Acceleration sensor and electronic device

Abstract

The application discloses an acceleration sensor and an electronic device, wherein the acceleration sensor comprises a mass block and a fixed electrode. The mass block comprises a mass block main body and a plurality of movable comb tooth electrodes, and the movable comb tooth electrodes are distributed on both sides of an anchor piece; both sides of the anchor piece are provided with detection areas; the fixed electrode comprises a plurality of fixed comb tooth electrodes, and the fixed comb tooth electrodes are distributed on both sides of the anchor piece; the movable comb tooth electrodes and the fixed comb tooth electrodes located on the same side are alternately arranged along a second direction; adjacent movable comb tooth electrodes and fixed comb tooth electrodes jointly form a group of detection capacitors; differential output is performed between two detection areas on the same side of the anchor piece, differential output is performed between two detection areas oppositely arranged in a first direction, and the first direction and the second direction intersect. The application can effectively suppress zero point drift caused by deformation in the direction perpendicular to the substrate, and improve the stability and reliability of the acceleration sensor.

Description

Technical Field

[0001] This application relates to the field of sensor technology, and more particularly to an acceleration sensor and electronic device. Background Technology

[0002] With the rapid development of MEMS (Micro-Electro-Mechanical System) technology, accelerometers manufactured using MEMS processes are widely used in consumer electronics, automotive electronics, industrial control, and other fields. These sensors typically employ a capacitive sensing principle, measuring acceleration by detecting changes in capacitance caused by the displacement of a mass under external acceleration.

[0003] Existing capacitive accelerometers typically consist of a capacitance detection unit comprised of fixed and movable electrodes. In practical applications, when a capacitive accelerometer deforms in a direction perpendicular to the chip substrate, the area of ​​the opposing detection electrodes changes, potentially disrupting the signal matching relationship and causing abnormal output, thus affecting the reliability and stability of the accelerometer's detection. Utility Model Content

[0004] This application provides an acceleration sensor and an electronic device that improves the reliability and stability of the acceleration sensor, thereby at least partially solving the above-mentioned technical problems.

[0005] To achieve the above objectives, according to a first aspect of this application, an acceleration sensor is provided, comprising: A mass block is connected to a substrate via an anchor point. The mass block includes a mass block body and a plurality of movable comb-tooth electrodes extending from the mass block body. A portion of the plurality of movable comb-tooth electrodes is located on one side of the anchor point in a first direction, and another portion is located on the other side of the anchor point in the first direction. The movable comb-tooth electrodes located on the same side of the anchor point are arranged at intervals along a second direction. In the first direction, detection areas are provided on both sides of the anchor point. The detection areas include a first detection area, a second detection area, a third detection area, and a fourth detection area. The first detection area and the third detection area are arranged opposite to each other in the first direction, and the second detection area and the fourth detection area are arranged opposite to each other in the first direction. The fixed electrode includes a plurality of fixed comb-tooth electrodes. A portion of the plurality of fixed comb-tooth electrodes is located on one side of the anchor member in the first direction, and another portion is located on the other side of the anchor member in the first direction. The movable comb-tooth electrodes and the fixed comb-tooth electrodes located on the same side of the anchor member are alternately arranged along the second direction. Adjacent movable comb-tooth electrodes and fixed comb-tooth electrodes together form a set of detection capacitors. At least one set of detection capacitors is provided in each detection area. When the movable comb electrode is displaced in the second direction, differential output is generated between two detection areas on the same side of the anchor point, and differential output is generated between two detection areas opposite each other in the first direction, wherein the first direction and the second direction intersect.

[0006] Optionally, the fixed electrode further includes multiple fixing parts, with the fixed comb electrode located in the same detection area connected to the same fixing part, and the fixed comb electrode located in different detection areas connected to different fixing parts.

[0007] Optionally, the fixing portions of the first detection area and the second detection area are arranged at intervals along the second direction, the fixing portions of the third detection area and the fourth detection area are arranged at intervals along the second direction, and the fixing portions of the detection areas that are opposite to each other with respect to the first direction are arranged on both sides of the anchor point.

[0008] Optionally, the acceleration sensor further includes: a first lead portion, wherein the first lead portion, the fixed electrode, and the mass block are located in the same layer, one end of the first lead portion is electrically connected to the fixed portion of the second detection area, and the other end is electrically connected to the fixed portion of the third detection area.

