JPH10283745A - Negative pressure slider and magnetic disk drive - Google Patents

Abstract

(57) Abstract: An object of the present invention is to reduce the accumulation of lubricant in grooves on the air bearing surface of a slider, reduce the increase in adhesive force between a slider and a disk recording medium, and reduce processing variations. It is an object of the present invention to provide a negative pressure slider having a small variation in the flying height even if the length of an air introduction portion for generating a negative pressure changes, and a magnetic disk device using the same. A negative pressure slider (100) includes an air inlet (13).
0, 132, cross rails 120, 122, side rails 110, 112, a first groove 140, and a magnetic transducer 180. Further, the negative pressure slider 100 connects the first groove 140 and the second groove 160 to the second groove 160 provided on the air inflow end side of the slider so as to separate the air introduction portions 130 and 132. In addition, a slit 150 provided to separate the cross rails 120 and 122 is provided. In addition, the air introduction sections 130 and 132 are cross rails 120 and 122.
The width W2 of the portion connected to the side rails 110, 11
2 is a width W of a portion connected to the cross rails 120 and 122.
It is narrower than 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

The present invention relates to a negative pressure slider and a magnetic disk device using the same, and more particularly, to a negative pressure slider suitable for use in a high recording density type magnetic disk device and a magnetic disk device using the same.

[0002]

2. Description of the Related Art In order to increase the recording density of a magnetic disk drive, it is necessary to reduce a flying height, which is a gap between a slider having a magnetic head and a disk. 2. Description of the Related Art A conventional magnetic disk device uses a negative pressure slider that floats on a rotating disk recording medium while maintaining a small interval. Since the negative pressure slider increases the negative pressure with the increase of the peripheral speed caused by the change of the flying radius position from the inner circumference to the outer circumference on the disk recording medium, the negative pressure slider suppresses the increase of the flying height with the increase of the peripheral speed. be able to. Therefore, the negative pressure slider can keep the flying height constant with respect to the change in the peripheral speed caused by the difference in the flying radius position on the disk recording medium.

As a negative pressure slider, for example, as described in US Pat. No. 5,490,025, dust particles existing on a disk are captured by a wall on the air inflow end side of a cross rail. In addition, there is known a device which does not enter a narrow gap between a slider rail and a disk.

Further, as described in US Pat. No. 5,062,017, a portion where the rail width is reduced is formed at about 1/3 from the air inflow end side of the side rail. Thus, it is known that the change in the flying height due to the skew angle can be reduced. Further, since the cross rail is recessed from the rail surface toward the groove, the contact area between the slider and the disk can be reduced when the apparatus is started.

In general, the negative pressure groove of the negative pressure slider may potentially collect dust in the apparatus. Therefore, in order to put the negative pressure slider to practical use, it is essential to clean the environment in the apparatus. Was. Today, with the progress of clean technology, even if a negative pressure slider is used, dust and the like hardly accumulate in the negative pressure groove portion, and the negative pressure slider can be used with high reliability.

In order to remove the influence of dust in the apparatus, for example, as described in Japanese Patent Application Laid-Open No. Hei 6-44719, a V-shape is formed toward the air inflow end so as to separate the cross rail from the tapered portion. One that forms an opening groove that is open to the outside is known.

[0007]

However, if the disk device is operated for a long time, the lubricant applied to the disk and the grease of the bearing used in the device leak out and adhere to the negative pressure groove. This has been clarified by the study of the present inventors. If the slider stops contacting the disk when the device is stopped, the grease adhering to the negative pressure groove leaks into the gap between the slider and the disk, forming a meniscus, and it is clear that a large adhesive force is generated. Was. When the magnetic disk device is restarted after the meniscus is formed, a large adhesive force is generated between the slider and the disk, and the device cannot be restarted, or the adhesive force exceeds the yield stress of the suspension and the suspension is destroyed, Otherwise, a defect such as a scratch on the disk occurs.

As a result of investigation and research into the cause, it has been found that the portion of the groove on the air bearing surface of the slider where the lubricant is accumulated corresponds to the portion where the flow of air is stagnant in the groove. Conventionally, a magnetic disk drive employs a contact start / stop (CSS) system in which a negative pressure slider slides on a disk recording medium at the time of start and stop.
In order to ensure slidability during CSS, a thin and uniform lubricant is applied on the disk recording medium. Although the viscosity of the lubricant is initially high, the viscosity decreases with the rotation of the disk recording medium, so that the lubricant becomes a mist and floats on the disk recording medium.

