cut groove satisfies w < v / (4√2*f), where v is the shear wave velocity of the insulating material and f is the resonance frequency of the piezoelectric composite material.

[0024] According to another aspect of the present application, an ultrasonic transducer is further provided, which includes any one of the piezoelectric composite materials in the above preferred embodiments.

[0025] Compared with the prior art, the piezoelectric composite material, manufacturing method and ultrasonic transducer provided by the present invention have at least one of the following beneficial effects:

[0026] 1. According to different usage scenarios of the transducer, the electrical conduction mode of the coating on the surface of the piezoelectric composite material can be simply changed to meet the electrical impedance matching requirements of the ultrasonic system for the transducer, greatly shortening the R & D cycle and saving R & D costs.

[0027] 2. Adding the insulating material can prevent the piezoelectric materials from being made into an electrical series structure, and will not affect the vibration modes of the piezoelectric materials due to the possible electric field excitation formed by the conductive material in the second cut groove.

[0028] 3. The third cut groove and the fourth cut groove are relatively located on the left and right sides of the insulating material, and the positive electrode coatings and the negative electrode coatings of adjacent piezoelectric materials are connected, realizing an electrical series structure among the piezoelectric materials in the piezoelectric composite material, significantly reducing the capacitance of the transducer array element and increasing the impedance.

[0029] 4. The third groove and the fourth groove are respectively located at the upper and lower ends of the insulating material, and the positive electrode coating and the negative electrode coating of adjacent piezoelectric materials are not connected, so as to realize the structure of electrical parallel connection between the piezoelectric materials in the piezoelectric composite material and reduce the electrical impedance. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The preferred implementation modes will be described below in a clear and understandable manner with reference to the accompanying drawings to further illustrate the above-mentioned characteristics, technical features, advantages and implementation methods of the present invention.

[0031] Figure 1 It is an overall diagram of a series connection of piezoelectric composite materials;

[0032] Figure 2 It is an overall diagram of a piezoelectric composite material connected in parallel;

[0033] Figure 3 It is the structural diagram of the first groove;

[0034] Figure 4 It is the installation drawing of the insulation material;

[0035] Figure 5 It is the structural diagram of the second groove;

[0036] Figure 6 It is the installation diagram of the conductive material;

[0037] Figure 7 This is the structure diagram of the piezoelectric material after double-sided thinning;

[0038] Figure 8 It is a structural diagram of piezoelectric composite materials in series;

[0039] Fig. 9 It is a structural diagram of piezoelectric composite materials in parallel;

[0040] Fig.10 It is a flow chart of a method for making a piezoelectric composite material.

[0041] Description of Figure Numbers:

[0042] Piezoelectric material 1 , first groove 10 , conductive material 2 , insulating material 3 , second groove 30 , positive electrode coating 4 , third groove 40 , negative electrode coating 5 , fourth groove 50 . DETAILED DESCRIPTION

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings and other implementation methods can be obtained based on these drawings without creative work.

[0044] In order to simplify the drawings, only the parts related to the invention are schematically shown in each figure, and they do not represent the actual structure of the product. In addition, in order to simplify the drawings and facilitate understanding, in some figures, only one of the parts with the same structure or function is schematically drawn or marked. In this article, "one" not only means "only one", but also means "more than one".

[0045] It should be further understood that the term “and / or” used in the specification and appended claims refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0046] In this document, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0047] In addition, in the description of the present application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance. It should be noted that the above embodiments can be freely combined as needed. The above are only preferred implementations of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention, and these improvements and modifications should also be regarded as the scope of protection of the present invention.

