Microstructure Formation on Glass Substrates for High-productivity Fabrication of Micro-vias Using 248 nm Excimer Laser

High-productivity fabrication of micro-vias in glass substrates is required for post-5G highfrequency signal interposers.This paper describes the fabrication of high-quality micro-vias with a high aspect ratio by ablation using a 248 nm excimer laser.To clarify the details of the ablation process, we investigate the surface microstructure generated by excimer laser irradiation.The results indicate that laser irradiation produces a surface microstructure that enhances the absorption of laser energy.