Invention Grant
- Patent Title: Magnetic disk substrate and production method of magnetic disk
- Patent Title (中): 磁盘基板及磁盘制作方法
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Application No.: US11660911Application Date: 2005-08-26
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Publication No.: US07662493B2Publication Date: 2010-02-16
- Inventor: Hiroyuki Machida , Katsuaki Aida , Kazuyuki Haneda
- Applicant: Hiroyuki Machida , Katsuaki Aida , Kazuyuki Haneda
- Applicant Address: JP Tokyo
- Assignee: Showa Denko K.K.
- Current Assignee: Showa Denko K.K.
- Current Assignee Address: JP Tokyo
- Agency: Sughrue Mion, PLLC
- Priority: JP2004-249096 20040827
- International Application: PCT/JP2005/016053 WO 20050826
- International Announcement: WO2006/022446 WO 20060302
- Main IPC: G11B5/60
- IPC: G11B5/60 ; G11B5/66

Abstract:
The invention provides a magnetic disk glass substrate capable of preventing the occurrence of dust and adhesion of particles to the magnetic disk surface during a magnetic disk production process, a production method and a magnetic disk.A glass substrate for a magnetic disk has a construction in which an outer peripheral edge shape formed around a peripheral edge portion of a main surface has, with another flat portion of the main surface being the reference: an outer peripheral edge portion ski jump value of not greater than 0 μm; an outer peripheral edge portion roll-off value of −0.2 to 0.0 μm; and an outer peripheral edge portion dub-off value of 0 to 120 Å; and the glass substrate has a chamfer surface between the main surface (data surface) and the outer peripheral edge surface (straight surface), and has an R surface having a radius of curvature of 0.013 to 0.080 mm between the data surface and the chamfer surface of the glass substrate.
Public/Granted literature
- US20070269684A1 Magnetic Disk Substrate and Production Method of Magnetic Disk Public/Granted day:2007-11-22
Information query
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