Treballs Finals de Grau de Física, Facultat de Física, Universitat de Barcelona, Curs: 2016, Tutor: Pere Serra Coromina
One of the most used inks in printed electronics is silver paste, which is extensively used in screen printed circuits. In this work the feasibility of Laser-Induced Forward Transfer (LIFT) technique was investigated for transferring screen printing silver paste. It was possible to print several droplets at different laser pulse energies for a certain donor-acceptor gap. After that, two studies were carried out: the analysis of the deposited droplets and the characterization of the dynamics of the material transfer. An approximately linear trend in the radius-energy dependence was observed, and thicknesses of the printed droplets were of the order of a few microns. The transfer dynamics was characterized by means of a time-resolved imaging method, showing three different stages on the bubble evolution: bubble expansion, bubble burst and bubble retraction. Jet formation never took place as it happens in low-viscosity inks. Results in both experiments were conclusive and consistent with each other