Sintering of Metallic Core-Shell Nanoparticles: Molecular Dynamics Insights

Core-shell nanoparticles (CSNPs) have attracted considerable attention as interconnect materials for advanced electronic packaging. Their compositional and structural flexibility have enabled a balance among electrical and thermal conductivity, oxidation resistance, material cost, and low-temperature sinterability. This review summarizes recent progress in the sintering behavior and mechanical performance of CSNPs, with particular emphasis on atomic-scale mechanisms revealed by molecular dynamics (MD) simulations. The roles of core-shell interfaces, shell thickness, particle size, sintering temperature, external pressure, and processing atmosphere in atomic diffusion, neck formation, defect evolution, pore elimination, and densification are systematically discussed. Current limitations associated with simulation time and length scales and the accuracy of empirical potentials are discussed. Future developments are expected to involve machine-learning interatomic potentials, integrated modeling of MD, phase-field modeling, finite-element analysis, large-scale multiparticle simulations, and extension toward compositionally complex and high-entropy alloy (HEA) NPs. These advances may provide a more reliable framework for understanding sintering mechanisms and guiding the rational design of high-performance nanoparticle interconnect materials.