公开(公告)号：US20140287269A1

公开(公告)日：2014-09-25

申请号：US14299881

申请日：2014-06-09

Applicant: HOYA CORPORATION

Inventor： Shinji EDA ,  Hideki ISONO ,  Takashi MAEDA ,  Hiroshi TSUCHIYA ,  Yoshinori MARUMO

IPC: G11B5/73

CPC classification number: C03C23/009 ,  C03C19/00 ,  C03C21/008 ,  C03C23/0075 ,  C03C2204/08 ,  C09G1/02 ,  G11B5/7315 ,  G11B5/8404 ,  G11B5/8408

Abstract: Provided are a magnetic disk substrate and a method of manufacturing the same, wherein the magnetic disk substrate has very few defects present on its surface with an arithmetic mean roughness (Ra) at a level in the vicinity of 0.1 nm and thus is suitable as a substrate for a magnetic disk with high recording density. The magnetic disk glass substrate is such that the arithmetic mean roughness (Ra) of the main surface of the glass substrate measured using an atomic force microscope with a resolution of 256×256 pixels in a 2 μm×2 μm square is 0.12 nm or less and the number of defects detected to have a size of 0.1 μm to 0.6 μm in plan view and a depth of 0.5 nm to 2 nm is less than 10 per 24 cm2, wherein the defects are each detected using a shift in wavelength between incident light and reflected light upon irradiating and scanning helium neon laser light with a wavelength of 632 nm on the main surface of the glass substrate.

Abstract translation: 提供一种磁盘基板及其制造方法，其中，磁盘基板的表面上存在极少的缺陷，算术平均粗糙度（Ra）在0.1nm附近，因此适合作为 具有高记录密度的磁盘的基板。 磁盘玻璃基板使用原子力显微镜在2μm×2μm的正方形中以256×256像素的分辨率测量的玻璃基板的主面的算术平均粗糙度（Ra）为0.12nm以下 并且在平面图中检测为具有0.1μm至0.6μm的尺寸和0.5nm至2nm的深度的缺陷的数量小于每24cm 2的10个，其​​中每个使用入射光之间的波长偏移检测缺陷 并在玻璃基板的主表面上照射和扫描波长为632nm的氦氖激光的反射光。