Accelerometer and electronic equipment

Abstract

The invention provides an accelerometer and electronic equipment, relates to the technical field of micro electro mechanical systems, and can reduce the temperature difference influence in the height direction, reduce the temperature drift and improve the detection precision of the accelerometer. The accelerometer includes a substrate layer, a first anchor point, and a first mass plate. The first anchor point is fixed to the substrate layer. The first mass plate is connected to the first anchor point through the first torsion beam, and the parts, located on the two sides of the first torsion beam, of the first mass plate are a first mass part and a second mass part correspondingly. At least one of the first mass part and the second mass part is provided with a through hole, the sum of the areas of the through holes in the first mass part is smaller than the sum of the areas of the through holes in the second mass part, and the outer contour of the first mass part and the outer contour of the second mass part are symmetrically arranged relative to the first torsion beam.

Description

Technical Field

[0001] The present application relates to the technical field of micro-electromechanical systems, and in particular to an accelerometer and an electronic device. Background Art

[0002] Accelerometers are commonly used in consumer electronics (3C) products such as mobile phones, personal computers (PCs), headphones, and wearable devices, as well as in industrial equipment such as automobiles and assembly lines. Accelerometers are used to detect acceleration or are combined with micro-electromechanical system (MEMS) sensors, such as vibration sensors, acceleration sensors, and gyroscopes, to achieve noise reduction or improve reliability. For example, an accelerometer is used as a bone conduction accelerometer to receive bone vibration signals caused by a user's voice. Combined with a microphone, it can remove noise from the microphone's detection signal, thereby achieving the purpose of noise reduction.

[0003] Currently, the internal mechanical structure of an accelerometer can adopt a seesaw structure. For example, the seesaw structure can include a mass plate, an anchor point, a torsion beam, and detection electrodes. The mass plate is connected to the anchor point via a torsion beam. The portions of the mass plate located on either side of the torsion beam are arranged asymmetrically, and the detection electrodes are located above or below the portions of the mass plate on either side of the torsion beam. In this way, under the influence of acceleration, the mass plate will drive the torsion beam to rotate around the axis formed by the torsion beam and the anchor point, thereby changing the capacitance between the portions of the mass plate on either side of the torsion beam and the detection electrodes. By detecting this capacitance change, a change in the detection signal can be obtained.

[0004] However, when a temperature difference occurs in the height direction of the seesaw structure, the gas expansion or contraction exerts different thrusts or suctions on some mass plates on both sides of the torsion beam, which causes the detection results to be affected by temperature drift and affects the detection accuracy. Summary of the Invention

[0005] The present application provides an accelerometer and an electronic device, which can reduce the influence of temperature differences in the height direction, reduce temperature drift, and improve the detection accuracy of the accelerometer.

[0006] To achieve the above objectives, the embodiments of the present application adopt the following technical solutions:

[0007] In a first aspect, an accelerometer is provided, comprising a base layer, a first anchor point, and a first mass plate. The first anchor point is fixed to the base layer. The first mass plate is connected to the first anchor point via a first torsion beam, and the portions of the first mass plate located on either side of the first torsion beam are a first mass portion and a second mass portion, respectively. At least one of the first mass portion and the second mass portion has a through hole, and the sum of the areas of the through holes in the first mass portion is smaller than the sum of the areas of the through holes in the second mass portion. The outer contours of the first mass portion and the second mass portion are symmetrically arranged about the first torsion beam.

[0008] In this way, the sum of the setting areas of the through holes on the first mass part is designed to be unequal to the sum of the setting areas of the through holes on the second mass part, so that the masses of the first mass part and the second mass part can be asymmetric, so as to form a seesaw structure, which can realize the detection of the bone vibration signal component in the Z-axis direction, and the Z-axis direction is the direction perpendicular to the base layer. At the same time, because the outer contours of the first mass portion and the second mass portion are symmetrically arranged about the first torsion beam, the outer contour of the first mass portion is defined as the first outer contour, and the outer contour of the second mass portion is defined as the second outer contour. The area enclosed by the first outer contour is equal to the area enclosed by the second outer contour, and the geometric center of the area enclosed by the first outer contour is symmetrical to the geometric center of the area enclosed by the second outer contour about the first torsion beam. Therefore, when a temperature gradient exists in the accelerometer in the Z-axis direction, the gas between the first mass plate and the base layer expands, which can push the mass portions of approximately equal area on both sides of the first torsion beam (that is, the first mass portion and the second mass portion), and generate approximately equal torque on the two mass portions, thereby achieving a substantial balance and preventing the first mass plate from experiencing seesaw-like motion. Thus, temperature drift of the accelerometer in the Z-axis direction can be reduced or eliminated.

[0009] Optionally, the accelerometer may further include a first Z-axis detection electrode and a second Z-axis detection electrode. The first Z-axis detection electrode and the second Z-axis detection electrode are disposed on the base layer, and along the Z-axis direction, the first Z-axis detection electrode is opposite to at least a portion of the first mass portion, and the second Z-axis detection electrode is opposite to at least a portion of the second mass portion. In this way, when the bone vibration signal component in the Z-axis direction is input into the accelerometer, the first mass plate will produce a seesaw-like motion, causing the distance between the first Z-axis detection electrode and the first mass portion, and between the second Z-axis detection electrode and the second mass portion to change, thereby converting the bone vibration signal component in the Z-axis direction into an electrical signal reflecting the capacitance change between the first Z-axis detection electrode and the first mass portion, and between the second Z-axis detection electrode and the second mass portion, thereby achieving detection of the vibration signal.

[0010] Optionally, there are multiple through holes, and the multiple through holes form two groups of through holes, and the two groups of through holes are respectively the first group of through holes and the second group of through holes. The first group of through holes is arranged in the first mass part, and the second group of through holes is arranged in the second mass part. The vertical projection area of ​​each through hole in the first group of through holes on the base layer is equal to the vertical projection area of ​​each through hole in the second group of through holes on the base layer, and the number of through holes in the first group of through holes is less than the number of through holes in the second group of through holes. As a result, the sum of the setting areas of the through holes on the first mass part is smaller than the sum of the setting areas of the through holes on the second mass part. In this way, the structural design is simple and easy to implement

[0011] Optionally, the first mass section includes a first mass subsection and a second mass subsection. Along the Z-axis, a first Z-axis detection electrode opposes the first mass subsection, and a first group of through-holes is provided in the second mass subsection. The second mass section includes a third mass subsection and a fourth mass subsection. Along the Z-axis, the second Z-axis detection electrode opposes the third mass subsection, and a second group of through-holes is provided in the fourth mass subsection. In this manner, the through-holes on the first mass section and the first Z-axis detection electrode, as well as the through-holes on the second mass section and the second Z-axis detection electrode, are staggered. The through-holes on the first mass section and the through-holes on the second mass section can function as comb holes to accommodate comb teeth for detecting signals in other directions.

[0012] Optionally, the first mass subsection is located on the side of the second mass subsection facing away from the first torsion beam, and the third mass subsection is located on the side of the fourth mass subsection facing away from the first torsion beam. In this way, the first and third mass subsections are positioned away from the first torsion beam. When the first mass plate generates a seesaw-like motion and rotates at a constant angle, the distance between the first mass subsection and the first Z-axis detection electrode, as well as the distance between the third mass subsection and the second Z-axis detection electrode, significantly changes, leading to a significant change in capacitance, which can improve detection sensitivity and accuracy.

[0013] Optionally, the accelerometer further includes a Y-axis detection electrode and a comb assembly. The Y-axis detection electrode is disposed on the base layer. The comb assembly includes fixed teeth and movable teeth. The fixed teeth are fixed to the base layer and electrically conductive with the Y-axis detection electrode. The ends of the fixed teeth facing away from the base layer are accommodated in the through-holes. The movable teeth are disposed on the first mass plate. The fixed teeth and the movable teeth are spaced apart along the Y-axis, where the Y-axis is parallel to the base layer and perpendicular to the first torsion beam. When the accelerometer senses a bone vibration signal component input in the Y-axis direction, the first mass plate drives the movable teeth to move relative to the fixed teeth in the Y-axis direction, thereby causing a change in capacitance between the Y-axis detection electrode and the first mass plate. The Y-axis detection electrode detects the change in distance from the first mass plate, thereby converting the bone vibration signal component in the Y-axis direction into an electrical signal reflecting the change in capacitance between the first mass plate and the Y-axis detection electrode. In this way, the first mass plate is used to detect bone vibration signal components in the Y-axis direction in addition to detecting bone vibration signal components in the Z-axis direction. That is, the first mass plate serves as both the Z-axis mass plate and the Y-axis mass plate, thereby forming a dual-axis shared mass plate structure, which can increase detection sensitivity.

[0014] Optionally, the accelerometer further includes a first elastic member. The first elastic member is located on the side of the first mass portion facing away from the second mass portion, with one end of the first elastic member connected to the first mass portion and the other end fixed relative to the base layer. The first elastic member can prevent the first mass portion from twisting in the plane, thereby increasing the in-plane torsional stiffness of the first mass portion. Moreover, the first elastic member and the first mass plate are arranged side by side in the XY plane to avoid thickness overlap, which is conducive to thinning the thickness of the chip body.

[0015] Optionally, the accelerometer further includes a first fixing portion and a second fixing portion. The first fixing portion is disposed at the end of the first mass portion facing away from the second mass portion, and the second fixing portion is located on the side of the first fixing portion facing away from the first mass portion. The second fixing portion is fixed relative to the base layer, and the first elastic member is connected between the first and second fixing portions. The first fixing portion prevents positional interference between the first elastic member and the first mass portion during relative motion. The second fixing portion provides the first elastic member with room for deformation in the Z direction.

[0016] Optionally, the first elastic member includes at least one elastic arm. Each elastic arm includes multiple first elastic arm segments and at least one second elastic arm segment. Each first elastic arm segment extends along the length direction of the first torsion beam, and multiple first elastic arm segments are arranged along the Y-axis direction, with a gap between two adjacent first elastic arm segments. Multiple first elastic arm segments are alternately connected to at least one second elastic arm segment in sequence. In this way, the elastic arm is roughly a planar spring structure, which is conducive to the thinning of the chip body. In addition, the first elastic member has little effect on the seesaw motion stiffness of the first mass plate. At the same time, the first elastic member has little effect on the motion stiffness of the first mass plate 1A along the Y-axis direction.

[0017] Optionally, in two adjacent first elastic arm sections, the two ends of one first elastic arm section are respectively the first end and the second end, and the two ends of the other first elastic arm section are respectively the third end and the fourth end. The direction in which the first end points to the second end is the same as the direction in which the third end points to the fourth end. The second elastic arm section between the two adjacent first elastic arm sections is connected between the second end and the fourth end. In this way, under the premise that the number of the first elastic arm section and the second elastic arm section and the spacing between the two adjacent first elastic arm sections are certain, the compression deformation of the elastic arm along the Y-axis direction is allowed to be larger, which can adapt to the detection of bone vibration signals with a larger amplitude in the Y-axis direction. Under the premise that the designed compression deformation of the elastic arm along the Y-axis direction and the spacing between the two adjacent first elastic arm sections are certain, the number of the first elastic arm section and the second elastic arm section can be reduced to reduce the length of the elastic arm in the Y-axis direction, thereby reducing the volume of the first elastic member and even the chip body.

[0018] Optionally, of two adjacent first elastic arm segments, one first elastic arm segment has a first end and a second end, respectively, while the other first elastic arm segment has a third end and a fourth end, respectively. The direction from the first end to the second end is the same as the direction from the third end to the fourth end. A second elastic arm segment between two adjacent first elastic arm segments is connected between the second and third ends. This allows the second elastic arm segment to be longer, generating a greater Z-axis bending deformation and reducing the effect of the elastic arm on the seesaw-like motion stiffness of the first mass plate.

[0019] Optionally, there are two elastic arms, one on either side of the first axis and symmetrically arranged about the first axis. The first axis is parallel to the first mass plate, passes through the midpoint of the lengthwise direction of the first torsion beam, and is perpendicular to the lengthwise direction of the first torsion beam. The two elastic arms generate a significant elastic force, effectively preventing further in-plane twisting of the first mass portion.

[0020] Optionally, the width of the first elastic arm section is less than or equal to the width of the first torsion beam. In this way, the first elastic arm section has a lower stiffness and is easier to bend, which can further reduce the effect of the elastic arm on the seesaw motion stiffness and Y-axis motion stiffness of the first mass plate.

[0021] Optionally, the gap width between two adjacent first elastic arm segments is 2-5 times the width of the first elastic arm segment. This allows the elastic arm to undergo a greater amount of compressive deformation along the Y-axis, thereby accommodating the detection of bone vibration signals with a relatively large amplitude in the Y-axis direction. Assuming the elastic arm has a certain designed compressive deformation along the Y-axis, the number of first and second elastic arm segments can be reduced to reduce the size of the elastic arm in the Y-axis direction, thereby reducing the size of the first elastic member.

