Microarray ultrasonic transducer, preparation method thereof, and ultrasonic probe comprising same

Abstract

The present invention belongs to the technical field of ultrasonic imaging, and particularly relates to a microarray ultrasonic transducer, a preparation method thereof, and an ultrasonic probe comprising the same. The microarray ultrasonic probe provided by the present invention comprises a flexible circuit board, a piezoelectric wafer, and an acoustic matching layer which are sequentially stacked. The first piezoelectric electrode and the piezoelectric columns of the piezoelectric wafer form a plurality of linear array elements, and any part of each array element can participate in the operation, maximizing the performance of each array element in the length direction, thereby improving the performance of the microarray ultrasonic transducer; the second piezoelectric electrode of the piezoelectric wafer extends from the piezoelectric material layer to the same side as the first piezoelectric electrode, without the need to separately introduce a connecting wire, reducing the size of the microarray ultrasonic transducer in the thickness direction and realizing the miniaturization of the ultrasonic transducer. The preparation method provided by the present invention avoids the problem of complex process caused by the need for fine processing of the connecting wire and precise docking with the second piezoelectric electrode in the preparation process of the conventional ultrasonic transducer.

Description

Technical Field

[0001] The present invention belongs to the technical field of ultrasonic imaging, and particularly relates to a microarray ultrasonic transducer, a preparation method thereof, and an ultrasonic probe including the same. Background Art

[0002] Ultrasonic imaging is widely used in fields such as medical diagnosis and industrial inspection, and has advantages such as non-destructive, convenient, and reliable. The ultrasonic signal generated by the ultrasonic probe propagates in an opaque medium, and then receives information such as the signal intensity, frequency, time, and phase reflected by the opaque object, and processes this information to obtain an intuitive image reflecting the acoustic characteristic distribution of the internal structure of the detected opaque medium.

[0003] The ultrasonic probe is a key component of the ultrasonic imaging device, which mainly includes a piezoelectric transducer, a circuit part, a housing part, etc. inside. According to the number of piezoelectric transducers, the ultrasonic probe can be divided into a single-element ultrasonic probe and a multi-element ultrasonic probe, and the multi-element ultrasonic probe can be further divided into a linear array, a convex array, a planar array, etc. according to the arrangement mode of the transducers.

[0004] The performance of the ultrasonic transducer directly determines the quality of ultrasonic imaging. Its structure generally consists of a piezoelectric sheet, a backing layer, an acoustic matching layer, a flexible circuit board, an acoustic lens, etc. Among them, the piezoelectric sheet 1 includes a piezoelectric layer 11, a first electrode 12, and a second electrode 13, and its setting method is as Figure 1 shown. The second electrode 13 is arranged on both sides of the piezoelectric layer 11, so that both ends in the element length direction cannot participate in the work, which limits the performance of the element in the length direction and then reduces the performance of the ultrasonic transducer; at the same time, due to factors such as materials, in order to obtain a better linear element, the thickness of the second electrode 13 has to be increased, increasing the thickness of the piezoelectric sheet 1. Moreover, when leading the second electrode 13 to the same side as the first electrode 12 for convenient connection to the imaging system, a connecting wire 14 needs to be introduced on the second electrode 13. Introducing the connecting wire 14 complicates the structure and preparation process of the ultrasonic transducer, and fine processing of the introduced connecting wire 14 and precise docking with the second electrode 13 are required. The more complex the process, the more difficult it is to ensure the product quality, especially in the design of some micro ultrasonic transducers. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the existing ultrasonic transducer has a complex product structure and preparation process and poor ultrasonic imaging performance due to the existence of the electrode connecting wire, so as to provide a microarray ultrasonic transducer, a preparation method of the micro ultrasonic transducer, and an ultrasonic probe including the microarray ultrasonic transducer.

[0006] To solve the above technical problems, the technical solution adopted by the present invention is:

[0007] The present invention provides a microarray ultrasonic transducer, which includes a flexible circuit board, a piezoelectric wafer, and an acoustic matching layer that are stacked in sequence:

[0008] A number of linear first circuit electrodes and at least one second circuit electrode are arranged in an array on the flexible circuit board;

[0009] The piezoelectric wafer includes a piezoelectric material layer having piezoelectric columns, a number of linear first piezoelectric electrodes arranged in an array on the surface of the piezoelectric material layer facing the flexible circuit board, and a planar second piezoelectric electrode covering the surface of the piezoelectric material layer facing the acoustic matching layer and extending along a partial edge of the piezoelectric material layer to the surface of the piezoelectric material layer facing the flexible circuit board;

[0010] Among them, a number of the first circuit electrodes are connected to a number of the first piezoelectric electrodes in one-to-one correspondence, the first circuit electrode is connected to the second piezoelectric electrode, and a linear piezoelectric electrode gap is formed between the second piezoelectric electrode and an adjacent first piezoelectric electrode and between two adjacent first piezoelectric electrodes.

[0011] Preferably, for the microarray ultrasonic transducer with this structure, the piezoelectric material layer is selected from 1-3 type piezoelectric composites.

[0012] Further preferably, for the microarray ultrasonic transducer with this structure, a groove structure corresponding to the piezoelectric electrode gap is provided on the surface of the piezoelectric material layer facing the flexible circuit board.

