JPH06111310A - Vapordeposition device for magnetic recording medium - Google Patents

Abstract

PURPOSE:To continuously form two layers of vapor deposition type magnetic layers varying in the inclination direction of columns and thickness on a nonmagnetic base material. CONSTITUTION:First and second guide bodies 4, 5 are provided above a can 3 by shifting these bodies above and below. The opposite spacing between a first route A of the nonmagnetic base material 8 heading toward the can 3 from the first guide body 4 and a second route B of the nonmagnetic base material 8 heading toward the second guide body 5 from the can 3 is so set as to be narrower on the guide body 4, 5 side than the can 3 side. An evaporating source 9 of a magnetic material is disposed into the space held by the first and second routes A, B.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vapor deposition apparatus used for manufacturing magnetic recording media.

[0002]

2. Description of the Related Art As a magnetic recording medium such as a magnetic tape, a vapor deposition type in which a magnetic material is deposited on a non-magnetic base material in a vacuum to form a magnetic layer is compared to a conventional coating type. Since the magnetic layer does not contain a binder, the density of the magnetic material can be increased, and it is attracting attention as being promising for high-density recording.

FIG. 3 shows a conventional vapor deposition apparatus used for manufacturing a vapor deposition type magnetic recording medium. The vacuum container 21 is evacuated by a vacuum pump 22. Inside the vacuum container 21, there is provided a cylindrical can 23 that rotates with an axis line in the horizontal direction, and a take-up roll 24 and a take-up roll 25 are provided above the can 23. Where the unwind roll
The non-magnetic base material 26 unwound from 24 moves along the lower peripheral surface of the can 23 and is wound up by the winding roll 25.

Below the can 23, a magnetic material evaporation source 27 is provided.
The crucible 28 is provided with a magnetic material 29 such as a Co—Ni alloy, and the magnetic material 29 is heated and evaporated by an electron beam emitted from an electron beam gun (not shown). Then, the vapor flow is regulated by the shield plate 30 toward the can 23, and the magnetic material is deposited on the non-magnetic base material 26 moving along the can 23.

In the case of the apparatus shown in FIG. 3, the oblique deposition shown in FIG.
A magnetic layer 31 having a column structure as shown in FIG. Further, when forming the magnetic layer, the oblique vapor deposition direction is changed and the vapor deposition is performed twice, so that the two magnetic layers 32 having different column inclination directions are formed on the non-magnetic substrate 26 as shown in FIG. It is known that when the 33 is formed to have the same overall film thickness, the column does not become thick, so that the characteristics in the high frequency range are improved and the dependence of the magnetic recording / reproducing characteristics on the medium running direction can be made extremely small. 63-1139
No. 28).

[0006]

However, when the magnetic layer is composed of two layers having different column structures, if the vapor deposition is simply performed twice, the cost is increased due to the increase of the man-hours, and the vapor deposition apparatus ( In particular, two evaporation sources are required and the apparatus becomes large. Therefore, JP-A-53-877
By utilizing the technique disclosed in Japanese Patent Publication No. 06 (FIG. 3), as shown in FIG. It was considered to carry out two-layer vapor deposition continuously at 27.

However, in this case, the central portion having the highest vapor density in the vapor flow from the evaporation source 27 is blocked by the shield plate 33, so that the vapor deposition efficiency is poor. Regarding the two magnetic layers, it is effective to reduce the demagnetization by thickening the lower layer and thinning the upper layer. Therefore, if the column height and angle of each layer are different, It was also desired to be able to do so.

In view of the above situation, the present invention is capable of performing continuous two-layer vapor deposition with one evaporation source and is highly efficient.
Another object of the present invention is to provide a vapor deposition apparatus for a magnetic recording medium, which can change the height of columns of each layer.

[0009]

Therefore, according to the present invention, a non-magnetic base material for a magnetic recording medium is provided in a vacuum container with its axis lined out in a substantially horizontal direction, and the peripheral surface on the lower side thereof is wound. Above the cylindrical can to be hung, a first guide body that guides the non-magnetic base material toward the can and a second guide body that guides the non-magnetic base material from the can are provided from the first guide body. The first path of the non-magnetic base material toward the can and the second path of the non-magnetic base material from the can to the second guide body are arranged so that the facing interval is narrower on the guide body side than on the can side, and The first guide body and the second guide body are arranged vertically offset, while the evaporation source of the magnetic material for forming the magnetic layer is arranged in the space sandwiched by the first and second paths, and magnetic A vapor deposition device for a recording medium is configured.

[0010]

In the above structure, one evaporation source
A magnetic material is deposited on the non-magnetic base material on the first path and the non-magnetic base material on the second path. At this time, since the moving direction of the non-magnetic base material on the first path and the moving direction of the non-magnetic base material on the second path are opposite directions, oblique vapor deposition is performed in different directions, and the tilt direction of the column is changed. Of two different magnetic layers are continuously formed.