[0022] Optionally, the dimension of the first elastic member along the length of the first torsion beam is less than or equal to the dimension of the first mass plate along the length of the first torsion beam. This allows the first elastic member to provide cushioning and vibration reduction for the first mass plate over a wide range along the length of the first torsion beam, minimizing the risk of damage to the side frame or the retaining structure from the first mass plate during in-plane torsion. This also minimizes the impact of the first mass plate on the side frame or the retaining structure. Furthermore, the width of the first sensitive component in the first direction is not affected.

[0023] Optionally, the base layer has a first surface facing the mass plate and a second surface facing away from the mass plate. The base layer is provided with at least one damping groove recessed from the first surface toward the second surface, with the vertical projections of the first and second groups of through holes on the base layer located within the at least one damping groove. The damping groove reduces squeeze-film damping of the first mass plate, improving the signal-to-noise ratio and, to a certain extent, minimizing temperature drift in the Z-axis direction.

[0024] Optionally, the at least one damping groove includes a first damping groove and a second damping groove. The vertical projection of the first set of through holes on the base layer is located within the first damping groove, and the vertical projection of the second set of through holes on the base layer is located within the second damping groove. In this way, the area of ​​the damping groove provided on the base layer is relatively small, which helps ensure the structural strength of the base layer and, therefore, the chip body.

[0025] Optionally, the number of the at least one damping groove is one, and the vertical projections of the first group of through holes and the second group of through holes on the base layer are both located in the damping groove. In this way, the base layer has a simple shape and is easy to process.

[0026] Optionally, the depth of the damping groove is greater than or equal to 1 μm and less than or equal to 3 μm. In this way, the depth of the damping groove is moderate, which can take into account both the signal-to-noise ratio and the structural strength of the base layer.

[0027] Optionally, the accelerometer further includes a second anchor point and a second mass plate. The second anchor point is fixed to the base layer. The second mass plate is connected to the second anchor point via a second torsion beam, and the portions of the second mass plate located on either side of the second torsion beam constitute a third mass portion and a fourth mass portion, respectively. At least one of the third and fourth mass portions is provided with a through hole, and the sum of the areas of the through holes in the third mass portion is less than the sum of the areas of the through holes in the fourth mass portion. The outer contours of the third and fourth mass portions are symmetrically arranged about the second torsion beam. The second mass plate and the first mass plate are arranged along the length of the first torsion beam, with the length of the second torsion beam parallel to that of the first torsion beam. This ensures that the second sensitive component has the same structural form as the first sensitive component, which can also reduce the impact of temperature differences in the height direction, minimize temperature drift, and improve the detection accuracy of the accelerometer. Furthermore, by providing two sensitive components, each sharing the same mass plate for both the Z-axis and Y-axis directions, the detection sensitivity of the bone vibration signal components in the Z-axis and Y-axis directions can be improved. Furthermore, while maintaining the chip's dimensions, the inclusion of two sensitive components reduces the area of ​​the mass plate within a single sensitive component. This reduces the impact of the mass plate on the side frame during in-plane torsion, lowering the risk of damage to the side frame or the retaining structure from impact, thereby improving reliability. Because the mass plate within a single sensitive component is smaller in area and mass, it has a higher natural frequency and can pick up high-frequency vibration signals, thus ensuring bandwidth.

[0028] Optionally, the direction in which the first mass portion points to the second mass portion is opposite to the direction in which the third mass portion points to the fourth mass portion. In this way, the two mass plates are placed in opposite directions, which can suppress temperature drift along the Y-axis.

[0029] In a second aspect, an accelerometer is provided, comprising a base layer, a first anchor point, a first mass plate, and a first elastic member. The first anchor point is fixed to the base layer. The first mass plate is connected to the first anchor point by means of a first torsion beam, and the portions of the first mass plate located on either side of the first torsion beam are the first mass portion and the second mass portion, respectively. The first elastic member is located on the side of the first mass portion facing away from the second mass portion, and one end of the first elastic member is connected to the first mass portion, while the other end is fixed relative to the base layer. The first elastic member can prevent the first mass portion from twisting in a plane, thereby increasing the in-plane torsional stiffness of the first mass portion. Moreover, the first elastic member and the first mass plate are arranged side by side in the XY plane, which can avoid thickness overlap and facilitate thinning of the chip body.

[0030] Optionally, the accelerometer further includes a first fixing portion and a second fixing portion. The first fixing portion is disposed at the end of the first mass portion facing away from the second mass portion, and the second fixing portion is located on the side of the first fixing portion facing away from the first mass portion. The second fixing portion is fixed relative to the base layer, and the first elastic member is connected between the first and second fixing portions. The first fixing portion prevents positional interference between the first elastic member and the first mass portion during relative motion. The second fixing portion provides the first elastic member with room for deformation in the Z direction.

[0031] Optionally, the first elastic member includes at least one elastic arm. Each elastic arm includes multiple first elastic arm segments and at least one second elastic arm segment. Each first elastic arm segment extends along the length direction of the first torsion beam, and multiple first elastic arm segments are arranged along the Y-axis direction, with a gap between two adjacent first elastic arm segments. Multiple first elastic arm segments are alternately connected to at least one second elastic arm segment in sequence. In this way, the elastic arm is roughly a planar spring structure, which is conducive to the thinning of the chip body. In addition, the first elastic member has little effect on the seesaw motion stiffness of the first mass plate. At the same time, the first elastic member has little effect on the motion stiffness of the first mass plate 1A along the Y-axis direction.

[0032] Optionally, in two adjacent first elastic arm sections, the two ends of one first elastic arm section are respectively the first end and the second end, and the two ends of the other first elastic arm section are respectively the third end and the fourth end. The direction in which the first end points to the second end is the same as the direction in which the third end points to the fourth end. The second elastic arm section between the two adjacent first elastic arm sections is connected between the second end and the fourth end. In this way, under the premise that the number of the first elastic arm section and the second elastic arm section and the spacing between the two adjacent first elastic arm sections are certain, the compression deformation of the elastic arm along the Y-axis direction is allowed to be larger, which can adapt to the detection of bone vibration signals with a larger amplitude in the Y-axis direction. Under the premise that the designed compression deformation of the elastic arm along the Y-axis direction and the spacing between the two adjacent first elastic arm sections are certain, the number of the first elastic arm section and the second elastic arm section can be reduced to reduce the length of the elastic arm in the Y-axis direction, thereby reducing the volume of the first elastic member and even the chip body.

[0033] Optionally, of two adjacent first elastic arm segments, one first elastic arm segment has a first end and a second end, respectively, while the other first elastic arm segment has a third end and a fourth end, respectively. The direction from the first end to the second end is the same as the direction from the third end to the fourth end. A second elastic arm segment between two adjacent first elastic arm segments is connected between the second and third ends. This allows the second elastic arm segment to be longer, generating a greater Z-axis bending deformation and reducing the effect of the elastic arm on the seesaw-like motion stiffness of the first mass plate.

[0034] Optionally, there are two elastic arms, one on either side of the first axis and symmetrically arranged about the first axis. The first axis is parallel to the first mass plate, passes through the midpoint of the lengthwise direction of the first torsion beam, and is perpendicular to the lengthwise direction of the first torsion beam. The two elastic arms generate a significant elastic force, effectively preventing further in-plane twisting of the first mass portion.

[0035] Optionally, the width of the first elastic arm section is less than or equal to the width of the first torsion beam. In this way, the first elastic arm section has a lower stiffness and is easier to bend, which can further reduce the effect of the elastic arm on the seesaw motion stiffness and Y-axis motion stiffness of the first mass plate.

[0036] Optionally, the gap width between two adjacent first elastic arm segments is 2-5 times the width of the first elastic arm segment. This allows the elastic arm to undergo a greater amount of compressive deformation along the Y-axis, thereby accommodating the detection of bone vibration signals with a relatively large amplitude in the Y-axis direction. Assuming the elastic arm has a certain designed compressive deformation along the Y-axis, the number of first and second elastic arm segments can be reduced to reduce the size of the elastic arm in the Y-axis direction, thereby reducing the size of the first elastic member.

[0037] Optionally, the dimension of the first elastic member along the length of the first torsion beam is less than or equal to the dimension of the first mass plate along the length of the first torsion beam. This allows the first elastic member to provide cushioning and vibration reduction for the first mass plate over a wide range along the length of the first torsion beam, minimizing the risk of damage to the side frame or the retaining structure from the first mass plate during in-plane torsion. This also minimizes the impact of the first mass plate on the side frame or the retaining structure. Furthermore, the width of the first sensitive component in the first direction is not affected.

[0038] Optionally, the base layer has a first surface facing the mass plate and a second surface facing away from the mass plate. The base layer is provided with at least one damping groove recessed from the first surface toward the second surface, with the vertical projections of the first and second groups of through holes on the base layer located within the at least one damping groove. The damping groove reduces squeeze-film damping of the first mass plate, improving the signal-to-noise ratio and, to a certain extent, minimizing temperature drift in the Z-axis direction.

[0039] Optionally, the at least one damping groove includes a first damping groove and a second damping groove. The vertical projection of the first set of through holes on the base layer is located within the first damping groove, and the vertical projection of the second set of through holes on the base layer is located within the second damping groove. In this way, the area of ​​the damping groove provided on the base layer is relatively small, which helps ensure the structural strength of the base layer and, therefore, the chip body.

[0040] Optionally, the number of the at least one damping groove is one, and the vertical projections of the first group of through holes and the second group of through holes on the base layer are both located in the damping groove. In this way, the base layer has a simple shape and is easy to process.

[0041] Optionally, the depth of the damping groove is greater than or equal to 1 μm and less than or equal to 3 μm. In this way, the depth of the damping groove is moderate, which can take into account both the signal-to-noise ratio and the structural strength of the base layer.

[0042] In a third aspect, an electronic device is provided, comprising a housing and an accelerometer as described in any one of the above technical solutions. The accelerometer is disposed in the housing.

[0043] Since the electronic device provided in the present application includes an accelerometer as described in any of the above technical solutions, both can solve the same technical problem and achieve the same effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A perspective view of an electronic device provided for some embodiments of the present application;

[0045] Figure 2 for Figure 1 A schematic diagram of the exploded structure of the right earphone in the electronic device shown;

[0046] Figure 3 for Figure 2 The schematic diagram of the structure of the right earphone when it is in use;

[0047] Figure 4 A perspective view of an accelerometer provided for some embodiments of the present application;

[0048] Figure 5 for Figure 4 The schematic diagram of the cross-sectional structure of the accelerometer shown along the AA direction;

[0049] Figure 6 A schematic diagram of the cross-sectional structure of a chip body provided in some embodiments of the present application;

[0050] Figure 7 for Figure 6 The chip body is shown as a top view after removing the signal processing components and the top cover;

[0051] Figure 8 for Figure 7 The chip body is shown as a schematic structural diagram after being rotated 90° along direction a1;

[0052] Figure 9 for Figure 8 Schematic diagram of the structure after the mass plate in the chip body rotates in the plane;

[0053] Figure 10 A top view of a chip body provided in some other embodiments of the present application with the signal processing components and the top cover removed;

[0054] Figure 11 for Figure 10 The schematic diagram of the cross-sectional structure of the chip body along the BB direction is shown;

[0055] Figure 12 A schematic diagram of a cross-sectional structure of a chip body provided in some other embodiments of the present application;

[0056] Figure 13 for Figure 12 The chip body is shown as a top view after removing the signal processing components and the top cover;

[0057] Figure 14 A top view of a chip body provided in some other embodiments of the present application with the signal processing components and the top cover removed;

[0058] Figure 15 for Figure 14 A schematic structural diagram of the first elastic member in the chip body is shown;

[0059] Figure 16 A schematic structural diagram of a first elastic member in a chip body provided in yet other embodiments of the present application;

[0060] Figure 17 A schematic structural diagram of a first elastic member in a chip body provided in yet other embodiments of the present application;

[0061] Figure 18 A schematic structural diagram of a first elastic member in a chip body provided in yet other embodiments of the present application;

[0062] Figure 19 Schematic diagram of the displacement field of the first mass plate along the Y-axis at the first moment in a chip body without the first elastic member and in a chip body with the first elastic member;

[0063] Figure 20 A top view of a chip body provided in some other embodiments of the present application with the signal processing components and the top cover removed;

[0064] Figure 21 A schematic diagram of a cross-sectional structure of a chip body provided in some other embodiments of the present application;

[0065] Figure 22 for Figure 21 A top view of a structure of a base layer in the chip body shown;

[0066] Figure 23 for Figure 21 A top view of another structure of the base layer in the chip body;

[0067] Figure 24 A top view of a chip body provided in some other embodiments of the present application with the signal processing components and the top cover removed;

[0068] Figure 25 A top view of a chip body provided in some other embodiments of the present application with the signal processing components and the top cover removed;

[0069] Figure 26 A top view of the chip body after removing the signal processing components and the top cover is provided in some other embodiments of the present application.

