CN117907633A - Acceleration sensor - Google Patents

Abstract

The invention provides an acceleration sensor, which comprises a substrate, a first anchor point, an inner side mass unit, an outer side mass unit, a first teeter-totter unit, a second teeter-totter unit, a first acceleration detection unit and a second acceleration detection unit, wherein the first anchor point is arranged on the substrate; the first anchor point is fixed in the middle of the substrate; the inboard mass element encircling an outboard side of the first anchor point, the outboard mass element encircling an outboard side of the inboard mass element; the first seesaw unit and the second seesaw unit are arranged opposite to each other, and the first seesaw unit and the second seesaw unit are enclosed to form an annular structure; the annular structure surrounds the outside of the outside mass unit; at least part of the first acceleration detection unit is arranged on the annular structure and is used for detecting acceleration along the out-of-plane Z-axis direction; the second acceleration detection unit is arranged on the outer side mass unit and is used for detecting acceleration along the X-axis direction in the plane and the Y-axis direction in the plane. The invention has the technical effects of reasonable design and higher sensitivity.

Description

Acceleration sensor

Technical Field

The invention belongs to the technical field of sensors, and particularly relates to an acceleration sensor.

Background

The acceleration sensor comprises one or more proof masses for detecting acceleration. For example, some acceleration sensors include a proof mass configured to move in a plane to detect acceleration in the plane of the proof mass, and the proof mass is configured to move out of the plane to detect acceleration perpendicular to the plane of the proof mass. Acceleration may be detected using a capacitive sensor coupled to the proof mass.

The existing acceleration sensor has the technical problems of low sensitivity and low space utilization rate.

Disclosure of Invention

The invention aims to at least solve one of the technical problems in the prior art and provides a novel technical scheme of an acceleration sensor.

According to an aspect of the present invention, there is provided an acceleration sensor including:

the device comprises a substrate and a first anchor point, wherein the first anchor point is fixed in the middle of the substrate;

An inner mass unit surrounding and elastically connected to the outside of the first anchor point, and an outer mass unit surrounding and elastically connected to the outside of the inner mass unit;

the device comprises a first seesaw unit and a second seesaw unit, wherein the first seesaw unit and the second seesaw unit are oppositely arranged, and the first seesaw unit and the second seesaw unit are enclosed to form an annular structure; the annular structure surrounds the outer side of the outer side mass unit and is elastically connected with the outer side mass unit;

The first acceleration detection unit and the second acceleration detection unit are arranged on the annular structure, and are used for detecting acceleration along the out-of-plane Z-axis direction; the second acceleration detection unit is arranged on the outer side mass unit and is used for detecting acceleration along the in-plane X-axis direction and the in-plane Y-axis direction;

the out-of-plane Z-axis direction, the in-plane X-axis direction and the in-plane Y-axis direction are perpendicular to each other.

Optionally, the acceleration sensor further includes a first elastic member and a second elastic member; the extending direction of the first elastic piece is perpendicular to the extending direction of the second elastic piece;

The inner mass unit is elastically connected with the first anchor point through the first elastic piece; the outer side mass unit is elastically connected with the inner side mass unit through the second elastic piece.

Optionally, the first elastic piece is an X-axis single-degree-of-freedom spring, and the second elastic piece is a Y-axis single-degree-of-freedom spring;

Or the first elastic piece is a Y-axis single-degree-of-freedom spring, and the second elastic piece is an X-axis single-degree-of-freedom spring.

Optionally, the X-axis single-degree-of-freedom spring is serpentine and/or U-shaped;

the Y-axis single-degree-of-freedom spring is serpentine and/or U-shaped.

Optionally, the second acceleration detection unit includes an X-axis detection capacitor set and a Y-axis detection capacitor set disposed on the outer mass unit;

The X-axis detection capacitor groups are symmetrically arranged along an in-plane X-axis, and the X-axis detection capacitor groups are symmetrically arranged along an in-plane Y-axis; the X-axis detection capacitor group is used for detecting acceleration along the X-axis direction in the plane;

The Y-axis detection capacitor groups are symmetrically arranged along an in-plane Y-axis, and the Y-axis detection capacitor groups are symmetrically arranged along an in-plane X-axis; the Y-axis detection capacitor group is used for detecting acceleration along the Y-axis direction in the plane.

Optionally, the X-axis detection capacitor group includes a movable capacitor plate disposed on a sidewall of the outer mass unit, and a first fixed capacitor plate and a second fixed capacitor plate fixed on the substrate; the first fixed capacitor plates and the second fixed capacitor plates are arranged in parallel and at intervals, and are distributed along the Y-axis direction in the plane;

the first fixed capacitor plate and the second fixed capacitor plate are respectively arranged in a differential mode with the movable capacitor plate on the side wall of the outer side quality unit.

Optionally, the X-axis detection capacitor group includes a first movable comb-tooth type capacitor plate disposed on the outer mass unit and a first fixed comb-tooth type capacitor plate fixed on the substrate;

the first movable comb-tooth type capacitor electrode plates distributed along the X-axis direction in the plane and the first fixed comb-tooth type capacitor electrode plates are matched to form a first comb-tooth type capacitor.

Optionally, the Y-axis detection capacitor group includes a movable electrode disposed on a sidewall of the outer mass unit, a third fixed capacitor plate fixed on the substrate, and a fourth fixed capacitor plate; the third fixed capacitor plate and the fourth fixed capacitor plate are parallel and are arranged at intervals;

the third fixed capacitor plate and the fourth fixed capacitor plate are respectively arranged in a differential mode with the movable electrode on the side wall of the outer side quality unit.

