A spiral-beam MEMS impact sensor and sensing device

Abstract

The utility model provides a kind of spiral beam MEMS impact sensor and sensing device, it includes support mechanism, impact floating mechanism and cover plate, support mechanism includes substrate, electrode assembly on substrate, impact floating mechanism includes bonding frame body, spiral beam, moving electrode.The bonding frame body is connected with substrate, one end of spiral beam is connected with inner wall in bonding frame body, one end is connected with moving electrode and is around it in spiral structure, moving electrode and electrode assembly gap fit and center line coincide;Cover plate is arranged with support mechanism and is connected with bonding frame body on both sides of impact floating mechanism.Spiral beam structure improves elastic deformation and fatigue resistance, ensures impact displacement stability and prevents stress damage, prolongs service life.Three stable bonding form closed sensing space, impact resistance, dust and water vapor isolation, symmetric design reduces interference;The design of moving electrode and electrode assembly ensures that displacement is in effective detection range, improves precision and sensitivity.Compared with existing sensor, its performance is significantly improved in many aspects, and the application range is wider.

Description

Technical Field

[0001] This utility model relates to the field of sensor technology, specifically to a spiral beam MEMS impact sensor and sensing device. Background Technology

[0002] With the rapid development of fields such as automotive safety, aerospace, and industrial equipment monitoring, the demand for impact signal detection is becoming increasingly stringent. Sensors are required not only to accurately capture weak impact signals but also to operate stably under high impact conditions ranging from hundreds to thousands of grams, while ensuring structural stability and signal consistency over long-term use. Silicon-based microelectromechanical systems (MEMS) impact sensors, with their advantages of small size, high integration, and low cost, have become the mainstream technology in this field. Their core structure consists of a fixed substrate, an elastic element, and a mass block. The elastic element, as the key component connecting the fixed substrate and the mass block, directly determines the sensor's sensitivity, range, and reliability.

[0003] Currently, silicon-based MEMS impact sensors commonly use cantilever beams or folded beams as elastic elements. However, under high-g impact environments, these traditional structures suffer from a technical bottleneck where sensitivity, range, and reliability are mutually exclusive. According to the principles of materials mechanics, the bending stiffness of the elastic element directly affects sensor performance: to improve sensitivity, the bending stiffness of the beam needs to be reduced so that the mass block generates a larger inertial displacement under impact load, facilitating electrical signal detection; while to meet the range requirements of high-g impacts, the bending stiffness of the beam needs to be increased to prevent the beam from breaking or undergoing permanent plastic deformation due to excessive displacement. The length of traditional cantilever beams is limited by the chip packaging size, resulting in a narrow range of bending stiffness adjustment. If the stiffness is reduced by thinning the beam to improve sensitivity, the beam's impact resistance will decrease sharply, making it unable to withstand high-g impact loads. Although folded beams extend the effective length through bending structures, the degree of length extension is limited by the planar topology, and the reduction in bending stiffness is insufficient, making it difficult to find a balance between high sensitivity and high range.

[0004] Meanwhile, the reliability and measurement accuracy of traditional beam structures are significantly reduced due to the inherent limitations of the structure itself. Cantilever beams, with their asymmetrical structure of one fixed end and the other suspended, concentrate stress at the root of the fixed end under impact loads, making them prone to fatigue cracks and even fracture. Folded beams also exhibit localized stress concentration at the bends; under repeated impacts or high-g impacts, the stress concentration areas will fail first, drastically shortening the sensor's lifespan. Furthermore, the geometric asymmetry of traditional beam structures makes them prone to inducing higher-order modes such as torsion and lateral oscillations in impact responses. These non-target vibrations are superimposed on the effective detection signal. Simultaneously, the anisotropy of the asymmetrical structure induces inter-axis coupling effects, leading to increased measurement errors and failing to meet the requirements of high-precision impact detection.

[0005] In summary, existing conventional silicon-based MEMS impact sensors, due to structural design and process limitations, cannot overcome the mutually exclusive bottlenecks of sensitivity, measurement range, and reliability, making it difficult to meet the high-precision and high-stability detection requirements under high-g impact environments. Summary of the Invention

[0006] Therefore, the technical problem to be solved by this utility model is to overcome the problem that the impact sensors in the prior art are difficult to meet the high precision and high stability detection requirements under high g impact environment, and to provide a spiral beam MEMS impact sensor and sensing device.