[0009] Optionally, the anchor point component includes a first anchor point and a second anchor point spaced apart along the second direction; the first lead wire portion passes through a first gap formed between the first anchor point and the second anchor point and connects to a fixing portion of the second detection area and the third detection area.

[0010] Optionally, it also includes: Substrate; An electrical connection portion is located on the substrate, and the mass block and the fixed electrode are both located on the side of the electrical connection portion away from the substrate. Each fixed portion is electrically connected to one of the electrical connection portions. The second lead portion is located in the same layer as the electrical connection portion. One end of the second lead portion is electrically connected to the electrical connection portion located in the first detection area, and the other end is electrically connected to the electrical connection portion located in the fourth detection area.

[0011] Optionally, the anchor point includes a first anchor point and a second anchor point spaced apart along the second direction. The first anchor point and the second anchor point are electrically connected to different electrical connection portions, and a second gap is formed between the electrical connection portions connecting the first anchor point and the second anchor point. The second lead portion passes through the second gap and connects the electrical connection portion located in the first detection area and the electrical connection portion located in the fourth detection area.

[0012] Optionally, in a direction perpendicular to the substrate, the first lead portion is suspended across the second gap and connects the fixing portion of the second detection area and the fixing portion of the third detection area.

[0013] Optionally, the fixed comb electrode located between two movable comb electrodes has a first side and a second side in the second direction; in the first detection area and the fourth detection area, the distance between the fixed comb electrode and an adjacent movable comb electrode on the first side is greater than the distance between the fixed comb electrode and another adjacent movable comb electrode on the second side; in the second detection area and the third detection area, the distance between the fixed comb electrode and an adjacent movable comb electrode on the first side is less than the distance between the fixed comb electrode and another adjacent movable comb electrode on the second side.

[0014] According to a second aspect of this application, an electronic device is provided, comprising the acceleration sensor described in any one of the foregoing claims.

[0015] In this application, a first detection area, a second detection area, a third detection area, and a fourth detection area are provided on both sides of the anchor point. The first and third detection areas, as well as the second and fourth detection areas, are positioned opposite each other with respect to a first direction, allowing differential output between detection areas on the same side and between detection areas on opposite sides. This enables the detection capacitors, which exhibit "unidirectional change," to be distributed across both sides of the anchor point, rather than concentrated on the same side. When one side of the anchor point deforms in a direction perpendicular to the substrate, the detection capacitors located in the first and second detection areas on that side exhibit approximately identical common-mode capacitance changes under the deformation in the direction perpendicular to the substrate. Similarly, the detection capacitors located in the third and fourth detection areas on the other side also exhibit approximately identical common-mode capacitance changes. Based on this, when differential operations are performed between detection areas on the same side and between detection areas positioned opposite each other in the first direction, the common-mode capacitance component introduced by deformation in the direction perpendicular to the substrate can be canceled out in the differential channel, retaining only the differential component related to the acceleration in the sensitive direction. Therefore, it can effectively suppress zero-point drift caused by deformation in the direction perpendicular to the substrate, maintain the symmetry and stability of the differential output, and thus improve the stability and reliability of the accelerometer.

[0016] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description 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.

[0017] 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.

[0018] Figure 1 This is a schematic diagram of the structure of an acceleration sensor disclosed in an embodiment of this application; Figure 2 This is a schematic diagram of the structure of a substrate disclosed in an embodiment of this application; Figure 3 This is a cross-sectional schematic diagram of an acceleration sensor disclosed in an embodiment of this application.

[0019] Explanation of reference numerals in the attached figures: 1. Mass block; 11. Anchor point component; 111. First anchor point; 112. Second anchor point; 113. First gap; 12. Movable comb tooth electrode; 13. Mass block body; 2. Fixed electrode; 21. Fixed comb tooth electrode; 22. Fixing part; 3. Testing Area; 31. First Testing Area; 32. Second Testing Area; 33. Third Testing Area; 34. Fourth Testing Area; 4. First lead section; 5. Substrate; 6. Electrical connection part; 61. Second gap; 8. Second lead section; 9. Border; 91. Flexible limiting component; 92. Limiting protrusions 10. Anchor block. Detailed Implementation

[0020] 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.

[0021] As described in the background section, existing capacitive accelerometers generally include a capacitance detection unit consisting of a fixed electrode and a movable electrode. Under normal operating conditions, when the mass block is displaced along the acceleration-sensitive axis, the distance between the fixed electrode and the movable electrode changes, thereby causing a change in capacitance. External acceleration information can be obtained by detecting the change in capacitance.

