高精度一体化石英谐振加速度传感器及其关键工艺研究

High-accuracy resonant micro-accelerometer is the core device of inertial navigation, equipment attitude measurement and other systems, and it is strictly limited by international marketing. Therefore, the relative research is quite important for national defense and modern industry development. This project focuses on the research of high-accuracy quartz resonant accelerometer, especially on the new structure and new process development, to solve the problems of micro-assembling, low sensitivity, and process constraints of current quartz resonant accelerometer. Firstly, a laterally-sensing monolithic quartz accelerometer with micro-lever is proposed, and the collaborative modeling of micro-lever magnification factor and resonator's force-frequency coefficient is performed. The contradictory mechanism between micro-lever magnification factor and resonator's force-frequency coefficient is theoretically analyzed and optimized to obtain the optimal size of the sensor. The quartz micro fabrication technology based on Quartz on Silicon (QoS) and quartz dry etching is researched, and the key process parameters are studied to complete the fabrication of sensitive chips. By releasing the silicon substrate at the quartz sensitive structure, the problem caused by the mismatching of material property and micro bonding defect is eliminated. Finally, an integrated vacuum package of sensitive chip and resonant circuit is designed to perform the accelerometer for verifying theoretical results. Through the development of this project, it is hoped that breakthroughs will be made in developing new structure and new fabrication process of high-accuracy quartz resonant accelerometer, which will be of great significance in the fields of aerospace and high-end equipment manufacturing.

高精度谐振式微加速度传感器是惯性导航、装备姿态测量等系统的核心器件，受国际货运严格限制，开展此研究对国防和现代工业生产具有重要意义。本项目拟重点从新结构和新工艺等两方面进行高精度石英谐振加速度传感器的研究，解决目前石英谐振加速度传感器存在的微装配、灵敏度低、工艺约束等问题。首先，提出带有微杠杆的横向敏感一体化全石英结构，进行微杠杆放大倍数与谐振器力频系数的协同建模，理论分析两者的矛盾机理并进行优化，获得传感器最佳尺寸；提出以硅上石英（QoS）、石英干法刻蚀为基础的传感器加工工艺路线，研究关键工艺参数完成敏感芯片加工；通过释放石英敏感结构处的硅基底，消除硅-石英异质材料和键合微缺陷引起的精度损失；最后，设计敏感芯片与谐振电路的一体式真空封装，进行传感器性能测试，验证理论结果。通过本项目的开展，有望在高精度石英谐振加速度传感器的新结构和新工艺上取得突破，对航空航天、装备制造等领域具有重要意义。

微型高精度石英谐振加速度计是惯性测量系统的关键核心器件之一，实现运动载体加速度和位置信息的精确测量，其性能直接影响惯性测量系统的精度。本项目瞄准惯性测量和惯性导航对高性能加速度传感器的技术需求，开展了全石英谐振式加速度传感器的结构设计优化、微纳制备工艺、激振电路与传感器封装技术、实验测试等研究内容。.本项目根据石英音叉的受力变形状态，理论分析了石英音叉谐振器的固有频率、力频灵敏度与音叉尺寸之间的关系，获得了谐振器的最佳参数范围。通过对石英材料压电特性的分析，对其驱动电极进行分析和设计，并通过仿真验证了设计的合理性。.提出了平面推拉差动式全石英谐振加速度传感器结构，引入微杠杆提高标度因数。对输出端为复合结构的杠杆机构进行了理论分析和优化。引入应力分配梁进行惯性力的集中再分配，解决了非对称单杠杆与宽端面石英音叉连接带来的两根振梁内应力不匹配问题。.提出了基于QOS的石英干法刻蚀工艺，解决了单晶石英深干法刻蚀时难以一次成形的问题；提出了单晶石英贯穿式氟基湿法腐蚀的一体成型工艺，解决了全石英结构一体成型的上下表面晶棱残留问题。研究了单晶石英的氟基湿法腐蚀工艺，成功制备了形貌良好、性能稳定的传感器芯片。.提出了传感器的小型化一体式隔离封装方案，研究了高阻抗谐振器的起振原理，设计了传感器的起振方案，并制作了起振电路。设计小型化和高可靠性封装工艺，完成了传感器原理样机的制备。.测试结果表明，本项目研制的微型化高精度石英谐振加速度传感器样机达到了预期技术指标。有关研究成果发表论文12篇；申请发明专利8项，已授权7项；获得2项竞赛获奖；培养研究生3人。有关研究成果实现了专利权的转让，转让金额为85万元。研制的传感器样机应用于航天某研究所的产品验证中。