Parametric optimization of Nd–YVO4 laser for straight scribing on silver nanowire based conductive thin films by Taguchi method

Abstract

This study presents parameter optimization of laser scribing on silver nanowire based conductive thin films and a high-precision Nd–YVO4 (wavelength, 532 nm) laser is used to perform scribing experiments to replace the traditional wet etching process. The laser beam is directly focused on conductive thin films and vaporizes the silver nanowire which is coated on the thin film; consequently it is a non-polluting processes. The main objective of this study is to perform laser scribing experiments to cut off the silver nanowire on the thin film without damaging the flexible PET (Polyethylene terephthalate) substrate. To achieve the desired scribing linewidth, the total degree of freedom (dof) of each factor was calculated without considering the interaction effect among the different control factors. In addition, the Taguchi method was used to study the parameters optimization of the laser scribing experiments. The laser power, laser frequency, focusing position and scribing speed were selected as the four main control factors and the optimum parameters were determined by orthogonal array, main-effects analysis and the analysis of variance theory in the Taguchi method. Under the analysis of 95% CI (Confidence Intervals), the results showed that the validation of the scribed linewidth according to the optimum parameters is correct and this experimental model is reasonably accurate.