Effect of flux on the wetting of autocatalytic Ni-Cu-P by In-Sn solder

This study applied wetting balance to investigate the effect of different fluxes on the wetting of Ni-Cu-P deposit by the In-Sn solders. The fluxes investigated are dimethylammonium chloride, stearic acid plus dimethylammonium chloride, and L-glutamic acid. Wetting time, interfacial tension, contact angle, and maximum wetting force were estimated from the wetting experiments. The experimental results indicated that flux affects the wetting kinetics rather than the wetting thermodynamics. Flux significantly affects the wetting time but not the contact angle between the Ni-Cu-P deposit and liquid In-Sn solders.