Temperature/ Humidity (T/H) stress experiments were designed to reproduce the pad corrosion defect and study the relationship between pad surface fluorine concentration and the formation of pad corrosion defects for different IC fabrication technologies. Results showed that T/H = 40/80 (i.e., at 40°C & 80% relative humidity, RH) was the condition with the most pad corrosion defects. The pad surface fluorine from wet clean and/ or the out gassing of the surrounding materials are proposed to be the major contributors for the formation of pad corrosion. Moreover, the pad surface oxide density and the integrity are other factors affecting the formation of pad corrosion defects.