Abstract
Copper nanoparticles(CuNPs) are expected to be novel wiring materials because of low sintering temperature and low-priced ingredients. CuNPs are usable as a ink for wiring. This ink printed on a circuit board conducts electricity after proper heat treatment. However, CuNPs oxidize easily in the air. To prevent oxidation of CuNPs, additional costly process are needed such as atmosphere exchanging into an inert atmosphere. On the other hand, organic compounds have been used as protectors for CuNPs, but these non-metallic coverings often reduce conductivity of CuNPs. Hence, Cu-Ag nanocomposites(Cu-Ag NC) have been considered as an alternative method to prevent oxidation. In this study, Cu-Ag NC were easily synthesized under high concentration condition by using ultrasonic irradiation. Ultrasonic irradiation was easily process to combine metal nanoparticles with other materials. However, CuNPs and silver nanoparticles repel each other in a solvent because of positively charged particles. To change charge of CuNPs, oxidization of CuNPs is available. CuNPs were purposely oxidized, then synthesis of Cu-Ag NC became easily. Cu-Ag NC were reduced on a glass substlate, and electric resistivity of the sample were decreased from 2.267 Ωcm to 1.690 × 10^<-4> Ωcm.
