Tri-axial micro-electro-mechanical gyroscope

Abstract

The utility model relates to the field of micro electro mechanical system technology, specifically disclose three -axis micro electro mechanical gyroscope. The gyroscope includes by the lower wafer, mass block and upper wafer that set gradually from below to above, mass block and lower wafer swing joint, mass block and upper wafer swing joint, the bottom of mass block and the upper board surface of lower wafer one of both convex has a plurality of lower limit post along the vertical direction extension, the other recessed has the lower limit slot along the vertical direction extension, and the lower limit slot is same in quantity with lower limit post, and every lower limit post is partially placed in a lower limit slot, the top of mass block and the lower board surface of upper wafer one of both convex has a plurality of upper limit post along the vertical direction extension, the other recessed has the upper limit slot along the vertical direction extension, and the upper limit slot is same in quantity with upper limit post, and every upper limit post is partially placed in a upper limit slot. The gyroscope provides physical limit in space, and the excessive displacement of mass block in space is limited.

Description

Technical Field

[0001] This utility model relates to the field of microelectromechanical systems (MEMS) technology, and in particular to a three-axis MEMS gyroscope. Background Technology

[0002] Microelectromechanical systems (MEMS) technology has become central to the modern sensor field. Among them, triaxial MEMS gyroscopes, capable of simultaneously detecting angular velocities in three directions, are widely used in consumer electronics, the automotive industry, and aerospace. The core working mechanism of this type of gyroscope typically relies on a movable mass suspended by a cantilever beam structure. This mass vibrates under drive, and when subjected to an external angular velocity, it induces a Coriolis force, causing displacement in a specific direction. By detecting this displacement, the angular velocity information can be calculated.

[0003] In existing technologies, cantilever beam structures are key components that support and guide the movement of mass blocks, and their design directly determines the performance and reliability of sensors. However, the field has long faced a fundamental and irreconcilable contradiction: there is an inherent trade-off between the structural stiffness of the cantilever beam and sensor performance.

[0004] Specifically, the dimensional parameters of the cantilever beam, such as its thickness, directly reflect its stiffness. To ensure the reliability of the gyroscope under harsh environments (such as impact and vibration) and to prevent excessive displacement of the mass block from causing plastic deformation or fracture of the cantilever beam, designers typically prefer to use thicker, more robust cantilever beams. While this design improves the mechanical robustness and overload resistance of the device, it also significantly increases the support stiffness, severely limiting the motion sensitivity and displacement amplitude of the mass block in the sensing direction. The direct consequence is a reduced signal-to-noise ratio and decreased detection accuracy of the sensor, resulting in overall performance that fails to meet the requirements of high-end applications.

[0005] Conversely, if a thinner, more flexible cantilever beam is used to pursue high sensitivity and performance, the mass can gain greater degrees of freedom of movement, thus enhancing the sensing signal. However, this design makes the entire structure exceptionally fragile. When subjected to external impacts or severe vibrations, the mass is prone to excessive displacement far exceeding the design limits, leading to stress concentration in the cantilever beam and instantaneous fracture, causing the device to fail completely.

[0006] Therefore, existing three-axis MEMS gyroscopes are caught in a design dilemma: pursuing reliability sacrifices performance, while optimizing performance inevitably carries reliability risks. This contradiction severely restricts the development of high-performance, highly robust MEMS gyroscopes. Utility Model Content

[0007] The purpose of this invention is to provide a three-axis microelectromechanical gyroscope that provides physical limits in space, thereby restricting excessive displacement of the mass block in space.