[0007] To address the aforementioned technical problems, this utility model provides a helical beam MEMS impact sensor, comprising: a support mechanism including a substrate and an electrode assembly disposed on the substrate; an impact floating mechanism including a bonding frame, at least one helical beam, and a movable electrode, the bonding frame being disposed on the substrate and bonded to the side of the substrate where the electrode assembly is disposed, one end of the helical beam being connected to the inner wall of the bonding frame, and the other end being connected to the movable electrode, the main body of the helical beam being arranged in a helical structure around the outer periphery of the movable electrode, the movable electrode being clearance-fitted with the electrode assembly, and the centerline of the movable electrode coinciding with the centerline of the electrode assembly; and a cover plate, the cover plate and the support mechanism being respectively disposed on opposite sides of the impact floating mechanism in the thickness direction, and the cover plate being bonded to the bonding frame.

[0008] In one embodiment of the present invention, the impact floating mechanism includes a plurality of helical beams, which are evenly spaced around the outer surface of the movable electrode.

[0009] In one embodiment of the present invention, the impact floating mechanism further includes a plurality of limiting posts, which are arranged around the outer surface of the movable electrode, and both ends of any one of the limiting posts are respectively connected to the substrate and the cover plate.

[0010] In one embodiment of the present invention, the movable electrode is provided with a plurality of limiting grooves, the plurality of limiting grooves being recessed inward from the outer surface of the movable electrode, and the plurality of limiting posts being embedded in the plurality of limiting grooves one by one.

[0011] In one embodiment of this utility model, the cover plate is provided with a first movable groove, which is recessed inward from the side of the cover plate facing the impact floating mechanism to avoid the moving electrode.

[0012] In one embodiment of the present invention, the substrate is provided with a protrusion, the protrusion is disposed around the edge of the substrate and protrudes toward the impact floating mechanism, the protrusion is bonded to the bonding frame, and the protrusion surrounds a second movable groove to avoid the moving electrode.

[0013] In one embodiment of the present invention, the electrode assembly includes an annular positive electrode and an annular negative electrode, which are alternately arranged in a direction extending outward from the center of the electrode assembly to its edge.

[0014] In one embodiment of the present invention, the electrode assembly further includes a positive electrode pad and a negative electrode pad disposed on the substrate. One end of the annular positive electrode is disposed corresponding to the movable electrode, and the other end extends to the edge of the substrate and is connected to the positive electrode pad. One end of the annular negative electrode is disposed corresponding to the movable electrode, and the other end extends to the edge of the substrate and is connected to the negative electrode pad.

[0015] In one embodiment of this utility model, the thickness of the cover plate is 380~420μm, the thickness of the bonding frame is 280~320μm, and the thickness of the substrate is 380~420μm, and is the same as the thickness of the cover plate.

[0016] This invention also provides a sensing device, which includes the aforementioned spiral beam MEMS impact sensor.

[0017] The above-mentioned technical solution of this utility model has the following advantages compared with the prior art: In the spiral beam MEMS impact sensor and sensing device described in this utility model, the spiral beam is arranged in a spiral structure around the outer periphery of the moving electrode. Compared with traditional straight beams or other structural forms, this spiral structure can significantly improve the elastic deformation capacity and fatigue resistance of the beam under impact. This allows the sensor to produce a stable and accurately detectable displacement response when subjected to impacts of different intensities and directions, while effectively avoiding damage caused by structural stress concentration, thus significantly extending the service life and operational reliability of the sensor.

[0018] Meanwhile, the support mechanism, impact floating mechanism, and cover plate are stably bonded together, constructing a robust and enclosed sensing space. This not only possesses good mechanical strength, capable of withstanding certain external impacts and vibrations, but also, through a reasonable spatial layout, effectively isolates external environmental interference factors such as dust and moisture from affecting the internal electrode assembly and the precision of the moving electrode fit, ensuring the sensor's detection stability in complex environments. Furthermore, the symmetrical design of the structure reduces additional interference caused by assembly errors or external vibrations, further improving detection accuracy. In addition, the moving electrode and electrode assembly employ a clearance fit and coincident centerline design, ensuring that the displacement of the moving electrode under impact remains within the effective detection range of the electrode assembly, avoiding detection signal distortion caused by displacement deviation, and significantly improving the sensor's detection sensitivity and accuracy.

