Microphone

Abstract

A microphone (100), comprising a support (130); a plurality of beam structures (120), one end of each beam structure (120) being disposed on the support member (130), the plurality of beam structures (120) vibrating in a first direction, at least part of the beam structures (120) being provided with piezoelectric conversion components (140), the piezoelectric conversion components (140) being used for generating electrical signals in response to the vibration of the plurality of beam structures (120); the shell (110) is used for containing the supporting piece (130) and the beam structure (120), a first cavity (111) and a second cavity (112) are formed in the first direction and located on the two sides of the beam structure (120), a first sound guiding hole (1111) and a second sound guiding hole (1121) are formed in the shell (110), the first sound guiding hole (1111) is acoustically coupled with the first cavity (111), the second sound guiding hole (1121) is acoustically coupled with the second cavity (112), and the first sound guiding hole (1111) and the second sound guiding hole (1121) are acoustically coupled with the beam structure (120). The plurality of beam structures (120) are distributed at intervals in a second direction perpendicular to the first direction, and gaps among the plurality of beam structures (120) allow air to circulate between the first cavity (111) and the second cavity (112).

Description

A microphone Technical Field

[0001] This specification relates to the field of acoustics, and in particular to a microphone. Background Art

[0002] With the continuous upgrading of consumer electronics, the demand for directional microphones is increasing. They have huge potential applications in scene recognition, sound source localization, noise reduction calls, hearing assistance, etc. Therefore, it is desirable to provide a directional microphone.

[0003] Summary of the Invention

[0004] One of the embodiments of the present specification provides a microphone, comprising: a support member; a plurality of beam structures, one end of each beam structure being arranged on the support member, the plurality of beam structures vibrating along a first direction, at least some of the beam structures being provided with a piezoelectric conversion component, the piezoelectric conversion component being used to generate an electrical signal in response to the vibration of the plurality of beam structures; and a shell for accommodating the support member and the beam structures, a first cavity and a second cavity being formed along the first direction and on both sides of the beam structure, a first sound guide hole and a second sound guide hole being provided on the shell, the first sound guide hole being acoustically coupled to the first cavity, and the second sound guide hole being acoustically coupled to the second cavity, the plurality of beam structures being spaced apart and distributed in a second direction perpendicular to the first direction, and the gaps between the plurality of beam structures allowing air to flow between the first cavity and the second cavity.

[0005] In some embodiments, a ratio of length to width of each beam structure in the plurality of beam structures is in the range of 10-2000.

[0006] In some embodiments, a ratio of length to thickness of each beam structure in the plurality of beam structures is in the range of 80-2000.

[0007] In some embodiments, a length of each beam structure in the plurality of beam structures is in a range of 1 μm to 2000 μm.

[0008] In some embodiments, a width of each beam structure in the plurality of beam structures is in the range of 1 μm-100 μm.

[0009] In some embodiments, the thickness of each beam structure in the plurality of beam structures is in the range of 0.1 μm-10 μm.

[0010] In some embodiments, a distance between two adjacent beam structures in the plurality of beam structures in the second direction is in a range of 10 μm-100 μm.

[0011] In some embodiments, each beam structure in the plurality of beam structures has the same length.

[0012] In some embodiments, at least two beam structures in the plurality of beam structures have different lengths.

[0013] In some embodiments, the plurality of beam structures are located on different side walls of the support member.

[0014] In some embodiments, the resonant frequency of at least some of the beam structures in the plurality of beam structures is less than 20 kHz.

[0015] In some embodiments, a ratio of a distance between the piezoelectric conversion component and connection locations between the plurality of beam structures and the support member to a length of the beam structure where the piezoelectric conversion component is located is less than 1 / 2.

[0016] In some embodiments, a ratio of a projected area of ​​the piezoelectric conversion element on the beam structure provided with the piezoelectric conversion element is in the range of 1 / 10-1.

[0017] In some embodiments, the plurality of beam structures include a stress-modulating layer.

[0018] In some embodiments, the material of the piezoelectric conversion component includes at least one of zinc oxide, aluminum nitride, lead zirconate titanate (PZT), and polyvinylidene fluoride (PVDF) flexible piezoelectric materials.

[0019] In some embodiments, the other ends of at least some of the beam structures in the plurality of beam structures are connected to a vibration sensing portion, and a hole array is formed on the vibration sensing portion.

[0020] In some embodiments, the pore size of each pore in the pore array is in the range of 5 μm to 50 μm.

[0021] In some embodiments, the spacing between two adjacent holes in the hole array is in the range of 0.1 μm to 50 μm.

[0022] In some embodiments, the plurality of beam structures include a plurality of groups of beam structures, the vibration sensing portion includes a plurality of vibration sensing portions, and each vibration sensing portion in the plurality of vibration sensing portions is connected to a group of beam structures in the plurality of groups of beam structures.

[0023] In some embodiments, different vibration sensing portions have different projection areas in the first direction.

[0024] In some embodiments, a ratio of the length of each beam structure to the length of the vibration sensing portion connected thereto is in a range of 0.5-10.

[0025] In some embodiments, a projection area of ​​each vibration sensing portion in the first direction is larger than a projection area of ​​the beam structure connected thereto in the first direction.

[0026] In some embodiments, at least some of the multiple beam structures are located on different side walls of the support member, and at least some of the beam structures located on different side walls of the support member are connected to the same vibration sensing portion. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] This specification will be further described in the form of exemplary embodiments, which will be described in detail with reference to the accompanying drawings. These embodiments are not limiting, and in these embodiments, like numbers represent like structures, wherein:

[0028] FIG1 is a schematic structural diagram of a microphone according to some embodiments of this specification;

[0029] FIG2 is a diagram illustrating responses of a microphone under different angles between the direction of the sound wave and the vibration direction of the beam structure according to some embodiments of this specification;

[0030] FIG3 is a schematic diagram of an exemplary beam structure according to some embodiments of the present specification;

[0031] FIG4 is an exemplary distribution diagram of multiple beam structures according to some embodiments of the present specification;

[0032] FIG5 is an exemplary distribution diagram of multiple beam structures according to some embodiments of the present specification;

[0033] FIG6 is an exemplary distribution diagram of multiple beam structures according to some embodiments of the present specification;

[0034] FIG7 is an exemplary distribution diagram of multiple beam structures according to some embodiments of the present specification;

[0035] FIG8 is an exemplary distribution diagram of multiple beam structures according to some embodiments of the present specification;

[0036] FIG9 is an exemplary distribution diagram of multiple beam structures according to some embodiments of the present specification;

[0037] FIG10 is an exemplary distribution diagram of multiple beam structures according to some embodiments of the present specification;

[0038] FIG11 is an exemplary distribution diagram of multiple beam structures according to some embodiments of the present specification;

[0039] FIG12 is an exemplary distribution diagram of multiple beam structures according to some embodiments of the present specification;

[0040] FIG13 is an exemplary distribution diagram of multiple beam structures according to some embodiments of the present specification;

[0041] FIG14 is an exemplary distribution diagram of multiple beam structures according to some embodiments of the present specification;

[0042] FIG15 is an exemplary distribution diagram of multiple beam structures according to some embodiments of the present specification;

[0043] FIG16 is an exemplary distribution diagram of multiple beam structures according to some embodiments of the present specification;

[0044] FIG17 is an exemplary distribution diagram of multiple beam structures according to some embodiments of the present specification;

[0045] FIG18A is an exemplary distribution diagram of a piezoelectric conversion component according to some embodiments of the present specification;

[0046] FIG18B is an exemplary distribution diagram of a piezoelectric conversion component according to some embodiments of the present specification;

[0047] FIG19 is a schematic structural diagram of a beam structure according to some embodiments of this specification;

[0048] FIG20 is a schematic diagram of a vibration sensing unit according to some embodiments of this specification;

[0049] FIG21 is a schematic diagram showing the connection between a vibration sensing unit and a beam structure according to some embodiments of this specification; and

[0050] FIG22 is a schematic diagram showing the connection between a vibration sensing portion and a beam structure according to some embodiments of this specification. DETAILED DESCRIPTION

[0051] To more clearly illustrate the technical solutions of the embodiments of this specification, the following briefly describes the drawings required for describing the embodiments. Obviously, the drawings described below are merely examples or embodiments of this specification. Those skilled in the art can apply this specification to other similar scenarios based on these drawings without inventive effort. Unless otherwise apparent from the context or otherwise noted, the same reference numerals in the figures represent the same structure or operation.

[0052] It should be understood that the terms "system," "device," "unit," and / or "module" used herein are a method for distinguishing different components, elements, parts, portions, or assemblies at different levels. However, if other terms can achieve the same purpose, the terms may be replaced by other expressions.

[0053] As used in this specification and claims, unless the context clearly indicates otherwise, the words "a," "an," "an," and / or "the" do not refer to the singular but also include the plural. Generally speaking, the terms "comprises" and "include" only indicate the inclusion of the steps and elements specifically identified, and these steps and elements do not constitute an exclusive list. A method or apparatus may also include other steps or elements.

