Effect of Ag coating on the oxidation resistance, sintering properties, and migration resistance of Cu particles

Ag-coated Cu particles (Cu@Ag particles) are highly anticipated bimetallic materials with wide electronic applications. However, it is still crucially challenging to obtain well-covered Ag shells and facilitate the synthetic process, and the sintering/migration behaviors of Cu@Ag particles are also poorly understood. In this study, we develop a facile Ag coating method for Cu@Ag particles with the assistance of double complexing agents. Electrochemical analysis reveals that the complexing effect can effectively reduce the potential difference of the Cu-Ag replacement reaction, and thereby improve the coating quality. Cu@Ag particles with compact and uniform Ag shells are obtained, with Ag contents as low as ~10 at%. The as-prepared Cu@Ag particles show significantly improved oxidation resistance and reliable sintering property. Moreover, the Cu@Ag particles exhibit superior ion migration resistance even better than both Cu and Ag particles under an oxygen-containing environment. The results could provide helpful basis for understanding the synthesis, sintering and migration processes of Cu@Ag particles. The comprehensive performance of Cu@Ag particles makes them a promising interconnected material in future electronic industry.