[0019] Compared with existing conventional impact sensors, the spiral beam MEMS impact sensor and sensing device described in this utility model have significant improvements in elastic deformation capability, fatigue resistance, service life, structural sealing, anti-interference capability, detection accuracy and sensitivity, manufacturing convenience, cost control and miniaturization adaptability, and have a wider range of applications, giving them a significant advantage in the industry. Attached Figure Description

[0020] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0021] Figure 1 This is a three-dimensional structural schematic diagram of the spiral beam MEMS impact sensor in a preferred embodiment of this utility model; Figure 2 yes Figure 1 The diagram shows a three-dimensional structure of the cover plate in the spiral beam MEMS impact sensor. Figure 3 yes Figure 1 The diagram shows a three-dimensional structural schematic of the impact floating mechanism and support mechanism in the spiral beam MEMS impact sensor. Figure 4 yes Figure 1 The diagram shows a three-dimensional structural schematic of the support mechanism in the spiral beam MEMS impact sensor.

[0022] Explanation of reference numerals in the accompanying drawings: 100, cover plate; 110, first movable groove; 200, impact floating mechanism; 210, bonding frame; 220, helical beam; 230, movable electrode; 240, limiting post; 300, support mechanism; 310, substrate; 311, protrusion; 312, second movable groove; 320, electrode assembly; 321, annular positive electrode; 322, annular negative electrode; 323, positive electrode pad; 324, negative electrode pad. Detailed Implementation

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention.

[0024] Example 1:

[0025] See Figure 1 As shown, this embodiment provides a helical beam MEMS impact sensor, which includes: a support mechanism 300, the support mechanism 300 including a substrate 310 and an electrode assembly 320, the electrode assembly 320 being disposed on the substrate 310; and an impact floating mechanism 200, the impact floating mechanism 200 including a bonding frame 210, at least one helical beam 220, and a movable electrode 230, the bonding frame 210 being disposed on the substrate 310 and bonded to the side of the substrate 310 where the electrode assembly 320 is located, and one of the helical beams 220... One end is connected to the inner wall of the bonding frame 210, and the other end is connected to the movable electrode 230. The main body of the spiral beam 220 is arranged in a spiral structure around the outer periphery of the movable electrode 230. The movable electrode 230 is clearance-fitted with the electrode assembly 320, and the center line of the movable electrode 230 coincides with the center line of the electrode assembly 320. The cover plate 100 and the support mechanism 300 are respectively disposed on opposite sides of the impact floating mechanism 200 in the thickness direction, and the cover plate 100 is bonded to the bonding frame 210.

[0026] In the spiral beam MEMS impact sensor and sensing device described in this utility model, the spiral beam 220 is arranged in a spiral structure around the outer periphery of the moving electrode 230. Compared with traditional straight beams or other structural forms, this spiral structure can significantly improve the elastic deformation capability and fatigue resistance of the beam under impact. This allows the sensor to generate a stable and accurately detectable displacement response when subjected to impacts of different intensities and directions, while effectively avoiding damage caused by structural stress concentration, thus significantly extending the service life and operational reliability of the sensor.

[0027] Furthermore, the support mechanism 300, the impact floating mechanism 200, and the cover plate 100 are stably bonded together, constructing a robust and enclosed sensing space. This not only possesses good mechanical strength, capable of withstanding certain external impacts and vibrations, but also, through a reasonable spatial layout, effectively isolates external environmental interference factors such as dust and moisture from affecting the fitting accuracy of the internal electrode assembly 320 and the moving electrode 230, ensuring the sensor's detection stability in complex environments. The symmetrical design of the structure also reduces additional interference caused by assembly errors or external vibrations, further improving detection accuracy. In addition, the moving electrode 230 and the electrode assembly 320 employ a clearance fit and coincident centerline design, ensuring that the displacement of the moving electrode 230 under impact remains within the effective detection range of the electrode assembly 320, avoiding signal distortion caused by displacement deviation, and significantly improving the sensor's detection sensitivity and accuracy.

