JP2000239850A - Continuous plasma cvd device and continuous plasma cvd method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To longly control the protecting film of a thin film to be continuously formed by providing guide rolls adjacent to a rotary drum on the feeding side and coiling side in a running roll system with potential detectors. SOLUTION: A long and wide substrate 1 having electrical conductivity is continuously supplied from a feed roll 2, and film formation is executed through the circumferential face of a rotary drum 3 in a cooled state. Gaseous hydrocarbon is introduced from a gas introducing port 5, carrier gas is introduced from a gas introducing port 6, and they are mixed. The rotary drum 3 is applied with self bias voltage by a high-frequency power source 11 via a blocking capacitor 12, and these gases are held to the state of plasma in a film forming chamber. In this way, a plasma CVD film is continuously formed on the substrate 1. At this time, adjacent guide rolls 9 and 10 respectively on the feeding roll side and soiling side in the rotary drum 3 are provided with potential detectors 7 and 8, respectively. The film thickness of a plasma CVD film formed by the potential difference before and after the film formation is controlled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous plasma CVD apparatus and a continuous plasma CVD method capable of forming a film in a wide range at a high speed, and more particularly to a wide flexible magnetic film using a ferromagnetic metal thin film as a magnetic recording layer. Continuous plasma CV capable of high-speed deposition of a surface protective film with high durability and low internal stress on a long web surface of tape over a wide range
It relates to the method D and the apparatus.

[0002]

2. Description of the Related Art As a magnetic tape, a thin film magnetic recording medium or various ferromagnetic films are used on a film substrate having an insulating property, and various tapes have been put to practical use.

On the other hand, in recent years, with the miniaturization of computers, magnetic recording media used for external recording devices have been required to have higher recording densities. Therefore, it is necessary to reduce the thickness of the magnetic recording circuit and increase the coercive force. In the case of a magnetic tape, the load applied to the medium surface is becoming severe, such as a method of increasing the relative speed between the head and the medium or the number of heads, and further improving the surface smoothness of the base film.

In order to solve this problem, sputtering, ion plating, vapor deposition, and plasma CVD are performed on the substrate.
Studies have been made on forming a carbon protective film on the surface by using various vapor deposition methods such as a method. Especially, plasma CVD
The method is preferable, and a wide film can be stably formed at a high speed.

Conventionally, it has been difficult to control the thickness of a thin film of at least 30 nm or less by using the film forming method. Heretofore, a light transmission method has been used for general film thickness control. However, in this method, it is impossible to control the thickness of the protective film formed on the magnetic tape, and this is a breakthrough for further improving the productivity.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to overcome the drawbacks of the prior art and to provide a continuous plasma CVD apparatus and a continuous plasma CVD method capable of controlling the length of a continuously formed thin protective film. It is to provide.

[0007]

Means for Solving the Problems In order to achieve the above object, a first invention is a method for continuously forming a film by plasma on a conductive substrate surface which moves on the peripheral surface of a rotary drum via a roller system. In a plasma CVD apparatus, by providing a potential detector on a guide roll adjacent to a rotating drum on a supply side and a winding side of the traveling roll system,
It is possible to provide a continuous plasma CVD apparatus capable of controlling the length of a continuously formed thin protective film.

[0008] To achieve the above object, a second invention provides
In a continuous plasma CVD method in which a film is continuously formed by plasma on a surface of a conductive substrate that moves on the peripheral surface of a rotating drum via a roller system, the traveling roll system is adjacent to a rotating drum on a supply side and a winding side of the traveling roll system. By providing a potential detector on the guide roll and controlling the continuously formed thin film, it is possible to provide a continuous plasma CVD method capable of controlling the length of the continuously formed thin film protective film.

In the present invention, by interposing a blocking capacitor between the base and the high-frequency power supply of the base,
High-speed film formation can be performed with a more stable wide width.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In a plasma CVD apparatus for continuously forming a carbon protective film, for example, on a conductive substrate surface made of a ferromagnetic thin film magnetic material by plasma, the present invention relates to a thin film formed continuously. A continuous plasma CVD apparatus having a substrate transport system while electrically monitoring the thickness, and a continuous plasma CVD method characterized by continuously forming a film while applying a self-bias voltage to the substrate. It is.

In order to achieve the above object, it has been found that the thickness of a continuously formed thin film can be controlled by providing a potential detection system on a guide roll adjacent to a rotating drum.

FIG. 1 is a structural view of an RF plasma CVD apparatus for continuously forming a plasma CVD film of the present invention, and FIG.
FIG. 3 is a diagram illustrating a relationship between a voltage difference before and after film formation and a film thickness measured by a potential detector.

Hereinafter, description will be made sequentially. A long substrate 1 having a long width and conductivity is continuously fed out from a supply roller 2, a film is formed through a peripheral surface of a cooled rotating drum 3 rotating at a predetermined speed, and is wound around a winding roll 4. .

