MEMS陀螺仪器件级真空封装技术  

Device level vacuum packaging technologies of MEMS gyroscopes

作　　者：施芹[1] 苏岩[1] 裘安萍[1] 朱欣华[1] 

机构地区：[1]南京理工大学MEMS惯性技术研究中心,江苏南京210094

出　　处：《光学精密工程》2009年第8期1987-1992,共6页Optics and Precision Engineering

基　　金：国家自然科学基金资助项目(No.10572039;No.10772086);江苏省青蓝工程支持计划项目;南京理工大学科研基金资助项目(No.XKF09004)

摘　　要：为进一步提高MEMS陀螺仪的品质因数及其稳定性,研究了MEMS陀螺仪器件级真空封装的高真空获取技术和真空保持技术。以Z轴MEMS陀螺仪动力学方程为基础,分析了MEMS陀螺仪的误差信号与品质因数之间的关系,并采用稀薄气体动力学分析具有高品质因数陀螺仪的空气阻尼。对早期真空封装陀螺仪品质因数的变化曲线进行了分析,得出了腔体内残余气体是品质因数下降的主要原因。采用程序升温脱附质谱分析法(TPD-MS)分析陶瓷管壳和金属盖板的放气特性,并选用了合适的吸气剂。最后,改进了器件级真空封装流程。测试结果表明,采用改进的器件级真空封装的陀螺仪品质因数最高可达162660,约为早期真空封装陀螺仪品质因数的14倍,且在一年内的变化<0.05%。The high vacuum acquisition and vacuum maintenance of device-level vacuum packaging for MEMS gyroscopes are studied to increase their quality factors and stability. The relationship between error signals and quality factors is analyzed based on the dynamics equations of Z-axis MEMS gyroscopes and the air damping of gyroscopes with high quality factors is analyzed using rarefied gas dynamics theory. The changes of quality factor of an early vacuum packaged gyroscope are analyzed, and the result shows that residual gasses in vacuum cavity result in the decreasing of vacuum level. A temperature programmed desorption-mass spectrometry （TPD-MS） is used to measure the contents of the evolution gases for the ceramic packages and the lids. According to the contents of trapped gases, the reasonable getter is chosen to absorb the gases and to keep the vacuum level of the cavity. Finally, the device-level vacuum packaging process is improved. The test results show that the quality factor of the gyroscope packaged with a new device-level vacuum packaging process is about 162 660, which is about 14 times those of previous vacuum packaged MEMS gyroscopes, and the change of quality factor is less than 0.05% within one year.

关 键 词：MEMS陀螺仪 真空封装 真空保持度 吸气剂 

分 类 号：TH824.3[机械工程—仪器科学与技术]