Glass interposer with high-density three-dimensional structured TGV for 3D system integration

An epoch-making glass interposer having high-density three-dimensional structured through glass via (TGV) was proposed and demonstrated. By using femtosecond laser-assisted etching and plating, TGVs including bent (crank-shaped) portions were successfully fabricated inside single silica substrate. The diameter of the TGV was 15 μm and the length was 2 mm, respectively. Therefore the aspect ratio becomes 130 approximately. The pitch between the neighbor TGVs was 40 μm. Since an arbitrary interconnects can be achieved by the interposer, higher performance and more design freedom three-dimensional (3D) system integration can be expected.