JPH10112152A - Magnetic head slider and magnetic disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable stable running, to minimize an interval between a head and a disk, to improve recording density and to enhance reliability by providing plural pieces of specified shaped projecting parts having flat parts of a prescribed total area on a surface opposite to the magnetic disk. SOLUTION: The projecting parts 3 having the flat part 6 of 100×100μm and provided with a flowing force generating taper part 7 are arranged on both the ends of the front end part of a slider 2 loading a magnetic head, and the projecting part 5 having the flat part of the same area is provided on the rear end part. The floating force by the taper part 7 is made smaller than a component acting to the projecting part 3 of pressing load to be made hardly part from a disk surface. Further, the flat surfaces of three projecting parts are made the same plane, and a gap between the read element 4 of the projecting part 5 and the disk surface is eliminated. Thus, friction force acting to the projecting parts 3 are reduced, and the moment making fall forward the slider 2 is reduced, and the slider 2 is glided smoothly, and the projecting parts 3 and the disk surface are reduced from wear and a damage, and the reliability is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk drive, and more particularly to a magnetic head slider for contact recording for recording / reproducing while sliding on a lubricating film on the surface of a magnetic disk.

[0002]

2. Description of the Related Art In a magnetic disk drive which is widely used at present, a load applied from a suspension and a floating force generated on a floating surface of a surface of a magnetic head slider facing a disk are balanced, so that a magnetic head slider and a magnetic head slider are balanced. A gap (flying gap) of at least several tens of nm is formed between the disc and the disk surface to record and reproduce signals. Conventionally,
In order to improve the recording density, studies have been made to reduce the floating gap.

However, in recent years, in order to minimize the gap between the magnetic head and the magnetic medium of the disk, there has been developed a technology relating to contact recording in which recording and reproduction are performed while the slider slides directly on the lubricating film on the disk surface without floating the slider. It is starting to be considered.

For example, in an example described in Japanese Patent Application Laid-Open No. 5-151735, three convex portions are provided on the flying surface of a normal air flying slider, and only the convex portion near the magnetic head is always in contact with the disk surface. The gap between the magnetic head and the magnetic medium of the disk is minimized.

In another example of Japanese Patent Application Laid-Open No. Hei 5-151735, a single protrusion is provided on the disk-facing surface of the magnetic head slider near the magnetic head at the rear end in the traveling direction without using the flying surface. And two projections at the front end. By applying a predetermined load to the magnetic head slider and making the three protrusions always contact the disk surface, the gap between the magnetic head and the magnetic medium of the disk is minimized without using the levitation force of air.

[0006]

In the above-described prior art air-flying slider in which a convex portion is provided on the flying surface, the recording and reproducing operation is the same as that of a normal air-flying slider except that the convex portion at the rear end contacts. Show characteristics.

That is, the front end of the magnetic head slider is lifted and tilted by the floating force generated on the magnetic head slider flying surface during recording and reproduction. The read element for recording / reproducing information is about 30 μm from the rear end of the slider.
When the slider is tilted, a slight gap is formed at the position of the read element even when the rear end of the slider is in contact with the disk surface. Therefore, the recording density cannot be increased.

Further, in the example in which the air bearing surface is not provided, the above-described inclination does not occur, so that no gap is generated between the read element portion and the disk. However, a frictional force generated in the convex portion generates a moment in the direction of lifting the rear end of the slider,
If the frictional force is large, the slider becomes cramped and the rear end rises from the disk surface, and the recording gap becomes large, and at the same time, the behavior of the slider becomes unstable and normal recording / reproduction becomes impossible. In particular, in recent years, the surface of the disk has tended to be smoothed in order to reduce the distance between the disk surface and the magnetic medium of the disk, and the above-mentioned slippage has been likely to occur because the friction coefficient increases. Further, since the two convex portions are always in contact with the disk surface, both the disk surface and the convex portions are likely to be worn or damaged by the generated frictional force. Since the moment due to the frictional force acts in a direction in which the front end convex portion is pressed against the disk surface, the wear and damage are particularly likely to occur at the front end convex portion.

