Electrical Resistivity and Solder-Reaction Characteristics of Ni Films Fabricated by Electroplating
Characteristics of electroplated Ni films such as grain size, resistivity, solder wetting angle, and growth rate of intermetallic compound were evaluated as a function of electroplating current density. With increasing the electroplating current density from to , the nodule size on the Ni film surface decreased, grain refinement occurred, and resistivity increased from to . Compared with Ni film processed at , Ni films electroplated at and exhibited low resistivity, dense microstructure, and slow growth rate of intermetallic compound. Ni films electroplated at and are more suitable for Ni UBM application than that fabricated at .