An ultrasonic transduction substrate, a preparation method and an ultrasonic transduction device

Abstract

The application discloses an ultrasonic transduction substrate, a preparation method and an ultrasonic transduction device, relates to the technical field of ultrasonic technology, and can improve the elasticity of a vibrating diaphragm of the ultrasonic transduction device, inhibit the risk of diaphragm rupture, improve the reliability of the ultrasonic transduction device, and prolong the service life of the ultrasonic transduction device. The ultrasonic transduction substrate comprises a substrate, a first electrode arranged on one side of the substrate, a first insulating layer arranged on the side, away from the substrate, of the first electrode, a second insulating layer arranged on the side, away from the substrate, of the first insulating layer, a cavity being formed between the side, close to the substrate, of the second insulating layer and the side, away from the substrate, of the first insulating layer, and a second electrode arranged on the side, away from the substrate, of the second insulating layer. The second insulating layer is used for realizing ultrasonic energy conversion through vibration deformation. The side, away from the substrate, of the second insulating layer has a recessed part and / or a protruding part, and / or the side, close to the substrate, of the second insulating layer has a recessed part and / or a protruding part.

Description

Technical Field

[0001] This application relates to the field of ultrasonic technology, and in particular to an ultrasonic transducer substrate, its preparation method, and an ultrasonic transducer device. Background Technology

[0002] Currently, CMUTs (Capacitive Micromechanical Ultrasonic Transducers) are increasingly widely used in imaging. CMUTs are capacitive structures that utilize a vibrating diaphragm within a cavity to achieve ultrasonic transduction applications such as imaging, transmitting and receiving ultrasonic signals. However, the vibrating diaphragm is subject to electrostatic forces and mechanical restoring forces, making it prone to breakage under prolonged operation. This results in poor reliability and a short lifespan for ultrasonic transducers. Summary of the Invention

[0003] This application provides an ultrasonic transducer substrate, a preparation method, and an ultrasonic transducer device, which can improve the elasticity of the vibrating film of the ultrasonic transducer device, suppress the risk of vibrating film breakage, improve the reliability of the ultrasonic transducer device, and extend the service life of the ultrasonic transducer device.

[0004] A first aspect of this application provides an ultrasonic transducer substrate, comprising:

[0005] Base;

[0006] The first electrode is disposed on one side of the substrate;

[0007] A first insulating layer is disposed on the side of the first electrode away from the substrate;

[0008] A second insulating layer is disposed on the side of the first insulating layer away from the substrate, and a cavity is formed between the side of the second insulating layer close to the substrate and the side of the first insulating layer away from the substrate.

[0009] The second electrode is disposed on the side of the second insulating layer away from the substrate;

[0010] The second insulating layer is used to achieve ultrasonic energy conversion through vibration deformation;

[0011] The second insulating layer has a recess and / or a protrusion on the side away from the substrate, and / or the second insulating layer has a recess and / or a protrusion on the side close to the substrate.

[0012] In some embodiments, the second insulating layer is configured to undergo vibrational deformation under the drive of the first and second electrodes; and / or,

[0013] The second insulating layer is designed to vibrate and deform under the influence of received external ultrasonic waves.

[0014] In some embodiments, where the second insulating layer has a first recess on the side away from the substrate and a first protrusion on the side of the second insulating layer near the substrate, the orthographic projection of the first protrusion onto the substrate at least partially covers the orthographic projection of the first recess onto the substrate; and / or,

[0015] In the case where the second insulating layer has a first recess on the side away from the substrate and a second recess on the side of the second insulating layer closer to the substrate, the orthographic projection of the first recess on the substrate and the orthographic projection of the second recess on the substrate do not overlap; and / or,

[0016] When the second insulating layer has a second protrusion on the side away from the substrate and a first protrusion on the side of the second insulating layer close to the substrate, the orthographic projection of the first protrusion on the substrate does not overlap with the orthographic projection of the second protrusion on the substrate.

[0017] In some embodiments, where the orthographic projection of the first protrusion on the substrate at least partially covers the orthographic projection of the first recess on the substrate, the orthographic projection of the first protrusion on the substrate completely covers the orthographic projection of the first recess on the substrate.

[0018] In some embodiments, when the second insulating layer has the first recess on the side away from the substrate and the second insulating layer has the first protrusion on the side near the substrate, the shape of the surface of the first protrusion near the substrate matches the shape of the surface of the first recess away from the substrate covered by the orthographic projection.

[0019] In some embodiments, the second insulating layer includes a first region and a second region, the second region surrounding the first region;

[0020] The recess is provided in the second region; and / or,

[0021] The protrusion is disposed in the second region; and / or,

[0022] The second electrode is disposed in the first region.

[0023] In some embodiments, the shape of the recessed portion projected onto the substrate includes at least one of annular, polygonal, circular, and stripe shapes; and / or,

[0024] The shape of the protrusion projected onto the substrate includes at least one of annular, polygonal, circular, and stripe shapes.

[0025] In some embodiments, the shape of the recess projected onto the substrate includes an annular shape, and when there are multiple recesses, the multiple recesses are arranged in concentric rings; and / or,

[0026] The strip shape includes an arc shape; the shape of the recessed portion projected onto the substrate includes an arc shape; and when there are multiple recessed portions, multiple recessed portions have the same center of curvature; and / or,

[0027] The shape of the orthographic projection of the recessed portion onto the substrate includes circles and polygons, and when there are multiple recessed portions, the multiple recessed portions are arranged in an array; and / or,

[0028] When the shape of the protrusion projected onto the substrate includes a ring, and when there are multiple protrusions, the multiple protrusions are arranged in concentric rings; and / or,

[0029] The strip shape includes an arc shape; the shape of the protrusion projected onto the base includes an arc shape; and when there are multiple protrusions, multiple protrusions have the same center of curvature; and / or,

[0030] The shape of the orthographic projection of the protrusion onto the substrate includes circles and polygons, and when there are multiple protrusions, there are multiple protrusions arranged in an array.

[0031] In some embodiments, where the second insulating layer has a first protrusion on the side near the substrate, the first insulating layer has a third recess on the side away from the substrate, and the shape of the surface of the first protrusion near the substrate matches the shape of the surface of the third recess away from the substrate.

[0032] In some embodiments, the second insulating layer has a first recess on the side away from the substrate and a first protrusion on the side of the second insulating layer close to the substrate, wherein the orthographic projection of the first protrusion on the substrate covers the orthographic projection of the first recess on the substrate, and the shape of the surface of the first recess on the side away from the substrate matches the shape of the surface of the third recess on the side away from the substrate.

[0033] In some embodiments, the ratio of the dimension of the recess in the thickness direction of the second insulating layer to the thickness of the second insulating layer ranges from 4 / 5 to 1 / 5; and / or,

[0034] The ratio of the dimension of the third recess in the thickness direction of the first insulating layer to the thickness of the first insulating layer ranges from 4 / 5 to 1 / 5; and / or,

[0035] The substrate includes glass.

[0036] In some embodiments, multiple vibration units are used, and the cavity corresponds one-to-one with each vibration unit; and / or,

[0037] The cavity corresponds one-to-one with the second electrode.

[0038] In some embodiments, the orthographic projection of the cavity onto the substrate includes at least one of a circle and an ellipse.

[0039] In some embodiments, the ultrasonic transducer substrate further includes:

[0040] Packaging structure;

[0041] The second insulating layer is provided with a via, the via penetrating the second insulating layer;

[0042] The encapsulation structure is disposed within the via, and the encapsulation structure includes a connecting end and an encapsulation end. The connecting end is connected to the side of the first insulating layer away from the substrate, and the encapsulation end covers the side of the via away from the substrate.

[0043] The orthographic projection of the via on the substrate falls within the orthographic projection of the package end on the substrate.

[0044] A second aspect of this application provides a method for fabricating an ultrasonic transducer substrate, used to fabricate an ultrasonic transducer substrate as described in any of the first aspects above, the fabrication method comprising:

[0045] A first electrode is disposed on one side of the substrate;

[0046] A first insulating layer is disposed on the side of the first electrode away from the substrate;

[0047] A sacrificial layer is disposed on the side of the first insulating layer away from the substrate;

[0048] A second insulating layer is provided on the side of the sacrificial layer away from the substrate, wherein the side of the second insulating layer away from the substrate has a recess and / or a protrusion, and / or the side of the second insulating layer close to the substrate has a recess and / or a protrusion.

[0049] A second electrode is disposed on the side of the second insulating layer away from the substrate;

[0050] Before or after the second electrode is applied, the sacrificial layer is removed to create a cavity between the side of the second insulating layer near the substrate and the side of the first insulating layer away from the substrate.

[0051] In some embodiments, when the second insulating layer has a first protrusion on the side near the substrate, the method of providing the second insulating layer on the side of the sacrificial layer away from the substrate further includes:

[0052] A fourth recess is provided on the side of the sacrificial layer away from the substrate, wherein the shape of the surface of the first protrusion near the substrate matches the shape of the surface of the fourth recess away from the substrate.

[0053] In some embodiments, where the second insulating layer has a first recess on the side away from the substrate and a first protrusion on the side of the second insulating layer near the substrate, and the shape of the surface of the first recess on the side away from the substrate matches the shape of the surface of the first protrusion on the side near the substrate, the shape of the surface of the first recess on the side away from the substrate matches the shape of the surface of the fourth recess on the side away from the substrate.

