JPH1027338A - Magnetic disk and magnetic disk device using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost magnetic disk and a compact and low-cost magnetic disk device using the same. SOLUTION: A magnetic disk device 30 includes a non-magnetic substrate made of a synthetic resin and a magnetic film forming surface 3 provided in one surface of the non-magnetic substrate, and the magnetic film forming surface 3 includes a magnetic disk 1 having recessed surface to have a radius of curvature of roughly 30μm or more, a head slider 36 floating on the magnetic film forming surface 3 by a height of 50nm or less and a magnetic head loaded in the head slider 36. The magnetic disk device 30 includes the magnetic film forming surface 3 formed in one surface of the non-magnetic substrate, the low-cost of magnetic disk 1 in which the condition for forming the non-magnetic substrate is relaxed is used and, thus the number of parts is reduced for the entire device and the device is reduced in size and cost.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a magnetic disk on which data information is recorded and reproduced by a magnetic head mounted on a flying head slider, and a magnetic disk device using the magnetic disk.

[0002]

2. Description of the Related Art For example, in a computer system, a hard magnetic disk device is provided as a magnetic disk device. This magnetic disk device has the advantages that the storage capacity of the magnetic disk housed is larger than that of a normal floppy magnetic disk device and the reading speed is faster. Further, the magnetic disk device has an advantage that the reading speed is higher than that of the magneto-optical disk device. Therefore, in recent computer systems, the use of magnetic disk drives has become widespread, and on the other hand, there has been a strong demand for lower prices for magnetic disks and magnetic disk drives.

However, since the magnetic disk drive uses aluminum, glass or the like as the substrate material of the magnetic disk, the cost of the disk substrate material is reduced in terms of the cost of the substrate material and the manufacturing method such as polishing. Therefore, there is a limit in reducing the price of the entire magnetic disk device. Therefore, recently, the use of inexpensive and easily moldable synthetic resin as a basic material of a disk substrate of a magnetic disk has been attempted to reduce the cost of the magnetic disk and improve mass productivity.

[0004]

However, the synthetic resin has a property that the degree of shape change due to heat is greater than that of the above-mentioned aluminum, glass and the like. Therefore, when a synthetic resin is used as the basic material of the disk substrate, the magnetic disk has a problem that eccentricity or the like due to thermal deformation is more likely to occur as compared with the above-described disk substrate made of aluminum, glass or the like. Therefore, in order to prevent the occurrence of such thermal deformation, strict molding conditions are imposed on the shape of the magnetic disk when the disk substrate is formed of a synthetic resin.

Further, a magnetic disk made of a synthetic resin is liable to cause so-called sink marks in which a central portion of the disk substrate is dented.
Since the surface tends to be concave, there is a problem that the yield is deteriorated under severe molding conditions, which hinders cost reduction.

In general, a magnetic disk using a disk substrate made of a synthetic resin as a basic material has magnetic films formed on both surfaces of the disk substrate in order to secure storage capacity, and information is recorded on and reproduced from the magnetic films on both surfaces. Was adopted. However, in such a magnetic disk drive using a double-sided magnetic film type magnetic disk, it is necessary to provide a plurality of magnetic heads for recording and / or reproduction and a plurality of head sliders to which the magnetic heads are attached. Therefore, the number of parts increases, and the number of steps for assembling the magnetic head and the like increases. Therefore, in a magnetic disk drive using a double-sided magnetic film type magnetic disk, the structure and assembly process of the entire device become complicated. As a result, the magnetic disk device still has a problem in promoting price reduction even when a magnetic disk using a synthetic resin as a basic material is used.

[0007] Further, the magnetic disk drive is strongly required not only for the above-mentioned cost reduction, but also for a reduction in the size of the drive, particularly, a reduction in the thickness of the entire drive even if it is as thin as 1 mm. However, when a magnetic disk device of a double-sided magnetic film type is used, the number of components is increased and the structure of the entire device becomes complicated as described above, so that it is difficult to promote the thinning of the entire device. There is a problem that occurs.

SUMMARY OF THE INVENTION An object of the present invention is to provide a magnetic disk which can be manufactured at low cost and a magnetic disk device which uses this magnetic disk and which can be reduced in size and cost in order to solve the above-mentioned conventional problems. And

[0009]

A magnetic disk according to the present invention that has achieved the above object has a non-magnetic substrate formed of a synthetic resin, and is formed on one side of the non-magnetic substrate and records data information and the like. The magnetic film forming surface is a concave surface having a radius of curvature of about 30 meters or more.

