MEMS chip, MEMS system and electronic equipment

Abstract

The embodiment of the invention provides an MEMS chip, an MEMS system and electronic equipment. The MEMS chip comprises a back polar plate, and the back polar plate is provided with a fixed supporting area which is used for being fixedly connected with a supporting structure; the acoustic action region is arranged opposite to the vibrating diaphragm to form an acoustic capacitance structure; wherein the acoustic action area is provided with acoustic through holes, and at least part of the acoustic through holes form a gradually-changed aperture array area; in the gradually-changed aperture array area, the characteristic apertures of the acoustic through holes are continuously and progressively decreased towards the edge direction along the radial direction of the gradually-changed aperture array area; the characteristic aperture is defined as the diameter of a minimum circumcircle determined by taking the geometrical shape of the acoustic through hole as a reference.

Description

Technical Field

[0001] This application relates to the field of electronic product technology, and more specifically, to a MEMS chip, a MEMS system, and an electronic device. Background Technology

[0002] MEMS (Micro-Electro-Mechanical Systems) chips are widely used in various electronic devices, such as smartphones, smart speakers, and hearing aids. In the structure of a MEMS chip, the backplate is one of the core components, and its performance and reliability directly affect the overall performance of the microphone.

[0003] However, existing porous backplane MEMS chips suffer from significant reliability issues, especially in large-size chips. Specifically, during airflow tests, a large airflow can cause the diaphragm to vibrate significantly under sound pressure, potentially leading to contact with the backplane. The backplane then needs to withstand the impact and resist deformation. However, due to the inherent structural characteristics and material properties of porous backplanes, their resistance to deformation is limited. Repeated impacts from the diaphragm can cause deformation or even damage to the backplane, affecting the microphone's normal operation. Furthermore, drop tests have revealed reliability vulnerabilities caused by inadequate backplane design. When the chip is subjected to a drop impact, stress concentration may occur on the backplane. Due to the complexity of the porous backplane structure, stress distribution is often uneven, and in some localized areas, the stress may exceed the material's tolerance limit. If this occurs, the backplane is prone to fracture in these stress concentration areas, leading to chip failure.

[0004] In view of the problems existing in the prior art, it is necessary to provide a new technical solution to solve the technical defects of poor back electrode plate reliability and easy breakage of the back electrode plate in the existing MEMS chip. Summary of the Invention

[0005] The purpose of this application is to provide a MEMS chip, MEMS system, and electronic device to solve the technical defects of poor back electrode plate reliability and easy breakage of the back electrode plate in existing MEMS chips.

[0006] According to a first aspect of this application, a MEMS chip is provided. The MEMS chip includes: Back electrode plate, the back electrode plate having: Fixed support area, used for fixed connection with the support structure; The acoustic action zone is positioned opposite the diaphragm to form an acoustic capacitor structure; The acoustic action area is provided with acoustic through holes, and at least a portion of the acoustic through holes constitute a gradient aperture array area; within the gradient aperture array area, the characteristic aperture of the acoustic through holes is continuously decreasing along the radial direction of the gradient aperture array area toward the edge. The characteristic aperture is defined as the diameter of the smallest circumcircle determined based on the geometry of the acoustic through-hole.

[0007] Optionally, within the gradient aperture array region, all acoustic through holes have the same geometry, or within the gradient aperture array region, acoustic through holes with the same characteristic aperture have the same geometry.

[0008] Optionally, within the gradient aperture array region, the acoustic through-holes are distributed in a graded ring shape according to the characteristic aperture size; The hierarchical annular distribution specifically satisfies the following: In acoustic through-holes with the same characteristic aperture, the line connecting the centers of the characteristic apertures of all acoustic through-holes forms a first closed ring, and the number n of the first closed ring satisfies: n≥3.

[0009] Optionally, the first closed loop is a circular ring or a polygonal ring; wherein, when the first closed loop is a polygonal ring, the number of its sides N satisfies: N≥4.

[0010] Optionally, along the radial direction of the gradient aperture array region, the characteristic aperture difference ΔD of two adjacent acoustic through holes satisfies: 0.2μm≤ΔD≤10μm.

[0011] Optionally, the acoustic action area includes a main body area, in which the characteristic aperture size of all acoustic through holes is constant, wherein the gradient aperture array area is distributed in the peripheral area of ​​the main body area.

[0012] Optionally, within the main body area, a second closed ring is formed by enclosing the centers of the characteristic apertures of the acoustic through holes arranged adjacent to each other along the circumference of the back electrode plate, with the geometric center of the back electrode plate as a reference. Within the gradient aperture array region, in acoustic through-holes with the same characteristic aperture, the line connecting the centers of the characteristic apertures of all acoustic through-holes forms a first closed loop. The first closed ring and the second closed ring have the same shape, or they have relatively parallel sides, or they have different shapes.

[0013] Optionally, the second closed loop is one of a circular ring, a polygonal ring, or a polygonal-like ring, wherein when the second closed loop is a polygonal ring or a polygonal-like ring, the number of its sides N satisfies: N≥4.

[0014] Optionally, if the first closed loop and the second closed loop are different, the first closed loop is a circular ring and the second closed loop is a polygonal ring.

[0015] Optionally, when the first closed ring is a circular ring and the second closed ring is a polygonal ring, a transition region is formed between the first closed ring and the second closed ring. A first set of transition holes is provided in the transition zone near the second closed annular region, and the first set of transition holes is randomly distributed along the circumferential direction of the transition zone; and... A second set of transition holes is provided in the transition zone near the first closed annular region. The second set of transition holes is evenly distributed in a circular pattern along the circumferential direction of the transition zone.

[0016] Optionally, the main area is defined as a region that satisfies any of the following conditions: Located at the geometric center of the back electrode plate; With the geometric center of the back electrode plate as the origin, the ratio of its coverage area S1 to the total area S0 of the opening region of the back electrode plate satisfies: .

[0017] Optionally, the main body region and the gradient aperture array region are arranged adjacent to each other, and at least one first acoustic through hole is provided on the side of the main body region closer to the gradient aperture array region; At least one second acoustic through-hole is provided on the side of the gradient aperture array region near the main body region, wherein the characteristic aperture size of the second acoustic through-hole is less than or equal to the characteristic aperture size of the first acoustic through-hole. Optionally, the gradient aperture array region includes a first sub-array region and a second sub-array region, wherein the first sub-array region is disposed closer to the main body region relative to the second sub-array region; In the first sub-array region, a first closed loop formed by connecting the centers of the characteristic apertures of acoustic through-holes with the same characteristic aperture has relatively parallel sides to a second closed loop formed within the main body region, which is formed by the centers of the characteristic apertures of the acoustic through-holes arranged adjacent to each other along the circumference of the back electrode plate with reference to the geometric center of the back electrode plate; and In the second sub-array region, the first closed loop formed by connecting the centers of the characteristic apertures of acoustic through holes with the same characteristic aperture is different from the shape of the second closed loop formed by the centers of the characteristic apertures of the acoustic through holes arranged adjacent to each other along the circumference of the back electrode plate, with the geometric center of the back electrode plate as the reference.

[0018] Optionally, a transition region is formed between the first sub-array region and the second sub-array region, and a first set of transition holes is formed in the region of the transition region near the first sub-array region. The first set of transition holes is randomly distributed along the circumferential direction of the transition region. A second set of transition holes is provided in the region of the transition zone near the second sub-array region. The second set of transition holes is evenly distributed in a ring along the circumferential direction of the transition zone.

[0019] Optionally, in the second sub-array region, the maximum characteristic aperture of the acoustic via is smaller than the minimum characteristic aperture of the acoustic via in the first sub-array region.

