레이저유도플라즈마분광분석법을 이용한 연성회로기판가공공정의 시간적 계측

Temporal process monitoring of flexible printed circuit board using laser induced breakdown spectroscopy

  In the present study, the time evolution of laser induced plasma produced from single sided structure of flexible printed circuit board is characterized in terms of its temporally resolved spectral emissivity using the technique of laser induced breakdown spectroscopy. Using KrF excimer laser with the energy intensity of 82.6J/㎠, the temporal profiles of C₂ swan band from polyimide film and neutral copper from copper layer are studied for a time delay of 50㎱ from the beginning of the laser pulse under ambient pressure increasing by 200㎱. The measured decay times are 600.4㎱ and 486.4㎱ for C₂ swan band (516.5㎚) and neutral copper(521.8㎚) respectively. Finally, using the decay time data, the transition layer between polyimide and copper film is distinguished by their characteristic peak information with increased sensitivity.