The effect of a reflow process and under bump metallurgy (UBM) systems on the growth of intermetallic compounds (IMC) of the 57Bi/43Sn and 37Pb/63Sn solder bump/UBM interfaces was investigated. The selected UBM systems were sputtered Al/Ti/Cu, sputtered Al/NiV/Cu, Al/electroless Ni/immersion Au, and Al/Ti/electroless Cu. Alloy electroplating method was used for solder bumping process. The microstructure and the composition of intermetallic compound (IMC) phases and their morphologies were examined using the scanning electron microscopy and the X-ray diffraction. The Cu6Sn5 eta'-phase IMC appeared on all Cu containing UBM cases with Pb/Sn and Bi/Sn solders and the Cu3Sn epsilon-phase was detected only with Pb/Sn solder bumps. The Ni3Sn4 IMC was found to be the main IMC phase between Ni and solder. The Ni-3 Sn secondary IMC was also detected on the electroless Ni UBM with PbSn solder after ten times reflow. Through the bump shear test, AI/NiV/Cu, Al/elNi/Au, and Al/Ti/elCu UBMs showed good stability with Bi/Sn and Pb/Sn solder in metallurgical aspect.