[0008] To achieve this objective, the present invention adopts the following technical solution:

[0009] A three-axis microelectromechanical gyroscope includes a lower wafer, a mass block, and an upper wafer arranged sequentially from bottom to top. The mass block is movably connected to both the lower and upper wafers. One of the bottom end of the mass block and the upper surface of the lower wafer has a plurality of vertically extending lower limit posts protruding from it, and the other has a vertically extending lower limit groove recessed therein. The number of lower limit grooves is the same as the number of lower limit posts, and each lower limit post is partially placed within one of the lower limit grooves. Similarly, one of the top end of the mass block and the lower surface of the upper wafer has a plurality of vertically extending upper limit posts protruding from it, and the other has a vertically extending upper limit groove recessed therein. The number of upper limit grooves is the same as the number of upper limit posts, and each upper limit post is partially placed within one of the upper limit grooves.

[0010] As an optional technical solution for a three-axis microelectromechanical gyroscope, the number of lower limit posts and upper limit posts is the same, and the projection center of each lower limit post in the horizontal plane overlaps with the projection center of one upper limit post in the horizontal plane, and the projection center of each lower limit slot in the horizontal plane overlaps with the projection center of one upper limit slot in the horizontal plane.

[0011] As an optional technical solution for a three-axis microelectromechanical gyroscope, the lower limiting post is located on the upper surface of the lower wafer, and the lower limiting groove is located at the bottom of the mass block; the upper limiting post is located on the lower surface of the upper wafer, and the upper limiting groove is located at the top of the mass block.

[0012] As an optional technical solution for a three-axis microelectromechanical gyroscope, each corner of the bottom end of the mass block is provided with a lower limit groove, and each corner of the top end of the mass block is provided with an upper limit groove.

[0013] As an optional technical solution for a three-axis microelectromechanical gyroscope, the projection of the mass block in the horizontal plane is rectangular; there are four lower limit posts and four upper limit posts.

[0014] As an optional technical solution for a three-axis microelectromechanical gyroscope, the lower limit post is integrally formed on the lower wafer.

[0015] As an optional technical solution for a three-axis microelectromechanical gyroscope, the upper limit post is integrally formed on the upper wafer.

[0016] As an optional technical solution for a three-axis microelectromechanical gyroscope, the projection of each lower limit post in the horizontal plane coincides with the projection of one upper limit post in the horizontal plane, and the projection of each lower limit slot in the horizontal plane coincides with the projection of one upper limit slot in the horizontal plane.

[0017] As an optional technical solution for a three-axis microelectromechanical gyroscope, the projection of the lower limiting groove in the horizontal plane is rectangular, and the projection of the lower limiting post in the horizontal plane is rectangular.

[0018] As an optional technical solution for a three-axis microelectromechanical gyroscope, the projection of the upper limit slot in the horizontal plane is rectangular, and the projection of the upper limit post in the horizontal plane is rectangular.

[0019] The beneficial effects of this utility model are:

[0020] This triaxial MEMS gyroscope provides physical restraint in space by using a lower restraint post and lower restraint slot between the lower wafer and the mass block, and an upper restraint post and upper restraint slot between the upper wafer and the mass block, thus limiting excessive displacement of the mass block in space. This effectively prevents the cantilever beam from breaking due to excessive displacement of the mass block under impact or vibration environments. This allows for the use of thinner cantilever beams while maintaining good sensing performance, significantly improving the shock resistance and reliability of the triaxial MEMS gyroscope. The restraint structure allows the mass block to move within a safe range, avoiding the trade-off between reliability and performance in traditional cantilever beam designs. Furthermore, the restraint structure enables multi-directional motion control and enhances shock resistance, forming a complete three-dimensional restraint structure. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the three-axis microelectromechanical gyroscope provided in this embodiment of the utility model;

[0022] Figure 2 yes Figure 1 Cross-sectional view of plane AA;

[0023] Figure 3 This is a partial cross-sectional view of the triaxial microelectromechanical gyroscope provided in this embodiment of the present invention.

