Structuring of micro line conductor using electro-hydrodynamic printing of a silver nanoparticle suspension

The generation of a fine pattern of metallic materials from suspensions is gaining significant interest because it is the key in the fabrications of displays and printed circuit boards. In our experiments, a silver nanoparticle suspension was first deposited onto a Kapton (R) polyimide film by using an electro-hydrodynamic printing system, including a guide ring and pin (nozzle)-to-pin (ground) electrodes. Then after thermal curing of the particles deposited, a conductor line as fine as 32 mu m in width and 0.3 mu m in thickness was obtained onto the film. The resistivity of the line was about 13 mu Omega cm. The pin type ground electrode was helpful in the deposit of the silver nanoparticle suspension along a specific direction. The guide ring repressed the chaotic motion of the jet and prevented the jet from digressing from the centerline. With the electro-hydrodynamic printing method, a nozzle (inner diameter: 140 mu m, outer diameter: 320 mu m) much larger than an ink jet nozzle could be used.