[0013] Preferably, for the microarray ultrasonic transducer with this structure, the linear arrangement of the first piezoelectric electrode and the first circuit electrode is the same, and is selected from any one of a straight line segment, an arc segment, an elliptical arc segment, and a sine curve segment.

[0014] Further preferably, for the microarray ultrasonic transducer with this structure, the first piezoelectric electrodes and the first circuit electrodes form a (1-3)×(8-128) rectangular array;

[0015] Two adjacent first piezoelectric electrodes or two adjacent first circuit electrodes along a direction perpendicular to the linear extension direction are parallel; two adjacent first piezoelectric electrodes or two adjacent first circuit electrodes along a direction parallel to the linear extension direction are staggered.

[0016] Further preferably, for the microarray ultrasonic transducer with this structure, a circuit electrode gap having the same linear shape as the first circuit electrode is provided between two adjacent first circuit electrodes along a direction perpendicular to the linear extension direction;

[0017] The circuit electrode gap is arranged corresponding to the piezoelectric electrode gap and the groove structure.

[0018] Further preferably, for the microarray ultrasonic transducer of this structure, a backing layer is provided on the surface of the flexible circuit board away from the piezoelectric wafer, and an acoustic lens is provided on the surface of the acoustic matching layer away from the piezoelectric wafer;

[0019] The total thickness of the acoustic lens, the acoustic matching layer, the piezoelectric wafer, the flexible circuit board and the backing layer ≤ 1.5 mm, and the total width ≤ 2 mm.

[0020] The present invention provides a preparation method for the microarray ultrasonic transducer as described above, including the following steps:

[0021] Continuous conductive sheet layers are provided on both surfaces and part of the edges of the piezoelectric material layer to form the piezoelectric wafer with a wrapped edge structure;

[0022] The conductive sheet layer on one surface of the piezoelectric wafer is first cut to form the first piezoelectric electrode gap and the non-connected first piezoelectric conductive layer and second piezoelectric conductive layer on both sides of the first piezoelectric electrode gap; the first piezoelectric conductive layer is cut several times to form the linear first piezoelectric electrodes arranged in an array, and the second piezoelectric conductive layer forms the planar second piezoelectric electrode;

[0023] A flexible circuit board is printed to form several first circuit electrodes corresponding to the first piezoelectric electrodes and the second circuit electrode corresponding to the second piezoelectric electrode;

[0024] The piezoelectric wafer is press-connected to the flexible circuit board to realize the one-to-one connection of the first piezoelectric electrodes, and the second piezoelectric electrodes on the same side as the first piezoelectric electrodes are connected to the second circuit electrodes correspondingly; the acoustic matching layer is provided on the surface of the piezoelectric wafer away from the flexible circuit board.

[0025] The present invention also provides another preparation method for the microarray ultrasonic transducer as described above, including the following steps:

[0026] Continuous conductive sheet layers are provided on both surfaces and part of the edges of the piezoelectric material layer to form the piezoelectric wafer with a wrapped edge structure;

[0027] A flexible circuit board is printed to form several linear first circuit electrodes arranged in an array and at least one second circuit electrode;

[0028] The flexible circuit board and the acoustic matching layer are respectively provided on both surfaces of the piezoelectric wafer, and the second circuit electrode is located on the side of the wrapped edge structure;

[0029] Cut the flexible circuit board and the conductive sheet layer along the gaps between the second circuit electrode and the adjacent first circuit electrodes and between two adjacent first circuit electrodes to form a plurality of circuit electrode gaps and corresponding piezoelectric electrode gaps, so as to form the first piezoelectric electrodes arranged in an array and the second piezoelectric electrodes located on the same side as the first piezoelectric electrodes;

[0030] A backing layer is provided on the surface of the flexible circuit board away from the piezoelectric wafer, and an acoustic lens layer is provided on the surface of the acoustic matching layer away from the piezoelectric wafer.

[0031] The present invention provides an ultrasonic probe, comprising:

[0032] A housing having an inner cavity;

[0033] The above-mentioned microarray ultrasonic transducer located in the inner cavity;

[0034] The first circuit electrode and the second circuit electrode of the flexible circuit board in the microarray ultrasonic transducer are respectively led out to the first lead electrode and the second lead electrode outside the housing.

[0035] The technical solution of the present invention has the following advantages:

[0036] 1. The microarray ultrasonic transducer provided by the present invention includes a flexible circuit board, a piezoelectric wafer and an acoustic matching layer which are sequentially stacked. Among them, a plurality of linear first circuit electrodes and at least one second circuit electrode are arranged in an array on the flexible circuit board; the piezoelectric wafer includes a piezoelectric material layer having piezoelectric columns, a plurality of linear first piezoelectric electrodes arranged in an array on the surface of the piezoelectric material layer facing the flexible circuit board, and a planar second piezoelectric electrode covering the surface of the piezoelectric material layer facing the acoustic matching layer and extending along a part of the edge of the piezoelectric material layer to the surface of the piezoelectric material layer facing the flexible circuit board; a plurality of first circuit electrodes are connected to a plurality of first piezoelectric electrodes one by one, the first circuit electrode is connected to the second piezoelectric electrode, and linear piezoelectric electrode gaps are formed between the second piezoelectric electrode and the adjacent first piezoelectric electrode and between two adjacent first piezoelectric electrodes.