[0054] Flowcharts are used throughout this specification to illustrate the operations performed by systems according to embodiments of this specification. It should be understood that preceding or following operations do not necessarily need to be performed in exact order. Instead, the steps may be processed in reverse order or simultaneously. Furthermore, other operations may be added to these processes, or one or more operations may be removed from these processes.

[0055] The embodiments of this specification describe a piezoelectric microphone. In some embodiments, the piezoelectric microphone includes a shell and a plurality of beam structures. The shell has an interior containing a cavity, and the beam structure is located in the cavity. The shell forms a first cavity and a second cavity along a first direction and on both sides of the beam structure. A first sound guide hole and a second sound guide hole are provided on the shell, the first sound guide hole is acoustically coupled to the first cavity, and the second sound guide hole is acoustically coupled to the second cavity. The plurality of beam structures are spaced apart in a second direction perpendicular to the first direction, and the gaps between the plurality of beam structures allow air to circulate between the first cavity and the second cavity. The beam structure can generate vibrations along a first direction in response to an external sound signal (i.e., a sound wave), and at least some of the plurality of beam structures are provided with a piezoelectric conversion component, which is used to generate an electrical signal in response to the vibrations of the plurality of beam structures. It should be understood that the "first direction" in this specification refers to the vibration direction of the beam structure, the "second direction" refers to the direction in which the multiple beam structures are arranged, and the "third direction" refers to the extension direction between the two fixed ends (or the fixed end and the free end) of the beam structure (when the beam structure is connected to the vibration sensing unit, the third direction refers to the extension direction of the beam structure toward the vibration sensing unit). The first direction, the second direction, and the third direction are perpendicular to each other. The first direction can also be called the thickness direction of the beam structure, the second direction can also be called the width direction of the beam structure, and the third direction can also be called the length direction of the beam structure.

[0056] Specifically, sound waves propagate through the air through the gaps between the multiple beam structures. Since the flow of air molecules can generate viscous force, the beam structure will vibrate up and down driven by the viscous force of the air molecules. In some embodiments, the piezoelectric conversion component includes a piezoelectric element. Due to the piezoelectric effect of the piezoelectric element, when the piezoelectric element receives the mechanical vibration of the beam structure and deforms accordingly, the piezoelectric element will generate an electrical signal accordingly, thereby realizing the conversion of sound waves into electrical signals. The directions of the flow of air molecules caused by sound waves incident from different directions are different, and the directions of the viscous forces generated by air molecules with different flow directions are different. The amplitudes (i.e., displacements) generated by the viscous forces in different directions of the beam structure are different. Accordingly, the piezoelectric conversion component (piezoelectric element) receives the mechanical vibration of the beam structure and the resulting deformations are different, resulting in the generated electrical signals having different strengths, thereby realizing the direction recognition of the piezoelectric microphone. For example, when the sound source is located in the first direction relative to the beam structure, the amplitude generated by the beam structure is large and the corresponding electrical signal is strong; when the sound source is located in the third direction relative to the beam structure, the amplitude of the beam structure is small, almost no vibration is generated, and the corresponding electrical signal is weak. The direction recognition of the piezoelectric microphone is realized according to the strength of the generated electrical signal.

[0057] In some embodiments, the piezoelectric microphone's recognition of the direction of sound waves can be used to locate the sound source. By leveraging the directivity of the piezoelectric microphone and determining the distance of the sound waves, the sound source can be located. In some embodiments, the piezoelectric microphone's recognition of the direction of sound waves can be used for acoustic scene classification (ASC) to help identify acoustic scenes. In some embodiments, the piezoelectric microphone's recognition of the direction of sound waves can also be used for noise reduction calls, hearing assistance, and adaptive sound settings for devices (such as mobile phones and headphones).

[0058] FIG1 is a schematic structural diagram of a microphone according to some embodiments of this specification.

[0059] As shown in FIG1 , the microphone 100 may include a housing 110, a beam structure 120, and a support member 130. The housing 110 has an internal housing cavity, in which the beam structure 120 and the support member 130 are disposed. The support member 130 is used to support the beam structure 120, with one end of the beam structure 120 disposed on the support member 130. A piezoelectric converter 140 is provided on the beam structure 120 for generating an electrical signal in response to the vibration of the beam structure 120. The beam structure 120 and the support member 130 divide the housing cavity into a first cavity 111 and a second cavity 112 located on opposite sides of the beam structure 120 in a first direction (see FIG1 ). The housing 110 on the side of the beam structure 120 facing away from the support member 130 forms the first cavity 111, and the housing 110 on the side of the beam structure 120 closer to the support member 130 forms the second cavity 112. The housing 110 is provided with a first sound guide hole 1111 and a second sound guide hole 1121. The first sound guide hole 1111 is in communication with the first cavity 111, and the first cavity 111 is in acoustic communication with the exterior of the microphone 100 via the first sound guide hole 1111. The second sound guide hole 1121 is in communication with the second cavity 112, and the second cavity 112 is in acoustic communication with the exterior of the microphone 100 via the second sound guide hole 1121. In some embodiments, sound waves from outside the microphone 100 can enter the second cavity 112 through the second sound guide hole 1121, pass through the support member 130 and the beam structure 120, and then pass through the first cavity 111, being output through the first sound guide hole 1111. During this process, the sound waves can cause the beam structure 120 to vibrate along a first direction, and the piezoelectric conversion component 140 converts the mechanical vibration of the beam structure 120 into an electrical signal. In some embodiments, sound waves outside the microphone 100 may enter the first cavity 111 through the first sound guide hole 1111 and then be output through the second sound guide hole 1121 .

[0060] The housing 110 is a three-dimensional structure having an accommodating cavity (i.e., a hollow portion). In some embodiments, the housing 110 can be a regular shape such as a cuboid, a sphere, a polygon, a prism, or any irregular shape. In some embodiments, the housing 110 can be made of metal (e.g., stainless steel, copper, etc.), plastic (e.g., polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), and acrylonitrile-butadiene-styrene copolymer (ABS)), composite materials (e.g., metal-based composite materials or non-metal-based composite materials), epoxy resin, phenolic resin, ceramic, polyimide, glass fiber (e.g., FR4-glass fiber), etc., or any combination thereof.

[0061] The support member 130 is a structure with an open opening. The beam structure 120 is located at the open opening of the support member 130. The end of the support member 130 facing away from the beam structure 120 is connected to the housing 110, thereby dividing the accommodating cavity into a first cavity 111 and a second cavity 112 located on opposite sides of the beam structure 120 and the support member 130. In some embodiments, the support member 130 may be a cylindrical structure with two through ends, with one end of the cylindrical structure connected to the housing 110 and the other end connected to the beam structure 120. In some embodiments, the support member 130 may be made of a semiconductor material. Semiconductor materials may include, but are not limited to, silicon dioxide, silicon nitride, gallium nitride, zinc oxide, silicon carbide, etc.

[0062] In some embodiments, the beam structure 120 can be physically connected to the support member 130. The "connection" described in this specification can be understood as the connection between different parts of the same structure, or after preparing different parts or structures separately, the independent parts or structures are fixedly connected by welding, riveting, clamping, bolting, adhesive bonding, etc., or during the preparation process, a first part or structure is deposited on a second part or structure by physical deposition (e.g., physical vapor deposition) or chemical deposition (e.g., chemical vapor deposition).

[0063] In some embodiments, to prevent the connection between support member 130 and beam structure 120 from affecting the vibration of beam structure 120, beam structure 120 may be elastically connected to support member 130. In some embodiments, one end of beam structure 120 is elastically connected to the open inner wall of support member 130. In some embodiments, one end of beam structure 120 is elastically connected to the end surface of support member 130 near beam structure 120.

[0064] The beam structure 120 is used to convert audio signals (sound waves) into mechanical vibrations. In some embodiments, the beam structure 120 extends along a third direction (see FIG1 ) perpendicular to the first direction, and the beam structure 120 can generate vibrations along the first direction. In some embodiments, the beam structure 120 can be a sheet-like, rod-like structure, etc. In some embodiments, the material of the beam structure 120 can be a material having the ability to transmit vibrations. For example, the material of the beam structure 120 can include silicone, foam, plastic, rubber, metal, etc., or any combination thereof. In some embodiments, the beam structure 120 can be a component with good elasticity (i.e., prone to elastic deformation). For example, the beam structure 120 can include a spring (e.g., an air spring, a mechanical spring, an electromagnetic spring, etc.), a vibration transmitting piece, a shrapnel, a substrate, etc., or any combination thereof.

