JPS61261816A - Vertical magnetic recording medium - Google Patents

Abstract

PURPOSE:To improve durability by packing respectively the small holes of an anodic alloy oxidized film with a vertical magnetic anisotropic magnetic film and non-magnetic metal. CONSTITUTION:The surface of an Al substrate 11 is subjected to an anodic oxidation treatment to form an alumite layer 12 thereon to 20-30mum thickness. The non-magnetic metal 13 consisting of Ti, Cu, etc. is packed into the small hole groups (h) of 200-600Angstrom diameter of the alumite layer 12 into the bottom parts at about <=1mum from the surface. The vertical recording material of Fe, Ni, Co etc. having about 1mum film thickness is packed onto the non-magnetic metal 13 of the same holes (h). A barrier layer 15 consisting of a conductor is formed between the Al substrate 11 and the non-magnetic metal 13. The alumite layer 12 is preferably formed to 20-30mum thickness to improve the surface polishing accuracy and roughness. The recording density of the vertical density of the conventional medium and since the hardness of the medium is increased, the depression of the medium surface is obviated and the durability as the medium is consequently remarkably improved.

Description

Detailed Description of the Invention [Summary] This is a perpendicular magnetic recording medium, in which a group of small holes in a thick anodic oxide film is formed on the surface of an aluminum or aluminum alloy substrate, and a strong layer is formed at a position 0.2 to 3 μm from the surface. It is filled with a magnetic material and a non-magnetic metal below it, making it possible to improve durability.

[Industrial application field]

The present invention relates to improvements in perpendicular magnetic recording media, and more particularly to a new media structure with improved durability.

[Conventional technology]

As one of this type of perpendicular magnetic recording media, iron (F
e) A perpendicular magnetic recording medium filled with magnetic materials such as nickel (Ni), cobalt (Co), and their alloys (hereinafter referred to as perpendicular recording material) was published in Japanese Patent Publication No. 51-2156.
It is disclosed by No. 2.

This recording medium has advantages such as good perpendicular anisotropy and high density recording, and is suitable as a rigid magnetic disk.

[Problem that the invention seeks to solve]

In a perpendicular magnetic recording medium in which small holes in the alumite layer are filled with a perpendicular recording material, the thickness of the perpendicular recording material layer is limited to 1 to 2 μm at most, as a condition for writing data without lowering the recording density.

Therefore, the thickness of the hard alumite layer cannot exceed this value. With this thickness, sufficient hardness cannot be obtained and durability as a recording medium is poor.

By the way, generally speaking, a magnetic disk device has a magnetic head mounted on a magnetic disk rotating at several thousand revolutions.
Data is recorded and reproduced by floating at a height of μm. However, in this lever device, it has been confirmed that when the floating head randomly seeks in the radial direction of the disk, the head collides with the disk quite frequently.

Therefore, when the above-mentioned perpendicular magnetic recording medium is applied to such a magnetic disk device, there is a problem that the medium surface caves in due to the collision of the magnetic head, resulting in a head crack or a shock.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a perpendicular magnetic recording medium that has sufficient hardness to prevent collapse due to head collisions.

[Means for solving problems]

In the perpendicular magnetic recording medium of the present invention, as shown in FIG. 1, a large number of small holes in an alumite layer 12 formed on the surface of an aluminum or aluminum alloy substrate 1) are formed with a 0.0-.
A perpendicular recording material 13 is filled in the position up to 2 to 3 μm,
A non-magnetic metal 14 is filled up to the bottom.

[Effect]

Film thickness 0.2-3μm filled in small pores of alumite layer
The perpendicular recording material enables high-density recording, and the non-magnetic metal below the recording layer increases the hardness and durability of the perpendicular recording medium.

〔Example〕

FIG. 1 shows a cross-sectional structure of a perpendicular magnetic recording medium according to the present invention, in which 1) is an aluminum substrate, and 12 is a film with a thickness of 20 to 30 μm formed by anodizing the surface of the aluminum substrate.
m alumite layer 13 is about 1 μm from the surface of a group of small holes with a diameter of 200 to 600 in the alumite layer 12.
A non-magnetic metal such as titanium (Ti), copper (Cu), etc. is filled in the bottom of the hole below, and 14 is made of Pe, old, Co, etc., which is also filled in a small hole on top of the non-magnetic metal 13. It is a perpendicular recording material with a film thickness of about 1 μm. Further, 15 is a barrier layer of a conductor. Note that the thickness of the alumite layer 12 of 20 to 30 μm is the minimum value necessary for improving surface polishing accuracy and hardness.

In the perpendicular magnetic recording medium of the present invention, the recording density can be increased like the previous media, and since the hardness of the medium is increased, the surface of the medium does not cave in due to collision with a magnetic head. Therefore, durability as a medium is greatly improved.

Next, a method for manufacturing the above perpendicular magnetic recording medium will be briefly explained.

First, the surface of the aluminum substrate 1) with a thickness of 4fi is 20~30μ
mAnodic oxidation treatment is performed to form a relatively thick alumite layer 12. Figure 2 shows the cross-sectional structure of this alumite layer 12, which has a structure in which countless fine hexagonal layers with a width of about 0.1 μm are lined up tightly in a honeycomb shape. with a diameter of 2 at the center of each hexagonal layer.
There are very small holes of 00 to 600 people.

Next, this aluminum substrate 1) is immersed in an electrolytic solution in which a salt of a non-magnetic metal such as Ti or Cu is dissolved, and electrolytic treatment is performed using the aluminum substrate side as a cathode, and the non-magnetic metal is poured into the small holes of the alumite layer 12. Deposit about 1 μm below the surface. Subsequently, the aluminum substrate 1) is immersed in an electrolytic solution in which a salt of a ferromagnetic metal such as Fe or ferromagnetic metal is dissolved, and subjected to the same electrolytic treatment to deposit the ferromagnetic metal up to the surface of the small pores.

Thereafter, the aluminum surface is polished to complete the desired perpendicular magnetic recording medium.

〔effect〕

As is clear from the above description, the magnetic recording medium of the present invention, in which the small holes of the alumite layer on the surface of aluminum or an aluminum substrate are filled with nonmagnetic metal and ferromagnetic metal, can achieve high-density recording and reproduction. In addition, it is possible to significantly improve the durability of the medium and extend its life.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part showing the structure of a perpendicular magnetic recording medium according to the present invention, and FIG. 2 is a partially sectional perspective view schematically showing the alumite layer of FIG. 1. In each figure, 1) is an aluminum substrate, 12 is an anodized film, 13 is a nonmagnetic metal, 14 is a perpendicular magnetic anisotropic material, 15 is a barrier layer, and h is a small hole.

Claims (2)

[Claims] (1) In a magnetic recording medium configuration in which a large number of small holes in an anodized film formed by anodizing the surface of aluminum or an aluminum alloy are filled with a magnetic material, the small holes in the anodic oxide film (12) are filled with a magnetic material. hole (h) from the surface
．． A perpendicular magnetic anisotropic magnetic material (13) made of iron, cobalt, nickel, one of their alloys, or an alloy of these and a non-magnetic metal up to a position of 2 to 3 μm, and a non-magnetic metal below it. A perpendicular magnetic recording medium characterized in that it is filled with (14). (2) The depth of the small pores (h) of the anodic oxide coating (12) is 20 to 30 μm, and the perpendicular magnetic anisotropic magnetic material (13) is filled about 1 μm below the surface of the small pores. A perpendicular magnetic recording medium according to claim (1).