Ultrasonic transducer and method of making the same

Abstract

The present application relates to an ultrasonic transducer and its manufacturing method, the ultrasonic transducer includes: flexible carrier;N groups of piezoelectric elements arranged in annular array form are accommodated in the flexible carrier, N≥2;Array element electrode lead is respectively arranged for the plurality of piezoelectric elements;The ground electrode layer for the mutual electrical conduction of the plurality of piezoelectric elements, the ground electrode layer is located on the opposite side of the array element electrode lead;Flexible signal conducting layer with the same layer number N S of piezoelectric element group number is sequentially arranged on the flexible carrier, the flexible signal conducting layer has the front side of array element electrode lead side and the back side opposite to the front side, N S ≥2;Flexible circuit board is respectively arranged corresponding to the back of each layer of flexible signal conducting layer;Array element electrode lead on the N S group of piezoelectric elements is electrically connected with the flexible circuit board on the back of the N layer of flexible signal conducting layer.The above-mentioned ultrasonic transducer has better self-adaptive ability for different test surfaces, and the signal transmission of each group of piezoelectric elements is relatively independent, and will not interfere with each other.

Description

Technical Field

[0001] This invention relates to the field of ultrasonic imaging equipment technology, and in particular to an ultrasonic transducer and its manufacturing method. Background Technology

[0002] Several diseases, such as Parkinson's disease, Alzheimer's disease, epilepsy, and depression, are related to neurological dysfunction, leading to increasing research interest in neurostimulation both domestically and internationally. Two common neurostimulation methods are electrical stimulation and magnetic stimulation. Electrical stimulation is invasive or minimally invasive, while magnetic stimulation, though non-invasive, suffers from imprecise localization and poor resolution. Therefore, researchers have proposed ultrasound neurostimulation. This method combines ultrasound neurostimulation with magnetic resonance imaging (MRI). MRI is used to determine the positional relationship between the transducer and the target stimulation area, while the transducer focuses the stimulation on the target area.

[0003] However, the commonly used ultrasound transducers for brain nerve stimulation in China are medical diagnostic ultrasound transducers. These transducers are usually planar or convex probes, and the surface of the transducer does not fit well with the scalp during brain stimulation, resulting in poor focusing effect. Summary of the Invention

[0004] Therefore, it is necessary to provide an ultrasonic transducer and its manufacturing method to address the problem of poor fit of existing ultrasonic transducers in non-planar application scenarios.

[0005] An ultrasonic transducer, comprising:

[0006] Flexible vehicle;

[0007] N sets of piezoelectric array elements arranged in a ring array within the flexible carrier, where N≥2;

[0008] Element electrode leads are respectively provided for the plurality of piezoelectric elements;

[0009] A ground electrode layer that enables the plurality of piezoelectric array elements to conduct electricity to each other, wherein the ground electrode layer is located on the opposite side of the array element electrode leads;

[0010] The piezoelectric array elements are sequentially arranged on the flexible carrier in layers N, having the same number of layers as the piezoelectric array elements. S A flexible signal conducting layer, the flexible signal conducting layer having a front side on the electrode lead side of the array element and a back side opposite to the front side, N S ≥2;

[0011] Flexible circuit boards are respectively configured on the back side of each flexible signal transmission layer;

[0012] The element electrode leads on the Nth group of piezoelectric elements pass through the Nth group of piezoelectric elements. SThe flexible signal transmission layer is electrically connected to the flexible circuit board on the back of the layer.

[0013] In one embodiment, the system further includes a plurality of conductive channels disposed on the back side of each flexible signal transmission layer, wherein each of the array element electrode leads is electrically connected to the flexible circuit board through a corresponding conductive channel.

[0014] In one embodiment, the conductive channel is a conductive material that fills and fits into an elongated groove in the radial direction of the flexible signal transmission layer.

[0015] In one embodiment, the system further includes electrode lead vias disposed on each of the flexible signal conduction layers. The array element electrode leads are connected to the distal end of the conductive channel through the corresponding electrode lead vias, and the proximal end of the conductive channel is electrically connected to the flexible circuit board of that layer.

[0016] In one embodiment, the electrode lead vias are arranged in a ring array on each flexible signal conduction layer, and the number of array groups M of the electrode lead vias is equal to the number of flexible signal conduction layers N. S It has the following relationship:

[0017] M = N S(max) -(N S -1)

[0018] Where, N S(max) This represents the maximum number of layers in the flexible signal transmission layer.

[0019] In one embodiment, the system further includes a plurality of conductive pins vertically disposed on the back side of the plurality of flexible circuit boards, wherein the conductive pins of the corresponding layers are electrically connected to the conductive channels one by one.

