MEMS element and electro-acoustic conversion apparatus

Abstract

A MEMS element and an electro-acoustic conversion apparatus, relating to the technical field of microphones. The MEMS element comprises spacers, counter electrodes, a first diaphragm, and a second diaphragm. The spacers and the counter electrodes are located on the same horizontal plane and are alternately arranged in a cross section of the MEMS element; the first diaphragm and the second diaphragm are respectively disposed on opposite sides of the spacers and are in airtight connection with one another; the first diaphragm comprises a plurality of first protrusions disposed at intervals along a first direction, and the second diaphragm comprises a plurality of second protrusions disposed at intervals along the first direction, wherein the first protrusions and the second protrusions are in one-to-one correspondence and align with one another to form cavities, and the counter electrodes are suspended within the cavities; each first protrusion comprises a first front wall and a first rear wall, each second protrusion comprises a second front wall and a second rear wall, and at least part of the first front walls, the first rear walls, the second front walls, or the second rear walls are sub-corrugated structures. The MEMS element effectively reduces the maximum stress applied to the diaphragms under high-pressure impact, thus ultimately enhancing the mechanical robustness of the apparatus.

Description

A MEMS element and electroacoustic conversion device Technical Field

[0001] The present invention relates to the technical field of electroacoustic conversion devices, and in particular to a MEMS element and an electroacoustic conversion device. Background Art

[0002] In the field of micro-electro-mechanical system (MEMS) microphones, some structures may be designed with a sealed cavity surrounded by two corrugated diaphragms, where the sealed cavity presents a reduced air pressure and has a backplate that acts as a counter electrode to form a capacitive differential sensing system. Technical issues

[0003] When a dual-diaphragm structure is subjected to high pressure (from a drop or air impact—approximately 1 MPa), the diaphragm experiences correspondingly high upward or downward displacements (on the order of tens of microns). Such high displacements can cause high stress locally in the diaphragm and potentially create cracks in the material, compromising the structure and ultimately damaging the microphone.

[0004] It would therefore be desirable to provide an improved MEMS component that overcomes at least one of the above-mentioned problems. Technical Solutions

[0005] To solve the above technical problems, an embodiment of the present invention provides a MEMS element, comprising:

[0006] a plurality of spacers arranged along a first direction,

[0007] a plurality of pairs of electrodes arranged along a first direction,

[0008] a plurality of slots, each of which is formed between adjacent counter electrodes and spacers;

[0009] The first diaphragm includes a plurality of first protrusions spaced apart along a first direction;

[0010] The second diaphragm includes a plurality of second protrusions spaced apart along the first direction, and the second protrusions extend in a direction away from the first protrusions;

[0011] The plurality of spacers and the plurality of counter electrodes are located in the same horizontal plane and are alternately arranged on a cross section of the MEMS element;

[0012] The first diaphragm and the second diaphragm are respectively arranged on opposite sides of the spacer and are airtightly connected;

[0013] The plurality of first protrusions correspond to the plurality of second protrusions one-to-one, and the corresponding first protrusions and second protrusions are aligned with each other to form a cavity, and the counter electrode is suspended in the cavity;

[0014] The portion between two adjacent first protrusions is the first portion, the portion between two adjacent second protrusions is the second portion, the corresponding first portions and second portions are aligned, and the spacer is sandwiched between the first portion and the second portion;

[0015] The first protrusion includes a first front wall and a first rear wall disposed opposite to each other along a first direction, and the second protrusion includes a second front wall and a second rear wall disposed opposite to each other along the first direction;

[0016] At least a portion of the first front wall, the first rear wall, the second front wall, and the second rear wall is a sub-corrugated structure.

[0017] In some embodiments, the first front wall and the first rear wall adjacent to the first portion of the spacer connected to the edge of the first diaphragm are sub-corrugated structures, and the second front wall and the second rear wall adjacent to the second portion of the spacer connected to the edge of the second diaphragm are sub-corrugated structures.

[0018] In some embodiments, the first front wall and the first rear wall adjacent to the first portion of the spacer connected to the outermost circle or the sub-outer circle of the first diaphragm are sub-corrugated structures, and the second front wall and the second rear wall adjacent to the second portion of the spacer connected to the outermost circle or the sub-outer circle of the second diaphragm are sub-corrugated structures.

