MEMS accelerometer
By designing a mass frame in the MEMS accelerometer, detecting the combined structure of comb pairs, damped comb pairs and spring beams in the MEMS accelerometer, the problems of vulnerability and motion mode instability are solved, and higher sensitivity, linearity and dynamic performance are achieved.
Patent Information
- Application Number
- CN202421611676.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-07-09
- Publication Date
- 2025-06-06
- Estimated Expiration
- 2034-07-09
AI Technical Summary
Existing MEMS accelerometers are prone to damage and the motion mode is not easy to ensure.
A MEMS accelerometer is designed, which includes a mass frame, at least two detection comb pairs, at least one damping comb pair and a plurality of spring beams. The detection comb pair and the damping comb pair are connected through a spring beam, and the damping comb teeth are combined with the damping hole to improve dynamic performance.
This design not only ensures the motion mode of the accelerometer, but also makes the device less prone to damage, improves the sensitivity and linearity of the accelerometer, and enhances dynamic performance.
Smart Images
Figure CN222952377U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of accelerometers, in particular to a MEMS accelerometer. Background Art
[0002] MEMS accelerometers are an important part of inertial measurement systems. They measure acceleration signals based on Newton's second law. Capacitive accelerometers have structures such as comb-tooth capacitors and flat-plate capacitors. Comb-tooth capacitor accelerometers are further divided into variable comb-tooth spacing and variable positive area accelerometers, which have the advantages of strong overload resistance and good stability. Most of the common single-axis MEMS capacitive accelerometers are variable-pitch flat comb-tooth structures, that is, the comb teeth are arranged in parallel around the mass block for capacitance detection. However, this type of comb-tooth capacitor accelerometer is easily damaged and the motion mode is not easy to guarantee.
[0003] Therefore, there is an urgent need to develop a MEMS accelerometer that can both ensure the motion mode of the accelerometer and make the device less susceptible to damage. Utility Model Content
[0004] The utility model aims to provide a MEMS accelerometer to solve the problem that the existing MEMS accelerometer is easy to be damaged and the motion mode is difficult to guarantee.
[0005] To solve the above technical problems, the utility model provides a MEMS accelerometer, including a mass frame, in which at least two detection comb tooth pairs, at least one damping comb tooth pair, and a plurality of spring beams are arranged, the at least two detection comb tooth pairs are symmetrically arranged on both sides of the damping comb tooth pair, and the detection comb tooth pair and the damping comb tooth pair are connected by the spring beam.
[0006] Optionally, the detection comb teeth pair includes detection movable comb teeth and first fixed comb teeth, and the detection movable comb teeth and the first fixed comb teeth are arranged alternately at intervals; the damping comb teeth pair includes damping movable comb teeth and second fixed comb teeth, and the damping movable comb teeth and the second fixed comb teeth are arranged alternately at intervals.
[0007] Optionally, it also includes multiple first anchors, multiple second anchors and multiple third anchors, one end of the spring beam is connected to the first anchor, the other end of the spring beam is connected to the mass frame, the first fixed comb teeth are connected to the second anchor, the detection movable comb teeth are connected to the mass frame, the second fixed comb teeth are connected to the third anchor, and the damping movable comb teeth are connected to the mass frame.
[0008] Optionally, the plurality of spring beams are arranged in multiple rows along the X direction, the multiple rows of spring beams are symmetrically arranged about a center line of the mass frame extending along the X direction, and the spring beams are decoupled along the Y direction.
[0009] Optionally, the plurality of detection movable comb teeth are arranged in a plurality of rows along the X direction, and the plurality of rows of detection movable comb teeth are symmetrically arranged about a center line of the mass frame extending along the X direction.
[0010] Optionally, the plurality of detection movable comb teeth are arranged in two rows.
[0011] Optionally, the comb teeth of each detection movable comb tooth are located between two adjacent comb teeth of the first fixed comb teeth, and the interval between two adjacent comb teeth of the first fixed comb teeth and the comb teeth of the detection movable comb teeth arranged therebetween is equal.
[0012] Optionally, a plurality of the damping movable comb teeth are arranged in at least one row along the X direction, and the damping movable comb teeth are symmetrically arranged about a center line of the mass frame extending along the X direction.
[0013] Optionally, it also includes a damping hole arranged on the mass frame.
[0014] Optionally, the damping hole is arranged between the detection comb teeth pair and the spring beam and / or between the damping comb teeth pair and the spring beam.
