Microstructure and electrical property of laser-sintered Cu complex ink

We show that highly conductive Cu films are obtainable from Cu complex ink by laser sintering. The Cu inks, synthesized using Cu formate as a precursor, were spin-coated onto polyimide substrate and scanned by an ultraviolet laser at 355 nm. The blowing of N-2 gas into the irradiated area prevented the film from being oxidized and a minimum resistivity of 1.70 x 10(-5) SZ cm was obtained. The laser-sintered film, composed mainly of nanorods, exhibited a much tighter structure than the one achieved by the typical thermal process. Although the thermal-sintered Cu film had a better crystalline quality, the minimum resistivity values available with both methods were almost identical. This is attributed to the more compact microstructure induced by laser sintering. (c) 2014 Published by Elsevier B.V.