Laser Cutting Process for FPCB

The application of lasers in the area of microelectronics is growing and diversifying to innovative technologies to enable the increased sophistication of their products. Lasers are employed in manufacturing processes as varied as semiconductor lithography, wafer dicing, and micro-welding via drilling and FPCB cutting. In particular, the laser ablation process is required in sophisticated FPCB cutting as the prior punching process incurs shearing and scratching. In this study, the laser cutting mechanism of FPCB was examined to solve problems related to surface debris and short-circuiting that can be caused by the photo-thermal effect. The laser cutting of PI and FCCL, which are base materials of FPCB, was carried out using a pico-second laser and adjusting variables such as the average/peak power, scanning speed, cycles, gas and materials. Using an alpha-stepper, it was possible to analyze the thermal effect, composition of the surface debris, and the ablation rate. Points which special attention should be paid are that a fast scanning speed, low repetition rate and high peak power are required for precision machining. Finally, useful data will result for the cutting of elaborately designed FPCBs for portable devices such as laptops, PDAs and mobile phones.