Calegaro Daniel, Merli Massimiliano, Ferrari Giacomo, Mariani Stefano
Department of Civil and Environmental Engineering, Politecnico di Milano, Piazza Leonardo da Vinci, 32, 20133 Milano, Italy.
STMicroelectronics, 20007 Cornaredo, Italy.
Micromachines (Basel). 2024 Dec 8;15(12):1480. doi: 10.3390/mi15121480.
In the case of repeated loadings, the reliability of inertial microelectromechanical systems (MEMS) can be linked to failure processes occurring within the movable structure or at the anchors. In this work, possible debonding mechanisms taking place at the interface between the polycrystalline silicon film constituting the movable part of the device and the silicon dioxide at the anchor points are considered. In dealing with cyclic loadings possibly inducing fatigue failure, a strategy is proposed to optimize the geometry of an on-chip testing device designed to characterize the strength of the aforementioned interface. Dynamic analyses are carried out to assess the deformation mode of the device and maximize the stress field leading to interface debonding. To cope with the computational costs of numerical simulations within the structural optimization framework, a reduced-order modeling procedure for nonlinear systems is discussed, based on the direct parametrization of invariant manifolds (DPIM). The results are reported in terms of maximum stress intensification for varying geometry of the testing device and actuation frequency to demonstrate the accuracy and computational efficiency of the proposed methodology.
在反复加载的情况下，惯性微机电系统（MEMS）的可靠性可能与可移动结构内部或锚点处发生的失效过程相关。在这项工作中，考虑了在构成器件可移动部分的多晶硅膜与锚点处的二氧化硅之间的界面上可能发生的脱粘机制。在处理可能导致疲劳失效的循环加载时，提出了一种策略来优化用于表征上述界面强度的片上测试装置的几何形状。进行动态分析以评估器件的变形模式，并最大化导致界面脱粘的应力场。为了应对结构优化框架内数值模拟的计算成本，讨论了一种基于不变流形直接参数化（DPIM）的非线性系统降阶建模程序。根据测试装置的不同几何形状和驱动频率的最大应力强化来报告结果，以证明所提出方法的准确性和计算效率。
