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

S. C. Tam^a, Y. H. Chen^b, H. Y. Zheng^b, and W. L. Chen^c  
(a) School of Electrical & Electronic Engineering Nanyang Technological University, Nanyang Avenue, Singapore 639798  
(b) Gintic Institute of Manufacturing Technology
71 Nanyang Drive, Singapore 638075  
(c) Waterjet International Pte Ltd 202 Innovation Centre
Nanyang Avenue, Singapore 639798  
 

ABSTRACT
 
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 um. 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.

KEYWORDS: Nd:YAG laser, laser scribing, ITO-coating, Taguchi technique
 
Reprinted from Proc. of SPIE, Vol. 3184 (1997), 186-194