[0037] The microarray ultrasonic transducer of this structure has several piezoelectric columns in the piezoelectric material layer. A number of linear first piezoelectric electrodes are arranged on one side surface thereof, and a planar second piezoelectric electrode is arranged on the other side surface. A linear piezoelectric electrode gap is formed between two adjacent first piezoelectric electrodes. The first piezoelectric electrode and the piezoelectric column form several linear array elements, and any part of each array element can participate in the work, maximizing the performance of each array element in the length direction, while reducing the size of the microarray ultrasonic transducer in the thickness direction, realizing the miniaturization of the ultrasonic transducer, and then improving the performance of the microarray ultrasonic transducer. At the same time, the second piezoelectric electrode extends from the piezoelectric material layer to the same side as the first piezoelectric electrode, without the need to separately introduce a connecting wire, avoiding the problem of complex process caused by the need for fine processing of the connecting wire and precise docking with the second piezoelectric electrode in the preparation process of the conventional ultrasonic transducer.

[0038] 2. For the microarray transducer provided by the present invention, the piezoelectric material layer is selected as a 1-3 type piezoelectric composite material, which is formed by several piezoelectric columns perpendicular to the two surfaces of the piezoelectric material layer. This piezoelectric composite material has independent array elements, and each array element will not be affected by other array elements during the working process, and the overall performance is more excellent. More importantly, several piezoelectric columns can be connected in parallel to the same linear first piezoelectric electrode, so as to form a sufficient number of linear array elements, greatly improving the performance of the microarray ultrasonic transducer.

[0039] 3. For the microarray ultrasonic transducer provided by the present invention, the linear type of the first circuit electrode is selected from any one of a straight line segment, an arc segment, an elliptical arc segment, and a sine curve segment. The first piezoelectric electrode and the groove structure are correspondingly selected from any one of the above linear types, so as to form various forms of linear array elements to realize functions such as beam deflection and focusing of the microarray ultrasonic transducer.

[0040] 4. For the microarray ultrasonic transducer provided by the present invention, two adjacent first circuit electrodes are parallel along the direction perpendicular to the linear extension direction, and two adjacent first circuit electrodes are staggered along the direction parallel to the linear extension direction, which can further reduce the distance between the first circuit electrodes under limited processing conditions, so as to realize the miniaturized design of the microarray ultrasonic transducer.

[0041] 5. For the microarray ultrasonic transducer provided by the present invention, the first piezoelectric electrode and the first circuit electrode form a (1~3)×(8~128) rectangular array, and the integrated setting realizes the miniaturization of the ultrasonic transducer.

[0042] 6. The preparation method of the microarray ultrasonic transducer provided by the present invention first cuts the conductive sheet layer on one surface of the piezoelectric wafer to form a plurality of linear first piezoelectric electrodes and at least one second piezoelectric electrode, then connects the first circuit electrode and the second circuit electrode of the flexible circuit board to the first piezoelectric electrode and the second piezoelectric electrode respectively, and finally sets the acoustic matching layer, thus forming the core structure of the microarray ultrasonic transducer. This method has low requirements for cutting accuracy, does not need to separately introduce connection wires, simplifies the preparation process, and improves the production efficiency and yield of the product.

[0043] 7. The preparation method of the microarray ultrasonic transducer provided by the present invention first sets the acoustic matching layer and the flexible circuit board printed with the first circuit electrode and the second circuit electrode on the two surfaces of the piezoelectric wafer respectively, then cuts along the gaps between adjacent second circuit electrodes and first circuit electrodes and the gaps between adjacent two first circuit electrodes, and finally sets the backing layer and the acoustic lens layer respectively, thus forming the core structure of the microarray ultrasonic transducer. In this preparation method, the acoustic matching layer, the piezoelectric wafer, and the flexible circuit board are pressed and formed at one time, solving the problem of increased thickness caused by the conventional bonding and fixing of each layer through the adhesive layer, and this preparation method can provide linear array elements with various array modes and a sufficient number.

[0044] 8. The ultrasonic probe provided by the present invention includes a microarray ultrasonic transducer, a first lead electrode, and a second lead electrode. On the one hand, it realizes the unity of performance improvement and structural miniaturization of the ultrasonic probe, and on the other hand, it is convenient to connect with the imaging host and can be well used for in-vivo ultrasonic imaging. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for use in the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0046] Figure 1 Schematic diagram of the piezoelectric sheet structure of the prior art;

[0047] Figure 2 Schematic diagram of the microarray ultrasonic transducer structure provided by Embodiment 1 of the present invention;

[0048] Figure 3 Schematic diagram of the piezoelectric wafer structure provided by Embodiment 1 of the present invention;

[0049] Figure 4 Schematic diagram of the piezoelectric column structure provided by Embodiment 1 of the present invention;

[0050] Figure 5Schematic enlarged view of the partial structure of the piezoelectric wafer provided in Embodiment 1 of the present invention;

[0051] Figure 6 Top view of the piezoelectric wafer provided in Embodiment 1 of the present invention;

