JP2987406B2 - Film forming method and film forming apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a manufacturing apparatus for forming a magnetic recording medium having high durability, high recording density, and excellent mass productivity on a polymer substrate material. It covers a wide variety of fields such as video equipment and information equipment.

[0002]

2. Description of the Related Art In recent years, magnetic recording media have tended to have higher densities.
Γ-Fe ₂ O ₃ powder used for video tape material,
A coating type in which CrO powder, pure iron powder, and the like are coated on a polymer substrate material together with an abrasive and a binder has been used. However, in order to improve not only the density, but also the coercive force, electromagnetic conversion characteristics, and the like, By a method called PVD in a broad sense, such as a vacuum deposition method, a plating method, an ion plating method, and a sputtering method, a magnetic metal such as Fe, Ni, Co, or Cr has high productivity and is a stable metal thin film. It is formed as a mold magnetic layer.

[0003] Also, a diamond-like carbon film is formed by the above-mentioned various PVD methods or CVD methods typified by the plasma CVD method.

[0004]

However, it is difficult to obtain a laminated thin film having good interface characteristics and surface characteristics while maintaining a high film formation rate by the above method and apparatus.
Development of a new technology has been urgently required because of problems such as an open-to-atmosphere process and the fact that it is technically difficult to synchronize the magnetic layer and the diamond-like carbon film because the film formation speeds thereof are greatly different.

[0005]

SUMMARY OF THE INVENTION The present invention provides an organic and rational method of controlling a discontinuous method using a plurality of different film forming steps by controlling a differential pressure of an operating pressure between the steps to a desired value. It is possible to mass-produce a highly reliable magnetic recording medium that has isotropic magnetic properties in in-plane recording and is integrally connected while being divided into interconnected and synchronized film formation areas.

[0006]

According to the present invention, the film forming region consisting of a plurality of steps, that is, the operating pressure of the vacuum vessel is stepped or inclined, so that the vacuum device can be normally and functionally operated, and the film forming position can be improved. Therefore, a highly efficient method can realize a high effect, that is, formation of a group of laminated thin films having interface characteristics, adhesion, surface characteristics, and the like.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS. In FIG. 1, a polymer substrate material 3 sent from a supply roll 2 in a vacuum vessel (1) 1 travels in a direction of an arrow along a cylindrical can 7 via a free roller guide 4.

In this embodiment, a polyimide film having a width of 50 cm and a thickness of 6 μm was used as the polymer substrate material 3.

The metal atoms evaporated from the evaporation source 6 are deposited on the polymer substrate material 3 to form a magnetic layer 21 (see FIG. 2) with a thickness of 0.15 to 0.18 μm.

In this embodiment, Co-C is used as an evaporating substance.
Using an r-Ni alloy, a pierce-type electron gun capable of scanning over a wide range, and applying an accelerating voltage of 35 KV, 5 × 10 ⁻⁴ Torr
Formed by an electron beam evaporation method at an operating pressure of. The passing speed of the polymer substrate material 3 was 135 m / min. In addition,
The shielding plate 5 is provided to limit the deposition area.

A DC power supply 1 is provided between the cylindrical can 7 and the formed magnetic layer 21 via a free roller guide 4.
5, a voltage of 80 V was applied so that the polymer substrate material 3 and the cylindrical can 7 were electrostatically adhered to each other. Polymer substrate material 3 on which magnetic layer 21 is formed
Is guided to the vacuum vessel (2) 9 via the intermediate roll 8, and is subjected to plasma activation processing.

Here, the plasma activation process will be described. A source gas supply system 18 is provided between electrodes in which a ground electrode 10 and a high-frequency power supply electrode 11 are arranged in parallel at an interval of 3 cm.
The operating pressure was controlled to 10 ^-1 to 10 ^-2 Torr while introducing hydrogen gas from the exhaust system 19 and evacuating the exhaust system 19 to 13.56 MHz.
High frequency power system 1 at a power density of 0.5 W / cm ²
2 to form a hydrogen plasma, and the polymer substrate material 3 passes through the plasma region 16 at a speed synchronized with the magnetic layer forming step.

