Diaphragm, MEMS chip, and sensor

Abstract

The present application discloses a diaphragm, a MEMS chip, and a sensor. The diaphragm comprises a diaphragm body and first annular fold portions; the diaphragm body comprises a first surface and a second surface; the first annular fold portions are arranged on the second surface, the first annular fold portions form first opening grooves passing through the first surface, and there are at least two first annular fold portions; the diaphragm body is provided with a central region, and the at least two first annular fold portions sequentially surround the central region along a first direction; and the shape dimensions of any two adjacent first annular fold portions are not completely the same, the shape dimensions comprise at least one of the thickness dimension of the first annular fold portions, the depth dimension and the width dimension of the first opening grooves, and the first direction is perpendicular to the vibration direction.

Description

Sensitive membranes, MEMS chips and sensors

[0001] Related applications

[0002] This application claims priority to Chinese patent application No. 202510141634.7, filed on February 8, 2025, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of acoustic-to-electric conversion equipment technology, and in particular to a sensitive membrane, a MEMS chip, and a sensor. Background Technology

[0004] MEMS microphones are packaged structures consisting of a metal casing and a printed circuit board (PCB). Inside the package, on the surface of the circuit board, is a MEMS microphone chip. Opposite the MEMS microphone chip, on the circuit board, is a sound hole for receiving sound signals. External sound passes through this sound hole to the MEMS microphone chip, achieving the sound intake effect. However, as the requirements for the mechanical sensitivity of MEMS microphone chips have gradually increased, existing MEMS microphones are finding it increasingly difficult to meet these demands. Summary of the Invention

[0005] The main objective of this application is to propose a sensitive membrane, a MEMS chip, and a sensor, aiming to solve the technical problem of how to improve the sensitivity of a MEMS microphone chip.

[0006] To achieve the above objectives, this application proposes a sensitive membrane comprising a membrane body and a first annular pleated portion. The membrane body includes a first surface and a second surface disposed opposite to each other along the vibration direction of the sensitive membrane. The first annular pleated portion is disposed on the second surface, and a first opening groove penetrating the first surface is formed inside the first annular pleated portion. The number of the first annular pleated portions is at least two. The membrane body has a central region, and at least two first annular pleated portions are sequentially arranged around the central region along a first direction. The shapes and dimensions of any two adjacent first annular pleated portions are not completely identical. The shapes and dimensions include at least one of the thickness of the first annular pleated portion, the depth of the first opening groove along the vibration direction, and the width of the first opening groove along the first direction. The first direction is perpendicular to the vibration direction.

[0007] In one embodiment, the thickness dimensions of any two adjacent first annular pleats are defined as a and b, respectively, then: b ≥ 101%a, or 0 < b ≤ 99%a; the depth dimension and the width dimension of the first opening groove of any two adjacent first annular pleats are the same;

[0008] or,

[0009] If the depth dimensions of the first opening groove of any two adjacent first annular pleats are defined as c and d respectively, then: d≥105%c, or 0<d≤95%c, and the thickness dimension and the width dimension of the first opening groove of any two adjacent first annular pleats are the same.

[0010] or,

[0011] If the width dimensions of the first opening groove of any two adjacent first annular pleats are defined as e and f respectively, then: f≥105%e, or 0<f≤95%e, and the thickness dimension and the depth dimension of the first opening groove of any two adjacent first annular pleats are the same.

[0012] In one embodiment, the thickness dimensions of any two adjacent first annular pleats are defined as a and b, respectively, then: b≥101%a, or 0<b≤99%a; the depth dimensions of the first opening grooves of any two adjacent first annular pleats are defined as c and d, respectively, then: d≥105%c, or 0<d≤95%c; and the width dimensions of any two adjacent first annular pleats are the same.

[0013] or,

[0014] If the thickness dimensions of any two adjacent first annular pleats are defined as a and b, then b ≥ 101%a. If the width dimensions of the first opening grooves of any two adjacent first annular pleats are defined as e and f, then f ≥ 105%e, or 0 < f ≤ 95%e. The depth dimensions of the first opening grooves of any two adjacent first annular pleats are the same.