[0070] Reference numerals:

[0071] 100. Electronic equipment;

[0072] 100a, left earphone;

[0073] 100b, right earphone;

[0074] 10. Housing; 101. Earbud housing; 101a. First accommodating space; 1011. Front housing; 1012. Back housing; 1013. Sound outlet; 102. Ear handle housing; 1021. Sound pickup hole; 103. Contact sleeve;

[0075] 20. Circuit board;

[0076] 30. Sound-generating device;

[0077] 40. Microphone;

[0078] 50, accelerometer; 501, packaging substrate; 503, packaging material; 504, pin;

[0079] 502, chip body;

[0080] 5021, base layer; 5021a, substrate layer; 5022, side frame; 5024, top cover; 5025, signal processing component;

[0081] 5023, sensitive components;

[0082] 1. Quality board; 11. Quality section; 12. Quality section;

[0083] 2. Anchor point;

[0084] 3. Torsion beam;

[0085] 4. Detection electrode; 41. Z-axis detection electrode; 42. Z-axis detection electrode;

[0086] 5. Comb tooth assembly; 51. Fixed teeth; 52. Movable teeth; 53. Comb tooth holes;

[0087] 5023A, first sensitive component;

[0088] 1A, first mass plate; 11A, first mass portion; 111A, first mass sub-portion; 112A, second mass sub-portion; 12A, second mass portion; 121A, third mass sub-portion; 122A, fourth mass sub-portion; 13A, through-hole; 131A, first inner side surface; 132A, second inner side surface; 2A, first anchor point; 3A, first torsion beam; 31A, transverse beam; 32A, longitudinal beam; 4A, first detection electrode; 41A, first Z-axis detection electrode; 42A, second Z-axis detection electrode; 5A, comb tooth assembly; 51A, fixed tooth; 511A, first fixed tooth; 512A, second fixed tooth; 52A, movable tooth; 521A, first movable tooth; 522A, second movable tooth;

[0089] 6A, first elastic member; 7A, first fixing portion; 8A, second fixing portion; 61A, elastic arm; 611A, first elastic arm segment; 612A, second elastic arm segment;

[0090] 9A, second elastic member;

[0091] O1, first axis; D1, first end; D2, second end; D3, third end; D4, fourth end;

[0092] 00A, damping groove; S1, first surface; S2, second surface; 01A, first damping groove; 02A, second damping groove;

[0093] 5023B, second sensitive component;

[0094] 1B, second mass plate; 11B, third mass portion; 12B, fourth mass portion; 13B, through hole; 2B, second anchor point; 3B, second torsion beam; 4B, second detection electrode; 6B, third elastic member; 9B, fourth elastic member. DETAILED DESCRIPTION

[0095] In the embodiments of this application, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first," "second," "third," or "fourth" may explicitly or implicitly include one or more of the features.

[0096] In the embodiments of the present application, the terms "comprises," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not preclude the presence of other identical elements in the process, method, article, or apparatus comprising the element.

[0097] The present application relates to an accelerometer and an electronic device. To facilitate the description of the following embodiments, some professional terms that will be mentioned in the embodiments of the present application are first introduced before introducing the embodiments of the present application. Specifically:

[0098] Micro-electro-mechanical systems (MEMS): Also known as micro-electromechanical systems, microsystems, or micromachines, MEMS refers to devices measuring a few millimeters or smaller. They are miniature devices or systems that integrate microsensors, microactuators, micromechanical structures, micropower supplies, microenergy sources, signal processing and control circuits, high-performance electronic integrated devices, interfaces, and communications.

[0099] The present application provides an electronic device, which can be a 3C product such as a mobile phone, a personal computer (PC), a headset, a wearable device, or an industrial device such as a car or an assembly line. PCs include tablet computers, laptop computers, desktop computers, and the like.

[0100] An electronic device includes an accelerometer for detecting acceleration, or the accelerometer is combined with a MEMS sensor such as a vibration sensor, an acceleration sensor, or a gyroscope to achieve the purpose of noise reduction or reliability improvement.

[0101] This application is exemplified by using an electronic device as a headset. The headset can be a true wireless stereo (TWS) headset, or a headset for an augmented reality (AR) device, a virtual reality (VR) device, or a mixed reality (MR) device. This embodiment and the following embodiments are exemplified by using a TWS headset.

[0102] See also Figure 1 , Figure 1This is a perspective view of an electronic device 100 provided in some embodiments of the present application. The electronic device 100 may include a left earphone 100a and a right earphone 100b. In other embodiments, the electronic device 100 may also include one of the left earphone 100a and the right earphone 100b.

[0103] See also Figure 2 , Figure 2 for Figure 1 The right earphone 100b in the electronic device 100 is shown as a schematic diagram of the exploded structure. The right earphone 100b may include a housing 10, a circuit board 20, a sound generating device 30, a microphone 40 and an accelerometer 50. It is understood that Figure 2 The following figures and the related drawings only schematically illustrate some components of the right earphone 100b, and the actual shapes, sizes, positions and structures of these components are not affected by the present invention. Figure 2 In other embodiments, the right earphone 100b may include, in addition to the aforementioned components, a battery, a system-on-a-chip (SOC) disposed on the circuit board 20, and other electronic components such as radio frequency devices.

[0104] The housing 10 has a receiving space, and electronic components in the right earphone 100b, such as the circuit board 20, the sound generating device 30, the microphone 40 and the accelerometer 50, are all received in the receiving space to protect these electronic components.

[0105] See also Figure 1 and Figure 2 The housing 10 may include an earplug housing 101 and an ear handle housing 102. A first accommodation space 101a is provided in the earplug housing 101, and a second accommodation space (not shown) is provided in the ear handle housing 102. The first accommodation space 101a is connected to the second accommodation space, and the first accommodation space 101a and the second accommodation space together constitute the accommodation space in the housing 10.

[0106] In some embodiments, see Figure 2 The earbud housing 101 may include a front housing 1011 and a rear housing 1012. When the user wears the right earphone 100b, the front housing 1011 faces the user's ear hole, and the rear housing 1012 is located on the side of the front housing 1011 facing away from the ear hole. The earbud housing 101 is formed by assembling the front housing 1011 and the rear housing 1012, which facilitates the assembly of electronic components in the first accommodating space 101a. Based on this, the ear handle housing 102 is connected to the rear housing 1012.

[0107] A portion of the circuit board 20 is located in the first accommodation space 101a, and another portion is located in the second accommodation space. The circuit board 20 can be a rigid circuit board, a flexible circuit board, or a combination of rigid and flexible circuit boards. This application uses a rigid printed circuit board (PCB) as an example.

[0108] The sound-generating device 30 is housed in the first housing space 101a and electrically connected to the circuit board 20. During voice calls, music playback, and other scenarios, the sound-generating device 30 converts electrical signals into sound signals for output to the user. In some embodiments, a sound hole 1013 is formed in the front housing 1011, through which the sound signals generated by the sound-generating device 30 can be output to the user's ears.

[0109] To improve the wearing comfort of the right earphone 100b, please continue to refer to Figure 2 The right earphone 100b may also be provided with a contact sleeve 103. The contact sleeve 103 may be made of a flexible material such as silicone or rubber. The contact sleeve 103 may be used to contact the user's ear to improve the user's wearing comfort. In other embodiments, the right earphone 100b may not be provided with the contact sleeve 103.

[0110] Microphone 40 is housed in the second accommodation space and electrically connected to circuit board 20. In scenarios such as voice calls and recordings, microphone 40 is used to pick up the user's voice signal and convert it into an electrical signal for storage or transmission. Microphone 40 can be a diaphragm microphone, which includes a sound-receiving silicon diaphragm and a silicon back electrode. Both the user's voice signal and the ambient noise signal cause the air to vibrate. The silicon diaphragm vibrates under the force of the vibrating air, causing the capacitance between the silicon diaphragm and the silicon back electrode to change. By detecting the capacitance signal, sound can be picked up. The picked-up sound signal contains noise.

[0111] In some embodiments, see Figure 1 A sound pickup hole 1021 is provided on the ear handle shell 102. The user's voice signal and the noise signal in the environment can enter the second accommodating space through the sound pickup hole 1021 and be picked up by the microphone 40.

[0112] An accelerometer 50 is also housed in the second housing space and electrically connected to the circuit board 20 for detecting vibration signals. Accelerometer 50 may be a voice accelerometer (VACC), also known as a bone conduction accelerometer. A VACC uses a built-in micromechanical structure to detect bone vibration signals caused by a user's speech.

[0113] For examples, see Figure 3, Figure 3 for Figure 2 The schematic diagram of the structure of the right earphone 100b shown is in use. The earplug shell 101 is inserted into the user's ear hole, and the ear handle shell 102 fits the user's face. When the user speaks, the sound will cause slight vibration of the facial bones, and the vibration can be transmitted to the second accommodating space via the ear handle shell 102 to be collected by the accelerometer 50. Based on this, the accelerometer 50 can be fixed to the ear handle shell 102 so that the bone vibration is transmitted to the accelerometer 50 via the ear handle shell 102. The accelerometer 50 can also be fixed to the circuit board 20, and the circuit board 20 is fixed to the ear handle shell 102, so that the bone vibration is transmitted to the circuit board 20 via the ear handle shell 102, and then to the accelerometer 50 via the circuit board 20. This application is exemplified by the accelerometer 50 being fixed to the circuit board 20, and the circuit board 20 being fixed to the ear handle shell 102.

[0114] The ambient noise propagating in the air will not affect the detection accuracy of the VACC. In this way, the detection signal of the accelerometer 50 can be correlated with the sound signal picked up by the microphone 40 to remove the noise signal, thereby achieving the purpose of noise reduction and improving the quality of the sound signal.

[0115] It is understandable that in other embodiments, when the electronic device 100 has other structural forms, the accelerometer 50 may also be a common accelerometer. This embodiment and the following embodiments are exemplified by assuming that the accelerometer 50 is a VACC.

[0116] The structure of the left earphone 100a may be substantially the same as that of the right earphone 100b, and will not be described in detail here.

[0117] The following focuses on the structure of the accelerometer 50 .

[0118] See also Figure 4 and Figure 5 , Figure 4 A perspective view of an accelerometer 50 provided in some embodiments of the present application, Figure 5 for Figure 4 The sectional structure diagram of the accelerometer 50 along the AA direction is shown. The accelerometer 50 is a chip package structure.

[0119] The accelerometer 50 includes a packaging substrate 501, a chip body 502, packaging material 503, and pins 504. The chip body 502 is supported and soldered to the packaging substrate 501. The pins 504 are provided on the surface of the packaging substrate 501 facing away from the chip body 502. The packaging substrate 501 is used to lead the circuits of the chip body 502 to the pins 504. The pins 504 are used to be soldered to external circuits to output signals from the chip body 502 to the external circuits, or to input signals from the external circuits to the chip body 502.

[0120] The packaging material 503 covers the packaging substrate 501 and the chip body 502 to seal and protect the circuit on the packaging substrate 501 and the chip body 502 .

[0121] In some embodiments, please refer to Figure 5 , the chip body 502 can be electrically connected to the packaging substrate 501 in a face-up manner, that is, the bumps (not shown in the figure) of the chip body 502 are located on the surface of the chip body 502 facing away from the packaging substrate 501, and the bumps are electrically connected to the packaging substrate 501 by wire bonding or other methods. In other embodiments, the chip body 502 can also be electrically connected to the packaging substrate 501 in a flip-chip manner, that is, the bumps of the chip body 502 are located on the surface of the chip body 502 facing the packaging substrate 501, and the bumps are directly electrically connected to the packaging substrate 501. This embodiment and the following embodiments are illustrative of the chip body 502 being electrically connected to the packaging substrate 501 in a face-up manner, which should not be considered as a special limitation to the present application.

[0122] See also Figure 6 , Figure 6 Schematic diagram of the cross-sectional structure of a chip body 502 provided in some embodiments of the present application. In this embodiment, the chip body 502 includes a base layer 5021 , a side frame 5022 , a sensitive component 5023 , a top cover 5024 and a signal processing component 5025 .

[0123] The base layer 5021 may include a base layer 5021a and a device layer, a conductive layer, or an insulating layer disposed on the base layer 5021a. The side frame 5022 is disposed on the base layer 5021, and the top cover 5024 is disposed on the side of the side frame 5022 facing away from the base layer 5021. The side frame 5022 and the top cover 5024 may be integrally formed or separately manufactured, and this application does not impose any specific restrictions on this. The base layer 5021, the side frame 5022, and the top cover 5024 form a sealed cavity, and the sensitive component 5023 is accommodated in the sealed cavity. In this way, sound cannot be transmitted to the sensitive component 5023 through the air, thus avoiding external noise interference and achieving sound transmission through vibration.