[0052] Figure 7 Schematic structural diagram of the flexible circuit board provided in Embodiment 1 of the present invention;

[0053] Figure 8 Flow chart of the preparation method of the microarray ultrasonic transducer provided in Embodiment 2 of the present invention;

[0054] Figure 9 Another flow chart of the preparation method of the microarray ultrasonic transducer provided in Embodiment 3 of the present invention;

[0055] Figure 10 Schematic structural diagram of the ultrasonic probe provided in Embodiment 4 of the present invention;

[0056] Explanation of reference numerals:

[0057] 1 - Piezoelectric sheet; 11 - Piezoelectric layer; 12 - First electrode; 13 - Second electrode; 14 - Connecting wire;

[0058] 2 - Microarray ultrasonic transducer; 21 - Piezoelectric wafer; 211 - Piezoelectric material layer; 2111 - Piezoelectric column; 2112 - Groove structure; 212 - First piezoelectric electrode; 213 - Second piezoelectric electrode; 22 - Flexible circuit board; 221 - First circuit electrode; 222 - Second circuit electrode; 223 - Circuit electrode gap; 23 - Acoustic matching layer; 24 - Backing layer; 25 - Acoustic lens layer;

[0059] 3 - Ultrasonic probe; 31 - Housing; 32 - Ultrasonic transducer; 33 - Lead-out electrode; 331 - First lead-out electrode; 332 - Second lead-out electrode;

[0060] 4 - Imaging host. Detailed implementation manners

[0061] Next, the technical solutions of the present invention will be clearly and completely described in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of them. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0062] In the description of the present invention, it should be noted that the orientation or positional relationship indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance.

[0063] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", "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 directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0064] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0065] Embodiment 1

[0066] This embodiment provides a microarray ultrasonic transducer 2, as Figure 2 shown, which includes a piezoelectric wafer 21, a flexible circuit board 22, an acoustic matching layer 23, a backing layer 24, and an acoustic lens layer 25.

[0067] The piezoelectric wafer 21 is the core component of the microarray ultrasonic transducer 2. After receiving the voltage, it generates vibrations and outputs ultrasonic waves. The parameters such as the shape, material, and thickness of the piezoelectric wafer 21 directly affect the performance of the microarray ultrasonic transducer 2, and then determine the ultrasonic imaging quality. As Figure 3 shown, the piezoelectric wafer 21 includes a piezoelectric material layer 211, a first piezoelectric electrode 212, and a second piezoelectric electrode 213.

[0068] The shape of the piezoelectric material layer 211 can be selected from geometric shapes such as rectangular, circular, and elliptical. Its material can be selected from piezoelectric single crystals (such as lithium niobate, PMNT, etc.), piezoelectric ceramics (such as PbTiO 3 , PZT, etc.), piezoelectric polymers (such as PVDF, TrFE, etc.), and piezoelectric composites (such as ceramic / polymer, single crystal / polymer, etc.). Its thickness is 20 - 500 μm.

[0069] In this embodiment, the piezoelectric material layer 211 is made of a 1-3 type piezoelectric composite material, which itself has a number of piezoelectric columns 2111 perpendicular to the two surfaces. As Figure 4 shown, the piezoelectric columns 2111 are independent of each other, which helps to form independent array elements. Each array element is not affected by other array elements during operation, making the overall performance more superior. Therefore, the 1-3 type piezoelectric composite material shows more advantages in the manufacturing process than other conventional piezoelectric materials, that is, the above-mentioned several independent piezoelectric columns 2111 can be formed without deep cutting and other processing of the piezoelectric material layer 211. Then, piezoelectric electrodes are arranged on the several independent piezoelectric columns 2111 and connected to the flexible circuit board to form the array element structure of the required form.

[0070] In this embodiment, the piezoelectric material layer 211 is designed as a rectangle. To facilitate the connection of the piezoelectric columns 2111 with other components to form a more ideal linear array element structure, a number of linear groove structures 2112 are formed on one side surface of the piezoelectric material layer 211 by cutting and other methods. As Figure 5 shown, the protruding piezoelectric columns 2111 form a more regular piezoelectric linear array.

[0071] Among them, the linear type of the groove structure 2112 can be any one of geometric linear types such as straight line segments, circular arc line segments, elliptical arc line segments, sine curve segments, etc. Naturally, the piezoelectric linear array can also be selected from the above several linear types; the groove structure 2112 and the piezoelectric linear array each form a (1-3)×(8-128) rectangular array. In this embodiment, both the groove structure 2112 and the piezoelectric linear array are of straight line segment type and are both 2×32 rectangular arrays. The overall extension direction of the linear type of each groove structure 2112 and each piezoelectric linear array is the same as the width direction of the piezoelectric material layer 211; and, two adjacent groove structures 2112 are parallel to each other along the direction perpendicular to the extension direction of their respective linear types, and two adjacent piezoelectric linear arrays are parallel to each other. Two adjacent groove structures 2112 are staggered from each other along the direction parallel to the extension direction of their respective linear types, and two adjacent piezoelectric linear arrays are staggered from each other. As Figure 6 shown, not only a linear array element structure is obtained, but also space is saved.