[0019] In some embodiments, the first front wall and the first rear wall adjacent to the first portion of the spacer connected to the outermost two or three turns of the first diaphragm are sub-corrugated structures, and the second front wall and the second rear wall adjacent to the second portion of the spacer connected to the outermost two or three turns of the second diaphragm are sub-corrugated structures.

[0020] In some embodiments, the first front wall and the first back wall adjacent to the first portion of all spacers connected to the first diaphragm are sub-corrugated structures, and the second front wall and the second back wall adjacent to the second portion of all spacers connected to the second diaphragm are sub-corrugated structures.

[0021] In some embodiments, the sub-corrugated structure includes a third peak and a third valley connected to each other along the first direction, the third peak is connected to the first portion and the second portion respectively, and the third valley is connected to the top of the first protrusion and the second protrusion respectively.

[0022] In some embodiments, the top of the third peak and the bottom of the third valley are conical or flat.

[0023] In some embodiments, the top of the third peak is lower than or flush with the tops of the first protrusion and the second protrusion.

[0024] In some embodiments, the bottom of the third valley is higher than or flush with the height of the first portion and the second portion.

[0025] In some embodiments, the length of the sub-corrugated structure in the first direction is smaller than the length of the first protrusion, the second protrusion, the first portion, or the second portion.

[0026] In some embodiments, the sub-corrugated structure is integrally formed with the first diaphragm or the second diaphragm.

[0027] In some embodiments, the shape and size of the first protrusion are the same as the shape and size of the second protrusion, and the length of the first portion is the same as the length of the second portion.

[0028] In some embodiments, the tops of the first protrusion and the second protrusion are flat, and the first portion and the second portion are flat.

[0029] In some embodiments, the cavity is sealed and the internal pressure is less than the external atmospheric pressure.

[0030] In some embodiments, the cavity is in a vacuum state.

[0031] In some embodiments, the first direction is radial or transverse.

[0032] In some embodiments, the first diaphragm and the second diaphragm are made of a conductive material, or include an insulating film with a conductive element provided on the film.

[0033] In some embodiments, the first diaphragm and the second diaphragm each further include a plurality of spokes, dividing the first diaphragm and the second diaphragm into a plurality of parts along a circumferential direction.

[0034] In some embodiments, at least a portion of the counter electrode is suspended between the sub-corrugated structure of the first diaphragm and the corresponding sub-corrugated structure of the second diaphragm, and the two opposite surfaces of the counter electrode are not in contact with the sub-corrugated structures of the first diaphragm and the second diaphragm respectively.

[0035] In order to solve the above technical problems, the present invention further provides an electroacoustic conversion device, comprising the MEMS element as described above, and a circuit electrically connected to the MEMS element. Beneficial effects

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] By configuring at least a portion of the first front wall, the first rear wall, the second front wall or the second rear wall to be a sub-corrugated structure, the sub-corrugated structure has an additional degree of freedom of bending, allowing it to have a different deformation from the dual-diaphragm structure and release stress through the deformation. Therefore, the stress at the corner where the first protrusion or the second protrusion is connected to the respective diaphragms can be shared, thereby ultimately reducing the maximum stress of the diaphragms; at the same time, the MEMS element can also maintain the original stiffness of the first diaphragm and the second diaphragm, thereby maintaining the original performance, thereby greatly improving the robustness of the device, effectively reducing the maximum stress applied to the diaphragm under high-pressure shock (drop, air shock), and ultimately improving the mechanical robustness of the device.

[0038] In addition, the micro-electromechanical system component of the present invention has high acoustic compliance and sensitivity.

[0039] The advantages of the electroacoustic converter over the prior art are the same as those of the aforementioned MEMS element, and will not be described in detail here. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] One or more embodiments are exemplarily illustrated by pictures in the corresponding drawings. These exemplifications do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are represented as similar elements. Unless otherwise stated, the figures in the drawings do not constitute proportional limitations.

[0041] FIG1 is a schematic top view of a MEMS element including radial corrugations in some embodiments of the present invention;

[0042] FIG2 is a partial cross-sectional view of the MEMS element in FIG1 according to an embodiment of the present invention;

[0043] FIG3 is a partial cross-sectional view of a MEMS element having sub-corrugations according to some embodiments of the present invention;

[0044] FIG. 4 is a partial cross-sectional view of a MEMS element having sub-corrugations according to other embodiments of the present invention.