[0020] In one embodiment, the flexible signal transmission layer is provided with external circuit vias for the corresponding conductive needles to pass through.

[0021] In one embodiment, the external circuit vias are arranged in a ring array on each flexible signal conduction layer, and the number of array groups K of the external circuit vias is related to the number of flexible signal conduction layers N. S It has the following relationship:

[0022] K = N S -1

[0023] Where, N S(max) This represents the maximum number of layers in the flexible signal transmission layer.

[0024] In one embodiment, the piezoelectric element has a positive electrode layer on its back side that is connected to the element's electrode leads.

[0025] A method for manufacturing an ultrasonic transducer includes the following steps:

[0026] Prepare a flexible carrier having multiple receiving cavities arranged in a ring array, wherein the number of ring array groups N≥2;

[0027] Preparation of N S A flexible circuit board with a corresponding number of flexible signal conduction layers, wherein each flexible signal conduction layer has interconnected electrode lead vias and conductive grooves, and the flexible board has metal solder joints. S ≥2;

[0028] Liquid conductive material is filled into the conductive groove of each flexible signal transmission layer, and then the corresponding flexible circuit board is stacked on the back of the flexible signal transmission layer to form multiple bonding layers. The metal solder joints are accommodated in the conductive groove to bond with the conductive material. After the conductive material is cured, a conductive channel electrically connected to the flexible circuit board is formed.

[0029] Multiple bonding layers are stacked to form a stack body;

[0030] The flexible carrier is stacked on the front side of the first flexible signal transmission layer in the stack, and the receiving cavity corresponds one-to-one with the electrode lead via.

[0031] The cavity is filled with a liquid conductive material, which, after solidification, forms an array element electrode lead that electrically connects the conductive channel.

[0032] The piezoelectric element is placed inside the receiving cavity and electrically connected to the electrode leads of the element.

[0033] In one embodiment, each flexible signal transmission layer is further formed with an external circuit via. After forming a conductive channel that electrically connects the flexible circuit board and before forming the stack, the embodiment further includes providing a conductive pin on the back of each flexible circuit board. When the bonding layers are stacked to form the stack, the conductive pin passes through the corresponding external circuit via and is exposed to the stack.

[0034] In one embodiment, a ground electrode layer is disposed on the front side of the plurality of piezoelectric elements.

[0035] In one embodiment, a positive electrode layer is provided on the back of the piezoelectric element or at the bottom of the receiving cavity before the piezoelectric element is placed in the receiving cavity.

[0036] The aforementioned ultrasonic transducer arranges multiple piezoelectric elements in a two-dimensional ring array within a flexible carrier. It incorporates a flexible signal transmission layer with the same number of layers as the piezoelectric element groups, and a flexible circuit board on each layer. The element leads of each group of piezoelectric elements are electrically connected to their respective flexible circuit boards via conductive channels on the corresponding flexible signal transmission layer. Due to the excellent deformation and deformation recovery capabilities of the flexible carrier, flexible signal transmission layer, and flexible circuit board, the ultrasonic transducer exhibits superior adaptability to different test surfaces, significantly improving fit. Furthermore, since each group of piezoelectric elements has a corresponding electrically connected flexible circuit board, the signal transmission of each group is relatively independent and does not interfere with each other, facilitating rapid fault diagnosis. Attached Figure Description

[0037] Figure 1 This is an exploded structural diagram of an ultrasonic transducer according to an embodiment of the present invention.

[0038] Figure 2 This is a schematic diagram of the structure of an ultrasonic transducer according to an embodiment of the present invention.

[0039] Figure 3 for Figure 2 A sectional view.

[0040] Figure 4 This is a cross-sectional view of the flexible carrier in an ultrasonic transducer according to an embodiment of the present invention.

[0041] Figure 5 This is a cross-sectional view of the flexible carrier and piezoelectric array element in an ultrasonic transducer according to an embodiment of the present invention.

[0042] Figure 6 for Figure 3 A schematic diagram of the structure of region A in the middle.

[0043] Figure 7 This is an exploded structural diagram of an ultrasonic transducer according to an embodiment of the present invention.

[0044] Figure 8 This is a schematic diagram of the exploded structure of an ultrasonic transducer in one embodiment of the present invention from another angle.

[0045] Figure 9 This is a projection diagram of the third conductive layer in an ultrasonic transducer according to an embodiment of the present invention.

[0046] Figure 10 This is a projection diagram of the sixth conductive layer in an ultrasonic transducer according to an embodiment of the present invention. Detailed Implementation

[0047] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the description of the present invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0048] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0049] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly specified. In this invention, unless otherwise explicitly specified and limited, "on" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact through an intermediate medium.