[0048] refer to Figure 1 , Figure 2 , Figure 3 as well as Figure 5 The present invention provides a piezoelectric composite material, including a piezoelectric material 1, an insulating material 3, a conductive material 2 and a coating, wherein the piezoelectric material 1 is provided with a plurality of first grooves 10; the insulating material 3 is arranged inside the first grooves 10, the insulating material 3 is further provided with a second groove 30, and the conductive material 2 is arranged in the second groove 30; the coating comprises a positive electrode coating 4 and a negative electrode coating 5 arranged on both sides of the piezoelectric material 1, and the positive electrode coating 4 and the negative electrode coating 5 are respectively provided with a third groove 40 and a fourth groove 50, so that adjacent positive electrode coatings 4 and negative electrode coatings 5 ​​are suitable for being connected through the conductive material 2 and being arranged in series or not being connected through the conductive material 2 and being arranged in parallel.

[0049] In this embodiment, the electrical impedance matching requirements of the ultrasonic system for the transducer can be met by simply changing the electrical conduction mode of the surface coating of the piezoelectric composite material according to different usage scenarios of the transducer, which greatly speeds up the R&D cycle and saves R&D costs.

[0050] Specifically, the present application utilizes two media, a conductive material 2 and an insulating material 3, as the non-piezoelectric phase of the piezoelectric composite material, and changes the electrical connectivity structure of the piezoelectric composite material according to different usage scenarios: when the transducer has no special requirements for the electrical impedance of the array element, it can be used as an ordinary piezoelectric composite material; if the transducer needs to increase the electrical impedance of the array element, the piezoelectric composite material of the present invention only needs to change the connection method of its surface coating to achieve the electrical series structure between the piezoelectric materials 1 in the piezoelectric composite material, significantly reducing the capacitance of the transducer array element and improving the electrical impedance. The insulating material 3 includes but is not limited to epoxy resin materials. The addition of the insulating material 3 can prevent the piezoelectric material 1 from being made into an electrical series structure, and will not affect the vibration mode of each piezoelectric material 1 due to the possible electric field excitation formed by the conductive material 2 in the second groove 30. The conductive material 2 includes but is not limited to conductive silver epoxy materials, and can also be solid conductive materials 2 such as graphite and metal.

[0051] It is worth noting that the side view of the piezoelectric material 1 is used in this embodiment, and only one direction of the groove is shown. In actual application, there can be multiple groove directions to form a 2-2, 1-3 or even 0-3 type piezoelectric composite material structure. That is, the piezoelectric composite material includes but is not limited to any one of the 2-2 type, 1-3 type, and 0-3 type.

[0052] Furthermore, the third groove 40 is arranged above the piezoelectric material 1 and close to one side of the insulating material 3, and the fourth groove 50 is suitable for being arranged below the piezoelectric material 1 and close to the other side of the insulating material 3. The third groove 40 and the fourth groove 50 are relatively located on the left and right sides of the insulating material 3, so that the positive electrode coating 4 and the negative electrode coating 5 of adjacent piezoelectric materials 1 are connected through the conductive material 2. Later, all the positive electrode coatings 4 and the negative electrode coatings 5 ​​are connected separately to form a series arrangement of the piezoelectric material 1.

[0053] In this embodiment, the third groove 40 and the fourth groove 50 are relatively located on the left and right sides of the insulating material 3, and the positive electrode coating 4 and the negative electrode coating 5 of adjacent piezoelectric materials 1 are connected through the conductive material 2, thereby realizing an electrical series structure between the piezoelectric materials 1 in the piezoelectric composite material, significantly reducing the capacitance of the transducer array element and improving the electrical impedance.