[0022] Furthermore, when the accelerometer deforms in the direction perpendicular to the substrate, even if the external acceleration is zero, the relative orientation between the detection electrodes will change, causing the effective facing area of ​​the electrodes to change. This leads to a shift in the initial value of the detection capacitance, disrupting the matching detection signal relationship and causing abnormal detection output, thus affecting the reliability and stability of the accelerometer's detection results.

[0023] Specifically, in some embodiments, the accelerometer includes at least two sets of detection capacitors, each set comprising multiple capacitors. One set of capacitors increases simultaneously under external acceleration, while the other set decreases simultaneously. In this embodiment, the capacitors in the "co-directional" set are arranged on the same side of the mass block. When that side of the chip deforms in a direction perpendicular to the substrate, the area of ​​the detection electrodes on that side decreases or increases synchronously, causing an overall shift in the initial capacitance of this set of capacitors and its capacitance change under acceleration. At this point, the capacitance value and capacitance change of this set of capacitors cannot be precisely matched with the capacitors arranged on the other side, causing the differential detection to lose its intended symmetry and complementarity. On the one hand, under zero external acceleration, the differential output is no longer the predetermined zero value, but exhibits a DC offset, i.e., zero-point drift.

[0024] To improve the reliability and stability of accelerometers, this application discloses an accelerometer.

[0025] Reference Figure 1 The accelerometer disclosed in this application includes a mass block 1 and a fixed electrode 2. The mass block 1 is connected to a substrate 5 via an anchor point 11. The mass block 1 includes a mass block body 13 and a plurality of movable comb-tooth electrodes 12 extending from the mass block body 13. A portion of the plurality of movable comb-tooth electrodes 12 is located on one side of the anchor point 11 in a first direction, and another portion is located on the other side of the anchor point 11 in the first direction. The movable comb-tooth electrodes 12 located on the same side of the anchor point 11 are arranged at intervals along a second direction. The fixed electrode 2 includes a plurality of fixed comb-tooth electrodes 21. A portion of the plurality of fixed comb-tooth electrodes 21 is located on one side of the anchor point 11 in the first direction, and another portion is located on the other side of the anchor point 11 in the first direction. The movable comb-tooth electrodes 12 and fixed comb-tooth electrodes 21 located on the same side of the anchor point 11 are arranged alternately along the second direction. Adjacent movable comb-tooth electrodes 12 and fixed comb-tooth electrodes 21 together form a set of detection capacitors.

[0026] In the first direction, detection areas 3 are provided on both sides of the anchor member 11. Detection areas 3 include a first detection area 31, a second detection area 32, a third detection area 33, and a fourth detection area 34. The first detection area 31 and the third detection area 33 are arranged opposite each other in the first direction, and the second detection area 32 and the fourth detection area 34 are arranged opposite each other in the first direction. Each detection area 3 is provided with at least one set of detection capacitors, that is, each of the first detection area 31, the second detection area 32, the third detection area 33, and the fourth detection area 34 is provided with at least one set of detection capacitors. In other words, each of the first detection area 31, the second detection area 32, the third detection area 33, and the fourth detection area 34 is provided with at least one movable comb electrode 12 and one fixed comb electrode 21. When the movable comb electrode 12 is displaced in the second direction, differential output is generated between the two detection areas 3 on the same side of the anchor member 11 and between the two detection areas 3 arranged opposite each other in the first direction.

[0027] Specifically, continue to refer to Figure 1 In one specific embodiment of this application, each detection area 3 is provided with multiple detection capacitors. A fixed comb electrode 21 located between two movable comb electrodes 12 has a first side and a second side in a second direction. In the first detection area 31 and the fourth detection area 34, the distance between the fixed comb electrode 21 on its first side and an adjacent movable comb electrode 12 is greater than the distance between it on its second side and another adjacent movable comb electrode 12. In the second detection area 32 and the third detection area 33, the distance between the fixed comb electrode 21 on its first side and an adjacent movable comb electrode 12 is less than the distance between it on its second side and another adjacent movable comb electrode 12. In this embodiment, when the movable comb electrode 12 moves along the second direction, the capacitance values ​​of the detection capacitors in the first detection area 31 and the fourth detection area 34 increase, while the capacitance values ​​of the detection capacitors in the second detection area 32 and the third detection area 33 decrease. When the movable comb electrode 12 moves in the opposite direction to the second direction, the capacitance values ​​of the detection capacitors in the first detection area 31 and the fourth detection area 34 decrease, while the capacitance values ​​of the detection capacitors in the second detection area 32 and the third detection area 33 increase. Differential outputs are generated between the first detection area 31 and the second detection area 32, between the first detection area 31 and the third detection area 33, between the third detection area 33 and the fourth detection area 34, and between the second detection area 32 and the fourth detection area 34.