[0050] See also Figure 1 and Figure 2 As shown, Figure 1 and Figure 2 The following diagrams illustrate the structure of an ultrasonic transducer according to an embodiment of the present invention from different perspectives. The ultrasonic transducer includes a flexible carrier 10, a plurality of piezoelectric elements 20, a flexible signal transmission layer 30, and a flexible circuit board 40. The piezoelectric elements 20 are embedded within the flexible carrier 10. A ground electrode layer 50 is provided on the side of the piezoelectric elements 20 facing the outside of the flexible carrier 10. The flexible signal transmission layer 30 is disposed on the side of the flexible carrier 10 away from the ground electrode layer 50. The flexible circuit board 40 is disposed on the side of the flexible signal transmission layer 30 away from the flexible carrier 10. It should be noted that these diagrams are provided for easier observation of the components of the ultrasonic transducer. Figure 1The ground electrode layer 50 and the piezoelectric array element 20 are in a decomposed state. In fact, as shown in the figure... Figure 2 As shown, the ground electrode layer 50 is tightly attached to the front side of the piezoelectric array element 20.

[0051] The flexible carrier 10 is used to mount the piezoelectric array element 20 and support the flexible signal conduction layer 30 and flexible circuit board 40, etc. The flexible signal conduction layer 30 is used to connect the piezoelectric array element 20 and the flexible circuit board 40 respectively, so that the piezoelectric array element 20 and the flexible circuit board 40 can be signal connected. The flexible circuit board 40 is used to connect with external circuits to realize signal transmission between the piezoelectric array element 20 and the external circuits. The ground electrode layer 50 is used to make the multiple piezoelectric array elements 20 electrically conductive to each other.

[0052] In the following description, the direction of the flexible signal transmission layer 30 toward the piezoelectric array element 20 is referred to as "above," and "above" means... Figure 1 In the z-direction, the direction opposite to "above" is called "below". The side of the ultrasonic transducer where each component is located at the top is called the "front", and the side where it is located at the bottom is called the "back". In other words, the two opposite sides of the ultrasonic transducer are called the "front" and the "back".

[0053] The flexible carrier 10 is made of a flexible material, and its performance is not affected by deformation. The material of the flexible carrier 10 can be silicone or plastic, or any other material that can change shape according to the shape of the surface it is bonded to during use, and can return to its original shape after detachment from the surface. The flexible signal transmission layer 30 is also made of a flexible material. The flexible circuit board 40 is a printed circuit board with excellent flexibility, being thin and highly flexible.

[0054] See Figure 3 , Figure 4 and Figure 5 As shown, Figure 3 It shows Figure 2 Cross-sectional view along the AA direction. Figure 4 Only a cross-sectional view of the flexible vehicle 10 is shown. Figure 5 A cross-sectional view of the flexible carrier 10 and the piezoelectric array elements 20 is shown. The flexible carrier 10 has several arrayed receiving cavities 100 for housing the piezoelectric array elements 20, ensuring that each piezoelectric array element 20 is independent and preventing crosstalk interference between them. Figure 1As shown, the accommodating cavities 100 are arranged in a ring array, with at least two ring arrays, i.e., at least two ring arrays, arranged sequentially in the radial direction with the same center point. The "ring array" can be circular or rectangular, and is not limited to the illustration. The piezoelectric elements 20 located within the flexible carrier 10 are also arranged in a ring array, with the same number of array groups as the accommodating cavities 100. Here, the number of array groups for the piezoelectric elements 20 is set to N, and N≥2. In this embodiment, several accommodating cavities 100 are arranged in six concentric ring arrays. Similarly, the number of array groups for the piezoelectric elements 20 is also six.

[0055] See Figure 6 As shown, Figure 6 It shows Figure 3 A schematic diagram of the structure of region A. Each piezoelectric element 20 located within the flexible carrier 10 has a positive electrode layer 230 on its back side, capable of forming a voltage difference with the ground electrode layer 50. Element electrode leads 210 extending towards the flexible signal conduction layer 30 are located on the back side of the positive electrode layer 230. The element electrode leads 210 are electrically connected to the flexible circuit board 40 through the flexible signal conduction layer 30, enabling the piezoelectric element 20 to be electrically connected to external circuitry via the flexible circuit board 40. Combined with... Figure 4 As shown, corresponding to the placement positions of the piezoelectric array element 20 and the array element electrode lead 210, the receiving cavity 100 penetrates the front and back of the flexible carrier 10, including a first receiving area 110 and a second receiving area 120 that are interconnected. The piezoelectric array element 20 is disposed in the first receiving area 110, and the end of the array element electrode lead 210 facing away from the piezoelectric array element 20 passes through the second receiving area 120 and is connected to the flexible signal transmission layer 30.

