A MEMS sensor and electronic device

Abstract

The application relates to a MEMS sensor and an electronic device, wherein the MEMS sensor comprises a substrate provided with a back cavity and a first detection unit. The first detection unit comprises a first insulating film, a first electrode layer, a second insulating film and a first support column which are sequentially stacked. The first electrode layer is provided with first hollow grooves at intervals; the first support column passes through the corresponding first hollow grooves, and the two ends of the first support column are connected with the insulating films on the two sides of the first electrode layer; wherein the two ends of each first support column are provided with a first electrode part, and the side wall of the first electrode part and the inner wall of the corresponding first hollow groove have a spacing, and together constitute a detection capacitor. The application decouples mechanical sensitivity and electrical sensitivity, opens a plurality of first hollow grooves in the first electrode layer, forms a detection capacitor array in parallel / differential output with the corresponding first support column, suppresses high-order distortion under large deflection and complex load, and realizes high sensitivity, high linearity and long-term reliability in a wide dynamic range.

Description

Technical Field

[0001] This application relates to the field of microelectromechanical systems, and more particularly to a MEMS sensor and electronic device. Background Technology

[0002] Traditional capacitive MEMS sensors consist of a movable diaphragm and a fixed back electrode, arranged parallel to each other. A DC bias voltage is applied between the diaphragm and the back electrode, forming a parallel-plate capacitor that changes with the deformation of the diaphragm. When external pressure is applied to the diaphragm, the diaphragm deforms, changing the distance between the two electrodes, which in turn causes a change in the capacitance value. Pressure measurement can be achieved by detecting the capacitance response.

[0003] However, it is difficult to simultaneously achieve both electrical and mechanical sensitivity in traditional MEMS sensors. Specifically, improving electrical sensitivity is usually achieved by reducing electrode spacing, increasing diaphragm radius, or reducing membrane stress. However, these methods make the diaphragm more prone to instability or bottoming out under large amplitude conditions, leading to measurement errors and introducing higher-order nonlinear distortions. To suppress instability, it is usually necessary to increase the initial tension stress of the diaphragm, but this increases the diaphragm stiffness and weakens its mechanical sensitivity. At the same time, when the diaphragm deflection enters the large deformation region or is subjected to complex loads such as non-uniformity or impact, the strain distribution between the central and edge regions of traditional MEMS sensors becomes significantly unbalanced. The capacitive response is prone to higher-order nonlinear distortions, significantly reducing measurement linearity and affecting the accuracy and long-term reliability of the sensor. Summary of the Invention

[0004] This application provides a MEMS sensor and electronic device, which aims to improve the accuracy and reliability of MEMS sensors.

[0005] To achieve the above objectives, according to a first aspect of this application, a MEMS sensor is provided, comprising:

[0006] The base has a back cavity on one side surface;

[0007] The first detection unit includes:

[0008] The first insulating film is located on the side surface of the substrate where the back cavity is formed;

[0009] The first electrode layer is located on the side of the first insulating film facing away from the substrate, and is disposed opposite to the first insulating film and is spaced apart; a plurality of first hollow grooves are spaced apart on the first electrode layer;

[0010] The second insulating film is located on the side of the first electrode layer facing away from the first insulating film, and is disposed opposite to the first electrode layer and has a gap;

[0011] Multiple first support columns, each first support column passing through a corresponding first hollow slot, and both ends connected to the first insulating film and the second insulating film respectively;

[0012] In this embodiment, a first electrode portion is provided between the two ends of each of the first support columns, and there is a gap between the side wall of the first electrode portion and the inner wall of the corresponding first hollow groove, which together constitute a detection capacitor; when the first insulating film and / or the second insulating film vibrate to drive the first support column to move in the thickness direction of the substrate, the projection of the first electrode portion and the projection of the first electrode layer at least partially overlap in a direction parallel to the surface of the substrate.

[0013] Optionally, the first electrode portion is designed to mimic the shape of the first hollowed-out groove.

[0014] Optionally, the first hollow groove includes a circular hole groove, a cross-shaped groove, or a spiral groove.

[0015] Optionally, the first electrode layer includes a plurality of annular distribution areas that are concentrically arranged and radially spaced based on the structural center of the first electrode layer;

[0016] Within each of the circular distribution areas, the first hollowed-out grooves are distributed at intervals along the circumference of the circular distribution area, and the first support column is located at the structural center corresponding to the first hollowed-out groove.

[0017] Optionally, the first electrode layer further includes a central expansion groove concentrically disposed with the structural center of the first electrode layer. The central expansion groove includes a first through groove extending radially along the annular distribution area. Each of the first through grooves is distributed circumferentially along the annular distribution area and is interconnected with each other.

[0018] The first support column in the central expansion groove is located at the structural center of the first electrode layer, and the first electrode part connected to the first support column is designed to mimic the shape of the central expansion groove.

[0019] Optionally, the central expansion slot further includes a second through slot, which is connected to the first through slot. The second through slot extends circumferentially along the annular distribution area and is distributed at intervals along the circumferential direction.

[0020] Optionally, the first electrode layer includes a first distribution area concentrically disposed with the structural center of the first electrode layer, and the projection of the first distribution area in the thickness direction of the substrate is circular;

[0021] Each of the first hollowed-out grooves is distributed circumferentially along the first distribution area, and each of the first hollowed-out grooves includes a first groove extending radially and at least one second groove extending circumferentially. The first groove and the second groove are connected, and the first support column in each of the first hollowed-out grooves is located at the intersection of the second groove and the first groove.

