Inertial measurement module and three-axis accelerometer

Abstract

The invention discloses an inertial measurement module and a three-axis accelerometer, which include a mass block suspended above a substrate through an elastic beam; the elastic beam includes two first elastic beams for connecting the mass block, and two second elastic beams An elastic beam cross-connected with a second elastic beam used to connect the substrate, the two first elastic beams are symmetrically distributed along the center line of the X-axis direction of the mass block, and the second elastic beam deviates from the center line of the Y-axis direction of the mass block; the mass block A first movable electrode and a second movable electrode are also provided in the Y-axis and X-axis directions; in the inertial measurement module of the present invention, the movement of a certain axis in the plane will not be affected by the eccentricity of the structure, and two The mass block is connected to the first elastic beam symmetrical along the X-axis direction of the mass block, which can ensure that the mass block will not deflect along the first elastic beam, and only linear motion will occur between the mass block and the first elastic beam, thereby The accuracy of detection is improved; and the coupling between axes will not be aggravated.

Description

technical field [0001] The invention belongs to the field of micro-electro-mechanical (MEMS), more precisely, relates to a micro-electro-mechanical inertial measurement module, and the invention also relates to a three-axis accelerometer. Background technique [0002] MEMS accelerometer is an inertial device based on MEMS technology, which is used to measure the linear motion acceleration of object motion. It has the characteristics of small size, high reliability, low cost, suitable for mass production, etc., so it has broad market prospects, and its application fields include consumer electronics, aerospace, automobiles, medical equipment and weapons, etc. [0003] At present, there are usually two implementation methods for three-axis accelerometers. One is a patchwork method, which combines three single-axis structures or a dual-axis and a single-axis structure to realize the measurement of three axial accelerations. The second is to use a single structure to realize th...

AI Technical Summary

Problems solved by technology

In the single-structure implementation scheme, the z-axis acceleration is generally measured through the eccentric structure. In this scheme, in addition to the z-axis detection motion, the eccentric feature of the structure is used, and the detection motion of a certain axis (such as the x-axis or y-axis) in the plane is also It will be affected by the eccentric characteristics of the structure, so its motion is actually a swing rather than a linear motion. On the one hand, this motion will intensify the inter-axis coupling, and on the other hand, it will reduce the capacitance change, thus greatly reducing the detection accuracy.

On the other hand, when detecting the y-axis acceleration, due to the characteristics of its structure, it is also possible to make its actual motion be a swing instead of a linear motion, which further reduces the detection accuracy

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