[0124] The signal processing component 5025 is disposed on the side of the top cover 5024 facing away from the base layer 5021, and the bumps of the chip body 502 are located on the surface of the signal processing component 5025 facing away from the base layer 5021. The signal processing component 5025 is used to process the electrical signals generated by the sensitive component 5023. The signal processing component 5025 can be an application specific integrated circuit (ASIC).

[0125] It is understandable that the chip body 502 can also be of other structural forms. For example, the signal processing component 5025 is arranged between the substrate layer 5021a and the side frame 5022. The substrate layer 5021a and the signal processing component 5025 form a base layer 5021. The base layer 5021 and the side frame 5022 and the top cover 5024 form the above-mentioned sealed cavity.

[0126] The sensitive component 5023 is the main body in the chip body 502 for sensing bone vibration signals. The structure of the sensitive component 5023 is mainly introduced below.

[0127] Please also refer to Figure 6-Figure 8 , Figure 7 for Figure 6 The chip body 502 is shown as a top view after removing the signal processing component 5025 and the top cover 5024. Figure 8 for Figure 7 The schematic structural diagram of the chip body 502 after being rotated 90° along the direction a1 is shown. The sensitive component 5023 may include a mass plate 1 , an anchor point 2 , a torsion beam 3 and a detection electrode 4 .

[0128] The mass plate 1 may be a conductive structure as a whole. For example, the material of the mass plate 1 may be polysilicon or low-resistance single crystal silicon.

[0129] In some embodiments, the mass plate 1 is substantially rectangular. In other embodiments, the mass plate 1 may also be circular, triangular, polygonal, etc. This embodiment and subsequent embodiments are described with the mass plate 1 being rectangular for illustrative purposes only, and this is not to be considered a special limitation of the present application.

[0130] The mass plate 1 is connected to the anchor point 2 via a torsion beam 3. The portions of the mass plate 1 located on either side of the torsion beam 3 are arranged asymmetrically, thus forming a seesaw structure. Based on this, to facilitate the description of the various embodiments below, an XYZ coordinate system is established for the sensitive component 5023. Specifically, the length direction of the torsion beam 3 is defined as the X-axis direction, the direction perpendicular to the length direction of the torsion beam 3 and parallel to the base layer 5021 is defined as the Y-axis direction, and the direction perpendicular to the base layer 5021 is defined as the Z-axis direction. It is understood that the coordinate system setting of the sensitive component 5023 can be flexibly configured according to actual needs and is not specifically limited here. Moreover, the XYZ coordinate systems of the sensitive component 5023 described in the various embodiments below are all established based on the same method and will not be described one by one below.

[0131] Furthermore, to facilitate the description of the various embodiments below, the portions of the mass plate 1 located on either side of the torsion beam 3 are defined as mass portion 11 and mass portion 12. "The portions of the mass plate 1 located on either side of the torsion beam 3 are asymmetrically disposed" means that, given a constant thickness (i.e., the dimension along the Z-axis) of the mass plate 1, the vertical projection area of ​​the mass portion 11 on the base layer 5021 is unequal to the vertical projection area of ​​the mass portion 12 on the base layer 5021. Optionally, the vertical projection area of ​​the mass portion 11 on the base layer 5021 is greater than the vertical projection area of ​​the mass portion 12 on the base layer 5021.

[0132] The detection electrodes 4 are disposed on the base layer 5021 and may include Z-axis detection electrodes. For example, the detection electrodes 4 may include a Z-axis detection electrode 41 and a Z-axis detection electrode 42. The Z-axis detection electrode 41 is located below the mass portion 11, and the Z-axis detection electrode 42 is located below the mass portion 12. When a user speaks, the sound causes slight bone vibration. This bone vibration has a component in the Z-axis direction. When the bone vibration signal component in the Z-axis direction is input into the accelerometer 50, it causes the mass plate 1 to produce a seesaw-like motion, causing the distances between the Z-axis detection electrode 41 and the mass portion 11, and between the Z-axis detection electrode 42 and the mass portion 12 to change. This converts the bone vibration signal component in the Z-axis direction into an electrical signal reflecting the capacitance changes between the Z-axis detection electrode 41 and the mass portion 11, and between the Z-axis detection electrode 42 and the mass portion 12, respectively, to enable detection of the vibration signal.

[0133] When the accelerometer 50 is used in a small-sized electronic device such as a headset, the heat dissipation is difficult due to the small space inside the electronic device, and the high-power devices such as the SOC and radio frequency devices integrated on the circuit board will generate a large amount of heat when they are in operation. When this heat is conducted to the accelerometer 50, the accelerometer 50 will cause temperature drift. In addition, the bone vibration signal generated when a person speaks is weak, and the vibration frequency band is wider, so the accelerometer 50 needs to have a higher sensitivity and a larger signal-to-noise ratio, as well as a larger bandwidth. Moreover, compared with terminal devices such as mobile phones, the probability of headphones falling is greater and the falling height is usually higher, so the accelerometer 50 set in the headset needs to have higher reliability.

[0134] In order to meet the above requirements, the related technology can improve the detection sensitivity of the accelerometer 50 by increasing the area of ​​the mass plate 1 and reduce the Brownian noise by reducing the air pressure in the sealed cavity, thereby improving the signal-to-noise ratio of the accelerometer 50. However, under the premise of a certain thickness, the area of ​​the mass plate 1 is large, and the volume and mass are also correspondingly large, which easily leads to a decrease in the bandwidth of the accelerometer 50. Increasing the in-plane rotation of the mass plate 1 (such as Figure 9As shown in the figure, the risk of the mass plate 1 rotating in the plane and striking and damaging the side frame 5022 will be increased, resulting in reduced reliability. Lowering the air pressure in the sealed cavity will further increase the risk of the mass plate 1 rotating in the plane and striking and damaging the side frame 5022, further reducing reliability.

[0135] To resolve this issue, see Figure 10 , Figure 10 A top view of the chip body 502 provided in some further embodiments of the present application, after removing the signal processing component 5025 and the top cover 5024. In this embodiment, the sensitive component 5023 includes a first sensitive component 5023A and a second sensitive component 5023B arranged along the X-axis. Both the first sensitive component 5023A and the second sensitive component 5023B include a mass plate 1, an anchor point 2, a torsion beam 3, and a detection electrode 4. Furthermore, the first sensitive component 5023A and the second sensitive component 5023B also include multiple comb tooth assemblies 5, each of which includes fixed teeth 51 and movable teeth 52. In addition to the Z-axis detection electrode, the detection electrode 4 also includes a Y-axis detection electrode (not shown). The fixed teeth 51 are fixed to the Y-axis detection electrode, and the mass plate 1 is provided with comb tooth holes 53 that extend through the mass plate 1 along the Z-axis, with portions of the fixed teeth 51 being accommodated within the comb tooth holes 53. The movable teeth 52 are provided on the mass plate 1. The fixed teeth 51 and the movable teeth 52 are spaced apart along the Y-axis. When the accelerometer 50 senses the input of the bone vibration signal component in the Y-axis direction, the mass plate 1 will drive the movable tooth 52 to move along the Y-axis direction relative to the fixed tooth 51, thereby causing the capacitance between the Y-axis detection electrode and the mass plate 1 to change. The Y-axis detection electrode detects the change in distance from the mass plate 1, thereby converting the bone vibration signal component in the Y-axis direction into an electrical signal reflecting the change in capacitance between the mass plate 1 and the Y-axis detection electrode.

[0136] In this way, the mass plate 1 in each sensitive component is used not only to detect the bone vibration signal component in the Z-axis direction, but also to detect the bone vibration signal component in the Y-axis direction. In other words, the mass plate 1 is used as both the Z-axis mass plate and the Y-axis mass plate, thereby forming a dual-axis shared mass plate structure, which can increase the signal-to-noise ratio and enhance the sensitivity of detection. Moreover, since the Z-axis and the Y-axis share the same mass plate 1, the Z-axis mass plate and the Y-axis mass plate are not independently provided. Under the premise that the size of the chip body 502 is constant, the area and mass of the Z-axis mass plate (equal to the area and mass of the mass plate 1) can be designed to be larger, and the area and mass of the Y-axis mass plate (equal to the area and mass of the mass plate 1) can also be designed to be larger, thereby enhancing the detection sensitivity of the bone vibration signal components in the Z-axis direction and the Y-axis direction. Furthermore, while maintaining the size of the accelerometer 50, providing two sensitive components can reduce the area of ​​the mass plate 1 within a single sensitive component. This reduces the impact force exerted on the side frame by the mass plate 1 during in-plane torsion, lowering the risk of the mass plate 1 damaging the side frame 5022 or the retaining structure during in-plane torsion, thereby improving reliability. Because the mass plate 1 within a single sensitive component has a smaller area and relatively lower mass, it has a higher natural frequency and can pick up high-frequency vibration signals, thus ensuring bandwidth.

[0137] In some embodiments, please refer to Figure 10 In the two sensitive components, the mass portions 11 and 12 of the mass plate 1 are placed in opposite directions. That is, in one sensitive component, the direction from the mass portion 11 of the mass plate 1 to the mass portion 12 is a first direction, while in the other sensitive component, the direction from the mass portion 11 to the mass portion 12 is a second direction, with the first direction and the second direction being opposite. This arrangement of the two mass plates 1 in opposite directions can suppress temperature drift along the Y-axis.

[0138] However, since the detection principle in the Z-axis direction is realized by utilizing the asymmetry of the mass plates on both sides of the torsion beam 3, please refer to Figure 11 , Figure 11 for Figure 10The schematic diagram of the cross-sectional structure of the chip body 502 along the BB direction shows that when there is a temperature gradient in the Z-axis direction of the accelerometer 50, such as during the high-load operation of the SOC on the circuit board 20 or the high-power transmission of the RF device, the heat on the circuit board 20 is transferred from the base layer 5021 of the accelerometer 50 to the top cover 5024, so that the temperature of the gas between the mass plate 1 and the base layer 5021 is greater than the temperature of the gas between the mass plate 1 and the top cover 5024. The gas between the mass plate 1 and the base layer 5021 expands, which can push the mass parts of different areas on both sides of the torsion beam 3 (that is, the mass part 11 and the mass part 12), and generate torques M1 and M2 of different sizes on the two mass parts, causing the mass plate 1 to drive the torsion beam 3 to rotate around the axis formed by the torsion beam 3 and the anchor point 2, thereby generating a temperature drift in the Z-axis direction. Moreover, the design of the dual sensitive components further amplifies the influence of this temperature gradient and makes the temperature drift more significant. In addition, in order to ensure the detection sensitivity in the Y-axis direction, Figure 10 The dual-sensitive assembly shown generally cannot use a torsion beam 3 with greater stiffness, so the dual-sensitive unit has limited effect on suppressing the in-plane rotation of the mass plate 1 and still has major reliability issues.

[0139] First, to solve the problem of temperature drift in the Z-axis direction, refer to Figure 12 and Figure 13 , Figure 12 Schematic diagram of the cross-sectional structure of the chip body 502 provided in some embodiments of the present application, Figure 13 for Figure 12 The chip body 502 is shown as a top view after the signal processing component 5025 and the top cover 5024 are removed.

[0140] The chip body 502 includes a first sensitive component 5023A, which is disposed in the sealed cavity.

[0141] The first sensitive component 5023A may include a first mass plate 1A, a first anchor point 2A, a first torsion beam 3A, and a first detection electrode 4A.

[0142] The first anchor point 2A can be fixed to the base layer 5021. In other embodiments, the first anchor point 2A can also be fixed to the top cover 5024. This embodiment and the following embodiments are illustrative of the first anchor point 2A being fixed to the base layer 5021, which cannot be considered as a special limitation to the present application.

[0143] The first mass plate 1A may be a conductive structure as a whole. For example, the material of the first mass plate 1A may be polysilicon or low-resistance single crystal silicon.

[0144] In some embodiments, the first mass plate 1A is substantially rectangular. Therefore, the width of the first mass plate 1A can be aligned with the X-axis. In other embodiments, the first mass plate 1A can also be circular, triangular, polygonal, or other shapes. This embodiment and the following embodiments illustrate the first mass plate 1A as a rectangular plate, which is not intended to be a limitation of the present application.

[0145] The first mass plate 1A is connected to the first anchor point 2A via a first torsion beam 3A. The first torsion beam 3A at least allows the first mass plate 1A to drive the first torsion beam 3A to rotate relative to the rotation axis formed by the first torsion beam 3A and the first anchor point 2A, so that the first mass plate 1A can generate a seesaw-like motion.