[0015] or,

[0016] The depth dimensions of the first opening grooves of any two adjacent first annular pleats are c and d, respectively, where d ≥ 105%c or 0 < d ≤ 95%c. The width dimensions of the first opening grooves of any two adjacent first annular pleats are e and f, respectively, where f ≥ 105%e or 0 < f ≤ 95%e. The thickness dimensions of any two adjacent first annular pleats are the same.

[0017] In one embodiment, if the thickness dimensions of any two adjacent first annular pleats are defined as a and b, then b ≥ 101%a, or 0 < b ≤ 99%a. If the depth dimensions of the first opening grooves of any two adjacent first annular pleats are defined as c and d, then d ≥ 105%c, or 0 < d ≤ 95%c. If the width dimensions of the first opening grooves of any two adjacent first annular pleats are defined as e and f, then f ≥ 105%e, or 0 < f ≤ 95%e.

[0018] In one embodiment, the thickness dimension of any two adjacent first annular pleats and the width dimension of the first opening groove are the same. The depth dimension of the first opening groove away from the outer edge of the membrane body in any two adjacent first annular pleats is defined as c, and the depth dimension of the other first opening groove is defined as d. Then, d≥105%c, or 0<d≤95%c.

[0019] In one embodiment, the depth and width dimensions of the first opening grooves of any two adjacent first annular folds are the same. The thickness dimension of the first annular fold that is away from the outer edge of the membrane body in any two adjacent first annular folds is defined as a, and the thickness dimension of the other first annular fold is defined as b. Then, b ≥ 101%a, or 0 < b ≤ 99%a.

[0020] In one embodiment, the thickness dimension of any two adjacent first annular pleats and the width dimension of the first opening groove are the same. The depth dimension of the first opening groove away from the outer edge of the membrane body in any two adjacent first annular pleats is defined as e, and the depth dimension of the other first opening groove is defined as f. Then, f ≥ 105%e, or 0 < f ≤ 95%e.

[0021] In one embodiment, the sensitive membrane further includes a second annular pleated portion disposed on the first surface. The interior of the second annular pleated portion forms a second opening groove penetrating the second surface. The number of the second annular pleated portions is at least two, and the at least two second annular pleated portions are sequentially arranged around the central region along the first direction. The shape and size of any two adjacent second annular pleated portions are not exactly the same.

[0022] In one embodiment, each of the first annular pleats is circular, and each of the first annular pleats is concentrically arranged, with any two adjacent first annular pleats spaced apart.

[0023] In one embodiment, the sensitive membrane comprises a plurality of structural layers stacked sequentially along the vibration direction, wherein the plurality of structural layers include an insulating layer and a conductive layer;

[0024] Alternatively, multiple structural layers may be made of the same material.

[0025] This application also proposes a MEMS chip, which includes the aforementioned sensitive membrane.

[0026] This application also proposes a sensor comprising the aforementioned sensitive membrane.

[0027] The technical solution of this application employs a plurality of first annular folds sequentially surrounding the central region on a sensitive membrane. These first annular folds alter the prestress distribution of the sensitive membrane. Specifically, the prestress decreases near the central region and increases near the outer edge, thus improving the mechanical sensitivity of the MEMS microphone chip using this sensitive membrane. Furthermore, since the shapes and sizes of any two adjacent first annular folds are not identical, the mechanical sensitivity of the MEMS microphone chip can be adjusted by modifying the shape of the first annular folds, thereby further enhancing the mechanical sensitivity of the MEMS microphone chip to meet different mechanical sensitivity requirements and expanding the applicability of the sensitive membrane. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0029] Figure 1 is a top view of an embodiment of the sensitive membrane provided in this application;

[0030] Figure 2 is a cross-sectional structural schematic diagram of an embodiment of the sensitive membrane provided in this application;

[0031] Figure 3 is a front view structural schematic diagram of an embodiment of the sensitive membrane provided in this application;

[0032] Figure 4 is a partial structural schematic diagram of an embodiment of the sensitive membrane provided in this application;

[0033] Figure 5 is a partial structural schematic diagram of another embodiment of the sensitive membrane provided in this application;

[0034] Figure 6 is a partial structural schematic diagram of another embodiment of the sensitive membrane provided in this application.