[0056] In this embodiment, the number of flexible signal conduction layers 30 is equal to the number of array groups N of piezoelectric array elements 20, and a flexible circuit board 40 is provided on the back of each flexible signal conduction layer 30. Here, the number of flexible signal conduction layers 30 is set to N. S For example, in this embodiment, the piezoelectric array 20 has six array groups, and the flexible signal conduction layer 30 is set to six layers, all of which have the same radial dimension. Six flexible circuit boards 40 are also provided, each stacked on the central region of the back side of the corresponding flexible signal conduction layer 30. This can be combined with... Figure 6As shown, flexible signal conduction layers 30 and flexible circuit boards 40 are alternately stacked on the back of the flexible carrier 10. Each flexible signal conduction layer 30 electrically connects the element electrode leads 210 on the corresponding group of piezoelectric elements 20 to the flexible circuit board 40 on its back. Each group of piezoelectric elements 20 can be connected to an external circuit through its corresponding flexible signal conduction layer 30 and the flexible circuit board 40 of that layer. This one-to-one pairing arrangement allows the signal transmission between each group of piezoelectric elements 20 and the external circuit to be relatively independent, without interference, and also facilitates rapid troubleshooting. On the other hand, if the signal transmission between one group of piezoelectric elements 20 and the external circuit is unstable, it will not affect the operation of other groups. The following text will further explain in detail how the piezoelectric elements 20 are electrically connected to the flexible circuit board 40 through their corresponding flexible signal conduction layers 30.

[0057] See Figure 6 As shown, each flexible signal conduction layer 30 has multiple conductive channels 31 formed on it. The conductive channels 31 are located on the back side of the flexible signal conduction layer 30, and their length direction is in the radial direction of the flexible signal conduction layer 30. The array element electrode leads 210 are electrically conductive through the conductive channels 31 on the flexible signal conduction layer 30. Specifically, the proximal end of the conductive channel 31 on the Nth flexible signal conduction layer 30 is connected to the flexible circuit board 40 of that layer, and its distal end is connected to the array element electrode leads 210 on the Nth group of piezoelectric array elements 20. "Proximal end" refers to the end near the center point of the flexible signal conduction layer 30, and "distal end" refers to the end away from the center point of the flexible signal conduction layer 30. The "proximal end" and "distal end" in the following text also follow this definition. In this embodiment, the conductive channel 31 is obtained by pouring liquid conductive material into a narrow groove at the corresponding position on the flexible signal conduction layer 30 and cooling it. Compared to directly setting solid conductive channels on the flexible signal transmission layer 30, this method achieves a higher degree of integration with the flexible signal transmission layer 30, better adaptability, superior conductivity stability, and is more suitable for applications subject to repeated deformation. Furthermore, it has a wider range of applications. For example, when the test temperature is below the melting temperature of the conductive material, the conductive channel 31 is solid; when the test temperature is slightly above the melting temperature of the conductive material, the conductive channel 31 can exist in a state between solid and liquid, making it more adaptable to deformation of the ultrasonic transducer. Moreover, by setting multiple layers of flexible signal transmission layers 30 and providing the conductive channel 31 on each layer, the overall strength of the ultrasonic transducer can be enhanced without making it too flexible.

[0058] Continue reading Figure 6As shown, corresponding to the location of the conductive channel 31, an electrode lead via 301 is formed on the flexible signal conduction layer 30, located at the far end of the conductive channel 31. The end of the array element electrode lead 210 furthest from the piezoelectric array element 20 is inserted into the electrode lead via 301 and connected to the far end of the conductive channel 31. Depending on the matrix group in which the array element electrode lead 210 is located, the length of the conductive channel 31 on each flexible signal conduction layer 30 is different to match the corresponding array element electrode lead 210. The following further describes how the multilayer flexible signal conduction layer 30 is configured with electrode lead vias 301 to connect the array element electrode lead 210 of the corresponding array group to the far end of the conductive channel 31. Arranging the piezoelectric array elements 20 in an array form, compared to arranging them in a discrete form, can avoid the conductive channels 31 between the signal transmission layers 30 intersecting on the projection of the ultrasonic transducer thickness direction, so that the electrode leads 210 of the same array element can be electrically connected to the conductive channels 31 on different layers at the same time.

