Prediction of TSV wafer warpage based on hierarchical multiscale method

With the development of electronic packaging technology, wafer-level packaging is one of the representative advanced packaging methods which puts higher requirements on the integration density of the package, package size, and reliability. However, during the packaging processes, excessive wafer warpage is one of the crucial challenges to affect packaging reliability. The TSV wafer packaging structure presents typical multiscale characteristics, which poses a great challenge on the establishment of finite element models. To this end, a hierarchical multiscale approach is proposed in this paper and the effectiveness of the proposed method is verified. First, the rationale and computational process of the hierarchical multiscale approach is elucidated. Finite element model was established using the hierarchical multiscale method to simulate the warpage evolution during the TSV interposer manufacturing processes, and the simulation results agreed quite closely to the experimental results. Finally, the effect of the hierarchical multiscale approach on the accuracy of the model was investigated. The results of the study show that the computational error decreases significantly with the increase of the number of partitions for a comparable computational size. Compared with the experimental results, it shows that the method can effectively improve the predicting accuracy on wafer warpage. In addition, the developed hierarchical multiscale method is portable and can be applied to other packaging structure featuring with multiscale characteristics, providing a solution to the problem of large-scale electronic packaging.