[0035] Explanation of icon numbers:

[0036] 100. Sensitive membrane; 1. Membrane body; 11. Central region; 12. First surface; 13. Second surface; 2. First annular pleated portion; 21. First opening groove; 22. First sidewall; 23. Second sidewall; 24. Bottom wall; 3. Second annular pleated portion; 31. Second opening groove.

[0037] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Embodiments of the present invention

[0038] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0039] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0040] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0041] MEMS microphones are packaged structures consisting of a metal casing and a printed circuit board (PCB). Inside the package, on the surface of the circuit board, is a MEMS microphone chip. Opposite the MEMS microphone chip, on the circuit board, is a sound hole for receiving sound signals. External sound passes through this sound hole to the MEMS microphone chip, achieving the sound intake effect. As the sensitivity requirements for MEMS microphone chips gradually increase, existing MEMS microphone chips are increasingly unable to meet these demands.

[0042] The inventors discovered that the diaphragms of existing MEMS microphone chips generally have smooth surfaces. For diaphragms with smooth surfaces, the prestress distribution is relatively uniform, which leads to the low sensitivity of MEMS microphones using such diaphragms.

[0043] This application proposes a sensitive membrane designed to address the technical problem of how to improve the sensitivity of MEMS microphone chips.

[0044] Please refer to Figures 1 to 5. In one embodiment of this application, the sensitive membrane 100 includes a membrane body 1 and a first annular pleated portion 2. The membrane body 1 includes a first surface 12 and a second surface 13 disposed opposite to each other along the vibration direction of the sensitive membrane 100. The first annular pleated portion 2 is disposed on the second surface 13. A first opening groove 21 penetrating the first surface 12 is formed inside the first annular pleated portion 2. The number of first annular pleated portions 2 is at least two. The membrane body 1 is provided with a central region 11. At least two first annular pleated portions 2 are sequentially arranged around the central region 11 along a first direction. The shape and size of any two adjacent first annular pleated portions 2 are not exactly the same. The shape and size include at least one of the thickness of the first annular pleated portion 2, the depth of the first opening groove 21 along the vibration direction, and the width of the first opening groove 21 along the first direction. The first direction is perpendicular to the vibration direction.

[0045] The sensitive membrane 100 can be applied to microphones or sensors, such as the sensitive membrane 100 in a microphone or the sensitive membrane 100 in other piezoresistive, piezoelectric, or optical sensors. The following explanation uses the sensitive membrane 100 as an example of the sensitive membrane 100 in a MEMS microphone chip.

[0046] The technical solution of this application employs a plurality of first annular pleats 2 sequentially surrounding the central region 11 on the sensitive membrane 100. These first annular pleats 2 alter the prestress distribution of the sensitive membrane 100. Specifically, the prestress near the central region 11 decreases, while the prestress near the outer edge increases, with the first annular pleats 2 serving as the boundary. This change in prestress distribution enhances the mechanical sensitivity of the MEMS microphone chip using this sensitive membrane 100. Furthermore, the addition of multiple first annular pleats 2 to the sensitive membrane 100 increases the effective capacitance area of ​​the MEMS microphone. Here, the effective capacitance area of ​​the MEMS microphone refers to the effective capacitance area formed between the diaphragm and the backplate in a capacitive MEMS microphone.

