JPH011118A - magnetic disk - 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 magnetic disks used in memories of large-scale computers, consumer computers, personal computers, etc., particularly magnetic disks using highly wear-resistant materials such as diamond particles. The present invention relates to a magnetic disk in which a lubricating film made of a self-lubricating substance such as amorphous carbon is provided on a magnetic layer.

[Prior Art] Magnetic disks require strict mechanical properties (such as hardness, distortion, processing characteristics, etc.) and chemical properties for the magnetic disk itself or its manufacturing process in order to ensure its usage environment and long-term reliability. Properties (corrosion resistance, thermal expansion properties, etc.) are required. To satisfy these requirements, magnetic disks are manufactured by forming multiple thin films on a substrate material by sputtering, plating, coating, or the like.

FIG. 4 is a partial sectional view showing a conventional magnetic disk.
No. 5 [21] is a flowchart showing an example of conventional magnetic disk manufacturing step (2). The production of conventional magnetic disks (1) is as follows:
First, a substrate (2) made of, for example, aluminum alloy, glass, or plastic is machined to a predetermined degree of flatness, smoothness, and roughness. Next, as a base for forming a magnetic layer, a hardened layer (3
) to improve adhesion to the magnetic layer, prevent corrosion, and provide a clean and defect-free surface.Next, the surface of this hardened layer (3) is polished to a mirror finish by polishing, etc.6. Co-N1-P Metsuki, Co-
A magnetic layer (magnetic medium film) (4) is formed by Ni-Co-N1-Cr-rFe2oz sputtering or the like.

Next, a protection/lubrication layer (5) is formed to protect this important magnetic layer (4) and provide lubricity between the magnetic disk (1) and the head (not shown). In particular, for the long-term reliability of the magnetic disk (1), protection and
The formation of a lubricating film (5) is important, and methods such as forming a carbon sputtered film on a protective Cr sputtered film or applying an organic lubricant such as PEPE (perfluoropolyether) are used. Ta.

The conventional magnetic disk (1) is configured as described above,
In the method of forming the protective/lubricant film (5) by applying an organic lubricant, voids are likely to form and uniform application is difficult, resulting in problems such as poor yield. Furthermore, even when a carbon sputtered film is formed on a protective Cr sputtered film to form a protective/lubricant film (5), it is difficult to control the film quality uniformly, and the lubricity may not be sufficient, especially in areas where the film is thin. Problems have arisen, such as easy wear due to contact with the head, and poor separation of the head when the magnetic disk rotates.

[Problems to be solved by the invention] Since there is no established technology for forming a protective/lubricant film (5) on the magnetic disk (1) as described above, it is necessary to form a carbon sputtered film or use an organic lubricant. However, these methods had the problems of poor yield and poor lubricity.

This invention was made to solve these problems.
The object of the present invention is to obtain a magnetic disk that protects the magnetic layer, has excellent lubricity for the head, and has improved long-term reliability and yield.

[Means for Solving the Problems] A magnetic disk according to the present invention includes a substrate, a magnetic layer formed on the substrate, and particles of a highly wear-resistant substance formed on the magnetic layer inside. It is made up of a protective film in which is scattered, and a lubricating film formed on this protective film and having a smooth surface and self-lubricating properties.

[Function] In this invention, protection of the magnetic layer is achieved by a homogeneous wear-resistant protective film, and the wear resistance of the head is determined by the hardness of particles made of a highly wear-resistant substance scattered in the protective film. By improving the self-lubricating properties of the lubricating film itself on the surface of the head during rotation of the magnetic disk, the long-term reliability of the magnetic disk and the yield during manufacturing are improved.

[Example] FIG. 1 is a partial cross-sectional view showing an example of the present invention.
(2) to (4) are exactly the same as those in the conventional magnetic disk described above. A protective film (6) made of, for example, an amorphous carbon film is formed on the magnetic layer (4) of the magnetic disk (IA). This protective film (6) contains particles (
7) are scattered, thus improving the wear resistance for the head (not shown). A lubricating film (8) with a smooth surface is formed on the WIFK (6) and is made of a self-lubricating substance such as amorphous carbon or graphite. This lubrication 111*(8) improves the lubricity of the magnetic disk (IA), and at the same time improves head separation during rotation.

In the magnetic disk (IA) configured as described above,
For example, by using a thin film forming apparatus (9) as shown below, it is possible to form a protective film (6) made of a highly wear-resistant material such as amorphous carbon.

