发明名称 |
Substrate for magnetic recording medium, magnetic recording medium, method of manufacturing magnetic recording medium, and method of inspecting surface |
摘要 |
A substrate for a magnetic recording medium having a disc shape with a central hole is provided in which the surface roughness of the principal surface of the substrate is 1 angstrom or less in terms of root mean square roughness (Rq) when a space period (L) of an undulation in the circumferential direction is in the range 10 to 1,000 μm, and in which when a component in the vertical axis direction of a line segment Z connecting a point A with the space period (L) of 10 μm and a point B with the space period (L) of 1,000 μm in a curve S marked on a double logarithmic graph which is obtained by analyzing the surface roughness using a spectrum and in which the horizontal axis is set to the space period (L) (μm) and the vertical axis is set to the power spectrum density (PSD) (k·angstrom2·μm) (where k is a constant) is defined as H and a displacement at which the component in the vertical axis direction of the curve S is the maximum with respect to the line segment Z is defined as ΔH, a value (P) expressed by (ΔH/H)×100 (%) is 15% or less. |
申请公布号 |
US8951652(B2) |
申请公布日期 |
2015.02.10 |
申请号 |
US201213687446 |
申请日期 |
2012.11.28 |
申请人 |
Showa Denko K.K. |
发明人 |
Yukimatsu Koji;Matsumura Yukihisa;Sueoka Yoshihito;Kishimoto Junichi |
分类号 |
G11B5/73;G11B23/00;G01B7/28;G06F15/00;G01B11/30;G11B5/84 |
主分类号 |
G11B5/73 |
代理机构 |
Sughrue Mion, PLLC |
代理人 |
Sughrue Mion, PLLC |
主权项 |
1. A substrate for a magnetic recording medium having a disc shape with a central hole and having at least a magnetic layer on the surface of the substrate,
wherein the substrate has a principal surface and a surface roughness of the principal surface of the substrate is 1 angstrom or less in terms of root mean square roughness (Rq) when a space period (L) of an undulation in a circumferential direction is in the range 10 to 1,000 μm, and wherein when a component in a vertical axis direction of a line segment Z connecting a point A with the space period (L) of 10 μm and a point B with the space period (L) of 1,000 μm in a curve S marked on a double logarithmic graph which is obtained by analyzing the surface roughness using a spectrum and in which a horizontal axis is set to the space period (L) (μm) and the vertical axis is set to a power spectrum density (PSD) (k·angstrom2·μm) (where k is a constant) is defined as H and a displacement at which the component in the vertical axis direction of the curve S is at a maximum with respect to the line segment Z is defined as ΔH, a value (P) expressed by (ΔH/H)×100(%) is 15% or less. |
地址 |
Tokyo JP |