[0020] Optionally, the apertures of each transition hole in the first group of transition holes are different, and the aperture of each transition hole is less than or equal to the minimum characteristic aperture of the acoustic through hole in the gradient aperture array region. The transition holes in the second group of transition holes have the same diameter and are smaller than the minimum characteristic diameter of the acoustic through holes in the gradient aperture array region.

[0021] According to a second aspect of this application, a MEMS system is provided. The MEMS system includes the MEMS chip described in the first aspect.

[0022] According to a third aspect of this application, an electronic device is provided. The electronic device includes the MEMS system described in the second aspect.

[0023] One technical advantage of this application is: In the technical solution provided in this application embodiment, the design of the gradient aperture array region effectively optimizes the stress distribution in each region of the back electrode plate, avoiding excessive local stress concentration.

[0024] Other features and advantages of this specification will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0025] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of this specification and, together with their description, serve to explain the principles of this specification.

[0026] Figure 1 The diagram shows the layout structure of a traditional backplate.

[0027] Figures 2a-2b The diagram shown is a structural schematic of the first type of back electrode plate provided in the embodiment of this application.

[0028] Figures 3a-3c The diagram shown is a schematic diagram of the acoustic through-hole provided in an embodiment of this application.

[0029] Figure 4 The diagram shown is a structural schematic of the second type of back electrode plate provided in an embodiment of this application.

[0030] Figure 5 The diagram shown is a structural schematic of the third type of back electrode plate provided in the embodiment of this application.

[0031] Figure 6 The diagram shown is a structural schematic of the fourth type of back electrode plate provided in the embodiments of this application.

[0032] Figure 7 As shown Figure 6 Global structural diagram of the middle back electrode plate.

[0033] Explanation of reference numerals in the attached figures: 1. Backplate; 10. Acoustic through-hole; 101. First acoustic through-hole; 102. Second acoustic through-hole; 11. Fixed support area; 12. Acoustic action area; 120. Gradient aperture array area; 121. Main body area; 122. First subarray region; 123. Second subarray region; 124. First closed ring; 125. Second closed ring; 13. Transition zone; 131. First group of transition holes; 132. Second group of transition holes; 14. Edge transition area. Detailed Implementation

[0034] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0035] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0036] Technologies and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such technologies and equipment should be considered part of the specification.

[0037] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0038] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0039] The technical solution of this application will be further described below with reference to the embodiments and accompanying drawings.

[0040] This application provides a MEMS chip. (Refer to...) Figures 2a-2b ,as well as Figures 4-7 The MEMS chip includes: a back electrode 1, wherein the back electrode 1 has: Fixed support area 11, used for fixed connection with the support structure; The acoustic action area 12 is positioned opposite the diaphragm to form an acoustic capacitor structure; The acoustic action area 12 is provided with acoustic through holes 10, and at least a portion of the acoustic through holes 10 constitute a gradient aperture array area 120. Within the gradient aperture array area 120, the characteristic aperture of the acoustic through holes 10 is continuously decreasing along the radial direction of the gradient aperture array area 120 toward the edge. The characteristic aperture is defined as the diameter of the smallest circumcircle determined based on the geometry of the acoustic through-hole 10.

[0041] In the embodiments of this application, the structure of the back electrode plate 1 of the MEMS chip has been improved. The improved back electrode plate 1 can achieve uniform stress distribution during its use. Specifically, this structural design effectively optimizes the stress distribution in various regions of the back electrode plate 1, avoiding excessive local stress concentration.

[0042] Meanwhile, when the back electrode 1 is subjected to external forces such as diaphragm contact, this improved structure significantly enhances the deformation resistance of the back electrode 1. When subjected to external forces, the back electrode 1 can better maintain its shape and structural stability, reducing deformation caused by external forces, thereby ensuring the reliability and performance stability of the MEMS chip.

[0043] Specifically, in the MEMS chip structure, the back electrode 1 is divided into a fixed support area 11 and an acoustic action area 12, depending on whether the back electrode 1 is connected to the support structure.

[0044] Reference Figure 5 The main function of the fixed support area 11 is to achieve a stable connection between the back electrode plate 1 and the support structure. Through this fixed connection, the back electrode plate 1 can maintain a stable position in the chip. During the operation of the MEMS chip, it may be affected by various external forces or environmental factors. The fixed support area 11 ensures that the back electrode plate 1 will not be displaced or loosened, thereby ensuring the normal operation of the chip.

[0045] Reference Figure 2a and reference Figures 4-7The acoustic region 12 is the area where the MEMS chip performs sound-to-electrical conversion. When sound waves act on the diaphragm, the diaphragm vibrates, causing a change in the distance between it and the acoustic region 12, which in turn alters the capacitance. By detecting this change in capacitance, the acoustic signal can be converted into an electrical signal, thus enabling sound acquisition and conversion.

[0046] In this embodiment, acoustic through-holes 10 are provided in the acoustic action area 12, and at least a portion of the acoustic through-holes 10 constitute a gradient aperture array area 120. Here, "at least a portion of the acoustic through-holes 10 constitute a gradient aperture array area 120" includes two possible scenarios: First, refer to Figure 4 , refer to Figure 6 and Figure 7 Within the acoustic action zone 12, only a portion of the acoustic through holes 10 are arranged according to a specific rule to form the gradient aperture array zone 120. In this case, the gradient aperture array zone 120 is often distributed in the edge region that is relatively far from the geometric center of the back electrode plate 1.

[0047] Secondly, almost all the acoustic apertures 10 within the acoustic region 120 are configured in a manner that meets the requirements of the gradient aperture array region 120. For example, in Figure 5 In the acoustic action zone 12, the acoustic through-hole 10 within the edge transition region 14 is arranged according to... Figure 6 When the acoustic through-hole 10 is set in the middle edge transition region 14, Figure 5 Almost all the acoustic through-holes 10 in the middle acoustic region 12 are configured in a manner that meets the requirements of the gradient aperture array region 120.

[0048] In this embodiment, the characteristic aperture of each acoustic aperture 10 is continuously decreasing from the center to the edge along the radial direction of the gradient aperture array region 120. The characteristic aperture is the diameter of the smallest circumscribed circle determined based on the geometry of the acoustic aperture 10.

[0049] Reference Figures 3a-3c The acoustic through-hole 10 has the following geometric shapes: 1. Circular: The diameter of the circular through-hole 10 is the smallest circumscribed circle diameter. 2. Hexagonal (regular hexagon): The length of the line connecting the opposite corners of the hexagon is the smallest circumscribed circle diameter. 3. Elliptical: The major axis of the ellipse is the smallest circumscribed circle diameter.

[0050] This continuously decreasing characteristic aperture distribution helps to achieve a more uniform stress distribution on the back electrode plate 1.

[0051] For example, the acoustic via 10 has a relatively large characteristic aperture in the region closer to the geometric center of the back electrode 1. When the MEMS chip is working and the back electrode 1 is subjected to external forces such as diaphragm vibration, the larger aperture provides a wider channel for stress transmission. When stress enters this region, it can pass through these large-aperture vias more smoothly and will not accumulate rapidly in a localized area.

[0052] As the radial direction advances from the center to the edge, the characteristic aperture of the acoustic via 10 continuously decreases. In the region relatively far from the geometric center of the back electrode 1, the smaller aperture further refines and disperses the stress. The smaller aperture restricts the stress transmission path, dispersing the stress to more minute areas. This refinement and dispersion process reduces the local stress level. Through this continuously decreasing aperture design, the stress is more uniformly and rationally dispersed throughout the gradient aperture array region 120, effectively reducing the risk of local stress concentration.