[0054] In some embodiments, when the second insulating layer has a first protrusion on the side near the substrate, the method of providing a sacrificial layer on the side of the first insulating layer away from the substrate further includes:

[0055] A third recess is provided on the side of the first insulating layer away from the substrate, wherein the shape of the surface of the first protrusion near the substrate matches the shape of the surface of the third recess away from the substrate.

[0056] In some embodiments, where the second insulating layer has a first recess on the side away from the substrate and a first protrusion on the side of the second insulating layer near the substrate, and the shape of the surface of the first recess on the side away from the substrate matches the shape of the surface of the first protrusion on the side near the substrate, the shape of the surface of the first recess on the side away from the substrate matches the shape of the surface of the third recess on the side away from the substrate.

[0057] A third aspect of this application provides an ultrasonic transducer, comprising:

[0058] Ultrasonic transducer substrate as described in any of the first aspects above.

[0059] The ultrasonic transducer substrate provided in this application embodiment improves the flexibility of the second insulating layer by providing a recess and / or a protrusion on one side of the second insulating layer. When the second insulating layer vibrates under the action of electrostatic force and mechanical restoring force or under the action of ultrasonic waves, the force acting on the surface of the second insulating layer can form a component along the inclined surface of the recess and / or protrusion, reducing the tensile force on the second insulating layer, reducing the risk of breakage of the second insulating layer, expanding the emission range of the ultrasonic transducer, extending the service life of the ultrasonic transducer substrate, improving the reliability of the ultrasonic transducer, and also expanding the linear relationship range between the magnitude of the force on the second insulating layer and the magnitude of the deformation, thereby improving the detection range and accuracy of the ultrasonic transducer for ultrasonic waves. Attached Figure Description

[0060] Figure 1 A schematic structural diagram of an ultrasonic transducer substrate provided in an embodiment of this application;

[0061] Figure 2 A schematic partial structural diagram of a conventional ultrasonic transducer substrate provided for embodiments of this application;

[0062] Figure 3 A schematic partial structural diagram of an ultrasonic transducer substrate provided in an embodiment of this application;

[0063] Figure 4 A schematic structural diagram of another ultrasonic transducer substrate provided in an embodiment of this application;

[0064] Figure 5 A schematic structural diagram of another ultrasonic transducer substrate provided in the embodiments of this application;

[0065] Figure 6 A schematic structural diagram of another ultrasonic transducer substrate provided in the embodiments of this application;

[0066] Figure 7 A schematic structural diagram of an ultrasonic transducer substrate provided in an embodiment of this application;

[0067] Figure 8 A schematic structural diagram of another ultrasonic transducer substrate provided in an embodiment of this application;

[0068] Figure 9 A schematic top view of an ultrasonic transducer substrate provided for an embodiment of this application;

[0069] Figure 10 A schematic top view of another ultrasonic transducer substrate provided in an embodiment of this application;

[0070] Figure 11A schematic top view of another ultrasonic transducer substrate provided in the embodiments of this application;

[0071] Figure 12 A schematic structural diagram of another ultrasonic transducer substrate provided in the embodiments of this application;

[0072] Figure 13 A schematic structural diagram of another ultrasonic transducer substrate provided in the embodiments of this application;

[0073] Figure 14 A schematic structural diagram of an ultrasonic transducer substrate provided in an embodiment of this application;

[0074] Figure 15 A schematic structural diagram of another ultrasonic transducer substrate provided in an embodiment of this application;

[0075] Figure 16 A schematic structural diagram of another ultrasonic transducer substrate provided in the embodiments of this application;

[0076] Figure 17 A schematic flowchart illustrating a method for fabricating an ultrasonic transducer substrate provided in an embodiment of this application;

[0077] Figure 18 A schematic flowchart illustrating another method for fabricating an ultrasonic transducer substrate provided in an embodiment of this application;

[0078] Figure 19 This application provides a schematic structural diagram of an ultrasonic transducer. Detailed Implementation

[0079] To better understand the technical solutions provided in the embodiments of this specification, the technical solutions of the embodiments of this specification will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this specification and the specific features in the embodiments are detailed descriptions of the technical solutions of the embodiments of this specification, rather than limitations on the technical solutions of this specification. In the absence of conflict, the embodiments of this specification and the technical features in the embodiments can be combined with each other.

[0080] In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, without necessarily requiring or implying any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element. The term "two or more" includes two or more cases.

[0081] Currently, CMUTs are increasingly widely used in imaging. CMUTs are capacitive structures that utilize vibrating thin films within cavities to achieve ultrasonic transduction applications such as imaging, transmitting and receiving ultrasonic signals.

[0082] During the operation of CMUTs, the vibrating diaphragm generates ultrasonic waves within the cavity through vibration, and can also vibrate in response to disturbances in the external ultrasonic environment, generating electrical signals based on the vibration amplitude for ultrasonic wave detection. However, during the vibration of the diaphragm along the thickness direction of the substrate, it is also subjected to tensile forces perpendicular to the substrate thickness direction. This limits the vibration amplitude and makes the diaphragm prone to breakage after excessive stress or prolonged vibration, shortening the lifespan of the ultrasonic transducer. Furthermore, due to the limited elasticity of the diaphragm, under significant stress, the magnitude of the stress and deformation during vibration cannot maintain a linear relationship. This can lead to the CMUTs failing to accurately emit or identify ultrasonic waves, affecting the reliability of the ultrasonic transducer.

[0083] In view of this, the present application provides an ultrasonic transducer substrate, a preparation method, and an ultrasonic transducer device, which can improve the elasticity of the vibrating film of the ultrasonic transducer device, suppress the risk of vibrating film breakage, extend the service life of the ultrasonic transducer device, expand the linear relationship range between the magnitude of the force on the vibrating film and the magnitude of the deformation, and improve the reliability of the ultrasonic transducer device.

[0084] A first aspect of this application provides an ultrasonic transducer substrate. Figure 1 This is a schematic structural diagram of an ultrasonic transducer substrate provided in an embodiment of this application. Figure 1As shown, the ultrasonic transducer substrate may include: a substrate 100, a first electrode 200, a first insulating layer 300, a second insulating layer 400, and a second electrode 500. The first electrode 200 is disposed on one side of the substrate 100; the first insulating layer 300 is disposed on the side of the first electrode 200 away from the substrate 100; the second insulating layer 400 is disposed on the side of the first insulating layer 300 away from the substrate 100, and a cavity 403 is formed between the side of the second insulating layer 400 near the substrate 100 and the side of the first insulating layer 300 away from the substrate 100; the second electrode 500 is disposed on the side of the second insulating layer 400 away from the substrate 100; the second insulating layer 400 is used to achieve ultrasonic energy conversion through vibration deformation; the side of the second insulating layer 400 away from the substrate 100 has a recess 410 and / or a protrusion 420, and / or the side of the second insulating layer 400 near the substrate 100 has a recess 410 and / or a protrusion 420.

[0085] In some examples, the recess 410 may be provided only on the side of the second insulating layer 400 away from the substrate 100.

[0086] In some examples, the recess 410 may be provided only on the side of the second insulating layer 400 near the substrate 100.

[0087] In some examples, the protrusion 420 may be provided only on the side of the second insulating layer 400 away from the substrate 100.

[0088] In some examples, the protrusion 420 may be provided only on the side of the second insulating layer 400 near the substrate 100.

[0089] It should be noted that, along the thickness direction H of the substrate 100, the recessed portions 410 and protrusions 420 located on both sides of the second insulating layer 400 can be arbitrarily combined to form different morphologies of the surfaces on both sides of the second insulating layer 400. These will not be listed one by one here, and the embodiments of this application do not impose specific limitations.

[0090] It should be noted that the cavity 403 can provide a vibration space for the second insulating layer 400. When the second insulating layer 400 vibrates, mechanical energy can be converted into acoustic energy, enabling the ultrasonic transducer to emit ultrasonic waves. When there is a disturbance in the external environment, such as when there is an ultrasonic signal on the side of the second insulating layer 400 away from the substrate 100, acoustic energy can be converted into mechanical energy, causing the second insulating layer 400 to vibrate.

[0091] For example, the first electrode 200 and the second electrode 500 can be one or more metal stacked structures selected from aluminum, molybdenum, copper, gold, titanium, nickel, and silver, such as titanium aluminum titanium and molybdenum aluminum molybdenum.

[0092] For example, Figure 2This is a schematic partial structural diagram of a conventional ultrasonic transducer substrate provided for an embodiment of this application. For example... Figure 2 As shown, the ultrasonic transducer substrate includes: a substrate 100, a first electrode 200, a first insulating layer 300, a second insulating layer 400, a second electrode 500, and an isolation structure 600. A cavity 403 is formed between the first insulating layer 300 and the second insulating layer 400. The isolation structure 600 is disposed between the second insulating layer 400 and the substrate 100 to support the second insulating layer 400. The arrows indicate the vibration direction of the second insulating layer 400, which vibrates along the thickness direction H of the substrate 100. The dashed lines indicate the positions that the second insulating layer 400 can reach during vibration. When the second insulating layer 400 deforms, mechanical restoring forces are generated at both ends of the second insulating layer 400 along the deformation point in the horizontal direction perpendicular to the thickness direction H of the substrate 100. This forces exert tension on the second insulating layer 400, reducing its elasticity and increasing the risk of breakage after prolonged vibration. Furthermore, as the elasticity of the second insulating layer 400 decreases, it may exhibit initial deformation, leading to a reduction in the amplitude of the vibration under stress. This weakens the linear relationship between the magnitude of the stress and the magnitude of the deformation, thus reducing the sound generation and detection performance of the ultrasonic transducer substrate.