[0065] In some embodiments, the beam structure 120 can be a cantilever beam with one end fixed (for example, see FIG. 3 ). In some embodiments, the beam structure 120 can be a beam with both ends fixed (for example, see FIG. 6 ). In some embodiments, the microphone 100 includes multiple beam structures 120, with the multiple beam structures 120 spaced apart in a second direction (see FIG. 4-11 ) perpendicular to the first and third directions. The gaps between the multiple beam structures 120 allow air to flow between the first cavity 111 and the second cavity 112. In some embodiments, the multiple beam structures 120 can be distributed in various ways. For example, the multiple beam structures 120 can be distributed in the manner shown in FIG. 4-17 or FIG. 20-22 . In some embodiments, the beam structure 120 includes only one beam structure 120. In some embodiments, one beam structure 120 can be a cantilever beam with one end fixed to a support member 130. In this case, a gap exists between the free end of the beam structure 120 and the support member 130 to allow air to flow between the first cavity 111 and the second cavity 112. In some embodiments, a beam structure 120 may be a beam fixed at both ends, with an array of holes on the beam to allow air to circulate between the first cavity 111 and the second cavity 112. For more information about the beam structure 120, please refer to other parts of this specification, such as Figures 3-22 and related descriptions.

[0066] In some embodiments, a piezoelectric transducer 140 is provided on the beam structure 120. The piezoelectric transducer 140 can receive the mechanical vibration of the beam structure 120 and generate an electrical signal. In some embodiments, when the microphone 100 includes multiple beam structures 120, at least some of the beam structures 120 are provided with piezoelectric transducers 140 to generate electrical signals in response to the vibration of the multiple beam structures 120. For example, a portion of the multiple beam structures 120 may be provided with a piezoelectric transducer 140 to generate electrical signals in response to the vibration of this portion of the beam structures 120. In another example, each of the multiple beam structures 120 may be provided with a piezoelectric transducer 140 to generate electrical signals in response to the vibration of each beam structure 120. In some embodiments, the piezoelectric transducer 140 includes a piezoelectric element. When the piezoelectric transducer 140 vibrates in response to the vibration of the beam structure 120, the piezoelectric element deforms, and due to the piezoelectric effect of the piezoelectric element, the piezoelectric element generates an electrical signal. In some embodiments, the piezoelectric element may be composed of a material having a piezoelectric effect. Exemplary piezoelectric materials may include piezoelectric ceramics, piezoelectric crystals, piezoelectric polymers (e.g., polyvinylidene fluoride), etc., or any combination thereof. In some embodiments, the piezoelectric element may be in any shape, such as a film, a sheet, a block, a column, etc., or any combination thereof. In some embodiments, the piezoelectric element may be in a thin sheet shape that is adapted to the shape of the beam structure 120. In some embodiments, the piezoelectric element may be directly attached to the beam structure 120 by gluing or deposition. In some embodiments, the piezoelectric element may be connected to the beam structure 120 by snapping, buckling, or the like. In some embodiments, the piezoelectric element may be attached to the beam structure 120 by physical deposition or chemical deposition.

[0067] In some embodiments, when one or more beam structures 120 do not completely cover the opening of the support member 130, sound waves propagate through the air through the gaps between the beam structure 120 and the adjacent beam structures 120 and / or the gaps between the beam structure 120 and the support member 130. The directions of the flow of air molecules caused by sound waves incident from different directions are different, and the directions of the viscous forces generated by air molecules in different flow directions are different. The amplitudes (i.e., displacements) generated by the beam structure 120 driven by the viscous forces in different directions are different, and the amplitudes generated by the piezoelectric conversion component 140 are different. Accordingly, the deformations generated by the piezoelectric element are different, resulting in different strengths of the generated electrical signals, thereby enabling the direction recognition of the microphone 100. When a sound wave is incident from a direction parallel to the vibration of beam structure 120 (e.g., the first direction), because the sound wave is a longitudinal wave, the vibration direction of the air molecules is consistent with the propagation direction of the sound wave. Therefore, when the sound wave is incident perpendicularly, the vibration direction of the air is perpendicular to beam structure 120, which can produce a large velocity difference between the air and beam structure 120. This velocity difference can be converted into a viscous force, driving beam structure 120 to produce greater vibration. When the sound wave is incident from a direction perpendicular to the vibration of beam structure 120 (e.g., the second direction or the third direction), the vibration of the air molecules in the direction perpendicular to beam structure 120 is smaller, and thus the vibration of beam structure 120 is smaller. Therefore, microphone 100 exhibits very excellent directionality. Figure 2 shows the response of microphone 100 at different angles between the sound wave direction and the vibration direction of beam structure 120, according to some embodiments of this specification. As shown in Figure 2, when the microphone 100 is acted upon by sound waves in directions that are at angles of 90° and 270° to the vibration direction of the beam structure 120 (i.e., the incident direction of the sound waves is perpendicular to the vibration direction of the beam structure 120), the electrical signal is the weakest, that is, the acoustic response is the worst; when the microphone 100 is acted upon by sound waves in directions that are at angles of 0° and 180° to the vibration direction of the beam structure 120 (i.e., the incident direction of the sound waves is parallel to the vibration direction of the beam structure 120), the electrical signal is the strongest, that is, the acoustic response is the best.

[0068] In some embodiments, since the microphone 100 is very sensitive to the direction of sound wave incidence, in order to prevent the positions of the first sound guide hole 1111 and the second sound guide hole 1121 from affecting the direction of sound wave incidence, the first sound guide hole 1111 and the second sound guide hole 1121 can be arranged opposite the beam structure 120.

[0069] It should be noted that the above description of the microphone 100 is merely exemplary and does not limit the present specification to the embodiment described. In some embodiments, the support member 130 may be a structure independent of the housing 110 .

[0070] Figure 3 is a schematic diagram of an exemplary beam structure according to some embodiments of this specification. As shown in Figure 3, the beam structure 120 is a cantilever beam, one end of the beam structure 120 is a fixed end 121, and the other end away from the fixed end 121 in the third direction is a free end 122.

[0071] Fixed end 121 refers to a location on beam structure 120 in operation where the vibration acceleration or acceleration level is less than a vibration acceleration threshold or acceleration level threshold, and the cross-sectional angle thereof is less than a rotation angle threshold. By way of example only, the vibration acceleration level of fixed end 121 may be less than 5 dB, 3 dB, 1 dB, 0.8 dB, 0.6 dB, 0.4 dB, 0.2 dB, or 0.05 dB, and the cross-sectional angle may be less than 3°, 2°, 1°, 0.5°, 0.2°, or 0.05°, among others. In some embodiments, fixed end 121 is connected to support member 130. Free end 122 refers to the end of beam structure 120 that is free to vibrate. In some embodiments, free end 122 may be suspended or unconstrained.

[0072] In some embodiments, in order to enable the beam structure 120 to vibrate in response to the air viscosity caused by sound waves, the material of the beam structure 120 may include one or more of polysilicon, silicon nitride, and silicon oxide. In some embodiments, the material of the beam structure 120 may be polysilicon.

[0073] With reference to Figure 1 , the "first direction" referred to in this specification is the vibration direction of the beam structure 120, and is also the thickness direction of the beam structure 120. The "second direction" referred to in this specification is the arrangement direction of the beam structure 120, and is also the width direction of the beam structure 120. The "third direction" referred to in this specification is a direction perpendicular to the plane formed by the first and second directions, and is also the length direction of the beam structure 120.

[0074] In some embodiments, in order to enable beam structure 120 to vibrate in response to the air viscosity caused by sound waves, it is necessary to design the relevant structural parameters of beam structure 120 so that the relevant structural parameters of beam structure 120 are within the range that can be driven by air viscosity. In some embodiments, the longer and smaller the width (or thickness) of beam structure 120, the higher its sensitivity to sound wave vibrations. Correspondingly, the lower the acoustic impedance, the lower the resonant frequency of microphone 100. Therefore, the length, width, thickness and other relevant structural parameters of beam structure 120 can be designed within a reasonable range to reduce the acoustic impedance of beam structure 120 and thus its corresponding resonant frequency. Here, the length of beam structure 120 is the dimension L of beam structure 120 along the third direction (see Figure 3), the width of beam structure 120 is the dimension W of beam structure 120 along the second direction (see Figure 4), and the thickness of beam structure 120 is the dimension D of beam structure 120 along the first direction (see Figure 3).

[0075] In some embodiments, to improve the sensitivity of the beam structure 120, reduce the acoustic impedance, and lower the resonant frequency, the ratio of the length to the width of the beam structure 120 may be in the range of 1-2000. Preferably, the ratio of the length to the width of the beam structure 120 may be in the range of 10-2000. Preferably, the ratio of the length to the width of the beam structure 120 may be in the range of 100-2000. More preferably, the ratio of the length to the width of the beam structure 120 may be in the range of 200-2000.

[0076] In some embodiments, to improve the sensitivity of the beam structure 120, reduce acoustic impedance, and lower the resonant frequency, the ratio of the length to the thickness of the beam structure 120 may be in the range of 1-2000. Preferably, the ratio of the length to the thickness of the beam structure 120 may be in the range of 10-2000. Preferably, the ratio of the length to the thickness of the beam structure 120 may be in the range of 80-2000. Preferably, the ratio of the length to the thickness of the beam structure 120 may be in the range of 100-2000. More preferably, the ratio of the length to the thickness of the beam structure 120 may be in the range of 200-2000.

