| 摘要 |
PROBLEM TO BE SOLVED: To provide a manufacturing method of a magnetic disk substrate that can reduce a long period defect of a substrate surface after roughly polished without greatly losing a polishing velocity in a rough polishing in the rough polishing with a non-spherical silica particle as a polishing particle in one embodiment or more.SOLUTION: In one or more embodiments, a manufacturing method of a magnetic disk substrate includes a following step (1). The step (1) is configured to: supply a polishing liquid composition containing a non-spherical particle A, an acid, an oxidizing agent and water to a polishing object surface of a polished substrate; bring a polishing pad to contact with the polishing object surface; and move at least one of the polishing pad and the polished substrate to polish the polishing object surface, where the non-spherical silica particle A has a shape having a plurality of particles aggregated or fused, the polished substrate is a Ni-P plating aluminum alloy substrate, the polishing pad is a polishing pad of a suede type including a base layer and a foaming surface layer in which compressibility of the surface layer is equal to or more than 2.5%. |
