Glass substrate for a magnetic disk and magnetic disk
    1.
    发明授权
    Glass substrate for a magnetic disk and magnetic disk 有权
    用于磁盘和磁盘的玻璃基板

    公开(公告)号:US09085486B2

    公开(公告)日:2015-07-21

    申请号:US14299881

    申请日:2014-06-09

    申请人: HOYA CORPORATION

    摘要: 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.

    摘要翻译: 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。

    Glass substrate for a magnetic disk, magnetic disk and method of manufacturing a magnetic disk
    4.
    发明授权
    Glass substrate for a magnetic disk, magnetic disk and method of manufacturing a magnetic disk 有权
    磁盘用玻璃基板,磁盘及制造磁盘的方法

    公开(公告)号:US09105293B2

    公开(公告)日:2015-08-11

    申请号:US14094960

    申请日:2013-12-03

    申请人: HOYA CORPORATION

    IPC分类号: G11B5/73 G11B5/82

    CPC分类号: G11B5/7315 G11B5/82

    摘要: A glass substrate for a magnetic disk, wherein, in regions with respect to two places arbitrarily selected on a surface of the glass substrate on its central portion side relative to its outer peripheral end, a surface shape with a shape wavelength in a band of 60 to 500 μm is extracted from surface shapes in each of the regions and, assuming that a root mean square roughness Rq of the surface shape is given as a microwaviness Rq, the difference between the microwavinesses Rq of the regions is 0.02 nm or less or the difference between standard deviations of the microwavinesses Rq of the regions is 0.04 nm or less.

    摘要翻译: 一种磁盘用玻璃基板,其特征在于,在相对于其外周端部的中央部侧的玻璃基板的表面上任意选择的两个位置的区域中,形状波长为60nm的波长的表面形状 在每个区域中从表面形状提取至500μm,并且假设表面形状的均方根粗糙度Rq作为微波特性Rq,则区域的微波特性Rq之差为0.02nm以下,或者 区域的微波的标准偏差之间的差异为0.04nm以下。