WO1998027548A1

WO1998027548A1 - Magnetic disk and magnetic disk apparatus using the same

Info

Publication number: WO1998027548A1
Application number: PCT/JP1996/003690
Authority: WO
Inventors: Shinji Yonemura; Hiromitsu Tokisue; Hideaki Tanaka; Yoshinori Takeuchi
Original assignee: Hitachi, Ltd.
Priority date: 1996-12-18
Filing date: 1996-12-18
Publication date: 1998-06-25

Abstract

In a CSS region of a magnetic disk, a means for setting the flying height of a magnetic slider in the CSS region higher than that in a data region is provided. The surface of the CSS region of the magnetic disk is rough. This prevents the attraction of the magnetic disk and the magnetic head slider to each other when the magnetic disk apparatus is stopped, and ensures the slide resistance of the CSS region. A magnetic disk apparatus mounted with such a magnetic disk has an excellent reliability and achieves a high recording density even when the flying height of the magnetic head slider is small.

Description

Description Magnetic disk and magnetic disk device using the same

The present invention relates to a magnetic disk and a magnetic disk device, and more particularly, to a magnetic disk which is excellent in reliability even under a condition where the flying height of a magnetic head slider is low and which can realize a high recording density, and a magnetic disk device using the same. Background art

In a magnetic disk device, the smaller the gap between a rotating magnetic disk and a magnetic head that records and reproduces information on the magnetic disk, the greater the amount of information that can be recorded and reproduced on a magnetic disk as a recording medium. For this reason, the gap between the magnetic disk and the magnetic head slider on which the magnetic head is mounted has been steadily becoming narrower. At present, magnetic disk drives with a flying height of the magnetic head slider of less than 10 O nm and less than 5 O nm are on the market. In addition, as for magnetic disks, the mainstream is a sputter disk on which a magnetic layer is formed by a sputtering method, and the smoothness of the magnetic disk surface is improved.

As described above, when the smoothness of the magnetic disk is improved, there arises a problem that the magnetic head slider and the magnetic disk stick to each other when the magnetic disk device is stopped. If the suction force exceeds the starting torque of the spindle, the magnetic disk drive cannot be started, or the suspension or the magnetic disk supporting the magnetic head slider is damaged.

In the past, mechanical adsorption, plasma processing, laser processing, etc., were used to provide irregularities of several 10 nm on the entire disk surface to prevent adsorption. As a means for further reducing the flying height of the magnetic head slider, as shown in JP-A-4-178991, the surface roughness of the magnetic disk in the CSS (Contact Start Stop) area is made larger than the surface roughness of the data area. A method has been proposed to prevent the magnetic head slider and the magnetic disk from being attracted to each other when the magnetic disk drive is started and stopped. The magnetic disk is divided into a CSS area and a data area. Data recording is performed in the data area, and starting and stopping of the magnetic disk device is performed in the CSS area. Therefore, the surface roughness of the data area can be made smaller than that of the CSS area, and the flying height of the magnetic head slider can be further reduced. However, in order to prevent the magnetic head slider and the magnetic disk from sticking when the magnetic disk device is stopped, even this method requires the surface roughness of the CSS area to be several tens of _nanometers .

As described above, in the above-described conventional technology, the unevenness is provided in the CSS region on the surface of the magnetic disk in order to prevent the magnetic head slider from being attracted to the magnetic disk, but the unevenness has almost no effect on the flying height of the magnetic head slider. The flying heights in the CSS area and the data area are almost the same. Therefore, when the flying height of the magnetic head slider further decreases, it is expected that the flying height of the magnetic head slider will be lower than the protrusion height of the CSS region. In this case, the magnetic head slider and the magnetic disk are always in contact with each other in the Css region, and there is a problem in terms of sliding resistance. If the height of the protrusions in the CSS area is reduced to avoid this situation, the surface roughness of the CSS area will be extremely small, and it will not be possible to prevent the magnetic head slider from sticking to the magnetic disk when the magnetic disk drive starts and stops The problem arises.

The present invention ensures sliding resistance in the CSS area even when the flying height of the magnetic head slider in the data area of the magnetic disk is extremely low such that it becomes smaller than the protrusion height in the CSS area. Starting the magnetic disk unit, It is an object of the present invention to provide a magnetic disk capable of preventing attraction to a magnetic head slider when stopped.