[0053] In other words, this aperture design allows stress to be more reasonably distributed at different locations, reducing the risk of local stress concentration, thereby enhancing the overall structural stability of the back electrode plate 1 and reducing the possibility of deformation or damage to the back electrode plate 1 due to excessive stress.

[0054] Furthermore, the design of the gradient aperture array region 120 enables the back electrode plate 1 to better resist deformation when subjected to external forces such as diaphragm contact. For example, the uniform stress distribution and reasonable aperture layout help maintain the shape and dimensional stability of the back electrode plate 1, ensuring that the gap between it and the diaphragm is always kept within a suitable range, maintaining the normal operation of the acoustic capacitor structure, and extending the service life of the MEMS chip.

[0055] In other words, when the back electrode 1 is subjected to external force, the stress is evenly distributed, preventing excessive local deformation and ensuring that the gap between the back electrode 1 and the diaphragm remains within a suitable range. If the gap is too large, the sensitivity of the acoustic capacitor will decrease; if the gap is too small, it may cause adhesion between the diaphragm and the back electrode 1, affecting the normal operation of the chip. Therefore, the continuously decreasing aperture distribution maintains a suitable gap, ensuring the stability and reliability of the acoustic capacitor structure.

[0056] Therefore, in this embodiment, the effect of the MEMS chip on structural stability is reflected in the fact that the design of the gradient aperture array region 120 effectively optimizes the stress distribution in each region of the back electrode plate 1, avoiding excessive local stress concentration.

[0057] The acoustic benefits of the MEMS chip are manifested in the design of the gradient aperture array region 120, which causes the characteristic aperture of the acoustic via 10 to continuously decrease towards the edge in the radial direction. This aperture distribution can regulate the propagation of sound waves on the back electrode 1, allowing sound waves of different frequencies to pass through the acoustic via 10 more effectively and interact with the diaphragm, thereby significantly improving the frequency response characteristics of the MEMS chip and enabling it to maintain high sensitivity and stability over a wider frequency range, meeting the requirements of high-quality audio acquisition.

[0058] In one specific embodiment, refer to Figure 1 This is a traditional back electrode plate structure. In a traditional back electrode plate, the shape and diameter of each acoustic through-hole are consistent. Simulation results show that significant stress concentration zones form in certain areas of the traditional back electrode plate. Figure 1 (Stress concentration occurs in the red area). Figure 1 In the middle, the stress percentage of the back plate is 100%.

[0059] Reference Figure 2a and Figure 2b This is a structural diagram of the improved back electrode plate 1 of this application. Figure 2a This is a partial structural schematic diagram of the improved back electrode plate 1. Figure 2b It indicates Figure 2a A schematic diagram showing the dimensions of the acoustic vias 10 in the gradient aperture array region 120 of the back electrode plate 1. The gradient aperture array region 120 forms a three-level annular distribution. Specifically, the characteristic aperture of the acoustic vias 10 in the first-level annular distribution is L1, the characteristic aperture of the acoustic vias 10 in the second-level annular distribution is L2, and the characteristic aperture of the acoustic vias 10 in the third-level annular distribution is L3, where L1 > L2 > L3. In this case, Figure 2a The stress percentage of back plate 1 is 79%, which is 21% lower than that of traditional back plate 1, and the stress concentration is significantly improved.

[0060] In another specific embodiment, refer to Figure 5 As indicated by the arrows in the left-hand diagram, the characteristic aperture size of the acoustic via 10 gradually decreases in the radial direction. (Refer to...) Figure 5 In the right figure, the stress concentration phenomenon of back plate 1 is not obvious, which reduces the risk of local stress concentration.

[0061] In other words, the back electrode plate 1 provided in this application effectively optimizes the stress distribution in each region of the back electrode plate 1 through the design of the gradient aperture array region 120, avoiding excessive local stress concentration.

[0062] According to a further embodiment of this application, within the gradient aperture array region 120, all acoustic through holes 10 have the same geometry, or within the gradient aperture array region 120, acoustic through holes 10 with the same characteristic aperture have the same geometry.

[0063] In the embodiments of this application, within the gradient aperture array region 120, all acoustic through holes 10 have the same geometry, or acoustic through holes 10 with the same characteristic aperture have the same geometry.

[0064] For example, refer to Figures 3a-3c The geometry of the acoustic aperture 10 can be circular, polygonal (e.g., hexagonal), elliptical, or quasi-elliptical.

[0065] For example, within the gradient aperture array region 120, acoustic through holes with the same characteristic aperture have the same geometry. For instance, in the gradient aperture array region 120, a graded ring distribution is formed, and acoustic through holes 10 at the same grade (that is, acoustic through holes that enclose the same first closed ring) have the same geometry.

[0066] In this embodiment, the fact that the acoustic through-holes 10 have the same geometry helps to ensure that the propagation characteristics of sound waves when passing through these through-holes have a certain regularity and consistency, reducing stress interference caused by shape differences and improving acoustic performance.

[0067] Specifically, within the gradient aperture array region 120, the lines connecting the centers of acoustic vias 10 with the same characteristic aperture form a first closed loop. All acoustic vias 10 enclosing the same first closed loop have the same geometric shape. From an acoustic principle perspective, acoustic vias with the same geometric shape exhibit similar patterns in sound wave absorption and transmission. When sound waves pass through these vias, similar acoustic responses are generated at each via, ensuring a high degree of regularity and consistency in the characteristics of the sound waves throughout the propagation process. From a mechanical perspective, acoustic vias with the same shape generate a more uniform stress distribution when subjected to sound waves, reducing local stress concentration caused by shape differences and thus mitigating the adverse effects of stress interference on acoustic performance.

[0068] For example, when the back electrode 1 of the MEMS chip is subjected to external forces such as diaphragm vibration during operation, stress is generated and distributed in the acoustic region 12. Because the acoustic vias 10 have a consistent geometry, stress does not cause localized stress abrupt changes due to shape differences when passing through these via regions. Different via shapes may cause stress to be transmitted and concentrated in different ways at different locations, while vias with the same geometry ensure a consistent stress transmission path. This consistency avoids excessive stress concentration at certain locations, effectively reducing stress concentration. Simultaneously, the uniform stress transmission path promotes a more rational distribution of stress throughout the gradient aperture array region 120, achieving uniform stress distribution, enhancing the structural stability of the back electrode 1, and improving the reliability and lifespan of the MEMS chip.

[0069] Furthermore, since all acoustic apertures 10 have the same geometry and a gradually varying aperture distribution, acoustic reflections and interference that may occur due to abrupt or irregular aperture distribution are avoided. Sound waves can propagate more smoothly in the acoustic region 12, reducing unnecessary acoustic interference, improving the purity and accuracy of the acoustic signal, and contributing to enhanced performance of the MEMS system in complex acoustic environments.

[0070] According to the embodiments of this application, refer to Figure 2a , Figure 4 , Figure 5 , Figure 6 and Figure 7 Within the gradient aperture array region 120, the acoustic through holes 10 are distributed in a graded ring shape according to the characteristic aperture size; The hierarchical annular distribution specifically satisfies the following: in acoustic through holes 10 with the same characteristic aperture, the line connecting the centers of the characteristic apertures of all acoustic through holes 10 forms a first closed ring 124, and the number n of the first closed ring 124 satisfies: n≥3, wherein the number of the first closed ring 124 corresponds to the number of levels in the hierarchical annular distribution.

[0071] In this embodiment, reference is made to Figure 2a and Figure 2b A gradient aperture array region 120 is formed in the back electrode plate 1 at a position far from its geometric center, specifically forming a three-level ring distribution. (Refer to...) Figure 2b Within the gradient aperture array region 120, the characteristic aperture L of the acoustic through-hole 10 satisfies: L1 > L2 > L3.