SUMMARY OF THE INVENTION It is an object of the present invention to increase the recording density by minimizing the distance between the read element portion and the disk, and to stably record and reproduce data without using a slider even when a smooth disk is used. An object of the present invention is to provide a magnetic head slider that is less likely to be worn or damaged by frictional force, and to realize a large-capacity and highly reliable magnetic disk drive.

[0010]

SUMMARY OF THE INVENTION The object of the present invention is as follows.
One at the rear end of the surface facing the magnetic disk in the traveling direction,
The front end has a plurality of convex portions having flat portions, all the flat portions are on the same plane, and the total area is 0.
This is achieved by providing a levitation force generating portion that generates a levitation force of 0.4 mm ² or less and generates a levitation force smaller than the component force acting on the front end convex portion of the pressing load on the front end portion convex portion.

According to the present invention, a levitation force is generated at the front end projection, but the load on the disk surface of the front end projection which is equivalent to the component force acting on the front end projection of the pressing load is smaller than that of the front end projection. Since the convex portion does not separate from the disk surface, the slider does not tilt with respect to the disk surface,
Furthermore, since the flat parts of all the convex parts are on the same plane,
There is no gap between the read element and the disk surface.

However, when a smooth disk having a surface roughness Ra of about 1 nm is used, at the time of stopping the disk, a lubricating force of about 100 gf per 1 mm ² is generated on the flat portion of the projection. For example, in a magnetic disk device having a disk with a diameter of 2.5 mm and a device having two disks mounted thereon, the starting torque for the disk is about 27 gf · mm, and the attraction force per slider is about 4 gf. Therefore, the total area of the flat portions of the convex portions is 0.1.
It needs to be 04 mm ² or less.

Further, since a floating force is generated at the front end projection, the load of the front end projection on the disk surface is reduced, and the equivalent force of the drag from the disk surface is also reduced.
As a result, the frictional force acting on the front end convex portion is reduced, and the moment for causing the slider to be flattered is reduced, so that the slider can stably slide on the disk surface even with a smooth disk. At the same time, the frictional force acting on the front end protrusion is reduced, so that the front end protrusion and the disk surface are less likely to be worn or damaged.

That is, according to the present invention, it is possible to increase the recording density by minimizing the distance between the magnetic head and the disk, and to stably record and reproduce data without using a slider even when a smooth disk is used. A magnetic head slider that is less likely to be worn or damaged by frictional force; and a large-capacity and highly reliable magnetic disk drive can be realized.

[0015]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a perspective view of a first embodiment to which the present invention is applied. In the example of FIG. 1, a slider 2 on which the magnetic head 1 is mounted is provided with a front end projection 3 at both ends of a front end and a rear end projection 5 including a read element section 4 of the magnetic head 1.
Further, the front end convex portion 3 and the rear end convex portion 5 have 100 × 100
A μm flat portion 6 and a tapered portion 7 for generating an appropriate floating force are provided on the inflow end side of the front end projection 3. As a result, the tapered portion 7 generates a floating force on the front end convex portion 3, but is smaller than the component force of the pressing load acting on the front end convex portion 3, and the front end convex portion 3 does not separate from the disk surface. Therefore, the slider 2 is not inclined with respect to the disk surface, and since the three flat portions 6 are provided on the same plane, no gap is generated between the read element portion 4 and the disk surface. At the same time, since a floating force is generated in the tapered portion 7, the drag of the front end convex portion 3 from the disk surface also decreases.
As a result, the frictional force acting on the front end projection 3 decreases,
Since the moment for pinching the slider 2 is reduced, the slider 2 can stably slide on the disk surface even if a smooth disk is used. At the same time, the frictional force acting on the front end protrusion 3 is reduced, so that the front end protrusion 3 and the disk surface are less likely to be worn or damaged.

As described above, when a smooth disk having a surface roughness Ra of about 1 nm is used, when the disk is stopped, a lubricating force of about 100 gf / mm ² is generated on the flat portion of the convex portion by the lubricant. . For example, 2.5mm
In a magnetic disk device having a disk having a diameter of two disks, the starting torque for the disk is about 27 gf · mm, and the attraction force allowed for one slider is about 4 gf. The total area of the flat portions needs to be 0.04 mm ² or less.