[0072] Each piezoelectric linear array includes a number of independent piezoelectric columns 2111, and an isolation material such as epoxy glue, air, etc. is filled between each piezoelectric linear array (i.e., in the groove structure 2112). Then, when the piezoelectric columns 2111 of each piezoelectric linear array are connected to other components such as electrodes, the adjacent piezoelectric linear arrays do not affect each other, and a more ideal linear array element structure can be formed, and the ultrasonic performance is improved; at the same time, the thickness of the piezoelectric material layer 211 is preferably designed to be 50-150 μm, more preferably 100 μm, making the ultrasonic transducer more miniaturized.

[0073] As Figure 4 、 Figure 5 andFigure 6 As shown, the first piezoelectric electrode 212 is a plurality of linear arrays, which are arranged on a partial surface of one side of the piezoelectric material layer 211 having the groove structure 2112. The linear type of the first piezoelectric electrode 212 is consistent with that of the piezoelectric line array, and can be selected from any one of geometric linear types such as straight line segments, circular arc line segments, elliptical arc line segments, sine curve segments, etc. In this embodiment, the first piezoelectric electrode 212 is of a straight line segment type and is in a 2×32 rectangular array. It is connected to the piezoelectric line array one by one through evaporation coating, without using an adhesive layer, reducing the thickness of the ultrasonic transducer.

[0074] As Figure 3 shown, the second piezoelectric electrode 213 is rectangular and completely covers the other side surface of the piezoelectric material layer 211, that is, the opposite side of the groove structure 2112, and at least one end extends along a partial edge of the piezoelectric material layer 211 to the side of the first piezoelectric electrode 212 to form a wrapped edge structure, and a piezoelectric electrode gap (not marked in the figure) is formed between it and the first piezoelectric electrode 212. This piezoelectric electrode gap corresponds to the groove structure 2112, as Figure 5 shown. In this embodiment, both ends of the second piezoelectric electrode 213 extend along the two short sides of the piezoelectric material layer 211 to the side of the first piezoelectric electrode 212 to form a double-sided wrapped edge structure.

[0075] Both the above-mentioned first piezoelectric electrode 212 and second piezoelectric electrode 213 are gold evaporation electrodes with a thickness of 200 nm to 800 nm, preferably 500 nm, reducing the size of the microarray ultrasonic transducer 2 in the thickness direction. And through the double-sided wrapped edge structure of the second piezoelectric electrode 213, it is realized on the same side as the first piezoelectric electrode 212, without the need to separately introduce a connecting wire, and it avoids the problem of complex process caused by the need for fine processing of the connecting wire and precise docking with the second piezoelectric electrode 213 in the preparation process of the conventional ultrasonic transducer. At the same time, the first piezoelectric electrode 212 is linear and the second piezoelectric electrode 213 is planar, forming a good linear array element structure.

[0076] As Figure 2 and Figure 7As shown, the flexible circuit board 22 is disposed on one surface of the piezoelectric material layer 211 having the groove structure 2112, with a thickness of 40 μm, and includes a first circuit electrode 221, a second circuit electrode 222, and a circuit electrode gap 223. A plurality of first circuit electrodes 221 are provided, forming a (1-3)×(8-128) rectangular array, which is consistent with the arrangement of the piezoelectric line array, so as to facilitate one-to-one connection between the two; the first circuit electrode 221 is linear and is selected from any one of geometric linear types such as a straight line segment, an arc line segment, an elliptical arc segment, a sine curve segment, etc. In this embodiment, a plurality of first circuit electrodes 221 are arranged in a 2×32 rectangular array, and the linear type of each first circuit electrode 221 is selected as a straight line segment type consistent with the first piezoelectric electrode 212, and the extending direction of its linear type is parallel to the width direction of the piezoelectric wafer 21. Moreover, two adjacent first circuit electrodes 221 are parallel along the direction perpendicular to the extending direction of the linear type, and the gap therebetween forms a linear circuit electrode gap 223, and the circuit electrode gap 223 is consistent with the linear type of the first circuit electrode 221, that is, the circuit electrode gap 223 is also consistent with the groove structure 2112 and the piezoelectric electrode gap linear setting method; two adjacent first circuit electrodes 221 are staggered along the direction parallel to the extending direction of the linear type. The second circuit electrode 222 is disposed at both ends of the flexible circuit board 22, and a circuit electrode gap 223 is also provided between the second circuit electrode 222 and the adjacent first circuit electrode 221 to realize non-connection between the second circuit electrode 222 and the first circuit electrode 221. The flexible circuit board 22 is press-fitted on the piezoelectric wafer 21 to connect a plurality of first circuit electrodes 221 with a plurality of first piezoelectric electrodes 212 one-to-one, connect the second circuit electrode 222 with the second piezoelectric electrode 213, and at the same time, the groove structure 2112 and the piezoelectric electrode gap also correspond to the circuit electrode gap 223, realizing the connection between the flexible circuit board 22 and the piezoelectric wafer 21.