[0054] Specifically, the third slot 40 and the fourth slot 50 are relatively located on the left and right sides of the insulating material 3. In this embodiment, the third slot 40 is located on the left side of the insulating material 3, and the fourth slot 50 is located on the right side of the insulating material 3. In a modified embodiment, the third slot 40 is located on the right side of the insulating material 3, and the fourth slot 50 is located on the left side of the insulating material 3, that is, the third slot 40 and the fourth slot 50 are located on both sides of the insulating material 3. The positive electrode coating 4 and the negative electrode coating 5 of the adjacent piezoelectric materials 1 are connected through the conductive material 2, so that the piezoelectric materials 1 in the piezoelectric composite material are electrically connected in series, which can significantly reduce the capacitance of the transducer array element and improve the electrical impedance. Assume that the length, width and thickness of a rectangular piezoelectric material 1 are L*W*T, and the capacitance is C. When the piezoelectric material 1 is divided into two rectangular pieces, that is, the size of each piezoelectric material 1 is L1*W*T and L2*W*T, or the size of each piece is L*W1*T and L*W2*T, the capacitance is C1 and C2 respectively, where L=L1+L2, W=W1+W2, C=C1+C2. After the two pieces of piezoelectric material 1 are electrically connected in series, the total capacitance becomes C1*C2 / (C1+C2). If C1=C2=C / 2, the total capacitance after series connection is C / 4, that is, the capacitance is reduced to one-fourth of the original. By changing the size of L1, L2 or W1, W2, the capacitance can theoretically be reduced to any specified value.

[0055] Furthermore, the third groove 40 and the fourth groove 50 are respectively located at the upper and lower ends of the insulating material 3, so that the positive electrode coating 4 and the negative electrode coating 5 of adjacent piezoelectric materials 1 are not connected through the conductive material 2, and the piezoelectric material 1 is connected in parallel by connecting all the positive electrode coatings 4 and the negative electrode coatings 5.

[0056] In this embodiment, the third groove 40 and the fourth groove 50 are respectively located at the upper and lower ends of the insulating material 3, and the positive electrode coating 4 and the negative electrode coating 5 of adjacent piezoelectric materials 1 are not connected through the conductive material 2, thereby realizing an electrical parallel structure between the piezoelectric materials 1 in the piezoelectric composite material and reducing the electrical impedance.

[0057] Specifically, the third slot 40 and the fourth slot 50 are respectively located at the upper and lower ends of the insulating material 3, and the adjacent piezoelectric materials 1, the positive electrode coating 4 and the negative electrode coating 5 are isolated from each other. At this time, all the positive electrode coatings 4 of the piezoelectric material 1 need to be connected to the signal electrode, and all the negative electrode coatings 5 ​​of the piezoelectric material 1 need to be connected to the ground electrode to achieve the parallel setting of adjacent piezoelectric materials 1. Preferably, the width of the third slot 40 and the fourth slot 50 is greater than the width of the first slot 10 to reduce the risk of contact between adjacent piezoelectric materials 1.

[0058] Further, refer to Fig.10, the present invention provides a method for manufacturing a piezoelectric composite material for preparing a piezoelectric composite material in any of the above embodiments. In this embodiment, for the novel piezoelectric composite material of the present invention, by only changing the connection mode of its surface coating, the application of a pure composite material or a composite material with an electrical series structure can be realized. That is, those skilled in the art can, according to the application scenario of the transducer, without changing the thickness of the composite material, only change the coating connection mode to reduce the capacitance of the transducer element to any specified value, meeting the requirements of different ultrasonic systems for the electrical impedance of the transducer. In this way, the R & D cycle can be greatly accelerated and the R & D cost can be saved. It should be noted that the schematic diagram of the present invention is a side view of a single piezoelectric composite material. Those skilled in the art can decide whether to cut the piezoelectric composite material into several strip-shaped blocks (elements) according to the number of elements depending on whether the transducer is a single element or an array structure, which does not affect the generality of the present invention.

[0059] A method for manufacturing a piezoelectric composite material specifically includes:

[0060] S101 Process a number of first grooves 10 in the piezoelectric material 1 and add an insulating material 3 into the first grooves 10. In this embodiment, referring to Figure 3 and Figure 4 , the first grooves 10 can be processed by blade cutting, or by etching or laser processing. The present application does not make further limitations. The same is true for the subsequent formation of the second grooves 30. The depth of the first grooves 10 is related to the resonance frequency f of the piezoelectric composite material, and the width w of the first grooves 10 is related to the resonance frequency f of the piezoelectric composite material and the shear wave velocity v of the insulating material 3 filled later, and should satisfy w < v / (4√2*f). In this embodiment, the insulating material 3 is epoxy resin, and the conductive material 2 is conductive silver epoxy. Usually, the shear wave velocities of epoxy resin and conductive silver epoxy are close. Therefore, the groove width can be determined according to the shear wave velocity of the epoxy resin and the resonance frequency of the piezoelectric material 1; in the figure, there is 1 first groove 10, and in actual application, any specified number of first grooves 10 arranged at the same interval or different intervals can be cut according to needs.