[0072] Reference Figure 4 A gradient aperture array region 120 is formed in the back electrode plate 1 at a position away from its geometric center, specifically forming a three-level annular distribution (a1, a2, and a3). Within the gradient aperture array region 120, the characteristic aperture L of the acoustic through hole 10 satisfies: L1 > L2 > L3.

[0073] Reference Figure 6 A gradient aperture array region 120 is formed in the back electrode plate 1 at a position away from its geometric center. In this figure, there are two gradient aperture array regions 120. One of the gradient aperture array regions 120 (first sub-array region 122) forms a three-level annular distribution (b1, b2, and b3). Within this gradient aperture array region 120, the characteristic aperture L of the acoustic through-hole 10 satisfies: L 11 >L 12 >L 13 Another gradient aperture array region 120 (second sub-array region 123) forms a three-level annular distribution (a1, a2, and a3). Within this gradient aperture array region 120, the characteristic aperture L of the acoustic through-hole 10 satisfies: L 21 >L 22 >L 23 .

[0074] In this embodiment, within the gradient aperture array region 120, acoustic vias 10 with the same characteristic aperture are categorized. For each category of acoustic vias 10 with the same characteristic aperture, the centers of all the characteristic apertures of the acoustic vias 10 are connected sequentially to form a first closed ring 124 (a virtual component, not present in the back electrode plate 1). Furthermore, the number n of such first closed rings 124 is limited to be greater than or equal to 3. This means that within the gradient aperture array region 120, there will be at least three closed ring structures corresponding to different characteristic aperture levels. The acoustic vias 10 within each ring structure have a consistent characteristic aperture, while the characteristic apertures of the acoustic vias 10 differ between different ring structures, thus forming a hierarchical and ring-shaped distribution pattern.

[0075] The acoustic vias 10 are designed with a hierarchical annular distribution based on their characteristic aperture sizes, which allows for a more reasonable distribution of stress on the back electrode plate 1. The annular distribution regions with different characteristic aperture sizes correspond to different stress-bearing capacities. When external forces are applied, the stress is transmitted and dispersed according to the characteristics of each annular region. Since the number of the first closed annular rings 124 is n≥3, for example, n is in the range of 3 to 20 or more, it ensures that there are enough levels to finely adjust the stress distribution while avoiding structural complexity due to excessive levels. This design effectively reduces the risk of localized stress concentration, enhances the overall structural stability of the back electrode plate 1, and reduces the possibility of deformation or damage to the back electrode plate 1 due to excessive stress, thereby improving the reliability and lifespan of the MEMS chip.

[0076] Furthermore, in terms of acoustic performance, the propagation path of sound waves in the acoustic region 12 can be optimized through a reasonable hierarchical ring arrangement. With at least three first closed rings 124 distributed, sound waves of different frequencies can be processed in a targeted manner. This helps reduce interference and distortion during sound wave propagation, improves the transmission efficiency and quality of acoustic signals, and enables the MEMS chip to more accurately achieve sound-to-electric conversion, providing clearer and more accurate raw signals for subsequent signal processing.

[0077] According to an embodiment of this application, the first closed ring 124 is a circular ring or a polygonal ring; wherein, when the first closed ring 124 is a polygonal ring, its number of sides N satisfies: N≥4.

[0078] Among them, reference Figure 7 A polygonal shape can be understood as including the edges of a polygon and the wavy part connecting adjacent edges. That is, a polygonal shape is a shape between a torus and a regular polygon.

[0079] In this way, when the acoustic action area 12 includes the main body area 121, by designing the first closed ring 124 as a polygonal ring to achieve shape compensation, stress concentration can be avoided at the junction of the abrupt changes in the arrangement of acoustic through holes in the main body area 121 and the arrangement of acoustic through holes in the gradient aperture array area 120.

[0080] For example, the second closed loop 125 is a circular ring, and the first closed loop 124 is a polygon-like shape; shape compensation is achieved through the polygon-like loop. Alternatively, the second closed loop 125 is a regular polygonal loop, and the first closed loop 124 is a polygon-like shape; the shape difference between the second closed loop 125 and the first closed loop 124 is compensated for by the polygon-like loop. Or refer to... Figure 7 The second closed loop is a regular polygon of 125, and one set of first closed loops 124 is a ring. Another set of first closed loops 124 in the form of a polygonal ring is set between the second closed loop 125 and the first closed loops 124. The first closed loops 124 in the form of a polygonal ring compensate for the shape difference between the ring and the regular polygon.

[0081] For example, a polygon-like shape is a hexagon-like shape, which includes six sides and wavy sections connecting adjacent sides, wherein the hexagon-like shape includes six wavy sections. A polygon-like shape is a pentagon-like shape, which includes five sides and wavy sections connecting adjacent sides, wherein the pentagon-like shape includes five wavy sections.

[0082] Reference Figure 2a The diagram shows a partial structural schematic of the first type of back electrode plate 1. In this diagram, the first closed ring 124 formed by the acoustic through-holes 10 of the same characteristic size is a hexagonal ring. Figure 7As shown, it illustrates Figure 2a The structure of a medium-sized polygonal ring.

[0083] Reference Figure 4 The diagram shows a partial structural schematic of the second type of back electrode plate 1. In this diagram, the first closed ring structure 124 formed by the acoustic through holes 10 with the same characteristic size is a ring.

[0084] Reference Figure 5 The diagram shows a partial structural schematic of the third type of back electrode plate 1. In this diagram, the first closed ring 124 formed by the acoustic through-holes 10 of the same characteristic size is a hexagonal ring. Figure 7 As shown, it illustrates Figure 5 The structure of a medium-sized polygonal ring.

[0085] Reference Figure 6 The diagram shows a partial structural schematic of the fourth type of back electrode. In this diagram, there are two regions of gradient aperture array 120. In one type of gradient aperture array 120, the first closed ring 124 formed by the acoustic through holes 10 of the same characteristic size is a hexagonal ring. In the other type of gradient aperture array 120, the first closed ring 124 formed by the acoustic through holes 10 of the same characteristic size is a circular ring.

[0086] In this embodiment, the acoustic vias 10 in the gradient aperture array region 120 are distributed in a graded ring shape according to their characteristic aperture sizes. For the first closed ring 124 formed by connecting the centers of the characteristic apertures of the acoustic vias 10 with the same characteristic aperture, its shape has two options: a circular ring or a polygonal ring. Furthermore, when the first closed ring 124 is selected as a polygonal ring, its number of sides a is explicitly limited, requiring that the number of sides a satisfy N≥4. This means that the polygonal ring can be a quadrilateral ring, a pentagonal ring, a hexagonal ring, etc.

[0087] Preferably, the first closed ring 124 is circular in shape.

[0088] When the first closed ring 124 is in the form of a ring, due to the high symmetry of the ring, when the back electrode plate 1 is subjected to external forces such as diaphragm vibration during the operation of the MEMS chip, the stress can be uniformly distributed along the circumference of the ring. This uniform stress distribution avoids excessive stress concentration in local areas, effectively reducing the risk of structural damage to the back electrode plate 1 due to stress concentration, thereby enhancing the overall structural stability of the back electrode plate 1 and extending the service life of the MEMS chip. In addition, the symmetry of the ring makes the propagation characteristics of sound waves relatively consistent in different directions, reducing interference in the propagation process of sound waves and helping to improve the transmission efficiency and accuracy of acoustic signals.

[0089] According to an embodiment of this application, along the radial direction of the gradient aperture array region 120, the characteristic aperture difference ΔD of two adjacent acoustic through holes 10 satisfies: 0.2μm≤ΔD≤10μm.

