Capillary effect based TSV filling method

Via-filling is a critical and costly process of TSV fabrication and is usually realized by Cu-plating, CVD, etc. Liquid metal via-filling made by pressing solder from a melting solder pool into via holes faces problems of wafer breakage caused by pressure differential and cutting off solder-vias from the pool. A liquid bridge pinch-off effect based cutting-off method, together with a `wafer sandwich' structure, has the feasibility to solve the above problems faced by the pressure assisted liquid metal via-filling approach.