JPH01315028A - Production of magnetic recording medium - Google Patents

Abstract

PURPOSE:To decrease the anisotropic magnetic fields of the magnetic characteristics of a soft magnetic layer and to obtain the two-layered medium having high quality by providing leak magnetic flux sources in such a manner as to negate the intra-surface components of the magnetic fields formed by incidence of the leak magnetic fluxes from adjacent targets to a substrate surface. CONSTITUTION:The leak magnetic flux sources 20, 21 are provided to the side of the substrate 2 opposite to the targets 7, 10 in the production of the two- layered medium 1 having a soft magnetic layer 8 and a recording layer 11 on the substrate 2. The leak magnetic fluxes 12 from the targets 7, 10 enter the substrate 2 in a manner as to be attracted to magnetic flux sources 20, 21 and, therefore, the intra-surface components of the magnetic fields on the substrate 2 are decreased. As a result, the induced magnetic fields 17 by magnets 16 are decreased by a required min. by the induction in the direction of the axis of each magnetization. The influence of the leak magnetic fluxes incident on the substrate surface from the targets is eliminated in this way and the perpendicular two-layered medium having the high quality is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of manufacturing a magnetic recording medium.

[Conventional technology]

With the development of high-density magnetic recording in magnetic recording,
Research and development is progressing on a so-called perpendicular magnetic recording system in which magnetic recording is performed in a direction perpendicular to a magnetic recording surface. What is the medium used for this set of perpendicular magnetic recording blades?

A so-called single-layer medium in which a recording layer such as Co-Cr for perpendicular magnetic recording is formed on a substrate, and a Ni-
There are so-called two-layer media having a soft magnetic layer such as Fe.

Dual-layer media is more actively researched and developed because magnetic interaction occurs between the soft magnetic layer and the head during magnetic recording, resulting in improved recording and reproducing sensitivity and higher reproduction output. is in progress.

In this two-layer medium, since the magnetic interaction between the soft magnetic layer and the head is strong, its magnetic properties greatly influence the magnitude of the reproduction output, CA ratio, and modulation pressure of the medium. Here, the magnetic properties required for the soft magnetic layer in order to realize a high-quality dual-layer medium, such as high reproduction output, high ratio, good reproduction output, and radiation resistance, are as follows. has been done.

(1) Low coercive force (2) High magnetic permeability (3) The easy axis is not oriented in the track running direction of magnetic recording.

Soft magnetic dual layer media with these magnetic properties can be provided by batch equipment with only one target. However, this has not been achieved in devices with two or more targets intended for mass production. Next, I will explain the reason.

FIG. 5 shows a conventional method for manufacturing a two-layer medium for mass production. The production of the two-layer media is carried out using the following procedure.

(2) The substrate 2 is intermittently conveyed from the original roll 3 to the take-up roll 5 via the guide roll 4.

■ The substrate 2 being transported is stopped at the position of the soft magnetic layer forming section 6, and is guided in the easy axis direction by the induced magnetic field 17 by the magnet 16, and the soft magnetic layer 8 is formed by the tar f,)7. .

(2) The substrate 2 on which the soft magnetic layer 8 has been formed is transported again and stops at the recording layer forming section 9, and the recording layer 11 is formed on the soft magnetic layer 8 by the target 10, completing the two-layer medium 1. do.

As shown in FIGS. 6(a) and 6(b), the induced magnetic field 17 for guiding the direction of the easy axis when forming the soft magnetic layer 8 forms a radial magnetic field on the substrate 2. The magnets 16 are arranged like this. As a result, the soft magnetic layer 8
The direction of the easy axis of the magnetic anisotropy is guided in the direction of the induced magnetic field 17, and the direction of the easy axis is prevented from being directed in the direction 15 of the medium.

[Problem to be solved by the invention]

However, as shown in FIG.
A leakage magnetic flux 12 due to the magnets 10 of the recording layer forming section 9 adjacent to the soft magnetic layer forming section 6 is incident on the substrate 2 . As shown here in FIG.

The in-plane component 13 of the magnetic field on the substrate 2 due to this leakage magnetic flux is
It is not radial, but depending on the location, the easy axis is the tiger, evening direction 1
It's like heading towards 5. For this reason, the direction of the easy axis of the soft magnetic layer 8 is to be prevented from facing the track direction of magnetic recording.