The flying height of the slider is 200 n as in the prior art.
When m is large, there is no influence of the mist of the lubricant, but it is affected by the mist by lowering the flying height in order to increase the recording density. The negative pressure slider has a groove surrounded by a rail that generates a negative pressure when floating on the air bearing surface. Depending on the shape of the rail, a portion where the flow of air is stagnant in the groove, in other words, the speed of the air flow is reduced. Some parts are zero. It has been found that mist-like lubricant accumulates in the portion where the flow of air is stagnant in this groove, that is, in the groove on the air bearing surface of the slider.

[0010] For the adhesion of the mist-like lubricant, for example, even the configuration described in Japanese Patent Application Laid-Open No. 6-44719 has an effect similar to the prevention of the adhesion of dust. it is conceivable that. However, in the device described in Japanese Patent Application Laid-Open No. 6-44719, the area of the tapered portion is large because the width of the tapered portion serving as an air introduction portion for generating a negative pressure is large. Therefore, if the length of the tapered portion changes due to variations during processing, the negative pressure generated in the tapered portion also changes, resulting in a problem that the flying height of the negative pressure slider changes greatly.

An object of the present invention is to reduce the accumulation of lubricant in grooves on the air bearing surface of a slider, reduce the increase in adhesive force between a slider and a disk recording medium, and generate a negative pressure due to processing variations. It is an object of the present invention to provide a negative pressure slider having a small variation in the flying height even if the length of the air introducing portion changes, and a magnetic disk device using the same.

[0012]

[Means for Solving the Problems]

(1) In order to achieve the above object, the present invention provides an air introduction part formed on an air bearing surface of a slider and located on an air inflow end side, a cross rail formed following the air introduction part, A pair of side rails extending in the longitudinal direction of the slider formed following the cross rail; a first groove formed in a region surrounded by the cross rail and the side rail; A negative pressure slider having a magnetic transducer provided on the outflow end side, a second groove portion provided on the air inflow end side of the slider so as to separate the air introduction portion, the first groove portion and the second groove portion; A slit provided to connect the second groove portion and to separate the cross rail,
A width of a portion where the air introduction portion is connected to the cross rail is smaller than a width of a portion where the side rail is connected to the cross rail. With such a configuration,
By providing the second groove and the slit, the maximum pressure can be reduced, the accumulation of lubricant in the groove on the air bearing surface of the slider can be reduced, and the increase in the adhesive force between the slider and the disk recording medium can be reduced. It will be. In addition, by making the width of the portion where the air introduction portion is connected to the cross rail narrower than the width of the portion where the side rail is connected to the cross rail, air introduction for generating a negative pressure due to processing variation. Even if the length of the portion changes, variation in the flying height can be reduced.

(2) In the above (1), preferably,
The depth of the second groove is greater than or equal to the depth of the first groove. With such a configuration, the air is not pressurized on the air inflow side of the cross rail, so that the maximum pressure can be reduced, the stagnation of the speed can be reduced, and the accumulation of the grease can be prevented.

(3) In the above (1), preferably,
The maximum width of the cross rail is 150 μm or less. With such a configuration, the maximum pressure at the outer peripheral position of the magnetic disk can be made equal to or lower than a predetermined pressure, so that a stagnation portion of the air flow is hardly formed, and the accumulation of grease or the like can be prevented.

(4) In order to achieve the above object, the present invention provides a rotatable disk recording medium and a negative pressure which is rotatable and is mounted at a tip end thereof at a position facing the disk recording medium. The negative pressure floating head slider is formed on the air bearing surface of the slider, and is formed following the air introduction part located on the air inflow end side, and a rotary actuator having the floating head slider. A cross rail, a pair of side rails extending in the longitudinal direction of the slider formed following the cross rail, and a first groove formed in a region surrounded by the cross rail and the side rail. And a magnetic transducer provided on the air outflow end side of the slider, wherein the negative pressure slider is A second groove provided on an air inflow end side of the ida so as to separate the air introduction portion;
And a slit provided so as to separate the cross rail. The width of a portion where the air introduction section is connected to the cross rail is determined by the side rail. The width is narrower than the width of the portion connected to the cross rail. With this configuration, the adhesive force due to the grease floating in the magnetic disk device can be reduced, and the reliability can be improved.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A negative pressure slider according to an embodiment of the present invention will be described below with reference to FIGS.
First, the configuration of the groove of the negative pressure slider according to one embodiment of the present invention will be described with reference to FIG. FIG. 1 is a plan view of a negative pressure slider according to an embodiment of the present invention.

