热致封装效应对MEMS器件谐振特性影响的单元库模型

Modeling of Thermally Induced Package Effect on the Resonant Characteristics of MEMS Device

大量试验和数值仿真结果均已确认封装-器件的热失配对MEMS器件性能及可靠性有显著影响,即热致封装效应.然而迄今为止仍缺乏有效的物理模型对此加以系统描述.本文基于单元库法思想和节点法分析手段构建了MEMS热致封装效应的理论模型.通过对非器件结构如锚区、衬底等标准化单元建模,扩充了节点分析法在封装级MEMS仿真领域的应用.文中以常见MEMS基本器件和封装结构为例进行了研究,计算了热致封装效应对器件谐振特性的影响,并利用有限元仿真进行验证.最后讨论了封装级MEMS设计面临的挑战.

With the advance of the modeling of the device-level behaviors for the MEMS systems, characterizations for the package-level behaviors are becoming important. Results from either experimental or numerical studies have already validated the thermally-induced package effects on the performance and reliability of MEMS systems, while the theoretical descriptions for these effects are still lacked. In this paper, a theoretical joint model for the whole packaged MEMS system is established based on the Cell Library Concept and the Nodal Analysis Method to enable the package-level simulations for the designed devices. Cases of conventional package-device systems are studied to demonstrate the application of this joint model, and the results agree well with the FEM calculations. The challenges for the design of package-level MEMS systems are finally discussed.