[0045] The following are the explanations of the reference numerals: The reference numerals should not be construed as limiting the claims.

[0046] 11. Spacer; 12. Counter electrode; 13. Slot; 2. First diaphragm; 21. First protrusion; 22. First portion; 211. First front wall; 212. First rear wall; 4. Spoke rod; 3. Second diaphragm; 31. Second protrusion; 32. Second portion; 311. Second front wall; 312. Second rear wall; 41. Cavity; 5. Corrugated structure; 51. Third peak; 52. Third valley. Modes for Carrying Out the Invention

[0047] The present invention will be further described with reference to the accompanying drawings. It should be noted that elements with similar structures or functions are indicated by the same reference numerals throughout the figures. The embodiments described herein are not intended to be an exhaustive description or illustration of various other embodiments, nor are they intended to limit the scope of the claims or the scope of certain other embodiments that would be apparent to one of ordinary skill in the art based on the embodiments described herein. In addition, the illustrated embodiments do not necessarily have all the aspects or advantages shown. In the description of the present invention, it should be understood that the terms "first," "second," "third," etc. are primarily used to distinguish different devices, elements, or components (the specific types and configurations of which may be the same or different), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise specified, "plurality" means two or more.

[0048] The terms used in the various embodiments described herein are intended to describe specific embodiments only and are not intended to be limiting. As used in the description of the various embodiments described and the appended claims, the singular forms "a", "an", and "said" are also intended to include the plural forms, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any and all possible combinations of one or more of the relevant listed items. It should be further understood that the terms "comprises", "comprising", "having", and "having" when used in this specification specify the presence of the features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or combinations thereof.

[0049] 1 to 4 , an embodiment of the present invention provides a MEMS element. The MEMS element includes a plurality of spacers 11, a plurality of counter electrodes 12, a first diaphragm 2, and a second diaphragm 3. The plurality of spacers 11 and the plurality of counter electrodes 12 are arranged along a first direction, are located on the same horizontal plane, and are alternately arranged on the cross section of the MEMS element. A gap is left between adjacent counter electrodes 12 and spacers 11 to form a narrow groove 13. The first diaphragm 2 and the second diaphragm 3 have similar corrugated structures, each including a plurality of protrusions spaced apart along the first direction, and each protrusion extends in opposite directions in the second direction. In addition, the first diaphragm 2 and the second diaphragm 3 are arranged opposite to each other and are airtightly connected. In which, the first direction is expressed as radial or transverse, and the second direction is expressed as vertical.

[0050] For ease of description, the protrusions on the first diaphragm 2 are referred to as first protrusions 21, and the protrusions on the second diaphragm 3 are referred to as second protrusions 31. The first and second protrusions 21 and 31 can have the same shape and size. On surfaces perpendicular to the first and second diaphragms 2 and 3 (i.e., surfaces in the second direction), the shapes of the first and second protrusions 21 and 31 can be rectangular, trapezoidal, triangular, or the like.

[0051] The portion between two adjacent first protrusions 21 on the first diaphragm 2 is called the first portion 22 (i.e., the portion of the first diaphragm 2 excluding the first protrusions 21). The portion between two adjacent second protrusions 31 on the second diaphragm 3 is called the second portion 32 (i.e., the portion of the second diaphragm 3 excluding the second protrusions 31). The first portion 22 and the second portion 32 can have the same shape and size, for example, they can be flat. Therefore, the first portion 22 and the second portion 32 can have the same length.

[0052] The first protrusion 21 and the second protrusion 31 are aligned with each other to form a cavity 41, and the counter electrode 12 is suspended in the cavity 41. The first portion 22 is aligned with the second portion 32 and connected by the spacer 11. In other words, one end of the spacer 11 is connected to the first portion 22 and the other end is connected to the second portion 32, that is, the spacer 11 is sandwiched between the first portion 22 and the second portion 32.

[0053] The spacer 11 may be a pillar, etc. The spacer 11 may be formed integrally with the first diaphragm 2 or the second diaphragm 3. Alternatively, the spacer 11 may be formed between the first diaphragm 2 and the second diaphragm 3 after they are assembled together.

