全对称MEMS陀螺结构能够有效克服目前现有加工条件限制，抑制干扰力，提高器件环境适应性，从而大幅提升陀螺精度，是实现高性能微陀螺结构设计的突破口。本论文围绕高性能平面全对称陀螺结构设计与优化、三维全对称陀螺结构设计与工艺开展研究。在平面全对称陀螺结构设计方面，提出一种中心支撑四质量陀螺（CSQMG）结构方案。该结构通过N形梁、Y形耦合梁连接各个集中质量形成四质量环形谐振子，再与中心单支撑点的田字形支撑架连接实现，具备工艺容宽大、检测精度高、环境适应性好等优势。为充分发挥新结构性能，提出中心支撑四质量结构综合设计优化方法，按照结构优化、梳齿设计、版图设计三个层级对CSQMG进行了系统优化设计。优化设计后，CSQMG白噪声输出水平降至0.72°/h/√Hz，Allan方差降至0.12°/h（@100s），展现了导航级精度潜力。在平面全对称陀螺结构误差机理分析方面，将基于频响特性的结构参数辨识方法运用到MEMS多质量谐振器中，构建了最大误差小于1.74％的四质量环形谐振子12自由度动力学模型。在辨识实验中参照扫描电镜测量与有限元仿真结果，对参数辨识结果进行了小范围线性补偿。根据制造过程中0.5μm的最大误差和线性补偿后0.17μm的辨识结果最大偏差，该辨识方法具有较高精度。在三维全对称陀螺结构设计方面，借助平面全对称陀螺结构建模与仿真手段，对半球敏感结构进行了理论计算与仿真研究，推导了微半球敏感结构的极限精度，为微半球敏感结构加工提出了具体精度要求。使用理论计算方法（半球谐振子振动方程）与有限元仿真方法分别计算球形电极、平面电极、筒形电极三种电极方案电容量与振动过程电容变化量，为半球陀螺提供了多种可行方案。在三维全对称陀螺结构工艺研究方面，合作研制高温可视化可控压热成形设备，实现了1800℃以下（精度±1℃）101kPa以下（精度±0.1kPa）长时间控温控压，为半球热成形研究提供工艺条件。提出一种具有批量重复性的半模压热成形工艺方法，最大化利用了高温环境下石英玻璃的工艺特点，在满足工艺需求、保证批量一致性的基础上尽可能降低工艺成本，为下一代高精度/大量程微机电陀螺加工奠定了技术基础。
Fully symmetrical MEMS gyroscope can effectively overcome the limitations of current processing conditions, effectively suppress the interference force, improve the environmental adaptability of the device, and greatly improve the performance of the gyroscope, which is an important breakthrough in the design of high-performance micromachined gyroscope structure. This dissertation focuses on the design and optimization of high-performance planar fully symmetric gyroscopes and the research on the design and process of three-dimensional fully symmetric gyroscopes.In the aspect of the design and optimization of planar fully symmetric gyroscopes, the scheme of the Center Support Quadruple Mass Gyroscope (CSQMG) is proposed for the first time. By connected N-shaped serpentine beams and Y-shaped coupling beams to four lumped masses and supported by a single anchor square-shaped support frame, a quadruple mass circle resonator is formed, that possess the advantages of large process capacity, high detection accuracy, and good environmental adaptability. In order to give full play to the new design, this dissertation proposes a systematic optimization method for the comprehensive design of the new structure, according to three levels, that is structure optimization, comb tooth optimization and layout optimization. After optimization, experiments show Allan variance stability 0.12°/h (@100s) and the white noise level about 0.72°/h/√Hz, which means that the CSQMG possesses great potentials to achieve navigation grade performance.In structural error mechanism analysis of the planar fully symmetric gyroscopes, the method of structural parameter identification based on frequency response is applied to MEMS multi-mass resonator for the first time. The 12-DOF dynamic model of the quadruple mass circle resonator with a maximum error less than 1.74% is constructed through reasonable model simplification, moment operator derivation, static equation solution, Moore method flexibility calculation, and vibration mechanics simplification. In the identification experiment, referring to the SEM and finite element simulation results, the parameter identification results were linearly compensated for a small range. The maximum error of ± 0.5μm in the manufacturing process and the maximum deviation of 0.17μm after compensation confirmed the precision of the identification method.The research on the modeling and simulation of planar symmetric gyroscopes provides sufficient technical means to construct the sensitive structural model of the micro-hemispherical gyroscope. In the aspect of three-dimensional fully symmetric gyroscope, the theoretical calculation and simulation of hemispherical sensitive structures are carried out by means of the above-mentioned methods, and the ultimate precision of the sensitive structures of the hemispheres is deduced, which puts forward the specific precision requirements for the processing of sensitive structures in the hemispheres. The theoretical calculation (by the vibrational equation of the hemispherical resonator) and the finite element simulation are used to calculate the capacitance and the capacitance variations of the three type electrodes, that is the spherical electrode, the planar electrode and the cylindrical electrode, respectively, providing various feasible solutions for the hemispherical gyroscope.In the research of three-dimensional fully symmetric gyroscope technology, a high temperature (below 1800℃) furnace equipment with visible internal workspace and adjustable pressure range (less than 101kPa) is designed and applied to monitor the whole process, which provides sufficient conditions for hemispherical thermoforming studies. For the first time, a semi-molded thermoforming process with batch reproducibility is proposed to maximize the technological characteristics of fused quartz under ultra-high temperature. Based on meeting the process requirements and ensuring batch consistency, the process cost is reduced to provide sufficient support for subsequent process steps. This research laid the technical foundation for the next generation of high-precision /large-scale MEMS gyroscopes.
