JPH05189759A - Magnetic disk device - Google Patents

Abstract

PURPOSE:To provide the magnetic disk device having the good floating stability of a magnetic head for obtaining a magnetic disk having high recording density. CONSTITUTION:A working head 2 rotating around the axis of rotation parallel with the axis of rotation of the magnetic disk 1 is movably supported toward the axis of rotation of the magnetic disk 1. The magnetic disk is floated by the dynamic pressure generated by the rotation of the working head 2. The atmosphere thereof is formed of working fluid contg. fine abrasive grains. The projecting parts of the magnetic disk 1 are selectively worked to decrease the rotational surface wave of the magnetic disk 1 to <=1mum. The magnetic disk device is so constituted as the fluctuation in the spacing between the magnetic head and the magnetic disk 1 is decreased to <=0.01mum. The errors at the time of recording and reproducing are eliminated and the head crush is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk of an external storage device for an electronic computer and a device therefor, and in particular, a magnetic head is levitated on a rotating magnetic disk at a low flying height to enable high-density recording / reproduction. And a method of manufacturing the same, and a magnetic disk device using the magnetic disk.

[0002]

2. Description of the Related Art In a conventional magnetic disk device, a magnetic head is levitated by about 0.1 μm from the surface of the magnetic disk to record and reproduce signals. In order to increase the recording density of the magnetic disk device, the magnetic head and the surface of the magnetic disk are increased. It is necessary to make the gap between and constant. In this magnetic disk device, the shape of the magnetic disk is greatly related to the method of processing the magnetic disk substrate and the method of fixing the magnetic disk to the rotating shaft of the magnetic disk device.

A conventional method of processing a magnetic disk is, as described in Japanese Patent Laid-Open No. 63-109975, a magnetic disk sandwiched between opposing upper and lower surface plates having a polishing pad and a space between the polishing pad and the magnetic disk. The magnetic disk was processed by relative sliding between the polishing surface plate and the magnetic disk while supplying the polishing liquid.

[0004]

However, the conventional magnetic disk device does not take into consideration the fluctuation of the flying height of the magnetic head due to the surface wobbling of the magnetic disk, and the magnetic head cannot follow the surface of the magnetic disk to record. In some cases, there was a mistake in reproduction, or in the worst case, the magnetic head collided with the magnetic disk, resulting in a head crash. Also, no consideration was given to changes in the shape of the magnetic disk when the magnetic disk was incorporated into the rotating shaft of the magnetic disk device.
When the magnetic disk was incorporated, the shape of the magnetic disk changed, and the above-described recording / reproducing error sometimes occurred.

The shape of the magnetic disk that determines the surface wobbling of the magnetic disk is greatly related to the processing method thereof, and in the conventional processing method, consideration is given to the surface wobbling of the magnetic disk surface that occurs when the magnetic disk is rotated. However, the relatively soft polishing pad follows the undulations of a relatively long period on the surface of the magnetic disk surface, and the undulations cannot be processed. Therefore, as described above, the flying height of the magnetic head fluctuates, which causes a recording / reproducing error or a head crash.

[0006]

In a magnetic disk device, a magnetic head is levitated above a rotating magnetic disk for recording / reproducing, and in order to improve recording density, the magnetic head is almost in contact with the magnetic disk. It may be recorded and reproduced. The magnetic head used for recording / reproducing is supported by a spring in the direction of the rotation axis of the magnetic disk, and floats or is in contact with the magnetic disk at fixed intervals while following the wobbling of the rotation surface of the magnetic disk and the wavy shape having a relatively long period. In the present invention, since the rotational surface runout of the magnetic disk is set to 1 μm or less, the magnetic head supported by the spring so as to be movable in the rotation axis direction of the magnetic disk can follow the surface of the magnetic disk with a flying height variation of 0.01 μm or less. ..

