Robust design and model validation of nonlinear compliant micromechanisms
Robust design and model validation of nonlinear compliant micromechanisms
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DOI：
10.1109/jmems.2005.859190
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发表时间：
2006-02-01
影响因子：
2.7
通讯作者：
Howell, LL
中科院分区：
文献类型：
--
作者：
Wittwer, JW;Baker, MS;Howell, LL
尽管在微机电系统（MEMS）中使用柔顺性或弹性灵活性有助于消除摩擦、磨损和间隙，但众所周知，柔顺性MEMS对材料特性和特征几何形状的变化很敏感，从而导致性能上的很大不确定性。本文提出了一种设计阶段不确定性分析、模型验证和非线性MEMS鲁棒优化的方法，以考虑包括残余应力、层厚度、边缘偏置和材料刚度在内的关键工艺不确定性。以全柔性双稳微机构（FCBM）为例，证明了该方法可用于处理涉及非线性有限元模型的复杂器件。力-位移曲线的一般形状是通过比较不确定度预测和从原位力计获得的测量结果来验证的。提出了一种鲁棒设计，其中仿真表明，在感兴趣点的估计力变化可以从+/- 47 μ N减少到+/- 3 μ N。通过测量晶圆片上多个位置的第二稳定位置，实验验证了对工艺变化的灵敏度降低。
Although the use of compliance or elastic flexibility in microelectromechanical systems (MEMS) helps eliminate friction, wear, and backlash, compliant MEMS are known to be sensitive to variations in material properties and feature geometry, resulting in large uncertainties in performance. This paper proposes an approach for design stage uncertainty analysis, model validation, and robust optimization of nonlinear MEMS to account for critical process uncertainties including residual stress, layer thicknesses, edge bias, and material stiffness. A fully compliant bistable micromechanism (FCBM) is used as an example, demonstrating that the approach can be used to handle complex devices involving nonlinear finite element models. The general shape of the force-displacement curve is validated by comparing the uncertainty predictions to measurements obtained from in situ force gauges. A robust design is presented, where simulations show that the estimated force variation at the point of interest may be reduced from +/- 47 mu N to +/- 3 mu N. The reduced sensitivity to process variations is experimentally validated by measuring the second stable position at multiple locations on a wafer.