Fabrication of micron-sized nickel-silver core-shell particles by metal plating and its application in electrically conductive metal paste

Abstract

Electrical conductive metal paste is an important electronic materials using in broad applications. Silver paste is the one of the key product for solar cell application, but the raw material became expensive recently. The precious-metal-coating on a cheap material is a quite favorable strategy to get both low cost and good quality. This study suggests a simple method for the fabrication micro-sized nickel-silver core-shell particles. Micro-sized metal particles have no problem of high aggregation, low heat-resistance, and low durability. In this study, synthesis of core-shell particles with electroless silver plating was conducted by sonochemical method to avoid the aggregation of the particles and drop injection of plating solution for the efficient reaction. The exact injection rate of the silver plating solution is necessary for the fabrication of uniform particle synthesis. The morphology of the particles was analyzed by SEM and their chemical components were studied by EDX. Than the particles were examined for the application in metal paste. Characteristic of the composite metal paste, such as resistivity, morphology and shrinkage, were tested. This methodology can be used in other metal plating system just with exact injection rate of the metal solution. Composite metal paste using particles synthesized in this study is a possible substitute for metal paste with pure silver particles.