A Combined Ink Jet Printing/Photo-reduction Process for the Fabrication of μm-size Conductive Tracks

Abstract

Ink jet printing is a promising process for the production of cheap, flexible electronic circuits. Miniaturisation of such circuits to sizes smaller than currently attainable by conventional ink jet printing would present benefits in terms of performance, economics and the environment. Two laser-based techniques (selective laser ablation and photo-reduction) used in conjunction with ink jet printing to reduce feature size are demonstrated. Selective laser ablation of metallic silver tracks enabled feature sizes to be reduced to ∼5 μm, with good edge definition and little damage to glass substrates. Photo-reduction of organometallic silver salt deposits enabled features down to ∼10 μm, with no measurable heating of the substrate; enabling the use of a wide range of polymeric substrates. Both techniques show potential for reducing the feature size of ink jet printed deposits by an order of magnitude on flexible substrates.