On Fabrication of Two-dimensional Micro Vibratory Gyroscopes by Quasi-LIGA-like Process

• Main Authors: Sang-Fa Hou, 侯勝發
• Other Authors: Ming-Shaung Ju
• Format: Others
• Language: zh-TW
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/42510877435351565670

碩士 === 國立成功大學 === 機械工程學系 === 88 === The gyro is getting more important applications in many fields. A traditional gyro has some drawbacks, for example, they are bulky in volume and wear of bearings is not avoidable. However, the vibratory micro gyro can sense changes of angular velocity based on conservation of momentum and due to its simple and fixed structure the gyro doesn’t has the problem of wear. The size of a vibratory gyro is small so it has higher bandwidth and better linearity than those of a traditional gyro. This research employs finite element method software (ANSYS) to design a two-dimensional vibratory micro gyro. Electro-static force will be utilized to excite resonant vibration of the structure and capacitance change between cantilever plate and electrode on substrate will be used to transduce the angular velocities. The micro gyro is fabricated by Quasi-LIGA-like process and integrated circuit thin film technologies. In particular, this research is focused on the development of excimer-laser-ablated polyimide mold and techniques to methods improve the quality of micromachined molds. In summary, the design and analysis work in this research are finished. The gyro will be driven by electrostatic comb actuators with 5 volt in vacuum and it senses angular velocity by a capacitance circuit. In the operating range of 0-600 deg/sec the sensitivity and linearity of the gyro are and 9.8%, respectively. In excimer laser ablation process, a metal thin film can be used to prevent the micro molds from over machining yielded additional diffraction energy. This method can increase the resolution and aspect ratio of micro molds. In gyro manufacturing, the micro mold is ablated and a un-suspended nickel structure of gyro is electrodeposited. The minimum gap of comb actuator is 4 mm and the maximum aspect ratio is more than 2.