[0028] In the embodiments disclosed in this application, a first detection area 31, a second detection area 32, a third detection area 33, and a fourth detection area 34 are provided on both sides of the anchor point 11. The first detection area 31 and the third detection area 33, as well as the second detection area 32 and the fourth detection area 34, are all arranged opposite each other with respect to a first direction, allowing differential output between detection areas 3 on the same side and also between detection areas 3 on opposite sides. Thus, the detection capacitors that exhibit "unidirectional change" are distributed across both sides of the anchor point 11, rather than being concentrated on the same side. When one side of the anchor 11 deforms in the direction perpendicular to the substrate 5, the detection capacitors located in the first detection area 31 and the second detection area 32 on that side produce approximately consistent common-mode capacitance changes under the deformation in the direction perpendicular to the substrate 5. Similarly, the detection capacitors located in the third detection area 33 and the fourth detection area 34 on the other side also produce approximately consistent common-mode capacitance changes. Based on this, when differential operations are performed between the detection areas 3 on the same side and between the detection areas 3 opposite each other in the first direction, the common-mode capacitance component introduced by the deformation perpendicular to the substrate 5 can be canceled out in the differential channel, retaining only the differential component related to the acceleration in the sensitive direction. Therefore, zero-point drift caused by deformation perpendicular to the substrate 5 can be effectively suppressed, maintaining the symmetry and stability of the differential output, thereby improving the stability and reliability of the accelerometer.

[0029] Furthermore, in some embodiments, the fixed electrode 2 further includes multiple fixing portions 22. Fixed comb electrodes 21 located in the same detection area 3 are connected to the same fixing portion 22, and fixed comb electrodes 21 located in different detection areas 3 are connected to different fixing portions 22. Specifically, refer to... Figure 2 Each of the first detection area 31, the second detection area 32, the third detection area 33, and the fourth detection area 34 is provided with a fixing part 22. The fixed comb electrode 21 located in the first detection area 31 is fixedly connected to the fixed comb electrode 21 located in the second detection area 32, the third detection area 33, and the fourth detection area 34, respectively. In a specific embodiment of this application, the connected fixing part 22 and the fixed comb electrode 21 are integrally formed.

[0030] In the above embodiment, the fixed comb electrode 21 located in the same detection area 3 is connected to the same fixing part 22. Compared with some other embodiments where each comb electrode is configured with an anchor block 10, the present embodiment can significantly reduce the number of anchor points by connecting multiple fixed comb electrodes 21 in the same detection area 3 to the same fixing part 22. This allows the accelerometer to arrange more detection capacitors in the same area, improve the effective detection area and capacitance modulation, and thus improve the detection sensitivity and overall reliability of the accelerometer.

[0031] Furthermore, in some embodiments, the fixing portions 22 of the first detection area 31 and the fixing portions 22 of the second detection area 32 are arranged at intervals along the second direction, the fixing portions 22 of the third detection area 33 and the fixing portions 22 of the fourth detection area 34 are arranged at intervals along the second direction, and each fixing portion 22 of the detection area 3 which is provided opposite to the first direction is arranged on both sides of the anchor member 11.

[0032] In one specific embodiment of this application, the electrical signals of the first detection area 31 and the fourth detection area 34 are drawn from the same side, and the electrical signals of the second detection area 32 and the third detection area 33 are drawn from the same side.

[0033] Specifically, refer to Figure 1 and Figure 2 The accelerometer also includes a first lead portion 4. The first lead portion 4, the fixed electrode 2, and the mass block 1 are located in the same layer. One end of the first lead portion 4 is electrically connected to the fixed portion 22 of the second detection area 32, and the other end is electrically connected to the fixed portion 22 of the third detection area 33. Further, to facilitate the connection of the first lead portion 4 to the fixed portion 22 in the layer containing the fixed electrode 2, the anchor point 11 includes a first anchor point 111 and a second anchor point 112 spaced apart along a second direction. The first lead portion 4 passes through a first gap 113 formed between the first anchor point 111 and the second anchor point 112 to connect the fixed portions 22 of the second detection area 32 and the third detection area 33. In some other embodiments, the connected first lead portion 4 and the fixed portion 22 are integrally formed.