[0059] See Figure 7 and Figure 8 As shown, Figure 7 and Figure 8 The exploded view of the ultrasonic transducer at different angles is shown below. For ease of understanding, the above description is still used. Figure 1 The front and back sides defined herein refer to the directions of description and display. Figure 6 The piezoelectric element 20 is obscured and not shown. To facilitate observation of the correspondence between the element electrode leads 210 and the flexible signal transmission layer 30, Figure 7 and Figure 8 In this case, the array element electrode leads 210 are directly connected to the corresponding flexible signal transmission layer 30.

[0060] See Figure 7 As shown, the flexible signal transmission layer 30 includes a first transmission layer 310, a second transmission layer 320, a third transmission layer 330, a fourth transmission layer 340, a fifth transmission layer 350, and a sixth transmission layer 360. These transmission layers are arranged sequentially along the thickness direction of the ultrasonic transducer. This can be combined with... Figure 6 As shown, the extension lengths of the array element electrode leads 210 vary according to the vertical height of each conductive layer, allowing them to pass through different numbers of conductive layers and connect to the conductive channels 31 of the corresponding layers. The number of array groups of electrode lead vias 301 on each flexible signal conductive layer 30 is different; here, the number of array groups of electrode lead vias 301 is denoted as M. The group of electrode lead vias 301 located near the end communicates with the far end of the conductive channel 31. In this embodiment, the number of groups M of electrode lead vias 301 is related to the number of layers N of the flexible signal conductive layer 30. S The following correspondence exists:

[0061] M = N S(max) -(N S -1)

[0062] Where, N S(max) N represents the maximum number of flexible signal transmission layers. In this embodiment, N is... S(max) =6.

[0063] When the number of layers N of the flexible signal transmission layer 30 S When M=3, the number of array groups of electrode lead vias 301 is M=4, that is, there are 4 groups of electrode lead vias 301 on the third conductive layer 330. Figure 9 As shown, Figure 9 A projection view of the third conductive layer 330 is shown. The electrode lead vias 301 at the far and near ends of the conductive channel 31 are connected. The remaining sets of electrode lead vias 301 provide clearance channels for the connection of other array element electrode leads 210 to the corresponding conductive channels 31. When the number of layers N of the flexible signal conductive layer 30... S When M = 6, the number of array groups of electrode lead vias 301 is M = 1, that is, there is one group of electrode lead vias 301 on the sixth conductive layer 360, such as Figure 10 As shown, Figure 10 A projection view of the sixth conductive layer 360 is shown. The sixth conductive layer 360 is located at the top, so only one set of electrode lead vias 301 needs to be provided.

[0064] Continue reading Figure 7 As shown, the flexible circuit board 40 includes a first circuit board 410, a second circuit board 420, a third circuit board 430, a fourth circuit board 440, a fifth circuit board 450, and a sixth circuit board 460. Each flexible circuit board 40 is stacked on the central region of the back side of each flexible signal conduction layer 30. In this embodiment, each flexible circuit board 40 is provided with conductive pins 401 for electrically connecting the flexible circuit board 40 to an external circuit. The conductive pins 401 are located in the central region of the flexible circuit board 40 and extend away from the flexible circuit board 40.

[0065] Similar to the varying extension lengths of the array element electrode leads 210 described above, which allow them to pass through different numbers of conductive layers, the extension lengths of the conductive pins 401 also vary, allowing them to pass through different numbers of conductive layers and connect to external circuits. (Combined with...) Figure 8 As shown, corresponding to the placement position of the conductive needle 401, an external circuit via 303 is provided in the central region of the flexible signal conduction layer 30. The external circuit vias 303 are arranged in a ring array, and their principle is similar to that of the electrode lead vias 301. Here, the number of array groups of external circuit vias 303 is denoted as K. In this embodiment, the number of array groups K of external circuit vias 303 is related to the number of layers N of the flexible signal conduction layer 30. S The following correspondence exists: K = N S -1. Can be combined Figure 9 and Figure 10As shown, the third conductive layer 330 has two sets of external circuit vias 303, and the sixth conductive layer 360 has five sets of external circuit vias 303. In this embodiment, the second circuit board 420, the third circuit board 430, the fourth circuit board 440, the fifth circuit board 450, and the sixth circuit board 460 are all hollow annular structures to avoid interfering with the conductive pin 401. Since the first circuit board 410 does not need to avoid the conductive pin 401, it does not need to be hollow.

[0066] See Figure 9 and Figure 10 As shown, the near end of the conductive channel 31 is provided with an electrically conductive connection point 311, which is used to make electrical connections with the metal solder joints on the flexible circuit board 40. The diameter of the connection point 311 is larger than the diameter of the conductive channel 31, so as to have a larger contact area with the flexible circuit board 40 and improve the connection stability.