[0028] Specifically, see Figure 1 and Figure 2 As shown, the cover plate 100 and the support mechanism 300 are respectively disposed on opposite sides of the impact floating mechanism 200 in the thickness direction, and are bonded to the bonding frame 210. The cover plate 100, the substrate 310, and the bonding frame 210 together form an overall enclosed sensing space, which can effectively isolate interference factors such as dust, water vapor, and corrosive gases in the external environment, prevent these impurities from entering the interior and affecting the fitting accuracy of the electrode assembly 320 and the moving electrode 230, and ensure the detection stability of the sensor in complex environments; at the same time, the cover plate 100 can also block small foreign objects from impacting the internal core components, preventing the core components from being damaged by accidental impact.

[0029] In this embodiment, the thickness of the cover plate 100 is 400 μm, the thickness of the bonding frame 210 is 300 μm, and the thickness of the substrate 310 is 400 μm, the same as the thickness of the cover plate 100. In different embodiments, the thickness of the cover plate 100 can be configured to 380~420 μm according to actual applicable needs, the thickness of the bonding frame 210 can be configured to 280~320 μm according to actual applicable needs, and the thickness of the substrate 310 can be configured to 380~420 μm according to actual applicable needs. This utility model does not impose specific limitations on this. The cover plate 100, with a thickness of 380-420 μm, provides sufficient rigidity to resist external impacts, vibrations, and foreign object collisions, ensuring the sealing of the internal sensing space. It also accommodates the first movable slot 110 to reserve displacement space for the moving electrode 230, preventing the sensor from becoming too large. Furthermore, its equal thickness with the substrate 310 ensures a symmetrical structure in the thickness direction, reducing uneven assembly stress and optimizing installation and integration. The bonding frame 210, with a thickness of 280-320 μm, provides a stable connection base for the helical beam 220, ensuring it does not loosen or break during elastic deformation, thus guaranteeing the stable displacement of the moving electrode 230. Additionally, being thinner than the cover plate 100 and the substrate 310, it provides additional thickness space for the moving electrode 230. The displacement is pre-reserved with reasonable space to balance the connection strength and displacement requirements. It can also adapt to the overall height of the impact floating mechanism 200, ensuring that the initial gap between the moving electrode 230 and the electrode assembly 320 on the substrate 310 is reasonable, providing stable initial parameters for capacitance detection. The thickness of the substrate 310, which is 380~420μm, can provide a stable mounting platform for the electrode assembly 320, avoiding bending deformation under load to ensure the positional accuracy of the electrode assembly 320 and the coincidence of the center line with the moving electrode 230, reducing detection errors. At the same time, the equal thickness with the cover plate 100 ensures uniform strength distribution of the upper and lower structures. During impact, it can evenly disperse the impact force to avoid local stress damage, and also provide sufficient space for external circuit connection, taking into account both structural load-bearing capacity and signal transmission.

[0030] Furthermore, the cover plate 100 is provided with a first movable groove 110, which is recessed inward from the side of the cover plate 100 facing the impact floating mechanism 200 to avoid the movable electrode 230. The first movable groove 110 is used to avoid the movable electrode 230. When the sensor is subjected to external impact, the movable electrode 230 in the impact floating mechanism 200 will be displaced under inertia. If the inner side of the cover plate 100 is a flat surface, the displacement of the movable electrode 230 will be physically blocked by the cover plate 100, resulting in the inability to generate effective displacement to change the capacitance parameters with the electrode assembly 320, thereby affecting the detection function of the sensor. However, the recessed space of the first movable groove 110 can provide a buffer area for the displacement of the movable electrode 230 towards the cover plate 100, ensuring that the movable electrode 230 can move freely under impact, without colliding and wearing with the cover plate 100, and can also fully complete the displacement response.