This will be described in detail with reference to FIG. In FIG. 2, the load from the suspension and the drag from the disk surface acting on the front end convex portion 3 and the rear end convex portion 5 are represented by W and F, respectively.
1, F2, the lifting force acting on the tapered portion 7 is Fa, the friction coefficient between the two convex portions and the disk surface is μ, the distance from the disk surface to the slider rotation center is h, and the front and rear projections and the rear end from the slider rotation center. Assuming that the arm length of the moment from the convex portion to the load point is L1, L2, and L3, F1 + F2 + Fa = W (1) L2F2 + μH (F1 + F2) = L3W + L1 (F1 + Fa) (2) Here, the ratio of F1 to Fa is F1: Fa = 1: N (3), and F2> 0 because the rear end convex portion 5 does not lift from the disk surface. Then, equation (1) becomes as follows.

Μ <(1 + N) · (L1 + L3) / H (4) Here, in the example in which the air bearing surface is not provided in JP-A-5-151735, the levitation force is applied to the front end protrusion 3. Since it has not been generated, N = 0. In this case, the maximum friction coefficient that can not be smoothed from the equation (4) is (L1 + L3) / H.
However, when a levitation force is generated at the front end convex portion according to the present invention and, for example, a levitation force equivalent to F1 is applied to the drag from the disk surface, N = 1, and the maximum unobtrusiveness is obtained. The coefficient of friction is 2 (L1 + L3) / H, and can withstand twice the coefficient of friction.

FIG. 3 is a perspective view of a second embodiment to which the present invention is applied. In the example of FIG. 1, the tapered portion 7 is provided on the front end convex portion 3 to generate a floating force. However, in FIG. 3, a step portion 8 is provided on the inflow end side of the front end convex portion 3 to generate the floating force.
Is provided. In a magnetic disk device, the peripheral speed changes depending on the radial position of the disk. In a commonly used rotary access type magnetic disk device, the magnetic head slider angle with respect to the tangential direction of the disk also changes depending on the radial position. Therefore, the flying force generated by the radial position changes, and in a normal flying magnetic head slider, the flying gap and the flying attitude change. In the case of the first embodiment, since the floating force generated in the tapered portion 7 changes depending on the radial position, the above-described effect of reducing the frictional force differs depending on the radial position. Since the maximum levitation force is limited to prevent the front end convex portion from floating, the effect of reducing the frictional force cannot be expected much at the radial position where the minimum levitation force is generated. However, in the example of FIG. 3, a stepped portion 8 corresponding to a so-called step bearing is provided instead of the tapered portion 7 in order to generate a floating force. Therefore, compared with the case where the tapered portion 7 is provided, the change in the floating force depending on the radial position is relatively small, so that a relatively uniform effect of reducing the frictional force regardless of the radial position can be expected, and the stability of the slider behavior is stable. And wear and damage can be reduced.

FIG. 4 is a side view of a third embodiment to which the present invention is applied. In the example of FIG. 4, the slider 2 of the first embodiment, to which an appropriate pressing load is applied by the suspension 9, is moved to the smooth disk 1 having a surface roughness Ra of 1 nm or less.
I'm glide over 0. The slider 2 of the first embodiment, in which no gap is formed between the read element portion 4 and the disk surface, has Ra of 1
By sliding on the smooth disk 10 of nm or less, the distance between the read element unit 4 and the magnetic medium (not shown) of the smooth disk 10 can be reduced, so that the storage capacity of the entire magnetic disk device can be increased. At the same time, since the total area of the flat portions 6 is small, the attraction force is small, and furthermore, it is unlikely that the frictional force causes the flattening, so that the reliability of the magnetic disk device can be improved.

[0022]

As described above, the recording density is increased by minimizing the distance between the magnetic head and the disk, and even when a smooth disk is used, the recording and reproduction can be performed stably without the slider being jammed. A magnetic head slider that is less likely to be damaged can be provided, and a large-capacity and highly reliable magnetic disk drive can be realized.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a first embodiment of the present invention.

FIG. 2 is a conceptual diagram of a force acting on the magnetic head slider of the first embodiment according to the present invention.

