Laser direct write of active thin-films on glass for industrial flat panel display manufacture

Abstract

Patterning of ITO and other active layers on glass is necessary for the manufacture of most flat panel display technologies, including TFT-LCD, Plasma and OLED. Traditionally performed using wet-etch lithographic techniques, it has been demonstrated in recent years that an alternative indus-trial technique is to selectively ablate the thin-film layers with a Q-switched infrared laser. In this paper the authors investigate the latest industrial designs of Q-switched diode pumped solid-state la-sers that are enabling the uptake of this process as a viable manufacturing technique. They report on the design of the current and next generation of laser systems, the optical techniques employed to achieve direct write, and the versatility of the technique in application for thin layers as diverse as ITO, SnO2 and Molybdenum. The authors conclude that the application of laser direct write of thin films now presents a viable alternative to conventional lithographic techniques for displays manu-facture, and offers significant benefits in terms of flexibility, processing steps and cost.