[0022] Optionally, both the first insulating film and the second insulating film include a first film layer, a second film layer and a third film layer disposed sequentially along the thickness direction of the substrate, wherein the first film layer and the third film layer are positive stress layers and the second film layer is a negative stress layer.

[0023] Optionally, the first support column includes a first conductive segment and a first insulating segment connected to each other, and the first electrode portion is connected between the first conductive segment and the first insulating segment;

[0024] The first conductive segment is connected to one of the first insulating film and the second insulating film, and the first insulating segment is connected to the other of the first insulating film and the second insulating film. An electrical connection line is laid on the insulating film connected to the first conductive segment, and the first conductive segment is connected to the electrical connection line.

[0025] Optionally, the two ends of the first support column are respectively second conductive segments, and a second insulating segment is connected between the two second conductive segments. A first electrode portion is connected between each second conductive segment and the second insulating segment. Electrical connection lines are laid on both the first insulating film and the second insulating film, and each second conductive segment is connected to the electrical connection line on the corresponding insulating film.

[0026] In this configuration, on the same first support column, the sidewalls of the two first electrode portions respectively form detection capacitors with the sidewalls of the corresponding first hollow slots, and the two detection capacitors constitute a set of differential capacitors.

[0027] Optionally, it further includes: at least one second detection unit located on the side of the first detection unit away from the substrate;

[0028] The second detection unit includes:

[0029] The second electrode layer has multiple second hollow slots spaced apart on it.

[0030] The third insulating film is located on the side surface of the second electrode layer opposite to the second insulating film, and is disposed opposite to the second electrode layer and has a gap;

[0031] The second support column passes through the second hollow groove of the corresponding second electrode layer, and the two ends of the second support column are respectively connected to the insulating film on both sides of the second electrode layer; a second electrode part is provided between the two ends of each second support column, and there is a gap between the side wall of the second electrode part and the inner wall of the corresponding second hollow groove, which together constitute the second detection capacitor.

[0032] Optionally, when there is only one second detection unit,

[0033] The second electrode layer is located between the third insulating film and the second insulating film; within the second detection unit, a second support column connected to the second insulating film passes through the second insulating film and connects to the first support column in the first detection unit;

[0034] When there are multiple second detection units

[0035] In at least one of the two adjacent second detection units, the second electrode layer is located between the two third insulating films. Within this second detection unit, a second support column connected to the third insulating film passes through the third insulating film and connects to a second support column in the other second detection unit.

[0036] Optionally, the ends of the support columns on both sides of the insulating film between two adjacent detection units are electrically connected to the same electrical connection line, which is located on one side surface of the insulating film.

[0037] Optionally, a first support layer is provided between the first insulating film and the substrate, and a first cavity is formed through the first support layer; a second support layer is provided between the first insulating film and the first electrode layer, and a second cavity is formed through the second support layer; a third support layer is provided between the second insulating film and the first electrode layer, and a third cavity is formed through the third support layer.

[0038] In the thickness direction of the substrate, the projections of the first chamber, the second chamber, the third chamber, and the back cavity overlap.

[0039] According to a second aspect of this application, an electronic device is provided, comprising any of the MEMS sensors disclosed above.

[0040] In the MEMS sensor of this application embodiment, the pressure (or force) change acting on the MEMS sensor by external forces is directly sensed through the vibration of the first insulating film and / or the second insulating film. The first and second insulating films flex synchronously or alternately, converting the force signal into the displacement of the first support column in the thickness direction of the substrate, causing a change in the overlap area between the first electrode portion and the first electrode layer on the first support column, thereby generating a measurable capacitance change. In this application embodiment, the mechanical sensitivity is determined by the first and second insulating films, and the electrical sensitivity is determined by the overlap area between the first electrode layer and the first electrode portion. The two are decoupled, and the electrical sensitivity can be flexibly adjusted by adjusting the overlap area of ​​the first electrode portion and the first electrode layer without sacrificing the mechanical sensitivity. At the same time, this application has multiple first hollow slots on the first electrode layer, each slot corresponding to a first support column, and the first support column is connected to the upper and lower diaphragms at both ends. The first electrode on each first support column and the inner wall of the first hollowed-out groove together form a detection capacitor. The output of multiple detection capacitors in parallel (or differentially configured) is equivalent to "discrete small deformation series superposition". This can effectively average the nonlinear response of the central area and the edge area caused by boundary constraints or local wrinkles, making the overall capacitance change tend to be linear. It effectively suppresses high-order nonlinear distortion under large deflection and complex load, thus achieving high sensitivity, high linearity and good reliability in a wide dynamic range.

[0041] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments 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 these drawings without creative effort.

