Patent ID: 6977030

Claim:
The method of manufacture of magnetic disks and other planar magnetic memory devices which include a metal substrate which carries a magnetic film deposited on the surface of an electroless plated nickel alloy layer, the improvement comprising the steps of providing a metal substrate having a cold worked surface, characterized by microstructural mechanical variations at and below the surface resulting from smoothing processes and with an average surface roughness of less than about 30 Angstroms, and vacuum-sputter deposition of a metallic layer onto the surface of the substrate, said metallic layer selected to bind to the substrate, thereby masking said microstructural mechanical variations of the substrate, and to reactively or catalytically nucleate the electroless plating of said nickel alloy in a subsequent wet chemistry step, depositing a nickel alloy layer by electroless plating on said metallic layer, the nickel alloy layer having surface roughness essentially unchanged from that of the cold worked surface of the metal substrate upon completion of the electroless plating, preparing the nickel alloy layer if necessary for formation of a magnetic layer thereon, and depositing a magnetic layer over the nickel alloy layer.