Further, since the first guide body and the second guide body are vertically offset from each other, the vapor deposition range in the first route and the vapor deposition range in the second route are different from each other. Specifically, if the first guide body is arranged on the upper side,
The vapor deposition range in the first path is longer, and the lower layer formed first of the two layers is thicker. Furthermore, since the inclination angle of the first path and the inclination angle of the second path are different, the degree of inclination of the column of each layer also changes.

Further, by surrounding the upper part of the evaporation source with the first and second paths, the escape of the magnetic material from the evaporation source can be minimized, and the evaporation efficiency is improved.

[0013]

Embodiments of the present invention will be described below with reference to FIGS. With reference to FIG. 1, the vacuum container 1 is evacuated by a vacuum pump 2. Inside the vacuum container 1, there is provided a cylindrical can 3 that rotates with an axis line in the horizontal direction. In addition, cooling water circulates inside the can 3.

Above the can 3, first and second guide members 4 and 5 are provided. Here, the first guide body 4 and the second guide body 5 are arranged vertically offset from each other, and the first guide body 4 is arranged above the second guide body 5. These first and second guide bodies 4 and 5 are guide rolls that can rotate together, and are parallel to each other and to the can 3,
It is arranged.

An unwinding roll 6 is provided beside the first guide body 4, and a take-up roll 7 is provided beside the second guide body 5. Here, the first guide body 4
Guides a non-magnetic base material 8 such as a PET (polyethylene terephthalate) film unwound from the unwinding roll 6 toward the can 3, and the second guide body 5 guides the non-magnetic base material 8 from the can 3. Is guided to take up on the take-up roll 7.

A first path A of the non-magnetic base material 8 from the first guide body 4 to the can 3 and a second path A of the non-magnetic base material 8 from the can 3 to the second guide body 5. The first and second guide bodies 4 and 5 are arranged laterally close to each other so that the facing interval with B becomes narrower on the guide bodies 4 and 5 side (upper side) than on the can 3 side (lower side). There is. Specifically, the vertical surfaces including the axis of the can 3 are arranged so that the peripheral surfaces of the first and second guide bodies 4 and 5 are in contact with each other. in this case,
Since the first guide body 4 and the second guide body 5 are vertically offset from each other, the inclination angle of the first route A is θ ₁ and the inclination angle of the second route B is θ _2. , Θ ₁ <θ ₂ .

In a space above the can 3 and sandwiched by the first and second paths A and B, a Cr— crucible 10 made of MgO, a Co—Ni alloy, and Co—C are used as an evaporation source 9 of the magnetic material.
A magnetic material 11 such as an r alloy or a Co-Cr-Ta alloy is put in and provided, and the magnetic material 11 is heated and evaporated by an electron beam emitted from an electron beam gun (not shown). Incidentally, the electron beam gun may be arranged anywhere as long as the electron beam is appropriately deflected and focused by a deflection coil, a focusing coil or the like to irradiate the magnetic material 11.

Next, the operation will be described. After being unwound from the unwinding roll 6, the non-magnetic base material 8 is guided by the first guide body 4 toward the can 3, and is guided by the second guide body 5 from the can 3 to the unwinding roll 7. The first is
In the first route A from the guide body 4 to the can 3, the magnetic material from the evaporation source 9 is attached to the surface of the non-magnetic base material 8 to deposit the first layer, and the can 3 to the second layer. In the second route B toward the guide body 5, the magnetic material from the evaporation source 9 is attached again onto the vapor deposition surface of the first layer of the non-magnetic base material 8 to vapor deposit the second layer.

At this time, the nonmagnetic substrate 8 on the first path A
2 is opposite to the moving direction of the non-magnetic base material 8 on the second path B, the oblique evaporation is performed in different directions even with the single evaporation source 9, as shown in FIG. Then, two magnetic layers 12 and 13 having different column inclination directions are continuously formed on the non-magnetic base material 8. Further, since the first guide body 4 and the second guide body 5 are arranged so as to be vertically shifted, the vapor deposition range in the first route A and the vapor deposition range in the second route B are different from each other. The vapor deposition range on the path A is longer. Therefore, as shown in FIG.
Of the layers, the lower layer 12 formed earlier becomes thicker and the upper layer 13 becomes thinner. This is effective as a demagnetization measure.

Furthermore, since the inclination angle of the first path A and the inclination angle of the second path B are different, the first path A
The non-magnetic base material 8 is vapor-deposited in a more oblique direction, and the non-magnetic base material 8 in the second path B is vapor-deposited in a more right angle direction. Therefore, as shown in FIG.
Among the layers, the lower layer 12 formed first causes the column to lie down, and the upper layer 13 causes the column to stand. Upper layer
It is easier to record shorter wavelengths when the 13 columns are standing, in other words, 8 mmH for image recording.
Brightness signals, such as the i8 method, are easier to record, and the image becomes clearer.