[0054] It should be noted that both the first diaphragm 2 and the second diaphragm 3 are corrugated conductive diaphragms of the same shape and size, typically circular. In some embodiments, the first diaphragm 2 and the second diaphragm 3 are divided into six sections along their circumference, with adjacent sections connected by spokes 4 extending in the radial direction (i.e., the first direction) of the diaphragms. In other words, the first and second diaphragms may further include multiple spokes 4. In other embodiments, the first diaphragm 2 and the second diaphragm 3 may also have other shapes, such as square, hexagonal, or octagonal, without limitation.

[0055] In some embodiments, the first corrugated conductive diaphragm 2 and the second corrugated conductive diaphragm 3 can be made of a conductive material or include an insulating film on which a conductive element is provided. For example, the first corrugated conductive diaphragm 2 and the second corrugated conductive diaphragm 3 include a silicon nitride film, wherein a polysilicon electrode is formed on the surface of the diaphragm facing the counter electrode 12 to provide electrical conductivity.

[0056] As shown in Figures 2 to 4, the first corrugated conductive diaphragm 2 includes a plurality of first protrusions 21 and a plurality of first portions arranged alternately along a first direction, while the second corrugated conductive diaphragm 3 includes a plurality of second protrusions 31 and a plurality of second portions arranged alternately along the first direction. The second protrusions 31 extend away from the first protrusions 21, while the second portions 32 extend toward the first portions 21. Because the first protrusions 21 and the second protrusions 31 have the same shape and size, and the first portions 22 and the second portions 32 also have the same shape and size, the first corrugated conductive diaphragm 2 and the second corrugated conductive diaphragm 3 have the same length.

[0057] It should be noted that the tops of the first protrusion 21 and the second protrusion 32 are, for example, but not limited to, flat, as shown in Figures 2 to 4. In other embodiments, the tops of the first protrusion 21 and the second protrusion 32 may also be V-shaped, arched, or arc-shaped, which is not limited here.

[0058] The protrusions of the first diaphragm 2 and the second diaphragm 3 respectively include front and rear walls arranged opposite to each other along the first direction. For ease of description, the front and rear walls of the first protrusion 21 may be referred to as the first front wall 211 and the first rear wall 212, and the front and rear walls of the second protrusion 31 may be referred to as the second front wall 311 and the second rear wall 312.

[0059] The inclination angles of the first front wall 211 , the first rear wall 212 , the second front wall 311 , and the second rear wall 312 may be greater than 0° but less than or equal to 90°.

[0060] Because high stresses may occur locally at the corners where the diaphragm connects to the front and rear walls when the diaphragm is subjected to high pressure, this can damage the structure. Therefore, in some embodiments, at least a portion of the front or rear wall is configured as a sub-corrugated structure 5. Specifically, as shown in Figures 3 and 4, at least a portion of the first front wall 211, the first rear wall 212, the second front wall 311, or the second rear wall 312 is configured as a sub-corrugated structure 5.

[0061] When the diaphragm is subjected to high pressure, the sub-corrugated structure 5 can effectively reduce the local stress through its own buffering, thereby effectively reducing the maximum stress applied to the diaphragm under high pressure shock (drop, air shock), and ultimately improving the mechanical robustness of the device.

[0062] Because when a MEMS element is subjected to high pressure (e.g., from a drop or air impact, up to 1 MPa), the inclined surfaces of the projections corresponding to the outermost and second-outermost spacers 11 are subject to the greatest local stress impact, preferably, the front and rear walls adjacent to the first and second portions of the spacers 11 connected to the outermost or second outermost rings of the first and second diaphragms are configured as sub-corrugated structures 5. In this case, the MEMS element can effectively reduce local stress while better maintaining its original characteristics.

[0063] In some embodiments, the front and rear walls adjacent to the first and second portions of the outermost two or three turns of the spacers 11 connected to the first and second diaphragms can be configured as sub-corrugated structures. In some embodiments, the front and rear walls adjacent to the first and second portions of all spacers connected to the first and second diaphragms can be configured as sub-corrugated structures.

[0064] As shown in Figures 3 and 4 , to maintain consistency in the radial or lateral extension of the diaphragm, in some embodiments, the sub-corrugated structures 5 are also arranged along the first direction. However, in other embodiments, the corrugated structures 5 may also be arranged at a certain angle (e.g., 0° to 30°) to the first direction, for example, along the original extension direction of the front wall or rear wall in Figure 2 , without limitation.