Optionally, the Y-axis detection capacitor group includes a second movable comb-tooth type capacitor plate disposed on the outer side mass unit and a second fixed comb-tooth type capacitor plate fixed on the substrate;

The second movable comb-tooth type capacitor electrode plates distributed along the Y-axis direction in the plane are matched with the second fixed comb-tooth type capacitor electrode plates to form a second comb-tooth type capacitor.

Optionally, the first fixed comb-tooth type capacitor plate is fixed on the substrate through a second anchor point; the second fixed comb-tooth type capacitor polar plate is fixed on the substrate through a third anchor point;

The second anchor point and the third anchor point are both near the first anchor point.

Optionally, the first seesaw unit is elastically connected with one end of the outer side mass unit, and the second seesaw unit is elastically connected with the other end of the outer side mass unit; the first seesaw units and the second seesaw units are symmetrically distributed along the symmetry axis of the acceleration sensor respectively; the first teeterboard units respectively form two first teeterboard structures on two sides of the symmetry axis, and the two first teeterboard structures rotate along the first rotation axis; the second seesaw units respectively form two second seesaw structures on two sides of the symmetrical shaft, and the two second seesaw structures rotate along a second rotating shaft; the first rotating shaft and the second rotating shaft are distributed along the Y-axis direction in the plane, and the symmetrical shafts are distributed along the X-axis direction in the plane.

Optionally, the acceleration sensor further comprises a coupling beam;

Part of the second seesaw units are sleeved on the outer sides of part of the first seesaw units to form a nested structure, the coupling beams are located in the nested structure, one ends of the coupling beams are connected with the first seesaw units, and the other ends of the coupling beams are connected with the second seesaw units.

The invention has the technical effects that:

In the embodiment of the application, the acceleration sensor is reasonable in design, and the detection mass in the out-of-plane Z-axis direction is arranged in the annular structure; the detection mass in the X-axis direction in the plane at least comprises the detection mass arranged on the outer side mass unit and the detection mass arranged on the annular structure; meanwhile, the detection mass in the Y-axis direction in the plane at least comprises the detection mass arranged on the outer side mass unit and the detection mass arranged on the annular structure, and the layout of the common detection mass enables the acceleration sensor to have higher space utilization rate, so that the acceleration sensor has higher sensitivity under the same area.

Drawings

Fig. 1 is a schematic structural diagram of an acceleration sensor according to a first embodiment of the present invention;

fig. 2 is a schematic view of a detection mode of an in-plane X-axis direction of an acceleration sensor according to a first embodiment of the present invention;

FIG. 3 is a schematic view of a detection mode of an in-plane Y-axis direction of an acceleration sensor according to a first embodiment of the present invention;

FIG. 4 is a schematic diagram illustrating a detection mode of an out-of-plane Z-axis direction of an acceleration sensor according to a first embodiment of the present invention;

FIG. 5 is a schematic view of parasitic modes in the out-of-plane Z-axis direction of an acceleration sensor according to a first embodiment of the present invention;

fig. 6 is a schematic structural view of a coupling beam of an acceleration sensor according to a first embodiment of the present invention;

fig. 7 is a schematic structural diagram of an acceleration sensor according to a second embodiment of the present invention;

FIG. 8 is a schematic diagram illustrating a detection mode of an in-plane X-axis direction of an acceleration sensor according to a second embodiment of the present invention;

FIG. 9 is a schematic view of a detection mode of an in-plane Y-axis direction of an acceleration sensor according to a second embodiment of the present invention;

FIG. 10 is a schematic view of a detection mode of an out-of-plane Z-axis direction of an acceleration sensor according to a second embodiment of the present invention;

FIG. 11 is a schematic view of parasitic modes in the out-of-plane Z-axis direction of an acceleration sensor according to a second embodiment of the present invention;

Fig. 12 is a schematic structural view of a coupling beam of an acceleration sensor according to a second embodiment of the present invention;

fig. 13 is a schematic structural view of an acceleration sensor according to a third embodiment of the present invention;

Fig. 14 is a schematic view of a detection mode of an in-plane X-axis direction of an acceleration sensor according to a third embodiment of the present invention;

FIG. 15 is a schematic view of a detection mode of an in-plane Y-axis direction of an acceleration sensor according to a third embodiment of the present invention;

FIG. 16 is a schematic view of a detection mode of an out-of-plane Z-axis direction of an acceleration sensor according to a third embodiment of the present invention;

FIG. 17 is a schematic view of parasitic modes in the out-of-plane Z-axis direction of an acceleration sensor according to a third embodiment of the present invention;

Fig. 18 is a schematic structural view of a coupling beam of an acceleration sensor according to a third embodiment of the present invention;

FIG. 19 is a schematic diagram showing the structure of an X-axis detection capacitor set and a Y-axis detection capacitor set in an acceleration sensor according to a third embodiment of the present invention;

FIG. 20 is a schematic structural diagram of an X-axis detecting capacitor set in an acceleration sensor according to a first embodiment and a second embodiment of the present invention;

fig. 21 is a schematic structural diagram of a Y-axis detection capacitor set in an acceleration sensor according to a first embodiment and a second embodiment of the present invention.

In the figure: 100. a symmetry axis; 200. a first rotating shaft; 300. a second rotating shaft; 1. an inner mass unit; 2. an outer mass unit; 31. a first anchor point; 32. a second anchor point; 33. a third anchor point; 4. a first seesaw unit; 5. a second seesaw unit; 6. a first acceleration detection unit; 71. an X-axis detection capacitor group; 711. a first through hole; 712. a first fixed capacitor plate; 713. a second fixed capacitor plate; 714. a first fixed comb-tooth type capacitor plate; 715. a first movable comb-tooth type capacitor plate; 72. a Y-axis detection capacitor group; 721. a second through hole; 722. a third fixed capacitor plate; 723. a fourth fixed capacitor plate; 724. a second fixed comb-tooth type capacitor plate; 725. a second movable comb-tooth type capacitor plate; 81. a first elastic member; 82. a second elastic member; 9. a coupling beam; 10. a first out-of-plane proof mass; 11. and detecting the quality outside the second surface.