[0034] Furthermore, referring to Figure 2 and Figure 3 The accelerometer also includes a substrate 5 and an electrical connection portion 6. The electrical connection portion 6 is located on the substrate 5, and the mass block 1 and the fixed electrode 2 are both located on the side of the electrical connection portion 6 away from the substrate 5. Each fixed part 22 is electrically connected to one electrical connection portion 6. The second lead portion 8 is located in the same layer as the electrical connection portion 6. One end of the second lead portion 8 is electrically connected to the electrical connection portion 6 located in the first detection area 31, and the other end is electrically connected to the electrical connection portion 6 located in the fourth detection area 34. The first anchor point 111 and the second anchor point 112 are also electrically connected to different electrical connection portions 6.

[0035] In order to facilitate the connection between the second lead portion 8 and the electrical connection portion 6 in the layer where the electrical connection portion 6 is located, a second gap 61 is formed between the electrical connection portions 6 connecting the first anchor point 111 and the second anchor point 112. The second lead portion 8 passes through the second gap 61 to connect the electrical connection portion 6 located in the first detection area 31 and the electrical connection portion 6 located in the fourth detection area 34.

[0036] By cooperating with the first lead portion 4 and the second lead portion 8, the electrical signals of the fixed portions 22 located in the first detection area 31 and the fourth detection area 34 can be collected on one side of the accelerometer and led out from the same side. Similarly, the electrical signals of the fixed portions 22 located in the second detection area 32 and the third detection area 33 can also be collected on one side and led out from the same side. It should be noted that the detection capacitors in the first detection area 31, the second detection area 32, the third detection area 33, and the fourth detection area 34 can be collected and led out from the same side of the accelerometer. This arrangement allows for the effective collection of similar detection electrical signals within each detection area 3 via the lead portions without increasing the accelerometer area. These signals can then be connected to the corresponding pads via the electrical connection portion 6 to complete the electrical connection with external circuits, thereby simplifying the layout and reducing the difficulty of lead routing.

[0037] Furthermore, through the first lead portion 4 and the second lead portion 8, the detection capacitors in the first detection area 31 and the fourth detection area 34 are electrically connected in parallel inside the accelerometer and then led out from the same side. Similarly, the detection capacitors in the second detection area 32 and the third detection area 33 are also electrically connected in parallel inside the accelerometer and then led out from the same side. After the above parallel connection and lead summation, the electrical signal output by the first detection area 31 and the fourth detection area 34 in parallel and the electrical signal output by the second detection area 32 and the third detection area 33 in parallel exhibit characteristics of basically equal amplitude and opposite direction under the action of acceleration. During differential readout, this effectively suppresses common-mode interference introduced by factors such as processing deviation and packaging stress, as well as zero-point drift caused by stress mismatch.

[0038] Simultaneously, the electrical signals from the electrical connection 6 connecting the first anchor point 111 and the electrical connection 6 connecting the second anchor point 112 are led out from both sides of the accelerometer in the second direction. The electrical signals led out from the two electrical connection 6 are equal in magnitude and opposite in direction. However, the interference components introduced by factors such as manufacturing differences, environmental changes, and parasitic capacitance change in basically the same direction on both sides. During subsequent differential readout, the signals on both sides of the corresponding leads are subtracted differentially, so that the interference components in the same direction cancel each other out in the calculation, retaining only the effective signal components that are equal in magnitude and opposite in direction. Thus, the influence of common-mode interference on the output result can be suppressed, and the signal-to-noise ratio and stability of the differential output signal can be improved.