[0047] The inventors discovered that if each first annular pleat 2 has the same shape and size, that is, if the first annular pleats 2 are regularly distributed on the sensitive membrane 100, the number of first annular pleats 2 can be limited due to the limited space on the diaphragm. Therefore, the solution of improving the mechanical sensitivity of the MEMS microphone chip by setting multiple first annular pleats 2 on the diaphragm has limitations. That is, it is difficult to improve the mechanical sensitivity of the MEMS microphone chip by adding multiple first annular pleats 2 to a certain extent. However, as the requirements for the mechanical sensitivity of the MEMS microphone chip gradually increase, it is necessary to make further breakthroughs based on setting the first annular pleats 2 in order to continue to meet the requirements for mechanical sensitivity.

[0048] This embodiment also adjusts the mechanical sensitivity of the MEMS microphone chip by setting the shape and size of any two adjacent first annular pleats 2 to be different. This could be achieved by different thicknesses of the first annular pleats 2, different depths of the first opening groove 21 along the vibration direction, or different widths of the first opening groove 21 along the first direction. This adjustment allows for the modification of the shape of the first annular pleats 2, thereby further improving the mechanical sensitivity of the MEMS microphone chip to meet different mechanical sensitivity requirements and expanding the applicability of the sensitive film 100. It should be noted that the film body 1 and the first annular pleats 2 are integrally molded components, wherein the first annular pleats 2 can be formed by an etching process. It should also be noted that the outer contour of the first annular pleats 2 can be rectangular or circular, without specific limitations. Furthermore, it should be noted that the vibration direction is the up-down direction shown in Figure 3, and the first direction is the left-right direction shown in Figure 3.

[0049] According to one embodiment of this application, the distance between any two adjacent first annular pleats 2 is not exactly the same. By adjusting the distance between any two adjacent first annular pleats 2, the mechanical sensitivity of the MEMS microphone chip can also be adjusted, thereby further improving the mechanical sensitivity of the MEMS microphone chip.

[0050] Please refer to Figures 3 and 4. In one embodiment, the thickness dimensions of any two adjacent first annular pleats 2 are defined as a and b, respectively. Then, b ≥ 101%a, or 0 < b ≤ 99%a. The depth and width dimensions of the first opening groove 21 of any two adjacent first annular pleats 2 are the same. The thickness dimensions of any two adjacent first annular pleats 2 are different, while the depth and width dimensions of the first opening groove 21 are the same. By adjusting the thickness dimensions of any two adjacent first annular pleats 2, the mechanical sensitivity of the MEMS microphone chip can be adjusted. In this way, the thickness dimensions of the first annular pleats 2 can be changed according to the requirements to improve the mechanical sensitivity of the MEMS microphone chip.

[0051] In one embodiment, the depth dimensions of the first opening groove 21 of any two adjacent first annular pleats 2 are defined as c and d, respectively. Then, d ≥ 105%c, or 0 < d ≤ 95%c. The thickness dimension and the width dimension of the first opening groove 21 of any two adjacent first annular pleats 2 are the same. The depth dimensions of the first opening groove 21 of any two adjacent first annular pleats 2 are different, while the thickness dimension and the width dimension of the first opening groove 21 are the same. By adjusting the depth dimension of the first opening groove 21 of any two adjacent first annular pleats 2, the mechanical sensitivity of the MEMS microphone chip can be adjusted. Thus, the depth dimension of the first opening groove 21 of the first annular pleats 2 can be changed according to the requirements to improve the mechanical sensitivity of the MEMS microphone chip.

[0052] In one embodiment, the width dimensions of the first opening groove 21 of any two adjacent first annular pleats 2 are defined as e and f, respectively. Then, f ≥ 105%e, or 0 < f ≤ 95%e. The thickness dimension and depth dimension of any two adjacent first annular pleats 2 are the same. While the width dimensions of the first opening groove 21 of any two adjacent first annular pleats 2 differ, the thickness dimension and depth dimension of the first opening groove 21 are the same. By adjusting the depth dimension of the first opening groove 21 of any two adjacent first annular pleats 2, the mechanical sensitivity of the MEMS microphone chip can be adjusted. Furthermore, the depth dimension of the first opening groove 21 of the first annular pleats 2 can be changed as needed to improve the mechanical sensitivity of the MEMS microphone chip.