[0043] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0044] Figure 1 This is a schematic diagram of the structure of a MEMS sensor disclosed in an embodiment of this application. Figure 1 ;

[0045] Figure 2 This is a top view of an electrode layer disclosed in an embodiment of this application. Figure 1 ;

[0046] Figure 3 This is a top view of an electrode layer disclosed in an embodiment of this application. Figure 2 ;

[0047] Figure 4 This is a top view of an electrode layer disclosed in an embodiment of this application. Figure 3 ;

[0048] Figure 5 This is a top view of an electrode layer disclosed in an embodiment of this application. Figure 4 ;

[0049] Figure 6 This is a top view of an electrode layer disclosed in an embodiment of this application. Figure 5 ;

[0050] Figure 7 This is a top view of an electrode layer disclosed in an embodiment of this application. Figure 6 ;

[0051] Figure 8 This is a top view of an electrode layer disclosed in an embodiment of this application. Figure 7 ;

[0052] Figure 9 This is a schematic diagram of the structure of a MEMS sensor disclosed in an embodiment of this application. Figure 2 ;

[0053] Figure 10 This is a schematic diagram of the structure of a MEMS sensor disclosed in an embodiment of this application. Figure 3 ;

[0054] Figure 11 This is a schematic diagram of the structure of a MEMS sensor disclosed in an embodiment of this application. Figure 4 .

[0055] Explanation of reference numerals in the attached figures:

[0056] 1. Base; 11. Dorsal cavity;

[0057] 2. First detection unit;

[0058] 21. First insulating film; 211. First film layer; 212. Second film layer; 213. Third film layer;

[0059] 22. First electrode layer; 221. First hollowed-out groove; 2211. First groove; 2212. Second groove; 222. Circular distribution area; 223. Central expansion groove; 2231. First through groove; 2232. Second through groove; 224. First distribution area;

[0060] 23. Second insulating film;

[0061] 24. First support column; 241. First conductive segment; 242. First insulating segment; 243. Second conductive segment; 244. Second insulating segment;

[0062] 25. First electrode section;

[0063] 26. First support layer; 261. First chamber;

[0064] 27. Second support layer; 271. Second chamber;

[0065] 28. Third support layer; 281. Third chamber;

[0066] 29. Electrical connection wires;

[0067] 3. Second detection unit; 31. Second electrode layer; 311. Second hollow groove; 32. Third insulating film; 33. Second support column; 34. Second electrode part. Detailed Implementation

[0068] 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 them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0069] As described in the background section, a traditional capacitive MEMS sensor consists of a movable diaphragm and a fixed back electrode, arranged parallel to each other. A DC bias voltage is applied between the diaphragm and the back electrode, forming a parallel-plate capacitor that changes with the deformation of the diaphragm. When external pressure is applied to the diaphragm, the diaphragm deforms, changing the distance between the two electrodes, which in turn causes a change in the capacitance value. Pressure measurement can be achieved by detecting the capacitance response.

[0070] However, it is difficult to simultaneously achieve both electrical and mechanical sensitivity in traditional MEMS sensors. Specifically, improving electrical sensitivity is usually achieved by reducing electrode spacing, increasing diaphragm radius, or reducing membrane stress. However, these methods make the diaphragm more prone to instability or bottoming out under large amplitude conditions, leading to measurement errors and introducing higher-order nonlinear distortions. To suppress instability, it is usually necessary to increase the initial tension stress of the diaphragm, but this increases the diaphragm stiffness and weakens its mechanical sensitivity. At the same time, when the diaphragm deflection enters the large deformation region or is subjected to complex loads such as non-uniformity or impact, the strain distribution between the central and edge regions of traditional MEMS sensors becomes significantly unbalanced. The capacitive response is prone to higher-order nonlinear distortions, significantly reducing measurement linearity and affecting the accuracy and long-term reliability of the sensor.

[0071] Specifically, in traditional planar capacitive MEMS sensors, the electrical sensitivity (i.e., the capacitance change dC / dz per unit displacement) and the mechanical sensitivity (i.e., the displacement dw / dP per unit pressure) are each affected by design parameters (especially the initial electrode gap). The mutual constraint between the diaphragm stiffness (k) and the diaphragm stiffness (k) is specifically manifested as follows:

[0072] In traditional planar capacitive MEMS sensors, improving mechanical sensitivity requires reducing the stiffness of the diaphragm, making it more susceptible to deformation. However, this necessitates a larger initial gap to prevent excessive diaphragm deflection or "bottoming out" under medium to high voltage conditions. The electrical sensitivity of traditional planar capacitive MEMS sensors is... Larger initial electrode gap This will significantly reduce the electrical sensitivity, making it difficult for MEMS sensors to distinguish minute deflection changes, resulting in insufficient electrical sensitivity of MEMS sensors.

[0073] Furthermore, in traditional planar capacitive MEMS sensors, the initial electrode gap is typically increased to prevent the diaphragm from bottoming out or becoming unstable. Alternatively, the diaphragm stiffness k could be increased. However, increasing the initial electrode gap... Increasing the diaphragm stiffness (k) will sacrifice electrical sensitivity and increase mechanical sensitivity, causing MEMS sensors to have insufficient capacitive or displacement response, making it difficult to maintain high accuracy throughout the entire dynamic range.

[0074] Therefore, in order to balance the electrical and mechanical sensitivity of the MEMS sensor and improve the measurement linearity, thereby enhancing the accuracy and reliability of the MEMS sensor throughout the dynamic measurement range, this application discloses a MEMS sensor.