[0146] In some embodiments, see Figure 13 The first torsion beam 3A may include a transverse beam 31A and two longitudinal beams 32A. The transverse beam 31A extends along the X-axis, with the longitudinal midpoint of the transverse beam 31A fixed to the first anchor point 2A. The two longitudinal beams 32A extend perpendicularly to the transverse beam 31A, and the longitudinal midpoints of the two longitudinal beams 32A are connected to the ends of the transverse beam 31A, respectively. Both ends of the two longitudinal beams 32A are fixed to the first mass plate 1A. This first torsion beam 3A has a simple structure and is easy to manufacture. While allowing the first mass plate 1A to drive the first torsion beam 3A to rotate relative to the rotation axis formed by the first torsion beam 3A and the first anchor point 2A, it also allows the first mass plate 1A to move relative to the first anchor point 2A along the Y-axis, thereby facilitating the detection of the bone vibration signal component in the Y-axis direction.

[0147] Of course, the first torsion beam 3A can also have other structural forms, as long as it allows the first mass plate 1A to drive the first torsion beam 3A to rotate relative to the rotation axis formed by the first torsion beam 3A and the first anchor point 2A. This application does not make any specific restrictions on this. The number of first anchor points 2A can be one or two. When the number of first anchor points 2A is one, please refer to Figure 13 The first anchor point 2A is connected to the midpoint of the first torsion beam 3A in the longitudinal direction, and the first mass plate 1A is connected to both ends of the first torsion beam 3A. When there are two first anchor points 2A, the two first anchor points 2A can be respectively connected to the two ends of the first torsion beam 3A in the longitudinal direction, and the first mass plate 1A is connected to the middle part of the first torsion beam 3A. This application does not make any specific limitation on this.

[0148] To facilitate the description of the embodiments below, the parts of the first mass plate 1A located on both sides of the first torsion beam 3A are defined as a first mass part 11A and a second mass part 12A.

[0149] Based on this, at least one of the first mass portion 11A and the second mass portion 12A is provided with a through hole 13A. In other words, the first mass portion 11A may be provided with a through hole 13A, while the second mass portion 12A may not be provided with a through hole 13A. Alternatively, the first mass portion 11A may not be provided with a through hole 13A, while the second mass portion 12A may be provided with a through hole 13A. Alternatively, both the first mass portion 11A and the second mass portion 12A may be provided with a through hole 13A. This embodiment and the following embodiments are described by way of example based on the assumption that both the first mass portion 11A and the second mass portion 12A are provided with a through hole 13A. This is not to be considered a special limitation of the present application.

[0150] The sum of the areas of the through holes 13A on the first mass portion 11A is not equal to the sum of the areas of the through holes 13A on the second mass portion 12A. When the first mass portion 11A or the second mass portion 12A is not provided with the through holes 13A, the sum of the areas of the through holes 13A on the first mass portion 11A or the second mass portion 12A is 0.

[0151] In some embodiments, see Figure 13 The sum of the areas where the through holes 13A are provided on the first mass portion 11A is smaller than the sum of the areas where the through holes 13A are provided on the second mass portion 12A.

[0152] Also, please continue reading Figure 13 The outer contours of the first mass portion 11A and the second mass portion 12A are symmetrically arranged about the first torsion beam 3A. The outer contours of the first mass portion 11A and the second mass portion 12A refer to the outer edge contours of the first mass portion 11A and the outer edge contours of the second mass portion 12A, respectively, after ignoring the thickness of the first mass portion 11A and assuming the first mass portion 11A is equivalent to a planar structure.

[0153] In this way, the sum of the setting areas of the through holes 13A on the first mass part 11A is designed to be unequal to the sum of the setting areas of the through holes 13A on the second mass part 12A, so that the masses of the first mass part 11A and the second mass part 12A can be made asymmetric, so as to form a seesaw structure, which can realize the detection of the bone vibration signal component in the Z-axis direction. At the same time, because the outer contours of the first mass portion 11A and the second mass portion 12A are symmetrically arranged about the first torsion beam 3A, the outer contour of the first mass portion 11A is defined as the first outer contour, and the outer contour of the second mass portion 12A is defined as the second outer contour. The area enclosed by the first outer contour is equal to the area enclosed by the second outer contour, and the geometric centers of the areas enclosed by the first outer contour and the second outer contour are symmetrically arranged about the first torsion beam 3A. Therefore, when a temperature gradient exists in the Z-axis direction of the accelerometer 50, the gas between the first mass plate 1A and the base layer 5021 expands, pushing the mass portions of approximately equal area on both sides of the first torsion beam 3A (i.e., the first mass portion 11A and the second mass portion 12A), generating approximately equal torques on the two mass portions, achieving a substantial balance and making it less likely that the first mass plate 1A will experience seesaw motion. This can reduce or eliminate temperature drift of the accelerometer 50 in the Z-axis direction.

[0154] The first detection electrode 4A may include a first Z-axis detection electrode 41A and a second Z-axis detection electrode 42A. In some embodiments, the first Z-axis detection electrode 41A and the second Z-axis detection electrode 42A may be disposed on the base layer 5021. In other embodiments, the first Z-axis detection electrode 41A and the second Z-axis detection electrode 42A may also be disposed on the top cover 5024. This embodiment and the following embodiments are described illustratively using the first Z-axis detection electrode 41A and the second Z-axis detection electrode 42A disposed on the base layer 5021. Along the Z-axis direction, the first Z-axis detection electrode 41A opposes at least a portion of the first mass portion 11A. In other words, the vertical projection of at least a portion of the first mass portion 11A on the base layer 5021 overlaps with the first Z-axis detection electrode 41A. Along the Z-axis direction, the second Z-axis detection electrode 42A opposes at least a portion of the second mass portion 12A. In other words, the vertical projection of at least a portion of the second mass portion 12A on the base layer 5021 overlaps with the second Z-axis detection electrode 42A. When the bone vibration signal component in the Z-axis direction is input into the accelerometer 50, the first mass plate 1A will produce a seesaw-like motion, causing the distance between the first Z-axis detection electrode 41A and the first mass part 11A, and between the second Z-axis detection electrode 42A and the second mass part 12A to change, thereby converting the bone vibration signal component in the Z-axis direction into an electrical signal reflecting the capacitance change between the first Z-axis detection electrode 41A and the first mass part 11A, and between the second Z-axis detection electrode 42A and the second mass part 12A, thereby realizing the detection of the vibration signal.

[0155] Through hole 13A can be a comb-tooth hole for accommodating a comb-tooth structure in the X-axis or Y-axis direction, or a damping hole for balancing the air pressure above and below the first mass plate 1A to reduce noise, or a hole for other purposes. This embodiment and the following embodiments illustrate through hole 13A as a comb-tooth hole, which is not to be construed as a special limitation of the present application. Through hole 13A can be large or small, and the present application does not specifically limit the size of through hole 13A.

[0156] In some embodiments, please refer to Figure 13The number of through holes 13A is multiple, and the multiple through holes 13A can be formed into two groups of through holes 13A, namely a first group of through holes and a second group of through holes. The first group of through holes is provided in the first mass portion 11A, and the second group of through holes is provided in the second mass portion 12A. The vertical projection area of ​​each through hole 13A in the first group of through holes on the base layer 5021 is equal to the vertical projection area of ​​each through hole 13A in the second group of through holes on the base layer 5021. The number of through holes 13A provided in the first mass portion 11A is less than the number of through holes 13A provided in the second mass portion 12A. As a result, the total area of ​​the through holes 13A provided in the first mass portion 11A is less than the total area of ​​the through holes 13A provided in the second mass portion 12A. This results in a simple structural design and is easy to implement.

[0157] In some embodiments, please refer to Figure 13 The first group of through holes can include two rows of through holes 13A arranged along the X-axis, symmetrically arranged about the first axis O1. The first axis O1 is parallel to the first mass plate 1A, passes through the midpoint of the length of the first torsion beam 3A, and is perpendicular to the length of the first torsion beam 3A. Each row of through holes 13A includes a plurality of through holes 13A arranged parallel to the first axis O1. For example, each row of through holes 13A includes two through holes 13A. In this manner, the array arrangement of the first group of through holes on the first mass portion 11A ensures that the first mass plate 1A remains balanced along the X-axis.

[0158] Likewise, please continue to see Figure 13 The second group of through holes also includes two rows of through holes 13A arranged along the X-axis. These two rows of through holes 13A are symmetrically arranged about the first axis O1. Each row of through holes 13A includes multiple through holes 13A arranged parallel to the first axis O1. For example, each row of through holes 13A includes four through holes 13A. In this way, the second group of through holes is arranged in an array on the second mass portion 12A, ensuring that the first mass plate 1A remains balanced along the X-axis.

[0159] Based on the above, please continue to refer to Figure 13 The first sensitive component 5023A further includes a comb tooth component 5A. The comb tooth component 5A includes fixed teeth 51A and movable teeth 52A.

[0160] The first detection electrode 4A includes not only the first Z-axis detection electrode 41A and the second Z-axis detection electrode 42A, but also a Y-axis detection electrode (not shown in the figure). The Y-axis detection electrode is provided on the base layer 5021. Figure 13The fixed teeth 51A are fixed to the base layer 5021 and electrically connected to the Y-axis detection electrodes. In some embodiments, the fixed teeth 51A can be directly disposed on the Y-axis detection electrodes to provide electrical connection thereto. The ends of the fixed teeth 51A facing away from the base layer 5021 are respectively accommodated within the aforementioned through-holes 13A. The movable teeth 52A are disposed on the first mass plate 1A. In some embodiments, the portion of the first mass plate 1A where the through-holes 13A are located forms the movable teeth 52A. The movable teeth 52A are spaced apart from the fixed teeth 51A along the Y-axis.

[0161] In some embodiments, the number of comb tooth assemblies 5A can be equal to the number of through holes 13A, and they correspond one to one. The end of the fixed teeth 51A in each comb tooth assembly 5A, facing away from the base layer 5021, is accommodated in the through hole 13A corresponding to the comb tooth assembly 5A. Of course, in other embodiments, the number of comb tooth assemblies 5A can also be different from the number of through holes 13A. In this way, multiple comb tooth assemblies 5A can correspond to one through hole 13A. This embodiment and the following embodiments are described for illustrative purposes based on the fact that the number of comb tooth assemblies 5A can be equal to the number of through holes 13A and they correspond one to one. This should not be considered a special limitation of the present application.

[0162] When the accelerometer 50 senses the input of the bone vibration signal component in the Y-axis direction, the first mass plate 1A will drive the movable tooth 52A to move relative to the fixed tooth 51A along the Y-axis direction, thereby causing the capacitance between the Y-axis detection electrode and the first mass plate 1A to change. The Y-axis detection electrode detects the change in distance from the first mass plate 1A, thereby converting the bone vibration signal component in the Y-axis direction into an electrical signal reflecting the change in capacitance between the first mass plate 1A and the Y-axis detection electrode.

[0163] In this way, the first mass plate 1A detects bone vibration signal components in the Y-axis direction in addition to the Z-axis. In other words, the first mass plate 1A functions as both a Z-axis mass plate and a Y-axis mass plate, creating a dual-axis shared mass plate structure that increases detection sensitivity.

[0164] In some embodiments, please refer to Figure 13The Y-axis detection electrodes include a first Y-axis detection electrode and a second Y-axis detection electrode. Each through-hole 13A includes a first inner side surface 131A and a second inner side surface 132A aligned along the Y-axis direction. The movable teeth 52A include a first movable tooth 521A and a second movable tooth 522A. Optionally, the first movable tooth 521A can be formed by the portion of the first mass plate 1A where the first inner side surface 131A is located, and the second movable tooth 522A can be formed by the portion of the first mass plate 1A where the second inner side surface 132A is located. The fixed teeth 51A housed in each through-hole 13A include a first fixed tooth 511A and a second fixed tooth 512A. The first fixed tooth 511A is located between the first inner side surface 131A and the second fixed tooth 512A, and the second fixed tooth 512A is located between the first fixed tooth 511A and the second inner side surface 132A. The first fixed tooth 511A is fixed to the first Y-axis detection electrode, and the second fixed tooth 512A is fixed to the second Y-axis detection electrode.

[0165] In this way, when the first mass plate 1A drives the movable tooth 52A to move relative to the fixed tooth 51A along the Y-axis direction, so that the distance between the first fixed tooth 511A and the first movable tooth 521A decreases, the distance between the second fixed tooth 512A and the second movable tooth 522A increases; when the first mass plate 1A drives the movable tooth 52A to move relative to the fixed tooth 51A along the Y-axis direction, so that the distance between the first fixed tooth 511A and the first movable tooth 521A increases, the distance between the second fixed tooth 512A and the second movable tooth 522A decreases, thereby forming a differential comb tooth structure, which can improve the detection accuracy of the vibration signal in the Y-axis direction.

