公开(公告)号：US09012047B2

公开(公告)日：2015-04-21

申请号：US14246742

申请日：2014-04-07

Applicant: Hoya Corporation

Inventor： Kouji Kitsunai ,  Hiroshi Takeda ,  Yukari Senda

IPC: G11B5/73 ,  C03C3/083 ,  G11B5/82 ,  G11B20/18

CPC classification number: G11B5/7315 ,  C03C3/083 ,  G11B5/82 ,  G11B20/1816 ,  G11B2220/2516 ,  Y10T428/21

Abstract: The shape and number of surface defects are controlled so that the occurrence of failure is suppressed in an HDD device in which a magnetic head with a very small flying height, such as a DFH head, is mounted.A magnetic disk substrate is characterized in that when laser light with a wavelength of 405 nm and a laser power of 25 mW is irradiated with a spot size of 5 μm and scattered light from the substrate is detected, the number of defects detected to have a size of 0.1 μm to not more than 0.3 μm is less than 50 per 24 cm2 and, with respect to the defects, there is no defect in which, in a bearing curve obtained by a bearing curve plot method using an atomic force microscope, a portion from an apex of the defect to 45% thereof is located in an area of defect height higher than a virtual line connecting from the apex of the defect to 45% thereof.

Abstract translation: 控制表面缺陷的形状和数量，使得在安装有诸如DFH头的飞行高度非常小的磁头的HDD装置中，可以抑制故障的发生。 磁盘基板的特征在于，当以5μm的点尺寸照射波长为405nm，激光功率为25mW的激光，并检测到来自基板的散射光时，检测出具有 0.1μm〜0.3μm的尺寸小于每24cm 2的50个，对于缺陷，没有缺陷，在通过使用原子力显微镜的轴承曲线绘图法得到的轴承曲线中， 从缺陷的顶点到其45％的部分位于高于从缺陷的顶点连接到其缺陷的虚拟线的缺陷高度的45％的区域中。

公开(公告)号：US20140220386A1

公开(公告)日：2014-08-07

申请号：US14246742

申请日：2014-04-07

Applicant: HOYA CORPORATION

Inventor： Kouji KITSUNAI ,  Hiroshi Takeda ,  Yukari Senda

IPC: G11B5/73 ,  C03C3/083 ,  G11B5/82

CPC classification number: G11B5/7315 ,  C03C3/083 ,  G11B5/82 ,  G11B20/1816 ,  G11B2220/2516 ,  Y10T428/21

Abstract: The shape and number of surface defects are controlled so that the occurrence of failure is suppressed in an HDD device in which a magnetic head with a very small flying height, such as a DFH head, is mounted.A magnetic disk substrate is characterized in that when laser light with a wavelength of 405 nm and a laser power of 25 mW is irradiated with a spot size of 5 μm and scattered light from the substrate is detected, the number of defects detected to have a size of 0.1 μm to not more than 0.3 μm is less than 50 per 24 cm2 and, with respect to the defects, there is no defect in which, in a bearing curve obtained by a bearing curve plot method using an atomic force microscope, a portion from an apex of the defect to 45% thereof is located in an area of defect height higher than a virtual line connecting from the apex of the defect to 45% thereof.

Abstract translation: 控制表面缺陷的形状和数量，使得在安装有诸如DFH头的飞行高度非常小的磁头的HDD装置中，可以抑制故障的发生。 磁盘基板的特征在于，当以5μm的点尺寸照射波长为405nm，激光功率为25mW的激光，并检测到来自基板的散射光时，检测出具有 0.1μm〜0.3μm的尺寸小于每24cm 2的50个，对于缺陷，没有缺陷，在通过使用原子力显微镜的轴承曲线绘图法得到的轴承曲线中， 从缺陷的顶点到其45％的部分位于高于从缺陷的顶点连接到其缺陷的虚拟线的缺陷高度的45％的区域中。