基于晶体塑性有限元的铜-铜键合结构热疲劳行为研究OA

In the post-Moore's Law era,advanced 3D packaging is an important way to achieve continuous improvement in chip computing power and storage density.Cu-Cu bonding is a critical technology in 3D packaging,and one of its common failure modes is the thermal stress problem caused by the mismatch in coefficient of thermal expansion(CTE)between materials.Based on the crystal plasticity theory,a temperature effects constitutive model is developed and the parameters are calibrated.Based on the Voronoi algorithm,a 3D representative volume element(RVE)model of the Cu-Cu bonding is established,and the cumulative plastic strain energy density is introduced as a fatigue indicator parameter(FIP)to predict the fatigue crack initiation.The results show that both geometric discontinuities and dislocation pile-up effect can cause stress concentration,and there is a synergistic enhancement effect between them.The cumulative plastic strain energy density can effectively predict the four failure locations of Cu-Cu bonding,while impurities/defects in the bonding interface can accelerate the failure of Cu-Cu bonding.