Further, since the upper part of the evaporation source 9 is surrounded by the first and second paths A and B, most of the vapor can be attached to the non-magnetic base material 8 without letting the vapor from the evaporation source 9 escape. Therefore, the vapor deposition efficiency is good. And since the vapor deposition rate can be increased correspondingly, productivity is also improved. In order to prevent heat loss of the non-magnetic base material 8, a cooling plate may be arranged on the back surface side of the non-magnetic base material 8 along the first and second paths A and B.

With the apparatus of this embodiment, as a non-magnetic substrate
Using a 9.8 μm PET film, Co-
Ni alloy (80% -20%) is deposited in a total amount of 1500Å so that the lower layer is 1000Å and the upper layer is 500Å, and perfluoropolyether (for example, manufactured by Montedison Co., Ltd.) is used as a protective layer. The product name "Homblin") was top-coated with 20Å. After that, as a back coat layer on the back surface opposite to the magnetic layer, carbon having a particle size of 20 nm and a particle size of 60 nm mixed in 1: 1 was mixed with vinyl chloride and urethane in 1: 1.
The thickness of the paint that is dispersed in the binder mixed in
It was applied so as to have a thickness of 0.5 μm. After that, slit into 8mm width, incassed into 8mm videotape cassette, and record single frequency signals of 1MHz and 7MHz,
These were reproduced and compared with a commercially available Sony 8mm reference tape (assuming the tape is 0 dB),
The output (dB) and C / N (dB) were measured.

As Comparative Example 1, a general vapor deposition apparatus as shown in FIG. 3 was used to deposit a single layer of Co--Ni alloy (80% -20%) on a 9.8 .mu.m PET film surface at 1500 liters. However, other conditions were the same as those of the example, and the same measurement was performed. Further, as Comparative Example 2, the first guide body 4 and the second guide body 5 are set to the same height in the vapor deposition device shown in FIG.
Co-Ni alloy (80% on 9.8 μm PET film surface
-20%) was vapor-deposited in a total amount of 1500Å such that the lower layer and the upper layer were equal to 750Å, and otherwise the same measurement was performed under the same conditions as in the example.

The results are shown in Table 1.

[0025]

[Table 1]

From these results, particularly in the high range (7 MHz), both the output and the C / N ratio are large, not only in the single layer (Comparative Example 1) but also in the simple two layer (Comparative Example 2). Therefore, it was confirmed that excellent characteristics were obtained, and that the magnetic recording medium having excellent characteristics could be manufactured by the apparatus of this example. In the above-described embodiment, if a small amount of oxygen is introduced from the outside toward the non-magnetic base material 8 during vapor deposition in the first and second paths A and B, each layer of the magnetic layer is oxidized. Has the advantage that the corrosion resistance is improved and the two magnetic layers can be clearly separated.

[0027]

As described above, according to the present invention, two magnetic layers having different column tilt directions can be continuously formed at one time by a single evaporation source, and the vapor deposition efficiency can be improved. Good, the effect that the productivity is significantly improved can be obtained. Moreover, not only the column tilt direction of each layer but also the thickness of each layer and the column tilt degree can be changed, and it is possible to provide a magnetic recording medium that meets the required characteristics. .

[Brief description of drawings]

FIG. 1 is a schematic diagram of a vapor deposition apparatus showing an embodiment of the present invention.

FIG. 2 is a structural diagram of a magnetic layer according to the same example.

FIG. 3 is a schematic diagram showing a conventional example of a vapor deposition device.

FIG. 4 is a structural diagram of a single-layer magnetic layer.

FIG. 5 is a structural diagram of a two-layer magnetic layer.

FIG. 6 is a schematic view showing a conventional example of a vapor deposition apparatus for obtaining a two-layer type magnetic layer.

[Explanation of symbols]

 1 vacuum container 2 vacuum pump 3 can 4 first guide body 5 second guide body 6 unwinding roll 7 winding roll 8 non-magnetic base material 9 evaporation source 10 crucible 11 magnetic material A first path B second Route

Claims (1)

[Claims] 1. A can above and above a cylindrical can which is provided in a vacuum container with an axis line in a substantially horizontal direction and around which a non-magnetic base material for a magnetic recording medium is wound. A first guide body that guides the non-magnetic base material that faces the first guide body and a second guide body that guides the non-magnetic base material from the can are connected to the first guide body of the non-magnetic base material that faces the can from the first guide body. The first guide body and the second guide body are arranged such that the distance between the path and the second path of the non-magnetic substrate from the can to the second guide body is narrower on the guide body side than on the can side. And a vertically displacing position, and an evaporation source of a magnetic material for forming a magnetic layer is arranged in a space sandwiched by the first and second paths.