The yield of the magnetic disk is improved by forming a magnetic film on one surface of the non-magnetic substrate, thereby streamlining the process of forming the magnetic film, and relaxing the conditions for forming the non-magnetic substrate. And cost can be reduced as a whole.

According to another aspect of the present invention, there is provided a magnetic disk drive comprising: a non-magnetic substrate formed of a synthetic resin having a magnetic film forming surface on which data information and the like are recorded on one surface; A magnetic disk having a concave surface with a radius of curvature of about 30 meters or more, and a recording and / or reproduction of data information or the like, which is levitated at a height of 50 nm or less with respect to a magnetic film forming surface of the magnetic disk. And a head slider on which a magnetic head is mounted.

The magnetic disk device uses a low-cost magnetic disk in which a magnetic film forming surface is formed on one surface of a non-magnetic substrate and molding conditions of the non-magnetic substrate are relaxed. The number of components can be reduced as a whole of the magnetic disk device, and the size and cost of the magnetic disk device can be reduced.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG.
The magnetic disk 1 has a recording surface 3 on one surface of a non-magnetic disk substrate 2 made of a thin disk-shaped synthetic resin, and a magnetic layer 12 described later is formed on the recording surface 3. . The surface of the magnetic disk 1 opposite to the recording surface 3 is a non-recording surface 4 on which the synthetic resin is exposed.
Further, the magnetic disk 1 has a center hole 5 formed in the center of the disk substrate 2. This magnetic disk 1
The outer diameter is 65 mm, the inner diameter of the center hole 5 is 20 mm, and the thickness is 1.2 mm. A recording area forming part 6 for data information and the like on the recording surface 3 and an inner peripheral side of the recording area forming part 6 Are formed, and a landing section 8 located on the outer peripheral side of the recording area forming section 6 is formed.

The disk substrate 2 is manufactured by an injection molding method using a thermoplastic synthetic resin as a material, similarly to the method of manufacturing a magneto-optical disk. The disc substrate 2 is made of, for example, a transparent polycarbonate resin, polyolefin resin, or the like as a material resin.

As shown in FIGS. 1 to 3, the magnetic disk 1 has a predetermined concave / convex pattern 9 formed on a recording area forming portion 6 of a disk substrate 2 made of a synthetic resin as described above. It has a layer structure in which the magnetic layer 12 is formed. The concavo-convex pattern 9 on the surface of the disk substrate 2 is formed by attaching a stamper (not shown) manufactured by using the same mastering technique as that for manufacturing a magneto-optical disc to a predetermined molding die and transferring the concavo-convex pattern of the stamper. Is done.

The uneven pattern 9 formed on the surface of the disk substrate 2 includes, as shown in FIGS. 1 and 2, a data area forming section 10 in which an area for actually recording and reproducing data is formed, and an address and recording area. A servo mark forming section 11 for forming a servo mark for controlling (tracking) the position in the track.

The data area forming section 10 includes the magnetic layer 1
2 is formed of a recording track forming portion 13 and a guard band forming portion 14 which become a recording track and a guard band when formed. The recording track forming section 13 has a convex shape, and the guard band forming section 14 has a concave shape.

On the other hand, the servo mark forming section 11 includes:
When the magnetic layer 12 is formed, an address mark, a fine mark, a burst, and an address mark forming unit 15 and a fine mark forming unit 16 serving as a header, respectively.
A burst mark forming section 17 and a header mark forming section 18 are formed. The servo mark forming section 11 is also provided with irregularities corresponding to address marks, fine marks, bursts, and headers.

In the magnetic disk 1, the servo information is recorded on each disk by using a servo signal recording device (not shown) since the servo mark forming unit 11 is provided integrally when the disk substrate 2 is formed in advance. Since there is no need to perform the above, the mass productivity can be improved.

