Compressive failure mechanism of sintered nano-silver

As a promising packaging material for the third-generation semiconductor, the compressive behavior and failure mechanism of sintered nano-silver are vital for the reliability of packaging structure, which were investigated experimentally and numerically in the current study. The rate-dependent properties and microstructure evolution were determined by compression experiments under five loading rates at room temperature. Microscopically, the voids in the sintered nano-silver exhibit multi-scale distribution under specific sintering conditions, the corresponding failure mechanism is clarified by finite element analysis and scanning electron microscopy. Furthermore, a yield strength model with different porosity was proposed, which was adopted in the finite element analysis to investigate the microstructure evolution of sintered nano-silver. Eventually, the multi-scale simulation of the failure realized through the finite element model, the stress state of microstructure and the failure mechanism that is dependent on the multi-stage void were confirmed by the numerical simulation and experimental analysis. Microstructure of fracture section of sintered nano-silver: (a) morphology of Type I voids; (b) void closure of Type II voids; (c) compressive failure; (d) crack on the wall of Type I voids; (e) deformation of masonry-liked structure; (f) interfacial failure of Type II voids; (g) deformed void wall of Type I voids; (h) shear failure of sintered neck; (i) tensile failure of sintered neck; (j) Schematic diagram of compressive failure; (k) schematic diagram of shear fracture; (l) schematic diagram of tensile failure