[0075] Reference Figure 1The MEMS sensor disclosed in this application includes a substrate 1 and a first detection unit 2. A back cavity 11 is formed on one side surface of the substrate 1. The first detection unit 2 includes a first insulating film 21, a first electrode layer 22, a second insulating film 23, and a plurality of first support pillars 24. The first insulating film 21 is located on the side surface of the substrate 1 where the back cavity 11 is formed. The first electrode layer 22 is located on the side surface of the first insulating film 21 facing away from the substrate 1, and the first electrode layer 22 is disposed opposite to the first insulating film 21 and is spaced apart. A plurality of first hollow grooves 221 are spaced apart on the first electrode layer 22. The second insulating film 23 is located on the side surface of the first electrode layer 22 facing away from the first insulating film 21, and is disposed opposite to the first electrode layer 22 and is spaced apart. Multiple first support pillars 24 correspond one-to-one with multiple first hollow slots 221. The first support pillars 24 pass through the corresponding first hollow slots 221, and their two ends are connected to the first insulating film 21 and the second insulating film 23, respectively. A first electrode portion 25 is provided between the two ends of each first support pillar 24. The sidewall of the first electrode portion 25 has a gap with the inner wall of the corresponding first hollow slot 221, and together they form a detection capacitor. When the first insulating film 21 and / or the second insulating film 23 vibrate to drive the first support pillar 24 to move in the thickness direction of the substrate 1, the projection of the first electrode portion 25 at least partially overlaps with the projection of the first electrode layer 22 in a direction parallel to the surface of the substrate 1.

[0076] In the embodiments of the application, the pressure (or force) changes acting on the MEMS sensor are directly sensed by the vibration of the first insulating film 21 and / or the second insulating film 23. The first insulating film 21 and the second insulating film 23 flex synchronously or alternately, converting the force signal into the displacement of the first support column 24 in the thickness direction of the substrate 1, causing a change in the overlap area between the first electrode portion 25 and the first electrode layer 22 on the first support column 24, thereby generating a measurable capacitance change. In this embodiment of the application, the mechanical sensitivity is determined by the first insulating film 21 and the second insulating film 23, and the electrical sensitivity is determined by the overlap area between the first electrode layer 22 and the first electrode portion 25. The two are decoupled, and the electrical sensitivity can be flexibly adjusted by adjusting the overlap area between the first electrode portion 25 and the first electrode layer 22 without sacrificing the mechanical sensitivity. At the same time, this application has a plurality of first hollow grooves 221 on the first electrode layer 22, each groove corresponding to a first support column 24, and the first support column 24 is connected to the upper and lower films at both ends. The first electrode portion 25 on each first support column 24 together with the inner wall of the first hollow groove 221 constitutes a detection capacitor. The output of multiple detection capacitors in parallel (or differentially configured) is equivalent to "discrete small deformation series superposition". This can effectively average the nonlinear response of the central area and the edge area caused by boundary constraints or local wrinkles, making the overall capacitance change tend to be linear. It effectively suppresses high-order nonlinear distortion under large deflection and complex load, thus achieving high sensitivity, high linearity and good reliability in a wide dynamic range.

[0077] In the embodiment of the present application, a sealed cavity is formed between the first insulating film 21 and the second insulating film 23, and the cavity is filled with a gas having a low viscosity coefficient (such as nitrogen, helium) or a low pressure (vacuum or near vacuum). Such a setting can reduce the resistance force (viscous damping) of gas molecules to the movement of the insulating film, making the insulating film respond more quickly to minute pressure changes, reducing the noise amplitude, enhancing the signal response, and improving the signal-to-noise ratio.

[0078] Further, referring to Figures 2 to 5 , in the embodiment disclosed in the present application, the first electrode portion 25 is designed to be in imitation of the first hollow groove 221.

[0079] Specifically, referring to Figure 2 and Figure 4 , the first hollow groove 221 can be a cross-shaped groove. Referring to Figure 3 , the first hollow groove 221 can be a spiral groove. Referring to Figure 5 , the first hollow groove 221 can be a round hole-shaped groove.

[0080] Specifically, when the first hollow groove 221 is a round hole-shaped groove, the first electrode portion 25 is cylindrical, and the first electrode portion 25 and the first support column 24 are coaxial. In some embodiments, the diameter of the first electrode portion 25 is greater than the diameter of the first support column 24. In some embodiments, the diameter of the first electrode portion 25 is equal to the diameter of the first support column 24. When the first hollow groove 221 is a cross-shaped groove or a spiral groove, the facing area of the first electrode portion 25 and the first electrode layer 22 in the direction parallel to the surface of the substrate 1 is significantly increased, the detection of capacitance changes is more sensitive, the electrical sensitivity is improved, and the signal-to-noise ratio of the MEMS sensor is further improved. The combination of different groove types and the dimensions of the first electrode portion 25 can be optimized according to the measurement range and the required resolution to further amplify the capacitance response while maintaining the mechanical sensitivity, achieving the detection performance of high linearity and wide dynamic range.

[0081] It should be noted that, in order to increase the facing area of the first electrode portion 25 and the first electrode layer 22 in the direction parallel to the surface of the substrate 1, the first hollow groove 221 can also be in the shapes of "worker", "bow", "king", etc., and the first electrode portion 25 is designed to be in imitation of the first hollow groove 221.