[0031] See Figure 3 As shown, the impact floating mechanism 200 consists of three parts: a bonding frame 210, at least one helical beam 220, and a movable electrode 230. The bonding frame 210 has a ring-shaped frame structure, with one end bonded to the substrate 310 and the other end bonded to the cover plate 100. Supported by the cover plate 100 above and the substrate 310 below, the core components of the impact floating mechanism 200 are stably encapsulated inside the bonding frame 210. Simultaneously, the bonding frame 210 provides a fixed connection point for the helical beam 220, ensuring that the helical beam 220 can elastically deform around the fixed point under impact, rather than shifting as a whole. Furthermore, the ring structure, together with the substrate 310 and the cover plate 100, can construct a closed sensing space, providing basic protection for the internal components.

[0032] One end of the helical beam 220 is connected to the inner wall of the bonding frame 210, and the other end is connected to the movable electrode 230. The main body of the beam is arranged in a helical structure around the outer periphery of the movable electrode 230. Compared with traditional straight beams or other structural forms, this helical structure can significantly improve the elastic deformation capacity and fatigue resistance of the beam: when subjected to impact, the helical structure can buffer the impact energy through the coordinated deformation of multiple turns of the beam, enabling the movable electrode 230 to generate a stable and accurately detectable displacement response, avoiding sudden displacement due to excessive local stress; at the same time, the helical structure disperses the stress generated by the impact, effectively reducing fatigue damage to the beam, significantly extending the service life of the sensor, and ensuring the reliability of long-term operation; in addition, the helical structure arranged around the outer periphery of the movable electrode 230 can also ensure that the movable electrode 230 can obtain a balanced support force under impact in different directions, so that the displacement response has good directional consistency.

[0033] Furthermore, in this embodiment, the impact floating mechanism 200 includes a plurality of helical beams 220, which are evenly spaced around the outer surface of the movable electrode 230. In this embodiment, the plurality of helical beams 220 are symmetrically distributed around the center line of the movable electrode 230, with the spacing between adjacent helical beams 220 remaining consistent. One end of each helical beam 220 is securely connected to the inner wall of the bonding frame 210, while the other end converges and connects to the movable electrode 230, so that the movable electrode 230 is under the cooperative support of the plurality of helical beams 220, forming a symmetrical and stable mechanical structure.

[0034] On the one hand, the evenly spaced helical beams 220 ensure that the movable electrode 230 receives balanced support and elastic deformation feedback when subjected to impacts from different directions. Each helical beam 220 can deform synchronously or collaboratively according to the impact direction and intensity, avoiding local overload and fatigue damage caused by concentrated force on a single helical beam 220, thus significantly extending the service life of the helical beam 220. On the other hand, the symmetrical support structure ensures that the movable electrode 230 always moves along the preset direction during the impact displacement process, thereby effectively reducing displacement deviation and tilting caused by uneven force, preventing the movable electrode 230 from exceeding the effective detection range of the electrode assembly 320, and thus ensuring the stability and accuracy of the sensor detection signal, making the detection results of impact intensity and direction more accurate and reliable. Specifically, this embodiment has four helical beams 220, but the present invention does not specify the number of helical beams 220.

[0035] Furthermore, the movable electrode 230 is a component that directly receives impacts and generates displacement. It forms a clearance fit with the electrode assembly 320, and their center lines coincide. The movable electrode 230 can convert external impacts into detectable mechanical displacements: when an impact acts on the sensor, the movable electrode 230 generates displacement under inertia, thereby changing the capacitance parameters between it and the electrode assembly 320, providing a mechanical displacement basis for signal detection. The clearance fit design ensures that the movable electrode 230 will not make physical contact with the electrode assembly 320 during displacement, avoiding friction wear and short-circuit risks. The center line coincidence design ensures that the displacement of the movable electrode 230 always follows the reference axis of the electrode assembly 320, ensuring that the displacement is always within the effective detection range of the electrode assembly 320, avoiding signal distortion due to displacement deviation, thereby improving the sensor's detection sensitivity and accuracy.

