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

近年来，集成传感器和执行器（也称为微机电系统（MEMS））的新工艺技术、新设备概念和新市场出现了爆炸式增长。这种增长给微机电系统的计算机辅助设计（CAD）带来了新的挑战，其最终目标是准确，易于使用的行为模型，以捕获所有基本行为，并允许可预测的设计修改和优化。本研究探讨了在动态（冲击）载荷下可靠性设计指南的缺乏。这种载荷可以选择发生（例如，在卫星上发射的MEMS），也可以偶然落在坚硬的表面上。有证据表明，MEMS器件的小型可移动部件，如加速度计中的悬浮证明质量，在动态加载水平下会发生断裂，而基于准静态加载模型，器件预计能够承受动态加载水平。假设封装MEMS的惯性，当受到甚至适度的加速度时，提供了一个动能的储存器，然后可以作为声波传递给机械元件，并由于应力波加载而导致断裂。本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。通过建模程序来预测这些故障，并通过适当的设计，防止它们被开发出来。

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.