FIG. 1 shows a state where the negative pressure slider 100 is viewed from the side facing the disk recording medium. The surface shown in FIG. 1 is the air bearing surface of the slider 100 with respect to the disk recording medium.

The slider 100 has an air inlet end Ein at one of its longitudinal ends and an air outlet end Ein at the other end.
out. The air flow generated with the rotation of the disk recording medium is the air inflow end Ein of the slider 100.
To the air outflow end Eout.

The rear side of the slider 100 is fixed to the gimbal portion at the tip of the suspension at the tip of the carriage of the rotary actuator. The suspension has a shape extending in the direction of the air inflow end Ein in FIG.

In this embodiment, the slider 100 has a length L of 2.05 mm, a width W of 1.6 mm, and a thickness T of 0.3 mm.

On the air bearing surface of the slider 100, a pair of side rails 110 and 112 and a cross rail 120,
122 and an air introduction portion 130 having a tapered shape,
132, a first groove 140, a slit 150, a second groove 160, and a center rail 170.

On the air inflow end Ein side of the slider 100,
Air introduction parts 130 and 132 are provided. The air introduction portions 130 and 132 are tapered as described later with reference to FIG. Tapered air inlets 130, 1
32 has a length L1 in the longitudinal direction of 0.2 mm, the inclination of the tapered portion is about 0.7 °, and a minute tapered portion is formed. The air inflow ends Ein of the air introduction portions 130 and 132 are 3 μm larger than the surfaces of the cross rails 120 and 122.
m lower. The air introduction parts 130 and 132 are for introducing air to the air bearing surface of the slider 100. The air introduction portions 130 and 132 may have a stepped shape instead of the tapered shape.

A second groove 160 is provided so as to separate the air introduction portions 130 and 132. Second groove 1
Reference numeral 60 denotes a cross rail 1 as described later with reference to FIG.
It is lower than the planes 20 and 122 and is tapered. Cross rail 12 of second groove 160
0, 122, the cross rails 120,
The height is 6 μm lower than that of the surface 122. Further, the second groove 160 has a tapered shape parallel to the air introduction portions 130 and 132. Therefore, the air inflow end Ein side of the second groove 160 is 9 μm lower than the surfaces of the cross rails 120 and 122.

The air introduction portions 130 and 132 have inclined surfaces 134 and 136 at positions facing the second groove 160 side. The inclination θ1 of the inclined surfaces 134 and 136 is 25
There is as ゜. In the present embodiment, the yaw angle of the magnetic disk drive on which the negative pressure slider 100 is mounted is +
Those that change between 5 ° and -17 ° are used. That is, the inclination θ1 of the inclined surfaces 134 and 136 is larger than the yaw angle. Also, the width W2 of the portion where the air introduction portions 130 and 132 are connected to the cross rails 120 and 122 is
0.25 mm (= 250 μm).

Following the air introduction sections 130 and 132, cross rails 120 and 122 are provided. The width L2 of the cross rails 120 and 122 is 0.15 mm (= 150
μm). Since the width of the cross rails 120 and 122 is not constant, the width L2 here is the width at the narrowest position.

A slit 150 is provided so as to divide the cross rails 120 and 122. Slit 15
The width W1 of 0 is 0.15 mm (= 150 μm).
The air flows into the groove 140 from the air inflow end Ein through the slit 150.

Following the cross rails 120 and 122, the side rails 11 extending in the longitudinal direction of the slider 100
0, 112 are provided. Side rail 110,1
Reference numeral 12 is the same height as the cross rails 120 and 122 and is formed up to the air outflow end Eout. The side rail 110 is located on the outer peripheral side of the disk recording medium when facing the disk recording medium, and the side rail 112 is located on the inner peripheral side of the disk recording medium. Side rails 110 and 112 are cross rails 12
The width W3 of the portion connected to 0,122 is 0.35 mm
(= 350 μm). That is, the air introduction units 130, 1
The width W2 of the portion where the cross rail 32 is connected to the cross rails 120 and 122 is such that the side rails 110 and 112 are
The width is smaller than the width W3 of the portion connected to the first and second parts 20 and 122. The width W4 of the narrowest part of each of the side rails 110 and 112 is 0.1 mm (= 100 μm).

In the area surrounded by the side rails 110 and 112 and the cross rails 120 and 122, the slider 100
The first groove 140 of the air bearing surface is formed. The depth of the first groove 140 is 6 μm. The outside of each of the side rails 110 and 112 is the first groove 1.
It is cut to the same depth as 40.