[0053] Referring to Figures 3 and 4, in one embodiment, the thickness dimensions of any two adjacent first annular pleats 2 are defined as a and b, respectively, then: b ≥ 101%a, or 0 < b ≤ 99%a. The depth dimensions of the first opening groove 21 of any two adjacent first annular pleats 2 are defined as c and d, respectively, then: d ≥ 105%c, or 0 < d ≤ 95%c. The width dimensions of any two adjacent first annular pleats 2 are the same; the thickness dimensions of any two adjacent first annular pleats 2 differ, and the first opening groove 21 of any two adjacent first annular pleats 2... The depth dimensions of the opening slot 21 vary, while the width dimensions of the opening slot 21 of any two adjacent first annular pleats 2 are the same. By adjusting the thickness dimensions of any two adjacent first annular pleats 2 and the depth dimensions of the opening slot 21, not only can the mechanical sensitivity of the MEMS microphone chip be adjusted, but the adjustment range of the mechanical sensitivity of the MEMS microphone chip is also expanded. Thus, the thickness dimensions of the first annular pleats 2 and the depth dimensions of the first opening slot 21 can be changed according to requirements to improve the mechanical sensitivity of the MEMS microphone chip.

[0054] In one embodiment, the thickness dimensions of any two adjacent first annular pleats 2 are defined as a and b, respectively, then b ≥ 101%a. The width dimensions of any two adjacent first annular pleats 2's first opening grooves 21 are defined as e and f, respectively, then f ≥ 105%e, or 0 < f ≤ 95%e. The depth dimensions of any two adjacent first annular pleats 2's first opening grooves 21 are the same. The thickness dimensions of any two adjacent first annular pleats 2 differ, and the width dimensions of any two adjacent first annular pleats 2's first opening grooves 21 differ, while the depth dimensions of any two adjacent first annular pleats 2's first opening grooves 21 are the same. By adjusting the thickness dimensions and the width dimensions of any two adjacent first annular pleats 2's first opening grooves 21, not only is the mechanical sensitivity of the MEMS microphone chip adjusted, but the adjustment range of the MEMS microphone chip's mechanical sensitivity is also expanded. Therefore, the thickness dimensions of the first annular pleats 2 and the width dimensions of the first opening grooves 21 can be changed according to requirements to improve the mechanical sensitivity of the MEMS microphone chip.

[0055] In one embodiment, the depth dimensions of the first opening grooves 21 of any two adjacent first annular pleats 2 are c and d, respectively, where d ≥ 105%c or 0 < d ≤ 95%c. The width dimensions of the first opening grooves 21 of any two adjacent first annular pleats 2 are e and f, respectively, where f ≥ 105%e or 0 < f ≤ 95%e. The thickness dimensions of any two adjacent first annular pleats 2 are the same. Since the depth dimensions and width dimensions of the first opening grooves 21 of any two adjacent first annular pleats 2 differ, while the thickness dimensions are the same, adjusting the depth and width dimensions of the first opening grooves 21 of any two adjacent first annular pleats 2 not only adjusts the mechanical sensitivity of the MEMS microphone chip but also expands the adjustment range of the mechanical sensitivity of the MEMS microphone chip. Therefore, the depth and width dimensions of the first opening grooves 21 of the first annular pleats 2 can be changed according to requirements to improve the mechanical sensitivity of the MEMS microphone chip.