[0077] In some embodiments, to ensure that the dimensions of the beam structure 120 meet the requirements of lightweight and miniaturization of the microphone 100, and to improve the sensitivity of the beam structure 120, reduce acoustic impedance, and lower the resonant frequency, the length L of the beam structure 120 can be in the range of 1 μm to 2000 μm. Preferably, the length L of the beam structure 120 can be in the range of 10 μm to 2000 μm. More preferably, the length L of the beam structure 120 can be in the range of 100 μm to 2000 μm.

[0078] In some embodiments, to improve the sensitivity of the beam structure 120, reduce the acoustic impedance, and lower the resonant frequency, the width W of the beam structure 120 may be in the range of 1 μm to 100 μm. Preferably, the width W of the beam structure 120 may be in the range of 5 μm to 80 μm. More preferably, the width W of the beam structure 120 may be in the range of 10 μm to 50 μm.

[0079] In some embodiments, to improve the sensitivity of the beam structure 120, reduce the acoustic impedance, and lower the resonant frequency, the thickness D of the beam structure 120 may be in the range of 0.1 μm to 10 μm. Preferably, the thickness D of the beam structure 120 may be in the range of 0.1 μm to 8 μm. More preferably, the thickness D of the beam structure 120 may be in the range of 0.2 μm to 5 μm.

[0080] In some embodiments, based on the length-to-width ratio and the length-to-thickness ratio of each beam structure, the thickness of each beam structure can be determined first, and then the length and width of each beam structure can be determined based on the thickness of each beam structure. It should be understood that the above description of the length, width, thickness, and other structural parameters of the beam structure 120 applies not only to each beam structure 120 when the microphone 100 includes multiple beam structures 120, but also to the beam structure 120 when the microphone 100 includes only one beam structure 120.

[0081] In some embodiments, the microphone 100 includes multiple beam structures 120, which are spaced apart along the second direction. The smaller the spacing G (see FIG. 4 ) between adjacent beam structures 120 in the second direction, the denser the arrangement of the beam structures 120 in the second direction, the larger the contact area with sound waves passing through, and thus the greater the drive received by the air viscosity force, and the more sensitive the beam structures 120 are in response to the drive of the air viscosity force. However, the spacing between adjacent beam structures 120 cannot be too small. Excessively small spacing between adjacent beam structures 120 prevents air from flowing freely between the beam structures 120, resulting in a sound pressure difference between the first cavity 111 and the second cavity 112. Therefore, in some embodiments, to ensure that the multiple beam structures 120 can vibrate under the action of air viscosity, the spacing G between adjacent beam structures 120 in the second direction can be in the range of 10 μm to 100 μm. Preferably, the spacing G between adjacent beam structures 120 in the second direction can be in the range of 20 μm to 80 μm. More preferably, the interval G between adjacent beam structures 120 in the second direction may be in the range of 30 μm-60 μm.

[0082] Because the length, width, and / or thickness of the beam structure 120 affect the resonant frequency, when the microphone 100 includes multiple beam structures 120, in order to improve the sensitivity in a certain frequency band, the length-to-width ratio of each beam structure 120 in the multiple beam structures 120 may be equal. The length-to-width ratio of each beam structure 120 may be determined based on the frequency band for which the sensitivity needs to be improved. In some embodiments, in order to achieve higher sensitivity in multiple frequency bands, the length-to-width ratio of each beam structure 120 in the multiple beam structures 120 may not be completely equal or completely unequal. For example, the length-to-width ratio of some beam structures 120 may be equal, while the length-to-width ratio of another portion of the beam structures 120 may be unequal. For another example, the length-to-width ratio of each beam structure 120 may be unequal.

[0083] In order to improve the sensitivity in a certain frequency band, the ratio of the length to the thickness of each beam structure 120 in the multiple beam structures 120 may be equal. The ratio of the length to the thickness of each beam structure 120 may be determined according to the frequency band range for which the sensitivity needs to be improved. In some embodiments, in order to have higher sensitivity in multiple frequency bands, the ratio of the length to the thickness of each beam structure 120 in the multiple beam structures 120 may not be completely equal or completely unequal. For example, the ratio of the length to the thickness of some beam structures 120 may be equal, and the ratio of the length to the thickness of another part of the beam structures 120 may be unequal. For another example, the ratio of the length to the thickness of each beam structure 120 may be unequal.

[0084] Figure 4 is a schematic diagram of a beam structure according to some embodiments of the present application. Figure 5 is a schematic diagram of a beam structure according to some embodiments of the present application. Figure 6 is a schematic diagram of a beam structure according to some embodiments of the present application. Figure 7 is a schematic diagram of a beam structure according to some embodiments of the present application. Figure 8 is a schematic diagram of a beam structure according to some embodiments of the present application. Figure 9 is a schematic diagram of a beam structure according to some embodiments of the present application. Figure 10 is a schematic diagram of a beam structure according to some embodiments of the present application. Figure 11 is a schematic diagram of a beam structure according to some embodiments of the present application.

[0085] In order to improve the sensitivity of a certain frequency band, the length L of each beam structure 120 in the multiple beam structures 120 can be equal (as shown in Figures 4 to 7). The length L of each beam structure 120 can be determined according to the frequency band range for which the sensitivity needs to be improved. In some embodiments, in order to have higher sensitivity in multiple frequency bands, the length L of each beam structure 120 in the multiple beam structures 120 may not be completely equal or completely unequal. For example, the length L of some beam structures 120 may be equal, and the length L of another part of the beam structures 120 may be unequal. For another example, as shown in Figures 8 to 10, the length L of each beam structure 120 may be unequal.

[0086] In order to improve the sensitivity of a certain frequency band, the width W of each beam structure 120 in the multiple beam structures 120 can be equal (as shown in Figures 4 to 10). The width W of each beam structure 120 can be determined according to the frequency band range in which the sensitivity needs to be improved. In some embodiments, in order to have higher sensitivity in multiple frequency bands, the width W of each beam structure 120 in the multiple beam structures 120 may not be completely equal or completely unequal. For example, the width W of some beam structures 120 may be equal, and the width W of another part of the beam structures 120 may be unequal. For another example, as shown in Figure 11, the width W of each beam structure 120 may be unequal.

[0087] To improve sensitivity within a certain frequency band, the thickness D of each beam structure 120 in the multiple beam structures 120 can be equal. The thickness D of each beam structure 120 can be determined based on the frequency band for which sensitivity improvement is desired. In some embodiments, to achieve higher sensitivity across multiple frequency bands, the thickness D of each beam structure 120 in the multiple beam structures 120 can be unequal or non-equal. For example, the thickness D of some beam structures 120 can be equal, while the thickness D of other beam structures 120 can be non-equal. For another example, the thickness D of each beam structure 120 can be non-equal.

[0088] In order to make the multiple beam structures 120 produce a more uniform vibration amplitude driven by air molecules, the spacing G between each pair of adjacent beam structures 120 in the multiple beam structures 120 in the second direction can be equal (as shown in Figures 4 to 10). In some embodiments, in order to increase the vibration amplitude of some beam structures 120 in the multiple beam structures 120 (or reduce the vibration amplitude of the remaining beam structures), the spacing G between each pair of adjacent beam structures 120 may not be completely equal or completely unequal. For example, the spacing G between some adjacent beam structures 120 may be equal, and the spacing G between another part of adjacent beam structures 120 may be unequal. For another example, as shown in Figure 11, the spacing G between each pair of adjacent beam structures 120 may be unequal.

[0089] In some embodiments, since the primary frequency range of human voice is below 20 kHz (e.g., within the range of 20 Hz-20 kHz), to enable the microphone 100 to meet this frequency range, the resonant frequency of at least some of the beam structures 120 in the plurality of beam structures 120 is less than 20 kHz. In some embodiments, to ensure that the beam structures 120 have a good vibration response in the primary frequency range of human voice, the resonant frequency range of at least some of the beam structures 120 in the plurality of beam structures 120 may be less than 10 kHz. Preferably, the resonant frequency range of at least some of the beam structures 120 in the plurality of beam structures 120 may be less than 5 kHz. Preferably, the resonant frequency range of at least some of the beam structures 120 in the plurality of beam structures 120 may be less than 4 kHz. Preferably, the resonant frequency range of at least some of the beam structures 120 in the plurality of beam structures 120 may be less than 3.2 kHz. More preferably, the resonant frequency range of at least some of the beam structures 120 in the plurality of beam structures 120 may be less than 2.8 kHz.

