Laser decal transfer of electronic materials with thin film characteristics

Abstract

We describe a novel technique, called laser decal transfer, for the laser forward transfer of electronic inks that allows the non-contact direct writing of thin film-like patterns and structures on glass and plastic substrates. This technique allows the direct printing of materials such as metallic nano-inks from a donor substrate to the receiving substrate while maintaining the size and shape of the area illuminated by the laser transfer pulse. That is, the area of the donor substrate or ribbon exposed to the laser pulse releases an identical area of nano-ink material which retains its shape while it travels across the gap between the ribbon and the receiving substrate forming a deposited pattern of the same dimensions. As a result, this technique does not exhibit the limited resolution, non-uniform thickness, irregular edge features and surrounding debris associated with earlier laser forward transfer techniques. Continuous and uniform metallic lines typically 5 micrometers or less in width, and a few hundred nanometers in thickness were fabricated by laser decal transfer. These lines are of similar scale as patterns generated by lithographic techniques. Once transferred, the lines are laser-cured in-situ using a CW laser beam, becoming electrically conductive with resistivities as low as 3.4 μΩ cm. This novel laser direct-write technique is a significant improvement in terms of quality and fidelity for directwrite processes and offers great promise for electronic applications such as in the development, customization, modification, and/or repair of microelectronic circuits.