[0015] The MEMS accelerometer provided by the utility model has the following beneficial effects:
[0016] First, the layout of the spring beam can ensure the motion mode of the accelerometer while making the spring beam less prone to damage.
[0017] Secondly, when the accelerometer is subjected to external acceleration, the mass frame produces relative movement in different directions. At this time, the facing area of the plates between the moving comb teeth and the fixed comb teeth changes, thereby causing the output capacitance to change. By detecting the change in capacitance, the corresponding acceleration can be measured. By detecting the difference of the moving comb teeth, the sensitivity and linearity of the accelerometer can be improved.
[0018] Thirdly, the accelerometer structure adopts a combination of damping comb teeth and damping holes, which can make the accelerometer have higher dynamic performance and is conducive to stress release during the device processing. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 It is a structural schematic diagram of a MEMS accelerometer in an embodiment of the utility model;
[0020] Figure 2 yes Figure 1 A partial enlarged schematic diagram of
[0021] Figure 3 It is the motion mode of the MEMS accelerometer in the embodiment of the utility model.
[0022] 100-mass frame; 110-damping hole; 200-first anchor; 300-spring beam; 400-first fixed comb teeth; 500-second anchor; 600-detection movable comb teeth; 700-damping movable comb teeth; 800-third anchor; 900-second fixed comb teeth. DETAILED DESCRIPTION
[0023] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.
[0024] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the present invention to be protected, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0025] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.
[0026] In the description of the present utility model, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate the orientation or position relationship based on the orientation or position relationship shown in the accompanying drawings, or the orientation or position relationship in which the utility model product is usually placed when in use, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.
[0027] In addition, the terms "horizontal", "vertical" and the like do not mean that the components are required to be absolutely horizontal or suspended, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.
[0028] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0029] refer to Figure 1 , Figure 2 and Figure 3 , Figure 1 is a schematic diagram of the structure of a MEMS accelerometer in an embodiment of the utility model, Figure 2 yes Figure 1 A partial enlarged schematic diagram of Figure 3 It is the motion mode of the MEMS accelerometer in the embodiment of the utility model. The embodiment provides a MEMS accelerometer, including a mass frame 100. At least two detection comb tooth pairs, at least one damping comb tooth pair, and a plurality of spring beams are arranged in the mass frame 100. At least two of the detection comb tooth pairs are symmetrically arranged on both sides of the damping comb tooth pair, and the detection comb tooth pair and the damping comb tooth pair are connected by the spring beam.
[0030] Specifically, the detection comb teeth pair includes detection movable comb teeth 600 and first fixed comb teeth 400, and the detection movable comb teeth 600 and the first fixed comb teeth 400 are arranged alternately at intervals. The damping comb teeth pair includes damping movable comb teeth 700 and second fixed comb teeth 900, and the damping movable comb teeth 700 and the second fixed comb teeth 900 are arranged alternately at intervals.
[0031] The MEMS accelerometer further includes a plurality of first anchors 200, a plurality of second anchors 500 and a plurality of third anchors 800, one end of the spring beam 300 is connected to the first anchor 200, the other end of the spring beam 300 is connected to the mass frame 100, the first fixed comb teeth 400 are connected to the second anchor 500, the detection movable comb teeth 600 are connected to the mass frame 100, the second fixed comb teeth 900 are connected to the third anchor 800, and the damping movable comb teeth 700 are connected to the mass frame 100.
[0032] The plurality of spring beams 300 are arranged in two rows along the X direction, and the two rows of spring beams 300 divide the mass frame 100 into three parts, namely, a first area, a second area and a third area, along the Y direction.
[0033] Each row of spring beams 300 includes a plurality of spring beams 300 .
[0034] Preferably, each row of spring beams 300 includes three spring beams 300. In this way, the stress on a single spring beam 300 can be reduced, making the spring beam 300 less likely to be damaged.
[0035] Each spring beam 300 includes two symmetrically arranged spring beams.
[0036] The first fixed comb teeth 400 are connected to the second anchor 500, the detection movable comb teeth 600 are connected to the quality frame 100, the detection movable comb teeth 600 and the fixed comb teeth are arranged alternately, and a plurality of the detection movable comb teeth 600 are arranged in multiple rows along the X direction, and the multiple rows of the detection movable comb teeth 600 are symmetrically arranged about the center line of the quality frame 100 extending along the X direction.
