JPH01245427A - Method and device for manufacturing magnetic recording medium - Google Patents

Abstract

PURPOSE:To form a homogeneous film having an excellent adhering efficiency over a long period by forming the protective layer of a magnetic recording medium by sputtering while an electric current is supplied to a ferromagnetic metallic thin film layer of the medium. CONSTITUTION:When the protective film of a magnetic recording medium 10 is formed by sputtering after a ferromagnetic metallic thin film layer 2 is formed, the sputtering is performed while an electric current is supplied to the ferromagnetic metallic thin film layer 2. Moreover, since this device supplies the electric current to the ferromagnetic metallic thin film layer 2, a power source 28 is provided to supply the current at an appropriate part of a mobile device which is brought into contact with the magnetic recording medium 10, for example, one of rolls 21-25 which are brought into contact with the metallic thin film layer 2. Thus the homogeneous protective layer 4 can be formed for a long length while the film forming speed is increased without raising the temperature of a base plate 1.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a method and apparatus for manufacturing a ferromagnetic metal thin film type magnetic recording medium, and in particular to a method and apparatus for manufacturing a ferromagnetic metal thin film type magnetic recording medium, and in particular to a method and apparatus for manufacturing a ferromagnetic metal thin film type magnetic recording medium. The present invention aims to provide a method and apparatus for manufacturing a magnetic recording medium that significantly reduces defects.

Conventional technology Co, Ni, Fe, or alloys containing these as main components are deposited on polymer films such as polyester films, polyimide films, and non-woven materials by vacuum deposition methods such as vacuum evaporation, sputtering, and ion blasting. A ferromagnetic metal thin film type magnetic recording medium formed on a substrate made of a magnetic metal or the like can dramatically improve recording density compared to conventional coating type magnetic recording media.

By the way, as a condition for increasing the recording density, it is important to reduce recording/reproduction defects as much as possible and to reduce spacing loss between the magnetic head and the magnetic recording medium as much as possible. Furthermore, the magnetic recording medium must also have durability. Conventionally, in order to satisfy these conditions, a protective layer has been formed after forming the magnetic layer, and a sputtering method is known as a method for forming the protective layer. FIG. 4 shows a magnetic recording medium 10 in which layers are formed by a conventional sputtering method, where ■ is a substrate, 2 is a ferromagnetic metal thin film layer formed by a vacuum film forming method, 3 is a back coating layer, and 4 is a A protective layer formed by sputtering,
5 is a lubricant layer formed after the formation of the protective layer 4.

Next, an example of the conventional method and apparatus for manufacturing the above-described magnetic recording medium will be described with reference to FIGS. 4 and 5.

FIG. 5 shows a manufacturing apparatus, in which 10a is a magnetic recording medium before the formation of a protective layer, which is wound around a feeding roller 11. 12 and 14 are bus rollers, and 13 is a main roller that conveys the magnetic recording medium 10 in close contact with each other. Reference numeral 15 denotes a winding roller that continuously winds up the magnetic recording medium 10b on which a protective layer has been formed. Reference numeral 16 denotes a sputtering target, which is made of a protective layer forming material such as metal, carbide, or fluoride. Reference numeral 17 denotes a sputtering power source, which is provided outside the vacuum chamber.

A method of manufacturing a magnetic recording medium using the conventional apparatus configured as described above will be described.

The magnetic recording medium 1 (la), which has not yet been formed with a protective layer, is fed out from the feeding roller 11 and conveyed to the processing area through the bus roller 12 in close contact with the main roller 13. Target material molecules are released from the magnetic recording medium 10, and the molecules adhere to the surface of the magnetic recording medium 10 to form the protective layer 4. Then,
The magnetic recording medium 10b on which the protective layer 4 is formed is continuously wound up by a take-up roller 15 via a bus roller 14.

Problems to be Solved by the Invention However, in the conventional example described above, the collision of the target material molecules with the magnetic recording medium 10 causes a rise in temperature, which not only deteriorates the film quality and adhesion strength of the protective layer 4 itself, but also deteriorates the ferromagnetic metal. This has the drawback of damaging the thin film layer 2 and furthermore the substrate 1 supporting it, accelerating its deterioration, and eventually leading to the cutting of the magnetic recording medium 10, making it impossible to process it. When recording and reproducing the magnetic recording medium 10 in a part that is far from being commercially practical and cannot be cut, dropouts, increased head clogging, decreased still life, and deterioration of corrosion resistance are noticeable, and magnetic recording The medium 10 will have a serious defect.

