Substrate for magnetic disk

Abstract From the Canadian patent

A substrate for a magnetic disk having minute semi-spherical raised portions formed over the entire surface by a non-electrolytic plating process, an electrolytic plating process or plating nuclei containing palladium, gold, silver or, copper. The substrate is obtained by comprising steps of forming a Ni-P intermediate layer by Ni-P plating on an aluminum substrate, finishing the Ni-P intermediate layer, dipping the substrate in a plating solution to effect palladium plating to form a Pd plating layer and forming a Ni-P plating layer to form minute semi-spherical raised portions over an entire surface of the Pd plating layer.