Research on sintering process of conductive silver wire based on dry aerosol jet printing

The effects of different sintering methods and process parameters on the microstructure and electrical conductivity of conductive silver wires produced by dry aerosol jet printing were investigated. By using a self-developed jet printing system, the area shrinkage rate was defined as the ratio of the change in the average cross-sectional area of the conductive silver wires before and after sintering to that before sintering, and the resistivity change rate was defined as the ratio of the change in resistivity to that before sintering. The forming effects of substrate heating and non-heating were analyzed, and the outcomes of Muffle furnace sintering and laser sintering were compared and analyzed. Experiments demonstrate that substrate heating reduces the cross-sectional area and porosity of conductive silver wires, effectively suppressing overspray. Under sintering conditions at 200 °C in a Muffle furnace, the shrinkage rate increases from 4.48% to 7.45% within 10 ~ 30 min, while the resistivity change rate rises from 74.17% to 92.48%. The minimum resistivity reaches 17.79 μΩ·cm. When the laser power for laser sintering is set to 0.7 mW, and the laser scanning speed is at 5~15 mm/min, the shrinkage rate decreases from 4.24% to 2.11%; the resistivity change rate decreases from 86.74% to 85.46%, and the minimum resistivity reaches 24.82 μΩ·cm. Energy input promotes the agglomeration and bonding of silver nanoparticles, enhancing line density. Laser sintering, leveraging its advantage of localized rapid heating, prevents extensive oxidation of oxygen-sensitive metals and silver wire breakage and detachment.