[0090] In this embodiment, the characteristic aperture range of the acoustic through-hole 10 in the gradient aperture array region 120 is typically in the micrometer range. For example, the characteristic aperture range of the acoustic through-hole 10 is ≤30μm. Preferably, the characteristic aperture range of the acoustic through-hole 10 is 3μm-25μm, and further, 5μm-20μm. Typically, the characteristic aperture range of the acoustic through-hole 10 is 5μm-10μm.

[0091] In this embodiment, along the radial direction of the gradient aperture array region 120, two adjacent acoustic through-holes 10 have a specific difference in their characteristic apertures, that is, the characteristic aperture difference ΔD is limited to the range of 0.2μm to 10μm. Preferably, the characteristic aperture difference ΔD of two adjacent acoustic through-holes 10 is 1μm-8μm. Simultaneously, the characteristic apertures of the acoustic through-holes 10 throughout the entire gradient aperture array region 120 are at the micrometer scale, with a typical characteristic aperture range of ≤30μm. This design optimizes acoustic performance and structural characteristics by precisely controlling the aperture differences between adjacent acoustic through-holes 10 and the overall aperture range.

[0092] According to the embodiments of this application, refer to Figure 4 and Figure 6 The acoustic action area 12 also includes a main body area 121, in which the characteristic aperture size of all acoustic through holes 10 is constant, wherein the gradient aperture array area 120 is distributed in the peripheral area of ​​the main body area 121.

[0093] In this embodiment, the acoustic action area 12 also includes a main body area 121, that is, the acoustic action area 12 mainly includes the main body area 121 and the gradient aperture array area 120, which are two regions with different acoustic through-hole 10 characteristics.

[0094] The main area 121 is defined as a region that satisfies any of the following conditions: 1) Located at the geometric center of the back electrode plate 1; 2) Taking the geometric center of the back electrode plate 1 as the origin, the ratio of its coverage area S1 to the total area S0 of the opening area of ​​the back electrode plate 1 satisfies: .

[0095] When the main body region 121 satisfies condition 1) above, based on the characteristic aperture and geometry of the acoustic through-holes 10 (usually the acoustic through-holes 10 located at the geometric center of the back electrode plate 1), the characteristic aperture of each acoustic through-hole 10 in the main body region 121 continuously decreases along the direction from the center to the edge of the back electrode plate 1 (i.e., the gradient aperture array region 120). In this case, it is considered that the entire region in the acoustic action region 12 constitutes the gradient aperture array region 120.

[0096] Reference Figure 5 ,when Figure 5 Acoustic through-hole 10 in the edge transition region 14 according to Figure 6 When designing the edge transition region 14, it is assumed that all areas in the acoustic action region 12 constitute the gradient aperture array region 120.

[0097] In an optional embodiment, at least one acoustic through-hole 10 is formed within the main body region 121. A small portion of the acoustic function region 12 constitutes the main body region 121 (e.g., the offset distance Δr from the geometric center satisfies: 0 < Δr ≤ 0.2R, where R is the radius of the acoustic function region 12 of the back electrode plate 1), and the majority of the acoustic function region 12 constitutes the gradient aperture array region 120. In this case, it can also be considered that the entire region of the acoustic function region 12 constitutes the gradient aperture array region 120. When the main area 121 meets condition 2) above, refer to Figure 4 and Figure 6 Multiple acoustic through-holes 10 are formed within the main body region 121. A large portion of the acoustic function region 12 constitutes the main body region 121, while a small portion of the acoustic function region 12 constitutes the gradient aperture array region 120. Similarly, in this case, the geometry of the acoustic through-holes 10 in the gradient aperture array region 120 can be the same as or different from the geometry of the acoustic through-holes 10 in the main body region 121.

[0098] In this embodiment, the characteristic aperture size of all acoustic through-holes 10 within the main body region 121 remains constant. This means that the aperture size of the acoustic through-holes 10 is consistent within this region, providing a relatively stable and uniform channel environment for the propagation of sound waves. The gradient aperture array region 120 is distributed along the radial periphery of the main body region 121, and the characteristic apertures corresponding to the acoustic through-holes 10 in the gradient aperture array region 120 gradually decrease towards the edge (forming a transitional change in characteristic apertures from the inside to the outside). This arrangement allows the acoustic action region 12 to gradually transition from the constant aperture of the main body region 121 to the differentiated apertures in the gradient aperture array region 120.

[0099] Specifically, the acoustic through-holes 10 with constant apertures within the main body region 121 form a uniform structure. This uniformity ensures that the stress on the back electrode plate 1 is evenly distributed when subjected to external forces in the main body region 121, avoiding localized stress concentration. The gradient aperture array region 120 is distributed radially outward from the main body region 121, forming a transitional structure from the inside out. This transitional structure effectively disperses and transmits external forces. When external forces act on the gradient aperture array region 120, the stress is gradually dispersed along the direction of aperture change due to the gradual change in aperture, avoiding excessive stress in a single aperture region. In other words, the acoustic action region 12 formed by the gradient aperture array region 120 and the main body region 121 improves the back electrode plate 1's resistance to deformation by external forces and reduces stress concentration.

[0100] Furthermore, in terms of acoustic performance, the characteristic aperture size of all acoustic vias 10 within the main body region 121 is constant, providing a stable propagation channel for sound waves. This stability ensures that the propagation characteristics (such as propagation speed and attenuation) of sound waves are relatively consistent as they pass through the main body region 121, reducing acoustic interference and distortion caused by aperture changes. The gradually changing aperture array region 120 is distributed radially around the main body region 121, and its gradually changing aperture design achieves a smooth transition in acoustic performance. When sound waves enter the gradually changing aperture array region 120 from the main body region 121, the change in aperture guides a change in the propagation direction and energy distribution of the sound waves. This gradual change avoids strong reflection and scattering of sound waves at abrupt aperture changes, reducing acoustic energy loss.

[0101] According to the embodiments of this application, refer to Figure 7 Within the main body area 121, a second closed ring 125 is formed by enclosing the centers of the characteristic apertures of the acoustic through holes 10 arranged adjacent to each other along the circumference of the back electrode plate 1, with the geometric center of the back electrode plate 1 as the reference. Within the gradient aperture array region 120, in the acoustic through-holes 10 with the same characteristic aperture, the line connecting the centers of the characteristic apertures of all the acoustic through-holes 10 forms a first closed ring 124. The first closed ring 124 and the second closed ring 125 have the same shape, or have relatively parallel sides, or have different shapes.

[0102] In this embodiment, when the main body region 121 satisfies condition 2) above, the main body region 121 has a large area. With a large area, multiple acoustic through-holes 10 with the same characteristic aperture are uniformly arranged along the circumferential direction of the main body region 121. The centers of the characteristic apertures of these acoustic through-holes 10 uniformly arranged along the circumference of the back electrode plate 1 can form a second closed ring 125.

[0103] As described above, within the gradient aperture array region 120, among the acoustic through-holes 10 with the same characteristic aperture, the line connecting the centers of the characteristic apertures of all acoustic through-holes 10 can form a first closed ring 124. The shape of the first closed ring 124 can be a ring, a polygonal shape (e.g., a hexagonal shape), etc.

[0104] The fact that the first closed ring 124 and the second closed ring 125 have basically the same shape can be understood as: the first closed ring 124 and the second closed ring 125 have the same shape, or the two have relatively parallel sides.

[0105] For example, refer to Figure 4 The first closed ring 124 and the second closed ring 125 are both circular; or, refer to Figure 2a The first closed ring 124 is hexagonal in shape, and the second closed ring 125 is a regular hexagonal in shape; or, the first closed ring 124 is hexagonal in shape, and the second closed ring 125 is a circular ring.