[0067] See Figure 1 As shown, the ultrasonic transducer also includes a common electrode 70 disposed on the side and electrically connected to the ground electrode layer 50, so as to connect the piezoelectric element 20 to the external ground.

[0068] The aforementioned ultrasonic transducers are not only applicable to medical diagnosis, but also to other applications, such as defect detection in natural gas pipelines.

[0069] Regarding the structure of the ultrasonic transducer described above, this embodiment also provides a method for manufacturing the ultrasonic transducer, including the following steps:

[0070] 1) Prepare flexible carrier 10.

[0071] The flexible carrier 10 can be fabricated using 3D printing or injection molding. The material used to fabricate the flexible carrier 10 can be rubber, waterborne polyurethane resin, silicone rubber, or polydimethylsiloxane. In this embodiment, polydimethylsiloxane (PDMS) is used as the material for fabricating the flexible carrier 10, as it possesses excellent flexibility. Furthermore, PDMS is transparent, facilitating observation of the fabrication process. (See reference...) Figure 1 , Figure 4 and Figure 5 The prepared flexible carrier 10 has multiple receiving cavities 100 arranged in a two-dimensional array. The receiving cavities 100 are arranged in multiple ring arrays, and the number of array groups N is greater than or equal to 2. In this embodiment, N (max) =6, N (max) This represents the maximum number of array groups.

[0072] 2) Prepare six flexible signal transmission layers 30 respectively.

[0073] The flexible signal conduction layer 30 can be fabricated by 3D printing or injection molding. The radial dimension of the flexible signal conduction layer 30 is the same as that of the flexible carrier 10. The flexible signal conduction layer 30 is also made of polydimethylsiloxane (PDMS) material.

[0074] Combination Figure 9 and Figure 10 Each flexible signal conduction layer 30 has electrode lead vias 301, conductive grooves 302, and external circuit vias 303 formed on it. Both the electrode lead vias 301 and the external circuit vias 303 penetrate the front and back sides of the flexible signal conduction layer 30. The external circuit vias 303 are located in the central region of the flexible signal conduction layer 30. Conductive grooves 31 are formed on the back side of the flexible signal conduction layer 30, with their length direction located radially in the flexible signal conduction layer 30. The proximal end of the conductive groove 31 is close to the external circuit via 303, and the distal end of the conductive groove 31 communicates with the nearest ground electrode lead via 301. The depth of the conductive groove 31 recessed inward from the back side of the flexible signal conduction layer 30 does not exceed half the thickness of the flexible signal conduction layer 30 to avoid reducing the strength of the flexible signal conduction layer 30.

[0075] In other embodiments, a connecting groove 304 is also formed on the back side of each flexible signal conducting layer 30, and the connecting groove 304 communicates with the proximal end of the conductive groove 31. The depth of the connecting groove 304 recessed inward from the back side of the flexible signal conducting layer 30 does not exceed half the thickness of the flexible signal conducting layer 30.

[0076] 3) Prepare six flexible circuit boards 40.

[0077] Metal solder joints are distributed on the flexible circuit board 40.

[0078] 4) Liquid conductive material is filled into the conductive grooves 31 and connecting grooves 304 of the first conductive layer 310. Before the conductive material cures, the first circuit board 410 is stacked on the back side of the flexible signal conductive layer 30, and the metal solder joints on the flexible circuit board 40 are at least partially accommodated in the connecting grooves 304. After the conductive material cures, conductive pins 401 are provided on the back side of the first circuit board 410 to form a first bonding layer.

[0079] After the conductive material solidifies, the conductive material in the conductive groove 31 forms the conductive channel 31 described above, and the conductive channel 31 is electrically connected to the metal solder joint. By using the process of forming the conductive channel 31 after the molten conductive material solidifies, the conductive channel 31 in the finished product can be tightly bonded to the conductive layer and will not easily detach.

[0080] The metal solder joint is bonded to an uncured conductive material, allowing the uncured conductive material to fully corrode the metal solder joint to achieve a stable bond.

[0081] Furthermore, before placing the flexible circuit board 40 on the flexible signal transmission layer 30, a thin layer of liquid PDMS is coated on the area of ​​the flexible circuit board 40 other than the metal solder joints to bond the flexible signal transmission layer 30 and the flexible circuit board 40.

[0082] Conductive materials are made of metals with high melting points, such as bismuth-based metal alloys.