[0077] As Figure 2 shown, the acoustic matching layer 23 has a thickness of 5-100 μm, preferably 50 μm, and is disposed on one surface of the piezoelectric wafer 21 away from the flexible circuit board 22; the backing layer 24 has a thickness of 200-800 μm, preferably 500 μm, and is disposed on one surface of the flexible circuit board 22 away from the piezoelectric wafer 21; the acoustic lens layer 25 has a thickness of 100-500 μm, preferably 300 μm, and is disposed on one surface of the acoustic matching layer 23 away from the piezoelectric wafer 21. The total thickness of each layer (acoustic lens layer 25, acoustic matching layer 23, piezoelectric wafer 21, flexible circuit board 22, and backing layer 24) of the microarray ultrasonic transducer with this structure is ≤1.5 mm, and the total width is ≤2 mm.

[0078] Embodiment 2

[0079] This embodiment provides a preparation method of a microarray ultrasonic transducer as described in Embodiment 1. As Figure 8 shown, it includes the following steps:

[0080] Step 1: Prepare a piezoelectric wafer with a edge-wrapping structure

[0081] On both surfaces and part of the edges of the piezoelectric material layer 211, a continuous conductive sheet layer is provided to form a piezoelectric wafer 21 with an edge-wrapping structure. Specifically, on the upper and lower surfaces and two short sides of a rectangular 1-3 type piezoelectric composite material, a continuous conductive sheet layer is provided by means of evaporation coating, electrochemical deposition, magnetron sputtering, etc. The conductive sheet layer only covers the two short sides of the piezoelectric material layer 211, and no conductive sheet layer is provided on the two long sides, thus forming a piezoelectric wafer 21 with a double-sided edge-wrapping structure. In this embodiment, the evaporation coating method is adopted.

[0082] As an alternative embodiment, the conductive sheet layer can also only cover the two long sides of the piezoelectric material layer 211, and no conductive sheet layer is provided on the two short sides.

[0083] As an alternative real-time method, the conductive sheet layer can also only cover one edge, such as only covering one long side or only covering one short side, as long as part of the edge is covered.

[0084] Step 2: Form a first piezoelectric electrode and a second piezoelectric electrode

[0085] Along the edge-wrapping structure (i.e., parallel to the short side direction of the piezoelectric material layer 211), the conductive sheet layer on one surface of the piezoelectric wafer 21 in the first step is first cut to form a first piezoelectric electrode gap, and then the conductive sheet layer is divided into a first piezoelectric conductive layer and a second piezoelectric conductive layer that are not connected to each other on both sides of the first piezoelectric electrode gap;

[0086] Along the direction of the first piezoelectric electrode gap, the first piezoelectric conductive layer is cut several times to form a plurality of linearly arranged and parallel first piezoelectric electrodes 212;

[0087] The second piezoelectric conductive layer is not cut to form a planar second piezoelectric electrode 213.

[0088] Since the 1-3 type piezoelectric composite material has a piezoelectric column 2111 structure, the above cutting depth is controlled to be greater than or equal to the thickness of the first piezoelectric conductive layer, which can ensure that the first piezoelectric conductive layer is cut off, simplifying the process; the cutting depth can also extend into the piezoelectric material layer 211 to form a groove structure 2112, thereby making the performance of the formed linear array element structure better.

[0089] In this embodiment, the cutting depth only cuts off the first piezoelectric conductive layer.

[0090] Step 3: Print a flexible circuit board

[0091] Print a flexible circuit board 22 to form a plurality of first circuit electrodes 221 corresponding to the first piezoelectric electrodes 212 and a second circuit electrode 222 corresponding to the second piezoelectric electrode 213.

[0092] Step 4: Laminating and molding the piezoelectric wafer, flexible circuit board, and acoustic matching layer

[0093] First, the flexible circuit board 22 is disposed on one surface of the piezoelectric wafer 21 having a piezoelectric electrode gap by means of press fitting, such that the first piezoelectric electrode 212 is connected to the first circuit electrode 221 in a one-to-one correspondence, and the second piezoelectric electrode 213 on the same side as the first piezoelectric electrode 212 is connected to the second circuit electrode 222. Then, the acoustic matching layer 23 is disposed on the other surface of the piezoelectric wafer 21 away from the flexible circuit board 22 by means of press fitting, thereby forming the core structure of the microarray ultrasonic transducer 2.

[0094] For the preparation method provided in this embodiment, only the piezoelectric material layer 211 needs to be cut to form the piezoelectric electrode array structure, and then the flexible circuit board 22 printed with circuit electrodes, the acoustic matching layer 23, and the piezoelectric wafer 21 are laminated and molded to form the core structure of the microarray ultrasonic transducer 2, without the need to cut the flexible circuit board 22.

[0095] Embodiment 3

[0096] This embodiment provides another preparation method of the microarray ultrasonic transducer as described in Embodiment 1, as Figure 9 shown, including the following steps:

[0097] Step 1: Preparing a piezoelectric wafer with a edge wrapping structure

[0098] Continuous conductive sheet layers are provided on both surfaces and part of the edges of the piezoelectric material layer 211 to form a piezoelectric wafer 21 with an edge wrapping. Specifically, continuous conductive sheet layers are provided on the upper and lower surfaces and two short sides of the rectangular 1-3 type piezoelectric composite material by means of evaporation coating, electrochemical deposition, magnetron sputtering, etc. The conductive sheet layer only wraps the two short sides of the piezoelectric material layer 211, and no conductive sheet layer is provided on the two long sides, thereby forming a piezoelectric wafer 21 with a double-sided edge wrapping structure. In this embodiment, the evaporation coating method is adopted.