The induced magnetic field 17 generated by the magnet 16 and the like needs to be sufficiently larger than the magnetic field generated by the leakage magnetic flux 12.

However, the magnetic properties of the soft magnetic layer formed in such a large magnetic field are as shown by the M-H loops in the easy axis direction 18 and the hard axis direction 19 in FIG.

The magnetic anisotropy field becomes excessive. As a result, the magnetic permeability of the soft magnetic layer in the hard axis direction, that is, the track running direction of the medium decreases, resulting in a disadvantage that the output of the medium decreases.

As mentioned above, in the conventional manufacturing method for mass-producing two-layer media, in order to reduce the influence of the magnetic field due to the leakage magnetic flux incident from the adjacent target when forming the soft magnetic layer, the direction of the easy axis is Since it was necessary to make the induced magnetic field sufficiently large to induce , the anisotropic magnetic field of the soft magnetic layer becomes large. As a result, the magnetic permeability of the medium in the track direction decreases.

As a result, the output of the medium is reduced and the quality cannot be improved.

Therefore, an object of the present invention is to provide a method for manufacturing a high-quality perpendicular two-layer medium by eliminating the influence of leakage magnetic flux incident on the substrate surface from adjacent targets in forming the soft magnetic layer of the two-layer medium. be.

[Means to solve the problem]

The inventors investigated the magnetic anisotropy of the magnetic properties of the soft magnetic layer.
We have found that the direction of the easy axis is induced by the in-plane component of the magnetic field on the substrate, and that in order to reduce the anisotropic magnetic field, it is sufficient to reduce the magnetic field on the substrate.

Therefore, when forming a soft magnetic layer, if the leakage magnetic flux source is installed so that the leakage magnetic flux from an adjacent target etc. enters the substrate surface of the soft magnetic layer and cancels the in-plane component of the magnetic field that is formed, it is possible to easily It is possible to minimize the induction magnetic field applied to the substrate surface of the soft magnetic layer to induce , and it is possible to reduce the anisotropic magnetic field of the magnetic properties of the soft magnetic layer.

In view of the above, the present invention provides a method for forming a magnetic recording medium having a soft magnetic layer using two or more targets, in which adjacent targets flowing into a substrate on which the soft magnetic layer is formed (r)
The magnetic leakage flux source is installed to generate a magnetic field that cancels the in-plane component of the magnetic field generated by the leakage flux from the soft magnetic layer, and the magnetism and masticability of the soft magnetic layer can be controlled.

〔Example〕

FIG. 1 shows an embodiment of the invention. In the present invention as well, the following steps are basically adopted as in the conventional manufacturing method.

(2) The substrate 2 is intermittently conveyed from the original roll 3 to the take-up roll 5 via the guide roll 4.

(2) The substrate 2 being transported is kept stationary at the position of the soft magnetic layer forming section 6, and the soft magnetic layer 8 is formed on the target 7.

An easy axis is induced and formed by an induced magnetic field 17 by a magnet 16.

(2) The substrate 2 on which the soft magnetic layer 8 was formed is transported again.

The target 10 is held stationary at the position of the recording layer forming section 9, and the di-recording layer 11 is formed on the soft magnetic layer 8 using the target 10, thereby completing the production of the two-layer medium 1.

Here, in the present invention, the following configuration is added to the conventional manufacturing method. That is, in the present invention, leakage magnetic flux sources 20 and 21 were installed on the back side of each of the target 7 forming the soft magnetic layer 8 and the targets p, ) io forming the recording layer 11 when viewed from the substrate 2. These leakage magnetic flux sources 20.21 each form a pair of tarf, )7.10
It has the same magnetic structure as , but its magnetic poles N and S are reversed. And the installation position is viewed from board 2.

Each pair of tags was placed in a symmetrical position to 7.10.

According to this, the following effects can be obtained.

When viewed from the board 2, the leakage magnetic flux sources 20.21 are installed symmetrically and on the back side of the turrets 7.10, so that the leakage magnetic flux 12 emitted from each turret 7.10 is the opposite leakage flux source. Let yourself be drawn to 20.21,
The light will be incident on the substrate 2. Therefore, the in-plane component of the magnetic field on the substrate 2 due to this leakage magnetic flux 12 is sufficiently reduced. Therefore, it has become possible to minimize the induction magnetic field 17 applied by the magnet 16 or the like for guidance in the easy axis direction.