Further, in the magnetic disk processing method of the present invention, since the processing head has the same mechanism as the support system of the magnetic head used in the actual magnetic disk apparatus, it does not affect the recording / reproducing of the magnetic disk apparatus. The processing head follows the relatively small surface wobbling or waviness of the magnetic disk, and can process the raised portion of the magnetic disk that causes fluctuations in the gap between the magnetic head and the magnetic disk. That is,
Since the surface of the magnetic disk is processed by the processing head having good followability, the surface of the magnetic disk is wobbled and waviness is applied with a substantially constant pressure, and polishing unevenness does not occur. Further, the convex portion of the magnetic disk where the pressing force changes rapidly increases the pressing force, and only the convex portion on the surface of the magnetic disk can be selectively processed. Further, since the machining head is rotated, the relative speed is increased and stable non-contact pressurization of the floating gap can be performed, so that problems such as scratches due to chip entrainment do not occur.

[0008]

In the magnetic disk device according to the present invention, since the gap between the magnetic disk and the magnetic head is constant, recording / reproducing errors do not occur. Moreover, the magnetic head and the magnetic disk do not come into contact with each other in a shock, and an accident such as a head crash does not occur.

Further, according to the method of processing a magnetic disk of the present invention, in the atmosphere filled with the processing liquid in which fine abrasive grains are mixed, a fine grinding is performed by a processing head which floats on the surface of the magnetic disk with a constant gap. The particles are pressed and slide on the surface of the magnetic disk to remove the protrusions on the surface of the magnetic disk. The gap between the magnetic disk and the processing head is determined by the relative speed between the magnetic disk and the processing head and the load on the processing head. Also, although the rotating magnetic disk has surface waviness, waviness, etc., since the processing head can move in the floating direction, a constant gap is maintained, and only the convex portions of the shape that rises relatively rapidly are processed by the abrasive grains. ..

[0010]

Embodiments of the present invention will be described with reference to the drawings.
1A and 1B are model diagrams showing the relationship between a magnetic head and a magnetic disk of a magnetic disk device. FIG. 1A is a conventional magnetic disk device, and FIG. 1B is a model diagram of the magnetic disk device of the present invention. FIG. 2 shows an inner diameter of 40 mm, an outer diameter of 130 mm, and a thickness of 1.9.
FIGS. 3 to 5 are explanatory views of the present invention, showing changes in the gap between the magnetic head and the magnetic disk (fluctuation of the flying height) with respect to runout of the rotational surface of the magnetic disk of mm. FIG. 6 shows an example of a conventional processing method.

The magnetic disk apparatus of the present invention uses a magnetic disk having a high shape accuracy by the following processing method, and further, when the magnetic disk is incorporated into the rotary drive shaft of the magnetic disk apparatus, the rotational surface runout of the magnetic disk is measured. While 1
Assemble to less than μm. The relationship between the surface fluctuation of the magnetic disk and the fluctuation of the flying height of the magnetic head is as follows. As a result of an experiment conducted in advance, by setting the surface fluctuation of the magnetic disk to 1 μm or less, the fluctuation of the flying height of the head is 0.01 μm or less. Therefore, the head flying height change of the magnetic disk device of the present invention is 0.01 μm or less.

In the processing method of the present invention, as shown in FIGS. 3 to 5, a mechanism (not shown) for rotating the magnetic disk 1 and a mechanism (not shown) for moving the processing head 2 in the radial direction of the magnetic disk 1. No.) and a mechanism (not shown) for rotating the processing head 2 so that the processing head 2 can freely move in the rotation axis direction of the magnetic disk 1.

The magnetic disk 1 to be processed is in the processing liquid tank 9. After mounting the magnetic disk 1 on the processing apparatus, the processing head 2 is installed on the surface of the magnetic disk 1 to rotate the magnetic disk 1. At the start, the processing head 2 is rotated to float on the surface of the magnetic disk 1. The peripheral speed difference between the inner and outer peripheries of the magnetic disk 1 can be neglected by making the rotation speed of the processing head 2 sufficiently large. The convex portions 4 on the surface of the magnetic disk 1 are removed by the fine abrasive grains 3 between the flying processing head 2 and the magnetic disk 1, and the target highly accurate magnetic disk 1 is obtained.