[0099] As an alternative implementation, the conductive sheet layer can also only wrap the two long sides of the piezoelectric material layer 211, and no conductive sheet layer is provided on the two short sides.

[0100] As an alternative real-time method, the conductive sheet layer can also only wrap one edge, such as only wrapping one long side or only wrapping one short side, as long as part of the edge is wrapped.

[0101] Step 2: Printing the flexible circuit board

[0102] The flexible circuit board 22 is printed to form a plurality of first circuit electrodes 221 and at least one second circuit electrode 222.

[0103] In this embodiment, two second circuit electrodes 222 are formed.

[0104] Step 3: The piezoelectric wafer, flexible circuit board, and acoustic matching layer are laminated and formed

[0105] The flexible circuit board 22 and the acoustic matching layer 23 are disposed on two surfaces of the piezoelectric wafer 21 by means of crimping, such that the second circuit electrode 222 is located on the side of the edge structure, and the extending directions of the first circuit electrode 221 and the second circuit electrode 222 are the same as the width direction of the piezoelectric wafer 21.

[0106] Step 4: Form the first piezoelectric electrode and the second piezoelectric electrode

[0107] Cut along the gaps between the second circuit electrode 222 and the adjacent first circuit electrode 221 and the gaps between two adjacent first circuit electrodes 221, such that a plurality of circuit electrode gaps 223 are formed on the flexible circuit board 22, piezoelectric electrode gaps corresponding to the circuit electrode gaps 223 are formed on the conductive sheet layer, and groove structures 2112 corresponding to the circuit electrode gaps 223 are formed on the piezoelectric wafer 21. Then, a plurality of linear first piezoelectric electrodes 212 arranged in an array and at least one second piezoelectric electrode 213 are formed on the conductive sheet layer, and the second piezoelectric electrode 213 and the first piezoelectric electrode 212 are located on the same side of the piezoelectric material layer 211, such that the first piezoelectric electrode 212 is connected to the first circuit electrode 221 in a one-to-one correspondence, and the second piezoelectric electrode 213 on the same side as the first piezoelectric electrode 212 is connected to the second circuit electrode 222. The other side of the piezoelectric wafer 21 is not cut, and a planar second piezoelectric electrode 213 is formed.

[0108] Since the 1-3 type piezoelectric composite material has a piezoelectric column 2111 structure, the above cutting depth is controlled to be greater than or equal to the thickness of the first piezoelectric conductive layer, which can ensure that the first piezoelectric conductive layer is cut off, simplifying the process; the cutting depth can also extend into the piezoelectric material layer 211 to form groove structures 2112, thereby making the performance of the formed linear array element structure better.

[0109] In this embodiment, the cutting depth can also extend into the piezoelectric material layer 211 to form groove structures 2112.

[0110] Step 5: The backing layer and the acoustic lens layer are laminated

[0111] The backing layer 24 is laminated on the surface of the flexible circuit board 22 away from the piezoelectric wafer 21, and the acoustic lens layer 25 is laminated on the surface of the acoustic matching layer 23 away from the piezoelectric wafer 21, thus forming the microarray ultrasonic transducer 2.

[0112] In the preparation method provided in this embodiment, the flexible circuit board 22 and the piezoelectric wafer 21 are first press-connected and then cut, so as to form a piezoelectric electrode array structure and a circuit electrode array structure, and the connection between the piezoelectric electrode and the corresponding circuit electrode is realized. Then, the backing layer 24 and the acoustic lens layer 25 are press-connected with the above structure to form the microarray ultrasonic transducer 2.

[0113] Embodiment 4

[0114] This embodiment provides an ultrasonic probe 3, as Figure 10 shown, which includes a housing 31, an ultrasonic transducer 32, and a lead-out electrode 33.

[0115] The housing 31 has an inner cavity; the ultrasonic transducer 32 is located in this inner cavity and uses the microarray ultrasonic transducer provided in Embodiment 1; one end of the lead-out electrode 33 is connected to the circuit electrode in the ultrasonic transducer 32, and the other end is connected to the imaging host 4; wherein, the lead-out electrode 33 includes a first lead-out electrode 331 and a second lead-out electrode 332, which are respectively connected to the first circuit electrode 221 and the second circuit electrode 222.

[0116] Obviously, the above embodiments are only examples for clear illustration and are not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or variations can be made based on the above description. It is not necessary and impossible to list all the implementation manners here. And the obvious changes or variations derived therefrom are still within the protection scope of the present invention.

