Room temperature sintering mechanism of Ag nanoparticle paste

Recently, the authors have developed a novel room temperature wiring method with Ag nanoparticle paste. In the present work, the sintering mechanism of Ag nanoparticle paste was clarified through analysis of the adsorption stability and the removal of the dispersant from the Ag nanoparticles. The Ag nanoparticles in the paste are protected by dodecylamine as a dispersant. This paste possesses a substantially long shelf life. When a printed line of Ag nanoparticle paste is dipped in a methanol bath, the methanol dissolves the dispersant allowing it to be removed from the nanoparticles, effectively. Ag nanoparticles are sintered within a short period, although the sintering is not uniform. Some Ag nanoparticles grow quickly and form networks by sintering necking. The other nanoparticles remain on the nano-meter scale. Large Ag particles and Ag skeletons continue to grow by absorbing very small nanoparticles. In addition, the effect of ethanol and isopropanol as treatment agents is found.