柔性电子封装膜-基结构的湿-热-机耦合作用下的竞争失效机理研究

Flexible electronic packaging is a multi-layered heterogeneous structure with existing many interface effects, which greatly affect its reliability due to complicated mechanical behavior and failure characteristics. In this proposal, the multi-scale characterization of material model parameters and the theory, experiment and numerical analysis framework for the failure mechanism of the multi-layered film-substrate structure in the flexible electronic packaging are established. Based on the multi-scale simulation and experimental method, the influence of the distribution of nano-conductive particles on the thermal, mechanical and electric properties are studied, and the performance control research and failure behavior characterization are made. By combining with the large deformation tensile test and the interface bonding performance experiment under different moisture and temperature environment, the study on hygrothermal induced material performance degradation and interface failure behavior are made. The cohesive zone model which can be used to describe the fatigue crack propagation on interfaces are developed; the parameters of the cohesive zone model between the film-substrate interfaces are obtained through a meso-scale parameter identification method. The mechanical models of the film-substrate structure are established; 3D hygrothermal-mechanical finite element method with considering interface cracking and slippage was developed; and then the mechanism of competing failure of the film-substrate structure are studied. Finally, by the research results of the above, the failure mode evolution of the multilayer film-substrate for the real packaging model are studied, so as to provide a guideline for the reliability evaluation, failure prediction, structure optimization design of the flexible electronic packaging.

柔性电子封装是多层异质结构，存在诸多界面效应，力学行为和失效特征复杂，极易诱致可靠性问题。本项目以柔性电子封装中的多层膜-基结构为研究对象，建立膜-基结构材料模型参数的多尺度表征、以及损伤失效演化的理论、实验与数值分析框架。基于多尺度模拟方法和实验手段，研究纳米导电颗粒分布对各向异性导电胶热、力、电性能的影响，并进行性能调控研究及失效行为表征；结合不同湿热环境下大变形拉伸试验和界面粘结性能实验，研究湿热环境诱致的膜-基材料性能退化规律和界面失效行为；提出描述界面开裂的疲劳内聚力模型，通过反演算法获得膜-基界面上的疲劳内聚力参数；建立膜-基结构力学分析模型，发展考虑界面开裂、滑移的三维湿-热-机有限元方法，研究膜-基结构失效模式的竞争机制。最后，利用上述成果研究真实封装模型多层膜-基结构失效模式的演变，为柔性电子封装的可靠性评价、失效预测以及结构优化设计提供依据。

柔性电子封装是多层异质结构，存在诸多界面效应，力学行为和失效特征复杂，极易诱致可靠性问题。本项目以柔性电子封装中的多层膜-基结构为研究对象，建立膜-基结构材料模型参数的多尺度表征、以及损伤失效演化的理论、实验与数值分析框架。基于多尺度模拟方法和实验手段，研究纳米导电颗粒分布对各向异性导电胶热、力、电性能的影响，开展导电胶材料性能的多尺度模拟；结合不同湿热环境下大变形拉伸试验和界面粘结性能实验，研究湿热环境诱致的膜-基材料性能退化规律和界面失效行为；提出描述界面开裂的疲劳内聚力模型，通过反演算法获得膜-基界面上的疲劳内聚力参数；建立膜-基结构力学分析模型，发展考虑界面开裂、滑移的三维湿-热-机有限元方法，研究基于改进贪心算法的膜-基结构界面的抗失效设计及膜-基结构的竞争失效模式。利用上述成果研究真实封装模型多层膜-基结构失效模式的演变，为柔性电子封装的可靠性评价、失效预测以及结构优化设计提供依据。