[0065] The sub-corrugated structure 5 includes third peaks 51 and third valleys 52 connected to each other along a first direction. The third peaks 51 extend away from the first and second diaphragms, respectively, while the third valleys 52 extend toward the first and second diaphragms, respectively. Specifically, the third peaks 51 connect to the first and second portions 22, 32, while the third valleys 52 connect to the tops of the first and second protrusions 21, 31. This connection refers to a third peak 51 connecting each end of the first and second portions 22, 32, and a third valley 52 connecting the tops of the first and second protrusions 21, 31, respectively.

[0066] The height of the third peak 51 is less than or equal to the height of the first protrusion 21 and the second protrusion 31. In some embodiments, the height of the third peak 51 is the same as the height of the first protrusion 21 and the second protrusion 31. The height described herein refers to the highest point.

[0067] The bottom of the third valley 52 is not lower than the height of the first portion 22 and the second portion 32. In some embodiments, the bottom of the third valley 52 is in the same plane as the first portion 22 and the second portion 32.

[0068] In some embodiments, the top of the third peak 51 and the bottom of the third valley 52 may be conical or flat.

[0069] In some embodiments, the length of the sub-corrugated structure 5 in the first direction is less than the length of the first protrusion 21, the second protrusion 31, the first portion 22, or the second portion 32. For example, including but not limited to, the length of the sub-corrugated structure 5 in the first direction may be 1 / 2, 1 / 3, 1 / 4, 2 / 3, 3 / 4, 2 / 5, 4 / 5, etc., of the length of the first protrusion 21, the second protrusion 31, the first portion 22, or the second portion 32.

[0070] In some embodiments, the sub-corrugated structure 5 may be integrally formed with the first diaphragm 2 and / or the second diaphragm 3 .

[0071] As shown in Figure 4, there is usually a gap between the sub-corrugated structure 5 at the first front wall 211 of the first protrusion 21 and the sub-corrugated structure 5 at the second front wall 311 of the second protrusion 31, and the electrode 12 can also be suspended in the gap, that is, at least a part of the electrode 12 is arranged between the sub-corrugated structure 5 of the first diaphragm 2 and the sub-corrugated structure 5 of the second diaphragm 3 opposite to it, and the two opposite surfaces of the electrode 12 are not in contact with the sub-corrugated structures 5 of the first diaphragm 2 and the second diaphragm 3.

[0072] The sub-corrugated structure 5 has an additional degree of bending freedom, allowing it to deform differently from the dual-diaphragm structure and release stress through this deformation. Consequently, the stress at the corner where the first or second protrusion 21 or 31 connects to the respective diaphragm is shared, ultimately reducing the maximum stress in the diaphragm. At the same time, the MEMS element maintains its original stiffness and performance.

[0073] Another embodiment of the present invention provides an electroacoustic transducer device, comprising the aforementioned MEMS element and a circuit electrically connected to the MEMS element. The electroacoustic transducer device may be a MMEMS microphone or a speaker.

[0074] Although the present invention has been described with reference to one or more embodiments, the above description of the embodiments is intended only to enable those skilled in the art to implement or use the present invention. It should be understood by those skilled in the art that various modifications may be made without departing from the spirit or scope of the present invention. The embodiments described above should not be construed as limiting the present invention, and the scope of the present invention should be determined with reference to the appended claims.

Claims

1. A micro-electromechanical system (MEMS) element, comprising: a plurality of spacers arranged along a first direction, A plurality of pairs of electrodes arranged along the first direction, a plurality of slots, each slot being formed between adjacent counter electrodes and spacers; A first diaphragm, comprising a plurality of first protrusions spaced apart along the first direction; A second diaphragm, comprising a plurality of second protrusions spaced apart along the first direction, wherein the second protrusions extend in a direction away from the first hollow protrusion; The plurality of spacers and the plurality of counter electrodes are located in the same horizontal plane and are alternately arranged in a cross section of the MEMS element; The first diaphragm and the second diaphragm are respectively arranged on opposite sides of the spacer and are airtightly connected; The plurality of first protrusions correspond to the plurality of second protrusions one by one, and the corresponding first protrusions and second protrusions are aligned with each other to form a cavity, and the pair of electrodes are suspended in the cavity; The portion between two adjacent first protrusions is the first portion, the portion between two adjacent second protrusions is the second portion, the corresponding first portions and second portions are aligned, and the spacer is sandwiched between the first portion and the second portion; The first protrusion includes a first front wall and a first rear wall disposed opposite to each other along the first direction, and the second protrusion includes a second front wall and a second rear wall disposed opposite to each other along the first direction; At least a portion of the first front wall, the first rear wall, the second front wall or the second rear wall is a sub-corrugated structure.

