Manufacturing of solder bumps with Cu/Ta/Cu as under bump metallurgy

This study investigated the feasibility of the multilayer Cu/Ta/Cu under bu mp metallurgy (UBM), deposited on AlN/Si where AlN is a thin film Interdiff usion study found that Ta is an appropriate diffusion barrier layer for the investigated solder bump structure. The temperature profiles and the flux compositions for solder reflow were also investigated, The Bw activators in vestigated include succinic acid, adipic acid, stearic acid, dimethylamine hydrochloride, and diethylamine hydrochloride, Among these, succinic acid w as the most appropriate in terms of wetting and cleaning.