[0082] Continuing to refer to Figures 2 to 5 , in the embodiment disclosed in the present application, the first electrode layer 22 includes a plurality of circular ring distribution areas 222 that are concentrically arranged based on the structural center of the first electrode layer 22 and are radially spaced. Within each circular ring distribution area 222, the first hollow grooves 221 are circumferentially spaced apart, and the first support column 24 is located at the structural center corresponding to the first hollow groove 221.

[0083] This application arranges the first hollowed-out grooves 221 in concentric annular distribution areas 222, enabling the detection capacitors on each annular distribution area 222 to be evenly spaced circumferentially, and achieving uniform coverage from the center to the edge by adjusting the detection capacitor density at different radii. Multiple discrete first support pillars 24 support the insulating films on both sides, suppressing nonlinear deformation of the insulating film from the center to the edge, achieving approximate translation, and providing stable support within the sealed cavity, avoiding mechanical failure caused by air blowing or drops, and significantly improving the robustness of the device. This design can effectively average the nonlinear response of the central and edge regions caused by boundary constraints and local wrinkles in space, making the final output tend to have linear characteristics; at the same time, the multi-point distribution also concentrates and disperses the strain under large deflection or impact loads to each unit, significantly suppressing higher-order distortion components. Therefore, the MEMS sensor disclosed in this application can maintain the high mechanical sensitivity brought by dual-film actuation in a wide dynamic range, and can also obtain high electrical sensitivity by flexibly adjusting the electrode overlap area, while taking into account excellent linearity and long-term reliability.

[0084] It is worth mentioning that the concentrically arranged annular distribution areas 222 conform to the deformation of the insulating film, which expands uniformly from the center to the edge, making the load response of each detection capacitor more consistent and free from directional deviation. The outer annular distribution area 222 can accommodate more detection capacitors, while the inner annular distribution area 222 appropriately reduces the number of detection capacitors, effectively improving the positive signal output of the effective capacitance area. Simultaneously, the number of capacitor units in the annular distribution areas 222 with different radii can be independently increased or decreased, flexibly optimizing local sensitivity and linearity for the different stiffness characteristics of the central and edge regions. Furthermore, the uniform distribution of detection units along all circumferential directions in the annular distribution area 222 can more effectively offset the nonlinear distortion caused by boundary constraints and local wrinkles, ensuring both high linearity and high reliability over a wide dynamic range.

[0085] In some embodiments, the first hollow groove 221 may also be arranged in an array along the first direction and the second direction, the first direction and the second direction intersect, and both are parallel to the surface of the substrate 1.

[0086] Reference Figure 6 In some embodiments, the first electrode layer 22 further includes a central expansion groove 223 concentrically disposed with the structural center of the first electrode layer 22. The central expansion groove 223 includes a first through groove 2231 extending radially along the annular distribution area 222. Each first through groove 2231 is distributed circumferentially along the annular distribution area 222 and is interconnected with each other. The first support column 24 in the central expansion groove 223 is located at the structural center of the first electrode layer 22, and the first electrode part 25 connected to the first support column 24 is designed to conform to the central expansion groove 223.

[0087] The central capacitor formed by the wall of the central expansion slot 223 and the outer wall of the corresponding first electrode portion 25 has a significantly larger facing area than the detection capacitor formed by the wall of the first hollow slot 221 and the outer wall of the corresponding first electrode portion 25. This central capacitor allows the MEMS sensor to produce a considerable capacitance change even under minimal deflection, enhancing the electrical sensitivity of the MEMS sensor. The coupling effect between the central capacitor and the detection capacitor disperses and spatially distributes nonlinear deviations caused by boundary constraints or local wrinkles, making the overall output more linear. By adjusting the width and depth of each first through slot 2231 in the central expansion slot 223, stress can be distributed across multiple points, further improving the long-term reliability of the sensor.

[0088] Reference Figure 7 In some embodiments, the central expansion slot 223 further includes a second through slot 2232, which corresponds one-to-one with the first through slot 2231. The second through slot 2232 extends circumferentially along the annular distribution area 222 and is distributed at intervals along the circumferential direction, and is connected to the end of the corresponding first through slot 2231 that is away from the structural center of the first electrode layer 22.

[0089] Specifically, in some other embodiments, reference is made to Figure 8 The first electrode layer 22 includes a first distribution area 224 concentrically disposed with the structural center of the first electrode layer 22. The projection of the first distribution area 224 in the thickness direction of the substrate 1 is circular. Each first hollow groove 221 is distributed circumferentially along the first distribution area 224, and each first hollow groove 221 includes a radially extending first groove 2211 and at least one circumferentially extending second groove 2212. The first groove 2211 and the second groove 2212 are connected. The first support column 24 in each first hollow groove 221 is located at the intersection of the second groove 2212 and the first groove 2211.

[0090] Specifically, the circumferentially extending second groove 2212 and second through groove 2232 both increase the surface overlap area between the first electrode portion 25 and the first electrode layer 22, enabling a larger capacitance change even under small displacements, thereby improving the electrical sensitivity of the MEMS sensor and enhancing its signal output. The radially extending first groove 2211 and the first electrode portion 25 form a flexible hinge at the first support post 24, ensuring that the first electrode portion 25 can move uniformly under large deflections or non-uniform loads. This design optimizes electrical sensitivity and effectively suppresses high-order nonlinear distortion under large deformation conditions, achieving high sensitivity, high linearity, and excellent reliability over a wide dynamic range.

