Advanced techniques in quartz wafer precision processing: Stealth dicing based on filament-induced laser machining

This research aims to achieve the high-quality and high-efficiency processing of quartz crystal through cutting experiments performed on quartz wafers, leveraging the capabilities of an ultraviolet (UV) femtosecond laser (fs-laser). The study integrates two crucial techniques, filament-induced laser machining (FILM) and stealth dicing (SD), to introduce an innovative approach named stealth dicing based on filament-induced laser machining (SDFILM). Using a harmonic generator, a conventional ∼1030 nm, 270 fs infrared (IR) fs-laser is transformed into a ∼ 343 nm UV fs-laser, enabling FILM on quartz wafers. Then, following a systematic investigation of laser parameters and processing variables on the machined quartz grooves, the optimally machined grooves take on a distinctive "Y" shape and yield effortlessly upon gentle mechanical force, akin to SD. Finally, an optimized laser focus strategy is introduced, resulting in a near-vertical "|" type cutting pattern on the quartz wafers. This research serves as a new method in the field of quartz processing, shedding light on new possibilities in the precision manufacturing of hard and brittle crystal materials.