In sputtering, it is necessary to raise the temperature of the substrate 1 in order to improve the film formation rate and adhesion strength, and in batch processing, it is necessary to use a heat-resistant substrate material and apply bias current to the substrate 1. It has been put into practical use by et al. However, in the magnetic recording medium 10 that is the object of the present invention, when the substrate temperature is increased to improve the film formation rate, the magnetic recording medium 10
The substrate 1 constituting 0 is damaged by heat, leading to the cutting of the magnetic recording medium, making it impossible to process, and therefore cannot be put to practical use in industry.

In view of the drawbacks of the conventional examples and the characteristics of magnetic recording media, the present invention makes it possible to suppress the temperature rise of the substrate as much as possible and to process a protective film with high adhesion strength over a long length. It is an object of the present invention to provide a method and apparatus for manufacturing a magnetic recording medium that improves still durability and corrosion resistance while reducing clogging.

Means for Solving the Problems In order to achieve the above object (2), the method for manufacturing a magnetic recording medium of the present invention includes the steps of forming a protective film of the magnetic recording medium 10 by sputtering after forming the ferromagnetic metal thin film layer 2. The sputtering process is performed while energizing the ferromagnetic metal thin film layer 2. Also, the apparatus for performing this manufacturing method is in contact with the magnetic recording medium 10 in order to energize the ferromagnetic metal thin film layer 2. suitable parts of the transfer device, e.g. ferromagnetic metal N
8 Rolls 21.22.23.24.25 in contact with layer 2
A power source 28 is provided to supply power to either of the two.

Function The present invention improves the film formation rate by applying electricity to the ferromagnetic metal thin film layer 2 of the magnetic recording medium 10 without increasing the temperature of the substrate 1, while forming a homogeneous protective layer 4 over a long length. It has been found that the magnetic recording medium 10 not only reduces dropouts and head clogging as recording/reproduction defects, but also improves still durability and #I corrosion resistance. This not only significantly improves performance, but also allows it to be used in areas with plenty of room for practical use.

EXAMPLES Hereinafter, examples of the present invention will be described with reference to FIGS. 1 to 3 of the drawings.

FIG. 1 shows an apparatus for forming a protective layer on a ferromagnetic metal thin film layer according to the present invention by sputtering while applying electricity to the ferromagnetic metal thin film layer. Since the basic structure of the recording medium 20 is the same as the conventional one, the fourth
To explain with reference to the figure, a 3-20 μm PET film is used as the substrate 1, and a 0.1-0.2 μm Co
- forming a ferromagnetic metal thin film layer 2 by oblique evaporation of Ni;
A magnetic recording medium 2 in which a back coating layer 3 made of a mixture of resin and carbon is formed on the back surface to improve running performance.
0, and a protective layer 4 and a lubricant layer 5 are formed on the ferromagnetic metal thin film layer 2.

In FIG. 1, 20a is a magnetic recording medium before the formation of a protective layer, which is wound around a feeding roller 21, and the tension from this feeding roller 21 is approximately 0 at a width equivalent to 5001 mm.
．． It is controlled by a tension roller at 5 to 20 kgf and sent out. 22.24 is a bus roller and magnetic recording medium 2
ferromagnetic metal thin film layer 2 and rotates. 23 is a main roller that moves the magnetic recording medium 20 at a constant speed (0,1 to 2001
The rotation is controlled to convey at a speed of 1/min). 25 is
This is a take-up roller that continuously winds up the magnetic recording medium 20b on which a protective layer has been formed, and the tension is 0.05 mm for a width equivalent to 500 nn.
It is controlled to 5 to 20 kgf, and it is also possible to control the taper tension. Each of the aforementioned rollers 21, 22, 23, 24, 25
and these rollers 21, 22, 23, not shown.
The transfer device is constituted by the rotation drive mechanism of 24 and 25. 2G is a sputtering target, and a metal, carbide, fluoride, or the like is used as a material for forming the protective layer. Reference numeral 27 denotes a sputtering power supply, which applies a voltage with an effective value of 0.7 to 7 KV to the sputtering target 26 by DC, ACXRF, or a combination thereof. A sputtering target 26 and a sputtering power source 27 constitute a sputtering processing apparatus. 28 is a power supply for energizing the ferromagnetic metal thin film layer 2, which supplies DC-0.1 to -3KV;
Power is supplied from the bus roller 24 and the winding roller 25 around which the magnetic recording medium 20 is wound after the protective layer is formed. Note that it is also possible to configure this power supply to be performed via the rollers 21, 22, and 23 of the pond.