Detailed Description

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

Reference will now be made in detail to embodiments of the present application, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements throughout or elements having like or similar functionality. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

The features of the application "first", "second" and the like in the description and in the claims may be used for the explicit or implicit inclusion of one or more such features. In the description of the present application, unless otherwise indicated, the meaning of "a plurality" is two or more. Furthermore, in the description and claims, "and/or" means at least one of the connected objects, and the character "/", generally means that the associated object is an "or" relationship.

In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present application and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present application.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application will be understood in specific cases by those of ordinary skill in the art.

Example 1

Referring to fig. 1 to 6, according to an aspect of the present invention, there is provided an acceleration sensor. For convenience in explaining the acceleration sensor, an X-Y-Z axis three-dimensional coordinate system is established, and an in-plane X axis direction, an in-plane Y axis direction and an out-of-plane Z axis direction are defined to be perpendicular to each other.

Specifically, the acceleration sensor includes a base, a first anchor point 31, an inner mass unit 1, an outer mass unit 2, a first teeter-totter unit 4, a second teeter-totter unit 5, a first acceleration detection unit 6, and a second acceleration detection unit.

Illustratively, the two first anchor points 31 are symmetrically distributed along the in-plane X-axis.

Further specifically, the first anchor point 31 is fixed to the middle of the substrate; the inner mass unit 1 surrounds the outer side of the first anchor point 31 and is elastically connected with the first anchor point 31, and the outer mass unit 2 surrounds the outer side of the inner mass unit 1 and is elastically connected with the inner mass unit 1; the first seesaw unit 4 and the second seesaw unit 5 are arranged opposite to each other, and the two units are enclosed to form an annular structure; the ring-shaped structure surrounds the outside of the outside mass unit 2 and is elastically connected with the outside mass unit 2, for example, the ring-shaped structure surrounds and is elastically connected with the outside mass unit 2 by a torsion spring; at least part of the first acceleration detection unit 6 is arranged on the annular structure and is used for detecting acceleration along the out-of-plane Z-axis direction; a second acceleration detection unit is provided to the outer mass unit 2 for detecting acceleration in the in-plane X-axis direction and in-plane Y-axis direction. The out-of-plane Z-axis direction, the in-plane X-axis direction and the in-plane Y-axis direction are perpendicular to each other.

The first acceleration detection unit 6 is used for detecting seesaw rotation caused by movement of the inspection mass on the annular structure formed by the encircling of the first seesaw unit 4 and the second seesaw unit 5 along the out-of-plane Z-axis direction caused by the surface external acceleration, and the second acceleration detection unit is used for detecting translation caused by movement of the inspection mass on the outer side mass unit 2 along the in-plane X-axis direction and the in-plane Y-axis direction caused by the in-plane acceleration.

In the embodiment of the application, the acceleration sensor is reasonable in design, and the detection mass in the out-of-plane Z-axis direction is arranged in the annular structure; the detection mass in the X-axis direction in the plane at least comprises the detection mass arranged on the outer side mass unit 2 and the detection mass arranged on the annular structure; meanwhile, the detection mass in the in-plane Y-axis direction at least comprises the detection mass arranged on the outer side mass unit 2 and the detection mass arranged on the annular structure, and the layout of the common detection mass enables the acceleration sensor to have higher space utilization rate, so that the acceleration sensor has higher sensitivity under the same area.

It should be noted that, the annular structure formed by enclosing the first seesaw unit 4 and the second seesaw unit 5 is elastically connected to the outer side mass unit 2, so as to provide support for the proof mass on the annular structure when it moves linearly along the in-plane X-axis direction and the in-plane Y-axis direction. At the same time, the outer mass unit 2 is elastically connected to the inner mass unit 1, and the inner mass unit 1 is elastically connected to the first anchor point 31. For example, the outer mass unit and the inner mass unit are connected by a second elastic connecting piece, and the second elastic connecting piece is parallel to the in-plane Y axis, so that the second elastic connecting piece provides flexible support for the outer mass unit and the annular structure (i.e., the first seesaw unit and the second seesaw unit) to move along the in-plane X axis direction, at this time, the first elastic connecting piece of the elastic connection between the inner mass unit (mass unit) and the first anchor point is parallel to the in-plane X axis, and the first elastic connecting piece provides flexible support for the inner mass unit, the outer mass unit and the annular structure to move along the in-plane Y axis direction.

For another example, the outer mass unit and the inner mass unit are connected by a second elastic connecting piece, and the second elastic connecting piece is parallel to the in-plane X axis, so that the second elastic connecting piece provides flexible support for the outer mass unit and the annular structure (i.e., the first seesaw unit and the second seesaw unit) to move along the in-plane Y axis direction, at this time, the first elastic connecting piece elastically connected between the inner mass unit (mass unit) and the first anchor point is parallel to the in-plane Y axis, and the first elastic connecting piece provides flexible support for the inner mass unit, the outer mass unit and the annular structure to move along the in-plane X axis direction.

Illustratively, the acceleration sensors are symmetrically distributed along their symmetry axis 100; and the first seesaw unit 4 and the second seesaw unit 5 are symmetrically distributed along the symmetry axis 100.