[0093] For example, Figure 3 This is a schematic partial structural diagram of an ultrasonic transducer substrate provided in an embodiment of this application. Figure 3As shown, the ultrasonic transducer substrate includes: a substrate 100, a first electrode 200, a first insulating layer 300, a second insulating layer 400, a second electrode 500, and an isolation structure 600. A cavity 403 is formed between the first insulating layer 300 and the second insulating layer 400. The second insulating layer 400 has a recess 410 on the side away from the substrate 100. When the second insulating layer 400 is subjected to electrostatic force or external disturbance, the surface of the recess 410 of the second insulating layer 400 is subjected to pressure F. The pressure F forms a first component F1 and a second component F2 in the tangential direction and the normal direction at the point of force application of the second insulating layer 400, respectively. When the surface of the second insulating layer 400 deforms under pressure F, the first component F1 in the tangential direction at the point of force application of the second insulating layer 400 is smaller than the pressure F directly acting on the point of force application compared to a smooth surface. A second component F2 can also be formed in the normal direction at the point of force application of the second insulating layer 400. This balances at least part of the mechanical restoring force generated by both ends of the second insulating layer 400 on the point of force application, thus reducing the risk of fracture of the second insulating layer 400, improving the reliability of the ultrasonic transducer, and extending its service life. Furthermore, when the surface of the recessed portion 410 of the second insulating layer 400 is subjected to a large pressure F, the pressure F has a smaller impact on the elasticity of the second insulating layer 400, maintaining a linear relationship between the magnitude of the force and the magnitude of the deformation. This expands the detection range and sound emission range of the ultrasonic transducer, improving its accuracy and sensitivity.

[0094] The ultrasonic transducer substrate provided in this application embodiment, by providing a recess 410 and / or a protrusion 420 on one side of the second insulating layer 400, can improve the flexibility of the second insulating layer 400. When the second insulating layer 400 vibrates under the action of electrostatic force and mechanical restoring force or under the action of ultrasonic waves, the force acting on the surface of the second insulating layer 400 can form a component along the inclined surface of the recess 410 and / or the protrusion 420, reducing the tensile force on the second insulating layer 400, reducing the risk of breakage of the second insulating layer 400, expanding the emission range of the ultrasonic transducer, extending the service life of the ultrasonic transducer substrate, improving the reliability of the ultrasonic transducer, and also expanding the linear relationship range between the magnitude of the force on the second insulating layer 400 and the magnitude of the deformation, improving the detection range and accuracy of the ultrasonic transducer for ultrasonic waves.

[0095] In some feasible implementations, the second insulating layer 400 is used to undergo vibrational deformation under the drive of the first electrode 200 and the second electrode 500.

[0096] For example, Figure 4 This is a schematic structural diagram of another ultrasonic transducer substrate provided in an embodiment of this application. Figure 4As shown, the ultrasonic transducer substrate includes: a substrate 100, a first electrode 200, a first insulating layer 300, a second insulating layer 400, and a second electrode 500, with a cavity 403 formed between the first insulating layer 300 and the second insulating layer 400. A certain DC bias voltage and AC excitation signal are applied between the first electrode 200 and the second electrode 500 using an AC power supply, and the first electrode 200 is grounded.

[0097] It should be noted that when the ultrasonic transducer is in the sound-generating state, the conversion of electrical energy into mechanical energy can be achieved by superimposing the DC bias voltage and the AC excitation signal, so that the second insulating layer 400 can generate simple harmonic motion under the AC excitation signal, thus generating ultrasonic waves.

[0098] In some feasible implementations, the second insulating layer 400 is used to vibrate and deform under the influence of received external ultrasonic waves.

[0099] For example, Figure 5 This is a schematic structural diagram of another ultrasonic transducer substrate provided in an embodiment of this application. (See diagram below.) Figure 4 As shown, the ultrasonic transducer substrate includes: a substrate 100, a first electrode 200, a first insulating layer 300, a second insulating layer 400, and a second electrode 500, with a cavity 403 formed between the first insulating layer 300 and the second insulating layer 400. A certain DC bias voltage is applied between the first electrode 200 and the second electrode 500 by a DC power supply, and the first electrode 200 is grounded.

[0100] It should be noted that when the ultrasonic transducer is in detection mode, the second insulating layer 400 vibrates under the disturbance of the external ultrasonic environment, realizing the conversion of acoustic energy into mechanical energy. This changes the distance between the first electrode 200 and the second electrode 500, thereby changing the capacitance between them. The change in capacitance is amplified and output by an amplifier. By detecting the change in the output capacitance, ultrasonic waves can be detected, thus realizing the conversion of mechanical energy into electrical energy.

[0101] In some feasible embodiments, when the second insulating layer 400 has a first recess on the side away from the substrate 100 and a first protrusion on the side of the second insulating layer 400 close to the substrate 100, the orthographic projection of the first protrusion on the substrate 100 at least partially covers the orthographic projection of the first recess on the substrate 100.

[0102] refer to Figure 4 The ultrasonic transducer substrate includes a first recess 411 and a first protrusion 421. The orthographic projection of the first protrusion 421 on the substrate 100 at least partially covers the orthographic projection of the first recess 411 on the substrate 100.

[0103] It should be noted that by providing a first protrusion 421 on the side of the second insulating layer 400 close to the substrate 100, the thickness of the second insulating layer 400 can be increased, preventing the second insulating layer 400 from breaking.

[0104] The ultrasonic transducer substrate provided in this application embodiment allows the force acting on the second insulating layer 400 to form a component through the first recess 411, and further enhance the flexibility of the second insulating layer 400 through the first protrusion 421, preventing the second insulating layer 400 corresponding to the first recess 411 from being too thin, thereby reducing the risk of breakage of the second insulating layer 400, extending the service life of the ultrasonic transducer substrate, and improving the reliability of the ultrasonic transducer device.

[0105] In some feasible embodiments, when the second insulating layer 400 has a first recess 411 on the side away from the substrate 100 and a second recess on the side of the second insulating layer 400 close to the substrate 100, the orthographic projection of the first recess 411 on the substrate 100 does not overlap with the orthographic projection of the second recess on the substrate 100.

[0106] For example, Figure 6 This is a schematic structural diagram of another ultrasonic transducer substrate provided in an embodiment of this application. (See diagram below.) Figure 6 As shown, the ultrasonic transducer substrate includes: a substrate 100, a first electrode 200, a first insulating layer 300, a second insulating layer 400, and a second electrode 500. A cavity 403 is formed between the first insulating layer 300 and the second insulating layer 400. The side of the second insulating layer 400 away from the substrate 100 has a first recess 411, and the side of the second insulating layer 400 closer to the substrate 100 has a second recess 412. The orthographic projections of the first recess 411 and the second recess 412 on the substrate 100 do not overlap.

[0107] It should be noted that when the first recess 411 and the second recess 412 are simultaneously provided on both sides of the second insulating layer 400, and the orthographic projection of the first recess 411 on the substrate 100 overlaps with the orthographic projection of the second recess 412 on the substrate 100, at least part of the second insulating layer 400 will be too thin and will easily break during vibration.

[0108] The ultrasonic transducer substrate provided in this application embodiment can prevent the second insulating layer 400 from breaking due to excessive thinness. It can also make the second insulating layer 400 between adjacent first recess 411 and second recess 412 form a spring-like structure, thereby improving the elasticity and ductility of the second insulating layer 400, further preventing the second insulating layer 400 from breaking, extending the service life of the ultrasonic transducer substrate, and expanding the linear relationship range between the magnitude of the force on the second insulating layer 400 and the magnitude of the deformation, thereby improving the detection range and accuracy of the ultrasonic transducer for ultrasonic waves.

[0109] In some feasible embodiments, when the second insulating layer 400 has a second protrusion on the side away from the substrate 100 and a first protrusion 421 on the side of the second insulating layer 400 close to the substrate 100, the orthographic projection of the first protrusion 421 on the substrate 100 does not overlap with the orthographic projection of the second protrusion on the substrate 100.

[0110] For example, Figure 7 This is a schematic structural diagram of an ultrasonic transducer substrate provided in an embodiment of this application. Figure 7 As shown, the ultrasonic transducer substrate includes: a substrate 100, a first electrode 200, a first insulating layer 300, a second insulating layer 400, and a second electrode 500. A cavity 403 is formed between the first insulating layer 300 and the second insulating layer 400. The second insulating layer 400 has a first protrusion 421 on the side near the substrate 100 and a second protrusion 422 on the side away from the substrate 100. The orthographic projections of the first protrusion 421 and the second protrusion 422 on the substrate 100 do not overlap.

[0111] It should be noted that when the first protrusion 421 and the second protrusion 422 are simultaneously disposed on both sides of the second insulating layer 400, and the orthographic projection of the first protrusion 421 on the substrate 100 overlaps with the orthographic projection of the second protrusion 422 on the substrate 100, at least part of the second insulating layer 400 will be too thick, making it difficult to be disturbed by the external ultrasonic environment and electrostatic force. This results in uneven vibration amplitude at various points on the second insulating layer 400, which increases the risk of breakage of the second insulating layer 400 and worsens the linear relationship between the magnitude of the force on the second insulating layer 400 and the magnitude of the deformation.

