SUBSTRATE FOR MAGNETIC DISK, METHOD FOR MANUFACTURING THE SAME, AND MAGNETIC DISK USING SUBSTRATE FOR MAGNETIC DISK

To provide a substrate for a magnetic disk having a stable fluttering characteristic, and a method for manufacturing the substrate.SOLUTION: The substrate for a magnetic disk according to the present invention is characterized in that the flatness is 30 μm or less and the difference in the flatness...

Full description

Saved in:
Bibliographic Details
Main Authors IMAGAWA KIMIE, HATAKEYAMA HIDEYUKI, YONEMITSU MAKOTO, KITAWAKI KOTARO, NAKAMURA TADAHIRO, NAKAYAMA MASARU
Format Patent
LanguageEnglish
Japanese
Published 19.09.2019
Subjects
Online AccessGet full text

Cover

Loading…
More Information
Summary:To provide a substrate for a magnetic disk having a stable fluttering characteristic, and a method for manufacturing the substrate.SOLUTION: The substrate for a magnetic disk according to the present invention is characterized in that the flatness is 30 μm or less and the difference in the flatness between before and after heating processing is performed at 190°C for 20 hours is 20 μm or less. The substrate for a magnetic disk can be manufactured by performing heating processing on the substrate for a magnetic disk after polishing at temperatures of 100°C to 250°C within 72 hours after the last polishing step, which is performed at least one time, is performed.SELECTED DRAWING: Figure 1 【課題】安定したフラッタリング特性を有する磁気ディスク用基板とその製造方法を提供する。【解決手段】本発明に係る磁気ディスク用基板は、平坦度が30μm以下であり、190℃×20hの加熱処理をした前後の平坦度の差が20μm以下となることを特徴とする。この磁気ディスク用基板は、少なくとも1回行われる研磨工程の最後の研磨後72h以内に、研磨後の磁気ディスク用基板を100〜250℃で加熱処理することで製造することができる。【選択図】図1
Bibliography:Application Number: JP20180126498