Picosecond laser cutting and drilling of thin flex glass

TLDR

We investigate the feasibility of cutting and drilling thin flex glass (TFG) substrates using a picosecond laser operating at 1030 nm, 515 nm, and 343 nm. We used 50 µm and 100 µm AF32®Eco Thin Glass sheets and studied laser parameters—wavelength, pulse energy, repetition frequency, scan speed, and number of passes—to achieve through cuts or boreholes. The study found that 1030 nm yields the fastest cutting speeds (220 mm/s for 50 µm and 74 mm/s for 100 µm), 343 nm provides the highest cut quality, 515 nm offers good quality with HAZ <25 µm (50 µm) and <40 µm (100 µm) at speeds of 100 mm/s and 28.5 mm/s, and both 343 nm and 515 nm can drill micro‑holes ≤75 µm in 100 µm TFG at up to 2 holes/s and 8 holes/s respectively, with cuts and holes illustrated by optical microscopy and SEM.

Abstract

We investigate the feasibility of cutting and drilling thin flex glass (TFG) substrates using a picosecond laser operating at wavelengths of 1030 nm, 515 nm and 343 nm. 50 μm and 100 μm 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 (220 mm/s for a 50 μm thick TFG substrate and 74 mm/s for a 100 μm thick TFG substrate) are obtained with the 1030 nm wavelength, whereas the 343 nm wavelength provides the best quality cuts. The 515 nm wavelength, meanwhile, can be used to provide relatively good laser cut quality with heat affected zones (HAZ) of <25 μm for 50 μm TFG and <40 μm for 100 μm TFG with cutting speeds of 100 mm/s and 28.5 mm/s, respectively. The 343 nm and 515 nm wavelengths can also be used for drilling micro-holes (with inlet diameters of ⩽75 µm) in the 100 μm TFG substrate with speeds of up to 2 holes per second (using 343 nm) and 8 holes per second (using 515 nm). Optical microscope and SEM images of the cuts and micro-holes are presented.