JPS626438A - Magnetic disk - Google Patents

Abstract

PURPOSE:To reduce the floating variable of a head by forming the sectional shape of a disk board in the radius direction from an inner peripheral part to an outer peripheral part as a convex shape. CONSTITUTION:The sectional shape of an absorbing surface 4a of a vacuum chuck 2 is formed as a smooth curve. A material 1 is adsorbed along the curve and when a slash part 8 is cut off by a cutting byte 3 so the surface of the material 1 is made plane and then the material 1 is removed from the adsorbing surface 4a, the material 1 is returned to the original state on the basis of the rigidity of the material, an unworked surface 1a is plane and the worked surface 1b is made a curved surface transferred from the shape of the adsorbing surface 4a. Then, the worked surface 1b is adsorbed to an adsorbing surface 4b consisting of a curved surface having curvature smaller than that of the adsorbing surface 4a, cut off so that the adsorbed surface is made plane and then the material 1 is removed from the adsorbing surface 4b, a disk base plate 11 can be completed. Consequently, the floating variable of the magnetic head can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a Qi-magnetic disk, and particularly to a magnetic disk suitable for improving electromagnetic characteristics.

[Background of the invention]

Conventionally, it is well known that lowering the flying height of the magnetic nod as a method of improving the electromagnetic characteristics of a magnetic disk is impossible, and many inventions have been made to avoid using it at a low flying height.11. ing. Also related to magnetic disks (Japanese Patent Laid-Open No. 57-
There is a method of changing the thickness of the magnetic film as described in No. 74851. However, this was an attempt to equalize the four magnetic characteristics of the inner and outer circumferences of the magnetic disk, and no consideration was given to the adverse effects caused by changing the film thickness.

[Purpose of the invention]

An object of the present invention is to provide a magnetic disk that is effective in improving electromagnetic characteristics by reducing the flying height of the read/write section of a magnetic head without changing the thickness of the magnetic film.

[Summary of the invention]

A feature of the present invention is that the radial cross-sectional shape of the disk substrate from the inner circumference to the outer circumference has a smooth convex shape. This makes it possible to reduce the flying height of the head, thereby improving electromagnetic characteristics.

[Embodiments of the invention]

An embodiment of the present invention will be described below based on the drawings. FIG. 1 is a diagram showing a method for processing a disk substrate, in which a substrate (hereinafter referred to as the raw material) before processing is attracted to a vacuum chuck 2 of a processing lathe and rotated in the direction of arrow 9, and a cutting tool is used. 3 in the direction of arrow 10, one side is cut.

After that, the opposite side is cut in the same way to complete the substrate, and in the next step a magnetic film is formed to form a magnetic disk.

FIG. 2 is a cross-sectional view showing in detail the process of processing a disk substrate of a magnetic disk according to the present invention. (a)
As shown in the figure, the suction surface 4a of the KX empty chuck 2 has a smooth cross-sectional shape. The material 1 is adsorbed following this curve, and after cutting the diagonally shaded part 8 to form a straight line with the cutting tool 3, the material 1 is removed from the adsorption surface 4a (A).
As shown in , due to the rigidity of the material, the material 1 returns to its original state, the unprocessed surface 1α becomes a straight line, and the processed surface 1b becomes the suction surface 4a.
The shape is transferred and becomes a smooth curve. Next toj
As shown in (d), when the processing surface 1b is adsorbed to the adsorption surface 4b which has a curved line with a smaller curvature than the adsorption surface 4α, cut into a straight line, and removed from the adsorption surface 4b, a disk substrate 11 as shown in (d) is obtained. is completed. The shape of the disk substrate may be as shown in FIG. A magnetic film is formed on the surface of a shaped substrate to create a magnetic disk.

FIG. 4 is a diagram showing the effect of this embodiment, showing the same magnetic head H.
This is a state in which the magnetic disk 12 is levitated on the conventional magnetic disk 12 and the magnetic disk 12 according to this embodiment with a flying height of 0.4 μm. In the conventional case, as shown in +tL), the slider s5, which has a floating holder, and the center rail part 6, which has a read/write holder, are at the same height Hjl+=0.4 am from the magnetic disk surface 7.
In Although.

In this embodiment, as shown in U), the slider section 5 has Hp+=
0.4μm, center rail part 6 has HIz=0.3a
m, and is expected to have the effect of lowering the flying height.

The results of actually measuring the electromagnetic characteristics in this state are shown in FIG. The vertical axis shows output and resolution, and the horizontal axis shows disk radius, and it can be seen that the magnetic disk according to this example is excellent. Figure 6 shows the relationship between output and resolution, and it is clear that increasing the thickness of the magnetic film in an attempt to unnecessarily improve the output degrades the resolution characteristics, and the effectiveness of this example will continue to be proven. Ru.

[The young fruits of invention]

According to the present invention, by changing the thickness of the disk substrate, the flying height of the magnetic head can be reduced, and since there is no need to change the thickness of the magnetic film, there is no need to change the thickness of the magnetic film, so there is no need to change the thickness of the magnetic film. A magnetic disk with excellent resolution characteristics can be provided.

[Brief explanation of drawings]

FIG. 1 is a diagram for explaining a method for processing a disk substrate, FIG. 2 is a diagram for explaining a method for processing a disk substrate according to one embodiment of the present invention, and FIG. 3 is a diagram for explaining a method for processing a disk substrate according to another embodiment. FIG. 4 is a cross-sectional view showing the shape of the disk substrate, FIG.
This figure is a graph showing the electromagnetic characteristics of the magnetic disk obtained according to the present invention, and FIG. 6 is a graph showing that the resolution characteristics deteriorate by changing the thickness of the magnetic film. 1...Material 2...Vacuum chuck 6
...cutting pie) 4a...-adsorption surface 4b.
...Adsorption surface 5...Slider part 6...Center rail part 7...Magnetic disk surface 8...Diagonal line section 11 indicating cutting allowance...Disk substrate 1cL...Unprocessed surface 1b... - Machining surface 12...Magnetic disk.

Claims (1)

[Claims] In a magnetic disk consisting of a non-magnetic disk substrate and a magnetic film formed on the disk substrate, the cross-sectional shape in the radial direction from the inner circumference to the outer circumference of the substrate forms a smooth convex shape. A magnetic disk featuring