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Manufacturing method of glass substrate for magnetic disk and manufacturing method of magnetic disk

A technology of a glass substrate and a manufacturing method, which is applied in the field of magnetic disk manufacturing, can solve the problems of increasing the surface roughness of processing, deepening of the processed metamorphic layer, and reducing processing costs, so as to reduce processing load, improve productivity, and reduce cost effect

Active Publication Date: 2018-06-01
HOYA CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] In the existing free abrasive grains, deformed abrasive grains exist unevenly between the mold base and the glass, so the load on the abrasive grains is unstable. When the load is concentrated, the surface of the mold base becomes distorted by cast iron. Low elasticity, so deep cracks will be generated on the glass, the processed deteriorated layer will become deeper, and the surface roughness of the processed glass will also become larger, so more removal is required in the mirror polishing process of the subsequent process, so it is difficult Cut processing costs

Method used

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  • Manufacturing method of glass substrate for magnetic disk and manufacturing method of magnetic disk
  • Manufacturing method of glass substrate for magnetic disk and manufacturing method of magnetic disk
  • Manufacturing method of glass substrate for magnetic disk and manufacturing method of magnetic disk

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0104] After the following (1) substrate preparation process, (2) shape processing process, (3) end face polishing process, (4) main surface grinding process, (5) main surface polishing process (first polishing process), (6) ) The chemical strengthening step, (7) the main surface polishing step (the second polishing step), and the glass substrate for a magnetic disk of the present example was produced.

[0105] (1) Substrate preparation process

[0106] A large plate glass made of aluminosilicate glass with a thickness of 1 mm manufactured by the float glass production method was prepared and cut into small square pieces using a diamond cutter. Next, using a diamond cutter, it was processed into a disk shape with an outer diameter of 65 mm and a circular hole with an inner diameter of 20 mm in the center. As the aluminum silicate glass, the following chemical strengthening glass was used, expressed in wt%, which contained the following composition:

[0107] 58~66% SiO 2 , 13~19% Al...

Embodiment 2

[0130] On the basis of the grinding process of the above embodiment 1, except that the load (P1) of the first stage (roughening) is set to 130g / cm 2 Otherwise, the grinding process was performed in the same manner as in Example 1. Furthermore, except for the grinding process, it carried out similarly to Example 1, and obtained the glass substrate for magnetic discs.

[0131] Table 1 shows the results of measuring the scratches on the ground surface and the processing speed of the entire grinding process for the glass substrate after the grinding process.

Embodiment 3

[0133] On the basis of the grinding process of Example 1 above, except that the load (P1) of the first stage (roughening) is set to 200g / cm 2 Otherwise, the grinding process was performed in the same manner as in Example 1. Furthermore, except for the grinding process, it carried out similarly to Example 1, and obtained the glass substrate for magnetic discs.

[0134] Table 1 shows the results of measuring the scratches on the ground surface and the processing speed of the entire grinding process for the glass substrate after the grinding process.

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Abstract

The present invention provides a method for manufacturing a glass substrate for a magnetic disk, which can shorten the time when the grinding process cannot be performed in the grinding process using fixed abrasive grains, without reducing the processing speed, and suppress the surface roughness of the processed surface. low, can produce high-quality glass substrates. The present invention includes a grinding process in which a main surface of a glass substrate is ground using a lubricating liquid and a mold base equipped with fixed abrasive grains containing diamond particles on the grinding surface. The glass substrate is a glass substrate whose main surface is a mirror surface. The grinding process has a first stage of roughening the surface of the glass substrate with a load higher than that for grinding, and grinding the surface of the glass substrate with a load lower than that for the first stage. second stage. Use the same device for Phase 1 and Phase 2.

Description

Technical field [0001] The present invention relates to a method for manufacturing a glass substrate for a magnetic disk mounted on a magnetic disk device such as a hard disk drive (HDD), and a method for manufacturing a magnetic disk. Background technique [0002] One of the information recording media mounted on a magnetic disk device such as a hard disk drive (HDD) includes a magnetic disk. A magnetic disk is formed by forming a thin film such as a magnetic layer on a substrate. As such a substrate, an aluminum substrate has been used conventionally. However, recently, in response to the pursuit of higher recording density, the proportion of glass substrates that can further reduce the gap between the magnetic head and the magnetic disk has gradually increased compared to aluminum substrates. In addition, the surface of the glass substrate is polished with high precision in such a way that the flying height of the magnetic head can be minimized, thereby achieving high recordi...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): G11B5/84
CPCG11B5/8404
Inventor 深田顺平吉川博则
Owner HOYA CORP