Preparing high tap-density gold powders for printed electronics using seed-mediated synthesis

Due to excellent conductivity, oxidation resistance and low electrochemical mobility of gold itself, gold conductor pastes were widely used in electronic technology. However, the application of gold conductor pastes was limited by irregular morphology, wide particle size distribution, and low tap density of gold powders, which were usually prepared by the traditional liquid-phase reduction method. In this work, gold powders with high crystallinity and average particle size of 1.5 μm were prepared by seed-mediated synthesis. The as-prepared gold powders exhibited uniform size distribution, regular morphology, and intact crystal structure. Owe to proper particle diameter and extraordinary dispersion, the tap density of gold powders was as high as 10.2 g/cm 3 . Gold particles were tightly packed during sintering of paste, promoting densification of sintered body and improving the conductivity of thick film circuit. Gold powders with high tap density and crystallinity served as a fundamental material for high-performance electronic pastes, which exhibited significant application potential in precision sensor electrodes.