[0090] In some embodiments, the ratio of length to width, the ratio of length to thickness, the length, width and / or thickness of the beam structure 120 affect the resonant frequency. Therefore, when the ratio of length to width, the ratio of length to thickness, the length, width and / or thickness of the beam structure 120 is different, the corresponding resonant frequency is also different. For example, when the ratio of the length to the width of the beam structure 120 is larger (for example, when the ratio of the length to the width of the beam structure 120 is in the range of 1000-2000), the ratio of the length to the thickness of the beam structure 120 is larger (for example, when the ratio of the length to the thickness of the beam structure 120 is in the range of 1000-2000), the length of the beam structure 120 is larger (for example, when the length of the beam structure 120 is in the range of 1000μm-2000μm), the width of the beam structure 120 is smaller (for example, when the width of the beam structure 120 is in the range of 1μm-50μm), and / or the thickness of the beam structure 120 is smaller (for example, when the thickness of the beam structure 120 is in the range of 1μm-5μm), the corresponding resonant frequency is lower (for example, the resonant frequency is less than 2k Hz); accordingly, when the ratio of the length to the width of the beam structure 120 is smaller (for example, when the ratio of the length to the width of the beam structure 120 is in the range of 1-1000), the ratio of the length to the thickness of the beam structure 120 is smaller (for example, when the ratio of the length to the thickness of the beam structure 120 is in the range of 0-1000), the length of the beam structure 120 is smaller (for example, when the length of the beam structure 120 is in the range of 1μm-1000μm), the width of the beam structure 120 is larger (for example, when the width of the beam structure 120 is in the range of 50μm-100μm), and / or the thickness of the beam structure 120 is larger (for example, when the thickness of the beam structure 120 is in the range of 5μm-10μm), the corresponding resonant frequency is higher (for example, the resonant frequency is in the range of 2kHz-4kHz). For another example, when the ratio of the length to the width of the beam structure 120 is larger (for example, when the ratio of the length to the width of the beam structure 120 is in the range of 1000-2000) and the ratio of the length to the thickness of the beam structure 120 is larger (for example, when the ratio of the length to the thickness of the beam structure 120 is in the range of 1000-2000), the corresponding resonant frequency is lower (for example, the resonant frequency is less than 2kHz); accordingly, when the ratio of the length to the width of the beam structure 120 is smaller (for example, when the ratio of the length to the width of the beam structure 120 is in the range of 1-1000) and the ratio of the length to the thickness of the beam structure 120 is smaller (for example, when the ratio of the length to the thickness of the beam structure 120 is in the range of 0-1000), the corresponding resonant frequency is higher (for example, the resonant frequency is in the range of 2kHz-4kHz).For another example, when the length of the beam structure 120 is constant, the smaller the width of the beam structure 120 (for example, when the width of the beam structure 120 is in the range of 1μm-50μm) and the smaller the thickness of the beam structure 120 (for example, when the thickness of the beam structure 120 is in the range of 1μm-5μm), the corresponding resonant frequency is lower (for example, the resonant frequency is less than 2kHz); accordingly, the larger the width of the beam structure 120 (for example, when the width of the beam structure 120 is in the range of 50μm-100μm) and the larger the thickness of the beam structure 120 (for example, when the thickness of the beam structure 120 is in the range of 5μm-10μm), the corresponding resonant frequency is higher (for example, the resonant frequency is in the range of 2kHz-4kHz). For another example, when the width of the beam structure 120 is constant, the longer the length of the beam structure 120 is (for example, when the length of the beam structure 120 is in the range of 1000μm-2000μm) and the smaller the thickness of the beam structure 120 is (for example, when the thickness of the beam structure 120 is in the range of 1μm-5μm), the corresponding resonant frequency is lower (for example, the resonant frequency is less than 2kHz); accordingly, the smaller the length of the beam structure 120 is (for example, when the length of the beam structure 120 is in the range of 1μm-1000μm) and the larger the thickness of the beam structure 120 is (for example, when the thickness of the beam structure 120 is in the range of 5μm-10μm), the corresponding resonant frequency is higher (for example, the resonant frequency is in the range of 2kHz-4kHz).

[0091] In some embodiments, as shown in FIG4 , a plurality of beam structures 120 are spaced apart in the second direction, and a spacing G exists between two adjacent beam structures 120. The beam structure 120 is a cantilever beam, a fixed end of which is connected to a side wall of the support member 130, and a free end thereof extends toward the opposite side wall of the support member 130. The plurality of beam structures 120 fixed on opposite sides of the support member 130 along the third direction are staggered. In some embodiments, as shown in FIG5 , a plurality of beam structures 120 are spaced apart in the second direction. The beam structure 120 is a cantilever beam, and the fixed ends of the plurality of cantilever beams are connected to the same side wall of the support member 130. In some embodiments, as shown in FIG6 , a plurality of beam structures 120 are spaced apart in the second direction, and the two ends of each beam structure 120 are respectively fixed to two opposite side walls of the support member 130 along the third direction. In some embodiments, as shown in FIG7 , a plurality of beam structures 120 are spaced apart in the second direction. Among them, some beam structures 120 are cantilever beams fixed at one end (also referred to as multiple first beam structures 120), and another part of the beam structures 120 are fixed at both ends (also referred to as multiple second beam structures 120). The fixed end of each first beam structure 120 is fixed to a side wall of the support member 130, and the two ends of each second beam structure 120 are respectively fixed to two opposite side walls of the support member 130 along the third direction. The multiple first beam structures 120 and the multiple second beam structures are spaced apart along the second direction. For example, one of the two adjacent beam structures 120 is a first beam structure 120 (i.e., a cantilever beam fixed at one end), whose fixed end is connected to a side wall of the support member 130, and whose free end extends toward the opposite side wall of the support member 130, and the other of the two adjacent beam structures 120 is a second beam structure 120 (i.e., a beam structure fixed at both ends), and the two ends of the second beam structure 120 along the third direction are respectively connected to the opposite side walls of the support member 130.

[0092] In some embodiments, as shown in FIG8 , the distribution of the plurality of beam structures 120 shown in FIG8 is similar to that shown in FIG4 , except that the lengths L of the plurality of beam structures 120 distributed on one side of the support member 130 along the third direction are equal, while the lengths L of the plurality of beam structures 120 distributed on the other side of the support member 130 along the third direction are unequal (for example, as shown in FIG8 , the lengths L of the plurality of beam structures 120 distributed on the other side of the support member 130 along the third direction increase along the second direction). In some embodiments, as shown in FIG9 , the distribution of the plurality of beam structures 120 shown in FIG9 is similar to that shown in FIG8 , except that the lengths L of the plurality of beam structures 120 distributed on the other side of the support member 130 along the third direction first increase and then decrease along the second direction. In some embodiments, as shown in FIG10 , the distribution of the plurality of beam structures 120 shown in FIG10 is similar to that shown in FIG5 , except that the lengths L of the plurality of beam structures 120 distributed on one side of the support member 130 are different (for example, decreasing along the second direction). The beam structures 120 shown in FIG8-10 have different lengths L, and their resonant frequencies are different, and the frequencies of the sound waves responding to vibration are different. By designing beam structures 120 with different lengths L, the microphone 100 can have better sensitivity to sound frequencies in different frequency bands.

[0093] In some embodiments, as shown in FIG11 , the distribution of the multiple beam structures 120 shown in FIG11 is similar to that shown in FIG5 or FIG10 , except that at least some of the beam structures 120 have different widths W, and at least some of the spacings G between adjacent beam structures 120 are different. Beam structures 120 with different widths W have different resonant frequencies and respond to different frequencies of sound waves. By designing beam structures 120 with different widths W, the microphone 100 can better sense sound frequencies in different frequency bands. Beam structures 120 with different spacings G between adjacent beam structures can have significantly different vibration amplitudes. By designing beam structures 120 with different spacings G between adjacent beam structures, the vibration amplitudes of some beam structures 120 can be increased (or the vibration amplitudes of other beam structures can be reduced).

[0094] Different distribution modes of the multiple beam structures 120 can also be shown in Figures 12 to 17. In some embodiments, as shown in Figure 12, the multiple beam structures 120 are spaced apart in the second direction. The beam structure 120 is a cantilever beam fixed at one end, and the fixed end of a portion of the beam structure 120 (also referred to as the third beam structure 120) is connected to one side wall of the support member 130, and the fixed end of another portion of the beam structure 120 (also referred to as the fourth beam structure 120) is connected to the other side wall of the support member 130 along the third direction. The free end of the third beam structure 120 is arranged relative to the free end of the fourth beam structure 120 in a one-to-one correspondence. The "one-to-one correspondence" here means that each third beam structure 120 has a fourth beam structure 120 arranged opposite it, and the two one-to-one corresponding beam structures are aligned along the center line of the second direction. In some embodiments, as shown in FIG12 , the lengths L of the plurality of beam structures 120 (also referred to as third beam structures 120) distributed along one side of the support member 130 along the third direction decrease along the second direction, while the lengths L of the plurality of beam structures 120 (also referred to as fourth beam structures 120) distributed along the other side of the support member 130 along the third direction increase along the second direction. In some embodiments, the lengths L of the longest and shortest beam structures 120 among the plurality of beam structures 120 distributed along one side are respectively the same as the lengths L of the longest and shortest beam structures 120 among the plurality of beam structures 120 distributed along the other side.

