JPS63251935A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To obtain good C/N at the time of high-density recording and reproducing by sputtering vapor deposition under magnetron discharge at a higher speed by providing spherical ruggedness to a target at the time of forming a thin ferromagnetic metallic film by magnetron sputtering vapor deposition. CONSTITUTION:The target 14 is formed of an alloy target 14-1 disposed with spherical projections on the surface or 14-2 constituted by coating and fixing particles 20 to a nonmagnetic sheet 19 and disposing a ferromagnetic alloy layer 21 thereon. More specifically, the target 14 having the spherical ruggedness is used at the time of forming the above-mentioned film by magnetron sputtering vapor deposition on the moving substrate 10. The intensity of leakage magnetic fluxes is thereby modulated and the thin ferromagnetic metallic film formed by the sputtering vapor deposition is constituted of the finer columnar particles. Noises are suppressed and the good C/N is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method of manufacturing a magnetic recording medium using a ferromagnetic metal thin film as a magnetic recording layer.

Conventional technology In recent years, there has been remarkable progress in increasing the density of magnetic recording.
It has become necessary to develop new technology for the combination of magnetic heads and magnetic recording media. That is, as the recording unit becomes smaller, the amount of magnetic flux decreases, so it is essential to use materials with high magnetic flux density in order to maintain a practical level of C/N for magnetic flux differential type recording and reproduction. ing〔
Japanese Patent Publication No. 58-91, Japanese Unexamined Patent Publication No. 139919/1982]. Such magnetic recording media are produced by electron beam evaporation onto polymer films such as polyester films and polyimide films while being cooled with a rotating support.

It is obtained by forming a ferromagnetic metal thin film using ion blating method, sputtering method, etc.
Japanese Patent Publication No. 61-47221, Japanese Patent Publication No. 57-2104
No. 52, JP-A-60-59534, JP-A-Sho 6
1-240437].

Among magnetic recording media, the electron beam evaporation method is mainly being considered for manufacturing magnetic tapes, and the sputtering method is mainly being considered for manufacturing magnetic disks. Furthermore, as a sputtering method, applications such as RF magnetron discharge, DC magnetron discharge, and facing target type are being considered [for example, Japanese Patent Application Laid-Open No. 61-2536
36-263638].

FIG. 2 is a block diagram of the main parts of a magnetic recording medium manufacturing apparatus to which the sputtering method is applied. In Figure 2, 1 is a polymer film, 2 is a rotating support, 3 is an unwinding shaft, 4 is a winding shaft, 5 is a ferromagnetic alloy target, 6 is a magnetic field generator, 7 is a vacuum chamber, and 8 is a vacuum Tank 9 is a free roller. Although there are ways to increase the amount of magnetic flux leakage by making cuts in the target, the magnetic properties are often controlled mainly by the temperature of the polymer film, and in order to stably obtain long lengths, glow discharge is The power was set low.

Problems to be Solved by the Invention However, with the above configuration, it is necessary to increase the speed by arranging a plurality of targets in the direction of movement of the substrate. /
Since Ni cannot be secured, improvement was desired.

The present invention was made in view of the above-mentioned circumstances, and has a good C.
The present invention provides a method for manufacturing a magnetic recording medium that can obtain a magnetic recording medium of /N.

Means for Solving the Problems In order to solve the above-mentioned problems, the method for manufacturing a magnetic recording medium of the present invention is such that the target has spherical irregularities during magnetron sputter deposition on a moving substrate. be.

According to the present invention, with the above-described configuration, the intensity of the leakage magnetic flux is modulated, and the columnar particles constituting the sputter-deposited ferromagnetic metal thin film are made finer, so noise is improved and C/N is improved. can be obtained, and since the electron trapping effect is strengthened by the action of the magnetic field, the power of the glow discharge can be increased, and the speed can also be increased.

EXAMPLE Hereinafter, an example of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram of main parts of a sputter deposition apparatus used for carrying out the present invention.

