Laser processing of thin flex glass for microelectronic, OLED lighting, display and PV applications

The feasibility of a picosecond laser for cutting and drilling thin flex glass (TFG) substrates is presented. A 50W Trumpf (TruMicro5x50) laser, providing 6ps pulses at the maximum pulse repeti-tion frequency of 400kHz, is used for processing 50μm and 100μm thick AF32®Eco Thin Flex Glass. The cutting and drilling processes are carried out using three laser wavelengths: 1030nm, 515nm and 343nm. The results show that the effective cutting speeds of up to 220mm/s can be obtained with the 1030nm wavelength but the quality of the laser cuts at this wavelength is rather poor. The best quality cuts are obtained with the 343nm wavelength. However, only cutting speeds of up to 40mm/s can be achieved at this wavelength. The 515nm wavelength, meanwhile, provides rela-tively good quality cuts with heat-affected zones (HAZ) of <40μm at moderate cutting speeds of up to 100mm/s. This paper also reports the use of the 343nm and 515nm wavelengths for drilling micro-holes (with inlet diameters <100μm) in the TFG substrates. Drilling speeds of up to 20holes/s were obtained with the 515nm wavelength, whereas the 343nm wavelength enabled drilling of high-quality micro-holes with speeds of up to 5holes/s. Optical microscope images and SEM images of the cuts and micro-holes are presented.