A mathematical model of the removal of gold thin film on polymer surface by laser ablation

The removal effects of an Au thin film on polymer sheets by an ultrashort-pulsed Nd:YAG laser ablation was studied. A theoretical model to describe the laser energy required F0 and optimal scanning velocity ν were presented and afterwards affirmed by experimental data. It is shown that the function of ν to lnF0 follows a linear relationship; an increase in laser flux F0 led to an initial rise in ablation rates Ra followed by a decline. Namely there exists a maximum ablation rate or a best removal effect and it corresponds to an ascertainable laser energy and beam scanning velocity. Using the optimized laser processing parameters the Au thin film could be completely removed and satisfactory cleaning was achieved. The analytical method and the results were taken as a guide for accurately determining the laser parameters and proper conditions for the practical utilization of micro processing of the thin film by laser-ablation.