2. The MEMS element according to claim 1, wherein: The first front wall and the first rear wall adjacent to the first portion of the spacer connected to the edge of the first diaphragm are sub-corrugated structures, and the second front wall and the second rear wall adjacent to the second portion of the spacer connected to the edge of the second diaphragm are sub-corrugated structures.

3. The MEMS element according to claim 1, wherein: The first front wall and the first rear wall adjacent to the first part of the spacer connected to the outermost circle or the sub-outer circle of the first diaphragm are sub-corrugated structures, and the second front wall and the second rear wall adjacent to the second part of the spacer connected to the outermost circle or the sub-outer circle of the second diaphragm are sub-corrugated structures.

4. The MEMS element according to claim 1, wherein: The first front wall and the first rear wall adjacent to the first part of the spacer connected to the outermost two or three turns of the first diaphragm are sub-corrugated structures, and the second front wall and the second rear wall adjacent to the second part of the spacer connected to the outermost two or three turns of the second diaphragm are sub-corrugated structures.

5. The MEMS element according to claim 1, wherein: The first front wall and the first rear wall adjacent to the first portion of all spacers connected to the first diaphragm are sub-corrugated structures, and the second front wall and the second rear wall adjacent to the second portion of all spacers connected to the second diaphragm are sub-corrugated structures.

6. The MEMS element according to any one of claims 1 to 5, wherein: The sub-corrugated structure includes a third peak and a third valley connected to each other along the first direction, the third peak is connected to the first portion and the second portion, and the third valley is connected to the top of the first protrusion and the second protrusion.

7. The MEMS element according to claim 6, wherein: The top of the third peak and the bottom of the third valley are conical or flat.

8. The MEMS element according to claim 6 or 7, wherein: The top of the third peak is lower than or flush with the tops of the first protrusion and the second protrusion.

9. The MEMS element according to any one of claims 6 to 8, wherein: The bottom of the third valley is higher than or flush with the heights of the first portion and the second portion.

10. The MEMS element according to any one of claims 1 to 9, wherein: The length of the sub-corrugated structure in the first direction is smaller than the length of the first protrusion, the second protrusion, the first portion or the second portion.

11. The MEMS element according to claim 1, wherein: The sub-corrugated structure is integrally formed with the first diaphragm or the second diaphragm.

12. The MEMS element according to any one of claims 1 to 11, wherein: The shape and size of the first protrusion are the same as those of the second protrusion, and the length of the first portion is the same as that of the second portion.

13. The MEMS element according to any one of claims 1 to 12, wherein: The tops of the first protrusion and the second protrusion are flat, and the first portion and the second portion are flat.

14. The MEMS element according to any one of claims 1 to 13, wherein: The cavity is sealed, and the pressure inside the cavity is lower than the external atmospheric pressure.

15. The MEMS element according to any one of claims 1 to 14, wherein: The cavity is in a vacuum state.

16. The MEMS element according to any one of claims 1 to 15, wherein: The first direction is radial or transverse.

17. The MEMS element according to any one of claims 1 to 16, wherein: The first diaphragm and the second diaphragm are made of conductive material, or include a layer of insulating film, on which conductive elements are arranged.

18. The MEMS element according to any one of claims 1 to 17, wherein: The first diaphragm and the second diaphragm further each include a plurality of spokes, and the spokes divide the first diaphragm and the second diaphragm into a plurality of parts along a circumferential direction.

19. The MEMS element according to any one of claims 1 to 18, wherein: At least a portion of the counter electrode is suspended between the sub-corrugated structure of the first diaphragm and the corresponding sub-corrugated structure of the second diaphragm, and two opposite surfaces of the counter electrode are not in contact with the sub-corrugated structures of the first diaphragm and the second diaphragm respectively.

20. An electroacoustic conversion device, comprising the MEMS element according to any one of claims 1 to 19, and a circuit electrically connected to the MEMS element.

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