[0112] The ultrasonic transducer substrate provided in this application embodiment can avoid excessive thickness differences in various parts of the second insulating layer 400, allowing the second insulating layer 400 to vibrate under relatively small ultrasonic disturbances or electrostatic forces. This expands the detection range and sound emission range of the ultrasonic transducer, avoids uneven vibration amplitude in various parts of the second insulating layer 400, reduces the risk of breakage of the second insulating layer 400, expands the linear relationship range between the magnitude of the force on the second insulating layer 400 and the magnitude of the deformation, extends the service life of the ultrasonic transducer substrate, and improves the detection range and accuracy of the ultrasonic transducer for ultrasonic waves.

[0113] For example, Figure 8 This is a schematic structural diagram of another ultrasonic transducer substrate provided in an embodiment of this application. Figure 8 As shown, the ultrasonic transducer substrate includes: a substrate 100, a first electrode 200, a first insulating layer 300, a second insulating layer 400, and a second electrode 500. A cavity 403 is formed between the first insulating layer 300 and the second insulating layer 400. The second insulating layer 400 has a second recess 412 on the side near the substrate 100 and a second protrusion 422 on the side away from the substrate 100. The orthographic projection of the second protrusion 422 on the substrate 100 at least partially covers the orthographic projection of the second recess 412 on the substrate 100.

[0114] The ultrasonic transducer substrate provided in this application embodiment allows the force acting on the second insulating layer 400 to form a component through the second protrusion 422, and further thin the second insulating layer 400 through the second recess 412. This avoids excessive thickness differences across the second insulating layer 400, enabling the second insulating layer 400 to vibrate under relatively small ultrasonic disturbances or electrostatic forces. This expands the detection and sound emission range of the ultrasonic transducer, avoids uneven vibration amplitude across the second insulating layer 400, reduces the risk of breakage of the second insulating layer 400, expands the linear relationship between the magnitude of the force on the second insulating layer 400 and the magnitude of the deformation, extends the service life of the ultrasonic transducer substrate, improves the detection range and accuracy of the ultrasonic transducer, and enhances the reliability of the ultrasonic transducer.

[0115] In some feasible embodiments, where the orthographic projection of the first protrusion 421 on the base 100 at least partially covers the orthographic projection of the first recess 411 on the base 100, the orthographic projection of the first protrusion 421 on the base 100 completely covers the orthographic projection of the first recess 411 on the base 100.

[0116] refer to Figure 4This can further improve the uniformity of the thickness of the second insulating layer 400, making the first protrusion 421 correspond one-to-one with the first recess 411, forming a structure similar to a spring. This enhances the supporting effect of the first protrusion 421 on the first recess 411, increases the surface area of ​​the second insulating layer 400, thereby improving the elasticity and ductility of the second insulating layer 400, expanding the linear relationship between the magnitude of the force on the second insulating layer 400 and the magnitude of the deformation, improving the detection range and accuracy of the ultrasonic transducer for ultrasonic waves, further reducing the risk of breakage of the second insulating layer 400, extending the service life of the ultrasonic transducer substrate, and improving the reliability of the ultrasonic transducer.

[0117] In some feasible embodiments, when the second insulating layer 400 has a first recess 411 on the side away from the substrate 100 and a first protrusion 421 on the side of the second insulating layer 400 near the substrate 100, the shape of the surface of the first protrusion 421 near the substrate 100 matches the shape of the surface of the first recess 411 away from the substrate 100 covered by the orthographic projection.

[0118] It should be noted that "shape matching" means that the shape of the surface away from the substrate 100 can be prepared according to the shape of the surface near the substrate 100, or the shape of the surface near the substrate 100 can be prepared according to the shape of the surface away from the substrate 100.

[0119] For example, when the shape of the surface of the first recess 411 away from the substrate 100 is conformally formed according to the shape of the surface of the first protrusion 421 near the substrate 100, a recessed structure matching the first protrusion 421 can be first formed between the second insulating layer 400 and the substrate 100. Then, the second insulating layer 400 is provided on the side of the recessed structure away from the substrate 100, so that part of the second insulating layer 400 falls into the recessed structure, and the first protrusion 421 and the first recess 411 are formed simultaneously. When the shape of the surface near the substrate 100 is conformally formed according to the shape of the surface away from the substrate 100, a flat second insulating layer 400 can be first formed. The first recess 411 can be pressed into the side of the second insulating layer 400 away from the substrate 100 by a pressing process. At the same time, as the second insulating layer 400 deforms, the first protrusion 421 is correspondingly formed on the side of the second insulating layer 400 near the substrate 100.

[0120] The ultrasonic transducer substrate provided in this application embodiment can reduce the difficulty of correspondingly setting the first recess 411 and the first protrusion 421, and form an approximate spring structure in the second insulating layer 400. This can improve the elasticity and ductility of the second insulating layer 400, expand the linear relationship range between the magnitude of the force on the second insulating layer 400 and the magnitude of the deformation, improve the detection range and accuracy of the ultrasonic transducer for ultrasonic waves, further reduce the risk of breakage of the second insulating layer 400, extend the service life of the ultrasonic transducer substrate, and improve the reliability of the ultrasonic transducer.

[0121] In some feasible embodiments, the second insulating layer 400 includes a first region and a second region, the second region surrounding the first region; and a recess 410 is disposed in the second region.

[0122] refer to Figure 4 The second insulating layer 400 includes a first region 401 and a second region 402.

[0123] The ultrasonic transducer substrate provided in this application embodiment allows the recessed portion 410 to be disposed around the first region 401, so as to improve the flexibility of the second insulating layer 400 in the second region 402, expand the vibration range of the second insulating layer 400, facilitate the improvement of the ultrasonic receiving area and ultrasonic transmitting area of ​​the ultrasonic transducer, and improve the detection range and sound emission capability of the ultrasonic transducer.

[0124] The ultrasonic transducer substrate provided in this application embodiment, by providing a recess 410 and / or a protrusion 420 on one side of the second insulating layer 400, can improve the flexibility of the second insulating layer 400. When the second insulating layer 400 vibrates under the action of electrostatic force and mechanical restoring force or under the action of ultrasonic waves, the force acting on the surface of the second insulating layer 400 can form a component along the inclined surface of the recess 410 and / or the protrusion 420, reducing the tensile force on the second insulating layer 400, reducing the risk of breakage of the second insulating layer 400, expanding the emission range of the ultrasonic transducer, extending the service life of the ultrasonic transducer substrate, improving the reliability of the ultrasonic transducer, and also expanding the linear relationship range between the magnitude of the force on the second insulating layer 400 and the magnitude of the deformation, improving the detection range and accuracy of the ultrasonic transducer for ultrasonic waves.

[0125] In some feasible implementations, the protrusion 420 is provided in the second region 402.

[0126] The ultrasonic transducer substrate provided in this application embodiment allows the protrusion 420 to be disposed around the first region 401, so as to improve the flexibility of the second insulating layer 400 in the second region 402, expand the vibration range of the second insulating layer 400, facilitate the improvement of the ultrasonic receiving area and ultrasonic transmitting area of ​​the ultrasonic transducer, and improve the detection range and sound emission capability of the ultrasonic transducer.

[0127] In some feasible implementations, the second electrode 500 is disposed in the first region 401.

[0128] The ultrasonic transducer substrate provided in this application embodiment can improve the driving effect of the electrostatic force of the second electrode 500 on the vibration of the second insulating layer 400 by disposing the second electrode 500 in the central region of the second insulating layer 400, and can also improve the collection capability of the second electrode 500 on the vibration of the second insulating layer 400, thereby improving the accuracy and sensitivity of the ultrasonic transducer device in detection and sound generation.

[0129] In some feasible embodiments, the shape of the recess 410 projected onto the substrate 100 includes at least one of annular, polygonal, circular, and strip-shaped.

[0130] For example, Figure 9 This is a schematic top view of an ultrasonic transducer substrate provided as an embodiment of this application. Figure 9 As shown, the ultrasonic transducer substrate includes: a second insulating layer 400, a recess 410, a second electrode 500, and a packaging structure 700. The recess 410, when projected onto the substrate 100, has a ring-shaped profile.

[0131] For example, Figure 10 A schematic top view of another ultrasonic transducer substrate provided in an embodiment of this application. (See attached image.) Figure 10 As shown, the ultrasonic transducer substrate includes: a second insulating layer 400, a recess 410, a second electrode 500, and an encapsulation structure 700. The recess 410, when projected onto the substrate 100, has a strip-shaped form.

[0132] For example, Figure 11 This is a schematic top view of yet another ultrasonic transducer substrate provided in an embodiment of this application. (See attached image.) Figure 11 As shown, the ultrasonic transducer substrate includes: a second insulating layer 400, a recess 410, a second electrode 500, and a packaging structure 700. The recess 410, when projected onto the substrate 100, has a polygonal shape.

[0133] The ultrasonic transducer substrate provided in this application embodiment, by providing a recessed portion 410 on one side of the second insulating layer 400, can improve the flexibility of the second insulating layer 400. When the second insulating layer 400 vibrates under the action of electrostatic force and mechanical restoring force or under the action of ultrasonic waves, the force acting on the surface of the second insulating layer 400 can form a component along the inclined surface of the recessed portion 410, reducing the tensile force on the second insulating layer 400, reducing the risk of breakage of the second insulating layer 400, expanding the emission range of the ultrasonic transducer, extending the service life of the ultrasonic transducer substrate, improving the reliability of the ultrasonic transducer, and also expanding the linear relationship range between the magnitude of the force on the second insulating layer 400 and the magnitude of the deformation, thereby improving the detection range and accuracy of the ultrasonic transducer for ultrasonic waves.