[0036] In this embodiment, the impact floating mechanism 200 further includes multiple limiting posts 240. These limiting posts 240 are arranged around the outer surface of the movable electrode 230, and both ends of any one of the limiting posts 240 are connected to the substrate 310 and the cover plate 100, respectively. The multiple limiting posts 240 are distributed around the outer surface of the movable electrode 230 with the center line of the movable electrode 230 as a reference. Both ends of each limiting post 240 are fixedly connected to the sensor substrate 310 and the cover plate 100, respectively, thereby forming a columnar support that penetrates the space of the impact floating mechanism 200 and connects the upper and lower support structures. Simultaneously, it maintains a preset gap with the movable electrode 230 and does not directly contact the movable electrode 230.

[0037] This design limits the excessive displacement of the movable electrode 230. When the sensor encounters a strong impact exceeding the normal detection range, the movable electrode 230 will undergo significant displacement due to inertia. Without limiting constraints, the movable electrode 230 may violently collide with the cover plate 100, substrate 310, or electrode assembly 320, causing the helical beam 220 to break due to excessive deformation, or the electrode structure to be damaged by the impact. The multiple limiting posts 240 arranged around the outer surface of the movable electrode 230 can physically block its continued movement when the displacement of the movable electrode 230 reaches the critical safety value, preventing the displacement from exceeding the safe range. This effectively protects the core components such as the helical beam 220, movable electrode 230, and electrode assembly 320 from impact damage, improving the sensor's overload resistance and operational safety. At the same time, the symmetrical distribution design of the multiple limiting posts 240 ensures that the movable electrode 230 is subjected to balanced limiting constraints when it displaces in different directions, avoiding localized excessive displacement due to insufficient limiting on one side, further ensuring the comprehensiveness and stability of structural protection.

[0038] Specifically, the movable electrode 230 is provided with multiple limiting grooves, which are recessed inward from the outer surface of the movable electrode 230. Multiple limiting posts 240 are correspondingly embedded in the multiple limiting grooves. The multiple limiting grooves are all formed by the inward recess of the outer surface of the movable electrode 230, and the depth and width of the recess must match the dimensions of the limiting posts 240. This ensures that the overall structural strength of the movable electrode 230 is not weakened due to excessive depth, nor that the fit with the limiting posts 240 fails due to dimensional deviations. At the same time, the number and distribution of the limiting grooves completely correspond to the limiting posts 240, ensuring that each limiting post 240 can be accurately embedded in its corresponding limiting groove, forming a high-precision mating structure.

[0039] See Figure 4 As shown, the support mechanism 300 consists of two parts: a substrate 310 and an electrode assembly 320. These two parts work together to provide a stable foundation for the entire device. The substrate 310 serves as the base of the sensor, and its substrate is preferably glass. On one hand, it stably supports the electrode assembly 320 and the impact floating mechanism 200, thereby ensuring that the relative positions of all internal structures of the sensor remain stable and preventing structural displacement from affecting detection accuracy. On the other hand, the support mechanism 300 provides insulation, effectively preventing electrical interference between the electrode assembly 320 and other external structures, ensuring the purity of the detection signal. Simultaneously, the substrate 310 also provides mechanical support, resisting minor vibrations or impacts from the external environment, preventing deformation of the overall structure, and further maintaining sensing accuracy.

[0040] Furthermore, in this embodiment, the substrate 310 is provided with a protrusion 311. The protrusion 311 is disposed around the edge of the substrate 310 and protrudes towards the impact floating mechanism 200. The protrusion 311 is bonded to the bonding frame 210. The protrusion 311 surrounds a second movable groove 312 to avoid the movable electrode 230. The protrusion 311 is disposed around the edge region of the substrate 310, and its protruding direction is towards the impact floating mechanism 200, thereby forming an annular protrusion structure surrounding the edge of the substrate 310. On the one hand, the protrusion 311 serves as a direct connection carrier between the substrate 310 and the bonding frame 210. Its height is matched to the thickness of the bonding frame 210, enabling it to form a tight and large-area contact with the bonding frame 210. This provides a stable structural foundation for the bonding connection, preventing insufficient bonding strength due to an insufficiently small connection surface or uneven contact. This ensures the stability of the connection between the support mechanism 300 and the impact floating mechanism 200, maintaining the relative positional accuracy of the entire sensor's internal structure. On the other hand, the second movable groove 312 enclosed by the protrusion 311 serves as a movable electrode 230. The displacement under impact provides ample space below. When the movable electrode 230 is displaced towards the substrate 310 due to impact, the second movable groove 312 can prevent the movable electrode 230 from colliding with the surface of the substrate 310. This prevents physical damage to the movable electrode 230 and the substrate 310, and ensures that the movable electrode 230 can generate effective displacement to change the capacitance parameters with the electrode assembly 320, thus ensuring the normal realization of the sensor detection function. Together with the first movable groove 110 on the cover plate 100, they form an upper and lower corresponding structure, providing all-round space avoidance for the displacement of the movable electrode 230.

