Synthesis of Thick-shell Cu@Ag Particles with Nanorod-shape Surface Morphology for Printed Electronics

This paper introduces a method to synthesize thick-shell Cu@Ag particles, with nanorod-shape silver wrapped on the copper surface after substitution and reduction reactions. The average size of silver nanorods is less than 50   nm and that of the copper particles is about 1 μm. The surface morphology, structure, and sintering properties of Cu@Ag particles were characterized in detail. The results show that the sintering temperature of thick-shell Cu@Ag is 127.5 °C, which is lower than that of Cu@Ag particles covered with island-shape and block-shape silver nanoparticles. The conductive ink was prepared by mixing it with resin paste, and the bulk conductivity of the conductive paste under different sintering conditions was investigated. The optimal -process parameters were chosen to conduct the printing of radio frequency identification (RFID) antennas. The farthest reading distances achieved by the ultra-high frequency RFID (UHF RFID) and the high-frequency RFID (HF RFID) were 9.4   m and 3.5   cm, respectively, which have good prospect of practical application.