[0134] In some feasible implementations, the shape of the protrusion projected onto the base 100 includes at least one of annular, polygonal, circular, and stripe shapes.

[0135] The ultrasonic transducer substrate provided in this application embodiment improves the flexibility of the second insulating layer 400 by providing a protrusion 420 on one side of the second insulating layer 400. When the second insulating layer 400 vibrates under the action of electrostatic force and mechanical restoring force or under the action of ultrasonic waves, the force acting on the surface of the second insulating layer 400 can form a component along the inclined surface of the protrusion 420, reducing the tensile force on the second insulating layer 400, reducing the risk of breakage of the second insulating layer 400, expanding the emission range of the ultrasonic transducer, extending the service life of the ultrasonic transducer substrate, improving the reliability of the ultrasonic transducer, and also expanding the linear relationship range between the magnitude of the force on the second insulating layer 400 and the magnitude of the deformation, thereby improving the detection range and accuracy of the ultrasonic transducer for ultrasonic waves.

[0136] In some feasible embodiments, when the shape of the recess 410 projected onto the substrate 100 includes an annular shape, and when there are multiple recesses 410, there are multiple recesses 410 arranged in concentric rings.

[0137] refer to Figure 9 Multiple recesses 410 are arranged in concentric rings.

[0138] For example, the distance between adjacent annular recesses 410 is equal.

[0139] The ultrasonic transducer substrate provided in this application embodiment can increase the occupied area of ​​the recessed portion 410 on the second insulating layer 400, thereby further improving the force component effect of the recessed portion 410 on the surface of the second insulating layer 400, further reducing the tensile force on the second insulating layer 400, reducing the risk of breakage of the second insulating layer 400, extending the service life of the ultrasonic transducer substrate, and improving the reliability of the ultrasonic transducer device.

[0140] In some feasible implementations, the strip shape includes an arc shape, the shape of the recess 410 projected onto the substrate 100 includes an arc shape, and when there are multiple recesses 410, there are multiple recesses 410 with the same center of curvature.

[0141] refer to Figure 10 The curvature center points of the multiple recesses 410 are the same, and the curvature center point is the center of the second electrode 500. It should be noted that the orthographic projection of the arc-shaped recesses 410 onto the substrate 100 is an arc formed with the curvature center point as the center.

[0142] The ultrasonic transducer substrate provided in this application embodiment can reduce the area occupied by the recess 410 on the second insulating layer 400, thereby avoiding the situation where the area occupied by the recess 410 is too large or the distance is too close, resulting in a small flat surface of the second insulating layer 400. The tensile force on the recess 410 may cause the flat surface to break, thereby further reducing the risk of breakage of the second insulating layer 400, extending the service life of the ultrasonic transducer substrate, and improving the reliability of the ultrasonic transducer device.

[0143] In some feasible embodiments, the shape of the orthographic projection of the recess 410 onto the substrate 100 includes circles and polygons, and when there are multiple recesses 410, there are multiple recesses arranged in an array.

[0144] refer to Figure 11 The shape of the orthographic projection of the plurality of recesses 410 on the substrate 100 includes polygons, and the plurality of recesses 410 are arranged in an array.

[0145] The ultrasonic transducer substrate provided in this application embodiment can improve the uniformity of force on each recess 410 and reduce the influence of the tension between each recess 410 on vibration, thereby improving the accuracy of ultrasonic transducer detection and sound generation.

[0146] In some feasible embodiments, when the shape of the protrusion 420 projected onto the base 100 includes an annular shape, and when there are multiple protrusions 420, there are multiple protrusions 420 arranged in concentric rings.

[0147] The ultrasonic transducer substrate provided in this application embodiment can increase the area occupied by the protrusion 420 on the second insulating layer 400, thereby further improving the force component effect of the protrusion 420 on the surface of the second insulating layer 400, further reducing the tensile force on the second insulating layer 400, reducing the risk of breakage of the second insulating layer 400, extending the service life of the ultrasonic transducer substrate, and improving the reliability of the ultrasonic transducer device.

[0148] In some feasible implementations, the strip shape includes an arc shape, the shape of the protrusion projected onto the base 100 includes an arc shape, and when there are multiple protrusions, the curvature center points of multiple protrusions are the same.

[0149] The ultrasonic transducer substrate provided in this application embodiment can reduce the area occupied by the protrusions 420 on the second insulating layer 400, thereby avoiding the protrusions 420 occupying too large an area or being too close together, resulting in a small flat surface of the second insulating layer 400, and the tensile force on the protrusions 420 causing the flat surface to break. This can further reduce the risk of breakage of the second insulating layer 400, extend the service life of the ultrasonic transducer substrate, and improve the reliability of the ultrasonic transducer device.

[0150] In some feasible implementations, the shape of the orthographic projection of the protrusion onto the base 100 includes circles and polygons, and when there are multiple protrusions, there are multiple protrusions arranged in an array.

[0151] The ultrasonic transducer substrate provided in this application embodiment can improve the uniformity of force on each protrusion 420 and reduce the influence of the tension between each protrusion 420 on vibration, thereby improving the accuracy of ultrasonic transducer detection and sound generation.

[0152] In some feasible embodiments, when the second insulating layer 400 has a first protrusion 421 on the side near the substrate 100, the first insulating layer 300 has a third recess on the side away from the substrate 100, and the shape of the surface of the first protrusion 421 near the substrate 100 matches the shape of the surface of the third recess away from the substrate 100.

[0153] For example, Figure 12 This is a schematic structural diagram of another ultrasonic transducer substrate provided in an embodiment of this application. (See diagram below.) Figure 12 As shown, the ultrasonic transducer substrate includes: a substrate 100, a first electrode 200, a first insulating layer 300, a second insulating layer 400, and a second electrode 500. A cavity 403 is formed between the first insulating layer 300 and the second insulating layer 400. The second insulating layer 400 has a first protrusion 421 on the side near the substrate 100 and a third recess 430 on the side of the first insulating layer 300 away from the substrate 100.

[0154] The ultrasonic transducer substrate provided in this application embodiment facilitates the second insulating layer 400 to form a first protrusion 421 conformally to the third recess 430, thereby increasing the thickness of the surface of the second insulating layer 400 near the substrate 100, improving the strength of the second insulating layer 400, preventing the second insulating layer 400 from vibrating and breaking, further reducing the risk of breakage of the second insulating layer 400, extending the service life of the ultrasonic transducer substrate, and improving the reliability of the ultrasonic transducer device.

[0155] In some feasible embodiments, the second insulating layer 400 has a first recess 411 on the side away from the substrate 100 and a first protrusion 421 on the side of the second insulating layer 400 close to the substrate 100, and the orthographic projection of the first protrusion 421 on the substrate 100 covers the orthographic projection of the first recess 411 on the substrate 100, and the shape of the surface of the first recess 411 away from the substrate 100 matches the shape of the surface of the third recess 430 away from the substrate 100.

[0156] For example, Figure 13 This is a schematic structural diagram of another ultrasonic transducer substrate provided in an embodiment of this application. (See diagram below.) Figure 13 As shown, the ultrasonic transducer substrate includes: a substrate 100, a first electrode 200, a first insulating layer 300, a second insulating layer 400, and a second electrode 500. A cavity 403 is formed between the first insulating layer 300 and the second insulating layer 400. The second insulating layer 400 has a first protrusion 421 on the side near the substrate 100, a third recess 430 on the side away from the substrate 100, and a first recess 411 on the side away from the substrate 100.

[0157] For example, a transition structure can be formed conformally on the side of the third recess 430 away from the substrate 100, and a second insulating layer 400 can be formed integrally on the side of the transition structure away from the substrate 100, so that the second insulating layer 400 can form a first protrusion 421 and a first recess 411 conformally according to the shape of the transition structure.

[0158] The ultrasonic transducer substrate provided in this application embodiment can simultaneously generate a first protrusion 421 and a first recess 411 in the second insulating layer 400 according to the third recess 430. This can further improve the uniformity of the thickness of the second insulating layer 400, making the first protrusion 421 correspond one-to-one with the first recess 411, forming a structure similar to a spring. This improves the supporting effect of the first protrusion 421 on the first recess 411, increases the surface area of ​​the second insulating layer 400, thereby improving the elasticity and ductility of the second insulating layer 400, expanding the linear relationship range between the magnitude of the force on the second insulating layer 400 and the magnitude of the deformation, improving the detection range and accuracy of the ultrasonic transducer for ultrasonic waves, further reducing the risk of breakage of the second insulating layer 400, extending the service life of the ultrasonic transducer substrate, and improving the reliability of the ultrasonic transducer.

[0159] In some feasible embodiments, the ratio of the size of the recess 410 in the thickness direction H of the second insulating layer 400 to the thickness of the second insulating layer 400 ranges from 4 / 5 to 1 / 5.

[0160] It should be noted that if the ratio of the dimension of the recess 410 in the thickness direction H of the second insulating layer 400 to the thickness of the second insulating layer 400 is too large, the connection between the edge of the recess 410 and the flat surface of the second insulating layer 400 will be prone to breakage. If the ratio is too small, the force acting on the surface of the second insulating layer 400 will have a smaller component along the recess 410, resulting in a weaker effect on reducing the force on the second insulating layer 400, making the second insulating layer 400 prone to breakage, and the linear relationship between the magnitude of the force on the second insulating layer 400 and the magnitude of the deformation is poor.

[0161] In some feasible embodiments, the ratio of the dimension of the third recess 430 in the thickness direction H of the first insulating layer 300 to the thickness of the first insulating layer 300 ranges from 4 / 5 to 1 / 5.