As a result, the anisotropic magnetic field became small as shown in the M-H loop of the magnetic properties in the easy axis direction and the hard axis direction of the soft magnetic layer formed as shown in FIG. Furthermore, even though the induced magnetic field was kept to the minimum necessary, the easy axis direction 14 of the soft magnetic layer 8 was also perpendicular to the longitudinal direction 15 over the entire surface, as shown in FIG.

Since the magnetic properties of the soft magnetic layer can be controlled freely in this way, the produced two-layer media has a higher level of control than the conventional one22, as shown in the reproduction output of FIG. 4(,). The playback output, mo-zo, and ration were significantly improved. Furthermore, the medium noise shown in FIG. 4(b) was also lower in the case 23 of the present invention than in the conventional case 22. In other words, it has been revealed that the present invention has the effect of making it possible to produce high-quality two-layer media using mass production equipment.

The present invention is not limited to the one embodiment described above.

The effect of the above-mentioned embodiment is not determined by the configuration or installation position of the leakage magnetic flux source, but rather, when leakage magnetic flux emitted from a target etc. is incident on the substrate surface of the soft magnetic layer, this leakage magnetic flux is formed on the substrate. The V effect occurs because the in-plane component of the magnetic field becomes sufficiently small. Therefore, it is clear that even if the configuration is as described below, it is included in the present invention if it has the same effect.

■ Install the leakage magnetic flux source near the board.

■ Place the leakage magnetic flux source on the target side when viewed from the board.

■ Install leakage magnetic flux sources in areas other than the soft magnetic layer forming area, and do not install them in the soft magnetic layer forming area.

〔Effect of the invention〕

As explained above using the embodiments, according to the present invention,
In forming the soft magnetic layer of a two-layer medium, it becomes possible to provide a high-quality perpendicular two-layer medium by eliminating the influence of leakage magnetic flux incident on the substrate surface from an adjacent target.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram of a manufacturing apparatus showing an embodiment of the present invention, FIG. 2 is an M-H loop diagram showing the magnetic properties of a soft magnetic layer formed according to the present invention, and FIG. 3 is a diagram showing the magnetic properties of a soft magnetic layer formed according to the present invention. Fig. 4 is a plan view showing the distribution of the easy axis direction of the soft magnetic layer produced by the magnetic layer, and Fig. 4 shows the recording/reproducing characteristics of the prepared medium, where (a) shows the playback output, and (b) shows the noise generated by the medium. , Fig. 5 is a schematic configuration diagram of a manufacturing apparatus that implements a conventional method for manufacturing a two-layer medium for mass production, and Fig. 6 is used to guide the easy axis direction when forming a soft magnetic layer. The method is shown in which (a) is a plan view, (b) is a front view, and FIG. FIG. 8 is a plan view showing the magnetic field generated on the substrate, and FIG. 8 is an M-H Rougue diagram showing the magnetic characteristics of the soft magnetic layer formed by the conventional manufacturing method. DESCRIPTION OF SYMBOLS 1... Two-layer medium, 2... Substrate, 3... Raw roll, 4... Guide roll, 5... Winding roll, 6...
・Soft magnetic layer forming part, 7... Target, 8... Soft magnetic layer, 9... Recording layer forming part, 10... Targ, ),
11...Recording layer. 12... Leakage magnetic flux, 13... In-plane component of magnetic field, 14
...Easy axis direction, 15...Track direction, 16...
·magnet. 17... Induced magnetic field, 18... Easy axis direction, 19...
- Difficult axis direction, 20... Leakage magnetic flux source, 21... Leakage magnetic flux source. 22...Conventional medium, 23...Thing of the present invention. Figure 4

Claims (1)

[Claims] 1. In a method of forming a magnetic recording medium having a soft magnetic layer using two or more targets, the in-plane component of the magnetic field generated by leakage magnetic flux from adjacent targets flowing into the substrate forming the soft magnetic layer. A method of manufacturing a magnetic recording medium, characterized in that a leakage magnetic flux source is installed to generate a magnetic field that cancels out the magnetic field, thereby making it possible to control the magnetic anisotropy of a soft magnetic layer.