Optimization of Laser-induced Deep Etching for TGV Fabrication in Fused Silica

laser-induced deep etching (LIDE) is a promising technology for efficient and cost-effective through glass via (TGV) manufacturing. In this paper, the effect of nine independently adjustable parameters of LIDE on the TGV properties using ultrashort pulsed lasers was experimentally investigated. Furthermore, the influence of these parameters on the processing is explained by the mechanism of laser-material interaction in nonlinear optics. The taper and surface roughness of TGV with different processing parameters were characterized using optical microscopy and scanning electron microscopy. Further, the entire set of LIDE processing parameters were optimized in order to increase the selectivity and reducing the surface roughness without extra machining. This research can contribute to improving the maximum machinable density and interconnection performance of TGV and reducing the potential difficulty of metal filling in the glass interposer manufacturing process.