Qualification of 1030 nm ultra-short-pulsed laser for glass sheet treatment in TGV process

Glass sheets with ~ 0.1 mm thickness are a promising material from which interposers for high density chip packaging can be produced due to its electrical and mechanical properties. For successful application in microelectronics, it is necessary to develop a way of efficient, high-speed production of interconnecting holes through such glass substrate, socalled through glass vias (TGVs). One of the most promising technique is Laser-Induced Deep Etching (LIDE), where picosecond laser is used to modified particular areas on the glass substrate. Then, using wet etching process, the area exposed to the laser will be etched more quickly than unexposed area. However, effective and large-scale glass modification often requires use of high-energy pulsed UV laser source, which unnecessary complicates the whole application. Here we present effective preparation of treated glass substrate using Yb:YAG laser at its fundamental wavelength 1030 nm, which is capable to overcome such disadvantage. We induced 5-15 m diameter regular affected areas on ~100 m substrate at various pitch, enabling scaled-up production of precise TGVs.