By performing this step, the surface of the magnetic layer 21 is not only appropriately cleaned by being exposed to active hydrogen radicals or hydrogen ions, but also is
Activation of one surface is promoted. Similar effects were confirmed for argon gas and a mixed gas of argon and hydrogen. The size of the gap through which the polymer substrate material 3 formed on the wall separating the vacuum chamber (2) 9 and the buffer chamber 20 should pass depends on the plasma 16 generated in the vacuum chamber (2) 9.
Or the mean free path at the pressure of the plasma region 16. Then, the plasma does not leak into the buffer chamber 20.

Further, the vacuum vessel (3) 13, which is a region where the diamond-like carbon film 22 is formed in the present invention, will be described. Magnetic layer 2 guided via free roller guide 4
The high quality diamond-like carbon film 22 is formed on the polymer substrate material 3 on which 1 is deposited while passing through the sheet beam type plasma region 17.

Here, the sheet beam type plasma region 17
An example of a specific condition for the means for generating is shown.

The operating pressure was controlled at 1 Torr by using ethylene gas as a carbon source between electrodes in which the ground electrode 10 and the high-frequency power supply electrode 11 were precisely arranged in parallel at an interval of 1 cm. Further, the ground electrode 10 has a hollow structure, and the size of the blowing portion of the raw material gas is 0.5 to 1.0 cm in width and 60 c in length.
m is processed into a slit shape with high precision, and a high-frequency power having a power density of 3 W / cm ² is applied from the high-frequency power supply system 12 to locally generate a linear high-luminance emission plasma region. 20 with a passing speed linked to the two processes
Winding roll 1 made of diamond having a thickness of 0 °
Collected via 4. Here, it is important that the polymer substrate material 3 runs on the high-frequency power supply electrode 11.

When the diamond-like carbon film 22 is formed on the film-formed substrate, that is, on the polymer substrate material 3, the high-frequency power supply electrode 11 provided with the substrate having the surface to be formed is provided.
In the vicinity of, due to differences in mobility, mass, and the like, among molecules, atoms, positive and negative ions, electrons, radicals, and the like in the plasma, electrons are generated not only on the high-frequency power supply electrode 11 but also on the surface of the formation surface. Positive ions accelerated by the electric field generated between the self-bias and the plasma potential (plasma potential) collide with the diamond-like carbon film being formed, thereby promoting a physical and chemical reaction,
By reducing the proportion of carbon having a double bond such as C = C and increasing the proportion of carbon having a CC bond, high quality of the coating can be obtained.

Further, by running the polymer substrate material 3 on the high-frequency power supply electrode 11 at a predetermined speed, the film-forming substrate is fixed, that is, when the film-forming substrate is formed at a high speed by a static forming method. Thus, the problem of thermal damage to the substrate on which the film is formed can be solved.

FIG. 2 is a cross-sectional view of the magnetic recording medium manufactured in the above-described film forming step, and the interface characteristics between the magnetic layer 21 and the diamond-like carbon film 22 were significantly improved.

FIG. 3 shows a Raman spectrum of the diamond-like carbon film 22 obtained in the embodiment of the present invention, and shows that the film quality is good despite the high-speed deposition.

In practicing the present invention, the treatment before the formation of the magnetic layer 21 can be performed by using a known technique such as irradiation with ions and electrons or heating, if necessary. As the substrate, for example, a polyimide film is used in this embodiment, but a metal resin, a plastic, or the like may be formed in a roll shape or a plate shape.

FIG. 4 shows the result of evaluating the dependence of the reproduction output on the film thickness of the diamond-like carbon film 22 by changing the recording frequency. The reproduction output is saturated in a region where the film thickness of the diamond-like carbon film 22 exceeds 200 °. , Suggesting the importance of surface smoothness.