[0166] The first group of through holes can be provided throughout the entire area of ​​the first mass portion 11A or in a local area of ​​the first mass portion 11A. Similarly, the second group of through holes can be provided throughout the entire area of ​​the second mass portion 12A or in a local area of ​​the second mass portion 12A. This embodiment and the following embodiments illustrate the first group of through holes and the second group of through holes being provided in a local area of ​​the first mass portion 11A and a local area of ​​the second mass portion 12A, respectively, and this is not to be considered a special limitation of the present application.

[0167] In some embodiments, please refer to Figure 13The first mass portion 11A includes a first mass sub-portion 111A and a second mass sub-portion 112A. Along the Z-axis, the first Z-axis detection electrode 41A opposes the first mass sub-portion 111A, and a first group of through-holes is provided in the second mass sub-portion 112A. The second mass portion 12A includes a third mass sub-portion 121A and a fourth mass sub-portion 122A. Along the Z-axis, the second Z-axis detection electrode 42A opposes the third mass sub-portion 121A, and a second group of through-holes is provided in the fourth mass sub-portion 122A. In this way, the through-holes on the first mass portion 11A and the first Z-axis detection electrode 41A, as well as the through-holes on the second mass portion 12A and the second Z-axis detection electrode 42A, are staggered. The through-holes on the first mass portion 11A and the through-holes on the second mass portion 12A can be used as comb holes to accommodate comb teeth for detecting signals in other directions. For example, in the embodiment of the present application, the comb holes are used to accommodate comb teeth for detecting bone vibration signal components in the Y-axis direction.

[0168] In some embodiments, please refer to Figure 13 The first mass subsection 111A can be located on the side of the second mass subsection 112A facing away from the first torsion beam 3A, and the third mass subsection 121A can be located on the side of the fourth mass subsection 122A facing away from the first torsion beam 3A. This arrangement allows the first and third mass subsections 111A and 121A to be positioned away from the first torsion beam 3A. When the first mass plate 1A experiences a seesaw-like motion and rotates at a constant angle, the distances between the first mass subsection 111A and the first Z-axis detection electrode 41A, and between the third mass subsection 121A and the second Z-axis detection electrode 42A, vary significantly, leading to significant capacitance changes. This improves detection sensitivity and accuracy.

[0169] Of course, in other embodiments, the first mass sub-portion 111A may also be located between the second mass sub-portion 112A and the first torsion beam 3A, and the third mass sub-portion 121A may also be located between the fourth mass sub-portion 122A and the first torsion beam 3A. This application does not make specific limitations on this.

[0170] In some embodiments, please refer to Figure 13 The first group of through holes can be evenly distributed throughout the second mass sub-segment 112A, and the second group of through holes can be evenly distributed throughout the fourth mass sub-segment 122A. This allows gas above and below the second mass sub-segment 112A and the fourth mass sub-segment 122A to convect through the first and second groups of through holes, respectively, with minimal flow resistance and faster heat exchange, thus reducing the temperature gradient and temperature drift along the Z-axis.

[0171] In some embodiments, the first mass subsection 111A and the third mass subsection 121A may also be provided with damping holes (not shown) to allow gas above and below the first mass subsection 111A and the third mass subsection 121A to convect through the damping holes, thereby accelerating heat exchange and further reducing temperature drift in the Z-axis direction. Of course, in other embodiments, the first mass subsection 111A and the third mass subsection 121A may not be provided with damping holes, and this application does not specifically limit this.

[0172] The comb tooth assembly 5A in the above embodiment is a Y-axis comb tooth assembly for detecting the bone vibration signal component in the Y-axis direction. In other embodiments, in addition to the Y-axis comb tooth assembly, the first sensitive assembly 5023A may also be provided with an X-axis comb tooth assembly. A part of the above-mentioned through hole 13A is the comb tooth hole of the Y-axis comb tooth assembly, and the other part is the comb tooth hole of the X-axis comb tooth assembly, or only the X-axis comb tooth assembly is provided, and the Y-axis comb tooth assembly is not provided. The above-mentioned through hole 13A is the comb tooth hole of the X-axis comb tooth assembly, and this application does not make any specific limitation on this.

[0173] Second, to address the reliability issues of sensitive components, see Figure 14 , Figure 14 A top view of the chip body 502, shown in some further embodiments of the present application, after removing the signal processing component 5025 and the top cover 5024. In this embodiment, the first sensitive component 5023A includes, in addition to the aforementioned first mass plate 1A, first anchor point 2A, first torsion beam 3A, and first detection electrode 4A, a first elastic member 6A. The first elastic member 6A is located on the side of the first mass portion 11A facing away from the second mass portion 12A. One end of the first elastic member 6A is connected to the first mass portion 11A, and the other end is fixed relative to the base layer 5021.

[0174] In this way, when the first mass plate 1A experiences in-plane torsion due to external impact, the first elastic member 6A deforms. This deformation accumulates elastic force, which prevents further in-plane torsion of the first mass portion 11A, thereby improving the in-plane torsional stiffness of the first mass portion 11A. Furthermore, because the first elastic member 6A is located on the side of the first mass portion 11A facing away from the second mass portion 12A, the first elastic member 6A and the first mass plate 1A are arranged side by side in the XY plane, avoiding overlapping thicknesses and facilitating a thinner chip body.

[0175] In some embodiments, see Figure 14, the first sensitive component 5023A may also include a first fixing portion 7A and a second fixing portion 8A. The first fixing portion 7A is arranged at the end of the first mass portion 11A facing away from the second mass portion 12A, and the second fixing portion 8A is located on the side of the first fixing portion 7A facing away from the first mass portion 11A, and the second fixing portion 8A is fixed relative to the base layer 5021. Optionally, the second fixing portion 8A can be directly fixed to the base layer 5021, or fixed to the side frame 5022 or the top cover 5024. This application is exemplified by the second fixing portion 8A being directly fixed to the base layer 5021. The first elastic member 6A is connected between the first fixing portion 7A and the second fixing portion 8A. In this way, with the help of the first fixing portion 7A, a certain distance can be maintained between the first elastic member 6A and the first mass portion 11A in the Y-axis direction, which can avoid position interference between the first elastic member 6A and the first mass portion 11A during relative movement. At the same time, with the help of the second fixing portion 8A, a certain distance can be maintained between the first elastic member 6A and the base layer 5021 in the Z-axis direction, so that the first elastic member 6A has deformation space in the Z-axis direction.

[0176] In other embodiments, the first sensitive component 5023A may not be provided with at least one of the first fixing portion 7A and the second fixing portion 8A.

[0177] In some embodiments, the first elastic member 6A has various structural forms, such as springs, rubber, silicone, etc. This application uses the first elastic member 6A as a flat spring for exemplary description.

[0178] See also Figure 15 , Figure 15 for Figure 14 The schematic diagram of the structure of the first elastic member 6A in the chip body 502 is shown. The first elastic member 6A includes at least one elastic arm 61A. Figure 15 In the illustrated embodiment, there is one elastic arm 61A, and each elastic arm 61A may include a plurality of first elastic arm segments 611A and at least one second elastic arm segment 612A.

[0179] Each first elastic arm segment 611A extends along the length direction of the first torsion beam 3A (that is, the X-axis direction). In other words, the extension direction of the first elastic arm segment 611A is parallel to the length direction of the first torsion beam 3A. The "parallelism" is not limited to absolute parallelism, but refers to approximate parallelism within a certain error range.

[0180] The plurality of first elastic arm sections 611A are arranged along the Y-axis direction, and a gap exists between two adjacent first elastic arm sections 611A.

[0181] The above-mentioned multiple first elastic arm segments 611A are alternately connected with at least one second elastic arm segment 612A in sequence. That is, the arrangement of the multiple first elastic arm segments 611A and at least one second elastic arm segment 612A is: an alternating arrangement of the first elastic arm segment 611A, the second elastic arm segment 612A, the first elastic arm segment 611A, ..., and along the alternating arrangement direction, one end of the first elastic arm segment 611A is connected to one end of the next second elastic arm segment 612A, and the other end of the next second elastic arm segment 612A is connected to one end of the next first elastic arm segment 611A of the second elastic arm segment 612A, thereby being connected in sequence.

[0182] In this way, the elastic arm 61A is a roughly planar spring structure, occupying a relatively low height in the Z-axis direction, which facilitates a thinner chip body 502. Furthermore, the first elastic arm segment 611A and the second elastic arm segment 612A can bend along the Z-axis, allowing the first mass plate 1A to generate a seesaw-like motion about the rotation axis formed by the first torsion beam 3A and the first anchor point 2A. This can reduce the effect of the first elastic member 6A on the seesaw-like motion stiffness of the first mass plate 1A. Furthermore, due to the gap between two adjacent first elastic arm segments 611A, the first elastic arm segments 611A can bend along the Y-axis, compressing or stretching the first elastic member 6A along the Y-axis, thereby allowing the first mass plate 1A to move along the Y-axis and reducing the effect of the first elastic member 6A on the motion stiffness of the first mass plate 1A along the Y-axis.

[0183] In some embodiments, see Figure 15 Among the multiple first elastic arm segments 611A, the first elastic arm segment 611A closest to the first mass portion 11A is connected to the first fixing portion 7A. Among the multiple first elastic arm segments 611A, the first elastic arm segment 611A farthest from the first mass portion 11A is connected to the end of the second fixing portion 8A facing away from the base layer 5021. This structure is simple and easy to implement.

[0184] In some embodiments, see Figure 15 Of the two adjacent first elastic arm segments 611A, one first elastic arm segment 611A has a first end D1 and a second end D2, respectively, while the other first elastic arm segment 611A has a third end D3 and a fourth end D4, respectively. The direction from the first end D1 to the second end D2 is the same as the direction from the third end D3 to the fourth end D4. Therefore, the second elastic arm segment 612A between the two adjacent first elastic arm segments 611A is connected between the second end D2 and the fourth end D4.

[0185] In this way, there are no obstacles in the gap between two adjacent first elastic arm segments 611A. Given a certain number of first elastic arm segments 611A and second elastic arm segments 612A, as well as the spacing between two adjacent first elastic arm segments 611A, the elastic arm 61A can be subjected to a relatively large amount of compression deformation along the Y-axis, thereby accommodating the detection of relatively large bone vibration signals along the Y-axis. Given a certain designed compression deformation of the elastic arm 61A along the Y-axis and the spacing between two adjacent first elastic arm segments 611A, the number of first elastic arm segments 611A and second elastic arm segments 612A can be reduced to reduce the length of the elastic arm 61A along the Y-axis, thereby reducing the volume of the first elastic member 6A and, therefore, the chip body 502.

[0186] In some other embodiments, see Figure 16 , Figure 16 Schematic diagrams of the structure of the first elastic member 6A in the chip body are provided for further embodiments of the present application. In this embodiment, a second elastic arm segment 612A between two adjacent first elastic arm segments 611A is connected between the second end D2 of one first elastic arm segment 611A and the third end D3 of the other first elastic arm segment 611A. This longer second elastic arm segment 612A can generate a greater Z-axis bending deformation, thereby reducing the effect of the elastic arm 61A on the seesaw motion stiffness of the first mass plate 1A.

[0187] The number of the elastic arm 61A in the first elastic member 6A may be one or more. Figure 15 and Figure 16 The elastic arm 61A is illustrated as one. In other embodiments, please refer to Figure 17 or Figure 18 , Figure 17 This is a schematic structural diagram of the first elastic member 6A in the chip body provided in some other embodiments of the present application. Figure 18 Schematic diagrams of the structure of the first elastic member 6A in the chip body 502 are provided in further embodiments of the present application. In these two embodiments, the first elastic member 6A includes two elastic arms 61A, located on either side of the first axis O1 and symmetrically arranged about the first axis O1. The two elastic arms 61A generate a strong elastic force, effectively preventing further in-plane twisting of the first mass portion 11A.

[0188] In the first elastic member 6A described in any of the above embodiments, optionally, the width of the first elastic arm section 611A may be less than or equal to the width of the first torsion beam 3A. The width of the first elastic arm section 611A refers to the dimension of the first elastic arm section 611A along the Y-axis direction. The width of the first torsion beam 3A refers to the width of the portion of the first torsion beam 3A extending along the length direction of the first torsion beam 3A (that is, the X-axis direction). For example, when the first torsion beam 3A includes a transverse beam 31A and two longitudinal beams 32A, the width of the first torsion beam 3A refers to the width of the transverse beam 31A. The width of the transverse beam 31A specifically refers to the dimension of the transverse beam 31A along the Y-axis direction.

[0189] In this way, the first elastic arm section 611A has a smaller rigidity and is easier to bend, which can further reduce the influence of the elastic arm 61A on the seesaw motion rigidity and the motion rigidity in the Y-axis direction of the first mass plate 1A.

