Investigating the Sintering Process and Mechanical Properties of Nano-copper Particles Coupling Particle Packing Modeling with Molecular Dynamics Simulation

The nano-copper particles are widely used in the sintering processes of packaging wide bandgap semiconductors. Despite the significant success in the industry, the mechanism bridging the sintering process to the mechanical properties of sintered nano-copper is not yet well-modeled. In this paper, the impacts of different sintering temperatures and initial porosities caused by different stacking patterns on the uniaxial tensile performance of the sintered layer were studied via a molecular dynamics approach. Two stacking patterns, simple cubic and face-centered cubic, were simulated, respectively. Evolution of their structure at temperatures of 300, 400, 500, and 600 K were simulated as the sintering process. Afterward, the sintered structures were subjected to uniaxial tensile with rates of 0.01 and 0.04 Å/ps at different temperatures to compare the mechanical properties. The results show that the sintering rate and density of the sintered structure increase with a higher temperature. However, the tensile strength of the sintered structure is less relevant to the difference in stacking pattern. This study proves that porosity has a greater effect on sintering quality.