Scribing of ITO-coatings using a Q-switched Nd:YAG laser

This paper describes the results of optimising three process variables (control factors) to achieve a narrow line width in laser engraving of ITO conductive coatings using the Taguchi technique of experimental design. The laser used is a NEC Q-switched continuous wave (CW) Nd:YAG laser operating at a wavelength of 1.064 μm. The three process variables explored are: Q-switch frequency, speed of X-Y stage, and attenuator ratio of laser power. The various parameters were assigned to an L9 orthogonal array. The experiments were conducted with two repetitions each of which employs complete randomization. It was found that a narrow line width could be achieved with a Q-switch frequency of 25 kHz, scribing speed of 2000 mm/min, and beam attenuator setting of 35. A confirmation experiment of was carried out and the results fell within the predicted 95% confidence interval.