Optionally, the acceleration sensor further includes a first elastic member 81 and a second elastic member 82; the extending direction of the first elastic member 81 is perpendicular to the extending direction of the second elastic member 82;

The inner mass unit 1 is elastically connected with the first anchor point 31 through the first elastic member 81; the outer mass unit 2 is elastically connected to the inner mass unit 1 through the second elastic member 82. This makes the connection between the outer mass unit 2, the inner mass unit 1, and the first anchor point 31 relatively simple, and helps to realize movement of the second acceleration detection unit on the outer mass unit 2 in the in-plane X-axis direction and the in-plane Y-axis direction, and further helps the acceleration sensor to realize detection of acceleration in the in-plane X-axis direction and the in-plane Y-axis direction.

In the embodiment of the application, the first anchor point 31 is arranged in the center of the structure of the acceleration sensor, and the annular structure formed by the surrounding of the inner side mass unit 1, the outer side mass unit 2, the first seesaw unit 4 and the second seesaw unit 5 shares the first anchor point 31 through the first elastic piece 81 and the second elastic piece 82, so that the integral structure of the acceleration sensor is less influenced by factors such as stress, and the anti-interference capability of the acceleration sensor is obviously improved.

Optionally, the first elastic member 81 is an X-axis single-degree-of-freedom spring, and the second elastic member 82 is a Y-axis single-degree-of-freedom spring. The anchor point, the detection quality of the outer mass unit 2, and the detection quality of the inner mass unit 1 may be set according to the layout requirement of the substrate, which is not limited in the present application.

In the above embodiment, the inspection mass in the in-plane X-axis direction includes the inspection mass provided to the outer mass unit 2, the inspection mass provided to the inner mass unit 1, and the inspection mass provided to the annular structure. The inspection quality in the in-plane Y-axis direction comprises the inspection quality arranged on the outer side quality unit 2 and the inspection quality arranged on the annular structure, and the layout of the common inspection quality is beneficial to further enabling the accelerometer to have higher sensitivity and higher space utilization rate under the same area.

Optionally, the X-axis single degree of freedom spring is serpentine; the Y-axis single-degree-of-freedom spring is in a snake shape. The X-axis single-degree-of-freedom spring and the Y-axis single-degree-of-freedom spring are reasonable in structural design, and are beneficial to achieving movement of the inspection mass on the outer side mass unit 2 along the in-plane X-axis direction and the in-plane Y-axis direction.

Alternatively, the second acceleration detection unit includes an X-axis detection capacitance group 71 and a Y-axis detection capacitance group 72 provided on the outer mass unit 2;

The X-axis detection capacitor groups 71 are symmetrically arranged along an in-plane X-axis, and the X-axis detection capacitor groups 71 are symmetrically arranged along an in-plane Y-axis; the X-axis detection capacitor group 71 is used for detecting acceleration along the in-plane X-axis direction;

the Y-axis detection capacitor groups 72 are symmetrically arranged along an in-plane Y-axis, and the Y-axis detection capacitor groups 72 are symmetrically arranged along an in-plane X-axis; the Y-axis detection capacitor group 72 is used to detect acceleration in the in-plane Y-axis direction.

In the above embodiment, the second acceleration detection unit has a reasonable structural design, which is helpful for accurately detecting the acceleration along the in-plane X-axis direction and the in-plane Y-axis direction.

Alternatively, referring to fig. 20, the x-axis detection capacitor group 71 includes a movable capacitor plate disposed on the sidewall of the outer mass unit, and a first fixed capacitor plate 712 and a second fixed capacitor plate 713 fixed on the substrate; the first fixed capacitor plates 712 and the second fixed capacitor plates 713 are parallel and spaced apart, and the first fixed capacitor plates 712 and the second fixed capacitor plates 713 are distributed along the in-plane Y-axis direction;

The first fixed capacitor plate 712 and the second fixed capacitor plate 713 are respectively differentially arranged from the movable capacitor plate of the outer side wall of the mass unit.

For example, a first through hole 711 penetrating to the substrate is provided on the outer side mass unit 2, the first fixed capacitor plate 712 and the second fixed capacitor plate 713 are both disposed in the first through hole 711, and a movable capacitor plate is disposed on a sidewall (i.e., a sidewall of the first through hole) of a corresponding position of the outer side mass unit.

When the outer mass unit 2 is displaced to the left by the acceleration to the left along the in-plane X-axis, the capacitance interval between the first differential detection capacitor formed by the first capacitor plate 712 and the movable capacitor plate on the side wall of the outer mass unit 2 increases, the capacitance interval between the second differential detection capacitor formed by the second capacitor plate 713 and the movable capacitor plate on the side wall of the outer mass unit 2 decreases, and the first differential detection capacitor and the second differential detection capacitor change in capacitance in proportion to the acceleration to the left along the in-plane X-axis, so that the real-time value of the acceleration to the left along the in-plane X-axis can be obtained by detecting the change in capacitance.

Similarly, when the outer mass unit 2 is displaced rightward by the rightward acceleration along the in-plane X-axis, a real-time value of the rightward acceleration along the in-plane X-axis can be obtained by detecting a change in the capacitance difference.

In the above embodiment, the structural design of the X-axis detection capacitor set 71 is reasonable, which is helpful for accurately detecting acceleration along the in-plane X-axis direction.

Alternatively, referring to fig. 21, the y-axis detection capacitor group 72 includes a movable electrode provided to the outer mass cell sidewall, a third fixed capacitor plate 722 fixed to the substrate, and a fourth fixed capacitor plate 723; wherein the third fixed capacitor plate 722 is parallel to and spaced apart from the fourth fixed capacitor plate 723;

The third fixed capacitor plate 722 and the fourth fixed capacitor plate 723 are respectively arranged differentially with the movable electrode of the lateral wall of the outer mass unit.