[0106] Alternatively, the shapes of the first closed ring 124 and the second closed ring 125 may be completely different. For example, the first closed ring 124 may be a circular ring, while the second closed ring 125 may be a regular hexagonal ring. In this case, the shapes of the circular ring and the regular hexagonal ring can be compensated for by using a hexagonal ring-like structure.

[0107] In this embodiment, the centers of the plurality of acoustic through-holes 10 arranged circumferentially in the main body region 121 form a second closed ring 125. This structure provides uniform support and stress distribution for the main body region 121 of the back electrode plate 1. When the back electrode plate 1 is subjected to external forces (such as forces generated by diaphragm vibration), the second closed ring 125 structure can uniformly distribute stress within the ring region, avoiding local stress concentration. The first closed ring 124 formed by the centers of the acoustic through-holes 10 with the same characteristic aperture within the gradient aperture array region 120 also provides a stable structural framework for this region. Preferably, the first closed ring 124 and the second closed ring 125 can have substantially the same shape, which can form a synergistic acoustic effect and enhance the stability of specific acoustic performance.

[0108] According to some embodiments of this application, reference is made to Figure 7 The second closed ring 125 is one of a circular ring, a polygonal ring, or a polygonal ring-like ring. When the second closed ring 125 is a polygonal ring or a polygonal ring-like ring, the number of its sides N satisfies: N≥4.

[0109] In this embodiment, when the second closed ring 125 is designed as a circular ring, the acoustic through-holes 10 are evenly distributed around the center, allowing the sound waves to obtain a relatively symmetrical and uniform propagation environment during propagation. This symmetry ensures that the propagation characteristics of the sound waves are basically consistent in all directions, reducing acoustic interference and distortion caused by directional differences.

[0110] When the second closed ring 125 is a polygonal ring or a polygonal-like ring with N ≥ 4 sides, the sides and corners of the polygon or polygonal-like ring can affect sound waves. Polygons or polygonal-like rings with different numbers of sides have different acoustic characteristics and can be selected according to specific application requirements. For example, a hexagonal ring has high symmetry and can achieve a relatively uniform acoustic response in multiple directions. At the same time, its structure can selectively control sound waves of different frequencies, broaden the frequency response range of the acoustic action area 12, and improve acoustic performance.

[0111] According to a preferred embodiment of this application, referring to... Figure 7 The first closed ring 124 and the second closed ring 125 have different shapes. Specifically, the first closed ring 124 is a circular ring, and the second closed ring 125 is a polygonal ring. That is, in the main body region 121, the centers of the characteristic apertures of the acoustic through holes 10 uniformly distributed circumferentially along the main body region 121 form a polygonal ring (preferably a hexagonal ring). In the gradient aperture array region 120, the lines connecting the centers of the characteristic apertures of all acoustic through holes 10 with the same characteristic aperture form a circular ring.

[0112] In this embodiment, the first closed ring 124 is a circular ring. The circular ring has high symmetry and continuity. When the back electrode plate 1 is subjected to external force, the circular ring structure can evenly disperse the stress and avoid local stress concentration. The second closed ring 125 is hexagonal. The hexagonal ring forms a stable geometric structure with six sides, making the force distribution in all directions more uniform. For example, the alternating force generated by diaphragm vibration or external impact force can evenly disperse the stress and avoid local stress concentration.

[0113] Furthermore, in terms of acoustic performance, in the gradient aperture array region 120, a ring is formed by connecting the centers of acoustic through-holes 10 with the same characteristic aperture. This design allows the sound waves to obtain a relatively uniform and symmetrical acoustic environment during propagation. The symmetry of the ring ensures that the propagation characteristics of the sound waves are basically consistent in different directions, reducing acoustic interference and distortion caused by directional differences. In the main body region 121, the hexagonal ring has high symmetry, enabling a relatively uniform acoustic response in multiple directions and enhancing the acoustic effect.

[0114] Furthermore, when the acoustic through holes 10 uniformly distributed around the circumference of the main body region 121 form a hexagonal structure with the center of their characteristic apertures, it is preferable to design the geometry of the acoustic through holes 10 in the main body region 121 as hexagonal.

[0115] Compared to the case where the acoustic vias 10 within the main body region 121 are circular in geometry, when the acoustic vias 10 within the main body region 121 adopt a hexagonal geometry, the arrangement of adjacent acoustic vias 10 is more compact, specifically manifested in a significant reduction in the spacing between adjacent acoustic vias 10. This compact arrangement helps to further optimize the acoustic performance of the MEMS chip applied to MEMS systems. For example, the regularity and compactness of the hexagonal arrangement make the propagation characteristics of sound waves more consistent in all directions, enabling a more uniform distribution of the sound field throughout the entire back electrode plate 1's operating area, providing a more stable and reliable acoustic environment for acoustic devices.

[0116] According to further embodiments of this application, refer to Figure 6 and Figure 7 When the first closed ring 124 is a circular ring and the second closed ring 125 is a polygonal ring, a transition region 13 is formed between the first closed ring 124 and the second closed ring 125. A first set of transition holes 131 is provided in the transition zone 13 near the second closed annular region 125, and the first set of transition holes 131 are randomly distributed along the circumferential direction of the transition zone 13; and, A second set of transition holes 132 is provided in the transition zone 13 near the first closed ring 124 region. The second set of transition holes 132 are evenly distributed in a ring along the circumferential direction of the transition zone 13.

[0117] In this embodiment, a differentiated design is adopted in the layout of the transition region 13. A first set of transition holes 131 is formed in the region near the second closed ring 125 (polygonal ring), and these holes are randomly distributed along the circumferential direction of the transition region 13. In the region of the transition region 13 near the first closed ring 124 (circular ring), a second set of transition holes 132 is formed, and this set of holes is evenly distributed in a circular pattern along the circumferential direction of the transition region 13.

[0118] Specifically, since there are significant differences in shape and structural characteristics between the circular ring and the hexagonal ring, these differences can adversely affect the acoustic performance and structural stability of the back electrode plate 1. To solve this problem, a transition region 13 is provided between the first closed ring 124 and the second closed ring 125, and a first set of transition holes 131 and a second set of transition holes 132 are respectively provided in the transition region 13.

[0119] The first set of transition holes 131 are randomly distributed, with each hole filling the outermost region of the main body region 121. This filling method, combined with the outermost acoustic through-holes 10 of the main body region 121, makes the shape formed by the characteristic apertures of the outermost acoustic through-holes 10 more closely resemble a ring. The second set of transition holes 132 are evenly distributed in a ring along the circumferential direction of the transition region 13, echoing the first closed ring 124 (ring), further enhancing the consistency of the structure and acoustic properties between the transition region 13 and the ring region.

[0120] In one specific embodiment, refer to Figure 7 In the first group of transition holes 131, each transition hole has a different aperture, and the aperture of each transition hole is smaller than the minimum characteristic aperture of the acoustic through hole 10 in the gradient aperture array region 120; in the second group of transition holes 132, each transition hole has the same aperture and is smaller than the minimum characteristic aperture of the acoustic through hole 10 in the gradient aperture array region 120.

[0121] In other words, in the first group of transition holes 131, the diameters of the randomly distributed transition holes are different. Transition holes with different diameters can disperse stress in different ways, avoiding stress concentration in local areas.