[0037] The plurality of detection moving comb teeth 600 are arranged in two rows and are respectively located in the first zone and the third zone. Thus, when the accelerometer is subjected to external acceleration, the mass block produces relative movement along the Y-axis direction. At this time, the facing area of the plates between the detection moving comb teeth 600 and the fixed comb teeth changes, thereby causing the output capacitance to change. By detecting the capacitance change, the corresponding acceleration can be measured. By detecting the difference of the moving comb teeth 600, the sensitivity and linearity of the accelerometer can be improved.
[0038] There are multiple detection movable comb teeth 600 in each row. Preferably, there are three detection movable comb teeth 600.
[0039] The teeth of each detection movable comb tooth 600 are located between two adjacent teeth of the first fixed comb teeth 400 , and the interval between two adjacent teeth of the first fixed comb teeth 400 and the teeth of the detection movable comb tooth 600 disposed therebetween is equal.
[0040] The second fixed comb teeth 900 are connected to the third anchor 800, the damping movable comb teeth 700 are connected to the mass frame 100, the damping movable comb teeth 700 and the second fixed comb teeth 900 are arranged alternately at intervals, a plurality of the damping movable comb teeth 700 are arranged in at least one row along the X direction, and the damping movable comb teeth 700 are symmetrically arranged about the center line of the mass frame 100 extending along the X direction.
[0041] The damping movable comb teeth 700 are arranged in a row and located in the second zone.
[0042] The number of the damping movable comb teeth 700 is multiple, and preferably, the number of the damping movable comb teeth 700 is three.
[0043] The MEMS accelerometer further includes a damping hole 110 disposed on the mass frame to improve the dynamic performance of the MEMS accelerometer.
[0044] The damping hole 110 is disposed between the detection comb teeth pair and the spring beam and / or between the damping comb teeth pair and the spring beam.
[0045] The above description is only a description of the preferred embodiment of the utility model, and is not any limitation on the scope of the utility model. Any changes and modifications made by ordinary technicians in the field of the utility model based on the above disclosure shall fall within the scope of protection of the claims.
Claims
1. A MEMS accelerometer, comprising a mass frame, characterized in that: At least two detection comb tooth pairs, at least one damping comb tooth pair and a plurality of spring beams are arranged in the mass frame, the at least two detection comb tooth pairs are symmetrically arranged on both sides of the damping comb tooth pair, and the detection comb tooth pair and the damping comb tooth pair are connected through the spring beam.
2. The MEMS accelerometer according to claim 1, wherein: The detection comb teeth pair includes detection movable comb teeth and first fixed comb teeth, and the detection movable comb teeth and the first fixed comb teeth are arranged alternately. The damping comb teeth pair includes damping movable comb teeth and second fixed comb teeth, and the damping movable comb teeth and the second fixed comb teeth are arranged alternately.
3. The MEMS accelerometer according to claim 2, wherein: It also includes multiple first anchors, multiple second anchors and multiple third anchors, one end of the spring beam is connected to the first anchor, the other end of the spring beam is connected to the mass frame, the first fixed comb teeth are connected to the second anchor, the detection movable comb teeth are connected to the mass frame, the second fixed comb teeth are connected to the third anchor, and the damping movable comb teeth are connected to the mass frame.
4. The MEMS accelerometer according to claim 2, wherein: The plurality of spring beams are arranged in a plurality of rows along the X direction, the plurality of rows of spring beams are symmetrically arranged about a center line of the mass frame extending along the X direction, and the spring beams are decoupled along the Y direction.
5. The MEMS accelerometer according to claim 2, wherein: The plurality of movable detection comb teeth are arranged in a plurality of rows along the X direction, and the plurality of rows of movable detection comb teeth are symmetrically arranged about a center line of the mass frame extending along the X direction.
6. The MEMS accelerometer according to claim 5, wherein: The plurality of detection movable comb teeth are arranged in two rows.
7. The MEMS accelerometer according to claim 5, wherein: The comb teeth of each detecting movable comb tooth are located between two adjacent comb teeth of the first fixed comb teeth, and the interval between the two adjacent comb teeth of the first fixed comb teeth and the comb teeth of the detecting movable comb teeth arranged therebetween is equal.
8. The MEMS accelerometer according to claim 2, wherein: The plurality of damping movable comb teeth are arranged in at least one row along the X direction, and the damping movable comb teeth are symmetrically arranged about a center line of the mass frame extending along the X direction.
9. The MEMS accelerometer according to claim 1, wherein: Also included is a damping hole disposed in the mass frame. 10 . The MEMS accelerometer according to claim 9 , wherein the damping hole is arranged between the detection comb teeth pair and the spring beam and / or between the damping comb teeth pair and the spring beam.