Glass substrate for magnetic disc, method for manufacturing such glass substrate, magnetic disc and method for manufacturing such magnetic disc

A technology for glass substrates and manufacturing methods, which is applied in the direction of manufacturing base layers, disc carrier manufacturing, magnetic recording layers, etc., can solve problems such as cumbersomeness and damage to the main surface, achieve easy grinding, large objects to be ground, and reduce costs Effect

Inactive Publication Date: 2008-03-19
HOYA CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, it is very cumbersome to stack and hold many miniaturized glass substrates for magnetic disks, and at the same time, when stacking and holding many glass substrates for magnetic disks, there is a possibility of damage to the main surfaces of these glass substrates for magnetic disks. Improve workability and product productivity

Method used

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  • Glass substrate for magnetic disc, method for manufacturing such glass substrate, magnetic disc and method for manufacturing such magnetic disc
  • Glass substrate for magnetic disc, method for manufacturing such glass substrate, magnetic disc and method for manufacturing such magnetic disc
  • Glass substrate for magnetic disc, method for manufacturing such glass substrate, magnetic disc and method for manufacturing such magnetic disc

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0113] In this Example 1, the glass substrate for magnetic discs was manufactured through the following process.

[0114] (1) The process of obtaining a cylindrical glass base material

[0115] In this example, a glass base material made of aluminosilicate glass was prepared.

[0116] The size of the glass base material was 28.6 mm in diameter.

[0117] (2) The process of forming a center hole in the glass base material

[0118] Next, a center hole is formed along the center axis of the glass base material 3 . The inner diameter of the central hole is 5.9 mm.

[0119] (3) The process of grinding (mirror finishing) the side surfaces of the inner and outer peripheries of the glass base material

[0120] The outer peripheral side (peripheral surface) of the glass base material was mirror-polished by a polishing brush polishing method. At this time, as the abrasive grains, a slurry (free abrasive grains) containing cerium oxide abrasive grains is used.

[0121] Next, the inn...

Embodiment 2

[0165] In this Example 2, a magnetic disk was manufactured by the following process using the glass substrate for magnetic disks produced in said Example 1.

[0166] On the two main surfaces of the above-mentioned glass substrate for magnetic disks, a Ni-Ta alloy first base layer, a Ru second base layer, Co-Cr-Pt-B Alloy magnetic layer, hydrogenated carbon protective layer. Next, an ethylene-modified polytetrafluoroethylene-based lubricating layer was formed by a dipping method. In this way, a magnetic disk for perpendicular magnetic recording was obtained.

[0167] In the obtained magnetic disk, it was confirmed that no defects due to foreign matter occurred on films such as the magnetic layer. In addition, no collision (collision between the head and the protrusions on the surface of the magnetic disk) and damage (collision between the head and the protrusions on the surface of the magnetic disk) were found during the sliding test. Furthermore, in the playback test using ...

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Abstract

A method for manufacturing a glass substrate for magnetic disc includes a step of manufacturing a glass disc by cutting a columnar glass base material (3) vertical to the center axis of the glass base material (3). In the method, a side plane of the glass base material (3) is polished or mirror-polished, chemical reinforcing treatment is performed to the side plane of the glass base material (3), and then the glass base material is cut.

Description

technical field [0001] This invention relates to the glass substrate for magnetic discs used for the magnetic disc which is a recording medium in information recording apparatuses, such as a hard disk drive (HDD), and its manufacturing method. [0002] Moreover, this invention relates to the magnetic disk which is a recording medium in information recording apparatuses, such as a hard disk drive (HDD), and its manufacturing method. Background technique [0003] In recent years, various information processing devices have been proposed with the advancement of the information society, and hard disk drives (HDDs) have been proposed as information recording devices used in these information processing devices. In this hard disk drive, in order to reduce the size and performance of the information processing device, it is required to increase the information recording capacity and increase the recording density, and at the same time to reduce the manufacturing cost. [0004] In ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G11B5/84C03C21/00G11B5/73
CPCG11B5/8404
Inventor 矶野英树
Owner HOYA CORP
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