[0095] In some embodiments, as shown in FIG13 , a plurality of beam structures 120 are disposed on two perpendicular sides of a support member 130. The beam structures 120 are cantilever beams fixed at one end. The beam structures 120 fixed to one of the two perpendicular sides of the support member 130 are spaced apart in the third direction, while the beam structures 120 fixed to the other side are spaced apart in the second direction. In some embodiments, the lengths L of the beam structures 120 on one side decrease along the second direction, while the lengths L of the beam structures 120 on the other side decrease along the third direction. In some embodiments, the lengths L of the longest and shortest beam structures 120 on one side are the same as the lengths L of the longest and shortest beam structures 120 on the other side. In some embodiments, as shown in FIG14 , the beam structures 120 are disposed on one side of the support member 130 extending in the third direction, with the beam structures 120 spaced apart in the third direction. The beam structures 120 are cantilever beams fixed at one end. The lengths L of the multiple beam structures 120 distributed on one side of the support member 130 extending along the third direction may be the same or different (for example, as shown in FIG14 , the lengths L of the multiple beam structures 120 distributed on one side of the support member 130 extending along the third direction decreases along the third direction).

[0096] In some embodiments, as shown in FIG15 , the plurality of beam structures 120 may be spaced apart in the third direction, and the lengths L of the plurality of beam structures 120 may be different (e.g., the lengths L of the plurality of beam structures 120 may decrease along the third direction). For example, the lengths L of the beam structures 120 may decrease exponentially in the third direction. In some embodiments, as shown in FIG16 , the plurality of beam structures 120 may be spaced apart in the third direction, and the lengths L of the plurality of beam structures 120 may increase and then decrease along the third direction. Specifically, the plurality of beam structures 120 may be symmetrically distributed about the centerline of the support member 130 in the third direction. In some embodiments, as shown in FIG17 , the plurality of beam structures 120 may be spaced apart in the third direction, and the lengths L of the plurality of beam structures 120 may decrease and then increase along the third direction. Specifically, the plurality of beam structures 120 may be symmetrically distributed about the centerline of the support member 130 in the third direction.

[0097] It should be understood that the distribution of the multiple beam structures 120 shown in Figures 4-17 is for exemplary purposes only, and the embodiments of the multiple beam structures 120 are not limited thereto. In one or more embodiments, the multiple beam structures 120 can be arranged in various planar or three-dimensional forms at the openings of the support member 130. In addition, one or more of the length, width, and / or thickness of each beam structure 120, as well as the spacing between adjacent beam structures 120, can be varied.

[0098] FIG18A is an exemplary distribution diagram of piezoelectric converter components according to some embodiments of this specification. As shown in FIG18A , the beam structure 120 and the support member 130 are connected at a connection 131. The connection 131 is located on the sidewall of the support member 130 along the third direction. The stress near the connection 131 between the beam structure 120 and the support member 130 is greatest. Since the piezoelectric output is proportional to the stress, in some embodiments, as shown in FIG18A , to achieve a higher piezoelectric output from the piezoelectric converter component 140, the piezoelectric converter component 140 may be located near the connection 131 between the beam structure 120 and the support member 130. In some embodiments, to achieve a higher piezoelectric output from the piezoelectric converter component 140, the distance between the piezoelectric converter component 140 and the connection 131 is within a range of 0 μm to 100 μm. Here, the distance between the piezoelectric converter component 140 and the connection 131 refers to the distance between the side of the piezoelectric converter component 140 closest to the connection 131 and the connection 131 in the third direction. In some embodiments, the distance between the piezoelectric converter component 140 and the connection portion 131 is within a range of 0 μm to 50 μm. In some embodiments, to achieve a higher piezoelectric output from the piezoelectric converter component 140, the distance between the piezoelectric converter component 140 and the connection portion 131 is 0 μm, i.e., the side of the piezoelectric converter component 140 closest to the connection portion 131 overlaps with the connection portion 131 in the third direction. In some embodiments, to achieve a higher piezoelectric output from the piezoelectric converter component 140, the ratio of the distance between the piezoelectric converter component 140 and the connection portion 131 to the length of the beam structure 120 in which the piezoelectric converter component 140 is located is less than 1 / 2. For example, the ratio of the distance between the piezoelectric converter component 140 and the connection portion 131 to the length of the beam structure 120 in which the piezoelectric converter component 140 is located is less than 1 / 3. For another example, the ratio of the distance between the piezoelectric converter component 140 and the connection portion 131 to the length of the beam structure 120 in which the piezoelectric converter component 140 is located is less than 1 / 4.

[0099] Figure 18B is an exemplary distribution diagram of piezoelectric conversion components according to some embodiments of the present specification. As shown in Figure 18B, the beam structure 120 is connected to the support member 130 at a connection portion 131. The connection portion 131 is located on the side wall of the support member 130 along the first direction.

[0100] In some embodiments, the piezoelectric area of ​​the piezoelectric converter 140 is related to the conversion efficiency of the piezoelectric converter 140 in converting mechanical vibrations into electrical signals. A smaller piezoelectric area indicates lower conversion efficiency. The piezoelectric area of ​​the piezoelectric converter 140 refers to the projected area of ​​the piezoelectric elements in the piezoelectric converter 140 along the first direction that sense the mechanical vibrations of the beam structure 120, deform, and generate electrical signals. The piezoelectric area is consistent with the projected area of ​​the piezoelectric converter 140 along the first direction. Therefore, in some embodiments, to ensure higher conversion efficiency and greater deformation, the piezoelectric converter 140 is positioned close to the connection portion 131, and the piezoelectric area of ​​the piezoelectric converter 140 should be larger. In some embodiments, the projected area ratio of the piezoelectric converter 140 on the beam structure 120 to which the piezoelectric converter 140 is mounted is within the range of 1 / 10-1. The projected area ratio refers to the ratio of the projected area of ​​the piezoelectric converter 140 along the first direction to the projected area of ​​the beam structure 120 along the first direction. At the same time, the portion of the beam structure 120 away from the connection portion 131 of the support member 130 experiences less deformation, resulting in a weaker electrical signal and lower efficiency in arranging the piezoelectric material. Therefore, to ensure both high conversion efficiency and greater deformation, the projected area ratio of the piezoelectric conversion component 140 on the beam structure 120 where the piezoelectric conversion component 140 is located is within a range of 1 / 10 to 2 / 3 (i.e., the piezoelectric conversion component 140 only covers a portion of the beam structure 120, not the entire beam structure 120). More preferably, to position the piezoelectric conversion component 140 closer to the connection portion 131, the projected area ratio is within a range of 1 / 3 to 1 / 2.

[0101] In some embodiments, the material of the piezoelectric conversion component 140 may include one or more piezoelectric materials such as zinc oxide (ZnO), tin oxide (SnO), lead zirconate titanate (PZT), zinc stannate (ZnSnO3), polyvinylidene fluoride (PVDF), poly(vinylidene fluoride-trifluoroethylene), aluminum nitride (AlN), and PMN-PT. In some embodiments, to reduce the acoustic impedance of the piezoelectric conversion component 140 and thereby reduce the resonant frequency of the beam structure 120, the material of the piezoelectric conversion component 140 may include one or more flexible piezoelectric materials such as lead zirconate titanate (PZT) and polyvinylidene fluoride (PVDF). In some embodiments, to further reduce the acoustic impedance of the beam structure 120 and reduce the resonant frequency of the beam structure 120, the material of the beam structure 120 may include one or more flexible piezoelectric materials such as lead zirconate titanate (PZT) and polyvinylidene fluoride (PVDF). In this case, the beam structure 120 and the piezoelectric conversion component 140 may be an integrated design.

[0102] In some embodiments, due to the large length of the beam structure 120, its internal stress is large, which may cause the beam structure 120 to warp after processing release. In order to adjust the shape of the beam structure 120 after processing release, the beam structure 120 may include a stress regulation layer 123. The direction of the internal stress of the stress regulation layer 123 is opposite to the direction of the internal stress of the beam structure 120, which can straighten the warped beam structure 120. Figure 19 is a schematic structural diagram of a beam structure according to some embodiments of this specification. In some embodiments, as shown in Figure 19, the stress regulation layer 123 is adapted to the shape of the beam structure 120. The stress regulation layer 123 can be connected (e.g., attached) to the lower side of the beam structure 120 near the second cavity 112. In other embodiments, the stress regulation layer 123 can also be connected (e.g., attached) to the upper side of the beam structure 120 near the first cavity 111. In some embodiments, the stress regulation layer 123 can also be connected (e.g., attached) to the upper side of the beam structure 120 near the first cavity 111 and the lower side near the second cavity 112. In some embodiments, the material of the stress regulating layer includes one or more semiconductor sputtering materials such as silicon nitride and silicon oxide.