[0056] Please refer to Figures 3 and 4. In one embodiment, the thickness dimensions of any two adjacent first annular pleats 2 are defined as a and b, respectively. Then: b ≥ 101%a, or 0 < b ≤ 99%a. The depth dimensions of the first opening grooves 21 of any two adjacent first annular pleats 2 are defined as c and d, respectively. Then: d ≥ 105%c, or 0 < d ≤ 95%c. The width dimensions of the first opening grooves 21 of any two adjacent first annular pleats 2 are defined as e and f, respectively. Then: f ≥ 105%e, or 0 < f ≤ 95%e. The thickness, depth, and width of any two adjacent first annular pleats 2, as well as the first opening groove 21, are different. By adjusting the thickness, depth, and width of any two adjacent first annular pleats 2, the mechanical sensitivity of the MEMS microphone chip can be adjusted, and the adjustment range of the mechanical sensitivity of the MEMS microphone chip can be further expanded. Thus, the thickness, depth, and width of the first annular pleats 2, as well as the first opening groove 21, can be changed as needed to improve the mechanical sensitivity of the MEMS microphone chip.

[0057] Referring to Figure 2, in one embodiment, the thickness and width of any two adjacent first annular pleats 2 are the same. The depth of the first opening groove 21 in any two adjacent first annular pleats 2, away from the outer edge of the membrane body 1, is defined as *c*, and the depth of the other first opening groove 21 is defined as *d*. Then, d ≥ 105%c, or 0 < d ≤ 95%c. Since the thickness and width of any two adjacent first annular pleats 2 are the same, the depth of the first opening groove 21 of each first annular pleat 2 gradually increases or decreases from the central region 11 towards the region away from the central region 11. This allows for adjustment of the mechanical sensitivity of the MEMS microphone chip, and the depth of the first opening groove 21 of any first annular pleat 2 can be changed as needed to improve the mechanical sensitivity of the MEMS microphone chip.

[0058] In one embodiment, the depth and width dimensions of the first opening grooves 21 of any two adjacent first annular pleats 2 are the same. The thickness dimension of the first annular pleat 2 furthest from the outer edge of the membrane body 1 is defined as 'a', and the thickness dimension of the other first annular pleat 2 is defined as 'b'. Then, b ≥ 101%a, or 0 < b ≤ 99%a. Since the depth and width dimensions of the first opening grooves 21 of any two adjacent first annular pleats 2 are the same, and the thickness dimension of each first annular pleat 2 gradually increases or decreases from the central region 11 towards the direction away from the central region 11, the mechanical sensitivity of the MEMS microphone chip can be adjusted. Furthermore, the thickness dimension of any first annular pleat 2 can be changed as needed to improve the mechanical sensitivity of the MEMS microphone chip.

[0059] In one embodiment, the thickness and width of any two adjacent first annular pleats 2 are the same. The depth of the first opening groove 21 in any two adjacent first annular pleats 2, away from the outer edge of the membrane body 1, is defined as e, and the depth of the other first opening groove 21 is defined as f. Then, f ≥ 105%e, or 0 < f ≤ 95%e. Since the thickness and width of any two adjacent first annular pleats 2 are the same, the depth of the first opening groove 21 of each first annular pleat 2 gradually increases or decreases from the central region 11 towards the region away from the central region 11. This allows for adjustment of the mechanical sensitivity of the MEMS microphone chip, and the depth of the first opening groove 21 of any first annular pleat 2 can be changed as needed to improve the mechanical sensitivity of the MEMS microphone chip.

[0060] Referring to Figure 5, in one embodiment, the sensitive membrane 100 further includes a second annular pleated portion 3. The second annular pleated portion 3 is disposed on the first surface 12, and a second opening groove 31 penetrating the second surface 13 is formed inside the second annular pleated portion 3. The number of second annular pleated portions 3 is at least two, and at least two second annular pleated portions 3 are sequentially arranged around the central region 11 along a first direction. The shapes and sizes of any two adjacent second annular pleated portions 3 are not exactly the same. By setting the second annular pleated portions 3, the prestress distribution on the sensitive membrane 100 is further changed. By adjusting the positions of the first annular pleated portion 2 and the second annular pleated portion 3, the mechanical sensitivity of the MEMS microphone chip is improved. On this basis, the mechanical sensitivity of the MEMS microphone chip can be further adjusted by the fact that the shapes and sizes of any two adjacent second annular pleated portions 3 are not exactly the same, so as to meet the needs of different sensitivity and expand the applicability of the sensitive membrane 100. It should be noted that the shape and size of the second annular pleated portion 3 includes at least one of the thickness of the second annular pleated portion 3 and the depth and width of the second opening groove 31.