FIG. 3 is a perspective view showing a second embodiment of the present invention.

FIG. 4 is a side view showing a third embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Magnetic head, 2 ... Slider, 3 ... Front end convex part, 4 ...
Read element portion, 5: rear end convex portion, 6: flat portion, 7: tapered portion, 8: step portion, 9: suspension, 10: smooth disk.

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Toshihiro Arisaka 502 Kandamachi, Tsuchiura-shi, Ibaraki Pref.

Claims (6)

[Claims] 1. A magnetic head slider having a magnetic head for recording and reproducing information while relatively moving a surface of a rotating magnetic disk, wherein the magnetic head slider is a rear end portion of a surface facing the magnetic disk in a traveling direction. Each having a plurality of flat portions at the front end thereof, all of the flat portions being on the same plane, and having a total area of 0.04 m.
A magnetic head slider characterized in that a levitation force generating portion that generates a levitation force that is less than or equal to m ² and is smaller than a component force acting on the front end convex portion of the pressing load is provided at the front end convex portion. 2. A magnetic head slider having a magnetic head for recording and reproducing information while relatively moving a surface of a rotating magnetic disk, wherein the magnetic head slider is provided at a rear end of a surface facing the magnetic disk in a traveling direction. One, having a plurality of flat portions at the front end, and all the flat portions are on the same plane, and the total area is 0.04 m.
m ² or less, and a tapered portion for generating a floating force smaller than a component force acting on the front end convex portion of the pressing load is provided on the front end convex portion. 3. A magnetic head slider having a magnetic head for recording and reproducing information while relatively moving a surface of a rotating magnetic disk, wherein the magnetic head slider is provided at a rear end of a surface facing the magnetic disk in a traveling direction. One, having a plurality of flat portions at the front end, and all the flat portions are on the same plane, and the total area is 0.04 m.
m ² or less, to the front end protrusion, pressing the magnetic head slider, characterized in that a step portion that generates a smaller floating force than the component force acting on the front end protrusion of the load. 4. A magnetic disk drive comprising: a rotating magnetic disk; and a magnetic head slider provided with a magnetic head for recording and reproducing information while relatively moving the surface of the magnetic disk. One surface is provided at the rear end of the surface facing the disk in the advancing direction, and one protrusion is provided with a plurality of flats at the front end. The flats of all the protrusions are on the same plane and the total area is 0. .04 mm ² or less, a levitation force generating portion that generates a levitation force smaller than the component force acting on the front end convex portion of the pressing load is provided at the front end convex portion, and the surface roughness of the magnetic disk A magnetic disk drive characterized in that Ra is used for a disk having a Ra of 1 nm or less. 5. A magnetic disk drive comprising: a rotating magnetic disk; and a magnetic head slider having a magnetic head for recording and reproducing information by relatively moving the surface of the magnetic disk, wherein the magnetic head slider is a magnetic disk. Has a convex portion having one flat portion at the rear end portion and a plurality of flat portions at the front end portion in the traveling direction of the surface opposing the flat surface, and the flat portions of all the convex portions are on the same plane, and the total area is 0. 0.4 mm ² or less, and a tapered portion that generates a floating force smaller than the component force acting on the front end convex portion of the pressing load is provided on the front end convex portion, and the magnetic disk has a surface roughness Ra of 1 nm. A magnetic disk drive used for: 6. A magnetic disk drive comprising: a rotating magnetic disk; and a magnetic head slider having a magnetic head for recording and reproducing information by relatively moving the surface of the magnetic disk, wherein the magnetic head slider is a magnetic disk. A convex portion having one flat portion at the rear end and a plurality of flat portions at the front end in the traveling direction of the surface opposite to the flat surface, wherein the flat portions of all the convex portions are provided on the same plane; Part total area is 0.04mm ²
The following is a configuration in which the front end convex portion is provided with a step portion that generates a levitation force smaller than the component force acting on the front end convex portion of the pressing load, and the magnetic disk has a surface roughness Ra of 1
A magnetic disk drive characterized in that the magnetic disk drive is used for those having a diameter of less than 10 nm.