[0039] Furthermore, continue to refer to Figure 3 , Figure 3 This is a cross-sectional schematic diagram of an accelerometer sensor disclosed in an embodiment of this application. Figure 3 It shows Figure 1A cross-sectional view at point A (at the first gap 113 and the second gap 61) perpendicular to the first direction and parallel to the direction perpendicular to the substrate 5. In a specific embodiment of this application, both the fixing part 22 and the anchor point 11 are connected to the electrical connection part 6 via the anchor block 10. At the first gap 113 and the second gap 61, in the direction perpendicular to the substrate 5, the first lead part 4 is suspended across the second gap 61, connecting the fixing part 22 of the first detection area 31 and the fixing part 22 of the fourth detection area 34. In other words, at the first gap 113 and the second gap 61, the first lead part 4 and the second lead part 8 are spaced apart in the direction perpendicular to the substrate 5. The first lead part 4 being suspended across the second gap 61 can effectively reduce the parasitic capacitance between the first lead part 4 and the second lead part 8.

[0040] In some embodiments, the second lead portion 8 has a Z-shaped structure. To reduce the impact of oxide layer release between the layer containing the fixed electrode 2 and the layer containing the substrate 5 on the integrity and electrical performance of the second lead portion 8, in some embodiments the width of the second lead portion 8 is in the range of 20–40 μm. This ensures that the second lead portion 8 still has sufficient conductive cross-sectional area and structural stability after oxide layer release, thereby improving the reliability and manufacturing yield of the accelerometer. After the oxide layer is released between the layer containing the fixed electrode 2 and the layer containing the substrate 5, the aforementioned spacing is formed between the first lead portion 4 and the second lead portion 8.

[0041] It is worth mentioning that, in some embodiments, the mass block body 13 has a through groove that extends through itself, and the anchor point 11, the fixed electrode 2, and the movable comb tooth electrode 12 are all located in the through groove. The first anchor point 111 is elastically connected to the inner wall of one side of the through groove in the second direction, and the second anchor point 112 is elastically connected to the inner wall of the other side of the through groove in the second direction. Each movable comb tooth electrode 12 is elastically connected to the interior of both sides of the through groove in the first direction.

[0042] In some embodiments, the accelerometer further includes a frame 9, on which an elastic limiting member 91 protrudes from the inner wall of the frame 9 facing the mass block 1. A limiting groove is formed on the edge of the mass block body 13 corresponding to the position of the elastic limiting member 91, and the elastic limiting member 91 is located in the limiting groove. In a specific embodiment, both the mass block body 13 and the frame 9 are rectangular frames. The elastic limiting member 91 is distributed on the inner walls of the frame 9 on opposite sides in a first direction, and extends into the limiting groove along the first direction. In some embodiments, a limiting protrusion 92 is also protruding from the inner wall of the frame 9 facing the mass block 1. The limiting protrusion 92 is distributed on the inner walls of the frame 9 on opposite sides in a second direction, and a gap exists between the limiting protrusion 92 and the outer wall of the mass block 1.

[0043] The elastic limiting member 91 is elastic and is a flexible limiting member. When the displacement of the mass block 1 in the second direction exceeds the normal working stroke and approaches the frame 9, the elastic limiting member 91 contacts the frame 9 before the mass block body 13 and undergoes elastic deformation in the limiting groove. Through its elastic restoring force, it exerts a reverse limiting effect on the mass block 1. On the one hand, it can limit the maximum displacement of the mass block 1, preventing the mass block 1 from directly impacting the frame 9 and adhering to it. On the other hand, it can buffer and absorb impact loads, reducing the damage of collision impact to the sensitive structure, thereby improving the reliability and service life of the accelerometer under large impact and over-range conditions. The limiting protrusion 92 can prevent the mass block 1 from moving laterally in the second direction to engage with the frame 9 under abnormal impact conditions.

[0044] This application also discloses an electronic device that includes any of the above-mentioned acceleration sensors.

[0045] 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.

[0046] 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.

