JPS6059533A - Method for arranging magnetic pole in magnetic disc medium manufacturing device - Google Patents

Abstract

PURPOSE:To form a magnetic field having magnetic field distribution vertical to a magnetic disc substrate and uniform in the radius direction by forming a rectangular magnetic pole in the radius direction of the magnetic disc substrate and arranging other magnetic poles on both the sides of the substrate and on the same surface of the substrate. CONSTITUTION:When a coat with uniform thickness is to be formed by applying paint containing magnetic powder to the surface of the magnetic disc substrate 2 and rotating the substrate 2 around a rotary shaft 8, an electromagnet 3 is moved in proximity to the disc substrate 2 and another magnetic pole 1 or 4 is moved in proximity to the electromagnet 3 or another pole 5 is moved in proximity to the opposite position. Or, other poles 1 and 4 are simultaneously moved in proximity to the electromagnet 3 or other poles 1, 4, 5 are simultaneously moved in proximity to the electromagnet 3. It may be available to bring other poles 1, 5 to 4, 5 close to the electromagnet 3. Said arrangement of the magnetic poles makes it possible to form a magnetic field having magnetic field distribution vertical to the disc substrate 2 and uniform in the radius direction.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to an apparatus for manufacturing magnetic disk media, and in particular to a device for manufacturing a magnetic disk medium, in particular a method for coating a magnetic disk substrate with a magnetic paint using a spin code method or immediately after coating. The present invention relates to a method of arranging magnetic poles in a magnetic disk medium manufacturing apparatus for forming a magnetic field applied to a magnetic disk substrate in a so-called swing-off process in which the magnetic disk substrate is rotated at high speed in order to obtain a magnetic disk substrate.

(b) Prior Art and Problems A magnetic disk device is used as a storage device in a computer system, and the storage medium of the magnetic disk device is a magnetic disk. Magnetic disks are made by applying paint containing magnetic powder to a super-finished aluminum base using the spin code method, rotating the base in a magnetic field to dry the paint, and polishing the surface to make it smooth. ing. As the magnetic powder, γ-Fe2O3 is generally used.

In recent years, there has been a strong demand to improve the recording density of information on magnetic disk media. In order to improve the recording density, it is necessary to reduce the thickness of the paint, but as the thickness of the paint becomes thinner, defects such as pinholes and areas with extremely little magnetic powder tend to occur. It is known that it is possible to obtain a uniform coating film by applying a magnetic field during coating, or by applying a magnetic field during the shaking-off process immediately after coating. However, in order to obtain a uniform coating, it is necessary that the magnetic field has a uniform magnetic field distribution in the radial direction in a direction perpendicular to the magnetic disk substrate. For example, if there is a leakage magnetic field in the radial direction of the magnetic disk base, the paint will be unevenly distributed due to the leakage magnetic field, causing unevenness in the thickness of the paint film.

Conventionally, it has been difficult to obtain a magnetic disk medium manufacturing apparatus that forms a magnetic field having a uniform magnetic field distribution in the radial direction in a direction perpendicular to the magnetic disk substrate using a simple method.

(C) Object of the Invention The object of the present invention is to eliminate the above-mentioned drawbacks by using a magnetic pole of a magnetic disk medium manufacturing apparatus that forms a magnetic field with a radially uniform magnetic field distribution in a direction perpendicular to a magnetic disk substrate by a simple method. The purpose is to provide a placement method.

(d) Structure of the Invention The structure of the present invention is directed to a magnetic disk medium manufacturing apparatus that applies a paint containing magnetic powder to a magnetic disk substrate by the Svinco-1 method and rotates at high speed to form a coating film with a uniform thickness. At the time of forming the coating film on the magnetic disk substrate, a rectangular magnetic pole is provided in the radial direction of the magnetic disk substrate in the vicinity of the magnetic disk substrate and has a width greater than the width of the coating on the magnetic disk substrate, and the magnetic disk disposing the other pole at a position opposite to the magnetic pole across the base, and/or at a position close to the magnetic pole on the same surface of the magnetic pole and the magnetic disk base, and/or at both positions close to the magnetic pole; The space is parallel to the radial direction of the magnetic disk base and is equally spaced, and when a permanent magnet is used for the rectangular magnetic pole, there is a high conductivity on the surface of the permanent magnet facing the magnetic disk base surface. A magnetic path made of a magnetic material is provided, and the other pole and the air gap are formed through the magnetic path.

