Development of an Antioxidation Copper Paste with Self-Reducing Copper Formate and Molecular Dynamics Analysis of Sintering Mechanisms

This study investigates using an antioxidation copper particle-free paste, formulated with self-reducing copper formate, for Cu-Cu bonding in electronic packaging applications. The research highlights the oxidation resistance of copper formate compared to traditional copper nanoparticles (CuNPs) and its ability to generate CuNPs through thermal decomposition. Experimental results demonstrate that the sintering process benefits from releasing reductive gases during decomposition, improving joint quality with reduced porosity and enhanced mechanical strength at elevated temperatures. Molecular dynamics simulations further elucidate the sintering behavior of CuNPs, providing significant insights into pore collapse, atomic mobility, and neck formation. The findings indicate that increased temperatures enhance surface and bulk diffusion, facilitating robust particle connections. Overall, this work establishes the potential of copper formate for achieving reliable interconnects in semiconductor devices, paving the way for advancements in material formulations for direct copper–copper bonding.