[0024] In the picture:

[0025] 100, Lower wafer; 101, Lower limit post; 200, Mass block; 201, Lower limit slot; 202, Upper limit slot; 300, Upper wafer; 301, Upper limit post. Detailed Implementation

[0026] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0027] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The terms "first position" and "second position" refer to two different positions. Moreover, "above," "on top of," and "over" the first feature in relation to the second feature includes the first feature directly above and diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "under," and "below" the first feature in relation to the second feature includes the first feature directly below and diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0028] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0029] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0030] like Figures 1 to 3As shown, this utility model provides a three-axis microelectromechanical gyroscope, including a lower wafer 100, a mass block 200, and an upper wafer 300 arranged sequentially from bottom to top. The mass block 200 is movably connected to the lower wafer 100 and the upper wafer 300. One of the bottom end of the mass block 200 and the upper surface of the lower wafer 100 has a plurality of vertically extending lower limit posts 101 protruding from it, and the other has a vertically extending lower limit groove 201 recessed therein. The number of slots 201 and lower limit posts 101 is the same, and each lower limit post 101 is partially placed in a lower limit slot 201; one of the top of the mass block 200 and the lower surface of the upper wafer 300 is provided with a number of upper limit posts 301 extending vertically, and the other is provided with upper limit slots 202 extending vertically. The number of upper limit slots 202 and upper limit posts 301 is the same, and each upper limit post 301 is partially placed in an upper limit slot 202.

[0031] This triaxial MEMS gyroscope provides physical restraint in space by using a lower limiting post 101 and a lower limiting slot 201 between the lower wafer 100 and the mass block 200, and an upper limiting post 301 and an upper limiting slot 202 between the upper wafer 300 and the mass block 200. This restricts excessive displacement of the mass block 200 in space. This effectively prevents the cantilever beam from breaking due to excessive displacement of the mass block 200 under impact or vibration conditions. Thus, while allowing the use of a thinner cantilever beam to maintain good sensing performance, it significantly improves the shock resistance and reliability of the triaxial MEMS gyroscope. The restraint structure allows the mass block 200 to move within a safe range, avoiding the trade-off between reliability and performance in traditional cantilever beam designs. Furthermore, the restraint structure enables multi-directional motion control and enhances shock resistance, forming a complete three-dimensional restraint structure.

[0032] In this embodiment, the number of lower limit posts 101 and upper limit posts 301 is the same, and the projection center of each lower limit post 101 in the horizontal plane overlaps with the projection center of an upper limit post 301 in the horizontal plane, and the projection center of each lower limit groove 201 in the horizontal plane overlaps with the projection center of an upper limit groove 202 in the horizontal plane.

[0033] By ensuring that the number of lower limit posts 101 and upper limit posts 301 are the same and their projection centers overlap, and that the projection centers of lower limit slots 201 and upper limit slots 202 overlap, the symmetry and balance of the limiting structure are ensured. This aligned design provides a uniform limiting force, ensuring a uniform distribution of the limiting effect, preventing the mass block 200 from tilting or deflecting during movement, further enhancing the stability and consistency of the limiting structure, improving the stability and reliability of the three-axis MEMS gyroscope, and reducing stress concentration caused by asymmetrical limiting. The symmetrical layout also reduces the swaying of the mass block 200 under complex movements, enhancing the accuracy of the three-axis MEMS gyroscope, while making the movement of the mass block 200 more controllable, reducing false alarms or performance fluctuations.

[0034] Furthermore, the lower limit post 101 is disposed on the upper plate surface of the lower wafer 100, and the lower limit groove 201 is disposed at the bottom end of the mass block 200; the upper limit post 301 is disposed on the lower plate surface of the upper wafer 300, and the upper limit groove 202 is disposed at the top end of the mass block 200.

[0035] The aforementioned layout simplifies the manufacturing process and assembly. This arrangement makes the limiting structure more stable, reduces stress concentration on the mass block 200, and improves the overall structural strength and durability. Simultaneously, since the upper wafer 300 and lower wafer 100 serve as the basic structure, the lower limiting post 101 and upper limiting post 301 are easier to mold or process with precision, while the slots on the mass block 200 are easier to align, improving production efficiency and product consistency. This reduces manufacturing costs and complexity, and enhances the reliability of the limiting structure.

