JPH03183782A - Thin film manufacturing equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to thin film production in which a long polymer film or metallized film is conveyed and a functional thin film is formed thereon to produce a functional film. It is related to the device. More specifically, the present invention relates to a manufacturing apparatus suitable for forming a protective layer and a back coat layer of a metal thin film type magnetic recording medium.

[Prior Art] In recent years, as the recording density of magnetic recording devices has increased, metal thin film types have been developed, in which a magnetic metal thin film layer is formed on a polymer film by a method such as a vacuum evaporation method, a sputtering method, or an ion blasting method. Research and development of magnetic recording media is progressing. Generally, this type of media has problems with corrosion resistance and abrasion resistance, and it is said that providing a protective film is an effective solution to this problem. As methods for forming the protective film, vacuum evaporation, sputtering, ion blating, plasma CVD, and the like have been studied, and various manufacturing apparatuses have been proposed.

The conditions required for the protective film manufacturing apparatus include the following required characteristics.

(i) A thin and dense film can be produced with 100 to 300 people.

(i) Reproducibility and surface stability of film quality (e.g. uniformity)
Be excellent at.

(ii) It is possible to manufacture wide and long sheets at high speed without losing heat.

As a representative example of the prior art, FIG. 3 shows a configuration diagram of a thin film manufacturing apparatus using the plasma CVD method. In this figure, 1 is a vacuum pump, 2 is a vacuum chamber, 3 is a raw material, 4A and 4B are counter electrodes for discharging, 5 is a monomer gas supply port, 6 is a supply roll, 7 is a take-up roll, and 8 is a guide roller, 9
is an AC power source.

In the manufacturing apparatus as described above, a functional thin film is continuously formed on the elongated original fabric 3 pulled out from the supply roll 6 by plasma generated in the space between the counter electrodes 4A and 4B.

[Problems to be Solved by the Invention] However, in the conventional apparatuses described above, for example, a vacuum evaporation apparatus or an ion blating apparatus has the above-mentioned problem (i), and a sputtering apparatus has the above-mentioned problem (ii). In the plasma CVD apparatus, each of the above-mentioned problems (i) remains unresolved, and a thin film manufacturing apparatus suitable for mass production that satisfies the above three conditions is desired.

When we analyzed the causes of the lack of reproducibility of film quality and surface instability, which are problems of the plasma CVD method using the above-mentioned conventional equipment, we found that the protective film material is not suitable for metal thin film magnetic recording media.
It was found that it adhered not only to the surface of the original fabric 3) but also to the surface of the counter electrode 4A, which caused changes in discharge conditions over time and non-uniformity depending on the location of the electrode, resulting in poor film quality. The problem was that it led to instability.

The present invention was made in order to solve the conventional problems as described above, and an object of the present invention is to provide a thin film manufacturing device that can form a stable protective film at high speed without reducing corrosion resistance and wear resistance. That is.

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention has a running system for a raw fabric in a vacuum layer, and continuously forms a functional thin film on the raw fabric by a plasma CVD method. In the manufacturing apparatus, a plurality of electrically insulated metal drums are provided, an AC power source is connected between the drums, and a monomer gas is supplied to the space between the drums at a position in contact with the original fabric. This is a thin film manufacturing apparatus characterized by being provided with a discharge chamber having a supply means.

In the present invention, it is also possible to provide a supply roll and a take-up roll for the original fabric independently for each drum, thereby providing a plurality of original fabric traveling systems.

[Function] According to the configuration of the present invention described above, a plurality of electrically insulated metal drums are provided, an AC power source is connected between the drums, and a space between the drums is connected to the original fabric. Since a discharge chamber with a monomer gas supply means is provided at the contact position, the drums themselves act as counter electrodes, and the raw fabric runs on top of the drums in contact with each other, thereby preventing the attachment of the protective film material. Since this is applied to the original fabric that is drawn out one after another, changes in discharge conditions due to adhesion that occur with conventional fixed counter electrodes do not occur, and a protective film with stable film quality can be formed.