[0083] 5) Following step 4), sequentially fabricate the second bonding layer consisting of the second conductive layer 320 and the second circuit board 420, the third bonding layer consisting of the third conductive layer 330 and the third circuit board 430, the fourth bonding layer consisting of the fourth conductive layer 340 and the fourth circuit board 440, the fifth bonding layer consisting of the fifth conductive layer 350 and the fifth circuit board 450, and the sixth bonding layer consisting of the sixth conductive layer 360 and the sixth circuit board 460.

[0084] 6) Stack the first bonding layer, the second bonding layer, the third bonding layer, the fourth bonding layer, the fifth bonding layer and the sixth bonding layer in sequence to form a stack.

[0085] Specifically, with the conductive pins 401 of the first circuit board 410 on the first bonding layer facing upwards, liquid PDMS is coated on the back of the first circuit board 410. Then, the second bonding layer is placed on the conductive channel 31, and the second conductive layer 320 in the second bonding layer is bonded to the first circuit board 410 by PDMS. The conductive pins 401 on the first circuit board 410 extend out through the external circuit vias 303 on the second conductive layer 320 in the second bonding layer. Then, liquid PDMS is coated on the back of the second circuit board 420 in the second bonding layer, and the third bonding layer is stacked on the second circuit board 420. The conductive pins 401 on the second circuit board 420 extend out through the external circuit vias 303 on the third conductive layer 330 in the third bonding layer. This process is repeated until all bonding layers are stacked, and the conductive pins 401 on each flexible circuit board 40 extend out of the stack body through the corresponding external circuit vias 303 to connect with the external circuit.

[0086] It is important to note that during the stacking process, the electrode lead vias 301 on each conductive layer must be aligned vertically and not blocked by PDMS.

[0087] 7) The flexible carrier 10 is stacked on the front side of the first conductive layer 310 in the stack.

[0088] Liquid PDMS is coated on the back of the flexible carrier 10, and the back of the flexible carrier 10 is attached to the front of the first conductive layer 310. The receiving cavity 100 on the flexible carrier 10 is connected to the electrode lead via 301 on the first conductive layer 310 in a one-to-one correspondence.

[0089] 8) Fill the cavity 100 of the flexible carrier 10 with liquid conductive material to form the element electrode leads 210.

[0090] Liquid conductive material is injected into the second accommodating region 120 of the accommodating cavity 100 until the conductive material flows to the far end of the conductive channel 31 and just fills the second accommodating region 120.

[0091] The conductive material used to form the array element electrode leads 210 is an alloy, such as a bismuth-based metal, or a rare metal. Because the array element electrode leads 210 are relatively dense, artifacts may occur during imaging in the ultrasonic transducer. Using alloys or rare metals to prepare the array element electrode leads can avoid this problem.

[0092] 9) Place the piezoelectric array element 20 in the first accommodating area 110 of the accommodating cavity 100 and electrically connect it to the array element electrode lead 210.

[0093] A liquid conductive material is coated on the bottom of the first accommodating region 110 or the back of the piezoelectric element 20. The piezoelectric element 20 is then placed in the first accommodating region 110, and the liquid conductive material is allowed to solidify to form a positive electrode layer 230 on the back of the piezoelectric element 20. At this time, the piezoelectric element can be electrically connected to the conductive channel 31 on the flexible signal transmission layer 30 through the element electrode lead 210, and then electrically connected to the conductive pin 401 on the flexible circuit board 40.

[0094] 10) A ground electrode layer 50 is provided on the front side of the piezoelectric array element 20 to enable the multiple piezoelectric array elements 20 to conduct electricity to each other.

[0095] Furthermore, a flexible ground electrode circuit board 80 is bonded to the sixth conductive layer 360. The flexible ground electrode circuit board 80 is as follows: Figure 7 As shown, a ground wire 81 is provided on the flexible ground electrode circuit board 80. The ground electrode layer 50 is electrically connected to the flexible ground electrode circuit board 80, at which time the ground electrode layer 50 can be electrically connected to the external ground.

[0096] 11) The ultrasonic transducer obtained in 10) is encapsulated with PDMS material.

[0097] The packaged ultrasonic transducer, as a module, can be connected to an external transducer cable connector via conductive pin 401. If the ultrasonic transducer is damaged, only the ultrasonic transducer module needs to be replaced, without having to replace the entire transducer cable, thus saving costs.