[0122] According to the embodiments of this application, refer to Figure 4 The main body region 121 and the gradient aperture array region 120 are arranged adjacent to each other, and at least one first acoustic through hole 101 is provided on the side of the main body region 121 near the gradient aperture array region 120. The gradient aperture array region 120 is provided with at least one second acoustic through-hole 102 on the side near the main body region 121, wherein the characteristic aperture size of the second acoustic through-hole 102 is less than or equal to the characteristic aperture size of the first acoustic through-hole 101. In this embodiment, the main body region 121 and the gradient aperture array region 120 are arranged adjacent to each other. That is, in the specific structure of the back electrode plate 1, one side of the gradient aperture array region 120 is the main body region 121, and the other side of the gradient aperture array region 120 can be the edge transition region 14. A fixed support region 11 is provided around the edge transition region 14. In the edge transition region 14, a plurality of closely arranged acoustic through holes 10 (the size of which is smaller than the minimum characteristic aperture of the acoustic through holes 10 in the acoustic action region 12) are provided. The acoustic through holes 10 are used to allow the etching solution to pass through in order to etch the insulating layer located below the back electrode plate 1.

[0123] In this embodiment, the main body region 121 and the gradient aperture array region 120 are arranged adjacently and transitioned through a first acoustic through-hole 101 and a second acoustic through-hole 102. This structural layout allows the stress on the back electrode plate 1 to be distributed more evenly between the two regions when under stress. The smaller aperture size of the second acoustic through-hole 102 can limit stress concentration to a certain extent, avoiding structural damage caused by excessive local stress. At the same time, the synergistic effect of the first acoustic through-hole 101 and the second acoustic through-hole 102 improves the stability of the entire back electrode plate 1 structure. Furthermore, the gradient aperture design from the main body region 121 to the gradient aperture array region 120 achieves a smooth transition of the structure between the two regions. This smooth transition avoids stress concentration and abrupt changes in acoustic performance caused by structural abruptness.

[0124] According to the embodiments of this application, refer to Figure 6 and Figure 7 The gradient aperture array region 120 includes a first sub-array region 122 and a second sub-array region 123, wherein the first sub-array region 122 is disposed close to the main body region 121 relative to the second sub-array region 123. In the first sub-array region 122, a first closed ring 124 formed by connecting the centers of the characteristic apertures of acoustic through-holes 10 with the same characteristic aperture has relatively parallel sides to a second closed ring 125 formed within the main body region 121, which is formed by surrounding the centers of the characteristic apertures of the acoustic through-holes 10 arranged circumferentially adjacent to the back electrode plate 1 with reference to the geometric center of the back electrode plate 1; and In the second sub-array region 123, the first closed ring 124 formed by connecting the centers of the characteristic apertures of the acoustic through holes 10 with the same characteristic aperture is different from the shape of the second closed ring 125 formed in the main body region 121 by enclosing the centers of the characteristic apertures of the acoustic through holes 10 arranged adjacent to each other along the circumference of the back electrode plate 1 with the geometric center of the back electrode plate 1 as the reference.

[0125] In this embodiment, the gradient aperture array region 120 is divided into a first sub-array region 122 and a second sub-array region 123, wherein the first sub-array region 122 is positioned closer to the main body region 121 than the second sub-array region 123.

[0126] Within the first sub-array region 122, acoustic vias 10 with the same characteristic aperture can form a first closed ring 124 structure by connecting the centers of their characteristic apertures. The shape of this first closed ring 124 is substantially consistent with the shape of the second closed ring 125 formed by the centers of the acoustic vias 10 arranged circumferentially adjacent to each other within the main region 121. This design effectively avoids stress concentration problems caused by the different shapes of the two closed rings, further improving acoustic performance.

[0127] In the specific implementation of this example, within the first subarray region 122, the first closed ring 124 is shaped like a hexagonal ring, and the second closed ring 125 is a hexagonal ring.

[0128] In the second sub-array region 123, for acoustic through-holes 10 with the same characteristic aperture, the first closed ring structure 124, formed by connecting the centers of their characteristic apertures sequentially, and the second closed ring structure 125, formed by the centers of the acoustic through-holes 10 arranged circumferentially adjacent to each other in the main region 121, differ in shape. Specifically, in the second sub-array region 123, the first closed ring structure 124 is a circular ring, and the second closed ring structure 125 is a hexagonal ring.

[0129] In this embodiment, the first sub-array region 122 serves as a transition compensation region between the main body region 121 and the second sub-array region 123. The shape of the first closed ring 124 in the first sub-array region 122 compensates for the difference in the arrangement shape of each acoustic through hole 10 in the main body region 121 and the second sub-array region 123, so as to avoid stress concentration.

[0130] According to further embodiments of this application, refer to Figure 6 and Figure 7 A transition region 13 is formed between the first subarray region 122 and the second subarray region 123. A first set of transition holes 131 are formed in the area of ​​the transition region 13 near the first subarray region 122. The first set of transition holes 131 are randomly distributed along the circumferential direction of the transition region 13. A second set of transition holes 132 is provided in the area of ​​the transition region 13 near the second sub-array region 123. The second set of transition holes 132 are evenly distributed in a ring along the circumferential direction of the transition region 13.

[0131] In this embodiment, to further compensate for the shape difference between the circular ring and the polygonal ring, a transition region 13 is formed between the first sub-array region 122 and the second sub-array region 123. The function of the transition region 13 formed between the first sub-array region 122 and the second sub-array region 123 is the same as that of the transition region 13 formed between the main body region 121 and the gradient aperture array region 120 when the shapes of the second closed ring 125 formed in the main body region 121 and the first closed ring 124 formed in the gradient aperture array region 120 are different, as mentioned above, and will not be repeated here.

[0132] Furthermore, an edge transition region 14 is provided on the outer periphery of the second sub-array region 123, and a fixed support region 11 is provided around the edge transition region 14. In the edge transition region 14, a plurality of closely arranged acoustic through holes 10 (the size of which is smaller than the minimum characteristic aperture of the acoustic through holes 10 in the acoustic action region 12) are provided. These acoustic through holes 10 are used to allow etching fluid to pass through in order to etch the insulating layer located below the back electrode plate 1.

[0133] According to an embodiment of this application, in the second sub-array region 123, the maximum characteristic aperture of the acoustic through-hole 10 is smaller than that in the first sub-array region 122, where the minimum characteristic aperture of the acoustic through-hole 10 is smaller.

[0134] In this embodiment, the difference in aperture size of the acoustic vias 10 between the second subarray region 123 and the first subarray region 122 helps to achieve a uniform distribution of stress within the back electrode plate 1. When sound waves act on the back electrode plate 1, the acoustic vias 10 of different sizes will cause different transmission and dispersion effects of stress in different regions.

[0135] Specifically, the smaller acoustic through-holes 10 in the second sub-array region 123 can withstand larger local stresses and distribute them evenly to the surrounding area. The larger acoustic through-holes 10 in the first sub-array region 122 help reduce stress concentration, allowing the entire back electrode plate 1 to distribute stress more evenly when under load, thereby improving the structural strength and stability of the back electrode plate 1 and reducing the risk of structural damage caused by stress concentration.

[0136] According to the embodiments of this application, the apertures of each transition hole included in the first group of transition holes 131 are different, and the aperture of each transition hole is smaller than the minimum characteristic aperture of the acoustic through hole 10 in the gradient aperture array region 120. The transition holes included in the second group of transition holes 132 have the same diameter and are smaller than the minimum characteristic diameter of the acoustic through hole 10 in the gradient aperture array region 120.

[0137] In this embodiment, the design of different apertures in the first set of transition holes 131 and the uniform acoustic through-hole diameter setting in the second set of transition holes 132 help to disperse the stress generated in the back electrode plate 1 when subjected to force. When sound waves or other external forces act on the back electrode plate 1, the transition holes with different apertures can disperse the stress in different ways, avoiding stress concentration in local areas. Smaller transition hole diameters can withstand greater local stress and evenly transfer it to the surrounding structure, enhancing the overall structural strength of the back electrode plate 1.