Fig. 2 is a schematic side sectional view of a thin film forming apparatus (9) using a laser, and Fig. 3 is a perspective view of the thin film forming apparatus shown in Fig. 2 (-parts are omitted). In these figures, an ultraviolet laser beam (11) such as an ArF excimer laser generated by an ultraviolet laser transmitter (10) is shaped into an appropriate energy density by a cylindrical telescope (12), and then divided into two by a partition wall (14a). Irradiation enters a box-shaped reaction chamber (14) partitioned into a box-shaped reaction chamber (14) through a window (13) on its negative side and a window (14) on the opposite side.
In the reaction chamber (14), a processed substrate (2a) on which a hardened layer (3) and a magnetic layer (4) are sequentially formed on the substrate (2) as in the conventional case exits the reaction chamber (14) from 3a).
) is held on the susceptor (15). This susceptor (15) is rotatably supported at the bottom of the reaction chamber (14) via a rotating shaft (15a), and is rotationally driven by a drive control device (16) via a transmission mechanism (not shown).

At the top of the reaction chamber (14) is an ECR (electron cyclotron resonance) plasma generator! (E), this ECR plasma generator fi (E) is arranged above the reaction chamber (14), and its lower end is connected to the reaction chamber (14).
) A cylindrical ECR plasma generation chamber (17) that opens into the interior.
and a microwave generation source (not shown) for generating microwaves (18) (for example, 2.45 Gllz);
An annular air-core coil (one) placed around the ECR plasma generation chamber (17) to generate a magnetic field.
It consists of A supply pipe (20) for introducing hydrogen (H2), which is a plasma source gas, is provided at the top of the ECR plasma generation chamber (17), and from this supply pipe (20) into the ECR plasma generation chamber (17). Hydrogen plasma ( 21) is generated.

In the reaction chamber (14), methane (
CH, ) (several tens of nuaHg), and this methane is filled with an ultraviolet laser beam (11) shaped by a cylindrical telescope (12) (for example, a peak output of 10 μm).
/cm”) is photodissociated by two-photon absorption.On the other hand,
Hydrogen ions are given an appropriate speed by a mesh electrode (22) for ion acceleration provided at the opening of the plasma generation chamber (17) to the reaction chamber (14), and are processed in the reaction chamber (14). It reaches the surface of the substrate (2a). In the initial process of film formation, these hydrogen ions are released onto the processed substrate (2a
), causing crystal distortion and facilitating the formation of nuclei for diamond crystal growth. In the process after nucleation, hydrogen ions have a strong etching effect when energy of several hundreds of eV is applied, and serve to suppress the growth of graphite crystals that occurs simultaneously with the growth of diamond crystals. Therefore, a modified diamond thin film containing less impurities such as graphite can be obtained as expected. That is, in the early stage of film formation, etching with hydrogen ions suppresses the growth of graphite crystals and promotes the growth of mainly diamond crystals, so that mainly diamond crystal particles are scattered in the smooth amorphous carbon film. Form a film. In the latter half of the film formation, the etching effect of hydrogen ions is weakened, and the film is formed so as to leave a highly lubricating graphite component.

Further, since the ECR plasma generator (E) can increase the plasma density by one order of magnitude or more than a normal plasma generator, it is possible to control these film forming processes at high speed and well. Furthermore, this film forming process can be performed without heating the processed substrate (2a) while maintaining it at approximately room temperature.

However, as mentioned above, the deposition gas atmosphere and plasma,
In the ionic atmosphere, it is several mmHg and 10 to 10 mmHg, respectively.
There is a large difference in the degree of vacuum, such as -'mmHg, and it is difficult to perform these simultaneously in one reaction chamber (14). For this reason, as shown in FIG. 2 and FIG.
4b) and a laser thin film forming chamber (14c), and a susceptor (15) is installed so as to span these reaction chambers.
A processed substrate (2a) is placed on top. The divided reaction chambers (14b) and (14c) are not completely independent, and there is a gap of several mm between the processed substrate (2a) and the partition wall (14a). By,
Plasma, ion reaction chamber (14b) and thin film formation chamber (14
c) can maintain the differential pressure with Further, the thin film forming chamber (14c) is provided with a supply port (23) for supplying a film forming gas such as methane (CH), and an exhaust pipe (24) for connecting to a vacuum pump (not shown). plasma,
The ion reaction chamber (14b) is also provided with a discharge pipe (25) for connection to a vacuum pump (not shown).

