All-round suppression of Cu 6 Sn 5 growth in Sn/Cu joints by utilizing TiO 2 nanoparticles

Both \(\text {TiO}_{2}\) and Cu nanoparticles, when added at the interface of the Sn/Cu joints during reflow soldering at 250 °C for 10, 60, 120 s and subsequent air cooling, are observed to reduce the growth of \(\text {Cu}_{6}\text {Sn}_{5}\) whiskers. Though both reinforcments reduce the vertical growth of intermetallic compound (IMC), only \(\text {TiO}_{2}\) could suppress the lateral growth of the compound. The solder saturation level with Cu at different reflow duration can influence final dimensions as well as morphology of IMC and occurrence of screw dislocation. The addition of \(\text {TiO}_{2}\), by intervening the mechanism of ostwald ripening during reflow can be utilized to enhance the solder-IMC bonding at interface.