As shown in FIG. 3A, a magnetic layer 12 is formed uniformly on the disk substrate 2 constructed as described above. The section has a substantially square wave shape corresponding to the pattern 9. The magnetic film that forms the magnetic layer 12 is formed by using a sputtering method, an evaporation method, or the like. This magnetic layer 1
As the magnetic material constituting 2, a cobalt alloy, for example, a CoPt alloy, a CoCr alloy, a CoCr alloy, or the like is used. Although not shown, the magnetic disk 1 may have a configuration in which an underlayer is formed between the disk substrate 2 and the magnetic layer 12. This underlayer is formed by using Cr or a Cr-based alloy or the like as the underlayer.

The magnetic layer 12 thus formed is a high portion as shown by arrows in FIG. 3A showing its cross-sectional shape and FIG. 3B showing its planar shape. The convex portion 19 and the concave portion 20, which is a low portion, are magnetized so that they are magnetized in opposite directions. That is, the method of magnetizing the protrusions 19 and the recesses 20 of the magnetic layer 12 is such that the magnetic disk 1 is rotated by a magnetizing device (not shown) and the first DC current is supplied to the magnetizing magnetic head (not shown). The magnetic head for magnetization is moved in the radial direction on the magnetic disk 1 while applying the magnetic force to the concave portion 20 and the convex portion 19 of the magnetic disk 1.
After magnetizing all the magnetic layers in the same direction, a second DC current having a polarity opposite to that of the first DC current is applied to the magnetic head for magnetizing while the magnetic head for magnetizing is rotated on the magnetic disk 1. This is performed by a method in which only the magnetic layer of the protrusion 19 of the magnetic disk 1 is magnetized in the opposite direction.

By using such a magnetizing method, since the positioning signal and the like are written on the magnetic layer 12 with one magnetizing magnetic head, the productivity of the magnetic disk 1 is improved. Further, since the magnetic disk 1 has the magnetic layer 12 on which the positioning signal and the like are written on only one surface of the disk substrate 2, the magnetization process is simplified, and the productivity can be further improved. And cost can be reduced.

Disk substrate 2 constituting magnetic disk 1
On the magnetic layer 12, a protective layer and a lubricant coating layer may be further provided on the magnetic layer 12. Materials and forming methods for forming the protective layer and the lubricant coating layer may be any of conventionally known methods, and are not particularly limited. However, as the protective layer, C is formed as a protective film by a sputtering method or the like. A typical method is to do so. Further, the lubricant application layer may be formed by applying a lubricant to the surface of the above-mentioned protective film by a dipping method or the like.

The magnetic disk 1 thus configured is
By being loaded into a recording and / or reproducing apparatus having a magnetic head floating above the recording surface 3 formed on one side thereof, recording of data information or the like on the recording surface 3 or reproduction of the recorded data information or the like is performed. Is performed.

In recent years, techniques for increasing the recording density of a magnetic disk have been actively promoted, and the recording density has reached 500 to 1000 Mbit / in ² . With such a recording density, a recording capacity of 250 to 500 Mbytes can be obtained on the magnetic disk 1 having the recording surface 3 formed on one side. Therefore, the magnetic disk 1 can ensure a practically sufficient recording capacity even if the recording surface 3 is formed only on one side. Further, it is expected that the unit price per recording capacity of the magnetic disk 1 will be further reduced by the development of the technology for increasing the recording density on the recording surface in the future.

When the magnetic disk 1 is loaded into the recording and / or reproducing apparatus, the magnetic disk 1 may be built in the recording and / or reproducing apparatus, or may be rotatably stored in a disk cartridge (not shown). Of course, the disc cartridge may be of a detachable type in which the disc cartridge is loaded into a recording and / or reproducing apparatus.

Hereinafter, a magnetic disk device 30 which is a recording and / or reproducing device incorporating the magnetic disk 1 will be described with reference to FIGS. Magnetic disk device 30
For example, as shown in FIG. 4, a disk table (not shown) rotated by a spindle motor is provided on a support substrate 31 formed using a metal plate such as an aluminum alloy. The disk table is attached to a spindle shaft of a spindle motor, and is rotated integrally with the spindle shaft at a constant angular velocity in a direction R in FIG. In the magnetic disk drive 30, the magnetic disk 1 is mounted on the disk table.