Another object of the present invention is to provide a magnetic disk device equipped with the above magnetic disk. Disclosure of the invention

The present invention provides a means for increasing the flying height of the magnetic head slider in the CSS area in the CSS area of the magnetic disk to be higher than the flying height in the data area, so that the surface of the magnetic disk in the CSS area is roughened. This prevents the magnetic disk and the magnetic head slider from sticking to each other when the device is stopped, and ensures sliding resistance in the CSS area.

In addition, a magnetic disk drive equipped with such a magnetic disk has excellent reliability and exhibits high recording density even under the condition that the flying height of the magnetic head slider is low. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic configuration diagram of a magnetic disk drive on which a magnetic disk having a CSS area and a data area is mounted.

Fig. 2 is a schematic diagram showing the relationship between the surface roughness of the CSS area and the flying height when the magnetic head slider is flying low, and is a view from above of the magnetic disk.

FIG. 3 is a schematic diagram showing the relationship between the surface roughness of the CSS region and the flying height during low flying, and is a partial sectional view of a magnetic disk.

FIG. 4 is a diagram for explaining the concept of the present invention.

FIG. 5 is a partial top view of a magnetic disk showing the first embodiment of the present invention. FIG. 6 is a partial sectional view of the CSS area of the magnetic disk according to the first embodiment. FIG. 7 is a view of the positive pressure slider viewed from the rail surface side.

FIG. 8 is a longitudinal sectional view of the positive pressure slider.

FIG. 9 is a partial top view of a magnetic disk showing an application example of the first embodiment. FIG. 10 is a partial cross-sectional view of a magnetic disk showing a second embodiment of the present invention.

FIG. 11 is a partial sectional view of a magnetic disk showing a third embodiment of the present invention.

FIG. 12 is a top view of FIG.

FIG. 13 is a view of the negative pressure slider viewed from the rail surface.

FIG. 14 is a longitudinal sectional view of the negative pressure slider. BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 schematically shows the magnetic disk drive of the present invention. The magnetic disk 2 is divided into a CSS area 3 and a data area 4. The magnetic head slider 1 is supported by the load arm 11 via a suspension, and is positioned at an arbitrary position on the magnetic disk 2 by the positioning mechanism 12. When the magnetic disk drive is started and stopped, the magnetic head slider is on the CSS area 3, so that the surface of the data area 4 does not need to consider the attraction of the magnetic head slider 1 and can be formed smoothly. The CSS area 3 has a texture 5 (see Fig. 2) that has protrusions or roughness by mechanical processing, plasma processing, laser processing, etc. to prevent the magnetic head slider 1 and the magnetic disk 2 from attracting. ) Is formed.

By the way, in the above-mentioned prior art, the texture 5 provided to prevent the magnetic head slider 1 and the magnetic disk 2 from attracting each other does not have the effect of increasing the flying height of the magnetic head slider 1. Referring to FIGS. 2 and 3, assuming that the flying height in data area 4 is h and the flying height in CSS area 3 is h ', So = 11 '. Therefore, when the flying height h is further reduced, the protrusion height H of the CSS region 3 can be H> h '(= h) as described above. In this case, the magnetic head slider 1 and the magnetic disk 2 are always in contact in the CSS area 3, and there is a problem in sliding resistance. On the other hand, when H <h ′ (= h), the surface roughness of the CSS area 3 becomes small, and it is difficult to avoid the magnetic head slider 1 and the magnetic disk 2 from being attracted when the magnetic disk device is stopped. FIG. 4 shows a conceptual diagram of the present invention. As shown in FIG. 4, if h ′> h, the surface roughness of the CSS area 3 can be kept sufficiently high to avoid the magnetic head slider 1 and the magnetic disk 2 from being attracted, and , H ′> H, the sliding resistance in the CSS region 3 is also ensured.

In order to make the flying height in the CSS area 3 higher than the flying height in the data area 4, the force to increase the pressure generated between the magnetic head slider 1 and the magnetic disk 2 in the CSS area 3 or the magnetic head slider 1 In this case, it is conceivable to reduce the negative pressure in CSS area 3.