[0091] In some embodiments, the first insulating film 21 and the second insulating film 23 each include a first film layer 211, a second film layer 212 and a third film layer 213 arranged sequentially along the thickness direction of the substrate 1, wherein the first film layer 211 and the third film layer 213 are positive stress layers and the second film layer 212 is a negative stress layer.

[0092] The alternating superposition of the first film layer 211 (positive stress), the second film layer 212 (negative stress), and the third film layer 213 (positive stress) allows the internal stress of the insulating film to self-balance, significantly suppressing the initial bending and warping of the insulating film. This ensures that the film surface remains flat after manufacturing and packaging. Simultaneously, the reduced net stress of the insulating film improves its compliance (i.e., the degree of deflection under the same external force), resulting in greater displacement under the same pressure and enhanced mechanical sensitivity. Furthermore, by combining this with multi-point detection capacitor array detection, asymmetric strain and higher-order distortion caused by initial warping can be further reduced, noise can be lowered, and ultimately, the MEMS sensor can simultaneously possess excellent linearity, sensitivity, and long-term reliability over a wide dynamic range.

[0093] Further, in some embodiments, the first support post 24 includes a first conductive segment 241 and a first insulating segment 242 connected together, and a first electrode portion 25 is connected between the first conductive segment 241 and the first insulating segment 242. The first conductive segment 241 is connected to one of the first insulating film 21 and the second insulating film 23, and the first insulating segment 242 is connected to the other of the first insulating film 21 and the second insulating film 23. An electrical connection wire 29 is laid on the insulating film connected to the first conductive segment 241, and the first conductive segment 241 is connected to the electrical connection wire 29. (Refer to...) Figure 1 In this embodiment, the first conductive segment 241 is connected to the first insulating film 21, the first insulating segment 242 is connected to the second insulating film 23, and the electrical connection line 29 is laid on the first insulating film 21. In this embodiment, both the first insulating film 21 and the second insulating film 23 are made of insulating material, and their vibration process directly drives the first electrode portion 25 to move and output a corresponding electrical signal. Compared with conventional MEMS sensors using conductive diaphragms, this embodiment eliminates the parasitic capacitance between the diaphragm and the substrate 1, significantly increasing the proportion of effective capacitance in the total capacitance, thereby increasing the output signal amplitude and improving the signal-to-noise ratio.

[0094] Reference Figure 9In some other embodiments, the two ends of the first support column 24 are respectively second conductive segments 243, and a second insulating segment 244 is connected between the two second conductive segments 243. A first electrode portion 25 is connected between each second conductive segment 243 and the second insulating segment 244. Electrical connection lines 29 are laid on both the first insulating film 21 and the second insulating film 23, and each second conductive segment 243 is connected to the electrical connection line 29 on the corresponding insulating film. Among them, on the same first support column 24, the sidewalls of the two first electrode portions 25 respectively form detection capacitors with the sidewalls of the corresponding first hollow grooves 221, and the two detection capacitors constitute a set of differential capacitors.

[0095] A set of differential capacitors is formed by the first electrode portions 25 at both ends of the same first support column 24. The two detection capacitors change synchronously and in opposite directions with the deflection. The differential output is approximately the sum of the two. It can maintain a linear response in the large deflection range and broaden the dynamic measurement range.

[0096] Reference Figure 1 In some embodiments, a first support layer 26 is provided between the first insulating film 21 and the substrate 1, and a first cavity 261 is formed through the first support layer 26; a second support layer 27 is provided between the first insulating film 21 and the first electrode layer 22, and a second cavity 271 is formed through the second support layer 27; a third support layer 28 is provided between the second insulating film 23 and the first electrode layer 22, and a third cavity 281 is formed through the third support layer 28; in the thickness direction of the substrate 1, the projections of the first cavity 261, the second cavity 271, the third cavity 281, and the back cavity 11 overlap.

[0097] Reference Figure 10 In some embodiments, the MEMS sensor further includes at least one second detection unit 3, which is located on the side of the first detection unit 2 away from the substrate 1.

[0098] The second detection unit 3 includes a second electrode layer 31 and a third insulating film 32. Multiple second perforated slots 311 are spaced apart on the second electrode layer 31. The third insulating film 32 is located on the surface of the second electrode layer 31 facing away from the second insulating film 23, and is positioned opposite to the second electrode layer 31 with a gap. Each second perforated slot 311 contains a second support post 33, and both ends of the second support post 33 are connected to the insulating films on both sides of the second electrode layer 31. A second electrode portion 34 is provided between the two ends of each second support post 33. The sidewall of the second electrode portion 34 is spaced from the inner wall of the corresponding second perforated slot 311, and together they form a second detection capacitor.

[0099] It should be noted that the structural features of the second support column 33, the second hollow groove 311, and the second electrode part 34 in the second detection unit 3 are the same as those of the first support column 24, the first hollow groove 221, and the first electrode part 25 in the first detection unit 2, and will not be described again here.

[0100] In this embodiment, the arrangement of the second support column 33 in the second detection unit 3 is the same as the arrangement of the first support column 24 in the first detection unit 2. In some other embodiments, the arrangement of the support columns in the two detection units may be different.

[0101] In some embodiments, the ends of the support columns on both sides of the insulating film between two adjacent detection units are electrically connected to the same electrical connection line 29, which is located on the side surface of the insulating film facing away from or towards the substrate 1.

