Ultra-thin glasses for semiconductor packaging

Abstract

Glasses are homogeneous, many glasses have excellent dielectric properties at GHz frequencies and some have thermal expansions (CTE) which are close to silicon. Ultrathin glasses (UTG) with thicknesses of 25 μm to 200 μm (0.001 to 0.0079 inch) offer numerous options for packaging, integration and co-processing in semiconductor manufacturing processes. We introduce SCHOTT UTG including paths to further improve their mechanical stability and strength. We use laser ablation in 50μm thick glass and show via fabrication with a potential of mass manufacturing with via diameters of 30μm, 38μm pitch and a position accuracy of +/− 1μm. The structures are metallized using sputtering and electroplating which leads to hermetic, tight conducting through glass-vias (TGV).