For example, the outer mass unit 2 is provided with a second through hole 721 penetrating to the substrate, the third fixed capacitor plate 722 and the fourth fixed capacitor plate 723 are both disposed in the second through hole 721, and the sidewall (i.e. the sidewall of the first through hole) of the corresponding position of the outer mass unit is provided with a movable capacitor plate.

When the outer mass unit 2 is displaced upward by the acceleration in the in-plane Y-axis direction, the capacitance interval between the third differential detection capacitor formed by the third capacitor plate 722 and the movable capacitor plate on the side wall of the outer mass unit 2 increases, the capacitance interval between the fourth differential detection capacitor formed by the fourth capacitor plate 723 and the movable capacitor plate on the side wall of the outer mass unit 2 decreases, and the third differential detection capacitor and the fourth differential detection capacitor change in capacitance in proportion to the acceleration in the in-plane Y-axis direction, so that the real-time value of the leftward acceleration in the in-plane Y-axis direction can be obtained by detecting the change in capacitance.

Similarly, when the second proof mass 721 is displaced downward by the acceleration downward along the in-plane Y-axis, a real-time value of the acceleration rightward along the in-plane Y-axis can be obtained by detecting a change in the capacitance.

In the above embodiment, the structure of the Y-axis detection capacitor set 72 is designed reasonably, which is helpful for accurately detecting the acceleration along the in-plane Y-axis direction.

Alternatively, the first seesaw unit 4 is elastically connected to one end of the outer side mass unit 2, and the second seesaw unit 5 is elastically connected to the other end of the outer side mass unit 2; the first seesaw unit 4 and the second seesaw unit 5 are symmetrically distributed along the symmetry axis 100 of the acceleration sensor respectively; the first teeter-totter units 4 respectively form two first teeter-totter structures on two sides of the symmetry axis 100, and the two first teeter-totter structures rotate along a first rotation axis 200; the second teeter-totter units 5 respectively form two second teeter-totter structures at two sides of the symmetry axis 100, and the two second teeter-totter structures rotate along the second rotation axis 300; the first rotating shaft 200 and the second rotating shaft 300 are both distributed along the in-plane Y-axis direction, and the symmetry axis 100 is distributed along the in-plane X-axis direction.

In the above embodiment, the first seesaw unit 4 and the second seesaw unit 5 are adopted as the detection structure of the surface external velocity, so that the first seesaw unit 4 and the second seesaw unit 5 can reversely rotate along the direction of the in-plane Y axis under the action of the acceleration in the out-of-plane Z axis direction, and the surface external velocity (i.e., the Z axis acceleration) of the acceleration sensor can be detected by the first acceleration detection unit 6 provided on the first seesaw unit 4 and the second seesaw unit 5. Meanwhile, when the two first teeter-totter structures or the two second teeter-totter structures are subjected to the action of unexpected Y-axis angular acceleration, the two first teeter-totter structures or the two second teeter-totter structures rotate in the same direction, and the capacitance change of the first acceleration detection unit 6 caused by the same-direction rotation is counteracted when the first acceleration detection unit 6 detects, so that the arrangement of the two first teeter-totter structures and the two second teeter-totter structures greatly reduces the influence of the Y-axis angular acceleration on the acceleration sensor, not only improves the cross inhibition ratio of the acceleration sensor, but also improves the accuracy of the acceleration sensor for detecting the applied speed.

Optionally, a first groove is provided on the outer side of the first seesaw unit 4, a second groove is provided on the inner side of the second seesaw unit 5, a part of the first seesaw unit 4 is embedded in the second groove, and a part of the second seesaw unit 5 is embedded in the first groove to form a nested structure, and the nested structure is located between the first rotating shaft 200 and the second rotating shaft 300.

In the above embodiment, the first seesaw unit 4 and the second seesaw unit 5 are nested. The nested structure helps to lengthen the rotating arms of the first and second seesaw units 4 and 5, and at the same time, the first acceleration detection unit 6 may be disposed in a region farther from the rotation axis, thereby making the gain of the surface applied speed detection larger.

Optionally, referring to fig. 7, the acceleration sensor further comprises a first out-of-plane proof mass 10 and a second out-of-plane proof mass 11;

Each of the first teeterboard structures comprises a first sub-rotating part and a second sub-rotating part, wherein the first sub-rotating part and the second sub-rotating part are respectively positioned at two opposite sides of the first rotating shaft 200, and a first groove is formed in the outer side of the second sub-rotating part; each second teeterboard structure comprises a third sub-rotating part and a fourth sub-rotating part, wherein the third sub-rotating part and the fourth sub-rotating part are respectively positioned at two opposite sides of the second rotating shaft 300, and a second groove is formed in the inner side of the third sub-rotating part; part of the second sub-rotating part is embedded in the second groove, and part of the third sub-rotating part is embedded in the first groove;

The first out-of-plane proof mass 10 is located in the first sub-rotation and the second out-of-plane proof mass 11 is located in the fourth sub-rotation.

In the above embodiment, the first out-of-plane detection mass 10 forms an asymmetric detection mass of the first seesaw unit, the second out-of-plane detection mass 11 forms an asymmetric detection mass of the second seesaw unit, and the first out-of-plane detection mass 10 and the second out-of-plane detection mass 11 are both located at the distal end of the seesaw structure, so that the first seesaw structure and the second seesaw structure are more sensitive to the applied velocity, and the gain detected by the acceleration sensor is further improved.

The first out-of-plane proof mass 10 is disposed at the position where the two first sub-rotating parts are connected, and the second out-of-plane proof mass 11 is disposed at the position where the two fourth sub-rotating parts are connected, which is helpful to further increase the distance between the proof mass and the rotating shaft, and make the first and second teeterboard structures more sensitive to the applied speed, so as to further increase the gain detected by the acceleration sensor.

