Journal of the Microelectronics and Packaging Society

Conventional two dimensional (2D) scaling is nearing physical limits, driving adoption of through-glass via (TGV) for three dimensional (3D) integration to maintain AI packaging performance. Glass interposers with embedded TGVs provide high-density vertical interconnects, lowloss RF paths, and improved thermal stability, overcoming silicon and organic substrate constraints. This review surveys established and emerging TGV fabrication methods and recent experimental progress. Selective laser-induced etching (SLE) offers precise 3D microstructures with controllable taper and high selectivity, ensuring reliable via formation with minimal thermal damage. Laser-induced deep etching (LIDE) enables high-speed, high-precision processing on large panels without microcracks, suitable for mass production of uniform, high-aspect-ratio vias. Femtosecond laser-assisted etching (FLAE) reduces thermal diffusion and yields ultrafine via arrays with smooth sidewalls. Quasicontinuous wave (QCW) laser etching supports near-vertical, low-taper vias at high speed, ideal for thin-glass substrates. Advances in TGV formation promise enhanced signal integrity, thermal reliability, and interconnect density in 2.5D/3D AI packaging.

Keywords Through-glass via (TGV), Artificial intelligence (AI), Laser drilling, Chemical etching