[0041] In this embodiment, the electrode assembly 320 is fixed to the surface of the substrate 310, forming an electrode pair with the movable electrode 230 in the impact floating mechanism 200. The electrode assembly 320 and the movable electrode 230 cooperate to form a capacitor. When the movable electrode 230 is displaced due to an impact, the capacitance value between the electrode pairs changes with the change in the distance between the plates or the overlapping area. By detecting this change in capacitance, the intensity and direction of the impact can be calculated in reverse. On the other hand, the centerline of the electrode assembly 320 coincides with the centerline of the movable electrode 230, providing a precise reference axis for the displacement of the movable electrode 230, ensuring that the displacement of the movable electrode 230 is always within the effective detection range, and avoiding distortion of the detection signal due to displacement deviation.

[0042] Furthermore, the electrode assembly 320 includes an annular positive electrode 321 and an annular negative electrode 322, which are alternately arranged in the direction extending outward from the center of the electrode assembly 320 to its edge. The annular positive electrode 321 and the annular negative electrode 322 are concentrically distributed with the center line of the electrode assembly 320 as the center, and are alternately arranged in the radial direction extending from the center of the electrode assembly 320 to its edge, thereby achieving the purpose of improving detection accuracy and signal stability. On the one hand, the concentric ring structure is compatible with the outer circumference of the movable electrode 230. When the movable electrode 230 undergoes radial or axial displacement due to impact, it ensures that the overlapping area or electrode spacing between the movable electrode 230 and the positive and negative electrodes changes uniformly, avoiding sudden changes in local capacitance caused by irregular electrode shape. This makes the capacitance change and displacement linearly correlated, thereby improving the accuracy of impact strength and direction detection. On the other hand, the alternating distribution of positive and negative electrodes can increase the number of electrode pairs within the limited area of ​​the substrate 310, enhance the output strength of the electrical signal, and reduce the influence of external interference on the detection signal. At the same time, when the movable electrode 230 undergoes a small displacement, multiple alternating electrode pairs can synchronously capture the capacitance change, further improving the detection sensitivity of the sensor and ensuring that even a weak impact can be accurately detected.

[0043] Specifically, the electrode assembly 320 further includes a positive electrode pad 323 and a negative electrode pad 324 disposed on the substrate 310. One end of the annular positive electrode 321 is disposed corresponding to the movable electrode 230, and the other end extends to the edge of the substrate 310 and is connected to the positive electrode pad 323. One end of the annular negative electrode 322 is disposed corresponding to the movable electrode 230, and the other end extends to the edge of the substrate 310 and is connected to the negative electrode pad 324.

[0044] Both the positive electrode pad 323 and the negative electrode pad 324 are fixedly disposed on the surface of the substrate 310 and located close to the edge of the substrate 310. One end of the annular positive electrode 321 faces the movable electrode 230, forming a capacitance detection structure with the movable electrode 230. The other end extends to the edge of the substrate 310 through conductive lines on the surface of the substrate 310, ultimately achieving a stable electrical connection with the positive electrode pad 323. Similarly, one end of the annular negative electrode 322 is positioned corresponding to the movable electrode 230, participating in capacitance detection. The other end also extends to the edge of the substrate 310, forming a reliable electrical connection with the negative electrode pad 324. This structural design enables the construction of a complete signal detection and transmission path. Furthermore, the positive electrode pad 323 and the negative electrode pad 324 serve as connection endpoints for external circuits. The electrode assembly 320 can be connected to the external system via wires, probes, etc. This solves the problem of messy and easily broken wiring when the ring electrode is directly connected to the external circuit, providing a stable interface for electrical signal transmission. At the same time, the ring positive electrode 321 is connected to the positive electrode pad 323, and the ring negative electrode 322 is connected to the negative electrode pad 324. This ensures that the detected capacitance change signal is transmitted to the external circuit accurately and without confusion, avoiding detection errors caused by cross-interference between positive and negative signals. It also facilitates subsequent processing such as amplification, filtering, and conversion of the electrical signal.

