Abstract
In the last decade, there has been a rapid growth of development of thin film display techniques. In this research, we demonstrated the laser direct writing technique and reported experimental results of depositing copper from the coated copper formate thin film on glass. On the same way, silver acetate was utilized to deposit silver on glass substrate. Moreover, a technique of using frequency doubling solid state Q-switched Nd: YAG pulse laser direct writing from solid film of nano-sized silver on glass substrates was also presented in this study. First of all, crystallization of the copper formate was eliminated by adding proper amount of glycerol into the water solution. To suppress the surface tension of water against the glass substrate, ozone plasma was coated between the substrate and copper formate layer. Scan speed was accurately controlled by using LabVIEW program. Moreover, Nd: YAG laser pulses (532 nm) was focused and scanned on the glass substrates covered by copper formate film. With scan speed at 0.25 mm/s and appropriate laser pulse energy, copper lines were deposited after the copper formate decomposed thermally between 190 °C and 250 °C. The deposited 10.59 μm copper line showed good adhesion, good uniformity, and low edge roughness. However, Cu was oxidized easily under the high temperature of laser direct writing process. Therefore, silver acetate replaced copper formate because the activity of silver is less than copper. The electrical resistivity of silver lines after laser-treated process was not good enough because silver acetate was hard to be dissolved in solution. Finally, we utilized nano-sized silver colloids on glass substrates, through optimizing alignments and comparing the different experimental setup corresponding to different linewidths and electrical resistivities, the silver lines showed good adhesion, good uniformity, and low electrical resistivity. However, the silver line did not provide as low electrical resistivity as in bulk silver; therefore, we may try the electroless plating process to improve it in the future.