解耦z轴微机械陀螺的研制  

Development of decoupled z-axis micromachined gyroscope

作　　者：周浩[1,2] 苏伟[1] 刘显学[1] 唐海林[1] 

机构地区：[1]中国工程物理研究院电子工程研究所,四川绵阳621900 [2]中国工程物理研究院北京研究生部,北京100088

出　　处：《光学精密工程》2011年第9期2123-2130,共8页Optics and Precision Engineering

基　　金：国防预研基金资助项目

摘　　要：提出了一种检测模态解耦的z轴微机械陀螺,其检测模态被约束为1自由度振动,可抑制驱动模态的影响,降低不期望的检测模态偏置,并使用双质量结构在降低模态耦合的同时获得了较好的模态频率匹配。为满足驱动和检测模态自由度约束要求,使用了U形支撑梁。采用反应离子深刻蚀工艺制作了高深宽比结构层,获得了较大的验证质量,抑制了器件的机械热噪声,提高了陀螺分辨率。加工的陀螺面积为2 100μm×2 100μm,厚度为60μm。采用真空封装,获得了较高的机械品质因子。测试结果表明,驱动和检测模态的品质因子分别为2 000和1 800,机械热噪声为3.76(°)/h.Hz21。在±200(°)/s的量程内,刻度因子为21mV/(°).s-1,非线性度为1.426%FS,1h内测得零偏稳定性为0.057 9(°)/s。A decoupled-sense-mode z-axis micromachined gyroscope is presented.The sense mode is restricted to be only one degree of freedom for vibration,which restrains the effect from the drive mode and reduces the undesired sense mode bias.Using double masses allows both matched natural frequencies and decoupled modes.A U-shaped beam is utilized for meeting the requirements on the degrees-of-freedom of the drive and sense modes.In order to create a high-aspect ratio structure,a Deep Reactive Ion Etching（DRIE） process is used to achieve a larger proof mass,reduce the thermomechanical noise floor and provide high sensitivity.The area of the fabricated gyroscope is 2 100 μm×2 100 μm,with a thickness of 60 μm.The gyroscope is vacuum-packaged for a high mechanical quality factor.Measured results show that the drive and sense mode quality factors are 2 000 and 1 800,respectively,and the thermomechanical noise floor is 3.76（°）/h·Hz-12.The scale factor is 21 mV/（°）·s-1 in a range of ±200（°）/s,with a full-scale nonlinearity of 1.426 %FS.The bias drift is 0.057 9（°）/s over a 1 h measurement period.

关 键 词：微机械陀螺 机械解耦 反应离子深刻蚀 

分 类 号：TP212.1[自动化与计算机技术—检测技术与自动化装置]