Xu Yingyu, Liu Shuibin, He Chunhua, Wu Heng, Cheng Lianglun, Huang Qinwen, Yan Guizhen
School of Computer, Guangdong University of Technology, Guangzhou 510006, China.
Science and Technology on Reliability Physics and Application Technology of Electronic Component Laboratory, China Electronic Product Reliability and Environmental Testing Research Institute, Guangzhou 510006, China.
Micromachines (Basel). 2023 Oct 20;14(10):1956. doi: 10.3390/mi14101956.
MEMS gyroscopes are widely applied in consumer electronics, aerospace, missile guidance, and other fields. Reliable packaging is the foundation for ensuring the survivability and performance of the sensor in harsh environments, but gas leakage models of wafer-level MEMS gyroscopes are rarely reported. This paper proposes a gas leakage model for evaluating the packaging reliability of wafer-level MEMS gyroscopes. Based on thermodynamics and hydromechanics, the relationships between the quality factor, gas molecule number, and a quality factor degradation model are derived. The mechanism of the effect of gas leakage on the quality factor is explored at wafer-level packaging. The experimental results show that the reciprocal of the quality factor is exponentially related to gas leakage time, which is in accordance with the theoretical analysis. The coefficients of determination () are all greater than 0.95 by fitting the curves in Matlab R2022b. The stable values of the quality factor for drive mode and sense mode are predicted to be 6609.4 and 1205.1, respectively, and the average degradation characteristic time is 435.84 h. The gas leakage time is at least eight times the average characteristic time, namely 3486.72 h, before a stable condition is achieved in the packaging chamber of the MEMS gyroscopes.
微机电系统（MEMS）陀螺仪广泛应用于消费电子、航空航天、导弹制导等领域。可靠的封装是确保传感器在恶劣环境下的生存能力和性能的基础，但晶圆级MEMS陀螺仪的气体泄漏模型鲜有报道。本文提出了一种用于评估晶圆级MEMS陀螺仪封装可靠性的气体泄漏模型。基于热力学和流体力学，推导了品质因数、气体分子数和品质因数退化模型之间的关系。在晶圆级封装中探讨了气体泄漏对品质因数影响的机理。实验结果表明，品质因数的倒数与气体泄漏时间呈指数关系，这与理论分析一致。通过在Matlab R2022b中拟合曲线，决定系数（）均大于0.95。驱动模式和传感模式下品质因数的稳定值预计分别为6609.4和1205.1，平均退化特征时间为435.84 h。在MEMS陀螺仪的封装腔室达到稳定状态之前，气体泄漏时间至少是平均特征时间的八倍，即3486.72 h。
