Manufacturing and materials properties of Ti/Cu/Electroless Ni/solder bump on Si

This work attempted to fabricate the solder bump with the structure: Si/Ti/Cu/Electroless Ni/solder. The shear strength of the solder bump, with bump pad of 60 /spl mu/m in diameter, is around 15 g/bump prior to and after reflow. The solder bumps fractured at the solder. Humidity test at 85% of relative humidity at 85/spl deg/C and a high temperature treatment at 150/spl deg/C for 1000 h tend to downgrade the shear strength of the solder portion of the bump, yet not the interface. Both treatments enhance the growth of intermetallic compound (IMC) formed between Ni and solder. The barrier effect of electroless nickel deposit was investigated.