Multi-Layer Inkjet Printing of Ag Nanoparticle Inks and Its Sintering with a Near-Infrared System

This paper proposes process guidelines for inkjet printing with a multi-layer printing and near-infrared sintering. Ag nanoparticles and polymer substrate were used in this experiment. The lowest sheet resistance of 1.38 Ω/□ was achieved with four layers printing and 33-J/cm2 energy density. Meanwhile, the highest percentage of Ag bulk conductivity obtained was 8.97% with a 121-nm thickness and 33-J/cm2 energy density. This study examined the correlation among the operating conditions, thickness, and conductivity of the printed patterns fabricated by the drop-on-demand inkjet printing and near-infrared sintering system. A statistical methodology was conducted to identify the most dominant factor. The number of printing and energy density of near-infrared lamp were found to be significant factors affecting the thickness and conductivity of the printed layers, respectively. The findings of this study confirm the potential of inkjet printing and near-infrared sintering for fabricating thick layers for three-dimensional structure and flexible printed circuits.