微系统结构均匀化模型参数的确定方法研究

在对3D封装微系统进行力学仿真建模时,硅通孔(TSV)和微焊点等结构的多尺度效应明显,需要划分大量网格,通过合理的等效处理可以降低网格数量,提高仿真效率。常规的方形柱等效使得结构失去原有微观形貌,仿真误差增加。为此,针对实际微观形貌提出了一种等效均匀化模型力学参数的确定方法。基于弹性力学方法,推导了圆柱形貌特征的TSV硅基板层力学参数的等效计算公式。对鼓球形貌特征的微焊点/下填料层均匀化模型提出了分层思想的力学参数确定方法。与现有方法相比,该方法考虑了微系统特征结构的真实形貌特征,计算效率更高,计算结果的一致性更好。

Study on Homogenization Model Parameters Determination Method of Microsystem Structure

Due to the obvious multi-scale effect of the through silicon via (TSV) and the microbump structure, a large number of meshes need to be generated during mechanical simulation modeling of 3D packaging microsystem. Resonable equivalent processing could reduce the mesh number and improve simulation efficiency. However, the actual microstructure shape may be lost, resulting in larger simulation errors when the conventional equivalent method of square column was applied. Thus, determination methods of the homogenization model parameters were proposed for actual microstructure shapes. Based on the elastic mechanics theory, the equivalent calculation methods of various material parameters of cylindrical structures such as TSV interposer layer were derived in this paper. Further, by using the derived results and based on the delamination idea, the equivalent calculation method of material parameters after homogenization of microbump/underfill layer with drum ball morphology was given. Compared with the existing methods, the proposed method considered the true morphological characteristics of microsystem structures, so the calculation efficiency was higher, and the consistency of the results was better.