Pi-Ying CHENG¹, Wen-Tse HSIAO², Chien-Kai CHUNG², Shih-Feng TSENG^2*, and Ien-Chang LIAO¹

¹Department of Mechanical Engineering, National Chiao Tung University, Hsinchu 30010, Taiwan
²Instrument Technology Research Center, National Applied Research Laboratories, Hsinchu 30076, Taiwan

(Received March 10, 2014; Revised June 24, 2014; Accepted July 8, 2014)

To accomplish an electrode patterning in large area, we present a high speed stitching technique used in an ultraviolet laser processing system and investigate the interaction between laser beams and indium tin oxide (ITO) thin films deposited on glass substrates. After optimizing the process parameters of the laser direct imaging (LDI) for the large-area electrode patterning, the ablated lines looked like regularly fish-scale marks of about a 40 μm diameter and a 120 nm depth around the processing path. The parameters includes the laser power of 1 W, the scanning speed of galvanometers of 800 mm/s, and the laser pulse repetition frequency of 50 kHz. Moreover, the resistance value of the ablated ITO thin film is larger than 200 MΩ that is electrically insulated from the other regions of electrode structure. LDI technology with UV laser beam has great potential applications in patterning on wafer or sapphire substrates and patterning a conductive layer deposited on the touch panels for semiconductor and optoelectric industries, respectively.

Key words: electrode patterning, high speed stitching technique, ultraviolet laser, indium tin oxide (ITO), laser direct imaging (LDI)

^*E-mail address: tsengsf@itrc.narl.org.tw