In the present invention, an inner diameter of 40 mm, an outer diameter of 130 mm, and a thickness of about 10 μm, which are generally used as a substrate of a magnetic disk, are Ni-P plated and then double-side polished to a surface roughness Ra of 2 to 3 nm. A 1.9 mm aluminum alloy magnetic disk substrate was rotated at 500 revolutions per minute in a water-soluble processing liquid containing silicon oxide to form a dynamic pressure generating surface on the surface with an outer diameter of 15 mm. The tool was placed on the surface of the magnetic disk at 100 gf per square centimeter and 1500 revolutions per minute and processed for 1 minute. Further, a magnetic disk device was constructed using the magnetic disk after this processing. This magnetic disk device
The surface runout of the magnetic disk was assembled using a non-contact displacement meter while measuring the runout of the rotary surface so that the runout of the rotary surface was 1 μm or less.

In this magnetic disk device, since the fluctuation of the flying height of the magnetic head was 0.01 μm or less, there was no recording / reproducing error and no head crash occurred.

As a comparative example, the conventional processing method shown in FIG. 6 is used in comparison with the above-mentioned examples, and the above Ni--P is used.
The plated aluminum alloy substrate is used as a working liquid to form 0.1
Using colloidal silica of μm, processing was carried out for 30 seconds at a platen rotation speed of 50 rpm, and the magnetic disk device was incorporated with the rotational surface runout of 1 μm or less as described above. The surface of the magnetic disk produced by this processing method was uneven, and the magnetic head did not fly.

[0017]

According to the present invention, since the convex portions on the surface of the magnetic disk are removed by the fine abrasive grains pressed by the non-contact processing tool, the fluctuation in the flying height of the magnetic head is reduced to 0.
It is possible to efficiently obtain a highly accurate magnetic disk of 01 μm or less. Further, since the flying height of the magnetic head can be made low and stable, it is possible to obtain a magnetic disk capable of achieving high recording density.

[Brief description of drawings]

FIG. 1 is a diagram showing a flying model of a magnetic head of a magnetic disk device.

FIG. 2 is a diagram showing a relationship between surface wobbling of a magnetic disk and fluctuation of a flying height of a head.

FIG. 3 is a diagram showing a processing method of the present invention.

FIG. 4 is an explanatory diagram of a processing principle of the present invention.

FIG. 5 is a schematic view of a processing method of the present invention.

FIG. 6 is a diagram showing an example of a conventional processing method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Magnetic disk, 2 ... Processing head, 3 ... Processing liquid (abrasive grains), 4 ... Convex part, 5 ... Burnishing head, 6 ... Contact roller, 7 ... Polishing tape, 8 ... Pressurizing force, 9 ... Processing liquid tank 10 ... Polishing cloth, 11 ... Leaf spring, 12 ... Extension spring, 13 ... Key, 14 ... Tool rotating shaft, 15 ... Housing, 16 ... Dynamic pressure generating surface.

Claims (1)

[Claims] 1. A flying slider which is movable in a rotating direction of a magnetic disk and in a radial direction of the magnetic disk in a working liquid containing fine abrasive grains and which rotates about an axis parallel to the rotating axis of the magnetic disk. The processing head that has been arranged is placed on the magnetic disk, and the processing head is levitated on the surface of the magnetic disk with a constant gap by the buoyancy generated by the relative movement of the magnetic disk and the processing head, and A magnetic disk that has a flatness of 0.1 μm or less by selectively processing convex portions on the surface of the magnetic disk with fine abrasive grains pressed by a small load, and the magnetic disk while measuring the surface runout of the magnetic disk. The gap between the magnetic head and the magnetic disk due to the rotational surface wobbling of the magnetic disk is set by incorporating it in the disk device and setting the surface wobbling of the magnetic disk within the magnetic disk device to 1 μm or less. Variation (floating amount variation) between 0.01
A magnetic disk device characterized by having a thickness of less than μm.