[0061] S102 Process second grooves 30 in the insulating material 3 and add a conductive material 2 into the second grooves 30. Specifically, referring to Figure 5 and Figure 6In this embodiment, the conductive material 2 is a conductive silver epoxy material, and the conductive silver epoxy material needs to be cured at a specified temperature. The width of the second groove 30 is smaller than the width of the first groove 10, and the depth of the second groove 30 is usually smaller than the first groove 10. At the same time, the depth of the second groove 30 can also be greater than the depth of the first groove 10, but the depth of the second groove 30 should be less than the total thickness of the piezoelectric material 1. In the figure, there is one second groove 30. In actual application, the second groove 30 can be formed in the first groove 10 at any specified position according to the volume ratio of the composite material or the requirements of the electrical impedance. The second groove 30 can be filled with the conductive material 2 by sputtering, vacuum evaporation, physical vapor deposition, arc vapor deposition, ion plating or vacuum deposition.

[0062] S103 thins both sides of the piezoelectric material 1 to a specified thickness, so that the conductive material 2 and the insulating material 3 on both sides of the piezoelectric material 1 are exposed. Figure 7 , exposing the conductive material 2 and the insulating material 3 on both sides of the piezoelectric material 1 is to prepare for the subsequent surface coating process on both sides of the piezoelectric material 1.

[0063] S104 forms a coating on both sides of the piezoelectric material 1, and forms a third groove 40 and a fourth groove 50 on the coating, so that the piezoelectric material 1 is arranged in series or in parallel. Figure 8 and Fig. 9 , a coating is added to the surface of the piezoelectric material 1. The coating is usually two layers but not limited to two layers. The bottom layer is made of nickel, chromium or nickel-chromium layer, and the outer layer is made of gold, silver, copper, aluminum or titanium alloy, so that the surface coating and the conductive material 2 in the second groove 30 are electrically conductive. The coating material of the piezoelectric material 1 is not further limited in this application. At the same time, the coating can be added by sputtering, vacuum evaporation, physical vapor deposition, arc vapor deposition, ion plating or vacuum deposition, as long as it can achieve coating. Figure 8 and Fig. 9 The upper and lower surfaces of the piezoelectric material 1 are plated, and in actual applications, the side surfaces of the piezoelectric material 1 may also be plated as needed.

[0064] Specifically, technicians can select the conduction method of the coating and cut the surface of the coating according to different usage scenarios.

[0065] If the piezoelectric materials 1 need to be connected in series, the third groove 40 and the fourth groove 50 are arranged on the left and right sides of the insulating material 3, so that the positive electrode coating 4 and the negative electrode coating 5 of adjacent piezoelectric materials 1 are connected through the conductive material 2. In this embodiment, the third groove 40 and the fourth groove 50 separate the adjacent positive electrode coatings 4 and the adjacent negative electrode coatings 5 ​​of adjacent piezoelectric materials 1, and connect the positive electrode coating 4 of one piezoelectric material 1 and the negative electrode coating 5 of another piezoelectric material 1 through the conductive material 2 in the second groove 30, forming an electrical series structure of the piezoelectric materials 1. In specific applications, the signal electrode of the transducer is connected to the positive electrode coating 4 of one piezoelectric material 1, and the ground electrode is connected to the negative electrode coating 5 of another piezoelectric material 1, or the signal electrode is connected to the negative electrode coating 5 of one piezoelectric material 1, and the ground electrode is connected to the positive electrode coating 4 of another piezoelectric material 1, and according to the number of the first groove 10 and the second groove 30 and the groove interval, an arbitrarily specified electrical series structure of the piezoelectric material 1 is formed, for example Figure 8 It is a multi-stage series piezoelectric composite material structure. In practical application, only the primary positive electrode coating 4 and the primary negative electrode coating 5 at the end of the series electrical path need to be drawn out. There is no special requirement for the width of the cut coating, and the smaller the better. It is worth noting that according to the different spacings of the coating surface cutting or masking, the piezoelectric material 1 can be formed with a fixed thickness, and the capacitance of the piezoelectric material 1 can be reduced to any specified value.