[0047] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0048] 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. An acceleration sensor, characterized in that, include: A mass block (1) is connected to a substrate (5) via an anchor point (11). The mass block (1) includes a mass block body (13) and a plurality of movable comb electrodes (12) extending from the mass block body (13). A portion of the plurality of movable comb electrodes (12) is located on one side of the anchor point (11) in a first direction, and another portion is located on the other side of the anchor point (11) in the first direction. Movable comb electrodes (12) located on the same side of the anchor point (11) are arranged at intervals along a second direction. In the first direction, detection areas (3) are provided on both sides of the anchor point (11). The detection areas (3) include a first detection area (31), a second detection area (32), a third detection area (33), and a fourth detection area (34). The first detection area (31) and the third detection area (33) are arranged opposite to each other in the first direction, and the second detection area (32) and the fourth detection area (34) are arranged opposite to each other in the first direction. The fixed electrode (2) includes a plurality of fixed comb teeth electrodes (21). A portion of the plurality of fixed comb teeth electrodes (21) is located on one side of the anchor point (11) in the first direction, and another portion is located on the other side of the anchor point (11) in the first direction. The movable comb teeth electrodes (12) and the fixed comb teeth electrodes (21) located on the same side of the anchor point (11) are arranged alternately along the second direction. The adjacent movable comb teeth electrodes (12) and the fixed comb teeth electrodes (21) together form a set of detection capacitors. At least one set of detection capacitors is provided in each detection area (3). When the movable comb electrode (12) is displaced in the second direction, differential output is generated between the two detection areas (3) on the same side of the anchor point (11), and differential output is generated between the two detection areas (3) opposite to each other in the first direction, and the first direction and the second direction intersect.

2. The acceleration sensor according to claim 1, characterized in that, The fixed electrode (2) also includes multiple fixing parts (22). The fixed comb electrode (21) located in the same detection area (3) is connected to the same fixing part (22), and the fixed comb electrode (21) located in different detection areas (3) is connected to different fixing parts (22).

3. The acceleration sensor according to claim 2, characterized in that, The fixing parts (22) of the first detection area (31) and the fixing parts (22) of the second detection area (32) are arranged at intervals along the second direction. The fixing parts (22) of the third detection area (33) and the fixing parts (22) of the fourth detection area (34) are arranged at intervals along the second direction. Furthermore, the fixing parts (22) of each detection area (3) that is opposite to the first direction are arranged on both sides of the anchor point (11).

4. The acceleration sensor according to claim 2, characterized in that, The acceleration sensor further includes: a first lead part (4), the first lead part (4), the fixed electrode (2), and the mass block (1) are located in the same layer, one end of the first lead part (4) is electrically connected to the fixed part (22) of the second detection area (32), and the other end is electrically connected to the fixed part (22) of the third detection area (33).

5. The accelerometer according to claim 4, characterized in that, The anchor point component (11) includes a first anchor point (111) and a second anchor point (112) spaced apart along the second direction; the first lead wire portion (4) passes through the first gap (113) formed between the first anchor point (111) and the second anchor point (112) and connects the fixing portion (22) of the second detection area (32) and the third detection area (33).

6. The accelerometer according to claim 4, characterized in that, Also includes: Substrate (5); An electrical connection portion (6) is located on the substrate (5). The mass block (1) and the fixed electrode (2) are both located on the side of the electrical connection portion (6) away from the substrate (5). Each fixed part (22) is electrically connected to one of the electrical connection portions (6). The second lead portion (8) is located in the same layer as the electrical connection portion (6). One end of the second lead portion (8) is electrically connected to the electrical connection portion (6) located in the first detection area (31), and the other end is electrically connected to the electrical connection portion (6) located in the fourth detection area (34).

7. The accelerometer according to claim 6, characterized in that, The anchor point component (11) includes a first anchor point (111) and a second anchor point (112) spaced apart along the second direction. The first anchor point (111) and the second anchor point (112) are electrically connected to different electrical connection portions (6), and a second gap (61) is formed between the electrical connection portions (6) connecting the first anchor point (111) and the second anchor point (112). The second lead portion (8) passes through the second gap (61) and connects the electrical connection portion (6) located in the first detection area (31) and the electrical connection portion (6) located in the fourth detection area (34).

8. The accelerometer according to claim 7, characterized in that, In a direction perpendicular to the substrate (5), the first lead portion (4) is suspended across the second gap (61) and connects the fixing portion (22) of the second detection area (32) and the fixing portion (22) of the third detection area (33).

9. The acceleration sensor according to claim 1, characterized in that, The fixed comb electrode (21) located between two movable comb electrodes (12) has a first side and a second side in the second direction; in the first detection area (31) and the fourth detection area (34), the distance between the fixed comb electrode (21) and the adjacent movable comb electrode (12) on the first side is greater than the distance between it and another adjacent movable comb electrode (12) on the second side; in the second detection area (32) and the third detection area (33), the distance between the fixed comb electrode (21) and the adjacent movable comb electrode (12) on the first side is less than the distance between it and another adjacent movable comb electrode (12) on the second side.

10. An electronic device, characterized in that, Includes the acceleration sensor as described in any one of claims 1 to 9.

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