Optionally, the acceleration sensor further comprises a coupling beam 9;

part of the second seesaw units 5 are sleeved on the outer sides of part of the first seesaw units 4 to form a nested structure, the coupling beams 9 are located in the nested structure, one ends of the coupling beams 9 are connected with the first seesaw units 4, and the other ends of the coupling beams 9 are connected with the second seesaw units 5.

In the above embodiment, by providing the coupling beam 9 between the first seesaw unit 4 and the second seesaw unit 5, the coupling beam 9 can weaken the co-rotation of the first seesaw unit 4 and the second seesaw unit 5, further suppress the influence of the angular acceleration of the y axis, and help to further improve the accuracy of the detection of the applied velocity across the acceleration sensor.

In a specific embodiment, the coupling beam 9 extends in a direction perpendicular to the symmetry axis 100, and one end of the coupling beam 9 is connected to the second sub-rotating part, and the other end is connected to the third sub-rotating part.

In a specific embodiment, the first sub-rotating portion, the second sub-rotating portion, the third sub-rotating portion, and the fourth sub-rotating portion are each provided with a first acceleration detecting unit 6, and a part of the first acceleration detecting unit 6 is located at a position of the first seesaw unit 4 away from the first rotating shaft 200, and a part of the first acceleration detecting unit 6 is located at a position of the second seesaw unit 5 away from the second rotating shaft 300. The plurality of first acceleration detection units 6 are symmetrically distributed along the symmetry axis 100.

The coupling beam 9 is, for example, strip-shaped, and one end of the coupling beam 9 is fixed to the bottom wall of the first recess and the other end is fixed to the bottom wall of the second recess. This makes the structure of the coupling beam 9 relatively simple, facilitating the assembly of the acceleration sensor.

In some embodiments, the coupling beam 9 comprises two mutually parallel sub-beams. One end of the sub beam is fixed on the bottom wall of the first groove, and the other end of the sub beam is fixed on the bottom wall of the second groove. This further improves the ability of the coupling beam 9 to weaken the co-rotation of the first and second see-saw units 4 and 5, thereby better suppressing the influence of the y-axis angular acceleration.

In other embodiments, the coupling beam 9 is in the shape of a rectangular ring. The middle part of one side of the coupling beam 9 is fixed on the inner side wall of the first groove, and the middle part of the other side of the coupling beam 9 is fixed on the inner side wall of the second groove. This makes the structural design of the coupling beam 9 reasonable, and can effectively weaken the ability of the first and second seesaw units 4 and 5 to rotate in the same direction.

In one embodiment, the first acceleration detection unit 6 includes a first off-plane detection capacitor plate and a second off-plane detection capacitor plate, where the first off-plane detection capacitor plate and the second off-plane detection capacitor plate are opposite and form a capacitor plate structure, the first off-plane detection capacitor plate is located on the substrate or the cavity cover, and the second off-plane detection capacitor plate is located on the first seesaw unit 4 and the second seesaw unit 5.

In this embodiment, the first acceleration detection unit 6 detects the acceleration along the out-of-plane Z-axis direction (i.e. the out-of-plane speed) so that the first seesaw unit 4 and the second seesaw unit 5 rotate in opposite directions, but in the parasitic mode, the first seesaw unit 4 and the second seesaw unit 5 rotate in the same direction around the Y-axis under the effect of the Y-axis angular acceleration, and in order to weaken the influence of the parasitic mode, the coupling beams 9 are connected to the first seesaw unit 4 and the second seesaw unit 5 to weaken the influence of the parasitic mode, that is, weaken the same rotation of the first seesaw unit 4 and the second seesaw unit 5 around the Y-axis, so that the cross suppression ratio of the accelerometer is further improved, and the accuracy of the detection of the acceleration sensor is remarkably improved. The parasitic mode, namely the acceleration sensor, is subjected to the acceleration action in the out-of-plane Z-axis direction and the acceleration action in the Y-axis angle.

Example 2

The present embodiment provides another acceleration sensor having substantially the same structure as that of embodiment 1, and only different parts will be described below.

Referring to fig. 7 to 12, the first elastic member 81 is a Y-axis single degree of freedom spring, and the second elastic member 82 is an X-axis single degree of freedom spring. The anchor point, the detection quality of the outer mass unit 2, and the detection quality of the inner mass unit 1 may be set according to the layout requirement of the substrate, which is not limited in the present application.

In the above embodiment, the inspection mass in the in-plane Y-axis direction includes the inspection mass provided to the outer mass unit 2, the inspection mass provided to the inner mass unit 1, and the inspection mass provided to the annular structure. The inspection quality in the in-plane X-axis direction comprises the inspection quality arranged on the outer side quality unit 2 and the inspection quality arranged on the annular structure, and the layout of the common inspection quality is beneficial to further enabling the accelerometer to have higher sensitivity and higher space utilization rate under the same area.

The X-axis single-degree-of-freedom spring and the Y-axis single-degree-of-freedom spring can be designed into different shapes according to the specific structure of the acceleration sensor, so that the detection of the in-plane Y-axis acceleration of the acceleration sensor can be better realized.

In the present embodiment, the two first anchor points 31 are symmetrically distributed along the symmetry axis 100.

Example 3

The present embodiment provides another acceleration sensor having substantially the same structure as that of embodiment 2, and only different parts will be described below.

Referring to fig. 13 to 18, alternatively, the X-axis single degree of freedom spring is U-shaped; the Y-axis single-degree-of-freedom spring is U-shaped.

