In this paper, we demonstrate a low temperature, low pressure wafer level damascene compatible Cu-Cu thermocompression bonding using an optimized ultra-thin Copper-Nickel-Manganese based alloy layer, Manganin as passivation layer. Surface oxidation and roughness are the major bottlenecks in achieving low temperature and low pressure high quality Cu-Cu bonding. Manganin alloy have dual role of protecting Cu surface from oxidation even at higher temperature. ( © 2017 IEEE.