In Figure 1, 10 is polyethylene terephthalate, polyethylene naphthalate, polyphenylene sulfide,
A polymer film such as polyamideimide or polyimide or a substrate such as a Mu1 alloy substrate, 11 is a rotating support, 12.
13 is a feeding shaft and a winding shaft, respectively, and the board is A/
In the case of a rigid disk such as an alloy plate, a separate transport system is used. 14 is Go-Or
, Go-Ti.

Co-Ni, Co-Pt, Go-Rut Co-N
An alloy target 14 made of i-Nb or the like, whose cross section has spherical protrusions on its surface, as shown in FIG. 1(b).
-1 or Figure 1 (as the cross section is schematically shown in C1,
A structure 14-2 in which particles 20 are coated and fixed on a non-magnetic thin plate 19, and an alloy ferromagnetic layer 21 serving as a target is arranged thereon by plating, vapor deposition, sputtering, etc.
etc. may be configured as appropriate. 15 is a magnetic field generator, 16 is a vacuum chamber, 17 is a vacuum exhaust system, and 18 is a free roller.

In the apparatus shown in FIG. 1 (IL), the diameter of the rotating support is 6
ocIn, and the distance between the target surface and the rotating support is 6.
crIL, and the target conditions and magnetic field generator were selected so that the magnetic field generated by the magnetic field generator was at least 5006 mm at the target surface. The target was made by making many spherical depressions on the surface of the water-cooled copper hearth when the melted Co-Cr (Or20wt%) was hardened using the water-cooled copper hearth.The target was a 2ff thick stainless steel plate. A 1MM Mu e203 ball is fixed on top with polyimide resin, and Go-Or (Or: 20wt chi) is placed on top of it.
Target B was prepared by forming 1 mt by ion blating. In both cases, the density of spherical protrusions was 26/c4. The size of the target was 13 cIrL in the longitudinal direction and 22 cIrL in the width direction. For comparison, a comparison was made with sputter deposition using a Co-0r (Cr: 20 wt%) flat plate target with a thickness of 10 mm.

While moving a polyethylene terephthalate film with a thickness of 11 μm along a rotating support maintained at 20°C,
Using target person, Ar: 5.3X10' Tor
Co-cry was sputter-deposited with a glow discharge of 13.56 MH21, 23 kW at r, and 0.15 μm of co-cry was formed using tape A (slit to a width of a millimeter), target Bi, and temperature r: 4 × 10 Torr. l
A 0.15 μm thick Go-Cr film was formed by sputter deposition using a glow discharge of 13.56 MHz and 1.66 kW, and a tape B was obtained.

A comparative example is Murnia, 6X10'Torr 13.
Tape C was manufactured by sputtering deposition using glow discharge at 56 MHz, o, and 75 kW to form a Go=Or film with a thickness of 15 μm. Three types of tape are available on the market.
Modified millivideo (VX-801, made by Kishita Denki), ferrite head with gap length of 0.13 μm, 0.4 μm
When recording and reproducing a rectangular wave with a wavelength of

Tape B was good with +3.5 dB and +4.9 dB, respectively.

It goes without saying that the embodiment is not limited to a tape, but may also be a disk, and there is no particular restriction on the direction of magnetization in the nine in-plane directions in the vertical direction.

Effects of the Invention As described above, according to the present invention, sputter deposition using high-speed magnetron discharge provides good C during high-density recording and reproduction.
/N'ii can be manufactured.

[Brief explanation of drawings]

FIG. 1 (IL) is a configuration diagram of the main parts of the sputter deposition apparatus used in the implementation of the present invention, FIGS. 1(b) and (C) are cross-sectional views showing the target, and FIG. FIG. 10...Substrate (polymer film), 14...
...Target with spherical protrusions. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure IO - Polymer film lift 4 - Target (with spherical projections) <b) Figure 2

Claims (1)

[Claims] 1. A method for manufacturing a magnetic recording medium, characterized in that a target has spherical irregularities when depositing a ferromagnetic metal thin film on a moving substrate by magnetron sputtering.