[Example] An example of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the basic structure of a thin film manufacturing apparatus in a first embodiment of the present invention, in which the number of drums is 2.
This is an example. In FIG. 1, 1 is a vacuum pump, 2 is a vacuum tank, 3 is a raw material, 5 is a monomer gas supply pipe, 6 is a supply roll, 7 is a take-up roll, 8 is a guide roller, 9
10A is a metal drum, 10B is a metal drum, and 11 is a discharge chamber.

In the thin film manufacturing apparatus of FIG. 1 configured in this way,
A plurality of electrically insulated metal drums IOA, IOB are provided in the vacuum chamber 2, and the drums IOA, IO
An AC power supply 9 is connected between B and the drum IOA.
, a discharge chamber 11 having a monomer gas supply means 5 is provided in a space between the IOBs and at a position in contact with the original fabric 3.

That is, in the vacuum chamber 2 to which the vacuum pump 1 is connected,
AC power source 9 is provided by providing cooled metal drums IOA and IOB at positions facing each other and electrically insulated from the surroundings.
At the same time, a discharge chamber 11 is provided between the drum 10A and the drum IOB, and one or more monomer gas supply pipes 5 for supplying monomer gas are connected to the discharge chamber 11, and furthermore, a magnetic recording layer is formed. Wide and long raw material 3
A thin film can be continuously formed by providing a feed roll 6 for winding the roll, a take-up roll 7 for winding the roll, and a guide roller 8 for regulating the running of the roll.

The inside of the vacuum chamber 2 is pumped approximately 10't by the vacuum pump 1.

rr, and then monomer gas, such as methane, ethane, cyclohexane, benzene, etc., which can be chemically vapor deposited, alone or in the form of a mixture with argon or hydrogen, is passed through the monomer gas supply tube 5 into the discharge chamber 11 to reduce the vacuum in the discharge chamber. Then, an alternating current voltage is applied between both drums to generate plasma in the discharge chamber 11. At this time, the frequency of the alternating current is preferably several KH2 or more, and the effective voltage is 300V or more. Since the current depends on the discharge area, it cannot be said unconditionally, but
Decide by taking into account the thickness of the protective film and the speed of running the material. The discharge chamber 11 is made of a heat-resistant insulator, and the drum I/O
A. The gap between the IOB and the discharge chamber 11 must be designed to be as narrow as possible so that discharge occurs only within the discharge chamber 11.

As the raw film 3, not only one on which a magnetic recording layer is formed, but also a general polymer film can be used, and the material should be selected depending on the purpose.

For example, in the case of a metal thin film type magnetic recording medium, a thin film can be formed on the magnetic recording layer side for the purpose of a protective film, or a thin film can be formed for the purpose of improving running on the back side. However, in the case of raw material with a metal thin film attached, if the resistance is low, current will flow through the metal thin film, so it is necessary to increase the resistance by increasing the running span from the drum IOA to the next drum 10B. Adjustments will be required. If the resistance is extremely low,
For example, the embodiment shown in FIG. 2 is effective below 2 to 3 Ω. Here, supply rolls 6A, 6B and take-up rolls 7A, 7B are separated for each drum, and a stable discharge state can be obtained regardless of the presence or absence of a metal thin film and the level of resistance.

Next, specific examples and their evaluation results will be described.

A 10 μm thick polyethylene terephthalate film was used as the base material for the original fabric, and cobalt nickel (N
A carbon thin film was deposited by 150 people at a transport speed of 30 m/min on a metal thin film magnetic recording medium material with a width of 500 mm and a length of 3000 m, on which a magnetic film (film thickness: 0.2 μm) was obliquely deposited. A trial production of 50 lots was made using the production equipment in the example. Methane and argon were introduced as monomer gases at 300 m1/min and 100 m1/min, respectively, the degree of vacuum in the discharge chamber was 0.35 torr, the degree of vacuum in the vacuum vessel was 2 x 10 torr, and the frequency was 50K.
H! , voltage is 800m by applying 1200V AC voltage.
A discharge current of A was applied to generate plasma. The drum was cooled to 15°C to prevent heat loss.