[0045] Example 2:

[0046] This embodiment provides a sensing device, which includes the helical beam MEMS impact sensor described in Embodiment 1.

[0047] In summary, compared with existing conventional impact sensors, the spiral beam MEMS impact sensor and sensing device described in this utility model have significant improvements in elastic deformation capability, fatigue resistance, service life, structural sealing, anti-interference capability, detection accuracy and sensitivity, manufacturing convenience, cost control and miniaturization adaptability, and have a wider range of applications, giving them significant advantages in this industry.

[0048] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A helical beam MEMS impact sensor, characterized in that: include: A support mechanism, comprising a substrate and an electrode assembly, wherein the electrode assembly is disposed on the substrate; An impact floating mechanism is provided, comprising a bonding frame, at least one helical beam, and a movable electrode. The bonding frame is disposed on the substrate and bonded to the side of the substrate where the electrode assembly is located. One end of the helical beam is connected to the inner wall of the bonding frame, and the other end is connected to the movable electrode. The main body of the helical beam is arranged in a helical structure around the outer periphery of the movable electrode. The movable electrode is clearance-fitted with the electrode assembly, and the centerline of the movable electrode coincides with the centerline of the electrode assembly. The cover plate and the support mechanism are respectively disposed on opposite sides of the impact floating mechanism in the thickness direction, and the cover plate is bonded to the bonding frame.

2. The helical beam MEMS impact sensor according to claim 1, characterized in that: The impact floating mechanism includes multiple spiral beams, which are evenly spaced around the outer surface of the moving electrode.

3. The helical beam MEMS impact sensor according to claim 1, characterized in that: The impact floating mechanism also includes multiple limiting posts, which are arranged around the outer surface of the movable electrode, and both ends of any one of the limiting posts are respectively connected to the substrate and the cover plate.

4. The helical beam MEMS impact sensor according to claim 3, characterized in that: The movable electrode is provided with multiple limiting grooves, which are recessed inward from the outer surface of the movable electrode, and multiple limiting posts are embedded in the multiple limiting grooves one by one.

5. The helical beam MEMS impact sensor according to claim 1, characterized in that: The cover plate is provided with a first movable groove, which is recessed inward from the side of the cover plate facing the impact floating mechanism to avoid the moving electrode.

6. The helical beam MEMS impact sensor according to claim 1, characterized in that: The substrate has a protrusion that surrounds the edge of the substrate and protrudes toward the impact floating mechanism. The protrusion is bonded to the bonding frame and forms a second movable groove to avoid the moving electrode.

7. The helical beam MEMS impact sensor according to claim 1, characterized in that: The electrode assembly includes a ring-shaped positive electrode and a ring-shaped negative electrode, which are alternately arranged in a direction extending outward from the center of the electrode assembly to its edge.

8. The helical beam MEMS impact sensor according to claim 7, characterized in that: The electrode assembly further includes a positive electrode pad and a negative electrode pad disposed on the substrate. One end of the annular positive electrode is disposed corresponding to the movable electrode, and the other end extends to the edge of the substrate and is connected to the positive electrode pad. One end of the annular negative electrode is disposed corresponding to the movable electrode, and the other end extends to the edge of the substrate and is connected to the negative electrode pad.

9. The helical beam MEMS impact sensor according to claim 1, characterized in that: The cover plate has a thickness of 380~420μm, the bonding frame has a thickness of 280~320μm, and the substrate has a thickness of 380~420μm, which is the same as the cover plate thickness.

10. A sensing device, characterized in that: Including the helical beam MEMS impact sensor as described in any one of claims 1 to 9.

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