[0066] If the piezoelectric materials 1 need to be connected in parallel, the third groove 40 and the fourth groove 50 are respectively arranged at the upper and lower ends of the insulating material 3, so that the positive electrode coating 4 and the negative electrode coating 5 of the adjacent piezoelectric materials 1 are not connected through the conductive material 2. In this embodiment, the positive electrode coating 4 and the negative electrode coating 5 of one piezoelectric material 1 are not connected to the positive electrode coating 4 and the negative electrode coating 5 of another piezoelectric material 1, that is, the upper and lower ends of the conductive material 2 of the second groove 30 are not in contact with the positive electrode coating 4 and the negative electrode coating 5. At this time, the piezoelectric composite material of the present invention is only used as a composite material, and according to the number of the first grooves 10 and the second grooves 30 and the groove intervals, a piezoelectric composite material of any volume ratio is formed, and the third groove 40 that cuts off the coating and the width of the third groove 40 are greater than the width of the second groove 30. For example Fig. 9 It is a conventional piezoelectric composite material structure. Different from the multi-stage series structure which only needs to lead out the primary positive electrode coating 4 and the primary negative electrode coating 5, when the conventional piezoelectric composite material structure is used, the positive electrode coating 4 needs to be completely connected to the transducer signal electrode or the ground electrode; the negative electrode coating 5 needs to be completely connected to the transducer ground electrode or the signal electrode, and the positive electrode coating 4 and the negative electrode coating 5 of the piezoelectric composite material are not connected.

[0067] It is worth noting that the third groove 40 and the fourth groove 50 can be formed by plating a coating on both sides of the piezoelectric material 1 and then cutting the third groove 40 and the fourth groove 50 on the coating; or before or when the coating is plated on both sides of the piezoelectric material 1, a mask plate is set on both sides of the piezoelectric material 1, and the mask plate blocks the positions of the third groove 40 and the fourth groove 50. The positions of the third groove 40 and the fourth groove 50 are the parts that need to be cut in the previous method. The mask plate is used to block them so that no coating is formed at this position, but the coating is plated at other positions on both sides of the piezoelectric material 1.

[0068] Furthermore, the present invention provides an ultrasonic transducer, comprising a piezoelectric composite material, a signal electrode and a ground electrode in any of the above embodiments. When the piezoelectric material 1 is in an electrically series structure, the signal electrode is connected to the positive electrode coating 4 of one piezoelectric material 1, and the ground electrode is connected to the negative electrode coating 5 of another piezoelectric material 1, or the signal electrode is connected to the negative electrode coating 5 of one piezoelectric material 1, and the ground electrode is connected to the positive electrode coating 4 of another piezoelectric material 1. When the piezoelectric material 1 is in an electrically parallel structure, it is necessary to connect all the positive electrode coatings 4 to the signal electrode or the ground electrode; all the negative electrode coatings 5 ​​are connected to the ground electrode or the signal electrode, and the positive electrode coating 4 and the negative electrode coating 5 of the piezoelectric composite material are not connected.