[0138] According to a second aspect of this application, a MEMS system is provided. The MEMS system includes the MEMS chip described above. Exemplarily, the MEMS system can be a MEMS microphone, a pressure sensor, or other acoustic transducer. The MEMS microphone can be a single-diaphragm microphone, a dual-diaphragm microphone, or a dual-backplate microphone.

[0139] According to a third aspect of this application, an electronic device is provided. The electronic device includes the MEMS system described above. Exemplarily, the electronic device may be a mobile phone, computer, smart wearable device (e.g., headphones, watch, etc.), etc.

[0140] The above embodiments mainly describe the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. For the sake of brevity, they will not be elaborated here.

[0141] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. A MEMS chip, characterized by, The back plate (1) has: A fixed support area (11) for fixed connection with a support structure; An acoustic action area (12) arranged opposite to the diaphragm to form an acoustic capacitor structure; Wherein, the acoustic action area (12) is provided with acoustic through holes (10), and at least part of the acoustic through holes (10) constitute a gradually changing aperture array area (120); in the gradually changing aperture array area (120), the characteristic apertures of the acoustic through holes (10) are continuously and decreasingly distributed along the radial direction of the gradually changing aperture array area (120) towards the edge direction; The characteristic aperture is defined as the diameter of the smallest circumscribed circle determined based on the geometric shape of the acoustic through hole (10). In the gradually changing aperture array area (120), the geometric shapes of all acoustic through holes (10) are the same, or in the gradually changing aperture array area (120), the geometric shapes of acoustic through holes (10) with the same characteristic aperture are the same.

2. The MEMS chip of claim 1, wherein, In the gradually changing aperture array area (120), the acoustic through holes (10) are distributed in a hierarchical ring shape according to the characteristic aperture size; 3. The MEMS chip according to claim 1 or 2, characterized in that, The hierarchical ring shape specifically satisfies: in the acoustic through holes (10) with the same characteristic aperture, the connecting line of the centers of the characteristic apertures of all acoustic through holes (10) constitutes a first closed ring (124), and the number n of the first closed ring (124) satisfies: n≥3. The first closed ring (124) is a circular ring or a polygonal ring; when the first closed ring (124) is a polygonal ring, the number N of its edges satisfies: N≥4.

4. The MEMS chip of claim 3, wherein, Along the radial direction of the gradually changing aperture array area (120), the characteristic aperture difference ΔD of two adjacent acoustic through holes (10) satisfies: 0.2μm≤ΔD≤10μm.

5. The MEMS chip of claim 1, wherein, The acoustic action area (12) includes a main body area (121), and in the main body area (121), the characteristic aperture size of all acoustic through holes (10) is constant, wherein the gradually changing aperture array area (120) is distributed in the peripheral area of the main body area (121).

6. The MEMS chip of claim 1, wherein, In the main body area (121), taking the geometric center of the back plate (1) as the reference, the centers of the characteristic apertures of the acoustic through holes (10) arranged adjacent to each other along the circumference of the back plate (1) form a second closed ring (125); 7. The MEMS chip of claim 6, wherein, In the gradually changing aperture array area (120), in the acoustic through holes (10) with the same characteristic aperture, the connecting line of the centers of the characteristic apertures of all acoustic through holes (10) constitutes a first closed ring (124); The first closed ring (124) and the second closed ring (125) are the same in shape, or have relatively parallel edges, or are different in shape. The second closed ring (125) is one of a circular ring, a polygonal ring, or a polygonal ring; when the second closed ring (125) is a polygonal ring or a polygonal ring, the number N of its edges satisfies: N≥4.

8. The MEMS chip of claim 7, wherein, ​ 9. The MEMS chip of claim 8, wherein, In the case that the first closed loop (124) and the second closed loop (125) are not the same, the first closed loop (124) is a circular ring, and the second closed loop (125) is a polygonal ring.

10. The MEMS chip of claim 9, wherein, In the case that the first closed loop (124) is a circular ring and the second closed loop (125) is a polygonal ring, a transition zone (13) is formed between the first closed loop (124) and the second closed loop (125). A first group of transition holes (131) is arranged in the transition zone (13) near the second closed loop (125), and the first group of transition holes (131) are randomly distributed along the circumferential direction of the transition zone (13); and A second group of transition holes (132) is arranged in the transition zone (13) near the first closed loop (124), and the second group of transition holes (132) are uniformly distributed in a circular ring along the circumferential direction of the transition zone (13).

11. The MEMS chip of claim 6, wherein, The main body zone (121) is defined as a zone satisfying any one of the following conditions: Located at the geometric center of the back plate (1); The ratio of the covering area S1 of the back plate (1) to the total area S0 of the back plate (1) opening region satisfies: .

12. The MEMS chip of claim 6, wherein, The main body zone (121) and the gradually changing aperture array zone (120) are arranged adjacent to each other, and at least one first acoustic through hole (101) is arranged on the side of the main body zone (121) close to the gradually changing aperture array zone (120); At least one second acoustic through hole (102) is arranged on the side of the gradually changing aperture array zone (120) close to the main body zone (121), wherein the characteristic aperture size of the second acoustic through hole (102) is less than or equal to the characteristic aperture size of the first acoustic through hole (101).

13. The MEMS chip of claim 6, wherein, The gradually changing aperture array zone (120) includes a first sub-array zone (122) and a second sub-array zone (123), and the first sub-array zone (122) is arranged close to the main body zone (121) relative to the second sub-array zone (123); In the first sub-array zone (122), the first closed loop (124) formed by the connecting lines of the centers of the characteristic apertures of the acoustic through holes (10) with the same characteristic aperture is relatively parallel to the second closed loop (125) formed by the centers of the characteristic apertures of the acoustic through holes (10) arranged adjacent to each other along the circumferential direction of the back plate (1) in the main body zone (121) and with the geometric center of the back plate (1) as the reference; and In the second sub-array zone (123), the first closed loop (124) formed by the connecting lines of the centers of the characteristic apertures of the acoustic through holes (10) with the same characteristic aperture is not the same as the shape of the second closed loop (125) formed by the centers of the characteristic apertures of the acoustic through holes (10) arranged adjacent to each other along the circumferential direction of the back plate (1) in the main body zone (121) and with the geometric center of the back plate (1) as the reference.

14. The MEMS chip of claim 13, wherein, A transition region (13) is formed between the first sub-array region (122) and the second sub-array region (123), a first group of transition holes (131) is formed in a region of the transition region (13) close to the first sub-array region (122), and the first group of transition holes (131) is randomly distributed along the circumferential direction of the transition region (13); and A second group of transition holes (132) is formed in a region of the transition region (13) close to the second sub-array region (123), and the second group of transition holes (132) is uniformly distributed in a circular ring along the circumferential direction of the transition region (13).

15. The MEMS chip of claim 14, wherein, In the second sub-array region (123), the maximum characteristic aperture of the acoustic via (10) is less than In the first sub-array region (122), the minimum characteristic aperture of the acoustic via (10) is 16. The MEMS chip of claim 15 or 10, wherein, The apertures of the transition holes in the first group of transition holes (131) are different, and the apertures of the transition holes are less than the minimum characteristic aperture of the acoustic via (10) in the gradually-varying-aperture array region (120); The apertures of the transition holes in the second group of transition holes (132) are the same and are less than the minimum characteristic aperture of the acoustic via (10) in the gradually-varying-aperture array region (120).

17. A MEMS system, characterized by The MEMS system comprises the MEMS chip according to any one of claims 1-16.

18. An electronic device, comprising: The electronic device comprises the MEMS system according to claim 17.

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