[0061] Referring to Figure 6, according to an embodiment of this application, each first annular pleated portion 2 includes a first sidewall 22, a second sidewall 23, and a bottom wall 24 connecting the first sidewall 22 and the second sidewall 23. The thickness dimensions include a first thickness dimension, a second thickness dimension, and a third thickness dimension. The dimension of the first sidewall 22 in a first direction is the first thickness dimension, the dimension of the second sidewall 23 in the first direction is the second thickness dimension, and the dimension of the bottom wall 24 in the vibration direction is the third thickness dimension. The first, second, and third thickness dimensions of each annular recess are the same, or the first, second, and third thickness dimensions of each annular recess are not completely identical. By adjusting the first, second, and third thickness dimensions respectively, the mechanical sensitivity of the MEMS microphone chip is further adjusted to increase the mechanical sensitivity of the MEMS microphone chip. The first thickness dimension is a1 as shown in Figure 6, the second thickness dimension is a2 as shown in Figure 6, and the third thickness dimension is a3 as shown in Figure 6.

[0062] In one embodiment, each of the first annular pleats 2 is circular, and the first annular pleats 2 are concentrically arranged, with any two adjacent first annular pleats 2 spaced apart. The circular shape of each first annular pleat 2 avoids stress concentration caused by irregular structures.

[0063] In one embodiment, the sensitive membrane 100 includes a plurality of structural layers stacked sequentially along the vibration direction, the plurality of structural layers including an insulating layer and a conductive layer; wherein the material of the conductive layer can be a semiconductor material or a conductor material, and the material of the insulating layer can be an oxide, a nitride or other insulating material.

[0064] In one embodiment, multiple structural layers are made of the same material. Using the same material for multiple structural layers facilitates manufacturing and processing.

[0065] This application also proposes a MEMS chip, which includes the aforementioned sensitive membrane, which is a diaphragm used to receive sound pressure signals. Since the MEMS chip employs all the technical solutions of the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, and will not be elaborated further here. It should be noted that this sensitive membrane can also be applied to CMOS chips.

[0066] This application also proposes a sensor, which includes the aforementioned sensitive membrane 100. Since the sensor employs all the technical solutions of all the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated upon here. The sensor can be a pressure sensor or a sound sensor.

[0067] The above description is merely an exemplary embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the technical concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A sensitive membrane, wherein, The sensitive membrane includes a membrane body and a first annular pleated portion. The membrane body includes a first surface and a second surface disposed opposite to each other along the vibration direction of the sensitive membrane. The first annular pleated portion is disposed on the second surface. A first opening groove penetrating the first surface is formed inside the first annular pleated portion. The number of the first annular pleated portions is at least two. The membrane body is provided with a central region. At least two first annular pleated portions are sequentially arranged around the central region along a first direction. The shape and size of any two adjacent first annular pleated portions are not exactly the same. The shape and size include at least one of the thickness of the first annular pleated portion, the depth of the first opening groove along the vibration direction, and the width of the first opening groove along the first direction. The first direction is perpendicular to the vibration direction.

2. The sensitive membrane as described in claim 1, wherein: If the thickness dimensions of any two adjacent first annular pleats are defined as a and b, then: b ≥ 101%a, or 0 < b ≤ 99%a; the depth dimension and the width dimension of the first opening groove of any two adjacent first annular pleats are the same. or, If the depth dimensions of the first opening groove of any two adjacent first annular pleats are defined as c and d respectively, then: d≥105%c, or 0<d≤95%c, and the thickness dimension and the width dimension of the first opening groove of any two adjacent first annular pleats are the same. or, If the width dimensions of the first opening groove of any two adjacent first annular pleats are defined as e and f respectively, then: f≥105%e, or 0<f≤95%e, and the thickness dimension and the depth dimension of the first opening groove of any two adjacent first annular pleats are the same.

