JPS61148686A - Magnetic disk medium - Google Patents

Abstract

PURPOSE:To prevent the damage of the titled magnetic disk medium made of glass by the contact of a spacer ring by providing a comparatively soft protective film to the contact region of the spacer ring on the periphery on the front and the rear surface along a central circular hole. CONSTITUTION:A protective film 4 consisting of a comparatively soft metal or a resin, etc. is furnished to the contact region of a spacer ring on the periphery on the front and the rear surface along a central circular hole 3 of a magnetic disk medium 1. A film of a comparatively soft metal consisting of copper Cu, gold Au, tin Sn, lead Pb, etc. is selectively coated by sputtering or plating, etc. to form the protective film 4, or a film of a resin such as an epoxy resin, an acrylic resin, polycarbonate, a silicone resin, etc. is selectively coated by spraying or coating, etc. to form the film 4.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic disk medium used in a magnetic disk device, and particularly to a reinforcing structure for a glass magnetic disk medium.

In recent years, magnetic disk devices have been increasing their recording density and capacity, and in order to improve the recording density of magnetic disk media, for example, a continuous sputtering method or the like is applied to the surface of a disk substrate made of aluminum or an aluminum alloy. Svanta magnetic disk media having a structure coated with a continuous magnetic thin film having stronger mechanical strength and superior magnetic properties than a deposited film are being put into practical use.

However, as such high-density recording is carried out, improvements in the smoothness and mechanical hardness of the disk substrate surface are required.

(Prior Art) In order to meet the above requirements, disk substrates made of aluminum or aluminum alloy have their own limitations in terms of materials, and instead of these disk substrates, it is possible to Attempts have been made to use glass disk substrates that can relatively easily obtain a smooth surface.

[Problem that the invention attempts to solve]

However, as for the above-mentioned glass disk substrate,
Although the glass member itself has considerable hardness and strength, it inherently has low viscosity and is brittle, so it must be handled with great care, especially for magnetic materials constructed using such glass disk substrates. When the disk media are attached to the spindle hub via spacer rings, if a metal spacer ring or the like is brought into direct contact with the glass disk substrate surface of each magnetic disk medium, the contact surface is likely to be scratched. However, depending on the degree of damage, damage may occur due to this.

Means for Solving Problem C] The above problem is that in a magnetic disk medium whose substrate member is made of glass, relatively soft This problem is solved by the magnetic disk medium according to the present invention, which has a structure in which a protective film made of metal or resin is provided.

(Function) That is, by providing a protective film made of relatively soft metal or resin on the spacer ring contact area on the circumferential surface along the central circular hole of the glass magnetic disk medium, the magnetic When a disk medium is attached to the spindle hub mechanism via a metal spacer ring, the spacer ring no longer comes into direct contact with the glass disk substrate surface of the magnetic disk medium, preventing damage to the corresponding substrate surface. It becomes possible to do so.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a schematic plan view showing the structure of an embodiment of the magnetic disk medium according to the present invention, and FIG.
'It is a sectional view taken along the cutting line.

In both of these figures, 1 is a magnetic disk medium in which a magnetic thin film (not shown) is adhered to a glass disk substrate 2, and spacer rings are in contact with the front and back circumferential surfaces of the magnetic disk medium 1 along the central circular hole 3. As shown in the figure, a protective film 4 made of relatively soft metal, resin, or the like is provided in the region.

In addition, the above-mentioned deposit ¥1M4 includes copper (Cu), gold (A
u).

A relatively soft metal film made of tin (Sn), lead (Pb), etc. is selectively deposited by sputtering or plating, or epoxy resin, acrylic resin, polycarbonate, silicone resin, etc. It can be formed by selectively depositing a resin film by a spraying method, a coating method, or the like.

Further, the protective film 4 may be deposited partially on the spacer ring abutting area of the glass magnetic disk medium 1, as shown in FIG.

By providing the protective film 4 in the spacer ring contact area of the glass magnetic disk medium 1 in this way,
When a plurality of the magnetic disk media 1 are attached to the spindle hub mechanism via a metal spacer ring using screws or the like, the spacer ring is attached to the glass disk substrate 2 surface of the magnetic disk medium 1 as described above. Soft protection lol
Since the contact is made via LIII, there is no risk of damage to the surface of the contact substrate.

〔Effect of the invention〕

As is clear from the above description, according to the configuration of the magnetic disk medium according to the present invention, when the glass magnetic disk medium is attached to the spindle hub mechanism via the metal spacer ring, the spacer ring Damage to the glass magnetic disk medium due to contact can be prevented by the protective film, and the reliability of the glass magnetic disk medium and, by extension, the magnetic disk device that uses it is significantly improved.

[Brief explanation of drawings]

FIG. 1 is a schematic plan view showing the structure of an embodiment of a magnetic disk medium according to the present invention, FIG. 2 is a sectional view taken along the cutting line nn' shown in FIG. 1, and FIG. FIG. 3 is a schematic plan view showing the structure of another embodiment of such a magnetic disk medium.

Claims (1)

[Claims] In a magnetic disk medium whose substrate member is made of glass,
A magnetic disk medium characterized in that a protective film made of relatively soft metal or resin is provided on the spacer ring abutting areas of the front and back peripheral surfaces along the central circular hole of the magnetic disk medium.