[0162] The ultrasonic transducer substrate provided in this application embodiment can generate a first protrusion 421 and / or a first recess 411 corresponding to the position of the third recess 430 by conforming the third recess 430. This makes the ratio of the size of the first protrusion 421 and / or the first recess 411 in the thickness direction H to the thickness of the second insulating layer 400 within the range of 4 / 5 to 1 / 5. This can further reduce the manufacturing difficulty of the first protrusion 421 and / or the first recess 411, avoid the size of the first protrusion 421 and / or the first recess 411 in the thickness direction H being too large or too small, and further reduce the risk of breakage of the second insulating layer 400, extend the service life of the ultrasonic transducer substrate, and improve the linear relationship between the magnitude of the force on the second insulating layer 400 and the magnitude of the deformation.

[0163] In some feasible implementations, the substrate 100 includes glass.

[0164] For example, the glass material can be alkali-free glass, alkali-containing glass, and tempered glass.

[0165] The ultrasonic transducer substrate provided in this application embodiment has a glass substrate that can improve light transmittance, so as to meet the transparency requirements of optical sensors in photoacoustic imaging integrated systems, enabling light to be transmitted clearly and improving the accuracy of the device.

[0166] In some feasible implementations, multiple vibration units are used, with each cavity 403 corresponding to a vibration unit.

[0167] For example, Figure 14 This is a schematic structural diagram of an ultrasonic transducer substrate provided in an embodiment of this application. Figure 14 As shown, the ultrasonic transducer substrate includes: a substrate 100, a first electrode 200, a first insulating layer 300, a second insulating layer 400, a second electrode 500, and an isolation structure 600. A cavity 403 is formed between the first insulating layer 300 and the second insulating layer 400. Adjacent cavities 403 are separated by the isolation structure 600 to form independent vibration units. Multiple vibration units share a second electrode 500.

[0168] It should be noted that by isolating the cavity 403 through the isolation structure 600 to form multiple vibration units, and by using a second electrode 500 to generate electrostatic force to control the vibration of the second insulating layer 400, or to generate an electrical signal based on the vibration amplitude of the second insulating layer 400, the unit area of ​​each vibration unit can be reduced. Furthermore, by using the isolation structure 600 to support the second insulating layer 400, the risk of breakage of the second insulating layer 400 can be reduced, the service life of the ultrasonic transducer substrate can be extended, and the reliability of the ultrasonic transducer can be improved.

[0169] In some feasible implementations, the cavity 403 corresponds one-to-one with the second electrode 500.

[0170] For example, Figure 15 This is a schematic structural diagram of another ultrasonic transducer substrate provided in an embodiment of this application. Figure 15 As shown, the ultrasonic transducer substrate includes: a substrate 100, a first electrode 200, a first insulating layer 300, a second insulating layer 400, a second electrode 500, and an isolation structure 600. A cavity 403 is formed between the first insulating layer 300 and the second insulating layer 400. Adjacent cavities 403 are separated by the isolation structure 600 to form independent vibration units. Different vibration units correspond to different second electrodes 500.

[0171] It should be noted that by isolating the cavity 403 through the isolation structure 600 to form multiple vibration units, and by using different second electrodes 500 to generate electrostatic force to control the vibration of different vibration units, or to generate electrical signals according to the vibration amplitude of the second insulating layer 400 in different vibration units, it is convenient to generate different ultrasonic waves in different directions, which can be used to sense ultrasonic waves from different directions, thereby improving the sound generation and detection effects of the ultrasonic transducer substrate.

[0172] In some feasible implementations, the orthographic projection of the cavity 403 onto the substrate 100 includes at least one of a circle and an ellipse.

[0173] It should be noted that the orthographic projection of cavity 403 onto substrate 100 can be used to determine the area where the ultrasonic transducer substrate can vibrate. When the orthographic projection of cavity 403 onto substrate 100 is circular, the ultrasonic transducer substrate can generate uniform ultrasonic signals in all directions and uniformly receive ultrasonic signals from all directions, thereby improving the sound emission and detection effects of the ultrasonic transducer substrate. When the orthographic projection of cavity 403 onto substrate 100 is elliptical, the tensile strength of the second insulating layer 400 can be enhanced along the minor axis of the ellipse, reducing the risk of breakage of the second insulating layer 400, expanding the emission range of the ultrasonic transducer, extending the service life of the ultrasonic transducer substrate, and improving the reliability of the ultrasonic transducer.

[0174] In some feasible embodiments, the ultrasonic transducer substrate further includes an encapsulation structure. The second insulating layer 400 has a via penetrating through it; the encapsulation structure is disposed within the via, and includes a connecting end and an encapsulation end. The connecting end is connected to the side of the first insulating layer 300 away from the substrate 100, and the encapsulation end covers the end of the via away from the substrate 100; the orthographic projection of the via on the substrate 100 falls within the orthographic projection of the encapsulation end on the substrate 100.

[0175] For example, Figure 16 This is a schematic structural diagram of another ultrasonic transducer substrate provided in an embodiment of this application. (See diagram below.) Figure 16 As shown, the ultrasonic transducer substrate includes: a substrate 100, a first electrode 200, a first insulating layer 300, a second insulating layer 400, a second electrode 500, and an encapsulation structure 700. A cavity 403 is formed between the first insulating layer 300 and the second insulating layer 400. The second insulating layer 400 is provided with a through hole that penetrates the second insulating layer 400. The encapsulation structure 700 is disposed in the through hole and is used to support the second insulating layer 400.

[0176] It should be noted that when cavity 403 is in contact with the external environment, the medium between the first electrode 200 and the second electrode 500 changes, thus affecting the capacitance between them. When a voltage is applied between the first electrode 200 and the second electrode 500, the resulting electrostatic force differs from the target electrostatic force, causing a difference between the vibration amplitude of the second insulating layer 400 and the target vibration amplitude, affecting the sound emission effect of the ultrasonic transducer substrate. When the second insulating layer 400 vibrates under external disturbance, the ultrasonic signal intensity determined by the capacitance between the first electrode 200 and the second electrode 500 differs from the actual intensity, affecting the detection accuracy of the ultrasonic transducer substrate.

[0177] The ultrasonic transducer substrate provided in this application embodiment, by providing a via in the second insulating layer 400 and having the encapsulation structure 700 pass through the via, can prevent gas exchange between the cavity 403 and the external environment, thus avoiding affecting the sound emission effect and detection accuracy of the ultrasonic transducer substrate.

[0178] For example, Figure 17 This is a schematic flowchart illustrating a method for fabricating an ultrasonic transducer substrate, as provided in an embodiment of this application. Figure 17 As shown, in a second aspect of this application, a method for fabricating an ultrasonic transducer substrate is provided, for fabricating an ultrasonic transducer substrate as described in any of the first aspects above. The fabrication method includes:

[0179] Step S110: A first electrode 200 is disposed on one side of the substrate 100.

[0180] For example, the first electrode 200 can be formed on one side of a glass substrate by magnetron sputtering, photolithography, or etching. The first electrode 200 can be a multilayer structure of one or more metals selected from aluminum, molybdenum, copper, gold, titanium, nickel, and silver.

[0181] Step S120: A first insulating layer 300 is provided on the side of the first electrode 200 away from the substrate 100.

[0182] For example, the first insulating layer 300 can be deposited and grown on the side of the first electrode 200 away from the substrate 100 by a PECVD (Plasma Enhanced Chemical Vapor Deposition) process.

[0183] Step S130: A sacrificial layer is provided on the side of the first insulating layer 300 away from the substrate 100.

[0184] For example, a sacrificial layer pattern can be prepared by magnetron sputtering, photolithography, or etching. The sacrificial layer can be a metal layer, such as a copper metal layer. The thickness of the sacrificial layer can range from 100 nm to 10 μm. The specific thickness parameters can be determined based on the emitted sound wave frequency in the ultrasonic transducer substrate's sound emission mode and the received sensitivity in the detection and reception mode.

[0185] Step S140: A second insulating layer 400 is provided on the side of the sacrificial layer away from the substrate 100, wherein the side of the second insulating layer 400 away from the substrate 100 has a recess 410 and / or a protrusion 420, and / or the side of the second insulating layer 400 close to the substrate 100 has a recess 410 and / or a protrusion 420.

[0186] For example, a second insulating layer 400 can be formed on the side of the sacrificial layer away from the substrate 100 using a PECVD process. The second insulating layer 400 may include silicon nitride and has a thickness ranging from 200 nm to 2 μm. The specific thickness parameters can be determined based on the emitted sound wave frequency in the ultrasonic transducer substrate's sound emission mode and the received sensitivity in the detection and reception mode. The surfaces of the second insulating layer 400 near the substrate 100 and away from the substrate 100 can be shaped using processes such as pressing and etching to obtain the recessed portion 410 and the protruding portion 420.

[0187] Step S150: A second electrode 500 is disposed on the side of the second insulating layer 400 away from the substrate 100.

[0188] For example, the second electrode 500 can be formed on the side of the second insulating layer 400 away from the substrate 100 by magnetron sputtering, photolithography, or etching. The second electrode 500 can be a multilayer structure of one or more metals selected from aluminum, molybdenum, copper, gold, titanium, nickel, and silver.

[0189] Step S160: Before or after setting the second electrode 500, remove the sacrificial layer so that a cavity 403 is formed between the side of the second insulating layer 400 close to the substrate 100 and the side of the first insulating layer 300 away from the substrate 100.

