Laser Curing of Digitally Printed Polymer-Silver Composite Conductive Tracks on Polycarbonate Substrates

In this article, we present an approach to fabricate conductive tracks on polymer substrates. Here, a digital printing process is used together with subsequent processing by a laser. For this purpose, a silver flake-based composite is printed onto a polycarbonate substrate using a jet-dispensing process. The printed tracks are then cured using a pyrometer-controlled laser beam source. The fabricated samples are analyzed for electrical resistivity and the cross-sectional area of the conductive tracks and compared to conventionally oven-cured samples. Four-point measurements and an optical measurement method are used for this purpose. Based on the resulting resistance, two different process regimes can be observed for the laser curing process. By using a laser instead of an oven for post-treatment, the achieved resistance of the conductive tracks can be reduced by a factor of 2. Moreover, the tracks produced in this way are more reproducible in terms of the resistance that can be achieved.