SGER: Guidelines for Computer-Aided-Design of Dynamically Reliable MEMS

近年来，新的工艺技术、新的器件概念以及集成传感器和执行器(也称为微电子机械系统(MEMS))的新市场呈现爆炸性增长。这种增长给MEMS的计算机辅助设计(CAD)带来了新的挑战，最终目标是准确、易于使用的行为模型，以捕捉所有基本行为，并允许可预测的设计修改和优化。这项研究调查了在动态(冲击)加载方面缺乏可靠性设计指南的问题。这种加载可以选择发生(例如，在卫星上发射的MEMS)，也可以通过意外跌落到坚硬表面来实现。有证据表明，MEMS器件的小可移动部件，如加速度计中的悬置质量块，在基于准静态载荷模型的动态载荷水平上经历了断裂。假设封装的MEMS的惯性，即使受到适度的加速，也提供了一个动能储存库，然后这些动能可以作为声波传递到机械元件，并由于应力波加载而导致断裂。这个项目通过使用数值分析来建立预期行为来检验这一假设的有效性。为了证实这一点，正在对硅微结构进行应力波加载的实验研究。正在开发预测此类故障并通过适当的设计防止其发生的建模程序。

In recent years, there has been an explosive growth of new process technologies, new device concepts, and new markets for integrated sensors and actuators, also referred to as micro-electro-mechanical systems (MEMS). This growth has led to new challenges for computer-aided-design (CAD) of MEMS, with the ultimate goals being accurate, easy-to-use behavioral models that capture all the essential behavior, and permit predictable design modifications and optimization. This research investigates the lack of design guidelines for reliability with regard to dynamic (shock) loading. Such loading can occur either by choice (for example, MEMS launched on satellites), or by accidental drops onto hard surfaces. There is evidence that the small moveable parts of MEMS devices, such as suspended proof masses in accelerometers, experience fracture from dynamic loading levels which the devices are expected to withstand based on quasi-static loading models. It is hypothesized that the inertia of a packaged MEMS, when subject to even modest acceleration, provides a reservoir of kinetic energy which can then be transferred to the mechanical elements as acoustic waves, and cause fracture due to stress wave loading. This project examines the validity of this hypothesis by using numerical analyses to establish expected behavior. For confirmation, experimental studies of subjecting Si microstructures to stress-wave loading are being made. Modeling procedures to anticipate such failures, and by proper design, prevent them are being developed.