[0190] For example, the sacrificial layer can be removed using a wet etching process with an etching solution. The etching solution may include hydrogen peroxide, which avoids damage to other film layers. Furthermore, hydrogen peroxide has high fluidity and low viscosity, facilitating contact with the sacrificial layer through small vias, further minimizing damage to other film layers.

[0191] The method for preparing an ultrasonic transducer substrate provided in this application improves the flexibility of the second insulating layer 400 by providing a recess 410 and / or a protrusion 420 on one side of the second insulating layer 400. When the second insulating layer 400 vibrates under the action of electrostatic force and mechanical restoring force or under the action of ultrasonic waves, the force acting on the surface of the second insulating layer 400 can form a component along the inclined surface of the recess 410 and / or the protrusion 420, reducing the tensile force on the second insulating layer 400, reducing the risk of breakage of the second insulating layer 400, expanding the emission range of the ultrasonic transducer, extending the service life of the ultrasonic transducer substrate, improving the reliability of the ultrasonic transducer, and also expanding the linear relationship range between the magnitude of the force on the second insulating layer 400 and the magnitude of the deformation, thereby improving the detection range and accuracy of the ultrasonic transducer for ultrasonic waves.

[0192] In some feasible embodiments, when the second insulating layer 400 has a first protrusion 421 on the side near the substrate 100, before the second insulating layer 400 is provided on the side of the sacrificial layer away from the substrate 100, the method further includes: providing a fourth recess on the side of the sacrificial layer away from the substrate 100, wherein the shape of the surface of the first protrusion 421 near the substrate 100 matches the shape of the surface of the fourth recess away from the substrate 100.

[0193] For example, the side of the sacrificial layer away from the substrate 100 can be etched by an etching process to obtain the fourth recess. A second insulating layer 400 can be grown on the side of the sacrificial layer away from the substrate 100 by a process such as PECVD, so that a first protrusion 421 is formed on the surface of the second insulating layer 400 near the substrate 100, which matches the shape of the surface of the fourth recess away from the substrate 100.

[0194] The method for preparing the ultrasonic transducer substrate provided in this application embodiment can reduce the difficulty of forming the first protrusion 421 on the second insulating layer 400 by providing a fourth recess on the side of the sacrificial layer away from the substrate 100, thereby avoiding damage to the second insulating layer 400, further improving the strength of the second insulating layer 400, reducing the risk of breakage of the second insulating layer 400, extending the service life of the ultrasonic transducer substrate, and improving the reliability of the ultrasonic transducer device.

[0195] In some feasible embodiments, the second insulating layer 400 has a first recess 411 on the side away from the substrate 100 and a first protrusion 421 on the side of the second insulating layer 400 near the substrate 100, and the shape of the surface of the first recess 411 away from the substrate 100 matches the shape of the surface of the first protrusion 421 near the substrate 100, and the shape of the surface of the first recess 411 away from the substrate 100 matches the shape of the surface of the fourth recess away from the substrate 100.

[0196] For example, the side of the sacrificial layer away from the substrate 100 can be etched by an etching process to obtain the fourth recess. A second insulating layer 400 of equal thickness can be grown on the side of the sacrificial layer away from the substrate 100 by a process such as PECVD, so that the surface of the second insulating layer 400 near the substrate 100 is conformally formed with a first protrusion 421 and a first recess 411 that match the shape of the surface of the fourth recess away from the substrate 100.

[0197] The method for preparing the ultrasonic transducer substrate provided in this application embodiment can reduce the difficulty of forming the first protrusion 421 and the first recess 411 on the second insulating layer 400 by providing a fourth recess on the side of the sacrificial layer away from the substrate 100, thereby avoiding damage to the second insulating layer 400, further improving the strength of the second insulating layer 400, reducing the risk of breakage of the second insulating layer 400, extending the service life of the ultrasonic transducer substrate, and improving the reliability of the ultrasonic transducer device.

[0198] In some feasible embodiments, when the second insulating layer 400 has a first protrusion 421 on the side near the substrate 100, before the sacrificial layer is provided on the side of the first insulating layer 300 away from the substrate 100, the method further includes: providing a third recess 430 on the side of the first insulating layer 300 away from the substrate 100, wherein the shape of the surface of the first protrusion 421 near the substrate 100 matches the shape of the surface of the third recess 430 away from the substrate 100.

[0199] For example, the side of the first insulating layer 300 away from the substrate 100 can be etched using processes such as photolithography to form a third recess 430 on the side of the first insulating layer 300 away from the substrate 100. A sacrificial layer is then prepared using magnetron sputtering, photolithography, or etching processes, so that the sacrificial layer can conformally form a fourth recess. Subsequently, a second insulating layer 400 of equal thickness can be grown on the side of the sacrificial layer away from the substrate 100 using processes such as PECVD, so that a first protrusion 421 matching the shape of the surface of the second insulating layer 400 on the side near the substrate 100 is formed.

[0200] The method for fabricating an ultrasonic transducer substrate provided in this application embodiment can reduce the fabrication difficulty of the first protrusion 421 on the second insulating layer 400 by providing a third recess 430 on the side of the first insulating layer 300 away from the substrate 100, thereby avoiding damage to the second insulating layer 400, further improving the strength of the second insulating layer 400, reducing the risk of breakage of the second insulating layer 400, extending the service life of the ultrasonic transducer substrate, and improving the reliability of the ultrasonic transducer device.

[0201] In some feasible embodiments, the second insulating layer 400 has a first recess 411 on the side away from the substrate 100 and a first protrusion 421 on the side of the second insulating layer 400 near the substrate 100, and the shape of the surface of the first recess 411 away from the substrate 100 matches the shape of the surface of the first protrusion 421 near the substrate 100, and the shape of the surface of the first recess 411 away from the substrate 100 matches the shape of the surface of the third recess 430 away from the substrate 100.

[0202] For example, the side of the first insulating layer 300 away from the substrate 100 can be etched using processes such as photolithography to form a third recess 430 on the side of the first insulating layer 300 away from the substrate 100. A sacrificial layer is further prepared using magnetron sputtering, photolithography, or etching processes, so that the sacrificial layer can conformally form a fourth recess. Then, a second insulating layer 400 of equal thickness can be grown on the side of the sacrificial layer away from the substrate 100 using processes such as PECVD, so that the surface of the second insulating layer 400 near the substrate 100 conformally forms a first protrusion 421 and a first recess 411 that match the shape of the surface of the fourth recess away from the substrate 100.

[0203] The method for fabricating an ultrasonic transducer substrate provided in this application embodiment can reduce the fabrication difficulty of the first protrusion 421 and the first recess 411 on the second insulating layer 400 by providing a third recess 430 on the side of the first insulating layer 300 away from the substrate 100, thereby avoiding damage to the second insulating layer 400, further improving the strength of the second insulating layer 400, reducing the risk of breakage of the second insulating layer 400, extending the service life of the ultrasonic transducer substrate, and improving the reliability of the ultrasonic transducer device.

[0204] For example, Figure 18 This is a schematic flowchart illustrating another method for fabricating an ultrasonic transducer substrate provided in an embodiment of this application. Figure 18 As shown, the preparation method includes:

[0205] Step S210: A first electrode 200 is disposed on one side of the substrate 100.

[0206] Step S2200: A first insulating layer 300 is provided on the side of the first electrode 200 away from the substrate 100.

[0207] Step S230: A photoresist layer 800 is formed on the side of the first insulating layer 300 away from the substrate 100.

[0208] Step S240: Expose and develop the photoresist layer 800 to form a third recess 430 on the side of the first insulating layer 300 away from the substrate 100.

[0209] Step S250: A sacrificial layer 900 is provided on the side of the first insulating layer 300 away from the substrate 100, so that a fourth recess 440 matching the third recess 430 is formed on the side of the sacrificial layer 900 away from the substrate 100, wherein the sacrificial layer 900 includes a copper metal layer.

[0210] Step S260: A second insulating layer 400 is provided on the side of the sacrificial layer 900 away from the substrate 100, such that a first protrusion 421 is formed on the side of the second insulating layer 400 close to the substrate 100, and a first recess 411 is formed on the side of the second insulating layer 400 away from the substrate 100. The first protrusion 421 matches the fourth recess 440, and the first recess 411 matches the first protrusion 421.

[0211] Step S270: A second electrode 500 is disposed on the side of the second insulating layer 400 away from the substrate 100.

[0212] Step S280: Etch the side of the second insulating layer 400 away from the substrate 100 to obtain a via 701 that penetrates the second insulating layer 400.

[0213] Step S290: Inject etching solution through via 701 to bring the etching solution into contact with the sacrificial layer 900, remove the sacrificial layer 900, and obtain the cavity 403 between the first insulating layer 200 and the second insulating layer 400.

[0214] Step S2100: The encapsulation structure 700 is inserted into the via 701. The encapsulation structure includes a connecting end and an encapsulation end. The connecting end is connected to the side of the first insulating layer 300 away from the substrate 100. The encapsulation end covers the side of the via 701 away from the substrate 100. The orthographic projection of the via 701 on the substrate 100 falls into the orthographic projection of the encapsulation end on the substrate 100.

[0215] For example, Figure 19 This is a schematic structural diagram of an ultrasonic transducer provided in an embodiment of this application. Figure 19 As shown, in a third aspect of the present application, an ultrasonic transducer is provided, comprising: an ultrasonic transducer substrate 1000 as described in any of the first aspects above.

