The Effect of Cu Orientation on Fracture Location in Cu3Sn-Cu Interface Structure Under Monotonic Loading Condition by Molecular Dynamics Simulation

Abstract

Cracks at the soldering area during electromigration (EM) and isothermal ageing in solder joints has become a critical reliability issue with the development of electronic industry. Addressing to the fracture along the interface between Cu and CU 3 Sn, This paper studied its interface strength under mode-I and mode-II loading condition with the strain rate of 0.0027 pS−1 via molecular dynamics (MD) simulation. MEAM (modified embedded atom method) was used for modeling the interaction between Cu-Sn atoms, and simulation box size of $\mathbf{55} \mathring{\mathbf{A}}\times \mathbf{47.7} \mathring{\mathbf{A}}\times \mathbf{69.12} \mathring{\mathbf{A}}$ was used for investigation the properties of the model interface. Especially, this paper focus on the effect of orientation of Cu on the interface strength of CU 3 Sn-Cu interface structure. CSP (centro-symmetry parameter) was also analyzed for the better understanding of its dissipative mechanism. From the MD result, orientation of Cu has great influence on the CU 3 Sn-Cu interface strength under mode-I deforming, and CU 3 Sn-(001)Cu interface structure has a higher interface strength compared with others, while it have little effect under mode-II deforming condition.