Claims

1. A microarray ultrasonic transducer, comprising a flexible circuit board, a piezoelectric wafer, and an acoustic matching layer that are sequentially stacked. Characterized in that: A number of linear first circuit electrodes and at least one second circuit electrode are arranged in an array on the flexible circuit board; The piezoelectric wafer includes a piezoelectric material layer having piezoelectric columns, a number of linear first piezoelectric electrodes arranged in an array on the surface of the piezoelectric material layer facing the flexible circuit board, and a planar second piezoelectric electrode covering the surface of the piezoelectric material layer facing the acoustic matching layer and extending along a part of the edge of the piezoelectric material layer to the surface of the piezoelectric material layer facing the flexible circuit board; Among them, a number of the first circuit electrodes are connected to a number of the first piezoelectric electrodes in one-to-one correspondence, the first circuit electrode is connected to the second piezoelectric electrode, and a linear piezoelectric electrode gap is formed between the second piezoelectric electrode and the adjacent first piezoelectric electrode and between two adjacent first piezoelectric electrodes; The piezoelectric material layer is selected from 1-3 type piezoelectric composites; the piezoelectric material layer has a number of piezoelectric columns perpendicular to the two surfaces; the piezoelectric columns are independent of each other to form a linear piezoelectric array, and an isolation material is filled between each linear piezoelectric array; A groove structure corresponding to the piezoelectric electrode gap is provided on the surface of the piezoelectric material layer facing the flexible circuit board; The first piezoelectric electrodes are a number of linear arrays, arranged on a part of the surface of the piezoelectric material layer having the groove structure, and the first piezoelectric electrodes correspond to the linear piezoelectric arrays one by one; Both ends of the second piezoelectric electrode extend along the two short sides of the piezoelectric material layer to the side of the first piezoelectric electrode to form a wrapping structure.

2. The microarray ultrasonic transducer according to claim 1, Characterized in that, The linear arrangement of the first piezoelectric electrode and the first circuit electrode is the same, and is selected from any one of a straight line segment, a circular arc segment, an elliptical arc segment, and a sine curve segment.

3. The microarray ultrasonic transducer according to claim 2, Characterized in that, The first piezoelectric electrode and the first circuit electrode form a (1-3)×(8-128) rectangular array; Two adjacent first piezoelectric electrodes or two adjacent first circuit electrodes along the direction perpendicular to the linear extension direction are parallel; two adjacent first piezoelectric electrodes or two adjacent first circuit electrodes along the direction parallel to the linear extension direction are staggered.

4. The microarray ultrasonic transducer according to claim 3, Characterized in that, A circuit electrode gap having the same linear type as the first circuit electrode is provided between two adjacent first circuit electrodes along the direction perpendicular to the linear extension direction; The circuit electrode gap is arranged corresponding to the piezoelectric electrode gap and the groove structure.

5. The microarray ultrasonic transducer according to any one of claims 1-4, Characterized in that, A backing layer is provided on the surface of the flexible circuit board away from the piezoelectric wafer, and an acoustic lens is provided on the surface of the acoustic matching layer away from the piezoelectric wafer; The total thickness of the acoustic lens, the acoustic matching layer, the piezoelectric wafer, the flexible circuit board, and the backing layer ≤ 1.5 mm, and the total width ≤ 2 mm.

6. A preparation method of the microarray ultrasonic transducer as described in claim 1, characterized in that, it includes the following steps: A continuous conductive sheet layer is provided on two surfaces and part of the edges of the piezoelectric material layer to form the piezoelectric wafer with an edge-wrapping structure; The conductive sheet layer on one surface of the piezoelectric wafer is first cut to form the first piezoelectric electrode gap and the non-connected first piezoelectric conductive layer and second piezoelectric conductive layer on both sides of the first piezoelectric electrode gap; The first piezoelectric conductive layer is cut several times to form the linear first piezoelectric electrodes arranged in an array, and the second piezoelectric conductive layer forms the planar second piezoelectric electrode; A flexible circuit board is printed to form several first circuit electrodes corresponding to the first piezoelectric electrodes and the second circuit electrode corresponding to the second piezoelectric electrode; The piezoelectric wafer is crimped with the flexible circuit board to realize the connection of the first piezoelectric electrode in one-to-one correspondence, and the second piezoelectric electrode on the same side as the first piezoelectric electrode is connected to the second circuit electrode correspondingly; the acoustic matching layer is provided on the surface of the piezoelectric wafer away from the flexible circuit board.

7. A preparation method of the microarray ultrasonic transducer as described in claim 5, characterized in that, it includes the following steps: A continuous conductive sheet layer is provided on two surfaces and part of the edges of the piezoelectric material layer to form the piezoelectric wafer with an edge-wrapping structure; A flexible circuit board is printed to form several linear first circuit electrodes arranged in an array and at least one second circuit electrode; The flexible circuit board and the acoustic matching layer are respectively arranged on two surfaces of the piezoelectric wafer, and the second circuit electrode is located on the side of the edge-wrapping structure; The flexible circuit board and the conductive sheet layer are cut along the gap between the second circuit electrode and the adjacent first circuit electrode and the gap between two adjacent first circuit electrodes to form several circuit electrode gaps and the corresponding piezoelectric electrode gaps, so as to form the first piezoelectric electrodes arranged in an array and the second piezoelectric electrodes on the same side as the first piezoelectric electrodes; The backing layer is provided on the surface of the flexible circuit board away from the piezoelectric wafer, and the acoustic lens layer is provided on the surface of the acoustic matching layer away from the piezoelectric wafer.

8. An ultrasonic probe, characterized in that, it includes: A housing with an inner cavity; The microarray ultrasonic transducer as described in any one of claims 1-5 located in the inner cavity; The first lead electrode and the second lead electrode that lead out the first circuit electrode and the second circuit electrode of the flexible circuit board in the microarray ultrasonic transducer to the outside of the housing respectively.

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