Gravure printing of conductive particulate polymer inks on flexible substrates

A roto-gravure printing technique has been developed for conductive lines on paper and plastic films. Rotary-screen-printing was used to make comparative prints. The inks contained metal particles in an organic medium and were cured in temperatures of 70-120 °C, limited by the substrate durability. The following conductor line properties were characterised for different substrates: resistance, yield as a function of line width, coil inductance, folding endurance, adhesion, printed antenna properties and maximum current density. A printed resistance down to ∼50 mΩ/□ was obtained, with conductor lines 4-7 μm thick. Minimum line resolution and resistance were affected by smoothness of substrates. Adhesion properties were adequate for the studied components.