In the embodiment, the X-axis single-degree-of-freedom spring and the Y-axis single-degree-of-freedom spring are U-shaped, so that cross coupling caused by the asymmetry of snakelike shape in the detection mode of the in-plane Y-axis direction of the acceleration sensor can be weakened, and the accuracy of the detection of the acceleration sensor can be improved.

Referring to fig. 19, optionally, the X-axis detection capacitor set 71 includes a first movable comb-type capacitor plate 715 disposed on the outer mass unit 2 and a first fixed comb-type capacitor plate 714 fixed on the substrate;

the first movable comb-tooth-type capacitor plates 715 and the first fixed comb-tooth-type capacitor plates 715 distributed along the in-plane X-axis direction cooperate to form a first comb-tooth-type capacitor.

The first fixed comb-tooth-shaped capacitor plate 714 includes a plurality of sub-capacitor plates distributed in an array along an in-plane X-axis direction. The sub-capacitor plates of the first movable comb-type capacitor plate 715 are positioned between two adjacent sub-capacitor plates of the first fixed comb-type capacitor plate 714.

When the outer mass unit 2 is displaced to the left by the acceleration along the in-plane X axis, the capacitance interval between the sub-capacitance plate of the first movable comb-tooth-shaped capacitance plate 715 and the fifth differential detection capacitance formed by the sub-capacitance plate of the first fixed comb-tooth-shaped capacitance plate 714 on one side thereof is reduced, the capacitance interval between the sub-capacitance plate of the first movable comb-tooth-shaped capacitance plate 715 on the other side symmetrical along the Y axis and the sixth differential detection capacitance formed by the sub-capacitance plate of the first fixed comb-tooth-shaped capacitance plate 714 on the other side thereof is increased, and the fifth differential detection capacitance and the sixth differential detection capacitance are changed in proportion to the acceleration to the left along the in-plane X axis, so that the real-time value of the acceleration to the left along the in-plane X axis can be obtained by detecting the change of the capacitance interval.

Similarly, when the outer mass unit 2 is displaced downward by the acceleration to the right along the in-plane X-axis, a real-time value of the acceleration to the right along the in-plane X-axis can be obtained by detecting a change in the capacitance difference.

Optionally, the Y-axis detection capacitor bank 72 includes a second movable comb capacitor plate 725 disposed on the outer mass unit 2 and a second fixed comb capacitor plate 724 fixed on the base;

The second movable comb-tooth-shaped capacitor plate 725 and the second fixed comb-tooth-shaped capacitor plate cooperate to form a second comb-tooth-shaped capacitor 724.

When the outer mass unit 2 is displaced upward by the acceleration in the Y-axis direction, the capacitance interval between the sub-capacitance plate of the second movable comb-tooth-shaped capacitance plate 725 and the seventh differential detection capacitance formed by the sub-capacitance plate of the second fixed comb-tooth-shaped capacitance plate 724 on one side thereof is reduced, the capacitance interval between the sub-capacitance plate of the second movable comb-tooth-shaped capacitance plate 725 and the eighth differential detection capacitance formed by the sub-capacitance plate of the second fixed comb-tooth-shaped capacitance plate 724 on the other side along the X-axis symmetry is increased, and the seventh differential detection capacitance and the eighth differential detection capacitance are changed in proportion to the acceleration in the Y-axis direction, so that the real-time value of the acceleration in the Y-axis direction can be obtained by detecting the change of the capacitance difference.

Similarly, when the outer mass unit 2 is displaced downward by the acceleration downward along the in-plane Y axis, a real-time value of the acceleration downward along the in-plane Y axis can be obtained by detecting a change in the capacitance difference.

In the above embodiment, the arrangement of the X-axis detection capacitor group 71 and the Y-axis detection capacitor group 72 is changed, so that the arrangement of the second acceleration detection unit is more flexible.

Optionally, a plurality of the first fixed comb-tooth capacitor plates 714 are each fixed to the substrate by a second anchor 32; a plurality of the second fixed comb-tooth-shaped capacitor plates 724 are all fixed on the substrate through a third anchor 33;

The second anchor point 32 and the third anchor point 33 are both close to the first anchor point 31.

In the above embodiment, the arrangement manner of the X-axis detection capacitor set 71 and the Y-axis detection capacitor set 72 is changed, and the second anchor point 32 and the third anchor point 33 for fixing the X-axis detection capacitor set 71 and the Y-axis detection capacitor set 72 are also placed near the first anchor point 31 of the moving structure, so that all the X-axis detection capacitor set 71, the Y-axis detection capacitor set 72 and the first anchor point 31 are located in the structural center of the acceleration sensor, further improving the interference capability of stress resistance and other factors of the acceleration sensor, and helping to ensure the detection accuracy of the acceleration sensor.

Note that, the detection mode of the in-plane X-axis direction means that the acceleration sensor is subjected to the acceleration in the in-plane X-axis direction, see fig. 2, 8, and 14; the detection mode of the in-plane Y-axis direction means that the acceleration sensor is subjected to the acceleration of the in-plane Y-axis direction, see fig. 3, 9 and 15; the detection mode of the out-of-plane Z-axis direction means that the acceleration sensor is subjected to the acceleration of the out-of-plane Z-axis direction, see fig. 4, 10 and 16; parasitic modes in the out-of-plane Z-axis direction refer to that the acceleration sensor is subjected to both the acceleration in the out-of-plane Z-axis direction and the angular acceleration in the Y-axis direction, see fig. 5, 11 and 17.

It is to be understood that the above embodiments are merely illustrative of the application of the principles of the present invention, but not in limitation thereof. Various modifications and improvements may be made by those skilled in the art without departing from the spirit and substance of the invention, and are also considered to be within the scope of the invention.