FIGS. 5 and 6 show a first embodiment of the present invention. The data area 4 of the magnetic disk 1 is formed to be smooth, and the surface shape of the CSS area 3 is provided with a groove 8 having a depth of several μπι so as to oppose in the lateral direction. When the magnetic disk 2 rotates, the air between the magnetic head slider 1 and the magnetic disk 2 is pushed into the groove 8 and is blocked at the end thereof to obtain a pressure rise. The pressure generated can be adjusted by selecting the width, length and depth of the groove 8. It is desirable that the shape be selected so that sufficient pressure is generated to increase the flying height in CSS area 3. For example, when the length of the magnetic head slider 1 is 2.05 mm and the width is 1.6 mm, the groove 8 has a radial length of 2 mm, a circumferential width of 0.05 mm, The depth is 0.5 μπι. By forming grooves 8 in the CSS area 3 of the magnetic disk 2 to form a group bearing in this manner, the conventional mechanically formed technology in the circumferential direction is used. Since the pressure generated between the magnetic head slider 1 and the magnetic disk 2 is higher than in the case of a texture or dot type texture, the flying height of the magnetic head slider 1 can be increased. Therefore, the surface roughness due to the texture 5 can be increased, and the attraction between the magnetic head slider 1 and the magnetic disk 2 when the magnetic disk device is stopped can be effectively prevented. The magnetic head slider 1 may be a positive pressure slider or a negative pressure slider. Fig. 7 shows a view of the positive pressure slider viewed from the rail surface side, and Fig. 8 shows a cross-sectional view cut in the longitudinal direction. In the positive pressure slider, a taper 12 is formed at the tip, two rails 15 are formed from the end of the taper 12 to the rear end, and a groove 16 is formed between the two rails. It is formed.

The shape of the groove 8 for increasing the pressure generated between the magnetic head slider 1 and the magnetic disk 2 may be wedge-shaped as shown in FIG. The pressure generated between the magnetic head slider 1 and the magnetic disk 2 can be higher in the shape shown in FIG.

FIG. 10 is a partial sectional view of a magnetic disk according to a second embodiment of the present invention. No.

The groove 8 for increasing the pressure generated between the magnetic head slider 1 and the magnetic disk 2 in FIG. 6 showing the embodiment of FIG. 1 is formed with a convex portion 9 having a height of several tens nm or less as shown in FIG. Even if it does, the same effect can be expected. In this case, the air between the magnetic head slider 1 and the magnetic disk 2 is blocked by the projections 9 and a high pressure is obtained. Similarly to the groove 8 of the first embodiment, the pressure generated in the convex portion 9 can be adjusted by selecting the width, length, and height. It is desirable that the shape be selected so that sufficient pressure is generated to increase the flying height in CSS area 3. The protrusion 9 may be lower than the texture 5. Since the flying height in the CSS region 3 can be increased by the convex portion 9, the surface roughness due to the texture 5 can be increased, and the magnetic head slider 1 and the magnetic disk 2 can be prevented from being attracted. Magnetic The head slider 1 may be a positive pressure slider or a negative pressure slider. Further, the convex portion 9 may be wedge-shaped as shown in FIG. 9 as in the first embodiment.

FIG. 11 is a partial cross-sectional view of a third embodiment of the present invention, and FIG. 12 is a view of the disk 2 as viewed from above. In this case, the magnetic head slider 1 is a negative pressure slider. FIG. 13 shows an example of the negative pressure slider viewed from the rail surface side, and FIG. 14 shows a longitudinal sectional view thereof. The air force compressed by the taper 12 and the cross rail 13 expands in the negative pressure groove 6 to a pressure lower than the atmospheric pressure, thereby generating a negative pressure. If the negative pressure is reduced, the flying height of the magnetic head slider 1 increases. Therefore, as shown in FIGS. 11 and 12, the data area 4 is formed smoothly, and the surface of the magnetic disk 2 facing the cross rail 13 of the magnetic head slider 1 when starting and stopping the magnetic disk device. A number of circumferential grooves 7 are provided in the CSS area 3. By selecting the width and depth of the groove 7, the reduction of the negative pressure can also be adjusted. It is desirable to select the width and depth of the groove 7 so that a sufficient negative pressure can be reduced in order to increase the flying height in the CSS region 3. For example, when the magnetic head slider 1 having the same size as that of the first embodiment is used, the groove 7 has a width of 200 Hm and a depth of 1 μm.

