Study on the shrinkage behavior and conductivity of silver microwires during electrostatic field assisted sintering

Abstract

An electrostatic field was applied to sintering Ag microwires to achieve a more compact structure and better conductivity. The shrinkage behavior of Ag microwires shows anisotropy, since bigger particle sizes, less micropores and smoother surfaces were observed in the direction of the electrostatic field in comparsion with the direction perpendicular to the electrostatic field, and the shrinkage rate of Ag microwires in the direction of electrostatic field improves about 2.4% with the electrostatic field intensity of 800 V cm−1. The electrostatic field assisted sintering model of Ag microwires is proposed according to thermal diffuse dynamics analysis and experimental research. Moreover, the grain size of Ag microwres sintered with electrostatic field increases with the electrostatic field intensity and reaches 113 nm when the electrostatic field intensity is 800 V cm−1, and the resistivity decreases to 2.07 × 10−8 Ω m as well. This method may overcome the restriction of metal wires which fabricated by the pseudoplastic metal nanoparticle fluid and be used as interconnects in nanoimprint lithography.