Research on electroforming Ni-Fe alloy for MEMS

The relationship between the composition, coating microstructure and electromagnetic properties of electroforming Ni-Fe alloys was studied in this paper. And the optimal process parameters to obtain Ni-20%Fe deposition was as following: FeSO4·7H20 concentration was 6g/L; PH value of the solution was 2.5; current density was 3.5A/dm²; electrolyte temperature 55°C. The results indicate that the Ni-Fe deposit is bright and compact, the crystal-planes of the plating were (111), (220) and (200). Electrodeposited Ni-20%Fe has a strong paramagnetism effect with the smallest remanence of 0.5 emu, The coercivity show a monotonic decrease with increasing Fe content in deposit, and the saturation magnetization was only 10% of that of the IJ85 permalloy, which proved that the electroformed Ni-20%Fe alloy has good electromagnetic property and could be used in MEMS actuator manufacturing.