[0098] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0099] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An ultrasonic transducer, characterized in that, include: Flexible vehicle; N sets of piezoelectric array elements arranged in a ring array within the flexible carrier, where N≥2; Element electrode leads are respectively provided for the plurality of piezoelectric elements; A ground electrode layer that enables the plurality of piezoelectric array elements to conduct electricity to each other, wherein the ground electrode layer is located on the opposite side of the array element electrode leads; The piezoelectric array elements are sequentially arranged on the flexible carrier in layers N, having the same number of layers as the piezoelectric array elements. S A flexible signal conducting layer, the flexible signal conducting layer having a front side on the electrode lead side of the array element and a back side opposite to the front side, N S ≥2; Flexible circuit boards are respectively configured on the back side of each flexible signal transmission layer; The element electrode leads on the Nth group of piezoelectric elements pass through the Nth group of piezoelectric elements. S The flexible signal transmission layer is electrically connected to the flexible circuit board on the back of the layer.

2. The ultrasonic transducer according to claim 1, characterized in that, It also includes multiple conductive channels disposed on the back side of each flexible signal transmission layer, and each of the array element electrode leads is electrically connected to the flexible circuit board through a corresponding conductive channel.

3. The ultrasonic transducer according to claim 2, characterized in that, The conductive channel is a conductive material that fills and is embedded in a narrow groove in the radial direction of the flexible signal transmission layer.

4. The ultrasonic transducer according to claim 2, characterized in that, It also includes electrode lead vias disposed on each of the flexible signal conduction layers, wherein the array element electrode leads are connected to the far end of the conductive channel through the corresponding electrode lead vias, and the near end of the conductive channel is electrically connected to the flexible circuit board of that layer.

5. The ultrasonic transducer according to claim 4, characterized in that, The electrode lead vias are arranged in a ring array on each flexible signal conduction layer, and the number of array groups M of the electrode lead vias is related to the number of flexible signal conduction layers N. S It has the following relationship: M=N S（max） -(N S -1) Where, N S（max） This represents the maximum number of layers in the flexible signal transmission layer.

6. The ultrasonic transducer according to claim 2, characterized in that, It also includes multiple conductive pins vertically disposed on the back of the multiple flexible circuit boards, wherein the conductive pins of the corresponding layers are electrically connected to the conductive channels one by one.

7. The ultrasonic transducer according to claim 6, characterized in that, The flexible signal transmission layer is provided with external circuit vias for the corresponding conductive needles to pass through.

8. The ultrasonic transducer according to claim 7, characterized in that, The external circuit vias are arranged in a ring array on each flexible signal conduction layer, and the number of array groups K of the external circuit vias is related to the number of flexible signal conduction layers N. S It has the following relationship: K=N S -1。 9. The ultrasonic transducer according to claim 1, characterized in that, The piezoelectric array element has a positive electrode layer on its back side that is connected to the array element electrode leads.

10. A method for manufacturing an ultrasonic transducer, characterized in that, Includes the following steps: Prepare a flexible carrier having multiple receiving cavities arranged in a ring array, wherein the number of ring array groups N≥2; Preparation of N S A flexible signal conduction layer and a corresponding number of flexible circuit boards, wherein each flexible signal conduction layer has interconnected electrode lead vias and conductive grooves, and the flexible circuit board has metal solder joints, N S ≥2; Liquid conductive material is filled into the conductive groove of each flexible signal transmission layer, and then the corresponding flexible circuit board is stacked on the back of the flexible signal transmission layer to form multiple bonding layers. The metal solder joints are accommodated in the conductive groove to bond with the conductive material. After the conductive material is cured, a conductive channel electrically connected to the flexible circuit board is formed. Multiple bonding layers are stacked to form a stack body; The flexible carrier is stacked on the front side of the first flexible signal transmission layer in the stack, and the receiving cavity corresponds one-to-one with the electrode lead via. The cavity is filled with a liquid conductive material, which, after solidification, forms an array electrode lead that electrically connects the conductive channel. The piezoelectric element is placed inside the receiving cavity and electrically connected to the electrode leads of the element.

11. The method for manufacturing an ultrasonic transducer according to claim 10, characterized in that, Each flexible signal transmission layer is also formed with an external circuit via. After forming a conductive channel that electrically connects the flexible circuit board and before forming the stack, the method further includes setting a conductive pin on the back of each flexible circuit board. When stacking the bonding layers to form the stack, the conductive pin passes through the corresponding external circuit via and is exposed to the stack.

12. The method for manufacturing an ultrasonic transducer according to claim 10, characterized in that, It also includes providing a ground electrode layer on the front side of the plurality of piezoelectric elements.

13. The method for manufacturing an ultrasonic transducer according to claim 10, characterized in that, Before placing the piezoelectric array element into the receiving cavity, a positive electrode layer is also provided on the back of the piezoelectric array element or at the bottom of the receiving cavity.

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