In the magnetic disk drive 30, a support shaft 32 is erected on a support substrate 31, and is attached to the support shaft 32 so that the rotation arm 33 is operated to rotate about the support shaft 32. Are arranged. The pivot arm 33 has an arm 3 whose base end is attached to the support shaft 32 and whose distal end is extended on the surface of the magnetic disk 1.
4, a leaf spring 35 connected to the distal end side of the arm portion 34 and configured to be elastically displaceable in a direction of coming into contact with and separating from the surface of the magnetic disk 1, and a magnetic head 45 attached to the distal end side of the leaf spring 35. And a floating type head slider 36. The head slider 36 is attached to the distal end of the leaf spring 35 so as to face the recording surface 3 of the magnetic disk 1.

On the other hand, a voice coil 38 constituting a voice coil motor 37 is attached from the base end side of the rotating arm 33. A pair of magnets 39 and 40 constituting the voice coil motor 37 are provided on the support substrate 31 together with the voice coil 38 so as to correspond to the voice coil 38. These magnets 39, 4
0 is a pair of yokes 41 provided on the support substrate 31,
It is arranged so as to be sandwiched between 42.

In the magnetic disk drive 30, the driving current is supplied to the voice coil 38, so that the rotating arm 3
3 is rotated about the support shaft 32 in a direction extending over the inner and outer circumferences of the magnetic disk 1. And the magnetic disk device 3
At 0, a magnetic head 45, which will be described in detail later, records or reproduces data on a recording track on the recording track forming unit 13 of the magnetic disk 1.

As shown in FIG. 5, for example, the head slider 36 has a pair of side rails 50 (50a, 50b) forming an air bearing with the magnetic disk 1 on both sides of the lower surface facing the magnetic disk 1. ) To form
A recess 51 is provided between the side rails 50. The side rails 50 are formed so as to be substantially parallel to the recording track forming section 13 formed on the magnetic disk 1 when the head slider 36 is opposed to the magnetic disk 1. The head slider 36 is mounted on each side rail 5.
A tapered portion 52 (52a, 52b) is formed on the air inflow end side opposite to the direction in which the 0 magnetic disk 1 rotates. Then, the magnetic head 45 is mounted on the head slider 36.
Is provided at an end on the air outflow side opposite to the air inflow side.

The thus configured head slider 36
Is a magnetic disk 1 that is rotated as shown in FIG.
When the magnetic disk 1 approaches the surface of the recording surface 3, the magnetic disk 1 receives a levitation force generated by an airflow flowing between the side rail 50 and the surface of the magnetic disk 1 with the rotation of the magnetic disk 1,
The magnetic disk 1 is levitated from the surface with an interval of about 50 nm.

As shown in FIG. 6, in the magnetic disk device 30, the head slider 36 floats from the surface of the magnetic disk 1 so that the magnetic head 45 attached to the head slider 36 also floats from the surface of the magnetic disk 1. The magnetic disk 1 is moved in the radial direction on the magnetic disk 1 in a non-contact manner while maintaining the flying height at a minute interval between the magnetic disk 1 and the magnetic disk 1 at about 50 nm. By moving the head slider 36 and the magnetic head 45 over the magnetic disk 1 while floating above the magnetic disk 1, wear and damage of the magnetic disk 1 and the magnetic head 45 can be prevented.

In the magnetic disk device 30, it has been confirmed that recording and reproduction can be performed normally even when the recording surface 3 of the magnetic disk 1 is not perfectly flat but is somewhat concave. Specifically, the magnetic disk drive 30
It was found that when recording and reproduction were performed using the magnetic disk 1, recording and reproduction were normally performed until the recording surface 3 side became a concave surface having a curvature radius of about 30 meters.

Therefore, the recording surface 3 of the magnetic disk 1 used in the magnetic disk device 30 only needs to have a radius of curvature of about 30 meters or more when its diameter direction is a circular arc. (2) Setting of molding conditions at the time of molding becomes easy. In addition, since the accuracy of the non-recording surface 4 of the magnetic disk 1 does not matter, the setting of the conditions for forming the disk substrate 2 is further facilitated, so that the production department can be significantly improved and the cost can be reduced.

