은 나노입자의 합성과 이를 활용한 도전성 페이스트의 제조

Abstract

Recently, metal nanoparticles have an attractive attention because they have superior properties to other nano-sized particles, such as their electrical conductivities, optical properties, catalytic activity, and magnetic properties. Above all things, silver particles are an important substance of conductive inks, pastes and adhesives for various electronic devices. Therefore, it is necessary to develop a simple and effective synthesis method of nano-sized silver particles on a large scale. Recently, one-dimensional (1D) silver nanostructures have been extensively studied because the rod-like silver particles have an dvantage for adhesive strength on a substrate in silver electrode. It is also possible to reduce the temperature for heat treatment by application of nano-sized silver particles. In this work, nano-sized silver particles were prepared by the chemical reduction method using surfactants. The effect of surfactants on the morphology of the prepared silver nanoparticles was investigated and we intended to synthesize a rod-like silver particle with high aspect ratio using nano-sized silver seeds prepared by the chemical reduction method. The molar ratio of surfactants and silver nitrate was controlled to prepare the rod-like silver particles. lastly, silver paste using nano-sized silver particles were prepared. Microstructures and related specific resistance of metallized silver thick films with sintering temperatures were investigated. As a result, this study demonstrated that the morphology of silver nanoparticles was changed with various experimental conditions, i.e, kind of surfactants, For example, the shape and size distribution of silver nanoparticles are strongly dependent on the molar ratio of PVP/AgNO3 and SDS/AgNO3. Rod-like silver particles were also prepared by using a nano-sized silver seeds. When the molar ratio of silver nitrate and CTAB was 0.5, the rod-like silver particles were obtained. In addition, When the molar ratio of silver nitrate and SDS was 0.1, rod-like particles were formed with a mean aspect ratio of from 5 to 12. Lastly, silver paste prepared from nano-sized silver particles showed the low electrical resistance and sintering temperature.