[0069] It should be noted that the above embodiments can be freely combined as needed. The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A piezoelectric composite material, characterized in that: include: A piezoelectric material, wherein a plurality of first grooves are provided on the piezoelectric material; Insulating material, the insulating material is arranged inside the first groove, and a second groove is also arranged on the insulating material; A conductive material, wherein the conductive material is disposed in the second groove; The coating comprises a positive electrode coating and a negative electrode coating arranged on both sides of the piezoelectric material, and the positive electrode coating and the negative electrode coating are respectively provided with a third groove and a fourth groove, so that the adjacent positive electrode coating and the negative electrode coating are suitable for being connected through the conductive material and arranged in series or not being connected through the conductive material and arranged in parallel.

2. A piezoelectric composite material according to claim 1, characterized in that: The third groove is arranged above the piezoelectric material and close to one side of the insulating material, and the fourth groove is suitable for being arranged below the piezoelectric material and close to the other side of the insulating material. The third groove and the fourth groove are relatively located on the left and right sides of the insulating material, so that the positive electrode coating and the negative electrode coating of the adjacent piezoelectric materials are connected through the conductive material, and the piezoelectric materials are arranged in series.

3. The piezoelectric composite material according to claim 1, characterized in that: The third groove and the fourth groove are respectively located at the upper and lower ends of the insulating material, so that the positive electrode coating and the negative electrode coating of the adjacent piezoelectric materials are not connected through the conductive material. Later, all the positive electrode coatings and the negative electrode coatings are connected respectively to form a parallel arrangement of the piezoelectric materials.

4. A piezoelectric composite material according to claim 3, characterized in that: The widths of the third slot and the fourth slot are greater than the width of the first slot.

5. The piezoelectric composite material according to claim 1, characterized in that: The piezoelectric composite material is any one of 2-2 type, 1-3 type and 0-3 type.

6. A method for preparing a piezoelectric composite material, used for preparing a piezoelectric composite material according to any one of claims 1 to 5, characterized in that: include: Processing a plurality of first grooves on the piezoelectric material, and adding insulating material into the first grooves; Processing a second groove on the insulating material, and adding a conductive material into the second groove; Thinning both sides of the piezoelectric material to a specified thickness so that the conductive material and the insulating material on both sides of the piezoelectric material are exposed; A plating layer is formed on both sides of the piezoelectric material, and a third groove and a fourth groove are formed on the plating layer, so that the piezoelectric materials are arranged in series or in parallel.

7. The method for manufacturing a piezoelectric composite material according to claim 6, characterized in that: Adding a coating on both sides of the piezoelectric material, and forming a third groove and a fourth groove on the coating so that the piezoelectric material is arranged in series or in parallel, specifically includes: According to different usage scenarios, select the conduction mode of the coating; If the piezoelectric materials need to be connected in series, the third slot and the fourth slot are arranged on the left and right sides of the insulating material, so that the positive electrode coating and the negative electrode coating of the adjacent piezoelectric materials are connected through the conductive material; If the piezoelectric materials need to be connected in parallel, the third groove and the fourth groove are respectively arranged at the upper and lower ends of the insulating material so that the positive electrode coating and the negative electrode coating of adjacent piezoelectric materials are not conductive, and a parallel structure is formed by connecting all the positive electrode coatings and the negative electrode coatings respectively.

8. The method for manufacturing a piezoelectric composite material according to claim 7, characterized in that: After the coating is applied on both sides of the piezoelectric material, the third groove and the fourth groove are cut on the coating; Alternatively, before or when plating the coating layers on both sides of the piezoelectric material, a mask plate is disposed on both sides of the piezoelectric material, the mask plate covers the positions of the third cut groove and the fourth cut groove, and then the coating layers are plated on both sides of the piezoelectric material.

9. The method for manufacturing a piezoelectric composite material according to claim 6, characterized in that: The width w of the first cut groove satisfies w < v / (4√2*f), where v is the shear wave velocity of the insulating material and f is the resonance frequency of the piezoelectric composite material.

10. An ultrasonic transducer, characterized in that: It includes a piezoelectric composite material according to any one of claims 1-5.

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