Next, a method of manufacturing the magnetic recording medium 20 using the manufacturing apparatus configured as described above will be described with reference to FIG. 1, together with the operation of the manufacturing apparatus. The magnetic recording medium 20a before the formation of the protective layer is supplied with power from the bus roller 24 and the take-up roller 25 in order to form the protective layer 4 on the ferromagnetic metal thin film layer 2, and is continuously brought into close contact with the main roller 23 in the energized state. will be sent. The magnetic recording medium 20 is connected to the main roller 2
When reaching the protective layer forming area No. 3, the sputtering target 2
Molecules from 6 collide. These sputtered molecules for forming the i-layer are emitted by ions generated by the sputtering power source 27, but they are
Since the ferromagnetic metal thin film layer 2 is energized, the adhesion efficiency is good, and molecular collisions can be controlled by adjusting the power supply voltage, so the adhesion strength can be maintained without damaging the ferromagnetic metal thin film layer 2. Increases speed. In addition, the above-described energization improves the adhesion between the main roller 23 and the magnetic recording medium #20, and due to the synergistic effect of increasing the film forming speed,
The temperature rise is small, and the film can be continuously formed up to a length that reaches the limit of the mechanical system.

As described above, according to the present invention, the ferromagnetic metal thin 115 of the magnetic recording medium! After the layer is formed, a protective layer is formed on the ferromagnetic metal thin film layer by sputtering while applying electricity to the ferromagnetic metal thin film layer, thereby reducing the temperature rise of the substrate and speeding up the film formation, as shown in Table 1. Stabilization results in significant improvements in processable length and film formation rate.

Table-1 Note) Film formation speed is selected based on the voltage applied to the sputtering target O: 5000I1 or more OK (up to equipment limit)
Δ: Cutting at 1000-5000Il X: Cutting at 1000n or less FIG. It is recognized that the still durability is improved and stabilized by improving the adhesion strength. Furthermore, Fig. 3 shows a comparison of the corrosion resistance of magnetic recording media manufactured by the present invention and a conventional example under conditions of an air temperature of 60°C and a humidity of 90%.The improvement in corrosion resistance in the present invention is remarkable. An improvement of about 3 times is observed when judged by the degree to which rust contaminates the head during running in a video tape recorder. In addition, other experiments have also confirmed that there is a correlation between the degree of contamination of the head and the lifespan of the recording medium. Furthermore, in the magnetic recording medium according to the present invention, reductions in dropouts and head clogging as recording/reproduction defects were also observed.

Effects of the Invention As described above, according to the present invention, by forming the protective layer by sputtering while applying electricity to the ferromagnetic metal thin film layer of the magnetic recording medium, a homogeneous film with good adhesion efficiency can be formed for a long time. This makes it possible to achieve industrial practical application. Also,
A magnetic recording medium manufactured according to the present invention has reduced dropouts and head clogging as recording/reproducing defects, improved still durability and corrosion resistance, and has excellent stability.

[Brief explanation of the drawing]

Figure 1 is a schematic diagram showing the manufacturing equipment used in one embodiment of the present invention, Figure 2 is a comparative diagram comparing the relationship between still life and load between the conventional method and the method of the present invention, and Figure 3 is a diagram showing the corrosion resistance as well. Fig. 4 is a cross-sectional view showing the structure of a magnetic recording medium, and Fig. 5 is a diagram showing the manufacture of a conventional magnetic recording medium. FIG. 2 is a schematic diagram showing the device. 20...Magnetic recording medium 20a...Magnetic recording medium before protective layer formation 2Qb...Magnetic recording medium with protective layer formed
21...Feeding roller 22.24-...Pass roller 23...Main roller 25...Take-up roller 26...Target for sputtering 27...Power source for sputtering 28...Power source for energizing 22-- -/Zu Slower Figure 1 △, L# - Illusion/1 of 2 Random Life (Intermediate) @ Figure 2 Figure 3 Figure 4 Figure 5

Claims (2)

[Claims] (1) A method for manufacturing a magnetic recording medium, in which a ferromagnetic metal thin film layer is formed on a substrate, and a protective layer is continuously formed on the ferromagnetic metal thin film layer by a sputtering method, wherein the ferromagnetic metal thin film layer A method of manufacturing a magnetic recording medium, characterized in that the protective layer is formed in a state where electricity is applied to the magnetic recording medium. (2) A transport device for transporting a magnetic recording medium having a ferromagnetic metal thin film layer formed on a substrate in a fixed direction, and a sputtering method to protect the ferromagnetic metal thin film layer on the transport path of the magnetic recording medium. In a magnetic recording medium manufacturing apparatus equipped with a sputter processing apparatus for forming a layer, power is supplied to an appropriate contact part with the magnetic recording medium in the transfer apparatus in order to energize the ferromagnetic metal thin film layer. Features: Magnetic recording media manufacturing equipment.