Tuning the Electrical Resistivity of Conductive Silver Paste Prepared by Blending Multi-Morphologies and Micro-Nanometers Silver Powder
Abstract As an important interconnection material in electronics, conductive silver paste has attract much research interest in chip packaging and printed circuit board due to its predominant properties like high conductivity and flexible interconnection. In this paper, the silver nanoparticles, the silver sphere particles and flake silver powder are fabricated by various methods. Different proportions of silver powder are selected to prepare micro-silver paste and mn silver paste (fabricated by silver nanoparticles : sphere particles : flake silver powder=1:1:1). Compared to traditional silver paste (containing 80wt% silver), the electrical resistivity of micro-silver paste containing 66.67wt% silver and cured at 200℃ for 45min in air is about (3.31±0.73)×10-5Ω·cm when the ratio of sphere particle to flake silver powder is 1:1, the resistance of silver paste doesn’t also increase dramatically after bending ten times. The addition of nano-silver particles can reduce the resistivity in lower temperature curing. The folding endurance of mn silver paste is comparable to that of micro-silver paste with sphere : flake=1:1.