[0216] The ultrasonic transducer provided in this application embodiment improves the flexibility of the second insulating layer 400 by providing a recess 410 and / or a protrusion 420 on one side of the second insulating layer 400. When the second insulating layer 400 vibrates under the action of electrostatic force and mechanical restoring force or under the action of ultrasonic waves, the force acting on the surface of the second insulating layer 400 can form a component along the inclined surface of the recess 410 and / or the protrusion 420, reducing the tensile force on the second insulating layer 400, reducing the risk of breakage of the second insulating layer 400, expanding the emission range of the ultrasonic transducer, extending the service life of the ultrasonic transducer substrate 1000, improving the reliability of the ultrasonic transducer, and also expanding the linear relationship range between the magnitude of the force on the second insulating layer 400 and the magnitude of the deformation, thereby improving the detection range and accuracy of the ultrasonic transducer for ultrasonic waves.

[0217] It should be noted that the descriptions of each embodiment in the above embodiments have different focuses. For parts that are not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0218] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

[0219] Although preferred embodiments have been described in this specification, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this specification.

[0220] Obviously, those skilled in the art can make various modifications and variations to this specification without departing from its spirit and scope. Therefore, if such modifications and variations fall within the scope of the claims and their equivalents, this specification is also intended to include such modifications and variations.

Claims

1. An ultrasonic transducer substrate, characterized by, The ultrasonic transducing substrate comprises: a substrate; a first electrode disposed on one side of the substrate; a first insulating layer disposed on a side of the first electrode away from the substrate; a second insulating layer disposed on a side of the first insulating layer away from the substrate, a cavity being formed between a side of the second insulating layer close to the substrate and a side of the first insulating layer away from the substrate; a second electrode disposed on a side of the second insulating layer away from the substrate; the second insulating layer is configured to convert ultrasonic energy by vibration deformation; the side of the second insulating layer away from the substrate has a recessed portion and / or a protruding portion, and / or the side of the second insulating layer close to the substrate has a recessed portion and / or a protruding portion.

2. The ultrasonic transducing substrate according to claim 1, wherein: the second insulating layer is configured to deform by vibration under the driving of the first electrode and the second electrode; and / or the second insulating layer is configured to deform by vibration under the action of a received external ultrasonic wave.

3. The ultrasonic transducing substrate according to claim 1, wherein: in the case that the side of the second insulating layer away from the substrate has a first recessed portion and the side of the second insulating layer close to the substrate has a first protruding portion, a projection of the first protruding portion on the substrate at least partially covers a projection of the first recessed portion on the substrate; and / or in the case that the side of the second insulating layer away from the substrate has a first recessed portion and the side of the second insulating layer close to the substrate has a second recessed portion, a projection of the first recessed portion on the substrate does not overlap with a projection of the second recessed portion on the substrate; and / or in the case that the side of the second insulating layer away from the substrate has a second protruding portion and the side of the second insulating layer close to the substrate has a first protruding portion, a projection of the first protruding portion on the substrate does not overlap with a projection of the second protruding portion on the substrate.

4. The ultrasonic transducing substrate according to claim 3, wherein: in the case that the projection of the first protruding portion on the substrate at least partially covers the projection of the first recessed portion on the substrate, the projection of the first protruding portion on the substrate entirely covers the projection of the first recessed portion on the substrate.

5. The ultrasonic transducing substrate according to claim 3, wherein: in the case that the side of the second insulating layer away from the substrate has the first recessed portion and the side of the second insulating layer close to the substrate has the first protruding portion, a shape of a surface of the first protruding portion close to the substrate matches a shape of a surface of the first recessed portion away from the substrate covered by the projection.

6. The ultrasonic transducing substrate according to claim 1, wherein: the second insulating layer comprises a first region and a second region, the second region surrounding the first region; the recessed portion is disposed in the second region; and / or the protruding portion is disposed in the second region; and / or the second electrode is disposed in the first region.

7. The ultrasonic transduction substrate according to any one of claims 1 to 6, wherein a shape of a projection of the recesses on the substrate comprises at least one of a ring shape, a polygonal shape, a circular shape, and a strip shape; and / or, a shape of a projection of the protrusions on the substrate comprises at least one of a ring shape, a polygonal shape, a circular shape, and a strip shape.

8. The ultrasonic transduction substrate according to claim 7, wherein in a case where the shape of the projection of the recesses on the substrate comprises a ring shape, and the number of the recesses is plural, the plural recesses are arranged in concentric rings; and / or, in a case where the shape of the projection of the recesses on the substrate comprises an arcuate strip shape, and the number of the recesses is plural, the plural recesses have the same center of curvature; and / or, in a case where the shape of the projection of the recesses on the substrate comprises a circular shape and a polygonal shape, and the number of the recesses is plural, the plural recesses are arranged in an array; and / or, in a case where the shape of the projection of the protrusions on the substrate comprises a ring shape, and the number of the protrusions is plural, the plural protrusions are arranged in concentric rings; and / or, in a case where the shape of the projection of the protrusions on the substrate comprises an arcuate strip shape, and the number of the protrusions is plural, the plural protrusions have the same center of curvature; and / or, in a case where the shape of the projection of the protrusions on the substrate comprises a circular shape and a polygonal shape, and the number of the protrusions is plural, the plural protrusions are arranged in an array.

9. The ultrasonic transduction substrate according to claim 1, wherein in a case where the second insulating layer has a first protrusion on a side closer to the substrate, the first insulating layer has a third recess on a side farther from the substrate, and a shape of a surface of the first protrusion closer to the substrate matches a shape of a surface of the third recess farther from the substrate.

10. The ultrasonic transduction substrate according to claim 9, wherein in a case where the second insulating layer has a first recess on a side farther from the substrate, and the second insulating layer has a first protrusion on a side closer to the substrate, a projection of the first protrusion on the substrate covers a projection of the first recess on the substrate, and a shape of a surface of the first recess farther from the substrate matches a shape of a surface of the third recess farther from the substrate.

11. The ultrasonic transduction substrate according to claim 9, wherein a ratio of a size of the recess in a thickness direction of the second insulating layer to a thickness of the second insulating layer is in a range of 4 / 5 to 1 / 5; and / or, a ratio of a size of the third recess in a thickness direction of the first insulating layer to a thickness of the first insulating layer is in a range of 4 / 5 to 1 / 5; and / or, the substrate comprises glass. including: a plurality of vibration units, the cavities corresponding one-to-one to the vibration units; and / or, ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 12. The ultrasonic transduction substrate of claim 1, wherein, ​ ​ The cavities correspond one-to-one to the second electrodes. 13.The ultrasonic transduction substrate of claim 1, wherein, A normal projection of the cavities on the substrate comprises at least one of a circle and an ellipse.

14. The ultrasonic transduction substrate of claim 1, wherein, Further comprising: a packaging structure; The second insulating layer is provided with a via hole penetrating through the second insulating layer; The packaging structure is arranged in the via hole, and the packaging structure comprises a connecting end and a packaging end, the connecting end is connected to the side of the first insulating layer away from the substrate, and the packaging end covers the end of the via hole away from the substrate; A normal projection of the via hole on the substrate falls within a normal projection of the packaging end on the substrate.

15. A method for fabricating an ultrasonic transducer substrate, characterized in that, A method for preparing the ultrasonic transduction substrate as claimed in any one of claims 1 to 14, the method comprising: arranging a first electrode on one side of a substrate; arranging a first insulating layer on the side of the first electrode away from the substrate; arranging a sacrificial layer on the side of the first insulating layer away from the substrate; arranging a second insulating layer on the side of the sacrificial layer away from the substrate, wherein the side of the second insulating layer away from the substrate has a recess and / or a protrusion, and / or the side of the second insulating layer close to the substrate has a recess and / or a protrusion; arranging a second electrode on the side of the second insulating layer away from the substrate; before or after arranging the second electrode, removing the sacrificial layer to form a cavity between the side of the second insulating layer close to the substrate and the side of the first insulating layer away from the substrate.

16. The method of claim 15, wherein In the case where the side of the second insulating layer close to the substrate has a first protrusion, before arranging the second insulating layer on the side of the sacrificial layer away from the substrate, the method further comprises: arranging a fourth recess on the side of the sacrificial layer away from the substrate, wherein the shape of the side surface of the first protrusion close to the substrate matches the shape of the side surface of the fourth recess away from the substrate. 17.The method of claim 16, wherein, in the case where the side of the second insulating layer away from the substrate has a first recess, and the side of the second insulating layer close to the substrate has a first protrusion, the shape of the side surface of the first recess away from the substrate matches the shape of the side surface of the fourth recess away from the substrate. 18.The method of claim 15, wherein, in the case where the side of the second insulating layer close to the substrate has a first protrusion, before arranging the sacrificial layer on the side of the first insulating layer away from the substrate, the method further comprises: arranging a third recess on the side of the first insulating layer away from the substrate, wherein the shape of the side surface of the first protrusion close to the substrate matches the shape of the side surface of the third recess away from the substrate.

19. The method of claim 18, wherein In a case where the second insulating layer has a first recessed portion on a side distal from the substrate and a first protruding portion on a side proximal to the substrate, a shape of a surface of the first recessed portion distal from the substrate matches a shape of a surface of the first protruding portion proximal to the substrate, and a shape of a surface of the third recessed portion distal from the substrate matches the shape of the surface of the first recessed portion distal from the substrate.

20. An ultrasonic transducer device, characterized by Comprising: The ultrasonic transduction substrate of any one of claims 1 to 14.

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