[0190] In the first elastic member 6A described in any of the above embodiments, optionally, the gap width between two adjacent first elastic arm segments 611A is 2-5 times the width of the first elastic arm segment 611A. The gap width between two adjacent first elastic arm segments 611A refers to the distance between the two adjacent first elastic arm segments 611A along the Y-axis.

[0191] This allows for a larger gap width between adjacent first elastic arm segments 611A. Given a certain number of first elastic arm segments 611A and second elastic arm segments 612A, this allows for a greater degree of compressive deformation of the elastic arm 61A along the Y-axis, enabling detection of relatively large bone vibration signals along the Y-axis. Given a certain designed degree of compressive deformation of the elastic arm 61A along the Y-axis, the number of first elastic arm segments 611A and second elastic arm segments 612A can be reduced to reduce the length of the elastic arm 61A along the Y-axis, thereby reducing the size of the first elastic member 6A.

[0192] In the first elastic member 6A described in any of the above embodiments, optionally, the size of the first elastic member 6A in the X-axis direction is less than or equal to the size of the first mass plate 1A in the X-axis direction. Optionally, the size of the first elastic member 6A in the X-axis direction may be equal to the length of the first torsion beam 3A. The "equal" here is not limited to equality in an absolute sense, but refers to approximate equality within a certain error range.

[0193] In this way, the first elastic member 6A can provide cushioning and vibration reduction for the first mass plate 1A over a wide range in the longitudinal direction of the first torsion beam 3A, minimizing the risk of damage to the side frame 5022 or the retaining structure caused by the first mass plate 1A during in-plane torsion. This does not affect the width of the first sensitive component 5023A in the first direction.

[0194] In order to verify the effect of the first elastic member 6A on the in-plane torsional stiffness of the first mass plate 1A, the resonant frequency of the first mass plate 1A in the in-plane torsional mode can be simulated for the chip body 502 without the first elastic member 6A and with the first elastic member 6A. The higher the resonant frequency of the first mass plate 1A in the in-plane torsional mode, the greater the in-plane torsional stiffness of the first mass plate 1A. The simulation parameters are as follows: the first elastic member 6A adopts Figure 15 In the illustrated structure, the width of the first torsion beam 3A is 4 μm, the width of the first elastic arm segment 611A within the first elastic member 6A is 2 μm, the spacing between adjacent first elastic arm segments 611A is 6 μm, and the dimension of the first elastic member 6A in the Y-axis direction is equal to the length of the first torsion beam 3A. Simulation results show that in the chip body 502 without the first elastic member 6A, the resonant frequency of the first mass plate 1A in the in-plane torsional mode is 1900 Hz. In the chip body 502 with the first elastic member 6A, the resonant frequency of the first mass plate 1A in the in-plane torsional mode is 5500 Hz. This higher resonant frequency indicates a higher in-plane torsional stiffness of the first mass plate 1A. This demonstrates that the provision of the first elastic member 6A can improve the in-plane torsional stiffness of the first mass plate 1A within the chip body 502.

[0195] Also, see Figure 19 , Figure 19 Schematic diagram of the displacement field of the first mass plate 1A along the Y-axis at a first moment in a chip body 502 without and with the first elastic member 6A. At this first moment, the vibration magnitude and direction transmitted to the chip body 502 without and with the first elastic member 6A are the same. Specifically, Figure 19 (a) is a schematic diagram of the displacement field of the first mass plate 1A along the Y-axis direction at the first moment in the chip body 502 without the first elastic member 6A. Figure 19 (b) is a schematic diagram of the displacement field of the first mass plate 1A along the Y-axis at the first moment in the chip body 502 provided with the first elastic member 6A. The unit of displacement along the Y-axis is μm. Figure 16 It can be seen that whether the first elastic member 6A is provided has little effect on the displacement field of the first mass plate 1A along the Y-axis direction and can be basically ignored. Therefore, the first elastic member 6A has little effect on the sensitivity of the chip body 502 along the Y-axis direction.

[0196] In some embodiments, the first elastic member 6A may further include three, four or five elastic arms, which is not specifically limited in this application.

[0197] The above embodiments describe the structure of the first elastic member 6A. In other embodiments, please refer to Figure 20 , Figure 20A top view of the chip body 502, provided in some further embodiments of the present application, after removing the signal processing component 5025 and the top cover 5024. In this embodiment, the chip body 502 may include, in addition to the first elastic member 6A, a second elastic member 9A. The second elastic member 9A is connected between the end of the second mass portion 12A facing away from the first mass portion 11A and the base layer 5021.

[0198] In this way, when the first mass plate 1A produces in-plane torsion under the action of external impact force, the first elastic member 6A and the second elastic member 9A can be deformed at the same time. After the first elastic member 6A and the second elastic member 9A are deformed, elastic force is accumulated. The elastic force is large and can effectively resist the impact force, thereby playing a better shock-absorbing role.

[0199] The structure of the second elastic member 9A can be the same as the structure of the first elastic member 6A described in any of the above embodiments, and will not be described in detail here. In some embodiments, the chip body 502 can also be provided with the second elastic member 9A instead of the first elastic member 6A, and this application does not make specific limitations on this.

[0200] It should be noted that the above embodiment is based on the first elastic member 6A or the second elastic member 9A being connected to the Figure 14 The first elastic member 6A or the second elastic member 9A is connected between the first mass plate 1A and the base layer 5021 in the chip body 502 to improve the in-plane torsional stiffness of the first mass plate 1A. In other embodiments, the first elastic member 6A or the second elastic member 9A can also be connected between the mass plate and the base layer in other structural forms of the chip body 502 to improve the in-plane torsional stiffness of the mass plate in other chip bodies 502. For example, the first elastic member 6A or the second elastic member 9A is connected between Figure 8 The chip body shown is between the quality plate 1 and the base layer 5021 to improve Figure 8 The in-plane torsional stiffness of the mass plate 1 in the chip body 502 is shown. For example, the first elastic member 6A or the second elastic member 9A is connected to Figure 10 The chip body shown is between the quality plate 1 and the base layer 5021 to improve Figure 10 The in-plane torsional stiffness of the mass plate 1 in the chip body 502 is not specifically limited in this application.

[0201] Then, in order to improve the signal-to-noise ratio of sensitive components, in some embodiments, see Figure 21 , Figure 21Schematic diagram of the cross-sectional structure of the chip body 502 provided for some other embodiments of the present application. In this embodiment, the base layer 5021 includes a first surface S1 and a second surface S2. The first surface S1 faces the first mass plate 1A, and the second surface S2 faces the first surface S1. The base layer 5021 is provided with at least one damping groove 00A recessed from the first surface S1 to the second surface S2. Specifically, the at least one damping groove 00A can be provided in the substrate layer 5021a, the device layer, the conductive layer or the insulating layer within the base layer 5021. The vertical projections of the first group of through holes 13A and the second group of through holes 13A on the first surface S1 are located within the at least one damping groove 00A. The dynamic viscosity of the gas in the sealed cavity is defined as μ, the length of the first mass plate 1A is l, the width is w, the distance between the first mass plate 1A and the base layer 5021 is h, and the relationship between the squeeze film damping c of the first mass plate 1A and μ, l, w, and h is shown in (1) below.

[0202]

[0203] As can be seen from expression (1), providing damping grooves 00A in the base layer 5021 increases the distance h between the first mass plate 1A and the base layer 5021, thereby reducing the squeeze-film damping c of the first mass plate 1A. A smaller squeeze-film damping c results in lower noise and a higher signal-to-noise ratio. Furthermore, providing damping grooves 00A increases the space for gas expansion between the first mass plate 1A and the base layer 5021, reducing the pressure differential caused by the temperature gradient in the Z-axis direction, thereby reducing temperature drift in the Z-axis direction to a certain extent.

[0204] In the above embodiment, the number of the damping groove 00A can be one or more, and the shape of the damping groove 00A can be a rectangular groove, a square groove, a triangular groove, a circular groove, an elliptical groove or a groove of an irregular shape, which is not specifically limited in this application.

[0205] In some embodiments, see Figure 22 , Figure 22 for Figure 21 A top view of a structure of the base layer 5021 in the chip body 502 is shown. In this embodiment, the at least one damping groove 00A includes a first damping groove 01A and a second damping groove 02A. The vertical projection of the first group of through holes 13A on the first surface S1 is located within the first damping groove 01A, and the vertical projection of the second group of through holes 13A on the first surface S1 is located within the second damping groove 02A. This reduces the area of ​​the damping grooves in the base layer 5021, which helps ensure the structural strength of the base layer 5021 and, therefore, the chip body 502.

[0206] In some other embodiments, see Figure 23 , Figure 23 for Figure 21 A top view of another structure of the base layer 5021 in the chip body 502 is shown. In this embodiment, the at least one damping groove 00A has only one damping groove 00A. The vertical projections of the first group of through holes 13A and the second group of through holes 13A on the first surface S1 are both located within the damping groove 00A. This allows for a simple shape of the base layer 5021 and facilitates processing.

[0207] In some embodiments, please refer back to Figure 21 The depth of the damping groove 00A is greater than or equal to 1 μm and less than or equal to 3 μm. Optionally, the depth of the damping groove 00A can be 1 μm, 2 μm, or 3 μm. In this way, the depth of the damping groove 00A is moderate, which can take into account both the signal-to-noise ratio and the structural strength of the base layer 5021.

[0208] In some embodiments, the damping groove 00A can be obtained by etching, which is a mature and easy-to-manufacture process.

[0209] Finally, in order to improve the sensitivity of the chip body 502, in some embodiments, refer to Figure 24 , Figure 24 A top view of the chip body 502, provided in yet other embodiments of the present application, after removing the signal processing component 5025 and the top cover 5024. In this embodiment, the chip body 502 also includes a second sensitive component 5023B. The second sensitive component 5023B is also disposed within the sealed cavity, with the first sensitive component 5023A and the second sensitive component 5023B spaced apart along the X-axis.

[0210] The second sensitive component 5023B may include a second mass plate 1B, a second anchor point 2B, a second torsion beam 3B, and a second detection electrode 4B.

[0211] The second mass plate 1B may be a conductive structure as a whole. For example, the material of the second mass plate 1B may be polysilicon or low-resistance single crystal silicon. The second mass plate 1B and the first mass plate 1A are arranged along the X-axis direction.

[0212] In some embodiments, the second mass plate 1B is substantially in the shape of a rectangular plate. Based on this, the width direction of the second mass plate 1B can also be consistent with the X-axis direction.

[0213] The second mass plate 1B is connected to the second anchor point 2B via a second torsion beam 3B. The second torsion beam 3B at least allows the second mass plate 1B to drive the second torsion beam 3B to rotate about the axis formed by the second torsion beam 3B and the second anchor point 2B, thereby enabling the second mass plate 1B to generate a seesaw-like motion. Optionally, the length of the second torsion beam 3B is parallel to that of the first torsion beam 3A.

[0214] Portions of the second mass plate 1B located on both sides of the second torsion beam 3B are defined as a third mass portion 11B and a fourth mass portion 12B, respectively.

[0215] Based on this, at least one of the third mass portion 11B and the fourth mass portion 12B is provided with a through hole 13B. Through hole 13B can be a comb-tooth hole, a damping hole, or a through hole with another function. This application uses through hole 13B as a comb-tooth hole for illustrative purposes. The total area of ​​through holes 13B in the third mass portion 11B is less than the total area of ​​through holes 13B in the fourth mass portion 12B.

[0216] Also, see Figure 24 The outer contours of the third mass portion 11B and the fourth mass portion 12B are symmetrically arranged about the second torsion beam 3B. The outer contours of the third mass portion 11B and the fourth mass portion 12B refer to the outer edge contours of the third mass portion 11B and the outer edge contours of the fourth mass portion 12B, respectively, after ignoring the thickness of the third mass portion 11B and assuming the third mass portion 11B is equivalent to a planar structure.

[0217] In this way, the second sensitive component has the same structural form as the first sensitive component, which can also reduce the impact of temperature differences in the height direction, reduce temperature drift, and improve the detection accuracy of the accelerometer. At the same time, by providing two sensitive components, the Z-axis and Y-axis of each sensitive component share the same mass plate, and the Z-axis mass plate and the Y-axis mass plate are not separately provided. Given a certain size of the chip body 502, the area and mass of the Z-axis mass plate (equal to the area and mass of the mass plate) can be designed to be larger, and the area and mass of the Y-axis mass plate (equal to the area and mass of the mass plate) can also be designed to be larger. This can improve the detection sensitivity of the bone vibration signal components in the Z-axis and Y-axis directions. Furthermore, given a certain size of the chip body 502, by providing two sensitive components, the area of ​​the mass plate within a single sensitive component can be reduced, thereby reducing the impact force of the mass plate on the side frame when torsion occurs in-plane, and reducing the risk of the mass plate damaging the side frame or the retaining structure when torsion occurs in-plane, thereby improving reliability. Because the mass plate within a single sensitive component has a smaller area and relatively smaller mass, it has a higher natural frequency and can pick up high-frequency vibration signals, thus ensuring bandwidth.