At the center of the first groove 140, a center rail 170 is formed. Center rail 170
Are the side rails 110 and 112 and the cross rail 12
It is the same height as 0,122. In the vicinity of the air outflow end Eout of the center rail 170, a magnetic transducer 180 for recording and reproducing information on a disk recording medium is provided.

Side rails 110 and 112 formed on the air bearing surface of the slider 100, and cross rails 120 and 112
122, air introduction parts 130, 132 and center rail 1
With the position where 70 is left as a mask, the first groove 140 is formed by a method such as ion milling and etching.
The slit 150, the second groove 160, and both sides of the side rails 110 and 112 are cut off. In addition,
The tapered shapes of the air introduction portions 130 and 132 are formed in advance before processing by ion milling or the like.

Next, the pressure distribution in the XX section of FIG. 1 will be described with reference to FIG. FIG. 2 is a pressure distribution diagram along a side rail of a negative pressure slider according to an embodiment of the present invention.

FIG. 2 shows the negative pressure slider 100 shown in FIG. 1 when the negative pressure slider 100 having the structure of the air bearing surface shown in FIG. 1 is levitated on a magnetic disk having a diameter of 95 mm rotating at 7200 rpm. The pressure distribution in the XX section is shown. The air that has entered from the air inflow end Ein is compressed by the air introduction section 132 and is then pressurized, then temporarily reduced in pressure on the side rail 112, slightly increased in pressure near the air outflow end, and finally the air outflow end Eout.
To reach.

Here, the maximum pressure in the air introducing section 132 differs depending on the position of the negative pressure slider in the radial direction of the magnetic disk. For example, at the inner circumferential position of a magnetic disk having a radius of 20 mm, the gauge pressure is about 1.1 kgf / cm ^2.
(≒ about 10.8 × 10 ⁴ Pa), and about 1.2 kgf / cm at the center position of the magnetic disk having a radius of 33 mm.
² (≒ about 11.8 × 10 ⁴ Pa) and a radius of 4
At the outer circumference of a 4 mm magnetic disk, about 1.4 kgf /
cm ² (≒ about 13.7 × 10 ⁴ Pa). In other words, the pressure is increased to a considerable pressure, although it differs at the radial position of the magnetic disk.

Here, the behavior of the mist such as grease when the pressure distribution shown in FIG. 2 is shown will be described with reference to FIG. FIG. 3 is an explanatory diagram of the behavior of the negative pressure slider according to an embodiment of the present invention when there is a mistake along the side rail. FIG. 3 shows the negative pressure slider 1 shown in FIG. 1 in a state where the negative pressure slider is floating on the rotating magnetic disk.
The state of the section XX of 00 is schematically shown.

When the magnetic disk drive is operated for a long time, the temperature inside the drive rises, and grease used as a lubricant for bearings and the like used in the drive leaks into the drive and becomes a mist. , Filling into the device. The mist-like grease Gm floating in the apparatus enters the gap between the negative pressure slider 100 and the magnetic disk 220 due to the airflow V generated by the rotation of the magnetic disk 220, and has the largest pressure gradient and the stopping point of the velocity. Air introduction part 1 with
At first, it adheres to 32. In the air introduction section 132, the air flow V
Poiseuille flow occurs in opposition to the Couette flow due to When the flow velocity of the couette flow becomes equal to the flow velocity of the Poiseuille flow, a stop point of the speed occurs, and mist-like grease Gm adheres to this stop point.

The mist-like grease adhering to the air introduction part 132 accumulates to a certain amount in the air introduction part 132 to become a grease droplet Gd, and then from the air outflow end Eout via the side rail 112. It is discharged into the atmosphere along the flow of air. Therefore, the air introduction sections 132, 13
The grease picked up in 4 does not accumulate in the first groove 140.

Next, the pressure distribution in the YY section of FIG. 1 will be described with reference to FIG. FIG. 4 is a pressure distribution diagram along the groove of the negative pressure slider according to one embodiment of the present invention.

FIG. 4 shows the negative pressure slider 100 shown in FIG. 1 when the negative pressure slider 100 having the structure of the air bearing surface shown in FIG. 1 is floated on a 95 mm-diameter magnetic disk rotating at 7200 rpm. The pressure distribution in the YY section is shown.