[0036] Furthermore, each corner of the bottom of the mass block 200 is provided with a lower limit groove 201, and each corner of the top of the mass block 200 is provided with an upper limit groove 202.

[0037] Lower limit grooves 201 and upper limit grooves 202 are provided at the corners of the mass block 200, achieving the most effective support and limitation for the mass block 200. This ensures that the mass block 200 can be effectively limited within a safe displacement range when subjected to impact from any direction, effectively preventing excessive displacement or tilting of the mass block 200 in any direction. This significantly improves the shock resistance and reliability of the triaxial MEMS gyroscope, making it particularly suitable for motion scenarios in space. It can evenly distribute stress, reduce local loads on cantilever beams, prevent failures caused by corner stress concentration, and extend the service life of the triaxial MEMS gyroscope.

[0038] Furthermore, the projection of the mass block 200 in the horizontal plane is a rectangle; there are four lower limit posts 101 and four upper limit posts 301.

[0039] The rectangular mass block 200, in conjunction with four symmetrically distributed lower limit posts 101 and four upper limit posts 301, provides symmetrical and stable limiting support, ensuring uniform constraint on movement within the horizontal plane and reducing reliance on the strength of the cantilever beam. This design optimizes the three-dimensional limiting effect, ensuring uniform distribution of limiting force and preventing rotation or displacement of the mass block 200 during movement, thereby improving the accuracy and reliability of the three-axis microelectromechanical gyroscope. Simultaneously, the combination of the rectangular structure with the four lower limit posts 101 and four upper limit posts 301 optimizes space utilization, making the limiting effect more comprehensive, and is easier to manufacture and arrange, improving process feasibility.

[0040] In this embodiment, the lower limit post 101 is integrally formed on the lower wafer 100; the upper limit post 301 is integrally formed on the upper wafer 300.

[0041] By integrally molding the lower limit post 101 onto the lower wafer 100 and the upper limit post 301 onto the upper wafer 300, the overall structural integrity and mechanical strength between the lower wafer 100 and the mass block 200, as well as between the upper wafer 300 and the mass block 200, are enhanced. This integral molding reduces the number of parts and assembly steps, lowers the risk of failure of the upper limit post 301 and the lower limit post 101 due to weak connection points, reduces potential failure points, and ensures long-term stability and reliability. The integral molding process also makes the structure more compact, which is beneficial for the miniaturization and integration of three-axis microelectromechanical gyroscopes and simplifies process development.

[0042] For example, the projection of each lower limit post 101 in the horizontal plane coincides with the projection of an upper limit post 301 in the horizontal plane, and the projection of each lower limit groove 201 in the horizontal plane coincides with the projection of an upper limit groove 202 in the horizontal plane.

[0043] By aligning the lower limiting post 101 and the upper limiting post 301 in their horizontal projections, and the lower limiting groove 201 and the upper limiting groove 202 in their horizontal projections, precise alignment of the limiting structure in the vertical direction is achieved. This ensures consistent restriction of the vertical movement of the mass block 200, providing more accurate limiting, preventing stress unevenness caused by asymmetric displacement, and further optimizing the limiting effect. This prevents the mass block 200 from shifting or rotating during movement, improving the accuracy and reliability of the limiting, thereby optimizing the dynamic response capability of the three-axis MEMS gyroscope and enhancing its reliability.

[0044] In this embodiment, the projection of the lower limiting groove 201 in the horizontal plane is a rectangle, and the projection of the lower limiting post 101 in the horizontal plane is a rectangle; the projection of the upper limiting groove 202 in the horizontal plane is a rectangle, and the projection of the upper limiting post 301 in the horizontal plane is a rectangle.