[0102] Reference Figure 10 When there is only one second detection unit 3, the second electrode layer 31 is located between the third insulating film 32 and the second insulating film 23. Inside the second detection unit 3, the second support column 33, which is connected to the second insulating film 23, passes through the second insulating film 23 and is connected to the first support column 24 in the first detection unit 2.

[0103] Specifically, when both ends of the second support post 33 are conductive segments, electrical connection lines 29 are laid on the side of the third insulating film 32 facing the substrate 1, the side of the second insulating layer away from the substrate 1, and the side of the first insulating layer away from the substrate 1. The second support post 33, connected to the second insulating film 23, passes through the second insulating film 23 and connects to the first support post 24 in the first detection unit 2, so that the electrical signal of the end of the first support post 24 in the first detection unit 2 away from the substrate 1 is output through the electrical connection line 29 on the side of the second insulating layer away from the substrate 1.

[0104] Reference Figure 11 When there are multiple second detection units 3, this application provides an example of having two second detection units 3. In at least one of the two adjacent second detection units 3, the second electrode layer 31 is located between two third insulating films 32. In this second detection unit 3, a second support column 33 connected to the third insulating film 32 passes through the third insulating film 32 and is connected to the second support column 33 in the other second detection unit 3.

[0105] Specifically, when both ends of the second support post 33 are conductive segments, electrical connection lines 29 are laid on the side of the third insulating film 32 of the second detection unit 3 that is relatively far from the substrate 1 facing the substrate 1, the side of the third insulating film 32 of the second detection unit 3 that is relatively close to the substrate 1 facing away from the substrate 1, the side of the second insulating layer that faces away from the substrate 1, and the side of the first insulating layer that faces away from the substrate 1. The second support post 33 passes through the third insulating film 32 and is connected to the second support post 33 in another second detection unit 3, so that the second support posts 33 in the two second detection units 3 can output through the same layer of electrical connection lines 29.

[0106] It should be noted that, in some embodiments, the second support post 33 in each second detection unit 3 does not penetrate the insulating film, and an electrical connection line 29 is laid on one side surface of the insulating film connected to the conductive segment of the second support post 33. In some embodiments, the second support post 33 in each second detection unit 3 may have a structure in which one end is a conductive segment and the other end is an insulating segment.

[0107] It is worth mentioning that in the second detection unit 3, a support layer is provided between the second electrode layer 31 and the insulating films on both sides, and the support layer is provided with a cavity.

[0108] By stacking multiple detection units in the thickness direction of substrate 1, the detection capacitors in each detection unit are connected in parallel or output differentially to form a single-layer equivalent capacitor.

[0109] After the equivalent capacitances of multiple detection units are connected in parallel, the total capacitance change caused by pressure disturbance, ΔC = ∑ΔCi (where ΔCi is the capacitance change of the equivalent capacitance of each detection unit), can achieve a larger capacitance change compared to a single detection unit, thereby improving the electrical sensitivity of the MEMS sensor. Simultaneously, stacking multiple sets of capacitors effectively amplifies ΔC, increasing the ΔCe / Cp ratio (where Cp is the parasitic capacitance), thus improving the signal-to-noise ratio of the output signal.

[0110] This application also discloses an electronic device including any of the MEMS sensors disclosed above.

[0111] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0112] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0113] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0114] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A MEMS sensor, characterized in that, include: The base (1) has a back cavity (11) on one side surface; The first detection unit (2) includes: The first insulating film (21) is located on the side surface of the substrate (1) where the back cavity (11) is formed; The first electrode layer (22) is located on the side surface of the first insulating film (21) away from the substrate (1), and is disposed opposite to the first insulating film (21) and spaced apart; a plurality of first hollow grooves (221) are spaced apart on the first electrode layer (22); The second insulating film (23) is located on the side surface of the first electrode layer (22) away from the first insulating film (21), and is disposed opposite to the first electrode layer (22) and has a gap; Multiple first support columns (24) pass through the corresponding first hollow slots (221) and are connected at both ends to the first insulating film (21) and the second insulating film (23) respectively. Among them, a first electrode portion (25) is provided between the two ends of each of the first support columns (24). The side wall of the first electrode portion (25) and the inner wall of the corresponding first hollow groove (221) are spaced together and together form a detection capacitor. When the first insulating film (21) and / or the second insulating film (23) vibrate to drive the first support column (24) to move in the thickness direction of the substrate (1), the projection of the first electrode portion (25) and the projection of the first electrode layer (22) at least partially overlap in the direction parallel to the surface of the substrate (1).

2. The MEMS sensor according to claim 1, characterized in that, The first electrode part (25) is designed to mimic the shape of the first hollow groove (221).

3. The MEMS sensor according to claim 2, characterized in that, The first hollow groove (221) includes a circular hole groove, a cross-shaped groove, and a spiral groove.

4. The MEMS sensor according to claim 2, characterized in that, The first electrode layer (22) includes a plurality of annular distribution regions (222) that are concentrically arranged and radially spaced based on the structural center of the first electrode layer (22); Within each of the circular distribution areas (222), the first hollowed-out grooves (221) are distributed circumferentially along the circular distribution area (222), and the first support column (24) is located at the structural center corresponding to the first hollowed-out groove (221).

