Patent ID: 6123603
Filing Date: 2000-09-26
Classification: G11B,Y10T

Abstract:
A process for manufacturing a magnetic hard disc substrate comprising the steps of:plating a Ni--P coating on a substrate;polishing the Ni--P plated substrate with a polishing solution containing metal oxide abrasive grains to form a surface on said plated substrate having a surface roughness R.sub.a of no more than 15 angstroms and a surface roughness R.sub.max of no more than 200 angstroms; and thenpolishing the Ni--P plated substrate with a colloidal abrasive agent containing at least 0.01% of hydrogen peroxide and silica particles having a grain size not larger than 0.5 .mu.m, said hydrogen peroxide preventing gelation and accelerating the rate of polishing.