A monomer gas comprising a hydrocarbon-based gas such as ethylene, methane, etc. is introduced through the gas inlet port 5 in FIG. 1, and hydrogen, argon, etc. is introduced through the other gas inlet port 6. A carrier gas composed of an active gas is mixed at a predetermined ratio.

A self-bias voltage is applied to the rotating drum 3 by a high-frequency power supply 11 via a blocking condenser 12, and these gases are kept in a plasma state inside the film forming chamber. From this, plasma CVD on the substrate is continuously performed.
A film is formed.

The potential detectors 7 and 8 of the present invention are provided on adjacent guide rolls 9 and 10 on the supply roll side and the winding side of the rotary drum of the present apparatus, and are continuously formed by a potential difference before and after film formation. The thickness of the plasma CVD film can be controlled.

When a magnetic recording medium is manufactured by the continuous plasma CVD apparatus of the present invention, a synthetic resin film such as polyaramid, polyimide, polyethylene terephthalate, or the like is used as a base for the substrate 1. A magnetic layer of, for example, Co-O, Co-Cr, Co-Ni, or the like is formed thereon, and a conductive film is formed. A long substrate 1 unwound from a supply roll having this magnetic layer
First, a plasma CV having a predetermined film thickness by a plasma CVD method.
The D protective film is formed continuously.

FIG. 2 is a diagram showing the relationship between each film thickness and the potential difference when a diamond-like carbon protective film was formed according to the present invention. The film formation conditions at this time were as follows: a substrate having a 0.15 μm-thick Co—O magnetic layer formed on polyethylene terephthalate was used; To 5 × 10 ^-5 mba
r, The film was formed at a vacuum degree of 0.07 Torr in the film forming chamber.

As a result, the relationship between the potential difference and the film thickness is almost proportional, although there is some variation.

As is clear from the above results, by keeping the potential difference before and after the film formation constant, it is possible to control the film thickness as intended. As described above, according to the present embodiment, the plasma CVD protective film is continuously formed, and it is possible to control the thickness according to the set film thickness.

The present invention is not limited to the above embodiment. For example, in the above embodiment, the diamond-like carbon protective film is mentioned, but in a wide field of thin film magnetic recording media and various functional media using a film having an insulating property by a plasma CVD method,
It is considered that a similar effect can be obtained. That is, a similar effect can be expected for controlling the film thickness to at least 30 nm or less.

[0023]

As described above, according to the continuous plasma CVD method of the present invention, for example, a thin diamond-like carbon protective film can be formed continuously at a set film thickness, which is excellent in mass production. effective.

[Brief description of the drawings]

FIG. 1 shows continuous plasma CVD according to an embodiment of the present invention.
It is a schematic structure figure of an apparatus.

FIG. 2 is a diagram showing a relationship between a potential difference and a film thickness.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Supply roll 3 Rotary drum 4 Take-up roll 5, 6 Gas inlet 7, 8 Potential detector 9, 10 Guide roll 11 High-frequency power supply 12 Blocking condenser

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K030 AA10 AA16 BA28 BB11 CA07 CA12 FA01 GA05 HA01 JA17 KA20 KA39 LA01 LA20 5D112 AA07 AA22 BC05 FA10 FB25 FB26

Claims (8)

[Claims] 1. A continuous plasma for continuously forming a thin film by exposing a conductive flexible substrate surface running along a rotatable drum via a roller system disposed in a vacuum layer to a plasma. In CVD equipment,
A continuous plasma CVD apparatus characterized in that a potential detector is provided on a guide roll adjacent to a rotating drum on a supply side and a winding side of a traveling roll system. 2. The continuous plasma CVD method according to claim 1, wherein the rotating drum on the supply side and the winding side of the traveling roll system is electrically insulated from a vacuum layer.
apparatus. 3. The continuous plasma CVD apparatus according to claim 1, wherein a blocking capacitor is interposed between the substrate and a power supply for applying a high frequency to the substrate. 4. The continuous plasma CVD apparatus according to claim 1, wherein RF is applied by an RF oscillator connected to a rotating drum electrically insulated from the vacuum layer. 5. A continuous plasma for continuously forming a thin film by exposing a conductive flexible substrate surface running along a rotatable drum via a roller system disposed in a vacuum layer to a plasma. In CVD equipment,
A continuous plasma CVD method characterized in that a potential detector is provided on a guide roll adjacent to a rotary drum on a supply side and a winding side of a traveling roll system to control a continuously formed thin film. 6. The continuous plasma C according to claim 5, wherein the rotary drums on the supply side and the winding side of the roll system are electrically insulated from the vacuum layer main body.
VD method. 7. The continuous plasma CVD method according to claim 5, wherein a blocking capacitor is interposed between the substrate and a power supply for applying a high frequency to the substrate. 8. The continuous plasma CV according to claim 5, wherein RF is applied by an RF oscillator connected to a rotating drum electrically insulated from the vacuum layer.
D method.