论文标题:基于滑膜阻尼效应的音叉式微机械陀螺研究
Research of Tuning Fork Type Micromachined Gyroscope Based on Slide-Film Damping
论文作者 陈永
论文导师 王跃林,论文学位 博士,论文专业 微电子与固体电子学
论文单位 中国科学院研究生院（上海微系统与信息技术研究所）,点击次数 93,论文页数 125页File Size13348k
2004-06-01论文网 http://www.lw23.com/lunwen_37486957/ 微机电系统,微机械陀螺,滑膜阻尼,机械解耦,等效电路模型
Micro-Electro-Mechanical System, Micromachined Gyroscope, Slide-film Damping, Mechanical Decoupling, Equivalent Circuit Model
与传统陀螺相比，微机械陀螺具有体积小、重量轻、成本低等特点，因而具有广泛的应用前景。在微机械陀螺的研究中，陀螺灵敏度和分辨率的提高始终是人们追求的主要目标。本论文工作是针对一种具有实用化目标的新型结构的微机械陀螺进行研究，包括器件结构的原理设计、工艺制作、封装和性能测试等。 在对振动式微机械陀螺的基本原理和动力学方程进行分析的基础上，讨论了工作频率、Q值和驱动力矩与陀螺灵敏度及其工作带宽的关系。讨论了微机械陀螺中的空气阻尼、正交误差、寄生Coriolis力以及轴向加速度干扰等问题。 在总结理论分析结果和前人工作经验的基础上，提出一种新颖的微机械陀螺设计：采用电磁驱动方式，具有较大的驱动力矩，幅值稳定；驱动模态和检测模态的空气阻尼均主要为滑膜阻尼，在大气压下实现了较高的Q值；采用解耦结构设计减小了结构中的机械耦合；音叉式结构设计使陀螺能够抑制轴向加速度的干扰。 设计了陀螺的动力学结构和电学结构，分析了噪声特性和加速度响应特性。陀螺驱动模态和检测模态的固有频率和Q值的设计值分别为2800Hz和1613，3000Hz和1613。陀螺热噪声的设计值为0.123°／h／Hz~(1/2)。 采用单晶硅体微机械加工工艺和硅玻璃静电键合技术实现了音叉式微机械陀螺的制作，分析并解决了陀螺制作工艺过程中的深反立离子刻蚀根部效应问题和图形边缘变形问题。 建立了音叉式微机械陀螺的动力学等效电路模型，对音叉式微机械陀螺的工作特性进行了模拟。对设计出的陀螺接口电路的各级输出参数进行了测试和验证，实现了接口电路的功能。 在大气下实现了微机械陀螺的封装，对器件性能进行了测试。陀螺在大气压下驱动模态谐振频率和Q值分别为2906Hz和1004，检测模态中两个检测质量块振动系统谐振频率和Q值分别为2996Hz和522、3033Hz和421。陀螺的标度因子灵敏度为9.8mV／°／s，非线性为0.43％，噪声等效角速度和零点漂移分别为67°／h／Hz~(1/2)和144°／h。 分析和测试结果表明，本论文设计制作的音叉式微机械陀螺在大气压下实现了较基于滑膜阻尼效应的音又式微机械陀螺研究高的Q值和灵敏度，较低的机械祸合和热噪声，同时能够有效抑制轴向加速度的干扰。性能基本能够满足初步应用要求。
Micromachined gyroscopes have a variety of applications in many fields due to their small size, light weight and low cost. Many effort 5 have been spent in improving the sensitivity in past years, In this dissertation, a novel micromachined vibratory gyroscope, based on slide-film damping principle, is investigated, including the operating principle, design and fabrication, packaging and measurement of the device.By means of analyzing the fundamentals and dynamic characteristics of micromachined vibratory gyroscopes, the influence of the operating frequencies, Q-values and driving force on the sensitivity and bandwidth of the device has been discussed. The air damping, quadrature error, parasite Coriolis force and interference from axial accelerations are also discussed.On the basis of theoretic analysis and previous works, we proposed a novel design for the micromachined gyroscope, in which electromagnetic driving is used, and the air damping in driving and sensing vibration mode is mainly slide-film damping. The former helps to obtain large driving force with constant ampl :tude, and the latter makes it possible to achieve high Q-values at atmospheric pressure. The mechanical coupling in the device is constrained significantly by using the decoupled design, and the tuning fork type design suppresses the interference from axial accelerations.System consideration, including the mechanical behavior, capacitive sensing, electronics, and noise sources of the device, were discussed. The natural frequencies and Q-values at atmospheric pressure are 2800Hz and 1613 for driving mode, and 3000Hz and 1613 for sensing mode, respectively. The expected noise equivalent rate is 0.123.The device was fabricated using silicon bulk mioromachining processes. The rootingeffect and marginal distortion of the structure in Deep Reactive Ionic Etching (DRIE) process were investigated.An equivalent circuit model of the device was built and used to simulate the behavior of the device, which is in good accordance with the analytic result. The interface circuit for the device was designed, tested, and applied to measure the device.At atmospheric pressure, the device is packaged and the performance was tested. The measured resonant frequencies and Q-values are 2906Hz and 1004 for driving mode, and 2996Hz and 522, 3033Hz and 421 for both sensing proof masses vibration modes, respectively. The sensor obtained a scale factor of 9.8mV/s, and a non-linearity of 0.43%. The noise equivalent angular rate and Zero Rate Output (ZRO) are and 144?/h, respectively.The analyzed and measured results show that the device designed in this dissertation has achieved high Q-values and sensitivity at atmospheric pressure, low mechanical coupling and thermal noise, with the interference from axial accelerations suppressed effectively. The device has shown its potential in some practical applications.
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