In the negative pressure slider 100 shown in FIG. 1, a second groove 160 deeper than the first groove 140 is formed between the air inflow end Ein and the cross rails 120 and 122. Therefore, the air is not significantly pressurized before the first groove 140 that generates the negative pressure. For example,
At the inner circumferential position of the magnetic disk having a radius of 20 mm, the gauge pressure is about 0.2 kgf / cm ² (≒ about 1.9 × 10 ⁴ Pa), and at the inner circumferential position of the magnetic disk having a radius of 33 mm, about 0.2 kgf / cm ² .
3 kgf / cm ² (≒ about 2.9 × 10 ⁴ Pa), and about 0.45 k
The pressure is increased only by about gf / cm ² (approximately 4.4 × 10 ⁴ Pa). This is about 18% to 30% larger than the case where there is a tapered portion like the XX section.

Here, with reference to FIG. 5, a description will be given of the behavior of the grease or the like when the pressure distribution shown in FIG. 4 is shown. FIG. 5 is an explanatory diagram of the behavior of the mist along the groove of the negative pressure slider according to one embodiment of the present invention. FIG.
Y-Y of the negative pressure slider 100 shown in FIG. 1 in a state where the negative pressure slider is flying above the rotating magnetic disk.
The state of the cross section is schematically shown.

The mist-like grease Gm floating in the magnetic disk drive is moved by the airflow accompanying the rotation of the magnetic disk 220 to the negative pressure slider 100 and the magnetic disk 22.
0, but in the YY section, unlike the XX section, the tapered air introduction section 1 having a large pressure gradient.
Instead of 32, a second groove 160 is formed, the speed stop portion is small, and a large amount of mist-like grease Gm does not accumulate. The grease Gm first collects near the boundary between the second groove 160 and the cross rail 122 where the speed is relatively slow. The behavior of the grease Gm collected here will be described with reference to FIG.

FIG. 6 shows the second groove 160 and the cross rail 122 in the negative pressure slider according to one embodiment of the present invention.
FIG. 4 is an explanatory diagram of the behavior of grease collected near the boundary of FIG.

The mist-like grease Gm attached to the second groove 160 does not largely accumulate, and proceeds along the air flow. That is, the grease Gm gathered near the second groove 160 and the cross rails 120 and 122 is
It moves in the direction of the slit 150 as it is, and the slit 15
0 flows toward the first groove 140. The grease Gm that has flowed into the first groove 140 is
Without exiting to the air outflow end Eout.

Here, if there is no slit 150, the second
After the grease has adhered at the boundary between the groove 160 and the cross rails 120 and 122, there is no place for escape, so that the grease accumulates and becomes a large lump of grease.
2 and the position where the negative pressure is maximum near the boundary between the cross rails 120 and 122 and the first groove 140, that is,
Grease adheres and accumulates on the stop part of the speed. The grease mass adhering to the groove where the negative pressure, which is the stop portion of the speed, where the negative pressure is maximum no longer moves, and stays there when floating.
When the device stops and the negative pressure slider and the magnetic disk stop contacting, the grease accumulated in the first groove 140 is
It spreads in the narrow gap between the negative pressure slider and the magnetic disk and forms a meniscus, resulting in a large adhesive force.
Therefore, the slits 150 provided in the cross rails 120 and 122 are extremely important so as not to obstruct the flow of air and not to form a large lump of grease.

In the present embodiment, the second rail 160 is provided between the air inflow end Ein and the cross rails 120 and 122 instead of the conventional tapered part, so that the cross rail 1 is provided.
By minimizing the pressure rise before 20, 122, it became possible to minimize the adhesion of grease.

Further, by providing the slits 150 in the cross rails 120 and 122, the grease can reach the air outflow end Eout via the second groove 160, the slit 150 and the first groove 140 and be discharged. . Therefore, the first groove 140 or the second groove 16
Grease does not accumulate on the magnetic disk, and even when the negative pressure slider is in contact with the magnetic disk when the apparatus is stopped, the grease does not ooze out and a meniscus is not formed between the negative pressure slider and the magnetic disk. Can be reduced.

The width L of the cross rails 120 and 122
2 is thinner, the air is not pressurized by the cross rails 120 and 122, so that the maximum pressure in the YY cross section can be reduced,
Speed stagnation can be reduced. For example, when a magnetic disk having a diameter of 95 mm rotates at 7200 rpm, the maximum pressure at the outer peripheral position of the magnetic disk is 0.5 kgf / cm ^2.
In order not to exceed, the cross rail width L2 is 15
It is desirable that the thickness be 0 μm or less. Maximum pressure 0.5k
If the value exceeds gf / cm ² , a stagnation portion of the air flow tends to be formed, and as a result, a grease lump stays at that position.

