JPH11273062A - Manufacture of magnetic disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a magnetic disk excellent in quality permitting high density recording by tape-cleaning a protective layer surface with precision and stability. SOLUTION: In this method, a magnetic disk is manufactured in such a way that the magnetic disk is tape-cleaned after a substrate, a magnetic layer, and a protective layer have sequentially been formed. The tape cleaning is to be carried out while varying a rotating speed of a magnetic disk according to the radial positions of the cleaning part so that the cleaning part of the magnetic disk runs at speeds of 4.9-9.1 m/sec.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a magnetic disk for recording information, and more particularly, to removing a very small protrusion of the magnetic disk by high-precision tape cleaning to produce a high-quality magnetic disk with high productivity. It relates to a method of manufacturing.

[0002]

2. Description of the Related Art A hard magnetic disk system for recording information employs a CSS (contact start / stop) system in which a magnetic head floats with the rotation of the magnetic disk during operation and contacts the magnetic disk when the motor stops. I have. According to this method, it is possible to suppress wear caused by high-speed sliding between the magnetic head and the magnetic disk. In recent years, with the increase in the recording density of magnetic disks, the distance between the magnetic head and the magnetic disk during recording and reproduction,
That is, the flying height of the magnetic head is becoming smaller and smaller,
Recently, it has become about 0.1 μm or less.

For this reason, the magnetic disk surface is required to have a high degree of flatness, and even a very small projection may cause a head crash and a recording / reproducing error. Generally, after forming a protective layer on a magnetic disk, work is performed to remove minute protrusions on the surface by tape cleaning.However, high-precision grinding is difficult even by tape cleaning. Also,
Even if the cleaning time is lengthened, there has been a problem that abrasion scratches are generated on the surface of the magnetic disk and insufficient grinding occurs.

[0004]

SUMMARY OF THE INVENTION The present invention provides a method of manufacturing a high quality magnetic disk capable of high-density recording and capable of performing tape cleaning of the protective layer surface with high accuracy and stability. Is what you do.

[0005]

Means for Solving the Problems The present invention pays attention to such a problem, and as a result of diligent studies, it has been found that the effect of tape cleaning depends on the traveling speed of the magnetic disk at the time of cleaning. . That is, according to the present invention, in a method of manufacturing a magnetic disk in which a base layer, a magnetic layer, and a protective layer are sequentially formed on a disk substrate and then tape cleaning is performed, the cleaning portion of the magnetic disk is 4.9 to 9.1 m / sec. It is intended to provide a method of manufacturing a magnetic disk, wherein tape cleaning is performed while changing the rotation speed of the magnetic disk in accordance with the radial position of the cleaning portion so as to run at a speed of seconds.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic disk according to the present invention has a base layer and a magnetic layer sputtered on a textured non-magnetic substrate as shown in FIG. 1, and then a protective layer and a lubricant layer are provided. It is preferred that As the non-magnetic substrate, an aluminum alloy substrate, a glass substrate or a silicon substrate is preferably used, but other metal substrates such as copper and titanium, a ceramic substrate or a resin substrate can also be used. The substrate is usually formed in a disk shape, but may be in another shape, for example, a card shape.

Although an underlayer can be formed directly on the surface of the substrate, a surface layer is usually formed on the surface of the substrate, and the underlayer is formed via the surface layer. As the surface layer, NiP
A nonmagnetic surface layer made of an alloy is suitable, and is usually formed by an electroless plating method or a sputtering method. The thickness of the surface layer typically ranges from about 50 to 2000 Angstroms. The surface of the substrate or the surface layer is subjected to mirror finishing (polishing). As the underlayer,
A metal layer such as chromium or copper is suitable, and is usually formed by a sputtering method. The thickness of the underlayer is usually about 5
0 to 2000 angstroms.

The magnetic layer is usually made of Co—Cr, Co—N
i, Co-Cr-X, Co-Ni-X, Co-WX, etc. It is composed of a thin film of a cobalt-based ferromagnetic alloy. Here, X is Li, Si, P, Ca, Ti,
V, Cr, Ni, As, Y, Zr, Nb, Mo, Ru,
Ag, Sb, Hf, Ta, W, Re, Os, Ir, P
t, Au, La, Ce, Pr, Nd, Pm, Sm, Eu
And one or more elements selected from the group consisting of B and B. The magnetic layer is usually formed by an electroless plating method, an electroplating method, a vapor deposition method or a sputtering method. The thickness of the magnetic layer typically ranges from about 100 to 1000 Angstroms.