3. The sensitive membrane as described in claim 1, wherein, If the thickness dimensions of any two adjacent first annular pleats are defined as a and b, then: b ≥ 101%a, or 0 < b ≤ 99%a. If the depth dimensions of the first opening grooves of any two adjacent first annular pleats are defined as c and d, then: d ≥ 105%c, or 0 < d ≤ 95%c. The width dimensions of any two adjacent first annular pleats are the same. or, If the thickness dimensions of any two adjacent first annular pleats are defined as a and b, then b ≥ 101%a. If the width dimensions of the first opening grooves of any two adjacent first annular pleats are defined as e and f, then f ≥ 105%e, or 0 < f ≤ 95%e. The depth dimensions of the first opening grooves of any two adjacent first annular pleats are the same. or, The depth dimensions of the first opening grooves of any two adjacent first annular pleats are c and d, respectively, where d ≥ 105%c or 0 < d ≤ 95%c. The width dimensions of the first opening grooves of any two adjacent first annular pleats are e and f, respectively, where f ≥ 105%e or 0 < f ≤ 95%e. The thickness dimensions of any two adjacent first annular pleats are the same.

4. The sensitive membrane as described in claim 1, wherein, If the thickness dimensions of any two adjacent first annular pleats are defined as a and b, then: b ≥ 101%a, or 0 < b ≤ 99%a. If the depth dimensions of the first opening grooves of any two adjacent first annular pleats are defined as c and d, then: d ≥ 105%c, or 0 < d ≤ 95%c. If the width dimensions of the first opening grooves of any two adjacent first annular pleats are defined as e and f, then: f ≥ 105%e, or 0 < f ≤ 95%e.

5. The sensitive membrane as described in claim 1, wherein, The thickness dimension and the width dimension of the first opening groove are the same for any two adjacent first annular folds. The depth dimension of the first opening groove away from the outer edge of the membrane body in any two adjacent first annular folds is defined as c, and the depth dimension of the other first opening groove is defined as d. Then: d≥105%c, or 0<d≤95%c.

6. The sensitive membrane as described in claim 1, wherein, The depth and width of the first opening groove of any two adjacent first annular folds are the same. The thickness of the first annular fold that is away from the outer edge of the membrane body in any two adjacent first annular folds is defined as a, and the thickness of the other first annular fold is defined as b. Then we have: b ≥ 101%a, or 0 < b ≤ 99%a.

7. The sensitive membrane as described in claim 1, wherein, The thickness dimension of any two adjacent first annular folds and the width dimension of the first opening groove are the same. The depth dimension of the first opening groove away from the outer edge of the membrane body in any two adjacent first annular folds is defined as e, and the depth dimension of the other first opening groove is defined as f. Then: f≥105%e, or 0<f≤95%e.

8. The sensitive membrane according to any one of claims 1 to 7, wherein, The sensitive membrane further includes a second annular pleated portion, which is disposed on the first surface. The interior of the second annular pleated portion forms a second opening groove that penetrates the second surface. The number of the second annular pleated portions is at least two, and at least two second annular pleated portions are sequentially arranged around the central region along the first direction. The shape and size of any two adjacent second annular pleated portions are not exactly the same.

9. The sensitive membrane according to any one of claims 1 to 7, wherein, Each of the first annular pleats is circular, and each of the first annular pleats is concentrically arranged, with any two adjacent first annular pleats spaced apart.

10. The sensitive membrane according to any one of claims 1 to 7, wherein, The sensitive membrane includes a plurality of structural layers stacked sequentially along the vibration direction, and the plurality of structural layers include an insulating layer and a conductive layer; Alternatively, multiple structural layers may be made of the same material.

11. A MEMS chip, wherein, The MEMS chip includes a sensitive membrane as described in any one of claims 1 to 10.

12. A sensor, wherein, The sensor includes a sensitive membrane as described in any one of claims 1 to 10.

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