JPH06111308A - Vapor deposition device for magnetic recording medium - Google Patents

Abstract

PURPOSE:To continuously form two layers of vapor deposition type magnetic layers having different column structures on a nonmagnetic base material. CONSTITUTION:First and second guide bodies 4, 5 are provided above a can 3. 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 column structure (inclination direction) is different on the non-magnetic substrate 26 as shown in FIG.
It is known that when the magnetic layers 32 and 33 of the two layers are formed to have the same overall film thickness, the column does not become thicker, 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 extremely reduced. (Japanese Patent Laid-Open No. 63-63
-113928 gazette).

[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. The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a vapor deposition apparatus for a magnetic recording medium, which is capable of performing two-layer vapor deposition continuously by one evaporation source and is efficient.

[0008]

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. While the facing distance between 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 toward the second guide is narrower on the guide side than on the can side, An evaporation source of a magnetic material for forming a magnetic layer is arranged in a space sandwiched by the first and second paths to form an evaporation apparatus for a magnetic recording medium.

Here, a cooling plate for cooling the non-magnetic base material may be arranged on the side opposite to the side where the evaporation source of the magnetic material is located along each of the first and second paths.

[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 is opposite to the moving direction of the non-magnetic base material on the second path, oblique vapor deposition is performed in different directions, and the column structure is different. Two magnetic layers are continuously formed.

Here, if the distance between the first and second guide bodies is made sufficiently small, the escape of the magnetic material from the evaporation source can be minimized, and the vapor deposition efficiency is improved. Also,
By disposing a cooling plate for cooling the non-magnetic base material on the side opposite to the side having the evaporation source of the magnetic material along each of the first and second paths which are the vapor deposition sites, thermal deterioration of the non-magnetic base material is achieved. Can be prevented.

[0012]

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 bodies 4 and 5 are provided. The first and second guide bodies 4 and 5 are guide rolls that can rotate together, and are arranged parallel to each other and parallel to the can 3. 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 the non-magnetic base material 8 such as a PET (polyethylene terephthalate) film unwound from the unwinding roll 6 and the can 3
The second guide body 5 guides the non-magnetic base material 8 from the can 3 to be wound around the winding roll 7. Also,
Opposing distance between the first path A of the non-magnetic base material 8 from the first guide body 4 to the can 3 and the second path B of the non-magnetic base material 8 from the can 3 to the second guide body 5. However, the guide body 4, 5 side (upper side) is narrower than the can 3 side (lower side),
The first and second guide bodies 4 and 5 are arranged close to each other. The space S is about 5 to 10 mm. The inclination angles θ of the first and second paths A and B are 20 to 45 °.

In a space above the can 3 and sandwiched by the first and second paths A and B, a crucible 10 made of MgO, a Co-Ni alloy, and Co-C are used as an evaporation source 9 of a 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). Note that 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. Reference numeral 12 is a shielding plate that prevents downward diffusion of the vapor flow.

Further, cooling plates 13 and 14 for cooling the non-magnetic base material 8 are provided along the first and second paths A and B on the side opposite to the side where the magnetic material evaporation source 9 is located (back side). It is arranged. With reference to FIG. 2, the cooling plates 13 and 14 will be described with reference to FIG. 2. The cooling water inlet 13a is provided on the lower side and the cooling water outlet 13b is provided on the upper side.
By this, the cooling water is made to flow around and the non-magnetic base material 8 at the vapor deposition site is cooled from the back surface side.

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
Is opposite to the moving direction of the non-magnetic base material 8 on the second path B. Therefore, although the evaporation source 9 is a single evaporation source, oblique vapor deposition is performed in different directions. The magnetic layers (see FIG. 5) of layers are successively formed. The distance S between the first and second guide bodies 4 and 5 is 5 to 10 mm.
Can be made small, without letting the vapor from the evaporation source 9 escape,
Since most of them can be attached to the non-magnetic base material 8, vapor deposition efficiency is good. And since the vapor deposition rate can be increased correspondingly, productivity is also improved.

Further, the cooling plates 13 and 14 allow the non-magnetic base material 8 to be formed.
Wrinkles due to heat loss are reduced and stable deposition is possible,
This also improves productivity. Using the apparatus of this example, a 9.8 μm PET film was used as the non-magnetic substrate, and Co—Ni alloy (80% -20%) was vapor-deposited on the surface in a total of 1500 Å, and as a protective layer thereon. A 20Å top coat was made of perfluoropolyether (for example, the product name "Homblin" manufactured by Montedison Co., Ltd.). After that, as a back coat layer on the back surface opposite to the magnetic layer, carbon in which particle diameters of 20 nm and 60 nm are mixed in 1: 1 is dispersed in a binder in which vinyl chloride and urethane are mixed in 1: 1. The resulting coating material was applied to a thickness of 0.5 μm.
After that, it slits to a width of 8 mm, and it is incassed into an 8 mm video tape cassette, and a single frequency of 1 MHz and 7 MHz.
Was recorded and reproduced, and the output (dB) and C / N (dB) were measured by comparison with a commercially available 8 mm reference tape manufactured by Sony Corporation (where the tape is 0 dB).

As a comparative example, 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 μm PET film surface at 1500 Å. However, other conditions were the same as those of the example, and the same measurement was performed. The results are shown in Table 1.

[0021]

[Table 1]

From these results, particularly in the high range (7 MHz), both the output and C / N became large and excellent characteristics were obtained, and the effect of the two-layer vapor deposition was recognized in the one manufactured by the apparatus of this example. Was given. In the above embodiment, the first
And if a small amount of oxygen is introduced from the outside toward the non-magnetic substrate 8 during vapor deposition in the second paths A and B,
Oxidation improves the corrosion resistance of each layer of the magnetic layer,
There is an advantage that the two magnetic layers can be clearly separated.

[0023]

As described above, according to the present invention, two magnetic layers having different column structures are formed by a single evaporation source.
It is possible to continuously form the layers one by one, the vapor deposition efficiency is good, and the productivity is greatly improved. In addition, by providing a cooling plate on the back surface side of the deposition portion of the non-magnetic base material, heat loss of the non-magnetic base material can be prevented and stable deposition can be achieved, which also has the effect of improving productivity. To be

[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 schematic view of a cooling plate in the above embodiment.

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 12 shielding plate 13, 14 cooling plate A 1st route B 2nd route

Claims (2)

[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 path and the second path of the non-magnetic base material from the can to the second guide body are arranged such that the facing distance between the path and the guide body side is narrower than the can side, while the space sandwiched by the first and second paths. A vapor deposition apparatus for a magnetic recording medium, characterized in that an evaporation source of a magnetic material for forming a magnetic layer is disposed in the. 2. A cooling plate for cooling the non-magnetic base material is arranged on the side opposite to the side where the magnetic material evaporation source is located along each of the first and second paths. A vapor deposition apparatus for the magnetic recording medium described.