The compositions and growth kinetics of oxide films formed in air at 150°C to 300°C on the Cu-base
leadframe alloy were studied using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS),
and coulometric reduction technique. XPS and XRD studies confirmed that the oxide film consisted of
Cu/Cu2O (NiO)/CuO (NiO)/air. Cu2O was the major oxide and the thickness ratio of CuO/Cu2O was
approximately 0.28 at 150°C and 0.34 at 200°C. The kinetic studies on the oxidation showed that oxide
growth followed the parabolic rate law in the temperature range of 150°C to 300°C and the activation
energy for the overall copper oxidation was 71 kJ/mol. The activation energies for the cuprous oxide