The use of such a low-cost magnetic disk 1 can reduce the cost of the magnetic disk apparatus 30 as a whole. Further, since the magnetic disk device 30 performs recording and reproduction on the magnetic disk 1 having the magnetic film formed on one side, the magnetic head 45 on the non-recording surface 4 side and the magnetic head 45
The head slider 36, the leaf spring 35, and the arm 34 to which are attached, and screws (not shown) for attaching them
And the like can be reduced, whereby the entire apparatus can be simplified and can be manufactured at low cost.
Further, since the magnetic disk device 30 can have a space margin by reducing these components, the size and thickness of the entire device can be reduced. Furthermore, in the magnetic disk device 30, in the device assembling process, it is possible to reduce the number of assembling steps, reduce the stock of parts, shorten the lead time, and reduce the number of parts management steps.

In the above-described embodiment, the magnetic disk 1 is formed with the uneven pattern 9 on the recording surface 3 side of the disk substrate 2, but the present invention is not limited to this configuration. Of course, the recording surface 3 of the disk substrate 2 may be formed flat, and the magnetic layer 12 may be formed on the recording surface 3 to form a so-called mirror surface on the recording surface 3.

[0038]

As described in detail above, the magnetic disk according to the present invention has a magnetic film forming surface on which data information and the like are recorded / reproduced on one side of a non-magnetic substrate formed of a synthetic resin. Thereby, the process of forming the magnetic film is rationalized, and the cost can be reduced. In addition, by forming the magnetic film forming surface only on one side of the non-magnetic substrate of the magnetic disk, the conditions for molding the non-magnetic substrate are relaxed, and the cost can be reduced by improving the yield.

Further, the magnetic disk drive according to the present invention comprises:
A magnetic film forming surface is formed on one surface of the non-magnetic substrate, and the use of a low-cost magnetic disk in which the conditions for molding the non-magnetic substrate are relaxed allows the number of parts to be reduced as a whole of the magnetic disk device. Thus, the size and cost of the magnetic disk drive can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view showing a recording surface side of a magnetic disk to which the present invention is applied.

FIG. 2 is a schematic diagram showing a recording area forming portion of the magnetic disk.

FIG. 3 is a schematic diagram showing a magnetized state of a magnetic layer of the magnetic disk.

FIG. 4 is a perspective view showing an internal structure of a magnetic disk device in which the magnetic disk is built.

FIG. 5 is a perspective view showing a head slider of the magnetic disk drive.

FIG. 6 is a side view showing a state where the head slider is flying above the surface of the magnetic disk.

[Explanation of symbols]

1 magnetic disk, 2 disk substrate, 3 recording surface, 4
Non-recording surface, 5 center hole, 6 recording area forming part, 7
Clamping section, 8 landing section, 9 uneven pattern, 10 data area forming section, 11 servo mark forming section, 12 magnetic layer, 13 recording track forming section, 14
Guard band forming section, 15 address mark forming section,
16 fine mark forming section, 17 burst mark forming section, 18 header mark forming section, 19 convex section, 20
Recess, 30 magnetic disk drive, 31 support substrate, 32
Support shaft, 33 rotating arm, 34 arm, 35 leaf spring, 36 head slider, 37 voice coil motor, 38 voice coil, 39, 40 magnet, 4
1, 42 yoke, 45 magnetic disk, 50 (50
a, 50b) Side rail, 52 (52a, 52b)
Tapered part

Claims (4)

[Claims] 1. A non-magnetic substrate formed of a synthetic resin on a magnetic disk on which data information and the like are recorded and / or reproduced by a magnetic head mounted on a flying type head slider; and a non-magnetic substrate. A magnetic film forming surface formed on one side of the recording medium and on which data information and the like are recorded, wherein the magnetic film forming surface is a concave surface having a radius of curvature of about 30 meters or more. 2. A non-magnetic substrate, wherein a servo information concave / convex pattern for tracking a magnetic head of a recording and / or reproducing apparatus is integrally formed and transferred by a molding die. 2. The magnetic disk according to 1. 3. A non-magnetic substrate formed of a synthetic resin, and a magnetic film forming surface formed on one surface of the non-magnetic substrate and recording data information and the like, wherein the magnetic film forming surface has a radius of curvature. A magnetic disk having a concave surface of about 30 meters or more, and a magnetic head for recording and / or reproducing data information and the like at a height of 50 nm or less with respect to a magnetic film forming surface of the magnetic disk are mounted. A magnetic disk drive comprising: a head slider; 4. The magnetic disk according to claim 3, wherein a servo information uneven pattern for tracking the magnetic head is formed on a non-magnetic substrate.
3. The magnetic disk drive according to claim 1.