High-sensitivity bulk acoustic wave silicon microgyroscope

Abstract

The invention discloses a high-sensitivity bulk acoustic wave silicon microgyroscope in the technical field of micro electro mechanical systems. The high-sensitivity bulk acoustic wave silicon microgyroscope comprises a disc-shaped harmonic oscillator, a supporting cylinder, a circular arc driving electrode, a detection electrode with a displacement mechanism, a detection electrode fixing boss and a base plate. A gyroscope utilizes four-amplitude wave node frequency matching modes of two surfaces of the disc-shaped harmonic oscillator as a driving mode and a detection mode, and all structures are completely realized by a micro electro mechanical machining process on a (111) silicon wafer. According to the high-sensitivity bulk acoustic wave silicon microgyroscope, a displacement enlargement mechanism based on a lever principle is used for outputting and enlarging infinitesimal displacement at the detection mode, so as to improve the sensitivity of the gyroscope, largely simplify the machining process of the bulk acoustic wave silicon microgyroscope, and reduce the production cost.

Description

technical field [0001] The invention relates to a micro-gyroscope in the field of micro-electromechanical technology, in particular to a high-sensitivity bulk acoustic wave silicon micro-gyroscope. Background technique [0002] Micro gyroscope is an inertial device made by micro-mechanical electronics (MEMS) technology that can be sensitive to the angle or angular velocity of the carrier. It plays a very important role in the fields of attitude control, navigation and positioning. With the wide application of silicon micro gyroscopes in consumer electronics attitude control systems, automotive auxiliary navigation and safety control systems, industrial robot attitude control, weapon inertial guidance and other fields, gyroscopes are moving towards high precision, miniaturization, and low cost. direction development. [0003] The traditional silicon micro-gyroscope with comb-like interdigital structure usually works in the frequency range of 1KHz-90KHz, using a square mass a...

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Problems solved by technology

[0004] Since the gyroscope with a disk-shaped vibrator has high stiffness and high operating frequency, the amplitude of the reference vibration generated in its driving mode is small, so the vibration output of the sensitive mode caused by the angular velocity input is also small. , in order to increase the sensitivity of the gyroscope, the gap between the arc-shaped driving electrode and the detecting electrode and the disc-shaped resonator needs to adopt an ultra-high aspect ratio (about 200:1) process, and it is very difficult to process the high aspect ratio capacitor gap. Moreover, due to the small gap width, it is difficult to control the surface roughness accuracy of the side wall, and it is easy to cause tunneling during the working process.

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