Cutting flexible printed circuit board with a 532NM Q-switched diode pumped solid state laser

Abstract

The authors investigate the high-speed laser cutting of flexible printed circuit boards (PCBs) using a low M2 532nm laser to create features <40 microns in size. The use of flexible PCBs in portable electronics devices such as laptops, PDAs and mobile phones is increasing as such material offers advantages in terms of weight and volume over conventional PCBs. Typically a laminar structure of copper - polyimide - copper, less than 50 microns thickness, this material is difficult to cut conventionally being prone to tearing and delamination. Cutting of <50 micron thickness flexible PCB is investigated empirically using a low M2 532nm high average power Q-switched diode pumped solid state laser. Comparisons are made between different laser wavelengths including that of a 532nm frequency doubled laser and a fundamental wavelength 1064nm laser. Cutting speeds of >120mm/s are reported with a high quality kerf.