The sample prepared under these conditions was cut to a width of 172 inches, and samples were taken at 5 points in the width direction and 7 points in the longitudinal direction at each loft.

In order to examine in-plane stability of durability and reproducibility between lots, the still life of each sample was measured using a video deck in an environment of 23° C. and 70%. In order to further examine the corrosion resistance, these samples were left in a high temperature, high humidity tank at 60°C and 90% for one week, and then the still life was measured in the same manner.

In both tests, still lifespans of 30 minutes or more were obtained for all samples, and considering this, considering that in the past, still lifespan failures of 30 minutes or less occurred at a rate of nearly 30%, the device of this example According to the results, a dramatic improvement effect can be obtained.

Further, in the device of this example, the protective layer inevitably has a structure of two or more layers, but it was confirmed that there was no problem in terms of performance.

Although this example describes two drums, it is not limited to this, and is also effective with multiple drums. Although the device becomes slightly more complex, the conveyance speed of the original fabric is improved. There are benefits to doing so.

Next, a second embodiment of the present invention will be described.

In FIG. 2, 6A is a supply roll, 6B is a supply roll, 7A is a take-up roll, and 7B is a take-up roll, and the other parts or devices are the same as in FIG. 1.

In the thin film manufacturing apparatus configured in this way, each drum has supply rolls 6A and 6B for the original fabric, and a take-up roll 7.
A and 7B are provided independently, and a plurality of web traveling systems are provided. By doing so, it is possible to twist two lines of raw fabric at the same time, and it is possible to achieve the effect of improving the efficiency of the apparatus.

[Effects of the Invention] As explained above, according to the present invention, a plurality of electrically insulated metal drums are provided, an AC power source is connected between the drums, and the space between the drums is Since a discharge chamber with a monomer gas supply means is provided at a position in contact with the film, the drums themselves act as counter electrodes, and the raw film runs on top of the drums in contact with each other, allowing the protective film material to Since the adhesion is made to the newly drawn raw material one after another, the change in discharge conditions due to adhesion that occurs at the fixed counter electrode does not occur, and a protective film with stable film quality is formed. As a result, a thin, dense film can be uniformly formed at high speed, making the device extremely suitable for mass production as a protective film manufacturing device, and making a significant contribution to the practical application of metal thin film magnetic recording media.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a thin film manufacturing apparatus according to a first embodiment of the present invention, FIG. 2 is a block diagram of a thin film manufacturing apparatus according to a second embodiment of the present invention, and FIG. 3 is a diagram of a conventional thin film manufacturing apparatus. FIG. 1... Vacuum pump 2... Vacuum tank 3... Original fabric 5... Monomer gas supply pipe 6... Supply roll 7... Winding roll 8... Guide roller 9... AC Power supply 10A, IOB...Metal drum 11...Discharge chamber 6A...Supply roll 6B...
Supply roll 7A...Take-up roll 7B...Take-up roll Fig. 2

Claims (2)

[Claims] (1) In a manufacturing apparatus that has a running system for the original fabric in a vacuum layer and that continuously forms a functional thin film on the original fabric by plasma CVD method, a plurality of electrically insulated metal drums are used. A thin film manufacturing apparatus characterized in that an AC power source is connected between the drums, and a discharge chamber having a monomer gas supply means is provided in a space between the drums and in contact with the original fabric. . (2) The thin film manufacturing apparatus according to claim 1, wherein a supply roll and a take-up roll for the original fabric are provided independently for each drum, and a plurality of original fabric traveling systems are provided.