Picosecond laser cutting and drilling of thin flex glass

AbstractWe investigate the feasibility of cutting and drilling thin flex glass (TFG) substrates using a picosecond laser operating at wavelengths of 1030nm, 515nm and 343nm. 50μm and 100μm thick AF32®Eco Thin Glass (Schott AG) sheets are used. The laser processing parameters such as the wavelength, pulse energy, pulse repetition frequency, scan speed and the number of laser passes which are necessary to perform through a cut or to drill a borehole in the TFG substrate are studied in detail. Our results show that the highest effective cutting speeds (220mm/s for a 50μm thick TFG substrate and 74mm/s for a 100μm thick TFG substrate) are obtained with the 1030nm wavelength, whereas the 343nm wavelength provides the best quality cuts. The 515nm wavelength, meanwhile, can be used to provide relatively good laser cut quality with heat affected zones (HAZ) of <25μm for 50μm TFG and <40μm for 100μm TFG with cutting speeds of 100mm/s and 28.5mm/s, respectively. The 343nm and 515nm wavelengths can also be used for drilling micro-holes (with inlet diameters of ⩽75µm) in the 100μm TFG substrate with speeds of up to 2 holes per second (using 343nm) and 8 holes per second (using 515nm). Optical microscope and SEM images of the cuts and micro-holes are presented