[0103] FIG. 20 is a schematic diagram of a vibration sensing unit according to some embodiments of the present specification.

[0104] In some embodiments, since the deformation of the end of the beam structure 120 away from the connection portion 131 connected to the support member 130 (e.g., the free end) is smaller, as shown in FIG20 , one end of the beam structure 120 is fixed to the support member 130, and the end of the beam structure 120 away from the connection portion 131 connected to the support member 130 is connected to the vibration sensing unit 150. The vibration sensing unit 150 can generate vibrations in response to sound waves, thereby driving the beam structure 120 to vibrate, while increasing the contact area between the beam structure 120 and the airflow caused by the sound waves, thereby achieving a larger vibration displacement of the beam structure 120. In some embodiments, the vibration sensing unit 150 can be in the form of a sheet, a membrane, a block, a column, or the like. In some embodiments, in order to increase the vibration displacement of the vibration sensing unit 150 and thereby achieve a larger vibration displacement of the beam structure 120, a hole array 151 can be provided on the vibration sensing unit 150. The hole array 151 includes a plurality of micropores distributed in an array. In order to conform to the flow direction of air molecules, the openings of the micropores are opened along a first direction. Because the flow of air molecules generates viscous forces, the vibration sensor 150 vibrates up and down under the influence of these forces. The hole array 151 provided on the vibration sensor 150 reduces the resistance to sound waves passing through the vibration sensor 150, allowing the sound waves to pass through the vibration sensor 150 with minimal loss. At this point, the viscous forces of the air have a significant impact on the vibration sensor 150, driving it to vibrate with a large amplitude.

[0105] In some embodiments, in order to allow sound waves to pass through the vibration sensing portion 150 with less loss (that is, the vibration speed of the air molecules in each aperture is similar to the vibration speed of the outside world, and the viscosity of the air molecules has the greatest impact at this time), and at the same time, to allow the sound waves to have a sufficiently large contact area with the micropores on the vibration sensing portion 150, the pore size of the micropores on the vibration sensing portion 150 can be in the range of 5μm-50μm. For example, the pore size of the micropores on the vibration sensing portion 150 is in the range of 10μm-40μm. For another example, the pore size of the micropores on the vibration sensing portion 150 is in the range of 15μm-30μm. For another example, the pore size of the micropores on the vibration sensing portion 150 is in the range of 20μm-25μm. In some embodiments, in order to allow sound waves to pass through the vibration sensing portion 150 with less loss, the spacing between two adjacent holes in the hole array 151 is in the range of 0.1μm-50μm. For example, the spacing between two adjacent holes in the hole array 151 is in the range of 1μm-40μm. For another example, the spacing between two adjacent holes in the hole array 151 is in the range of 2 μm to 30 μm. For another example, the spacing between two adjacent holes in the hole array 151 is in the range of 5 μm to 20 μm.

[0106] In some embodiments, to enable the beam structure 120 to vibrate in response to air viscosity and to enable the vibration sensing unit 150 to drive the beam structure 120 to vibrate with a large amplitude, the ratio of the length of each beam structure 120 to the length of the vibration sensing unit 150 connected thereto in the third direction should be within an appropriate range. If the length of the beam structure 120 in the third direction is too large, the vibration sensing unit 150 will be too small and unable to effectively vibrate in response to air viscosity. If the length of the beam structure 120 in the third direction is too small, the resonant frequency of the vibration system formed by the beam structure 120 and the vibration sensing unit 150 will be too high and far away from the main frequency band of human voice. In some embodiments, the ratio of the length of the beam structure 120 to the vibration sensing unit 150 is within a range of 0.5-10. For example, the ratio of the length of the beam structure 120 to the vibration sensing unit 150 is within a range of 0.5-5. For another example, the ratio of the length of the beam structure 120 to the vibration sensing unit 150 is within a range of 0.5-2.

[0107] In some embodiments, in order to increase the viscosity of air molecules on the vibration sensing portion 150 so that the corresponding vibration amplitude generated by the beam structure 120 is larger, the area of ​​the vibration sensing portion 150 should be as large as possible. To this end, in some embodiments, the projection area of ​​the vibration sensing portion 150 in the first direction is larger than the projection area of ​​the beam structure 120 connected thereto in the first direction. The projection area of ​​the vibration sensing portion 150 in the first direction refers to the sum of the projection areas of all micropores in the hole array 151 on the vibration sensing portion 150 in the first direction and the projection areas of all non-hollow parts in the first direction. In some embodiments, when there are multiple beam structures 120 connected to one vibration sensing portion 150, the projection area of ​​the beam structure 120 connected to the vibration sensing portion 150 in the first direction refers to the sum of the projection areas of the multiple beam structures 120 connected thereto in the first direction.

[0108] In some embodiments, the microphone 100 includes multiple beam structures 120, at least some of which are connected to the first sidewall of the support member 130, while another portion of the beam structures 120 is connected to the second sidewall of the support member. The first sidewall and the second sidewall are different sidewalls of the support member 130. For example, the first sidewall and the second sidewall can be two sidewalls that are opposite each other along the third direction. For another example, the first sidewall and the second sidewall can be two sidewalls that are perpendicular to each other. Figure 21 is a schematic diagram of the connection between the vibration sensing portion and the beam structure according to some embodiments of this specification. As shown in Figure 21, some of the beam structures 120 are connected to the first sidewall 132 of the support member 130, and another portion of the beam structures 120 are connected to the second sidewall 133 of the support member. The first sidewall 132 and the second sidewall 133 are two sidewalls that are opposite each other along the third direction. In some embodiments, as shown in Figure 21, at least some of the beam structures 120 located on different sidewalls of the support member 130 are connected to the same vibration sensing portion 150.

[0109] In some embodiments, referring to FIG20 , multiple beam structures 120 are located on the same side wall of the support member 130 , one end of the beam structure 120 is connected to the side wall of the support member 130 , and the other ends of the multiple beam structures 120 are connected to the same vibration sensing portion 150 . In some embodiments, referring to FIG21 , multiple beam structures 120 are located on different side walls of the support member 130 , one end of the beam structure 120 is connected to the side wall of the support member 130 , and the other ends of the multiple beam structures 120 are connected to the same vibration sensing portion 150 . In some embodiments, the multiple beam structures 120 are distributed around the vibration sensing portion 150 . For example, the multiple beam structures 120 can be distributed on the inner wall of the cylindrical support member 130 , with one end of the multiple beams connected to the inner wall of the support member and the other end connected to the vibration sensing portion 150 , forming a distribution surrounding the vibration sensing portion 150 .

[0110] In some embodiments, multiple beam structures 120 may be connected to different vibration sensing units 150. For example, the multiple beam structures 120 may include multiple groups of beam structures 120, and the vibration sensing unit 150 may include multiple vibration sensing units 150. Each vibration sensing unit 150 in the multiple vibration sensing units 150 may be connected to a group of beam structures 120 in the multiple groups of beam structures 120. In some embodiments, the number of beam structures 120 included in each group of beam structures 120 may be the same or different.

[0111] Figure 22 is a schematic diagram illustrating the connection between the vibration sensing portion and the beam structure according to some embodiments of this specification. To ensure that the microphone 100 has high sensitivity across multiple audio bands, the resonant response for different frequency bands can be achieved by adjusting the projected area of ​​each vibration sensing portion 150 in the first direction and the length of the beam structures 120 included in each group of beam structures 120. In some embodiments, as shown in Figure 22, each group of beam structures 120 is connected to a corresponding vibration sensing portion 150 to form a microphone unit, and the multiple groups of beam structures 120 and the corresponding vibration sensing portions 150 each form multiple microphone units. In some embodiments, the lengths of each group of beam structures 120 vary. For example, the lengths of the multiple groups of beam structures 120 arranged along the second direction increase in magnitude. In some embodiments, the projected area of ​​the vibration sensing portion 150 corresponding to each group of beam structures 120 in the first direction varies. The projected area of ​​the vibration sensing portion 150 also affects the resonant frequency of the corresponding microphone unit. The different lengths of each group of beam structures 120 and / or the different projected areas of the corresponding vibration sensing portions 150 in the first direction can ensure that each microphone unit has a unique resonant frequency. For example, the resonance frequencies of the plurality of microphone units are f1, f2, ..., fn. The microphone 100 configured in this way can be adapted to receive sounds in different frequency bands and can also achieve sound directivity in different frequency bands.

[0112] It should be noted that the structural parameters (for example, the ratio of length to width, the ratio of length to thickness, length, width, thickness, the spacing between two adjacent beam structures 120, etc.), materials, distribution methods, and the piezoelectric conversion components 140 and stress regulation layers 123 arranged on the beam structure 120 shown in Figures 20-22 can be implemented with reference to other embodiments in this specification, for example, the embodiments shown in Figures 4-19.