Negative pressure is generated by the air compressed by the taper 12 and the cross rail 13 of the magnetic head slider 1 expanding in the negative pressure groove 6. If a groove 7 having a depth of several meters / m is provided in the CSS area 3 on the surface of the magnetic disk 2 facing the cross rail 13 of the magnetic head slider 1, air compression due to the cross rail 13 will decrease. The pressure decreases. When the magnetic head slider 1 flies in the CSS area 3, the negative pressure is reduced by the groove 7 to increase the flying height. With this method, the flying height during CSS can be increased, so the surface roughness of CSS area 3 can be increased by texture 5 and the magnetic head slider 1 and the magnetic The suction of the disk 2 can be prevented. Also, in FIGS. 11 and 12, the magnetic head slider 1 reaches a high flying height quickly when the magnetic disk device is started due to the decrease in the negative pressure. The contact time is shorter and the CSS properties are improved. Industrial applicability

According to the present invention, the surface of the CSS area of the magnetic disk can be roughened, so that the magnetic disk and the magnetic head slider are not attracted to each other when the magnetic disk device is stopped, and the sliding resistance in the CSS area is ensured. Can be. In addition, a magnetic disk device equipped with such a magnetic disk has excellent reliability and exhibits high recording density even under the condition that the flying height of the magnetic head is low.

Claims

In a magnetic disk in which the surface roughness of the CSS area is larger than the surface roughness of the data area, the flying height of the magnetic head slider in the CSS area in the cSS area is larger than the flying height in the data area. A magnetic disk characterized by having means for increasing the height.

Means for making the flying height of the magnetic head slider in the CSS area higher than the flying height in the data area is to apply a specific shape to the surface of the CSS area to thereby generate a pressure generated between the magnetic head slider and the magnetic head slider. 2. The magnetic disk according to claim 1, wherein a force acting in a direction in which the magnetic head slider is lifted is increased.

2. The method according to claim 1, wherein the means for making the flying height of the magnetic head slider in the CSS area higher than the flying height in the data area is a group bearing provided in the CSS area. Magnetic disk.

4. The magnetic disk according to claim 3, wherein the group bearing is a plurality of horizontally long grooves provided at predetermined intervals in a circumferential direction.

5. The magnetic disk according to claim 4, wherein the groove has a wedge shape.

6. The means for making the flying height of the magnetic head slider in the CSS area higher than the flying height in the data area is a plurality of horizontally long protrusions provided at predetermined intervals in the circumferential direction in the CSS area. The magnetic disk according to claim 1, wherein:

7. The magnetic disk according to claim 6, wherein the projection has a wedge shape.

8. When the magnetic head slider is of a negative pressure type, the means for making the flying height of the negative pressure type magnetic head slider in the CSS area higher than the flying height in the data area is: This is a circumferential groove provided in a portion opposed to the negative pressure generating portion, and when the negative pressure type magnetic head slider floats in the CSS area, the groove reduces the negative pressure to increase the flying height. 2. The magnetic disk according to claim 1, wherein:

9. A magnetic disk in which the surface roughness of the CSS area is larger than the surface roughness of the data area, A magnetic disk storage device comprising: a magnetic head slider that floats on the magnetic disk and performs Z-read of data, and a positioning mechanism that positions the magnetic head slider at a desired position on the magnetic disk.

The magnetic disk device according to claim 1, wherein the magnetic disk includes means for increasing a flying height of the magnetic head slider in the CSS region in the CSS region to a flying height in the data region.

0. The means for making the flying height of the magnetic head slider in the CSS area of the magnetic disk higher than the flying height in the data area comprises: giving a specific shape to the surface of the CSS area; 10. The magnetic disk device according to claim 9, wherein the pressure generated between the magnetic disk slider and the magnetic head slider is increased to increase a force acting in a direction in which the magnetic head slider floats.

11. The means for making the flying height of the magnetic head slider higher in the CSS area of the magnetic disk than in the data area is a group bearing provided in the CSS area. 10. The magnetic disk drive according to claim 9, wherein:

12. The magnetic disk drive according to claim 11, wherein the group bearing is a plurality of horizontally elongated grooves provided at predetermined intervals in a circumferential direction of the magnetic disk.

13. The magnetic disk drive according to claim 12, wherein the groove has a wedge shape.

14. The means for making the flying height of the magnetic head slider in the CSS area of the magnetic disk higher than the flying height in the data area may include a plurality of horizontally long, horizontally extending parts provided in the CSS area at predetermined intervals in the circumferential direction. 10. The magnetic disk drive according to claim 9, wherein the magnetic disk drive is a projection.

15. The magnetic disk drive according to claim 14, wherein the projection has a wedge shape.

16. In the case where the magnetic head slider is a negative pressure type, means for making the flying height of the negative pressure type magnetic head slider in the CSS region higher than the flying height in the data region is as follows: A circumferential groove provided in a portion of the magnetic head slider facing the negative pressure generating portion, and when the negative pressure type magnetic head slider floats in the CSS area, the negative pressure is reduced by the groove. 10. The magnetic disk drive according to claim 9, wherein the flying height is increased by increasing the height.