Claims (12)

1. An acceleration sensor, characterized by comprising:

the device comprises a substrate and a first anchor point, wherein the first anchor point is fixed in the middle of the substrate;

An inner mass unit surrounding and elastically connected to the outside of the first anchor point, and an outer mass unit surrounding and elastically connected to the outside of the inner mass unit;

the device comprises a first seesaw unit and a second seesaw unit, wherein the first seesaw unit and the second seesaw unit are oppositely arranged, and the first seesaw unit and the second seesaw unit are enclosed to form an annular structure; the annular structure surrounds the outer side of the outer side mass unit and is elastically connected with the outer side mass unit;

The first acceleration detection unit and the second acceleration detection unit are arranged on the annular structure, and are used for detecting acceleration along the out-of-plane Z-axis direction; the second acceleration detection unit is arranged on the outer side mass unit and is used for detecting acceleration along the in-plane X-axis direction and the in-plane Y-axis direction;

the out-of-plane Z-axis direction, the in-plane X-axis direction and the in-plane Y-axis direction are perpendicular to each other.

2. The acceleration sensor of claim 1, further comprising a first elastic member and a second elastic member; the extending direction of the first elastic piece is perpendicular to the extending direction of the second elastic piece;

The inner mass unit is elastically connected with the first anchor point through the first elastic piece; the outer side mass unit is elastically connected with the inner side mass unit through the second elastic piece.

3. The acceleration sensor of claim 2, characterized in, that the first elastic member is an X-axis single degree of freedom spring and the second elastic member is a Y-axis single degree of freedom spring;

Or the first elastic piece is a Y-axis single-degree-of-freedom spring, and the second elastic piece is an X-axis single-degree-of-freedom spring.

4. An acceleration sensor according to claim 3, characterized in, that the X-axis single degree of freedom spring is serpentine and/or U-shaped;

the Y-axis single-degree-of-freedom spring is serpentine and/or U-shaped.

5. The acceleration sensor of claim 3, wherein the second acceleration detection unit comprises an X-axis detection capacitor set and a Y-axis detection capacitor set provided on the outer mass unit;

The X-axis detection capacitor groups are symmetrically arranged along an in-plane X-axis, and the X-axis detection capacitor groups are symmetrically arranged along an in-plane Y-axis; the X-axis detection capacitor group is used for detecting acceleration along the X-axis direction in the plane;

The Y-axis detection capacitor groups are symmetrically arranged along an in-plane Y-axis, and the Y-axis detection capacitor groups are symmetrically arranged along an in-plane X-axis; the Y-axis detection capacitor group is used for detecting acceleration along the Y-axis direction in the plane.

6. The acceleration sensor of claim 5, wherein the X-axis sensing capacitor set includes a movable capacitor plate disposed on a sidewall of the outer mass unit, and a first fixed capacitor plate and a second fixed capacitor plate fixed on the substrate; the first fixed capacitor plates and the second fixed capacitor plates are arranged in parallel and at intervals, and are distributed along the Y-axis direction in the plane;

the first fixed capacitor plate and the second fixed capacitor plate are respectively arranged in a differential mode with the movable capacitor plate on the side wall of the outer side quality unit.

7. The acceleration sensor of claim 5, wherein the X-axis sensing capacitor bank comprises a first movable comb capacitor plate disposed on the outer mass unit and a first fixed comb capacitor plate fixed to the base;

the first movable comb-tooth type capacitor electrode plates distributed along the X-axis direction in the plane and the first fixed comb-tooth type capacitor electrode plates are matched to form a first comb-tooth type capacitor.

8. The acceleration sensor of claim 6, wherein the Y-axis sensing capacitor set includes a movable electrode disposed on a sidewall of the outer mass unit, a third fixed capacitor plate fixed to the substrate, and a fourth fixed capacitor plate; the third fixed capacitor plate and the fourth fixed capacitor plate are parallel and are arranged at intervals;

the third fixed capacitor plate and the fourth fixed capacitor plate are respectively arranged in a differential mode with the movable electrode on the side wall of the outer side quality unit.

9. The acceleration sensor of claim 7, wherein the Y-axis sensing capacitor bank comprises a second movable comb capacitor plate disposed on the outer mass unit and a second fixed comb capacitor plate fixed to the base;

The second movable comb-tooth type capacitor electrode plates distributed along the Y-axis direction in the plane are matched with the second fixed comb-tooth type capacitor electrode plates to form a second comb-tooth type capacitor.

10. The acceleration sensor of claim 9, wherein the first fixed comb-tooth capacitive plate is fixed to the substrate by a second anchor; the second fixed comb-tooth type capacitor polar plate is fixed on the substrate through a third anchor point;

The second anchor point and the third anchor point are both near the first anchor point.

11. The acceleration sensor of claim 1, characterized in, that the first teeter-totter unit is elastically connected to one end of the outer mass unit, and the second teeter-totter unit is elastically connected to the other end of the outer mass unit; the first seesaw units and the second seesaw units are symmetrically distributed along the symmetry axis of the acceleration sensor respectively; the first teeterboard units respectively form two first teeterboard structures on two sides of the symmetry axis, and the two first teeterboard structures rotate along the first rotation axis; the second seesaw units respectively form two second seesaw structures on two sides of the symmetrical shaft, and the two second seesaw structures rotate along a second rotating shaft; the first rotating shaft and the second rotating shaft are distributed along the Y-axis direction in the plane, and the symmetrical shafts are distributed along the X-axis direction in the plane.

12. The acceleration sensor of claim 1, further comprising a coupling beam;

Part of the second seesaw units are sleeved on the outer sides of part of the first seesaw units to form a nested structure, the coupling beams are located in the nested structure, one ends of the coupling beams are connected with the first seesaw units, and the other ends of the coupling beams are connected with the second seesaw units.