[0045] The lower limiting groove 201 and lower limiting post 101, as well as the upper limiting groove 202 and upper limiting post 301 of the rectangular projection, provide clearer limiting boundaries, effectively restricting the linear displacement and rotation of the mass block 200 in the horizontal plane. The rectangular shape is easy to process and align, improving manufacturing accuracy. Simultaneously, it effectively limits the rotation or lateral displacement of the mass block 200, reducing lateral swaying during movement and enhancing the accuracy and reliability of the limiting. The rectangular structure also facilitates processing and inspection, improving manufacturing efficiency.

[0046] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A three-axis microelectromechanical gyroscope, characterized in that, The assembly includes a lower wafer (100), a mass block (200), and an upper wafer (300) arranged sequentially from bottom to top. The mass block (200) is movably connected to the lower wafer (100) and the upper wafer (300). One of the bottom end of the mass block (200) and the upper surface of the lower wafer (100) is provided with a plurality of vertically extending lower limiting posts (101), while the other is provided with a vertically extending lower limiting groove (201). The lower limiting groove (201) and the upper surface of the lower wafer (100) are connected in series. The number of posts (101) is the same, and each of the lower limit posts (101) is partially placed in a lower limit groove (201); the top of the mass block (200) and the lower plate surface of the upper wafer (300) are provided with a plurality of upper limit posts (301) extending in the vertical direction, and the other is provided with an upper limit groove (202) extending in the vertical direction. The number of upper limit grooves (202) is the same as the number of upper limit posts (301), and each of the upper limit posts (301) is partially placed in a upper limit groove (202).

2. The triaxial microelectromechanical gyroscope according to claim 1, characterized in that, The number of lower limit posts (101) and upper limit posts (301) is the same, and the projection center of each lower limit post (101) in the horizontal plane overlaps with the projection center of one upper limit post (301) in the horizontal plane. The projection center of each lower limit groove (201) in the horizontal plane overlaps with the projection center of one upper limit groove (202) in the horizontal plane.

3. The triaxial microelectromechanical gyroscope according to claim 2, characterized in that, The lower limiting post (101) is located on the upper plate surface of the lower wafer (100), and the lower limiting groove (201) is located at the bottom end of the mass block (200); the upper limiting post (301) is located on the lower plate surface of the upper wafer (300), and the upper limiting groove (202) is located at the top end of the mass block (200).

4. The triaxial microelectromechanical gyroscope according to claim 3, characterized in that, Each corner of the bottom end of the mass block (200) is provided with a lower limiting groove (201), and each corner of the top end of the mass block (200) is provided with an upper limiting groove (202).

5. The triaxial microelectromechanical gyroscope according to claim 4, characterized in that, The projection of the mass block (200) in the horizontal plane is rectangular; there are four lower limit posts (101) and four upper limit posts (301).

6. The triaxial microelectromechanical gyroscope according to claim 3, characterized in that, The lower limit post (101) is integrally formed on the lower wafer (100).

7. The triaxial microelectromechanical gyroscope according to claim 3, characterized in that, The upper limit post (301) is integrally formed on the upper wafer (300).

8. The triaxial microelectromechanical gyroscope according to claim 2, characterized in that, The projection of each lower limit post (101) in the horizontal plane coincides with the projection of an upper limit post (301) in the horizontal plane, and the projection of each lower limit groove (201) in the horizontal plane coincides with the projection of an upper limit groove (202) in the horizontal plane.

9. The triaxial microelectromechanical gyroscope according to any one of claims 1-8, characterized in that, The projection of the lower limiting groove (201) in the horizontal plane is a rectangle, and the projection of the lower limiting post (101) in the horizontal plane is a rectangle.

10. The triaxial microelectromechanical gyroscope according to any one of claims 1-8, characterized in that, The projection of the upper limit slot (202) in the horizontal plane is a rectangle, and the projection of the upper limit post (301) in the horizontal plane is a rectangle.

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