Further, the produced magnetic recording medium was cut into an 8 mm wide tape and evaluated for reproduction output and durability using a commercially available 8 mm video deck. In the above,
Stable playback output with low drop-up and excellent running stability and still durability was obtained.

Further, it was confirmed that excellent durability was exhibited in continuous and intermittent tests of special reproducing operations in addition to the normal reproducing operation.

[0025]

As is clear from the above description, the magnetic recording medium manufactured by the manufacturing apparatus of the present invention has improved interface characteristics and adhesion between the magnetic layer 21 and the diamond-like carbon film 22. By simply avoiding further exposure to the atmosphere, the magnetic layer 2
Although lower oxides generated on one surface cannot be essentially removed, it was also confirmed that the plasma activation treatment according to the present invention was effective.

Further, the surface characteristics of the diamond-like carbon film 22, that is, abrasion resistance, high smoothness, hardness and the like are remarkably improved, and it is possible to manufacture a magnetic recording medium of industrially sufficient value. The rule point on continuous formation, which had been performed, could also be avoided.

[Brief description of the drawings]

FIG. 1 is a sectional view schematically showing the internal structure of a magnetic recording medium manufacturing apparatus according to an embodiment of the present invention.

FIG. 2 is a sectional view of a magnetic recording medium obtained in an embodiment of the present invention.

FIG. 3 shows a Raman spectrum of a diamond-like carbon film in a magnetic recording medium obtained in an example of the present invention.

FIG. 4 is data showing the dependence of the reproduction output of a magnetic recording medium obtained in an example of the present invention on the thickness of a diamond-like carbon film.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Vacuum container (1) 2 ... Supply roll 3 ... Polymer substrate material 4 ... Free roller guide 5 ... Shield plate 6 ... Evaporation source 7 ... Cylindrical can 8・ ・ ・ Intermediate roll 9 ・ ・ ・ Vacuum container (2) 10 ・ ・ Ground electrode 11 ・ ・ High frequency power supply electrode 12 ・ ・ High frequency power supply system 13 ・ ・ Vacuum container (3) 14 ・ ・ Winding roll 15 ・ ・ DC power supply 16 ・ ・ Plasma region 17 ・ ・ Sheet beam type plasma region 18 ・ ・ Raw material supply system 19 ・ ・ Exhaust system 20 ・ ・ Buffer room

Continued on the front page (58) Fields investigated (Int.Cl. ⁶ , DB name) G11B 5/84 C23C 14/06 G11B 5/85 H01F 41/20

Claims (5)

(57) [Claims] 1. A magnetic layer and a diamond-like carbon film on a substrate.
A film forming apparatus for continuously laminated, comprising: a first vacuum chamber that form a magnetic layer, a second vacuum chamber that form a diamond-like carbon film, at least,
It said first differential pressure operation force of the vacuum container and the second vacuum vessel 10 -2 ^{to 10} -5 ^Torr the film forming apparatus you characterized in that it is in the range of. 2. A plasma activation process according to claim 1, wherein a plasma activation process is performed between said first vacuum vessel and said second vacuum vessel.
Cormorant film forming apparatus characterized in that a third vacuum vessel. 3. A film forming apparatus according to claim 1, further comprising a sheet beam type plasma region generating means in said second vacuum vessel. 4. established a film of an organic resin rolled feeding the roll, feeding the winding roll the film through the gas Idororu, roll-to-roll by rotating the take-up roll to wind the film using equation film processor, the film forming method for forming a diamond-like carbon film on said film, said diamond-like carbon film coating, characterized in that it is formed by a plasma region generating means shaped sheet beamforming Method. 5. The delivery roll according to claim 4, wherein
Film to be installed in the film forming apparatus according to claim Rukoto which have a magnetic layer.