In the present invention, as the protective layer, a carbon film, a hydrogenated carbon film, a nitrogenated carbon film, TiC,
carbide film such as iC, nitride film such as SiN and TiN, SiO,
An oxide film of Al ₂ O ₃ or ZrO or the like;
Usually, it is formed by a vapor deposition method, a sputtering method, an ion plating method, a wet method, or the like. As the protective layer, a carbon film, a hydrogenated carbon film and a nitrogenated carbon film are particularly preferable. The thickness of the protective layer typically ranges from about 30 to 700 Angstroms, preferably from about 50 to 500 Angstroms. The magnetic disk on which the protective layer is formed is subjected to tape cleaning using a polishing tape. As a polishing tape, usually, a film made of polyethylene terephthalate, polyamide, or the like has a particle size of 0.3 to 3 μm.
A polishing tape carrying polishing abrasive grains such as alumina particles and SiC particles is used. For example, “AWA8000 FNY” and “AWA8000” manufactured by Nihon Micro Coating Co., Ltd.
8000 NA1-C "can be used.

In the present invention, tape cleaning is performed while the magnetic disk is maintained at a constant rotational speed. The rotation of the magnetic disk at the time of tape cleaning is a speed at which the polishing position by the polishing tape rotates and runs at a speed of 4.9 to 9.1 m / sec. Preferably, 5.
6 to 8.4 m / sec, particularly preferably 6.3 to 7.7 m / sec.
Seconds. When the rotational traveling speed is less than 4.9 m / sec,
It is easy to be under-grinded, wear-prone, and
If it exceeds 9.1 m / sec, insufficient grinding is likely to occur. Although the cause is not clear, it is considered to be caused by the contact state between the magnetic disk and the polishing tape.

The present invention is characterized in that the tape cleaning is performed in a state where the rotational running speed of the tape cleaning portion is within a certain range. Therefore, the rotational speed of the magnetic disk is changed depending on the radial position of the cleaning, and the rotational speed per unit time is increased when grinding the inner peripheral portion of the magnetic disk, and the rotational speed is decreased as approaching the outer peripheral portion. For example, in the tape cleaning of a magnetic disk having an inner radius of 15 mm and an outer radius of 47 mm, when cleaning the inner periphery, 2230 to 5230 are used.
800 rpm, preferably 3570-5350 rpm
When cleaning the outer peripheral portion, 71
0 to 1850 rpm, preferably 1140 to 1710 r
pm.

In the tape cleaning of the present invention,
Blowing air on the cleaning tape to prevent the grinding powder from staying on the magnetic disk is also an effective method. After the tape cleaning process after the formation of the protective layer,
Usually, a lubricant layer is provided on the surface of the protective layer. As the lubricant, for example, a fluorine-based liquid lubricant is used, and is usually formed on the surface of the protective layer by a dip coating method, a spin coating method, a spray coating method, or the like. The thickness of the lubricant layer typically ranges from about 5 to 50 angstroms.

[0013]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which should not be construed as limiting the scope of the invention. Examples and Comparative Examples The surface of an aluminum alloy disk substrate on which Ni-P plating was applied to a thickness of 10 μm by electroless plating was polished, and a general Cr underlayer, Co-Cr was formed on the surface layer of the substrate. A magnetic layer made of a -Ta alloy and a protective film made of a carbonaceous film were sequentially formed by a sputtering method. Next, a tape cleaning step was performed under the conditions shown in Table 1. Thereafter, a fluorine-based liquid lubricant was applied to manufacture a magnetic disk. The results were as shown in Table 1.

[0014]

[Table 1]

[Brief description of the drawings]

FIG. 1 is a flowchart showing a manufacturing process of a magnetic disk.

Claims (3)

[Claims] In a method of manufacturing a magnetic disk, in which a base layer, a magnetic layer, and a protective layer are sequentially formed on a disk substrate and then tape cleaning is performed, a cleaning portion of the magnetic disk has a cleaning speed of 4.9 to 9.1 m / sec. A method for manufacturing a magnetic disk, comprising: performing tape cleaning while changing the rotation speed of a magnetic disk according to a radial position of a cleaning portion so as to run at a speed. 2. The method of manufacturing a magnetic disk according to claim 1, wherein the traveling speed of the cleaning portion of the magnetic disk is 5.6 to 8.4 m / sec. 3. The method according to claim 1, wherein the tape cleaning is performed while blowing air on the cleaning tape.