In this paper, experimental procedures are developed to measure the tensile mechanical property of ultra thin Copper (Cu) wire (=1mil) before and after electric flame-off (EFO). Characteristics of free air ball (FAB), heat affected zone (HAZ) and as-drawn wire on 99.99% Cu wire have been carefully investigated by nanoindentation, microhardness and self-design pull test fixture, respectively. A secondary EFO technique has been conducted to reduce the strength of Cu wire and increase the bondability. The determined accurate material properties can then be applied to finite element analysis (FEA) for further reliability studies. A series of comprehensive parametric studies were conducted in this research.