Conductive patterns by spray pyrolysis ofa self-reducing copper-amine complex ink

Abstract

Copper conductive films were prepared by spray pyrolysis method using copper-amine complex ink. Copper-amine ink was prepared by mixing amine solution and copper (II) formate. 0.35 M of Copper (II) formate was mixed with blend amines (diethanolamine, octylamine and dibutylamine) and 4 ml of solvent. Copper-amine complex ink was coated on PI substrate by spray pyrolysis at N2 atmosphere. The effect of types of amines and molar ratio of Cuf and amine were investigated at 200oC, 25 min. of annealing time under 6 LPM of N2 atmosphere. Moreover, the effect of spraying rate was examined by varying 0.53, 0.67 and 0.8 ml/min. The volume resistivity depends on above effect. The volume resistivity was decreased when using Cuf-DEA without alkylamine and decreasing spraying rate. The lowest resistivity of 2.691 µΩ.cm was obtained at 200 ºc using 1 Cuf : 0.12 DEA, 0.53 ml/min of spraying rate, 25 min of annealing time which is about 1.57 times higher than the resistivity of bulk copper. Moreover, the well sintered layer of the film was exhibited when decreasing spraying rate.