Evolution analysis of mechanical behaviours of through‑silicon via under thermal cycling load

As the key interconnecting structure of high-performance 3D chips, through‑silicon via (TSV) is of great significance to improve the packaging efficiency and computing performance of chips. However, under the increasingly complex and severe service environment, the failure mechanism of TSV is increasingly becoming a key problem hindering the development of 3D chips in the future. In this study, based on the crystal plasticity theory and with the help of literature data, the plasticity constitutive considering thermal expansion coefficient and temperature dependent plasticity parameters is constructed to simulate the mechanical behavior evolution mechanism of TSV under thermal cycling load. Results show that the mean Cu grain area increases from 55.42 μm² to 65.74 μm² after thermal cyclic loading, and the mean misorientation angle decreases from 41.34° to 35.53° correspondingly. The stability at the grain boundary is lower than that inside the grain, which can be proof by the resolved shear stress distribution, shear rate distribution and slip resistance distribution in different slip system. This study can be regard as the basis for the reliability research in extreme service environments, and has certain reference significance for promoting the development of 3D chips.