5. The MEMS sensor according to claim 4, characterized in that, The first electrode layer (22) further includes a central expansion groove (223) concentrically disposed with the structural center of the first electrode layer (22). The central expansion groove (223) includes a first through groove (2231) extending radially along the annular distribution area (222). Each of the first through grooves (2231) is distributed circumferentially along the annular distribution area (222) and is interconnected with each other. The first support column (24) in the central expansion groove (223) is located at the structural center of the first electrode layer (22), and the first electrode part (25) connected to the first support column (24) is designed to mimic the shape of the central expansion groove (223).

6. The MEMS sensor according to claim 5, characterized in that, The central expansion slot (223) further includes a second through slot (2232), which is connected to the first through slot (2231). The second through slot (2232) extends circumferentially along the annular distribution area (222) and is distributed at intervals along the circumferential direction.

7. The MEMS sensor according to claim 2, characterized in that, The first electrode layer (22) includes a first distribution area (224) concentrically disposed with the structural center of the first electrode layer (22), and the projection of the first distribution area (224) in the thickness direction of the substrate (1) is circular; Each of the first hollow slots (221) is distributed circumferentially along the first distribution area (224), and each of the first hollow slots (221) includes a radially extending first slot (2211) and at least one circumferentially extending second slot (2212). The first slot (2211) and the second slot (2212) are connected. The first support column (24) in each of the first hollow slots (221) is located at the intersection of the second slot (2212) and the first slot (2211).

8. The MEMS sensor according to claim 1, characterized in that, Both the first insulating film (21) and the second insulating film (23) include a first film layer (211), a second film layer (212) and a third film layer (213) arranged sequentially along the thickness direction of the substrate (1). The first film layer (211) and the third film layer (213) are positive stress layers, and the second film layer (212) is a negative stress layer.

9. The MEMS sensor according to claim 1, characterized in that, The first support column (24) includes a first conductive segment (241) and a first insulating segment (242) connected to each other, and the first electrode portion (25) is connected between the first conductive segment (241) and the first insulating segment (242); The first conductive segment (241) is connected to one of the first insulating film (21) and the second insulating film (23), and the first insulating segment (242) is connected to the other of the first insulating film (21) and the second insulating film (23). An electrical connection line (29) is laid on the insulating film connected to the first conductive segment (241), and the first conductive segment (241) is connected to the electrical connection line (29).

10. The MEMS sensor according to claim 1, characterized in that, The first support column (24) has two ends of a second conductive segment (243), and a second insulating segment (244) is connected between the two second conductive segments (243). A first electrode part (25) is connected between each second conductive segment (243) and the second insulating segment (244). Electrical connection lines (29) are laid on the first insulating film (21) and the second insulating film (23), and each second conductive segment (243) is connected to the electrical connection line (29) on the corresponding insulating film. In this context, on the same first support column (24), the sidewalls of the two first electrode portions (25) respectively form detection capacitors with the sidewalls of the corresponding first hollow groove (221), and the two detection capacitors constitute a set of differential capacitors.

11. The MEMS sensor according to claim 1, characterized in that, Also includes: At least one second detection unit (3) is located on the side of the first detection unit (2) away from the substrate (1); The second detection unit (3) includes: The second electrode layer (31) has a plurality of second hollow grooves (311) spaced apart on it; The third insulating film (32) is located on the side surface of the second electrode layer (31) away from the second insulating film (23), and is disposed opposite to the second electrode layer (31) and has a gap; The second support column (33) passes through the second hollow groove (311) of the corresponding second electrode layer (31), and the two ends of the second support column (33) are respectively connected to the insulating film on both sides of the second electrode layer (31); a second electrode part (34) is provided between the two ends of each second support column (33), and there is a gap between the side wall of the second electrode part (34) and the inner wall of the corresponding second hollow groove (311), which together constitute the second detection capacitor.

12. The MEMS sensor according to claim 11, characterized in that, When there is one second detection unit (3), The second electrode layer (31) is located between the third insulating film (32) and the second insulating film (23); inside the second detection unit (3), the second support column (33) connected to the second insulating film (23) passes through the second insulating film (23) and is connected to the first support column (24) in the first detection unit (2); When there are multiple second detection units (3), At least one of the two adjacent second detection units (3) has a second electrode layer (31) located between the two third insulating films (32). In this second detection unit (3), a second support column (33) connected to the third insulating film (32) passes through the third insulating film (32) and is connected to the second support column (33) in the other second detection unit (3).

13. The MEMS sensor according to claim 11, characterized in that, The ends of the support columns on both sides of the insulating film between two adjacent detection units are electrically connected to the same electrical connection line (29), which is located on one side surface of the insulating film.

14. The MEMS sensor according to claim 1, characterized in that, A first support layer (26) is provided between the first insulating film (21) and the substrate (1), and a first chamber (261) is provided through the first support layer (26); a second support layer (27) is provided between the first insulating film (21) and the first electrode layer (22), and a second chamber (271) is provided through the second support layer (27); a third support layer (28) is provided between the second insulating film (23) and the first electrode layer (22), and a third chamber (281) is provided through the third support layer (28). In the thickness direction of the substrate (1), the projections of the first chamber (261), the second chamber (271), the third chamber (281), and the back cavity (11) overlap.

15. An electronic device, characterized in that, Including the MEMS sensor as described in any one of claims 1-14.

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