[0113] The beneficial effects that may be brought about by the embodiments of this specification include but are not limited to: (1) by setting a beam structure and designing a piezoelectric conversion component on the beam structure, the beam structure generates different vibrations under sound signals in different directions, so that the piezoelectric microphone has directionality; (2) by designing the structural parameters of the beam structure (for example, the ratio of length to width, the ratio of length to thickness, the length, width, thickness, the distance between two adjacent beam structures 120, etc.) and the material, the beam structure can be made to vibrate in response to the air viscosity caused by sound waves, and the sensitivity of the beam structure in response to sound wave vibration is increased, thereby improving the sensitivity of the piezoelectric microphone; (3) by adaptively setting the length, width, thickness and the ratio of length to width and the ratio of length to thickness of the beam structure, the resonant frequency of the beam structure can be adjusted so that the microphone can meet a certain frequency; (4) by setting multiple groups of beam structures and vibration sensing parts and adjusting the size of each group of beam structures and vibration sensing parts accordingly, the microphone can have higher sensitivity in multiple frequency bands, can adapt to the sound reception of different sound frequency bands, and can also achieve sound directionality in different frequency bands.

[0114] While the basic concepts have been described above, it will be apparent to those skilled in the art that the detailed disclosure is merely illustrative and does not limit this specification. Although not explicitly stated herein, various modifications, improvements, and revisions to this specification may be made by those skilled in the art. Such modifications, improvements, and revisions are suggested in this specification and remain within the spirit and scope of the exemplary embodiments of this specification.

[0115] This specification also uses specific terms to describe the embodiments of this specification. For example, "one embodiment," "an embodiment," and / or "some embodiments" refer to a feature, structure, or characteristic associated with at least one embodiment of this specification. Therefore, it should be emphasized and noted that references to "one embodiment," "an embodiment," or "an alternative embodiment" two or more times in different locations in this specification do not necessarily refer to the same embodiment. Furthermore, certain features, structures, or characteristics of one or more embodiments of this specification may be appropriately combined.

[0116] In addition, unless expressly stated in the claims, the order of processing elements and sequences, the use of alphanumeric characters, or the use of other names in this specification are not intended to limit the order of the processes and methods of this specification. Although the above disclosure discusses some embodiments of the invention that are currently considered useful through various examples, it should be understood that such details are for illustrative purposes only, and the appended claims are not limited to the disclosed embodiments. On the contrary, the claims are intended to cover all modifications and equivalent combinations that are consistent with the spirit and scope of the embodiments of this specification. For example, although the system components described above can be implemented by hardware devices, they can also be implemented only by software solutions, such as installing the described system on an existing server or mobile device.

[0117] Similarly, it should be noted that, in order to simplify the presentation of this specification and thus facilitate understanding of one or more embodiments of the invention, the foregoing descriptions of the embodiments of this specification sometimes combine multiple features into a single embodiment, figure, or description thereof. However, this disclosure method does not imply that the subject matter of this specification requires more features than those recited in the claims. In fact, an embodiment may have fewer features than all of the features of a single disclosed embodiment.

[0118] In some embodiments, numbers are used to describe the quantity of components and attributes. It should be understood that such numbers used in the description of the embodiments are modified by the modifiers "about", "approximately" or "substantially" in some examples. Unless otherwise stated, "about", "approximately" or "substantially" indicate that the numbers are allowed to vary by ±20%. Accordingly, in some embodiments, the numerical parameters used in the description and claims are approximate values, which may change according to the required characteristics of individual embodiments. In some embodiments, the numerical parameters should take into account the specified significant digits and adopt the general method of retaining digits. Although the numerical domains and parameters used to confirm the breadth of their range in some embodiments of this specification are approximate values, in specific embodiments, the settings of such numerical values ​​are as accurate as possible within the feasible range.

[0119] Each patent, patent application, patent application publication, and other materials, such as articles, books, specifications, publications, and documents, cited in this specification is hereby incorporated by reference in its entirety. This includes application history documents that are inconsistent with or conflict with the content of this specification, as well as documents (currently or subsequently attached to this specification) that limit the broadest scope of the claims of this specification. It should be noted that if the descriptions, definitions, and / or terminology used in the accompanying materials are inconsistent with or conflict with the content of this specification, the descriptions, definitions, and / or terminology used in this specification will control.

[0120] Finally, it should be understood that the embodiments in this specification are intended only to illustrate the principles of the embodiments of this specification. Other variations may also fall within the scope of this specification. Therefore, by way of example and not limitation, alternative configurations of the embodiments of this specification may be considered consistent with the teachings of this specification. Accordingly, the embodiments of this specification are not limited to the embodiments explicitly described and illustrated in this specification.

Claims

1. A microphone, comprising: Supports; A plurality of beam structures, one end of each beam structure is disposed on a support member, the plurality of beam structures vibrate along a first direction, at least some of the beam structures are provided with a piezoelectric conversion component, the piezoelectric conversion component is used to generate an electrical signal in response to the vibration of the plurality of beam structures; as well as A shell is used to accommodate the support member and the beam structure, and a first cavity and a second cavity are formed along the first direction and on both sides of the beam structure. A first sound guide hole and a second sound guide hole are opened on the shell, the first sound guide hole is acoustically coupled with the first cavity, and the second sound guide hole is acoustically coupled with the second cavity. The multiple beam structures are spaced apart and distributed in a second direction perpendicular to the first direction, and the gaps between the multiple beam structures allow air to flow between the first cavity and the second cavity.

2. The microphone according to claim 1, characterized in that A ratio of the length to the width of each of the plurality of beam structures is in the range of 10-2000.

3. The microphone according to claim 1 or claim 2, characterized in that: A ratio of length to thickness of each of the plurality of beam structures is in the range of 80-2000.

4. The microphone according to claim 2 or claim 3, characterized in that: The length of each beam structure in the plurality of beam structures is in the range of 1 μm-2000 μm.

5. The microphone according to any one of claims 2 to 4, characterized in that: The width of each beam structure of the plurality of beam structures is in the range of 1 μm-100 μm.

6. The microphone according to any one of claims 2 to 5, characterized in that: The thickness of each of the plurality of beam structures is in the range of 0.1 μm to 10 μm.

7. The microphone according to any one of claims 1 to 6, characterized in that: The interval between two adjacent beam structures in the plurality of beam structures in the second direction is in the range of 10 μm-100 μm.

8. The microphone according to any one of claims 1 to 7, characterized in that: The length of each beam structure in the plurality of beam structures is the same.

9. The microphone according to any one of claims 1 to 7, characterized in that: At least two of the plurality of beam structures have different lengths.

10. The microphone according to any one of claims 1 to 9, characterized in that: The plurality of beam structures are located on different side walls of the support member.

11. The microphone according to any one of claims 1 to 10, characterized in that: The resonant frequency of at least some of the beam structures among the plurality of beam structures is less than 20 kHz.

12. The microphone according to any one of claims 1 to 11, characterized in that: The ratio of the distance between the piezoelectric conversion component and the connection parts between the plurality of beam structures and the support member to the length of the beam structure where the piezoelectric conversion component is located is less than 1 / 2.

13. The microphone according to any one of claims 1 to 12, characterized in that: A projected area ratio of the piezoelectric conversion element on the beam structure provided with the piezoelectric conversion element is in the range of 1 / 10-1.

14. The microphone according to any one of claims 1 to 13, characterized in that: The plurality of beam structures include a stress regulating layer.

15. The microphone according to any one of claims 1 to 14, characterized in that: The material of the piezoelectric conversion component includes at least one of zinc oxide, aluminum nitride, lead zirconate titanate (PZT), and polyvinylidene fluoride (PVDF) flexible piezoelectric materials.

16. The microphone according to any one of claims 1 to 15, characterized in that: The other end of at least part of the beam structures among the plurality of beam structures is connected to a vibration sensing part, and a hole array is formed on the vibration sensing part.

17. The microphone according to claim 16, characterized in that The pore size of each pore in the pore array is in the range of 5 μm-50 μm.

18. The microphone according to claim 16 or claim 17, characterized in that: The spacing between two adjacent holes in the hole array is in the range of 0.1 μm-50 μm.

19. The microphone according to claim 16, characterized in that The plurality of beam structures include a plurality of groups of beam structures, the vibration sensing portion includes a plurality of vibration sensing portions, and each of the plurality of vibration sensing portions is connected to a group of beam structures in the plurality of groups of beam structures.

20. The microphone according to claim 19, characterized in that The projection areas of different vibration sensing parts in the first direction are different.

21. The microphone according to claim 16, characterized in that The ratio of the length of each beam structure to the length of the vibration sensing part connected thereto is in the range of 0.5-10.

22. The microphone according to claim 16, characterized in that A projection area of ​​each vibration sensing portion in the first direction is larger than a projection area of ​​the beam structure connected thereto in the first direction.

23. The microphone according to claim 16, characterized in that At least some of the multiple beam structures are located on different side walls of the support member, and at least some of the beam structures located on different side walls of the support member are connected to the same vibration sensing part.

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