JPH0312028A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To prevent local deterioration or long-term secular change variation of magnetic characteristics and to improve reliability of the medium by burnishing the surface of a magnetic thin film and then heat-treating the medium to remove residual strain in the thin film and a substrate. CONSTITUTION:A magnetic film provided on a nonmagnetic supporting body is subjected to burnishing treatment with a tape, etc. Residual strain in the thin film and the supporting body due to burnishing treatment is removed by heat-treating the medium in vacuum or inert atmosphere. Thereby, troubles such as data loss can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to improving the reliability of magnetic recording media, particularly to those in which heat treatment is performed after inning processing.

[Prior Art] As the recording density of magnetic disk devices increases, the amount of spacing between the magnetic head and the medium has a great effect on the recording density. However, with the demand for increased recording density, the flying height of the head is being minimized. ing. For this reason, the surface of the medium needs to be processed with high precision, and some surface smoothing processing is performed.

For example, FIG. 2 is a schematic diagram showing the relationship between a conventional burnishing head for smoothing the surface of a medium and a medium, as disclosed in Japanese Patent Application Laid-open No. 59-1163, and FIG. 3 is a perspective view of the burnishing head. FIG. 4 is an enlarged sectional view showing the cross-sectional shape of the groove of the burnishing head.

In the figure, (1) is a magnetic recording medium, <2) is a burnishing head, (3) is a microprotrusion, and (4> is a groove.The slider surface of the burnishing head (2>) has a convex part as shown in Figure 4. A banning head (2) having a slider surface formed of a groove (4) consisting of a convex part and a concave part (5) and a concave part (6) is levitated above the rotating magnetic recording medium (1). , a method is used in which the medium surface is smoothed by reciprocating seek in the direction of the arrow to remove minute protrusions on the medium surface.

[Problems to be Solved by the Invention] Burnishing, which is a conventional manufacturing method for magnetic recording media, is effective in removing abnormal protrusions and makes it possible to lower the flying height of the head. Fixed disk devices are non-volatile storage devices with a low unit price per bit, but as mentioned above, the areas where residual stress exists are localized due to the stress. Even if the magnetic properties are poor during writing, the stress distribution changes slightly due to thermal expansion of the medium, resulting in deterioration of the magnetic properties and data loss. arise.

The second invention was made to solve the above-mentioned problems, and aims to eliminate residual stress caused by burnishing and obtain a highly reliable magnetic recording medium.

[Means for Solving the Problems] A method for manufacturing a magnetic recording medium according to the present invention includes burnishing the surface of a magnetic thin film, and then using heat treatment to eliminate residual snow stress in the magnetic thin film caused by the burnishing process. It is something.

[Function] The method for producing a magnetic recording medium according to the present invention involves burnishing the surface of a magnetic thin film using a slider or tape, and then heat-treating it in a vacuum or an inert atmosphere. It is possible to eliminate stress caused by residual snow on the magnetic thin film.

[Example code] An embodiment of this invention will be described below.

Figure 1 shows media that were heat-treated under the following conditions after the media surface was burnished, and media that were not heat-treated. FIG. 3 is an explanatory diagram showing the number of degraded bits.

Heat treatment conditions: 250°C in vacuum for 1 hr, then allowed to cool naturally. However, if the medium is C/Cr/Co-Ni/Cr/N1-P/^1 and has not been heat-treated, contact between the head and the disc due to C8S. The accompanying stress concentration causes a large change in the stress field in the area where residual snow stress was generated during the bunning process, and force is applied to the magnetic film, causing magnetization to disappear due to the inverse magnetostriction effect.

On the other hand, in a heat-treated medium, such a phenomenon is not observed, and problems such as data loss can be solved.

In the above embodiments, the heat treatment conditions were in a vacuum, but the same effect can be achieved even in an inert gas that does not react with the medium.

In addition, by introducing the second heat treatment step after other media manufacturing steps that cause residual snow stress in the media, stress relaxation is promoted and further effects can be achieved.

[Effects of the Invention] As described above, according to the present invention, wheat that has been burnished on the surface of the magnetic thin film is heat-treated to eliminate residual snow stress on the magnetic thin film due to the burnishing process. Deterioration of magnetic properties and changes over time can be eliminated, problems such as data loss can be extremely reduced, and highly reliable magnetic recording media can be improved.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing the loss of data or significant decrease in the number of bits in the output level during the C3S test for a medium obtained according to an embodiment of the second invention and a medium not subjected to heat treatment, and FIG. 1 is a schematic diagram showing the relationship between a burnishing head and a medium for smoothing the surface of a conventional magnetic recording medium, FIG. 3 is a perspective view of a burnishing head, and FIG. 4 is an enlarged cross-section showing the cross-sectional shape of the burnishing groove. It is a diagram. In the figure, (1) is the magnetic recording medium, (2) is the burnishing head, (3) is the microprotrusion, <4) is the groove, (5> is the convex part of the groove, and (6) is the concave part of the groove. , the same reference numerals in the figures indicate the same or corresponding parts.

Claims (1)

[Claims] In a method of manufacturing a magnetic recording medium in which a magnetic thin film is provided on a non-magnetic substrate, after the surface of the magnetic thin film is burnished, residual stress in the magnetic thin film due to the burnishing process is eliminated by heat treatment. A method for manufacturing a magnetic recording medium.