JP2643783B2 - Magnetic disk substrate processing equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk substrate processing apparatus for preventing a magnetic head used in a contact start / stop type magnetic disk apparatus from sticking to a magnetic disk.

[0002]

2. Description of the Related Art In a contact start / stop type magnetic disk drive, the surface of a magnetic disk substrate which is a base of the magnetic disk medium is reduced in order to reduce the attraction between the magnetic head and the magnetic disk medium when the magnetic disk is stopped. Although a method of increasing the roughness is employed, if the surface roughness increases, the electromagnetic conversion characteristics in the data area deteriorate.

A magnetic disk medium (for example, Japanese Patent Application Laid-Open No. 54-23508) has been proposed in which the surface roughness of the contact start / stop area of the magnetic disk medium is made larger than that of the data area. The specific content is that, after precision finishing is performed by polishing, the surface roughness of the contact start / stop area is made larger than that of the data area by rough abrasive paper or abrasive cloth.

[0004]

However, since the contact start / stop area is actually removed by polishing, the contact start / stop area is provided on the medium layer 33 on the magnetic disk substrate 34 as shown in FIG. The entire contact start / stop region 32 becomes a small dent.

For this reason, when the magnetic head (not shown) crosses the contact start / stop area 32 and passes to the data area 34, the magnetic head tilts at the location of the minute dent and the floating becomes unstable. Therefore, there is a disadvantage that the medium layer 33 is damaged by collision.

According to the proposal of Japanese Patent Application Laid-Open No. 63-249933, after the entire surface of a magnetic disk substrate is rough-finished in advance, only the data area is precision-polished to reduce the surface roughness.

However, in this case, FIG.
As shown in (b), the contact start / stop area 42 provided in the medium layer 43 on the magnetic disk substrate 44 becomes a minute projection compared to the data area 41, and the magnetic head is used for high density recording. If the flying height of the magnetic head is further reduced, the magnetic head collides with the minute convex portion of the contact start / stop region 42, causing a defect that the medium layer 43 is damaged.

SUMMARY OF THE INVENTION An object of the present invention is to solve such a conventional problem, to prevent attraction between a magnetic head and a magnetic disk medium in a contact start / stop area of a magnetic disk, and to prevent a contact start / stop from occurring. It is an object of the present invention to provide a processing apparatus for processing a magnetic disk substrate realizing stable floating of a magnetic head in a stop region with high productivity.

[0009]

According to the present invention, there is provided an apparatus for processing a magnetic disk substrate, comprising: a drive shaft which rotates while supporting a magnetic disk substrate to be processed in a vertical direction; An abrasive spray nozzle for spraying abrasive grains opposite to both surfaces of the processed magnetic disk substrate; a container disposed below the drive shaft for immersing the processed magnetic disk substrate in a cleaning liquid; And an ultrasonic oscillator that emits ultrasonic waves in the cleaning liquid so as to oppose both surfaces of the magnetic disk substrate to be processed.

[0010]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a sectional view showing an embodiment of a magnetic disk substrate processing apparatus according to the present invention. Referring to FIG. 1, the magnetic disk substrate processing apparatus of the present invention includes a rotating shaft 11 that vertically supports a magnetic disk substrate 10, and immerses the magnetic disk substrate 10 below the rotating shaft 11 in a cleaning liquid 14. The container 15 is provided. Then, the cleaning liquid 14 is made to face both surfaces of the magnetic disk substrate 10.
Ultrasonic oscillators 16 and 17 are provided therein.

Next, as an example of processing a magnetic disk substrate, a magnetic disk substrate (surface roughness 0.01 μm ) 10 is about 1
While rotating at a rotation speed of 80 rpm, a particle diameter of 1 from the two injection nozzles 12 and 13 was applied to the surface of the magnetic disk substrate 10.
μm spray abrasive grains (alumina abrasive grains) 18 and 19 are applied at a pressure of 0.
Ultrasonic waves (20 kHz) were emitted from the ultrasonic oscillators 16 and 17 in the cleaning liquid (pure water) 14 at 5 kg / cm 2.

That is, by the abrasive grains 18 and 19 sprayed from the abrasive grain spray nozzles 12 and 13, an infinite number of point-like fine recesses are formed in the contact start / stop regions on both surfaces of the magnetic disk substrate 10, and the ultrasonic waves are formed. The abrasive particles attached to the surface of the magnetic disk substrate 10 are removed by utilizing the stirring phenomenon of the expansion / compression movement of the cleaning liquid 14 due to the above. Also,
During the processing, the formation of the fine dents and the removal of the attached abrasive grains are alternately repeated a plurality of times (for example, 30 times in a processing time of 10 seconds in the case of the present embodiment), and the plane of the data area and the point-like fine An infinite number of point-like fine depressions were formed in the contact start / stop / area of the magnetic disk substrate 10 so as to match the upper surfaces of the depressions.

In the case of this embodiment, the contact start
The diameter of the point-like fine depression formed in the stop region is 0.2 to 0.3 μm, and the depth is 0.04 to 0.05.
μm. As a result, the real contact area between the magnetic head and the magnetic disk medium contact start / stop area while the magnetic disk is stopped is reduced by the innumerable dot-like fine dents, and the adsorption static friction coefficient is 0.15 to 0.15.
0.20, and the adsorption static friction coefficient of the data area is 1.0 to
The value was significantly reduced as compared with 1.5.

Further, the data area surface and the top surface of the point-like fine recess are made to coincide with each other, and the contact start / stop /
Since a myriad of point-like fine depressions are formed in the area, when the magnetic head is levitated, its flying height is 0.05 μm.
And stably levitated. As a result, the magnetic disk substrate processing apparatus of the present invention was able to obtain a contact start / stop type magnetic disk substrate in a short time with high productivity.

[0016]

As described above, according to the present invention, in the contact start / stop zone of the magnetic disk, the attraction between the magnetic head and the magnetic disk medium is prevented, and the contact start / stop area is reduced. A processing device for processing a magnetic disk substrate that realizes stable magnetic head floating can be obtained.

[Brief description of the drawings]

FIG. 1 is a sectional view showing one embodiment of a magnetic disk substrate processing apparatus according to the present invention.

FIG. 2 is a plan view showing an example of a conventional contact start / stop type magnetic disk substrate.

FIG. 3 is a sectional view of FIG. 3;

[Explanation of symbols]

10, 34, 44 Magnetic disk substrate 11 Rotary axis 12, 13 Abrasive spray nozzle 14 Cleaning solution 15 Container 16, 17 Ultrasonic oscillator 18, 19 Abrasive abrasive 21, 31, 41 Data area 22, 32, 42 Contact start Stop area 33, 43 Medium layer

Claims (1)

(57) [Claims] 1. A drive shaft which rotates while supporting a magnetic disk substrate to be processed in a vertical direction, and abrasive grains are arranged above the drive shaft and abrasive grains are opposed to both surfaces of the magnetic disk substrate to be processed. An abrasive spray nozzle, a container disposed below the drive shaft for immersing the magnetic disk substrate to be processed in a cleaning liquid, and a container disposed in the container and forming the magnetic disk substrate in the cleaning liquid. An apparatus for processing a magnetic disk substrate, comprising: an ultrasonic oscillator that emits ultrasonic waves facing both surfaces.