JPS58125233A - Magnetic recording body - Google Patents

Abstract

PURPOSE:To obtain a vertical recording magnetic recording body which is excellent in wear resistance, by forming a ferromagnetic thin film by sputtering on the surface of a discoid or cylindrical mild magnetic material, and forming a guide ridge of a vortexlike or spiral nonmagnetic recording and reproducing magnetic stylus on said surface. CONSTITUTION:On the surface of a mild magnetic material disk 1 (or a cylinder) manufactured from soft iron etc., a ferromagnetic thin film 2 consisting of a Co-Cr alloy, a Co-Mo alloy, etc. is formed to uniform thickness (0.1- several mu) by means of sputtering. On the surface of this thin film 2, a guide ridge 3 of a vortexlike (spiral in case of a cylinder) recording and reproducing magnetic stylus consisting of rigid plastic and a nonmagnetic material such as brass, etc. is formed. In this way, it is possible to obtain a magnetic recording disk (or cylinder) of a vertical magnetizing system, which is excellent in wear resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a perpendicularly magnetized magnetic recording disk or drum.

In the perpendicular magnetization recording method, the recording magnetic field is applied in the direction perpendicular to the magnetic film, so the magnetic recording density is high. Magnetization can also be made sufficiently large.

However, although research and development of a magnetic recording medium suitable for such a perpendicular magnetization method has been actively conducted for several years, it has not yet reached a satisfactory level.

The inventor of the present application has previously provided a magnetic recording medium suitable for perpendicular recording in Japanese Patent Application No. 55-22222 (% Opening and Closing No. 56-119954), but the inventor has provided a magnetic recording medium suitable for perpendicular recording, which is fully satisfactory in terms of manufacturing and wear resistance of the magnetic film. It wasn't the book I should have read.

The present invention forms a ferromagnetic film to improve these drawbacks, and forms spiral or helical non-magnetic ridges for guiding magnetic recording and reproducing needles on the surface of the ferromagnetic film. It is in a magnetic recording medium.

An embodiment of the present invention will be described below.

FIG. 1 shows a schematic enlarged cross-sectional view of the magnetic recording disk of the present invention. In the figure, reference numeral 1 denotes a soft magnetic disk made from Soft Iron Co., Ltd. On the surface of the disk 10, a ferromagnetic thin film 2 is formed by sputtering in a uniform filling time of 0.1 seconds to several microns.

E, □2.2, E4f C8-0, ゝW copper alloy Cu-
Al-Mn alloy, Co-Mo-V alloy, etc. are preferred,
Moreover, it is desirable that the crystal axis direction is aligned in the direction of the film thickness. A sputtering technique in which the crystal axis direction is the film thickness direction for these alloys has been proposed (Japanese Unexamined Patent Publication No. 1983
-511504, Japanese Patent Application No. 56-182252, Japanese Patent Application No. 1984-194400, etc.). 3 is a spiral or spiral ridge made of a non-magnetic material (hard plastic, brass, etc.). As an example of a method for forming the ridges S, the ferromagnetic thin film 2
A non-magnetic layer is first formed with a uniform thickness on the 0 surface, and then a spiral groove is cut with a diamond cutter P- to a depth that reaches the ferromagnetic thin film, and the remaining portion is used as a ridge 5. Alternatively, in the case of a non-magnetic metal, it can be made by applying a photomask method and an etching method to form highly accurate grooves in the non-magnetic material layer. In addition, when plastic is used as a nonmagnetic material, a plastic layer of uniform thickness is formed on a ferromagnetic thin film, and then a heated mold having a flat end surface and a spiral groove is pressed onto the plastic layer. Alternatively, a method of scraping off the plastic thin film remaining at the groove bottom of the plastic ivy layer with a diamond cutter or a method of removing it with a solvent can be adopted.

The ridges 3 obtained in this manner constitute a guide for the magnetic needle, and the magnetic needle moves in the groove 1 (spiral/spiral), and the magnetic field is applied vertically to the ferromagnetic thin film. It will be done. Incidentally, a ferromagnetic thin film and guide ridges can also be formed on the back surface of the disk 1 by the same method as described above.

To perform magnetic recording and reproduction using the magnetic recording body of the present invention, the magnetic recording body is rotated around the central axis 40 as shown in FIG. insert. Since the head 6 forms a closed magnetic path via the loaf 7, the slider or roller 8, and the soft magnetic plate 1, recording and reproducing from the ferromagnetic thin film can be performed efficiently.

[Brief explanation of the drawing]

FIG. 11 is a conceptual cross-sectional view of the magnetic recording body of the present invention, and FIG. 2 is a partial cross-sectional view showing the state in which the magnetic recording body of the present invention is used. The main parts in the figure are as follows. 1: Soft magnetic disk 2 Varnish battering ferromagnetic thin film 3: Ribbed ridges

Claims (1)

[Claims] (1) A ferromagnetic thin film is formed with a uniform thickness on the surface of a disc-shaped or cylindrical soft magnetic material by sputtering, and - a spiral or helical non-magnetic recording is made on the surface of the ferromagnetic thin film. Furthermore, a magnetic recording body is characterized in that a ridge for guiding a magnetic needle for reproduction is formed.