In this state, the susceptor (
15) is rotated by the drive control device (16), the surface of the processing substrate (2a) is alternately placed in an atmosphere where plasma and ions act and an atmosphere where thin film formation occurs.

That is, the processed substrate (2a) has crystal formation nuclei formed by hydrogen ions in the plasma and ion reaction chamber (14b).
) is connected to the thin film forming chamber (1) by the susceptor (15).
4c), where an amorphous carbon film is formed using methane gas dissociated by a laser.

Amorphous carbon film is coated on the surface of the processed substrate (2a).
After about 0 people have formed a film, the susceptor (15) is rotated to return a part of the processed substrate (2a) to the initial plasma and ion reaction chamber (14b), where hydrogen ions generate graphite that is generated at the same time as diamond crystal growth. Remove. In this way, the processing substrate (2) is rotated by the rotation of the susceptor (15).
Film formation (diamond crystal growth) and graphite removal are repeatedly performed on the surface of a) to obtain the desired yA quality, that is, a smooth amorphous carbon film with diamond crystal particles interspersed with it, and a wear-resistant crushed protective film ( 6) can be formed.

After that, the voltage applied to the mesh electrode (22) for ion acceleration is appropriately reduced to weaken the etching effect of hydrogen ions, and the outermost surface of the processed substrate (2a) is made of smooth amorphous carbon, graphite, etc. that does not contain diamond particles. A lubricating film (8) consisting of

In the above-mentioned embodiment, a thin film forming apparatus using an ultraviolet laser beam and an ECR plasma source as energy sources has been described. The magnetic disk protective film (6) and lubricating film (8) according to the present invention can also be applied to sliding parts that require lubricity. In addition, although the hardened layer (3) is formed in FIG. 1, it is not necessary to form this if desired.

[Effects of the Invention] As explained above, the present invention comprises a substrate, a magnetic layer formed on the substrate, and a protective layer formed on the magnetic layer with particles of a highly wear-resistant material interspersed therein. This film consists of a lubricating film formed on the protective crotch with a smooth surface and self-lubricating properties, which increases the hardness of the magnetic disk and improves the abrasion resistance of the head, and also improves the lubricity of the magnetic disk surface. Since the head separation during rotation is also improved, the long-term reliability and yield of the magnetic disk are improved.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention, FIG. 2 is a schematic side sectional view of a thin film forming apparatus used for manufacturing a magnetic disk according to an embodiment of the invention, and FIG. FIG. 4 is a partial cross-sectional view of a conventional magnetic disk.
FIG. 5 is a flowchart showing an example of a conventional magnetic disk manufacturing process. In the figure, (IA) is a magnetic disk, (2) is a substrate,
(2a) is a processed substrate, (3) is a hardened layer, (4) is a magnetic layer, (6) is a protective film, (7) is a diamond particle, (8)
is a lubricating film. In each figure, the same reference numerals indicate the same or corresponding parts. Agent Teru Sogado. ■ C%J Figure 3 1 only Figure 4 Figure 5 Procedural amendment 7F November 10, 1985 1.7 Office of the Chief Minister 1, Indication of the case 1988 Patent Application No. 155561 2, Title of the invention Magnetic disk 3, relationship to the amended person case Patent applicant address: 2-3 Marunouchi 2-chome, Chiyoma-ku, Tokyo Name (601) Mitsubishi Electric Corporation Representative Moriya Shiki 4, Agent address: Tokyo 4th floor, Marunouchi Building, 2-4-1 Marunouchi, Chiyoda-ku, Tokyo Telephone: (216) 5811 (Representative) Name (57)
87) Patent Attorney Doteru Soga & Contents of the amendment (revise the υ specification as shown).

Claims (4)

[Claims] (1) A substrate, a magnetic layer formed on this substrate, a protective film formed on this magnetic layer with particles of a highly wear-resistant substance scattered inside, and a surface formed on this protective film. 1. A magnetic disk comprising: a lubricating film that is smooth and has self-lubricating properties. (2) The magnetic disk according to claim 1, wherein the particles of the substance having high wear resistance are diamond particles. (3) The magnetic disk according to claim 1, wherein the protective film is an amorphous carbon film containing carbon as a main component. (4) The magnetic disk according to claim 1, wherein the lubricating film having self-lubricating properties is an amorphous carbon film or a graphite film that does not contain diamond particles.