(6) Examples of the invention Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an example of a method for arranging magnetic poles in a magnetic disk medium manufacturing apparatus using electromagnets. Figure fa) is a configuration diagram seen from the top, and figure fa) is a sectional view at the position indicated by C in figure al.The magnetic disk base 2 is attached to the rotating shaft 8 and rotates. Magnetic disk base 2
The electromagnet 3 is brought close to the magnetic disk base 2 when the surface of the base 2 is diffused or during the shaking-off process, and the other pole 1 is brought close to the electromagnet 3 as shown in FIG. Or bring the other poles 4 closer together. Alternatively, the other pole 5 is brought close to the opposing position. Or, bring the other poles 1 and 4 close to each other at the same time. Or, bring the other poles 1, 4, and 5 close to each other at the same time. Alternatively, the other poles 1 and 5 or 4 and 5 may be brought close to each other at the same time. In this case, the other pole is made of high-permeability pure iron, permalloy, etc., and the magnetic path 6
and 7, or other magnets may be used. The structure of the other pole is as shown in the same figure (al).
It is necessary to form a gap parallel to the radial direction of the magnetic disk base 2. By arranging the magnetic poles in this manner, it is possible to apply a magnetic field having a uniform magnetic field distribution in the perpendicular direction and the radial direction to the magnetic disk substrate 2.

The leakage magnetic flux in the radial direction that makes the thickness of the coating film non-uniform becomes approximately zero.

FIG. 2 shows an example of a method for arranging magnetic poles in a magnetic disk medium manufacturing apparatus using permanent magnets. The difference from FIG. 1(b) is that a permanent magnet 3'' is used instead of the electromagnet 3, and that a magnetic [? By providing the magnetic path 9, the lines of magnetic force sent out from the entire surface of the permanent magnet 3'' facing the magnetic disk base 2 are concentrated at the corner of the magnetic path shown by 10. Since almost no magnetic flux is sent out from the magnetic flux, it is effective in preventing the generation of leakage magnetic flux.

(f) Effects of the Invention As explained above, the present invention provides a magnetic coating perpendicular to the magnetic disk substrate, which is necessary for forming a thin and uniform coating film of magnetic paint on the magnetic disk substrate when manufacturing a magnetic disk medium. Since it is possible to form a magnetic field that is uniformly distributed in the radial direction and has no leakage magnetic flux, the effect is great.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an example of a method for arranging magnetic poles in a magnetic disk medium manufacturing apparatus using electromagnets, and FIG. 2 is a diagram illustrating an example of a method for arranging magnetic poles in a magnetic disk medium manufacturing apparatus using permanent magnets. It is. 1, 4. 5 is another pole, 2 is a magnetic disk base, 3 is an electromagnet, 3' is a permanent magnet, 6, 7.9 is a magnetic path, and 8 is a rotating shaft. Zerobu (b) 3 1 shi) J'3

Claims (1)

[Scope of Claims] 1) A magnetic disk medium manufacturing apparatus in which a paint containing magnetic powder is applied to a magnetic disk substrate by a spin code method, and the magnetic disk is rotated at high speed to form a coating film with a uniform thickness. Providing a rectangular magnetic pole in the radial direction of the magnetic disk base close to the magnetic disk base when forming the coating film on the base, and having a width larger than the range covering the coating width of the magnetic disk base;
The other pole is arranged at a position opposite to the magnetic pole across the magnetic disk base, and/or at a position close to the magnetic pole on the same surface of the magnetic pole and the magnetic disk base, and/or at both of the close positions. A method for arranging magnetic poles in a magnetic disk medium molding device, characterized in that gaps are formed parallel to the radial direction of a magnetic disk substrate and equally spaced. 2) When a permanent magnet is used for the rectangular magnetic pole, a magnetic path made of a high magnetic conductivity material is provided on the surface of the permanent magnet facing the magnetic disk base surface, and the air gap is formed with the other pole via the magnetic path. A method for arranging magnetic poles in a magnetic disk medium manufacturing apparatus, characterized in that: