The thickness-ratio effects of Ni/Nb bi-layer electrodes were studied for power device applications. The reaction microstructure and electrical contact property were investigated after annealing at 1000 °C and compared with the results of an Ni electrode. Microstructure-related problems of the Ni electrode could be successfully resolved without sacrificing ohmic contact behavior by the addition of Nb to a Ni based electrode. Carbon precipitation on the electrode surface was reduced with increasing Nb thickness by the formation of carbides, which led to good adhesion between the electrode and a wiring pad. High shear strength of the bonded wire was also obtained by the elimination of the carbon precipitates on the electrode surface.