Surface Roughness Dependence of Inkjet Printing of Ag Nanoparticles

This report describes dependence of the inkjet printing on the surface roughness of normal PI film, ultra-smooth PI film, and polished Si wafer. The printing line width and LER are discussed by the line spreading constraint due to the limited volume of the droplet, vaporization of the solvent by the substrate temperature, the contact angle of the ink, and the surface roughness of the substrate. It is also shown that the minimum line width of ~21um is achieved on the Si wafer. Furthermore, the optimization of the substrate temperature for sintering of Ag nanoparticle is discussed.