[0218] In some embodiments, please refer to Figure 24The direction in which the first mass portion 11A points toward the second mass portion 12A can be opposite to the direction in which the third mass portion 11B points toward the fourth mass portion 12B. The direction in which the first mass portion 11A points toward the second mass portion 12A refers to the direction in which the geometric center of the area enclosed by the outer contour of the first mass portion 11A points toward the geometric center of the area enclosed by the outer contour of the second mass portion 12A, ignoring the thickness of the first mass plate 1A. Similarly, the direction in which the third mass portion 11B points toward the fourth mass portion 12B refers to the direction in which the geometric center of the area enclosed by the outer contour of the third mass portion 11B points toward the geometric center of the area enclosed by the outer contour of the fourth mass portion 12B, ignoring the thickness of the second mass plate 1B. This arrangement of the two mass plates in opposite directions can suppress temperature drift along the Y-axis.

[0219] An elastic member may also be provided in the second sensitive component 5023B to prevent the second mass plate 1B from twisting in the plane.

[0220] In some embodiments, see Figure 25 , Figure 25 This is a top view of the chip body 502 provided in yet other embodiments of the present application, after removing the signal processing component 5025 and the top cover 5024. In this embodiment, the second sensitive component 5023B further includes a third elastic member 6B. The third elastic member 6B is connected between the end of the third mass portion 11B facing away from the fourth mass portion 12B and the base layer 5021. The structure of the third elastic member 6B can be the same as that of the first elastic member 6A described in any of the aforementioned embodiments, and will not be further described here.

[0221] In some other embodiments, see Figure 26 , Figure 26 This is a top view of the chip body 502 provided in yet other embodiments of the present application, with the signal processing component 5025 and top cover 5024 removed. In this embodiment, the second sensitive component 5023B further includes a fourth elastic member 9B. The fourth elastic member 9B is connected between the end of the fourth mass portion 12B facing away from the third mass portion 11B and the base layer 5021. The structure of the fourth elastic member 9B can also be the same as that of the first elastic member 6A described in any of the aforementioned embodiments, and will not be further described here.

[0222] In some other embodiments, the second sensitive component 5023B is provided with a third elastic member 6B and a fourth elastic member 9B to increase the in-plane torsional stiffness of the second mass plate 1B.

[0223] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0224] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. An accelerometer, characterized in that include: basal layer; a first anchor point, the first anchor point being fixed to the base layer; A first mass plate, wherein the first mass plate is connected to the first anchor point by means of a first torsion beam, and the parts of the first mass plate located on both sides of the first torsion beam are respectively a first mass part and a second mass part; at least one of the first mass part and the second mass part is provided with a through hole, and the sum of the areas of the through holes on the first mass part is smaller than the sum of the areas of the through holes on the second mass part, and the outer contour of the first mass part and the outer contour of the second mass part are symmetrically arranged with respect to the first torsion beam.

2. The accelerometer according to claim 1, wherein Also includes: a first Z-axis detection electrode and a second Z-axis detection electrode, wherein the first Z-axis detection electrode and the second Z-axis detection electrode are arranged on the base layer, and along a direction perpendicular to the base layer, the first Z-axis detection electrode is opposite to at least a portion of the first mass portion, and the second Z-axis detection electrode is opposite to at least a portion of the second mass portion.

3. The accelerometer according to claim 2, wherein: There are multiple through holes, and the multiple through holes form two groups of through holes, and the two groups of through holes are respectively a first group of through holes and a second group of through holes; The first set of through holes is provided in the first mass portion, and the second set of through holes is provided in the second mass portion; The vertical projection area of ​​each through hole in the first group of through holes on the base layer is equal to the vertical projection area of ​​each through hole in the second group of through holes on the base layer, and the number of through holes in the first group of through holes is less than the number of through holes in the second group of through holes.

4. The accelerometer according to claim 3, wherein: The first mass portion includes a first mass sub-portion and a second mass sub-portion; along a direction perpendicular to the base layer, the first Z-axis detection electrode is opposite to the first mass sub-portion, and the first group of through holes is provided in the second mass sub-portion; The second mass portion includes a third mass sub-portion and a fourth mass sub-portion. Along a direction perpendicular to the base layer, the second Z-axis detection electrode is opposite to the third mass sub-portion. The second group of through holes is provided in the fourth mass sub-portion.

5. The accelerometer according to claim 4, wherein: The first mass sub-portion is located on a side of the second mass sub-portion facing away from the first torsion beam, and the third mass sub-portion is located on a side of the fourth mass sub-portion facing away from the first torsion beam.

6. The accelerometer according to any one of claims 1 to 5, characterized in that: Also includes: a Y-axis detection electrode, the Y-axis detection electrode being disposed on the base layer; A comb tooth assembly, the comb tooth assembly including fixed teeth and movable teeth, the fixed teeth being fixed to the base layer and being electrically conductive with the Y-axis detection electrode, the ends of the fixed teeth facing away from the base layer being accommodated in the through holes, the movable teeth being arranged on the first mass plate, the fixed teeth and the movable teeth being spaced apart in a direction parallel to the base layer and perpendicular to the first torsion beam.

7. The accelerometer according to any one of claims 1 to 6, characterized in that: Also includes: The first elastic member is located on a side of the first mass portion facing away from the second mass portion, and one end of the first elastic member is connected to the first mass portion, and the other end is fixed relative to the base layer.

8. The accelerometer according to claim 7, wherein: Also includes: a first fixing portion and a second fixing portion, wherein the first fixing portion is arranged at the end of the first mass portion facing away from the second mass portion, the second fixing portion is located on a side of the first fixing portion facing away from the first mass portion, and the second fixing portion is fixed relative to the base layer, and the first elastic member is connected between the first fixing portion and the second fixing portion.

9. The accelerometer according to claim 7 or 8, characterized in that The first elastic member includes at least one elastic arm; Each elastic arm includes a plurality of first elastic arm segments and at least one second elastic arm segment; Each first elastic arm segment extends along the length direction of the first torsion beam, the plurality of first elastic arm segments are arranged in a direction parallel to the base layer and perpendicular to the first torsion beam, and a gap is formed between two adjacent first elastic arm segments; The plurality of first elastic arm sections are alternately connected to the at least one second elastic arm section in sequence.

10. The accelerometer according to claim 9, wherein: Of two adjacent first elastic arm segments, two ends of one first elastic arm segment are respectively a first end and a second end, and two ends of the other first elastic arm segment are respectively a third end and a fourth end; The direction in which the first end points to the second end is the same as the direction in which the third end points to the fourth end; The second elastic arm section between the two adjacent first elastic arm sections is connected between the second end and the fourth end.

11. The accelerometer according to claim 9, wherein: Of two adjacent first elastic arm segments, two ends of one first elastic arm segment are respectively a first end and a second end, and two ends of the other first elastic arm segment are respectively a third end and a fourth end; The direction in which the first end points to the second end is the same as the direction in which the third end points to the fourth end; The second elastic arm section between the two adjacent first elastic arm sections is connected between the second end and the third end.

12. The accelerometer according to any one of claims 9 to 11, characterized in that: There are two elastic arms, and the two elastic arms are respectively located on both sides of the first axis and are symmetrically arranged about the first axis; The first axis is parallel to the first mass plate, passes through the midpoint of the length direction of the first torsion beam, and is perpendicular to the length direction of the first torsion beam.

13. The accelerometer according to any one of claims 9 to 12, characterized in that: The width of the first elastic arm section is less than or equal to the width of the first torsion beam.

14. The accelerometer according to any one of claims 9 to 13, characterized in that: The width of the gap between two adjacent first elastic arm sections is 2-5 times the width of the first elastic arm section.

15. The accelerometer according to any one of claims 9 to 14, characterized in that: A dimension of the first elastic member along a length direction of the first torsion beam is smaller than or equal to a dimension of the first mass plate along the length direction of the first torsion beam.

16. The accelerometer according to any one of claims 3 to 5, characterized in that: The base layer has a first surface facing the mass plate and a second surface facing away from the mass plate; The base layer is provided with at least one damping groove recessed from the first surface to the second surface, and vertical projections of the first group of through holes and the second group of through holes on the base layer are located within the at least one damping groove.

17. The accelerometer according to claim 16, wherein: The at least one damping groove includes a first damping groove and a second damping groove; The vertical projection of the first group of through holes on the base layer is located in the first damping groove, and the vertical projection of the second group of through holes on the base layer is located in the second damping groove.

18. The accelerometer according to claim 16, wherein: The number of the at least one damping groove is one, and vertical projections of the first group of through holes and the second group of through holes on the base layer are both located within the damping groove.

19. The accelerometer according to any one of claims 16 to 18, characterized in that: The depth of the damping groove is greater than or equal to 1 μm and less than or equal to 3 μm.

20. The accelerometer according to any one of claims 1 to 19, wherein: Also includes: a second anchor point, the second anchor point being fixed to the base layer; a second mass plate, the second mass plate being connected to the second anchor point via a second torsion beam, and portions of the second mass plate located on either side of the second torsion beam constituting a third mass portion and a fourth mass portion, respectively; at least one of the third mass portion and the fourth mass portion being provided with a through hole, the sum of the areas of the through holes on the third mass portion being smaller than the sum of the areas of the through holes on the fourth mass portion, and an outer contour of the third mass portion being symmetrically arranged with respect to the second torsion beam; The second mass plate and the first mass plate are arranged along a length direction of the first torsion beam, and the length direction of the second torsion beam is parallel to the length direction of the first torsion beam.

21. The accelerometer according to claim 20, wherein: The direction in which the first mass portion points to the second mass portion is opposite to the direction in which the third mass portion points to the fourth mass portion.

22. An accelerometer, characterized in that: include: basal layer; a first anchor point, the first anchor point being fixed to the base layer; a first mass plate, wherein the first mass plate is connected to the first anchor point via a first torsion beam, and portions of the first mass plate located on both sides of the first torsion beam are respectively a first mass portion and a second mass portion; The first elastic member is located on a side of the first mass portion facing away from the second mass portion, and one end of the first elastic member is connected to the first mass portion, and the other end is fixed relative to the base layer.

23. The accelerometer according to claim 22, wherein: Also includes: a first fixing portion and a second fixing portion, wherein the first fixing portion is arranged at the end of the first mass portion facing away from the second mass portion, the second fixing portion is located on a side of the first fixing portion facing away from the first mass portion, and the second fixing portion is fixed relative to the base layer, and the first elastic member is connected between the first fixing portion and the second fixing portion.

24. The accelerometer according to claim 22 or 23, characterized in that The first elastic member includes at least one elastic arm; Each elastic arm includes a plurality of first elastic arm segments and at least one second elastic arm segment; Each first elastic arm segment extends along the length direction of the first torsion beam, the plurality of first elastic arm segments are arranged in a direction parallel to the base layer and perpendicular to the first torsion beam, and a gap is formed between two adjacent first elastic arm segments; The plurality of first elastic arm sections are alternately connected to the at least one second elastic arm section in sequence.

25. The accelerometer according to claim 24, wherein: Of two adjacent first elastic arm segments, two ends of one first elastic arm segment are respectively a first end and a second end, and two ends of the other first elastic arm segment are respectively a third end and a fourth end; The direction in which the first end points to the second end is the same as the direction in which the third end points to the fourth end; The second elastic arm section between the two adjacent first elastic arm sections is connected between the second end and the fourth end.

26. The accelerometer according to claim 24, wherein: Of two adjacent first elastic arm segments, two ends of one first elastic arm segment are respectively a first end and a second end, and two ends of the other first elastic arm segment are respectively a third end and a fourth end; The direction in which the first end points to the second end is the same as the direction in which the third end points to the fourth end; The second elastic arm section between the two adjacent first elastic arm sections is connected between the second end and the third end.

27. The accelerometer according to any one of claims 24 to 26, characterized in that: There are two elastic arms, and the two elastic arms are respectively located on both sides of the first axis and are symmetrically arranged about the first axis; The first axis is parallel to the first mass plate, passes through the midpoint of the length direction of the first torsion beam, and is perpendicular to the length direction of the first torsion beam.

28. The accelerometer according to any one of claims 24 to 27, characterized in that The width of the first elastic arm section is smaller than the width of the first torsion beam.

29. The accelerometer according to any one of claims 24 to 28, wherein: The width of the gap between two adjacent first elastic arm sections is 2-5 times the width of the first elastic arm section.

30. An electronic device, characterized in that: include: shell; The accelerometer according to any one of claims 1 to 29, wherein the accelerometer is disposed in the housing.

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