The slit width W1 is preferably 150 μm or less, since if the width is too wide, a negative pressure required to make the flying height uniform cannot be secured. The required negative pressure is about 2 gf on the inner circumference and about 3 gf on the outer circumference. On the other hand, if the width is too narrow, the cross-sectional area of the slit becomes small, and the change in the flying height due to the variation in processing becomes large.
μm or more is preferred. If the cross-sectional shape of the slit can be made rectangular, the slit width can be further reduced.
However, it is difficult to form a corner at a right angle by general ion milling, so that the cross-sectional shape of the slit is close to a semicircular shape. Therefore,
When the slit width becomes narrow, the depth of the slit also changes,
It becomes shallower than the desired depth of 6 μm. As a result, the cross-sectional area decreases, and the change in the flying height increases.

The negative pressure slider 10 according to the present embodiment
0 side rails 110 and 112 and cross rail 12
0, 122 and the center rail 170 are all at the same height, and the slit 150 and the second groove 160 of the negative pressure slider 100 can be formed simultaneously with the formation of the first groove 140 that generates a negative pressure. The entire air bearing surface can be formed by ion milling, and workability is improved.

Further, in general, when the length of the tapered portion of the air introduction portion changes due to processing variations, the flying height of the negative pressure slider greatly changes. If the flying height changes in a direction in which the flying height decreases, contact between the negative pressure slider and the magnetic disk surface or the like occurs, and the reliability of the magnetic disk device decreases.
Further, if the flying height changes in a direction in which the flying height increases, recording and reproduction cannot be performed.

The reason for this is that, conventionally, when the length of the tapered portion changes due to the large area of the tapered portion occupying the entire flying surface, the area of the tapered portion changes, and the flying height of the negative pressure slider changes. Was thought to be.
However, according to the research by the inventors, it has been clarified that the cause of a large change in the flying height is not only the effect of the area of the tapered portion. That is, in the conventional negative pressure slider, the air introduction portions 130 and 132 are
The width W2 of the portion connected to the side rail 122 is
The width W3 of the portion where 0, 112 is connected to the cross rails 120, 122 is wider. In such a case, the airflow compressed by the tapered air introduction portions 130 and 132 crosses the cross rails 120 and 122 and
It has been clarified that the influence of the air flow compressed in the tapered portion on the negative pressure increases by increasing the ratio of the air flowing directly into the first groove 140. Therefore, in such a conventional structure, the length L1
Changes due to processing variations, the first groove 14
The magnitude of the negative pressure generated at 0 changes, and the flying height changes.

Therefore, in this embodiment, first,
A second groove 160 is formed between the tapered air introduction sections 130 and 132. Thus, the area of the tapered portion is reduced, so that the change in the flying height is reduced even if the length L1 of the tapered portion changes due to processing variations. Second, the air introduction units 130, 13
2 is a width W of a portion connected to the cross rails 120 and 122.
2 is the side rail 110, 112 is the cross rail 12
The width is smaller than the width W3 of the portion connected to 0,122. Thereby, the tapered air introduction portions 130 and 132
The magnitude of the negative pressure generated in the first groove 140 is reduced even when the length L1 of the tapered portion changes due to the variation in processing by reducing the ratio of the air flow compressed in the first groove 140 flowing into the first groove 140. Does not change, and the flying height does not change.

Here, specifically, as shown in FIG. 1, a second groove 160 is formed between the tapered air introducing portions 130 and 132, and the air introducing portion 1 is formed.
The negative pressure slider 100 having a structure in which the width W2 of a portion where the cross rails 30 and 132 are connected to the cross rails 120 and 122 is smaller than the width W 3 of a portion where the side rails 110 and 112 are connected to the cross rails 120 and 122 was studied. . This negative pressure slider 100 is moved at an air flow velocity of 34 m.
/ S (equivalent to the speed at the outer periphery of a 95 mm diameter magnetic disk rotating at 7200 rpm), the length L1 of the tapered air introduction portions 130 and 132 is 200 μm
In this case, the flying height is 50 nm. On the other hand, the length L1 of the air introduction portions 130 and 132 is set to 25 μm (12.
Even if the length was increased by 5% (working variation of 5%), the flying height did not change at all. Further, even when the length L1 of the air introduction portions 130 and 132 is reduced by 25 μm (12.5% processing variation) and the length L1 is set to 175 μm, the flying height is reduced by 1.3 nm (2.6%). Was reduced).

On the other hand, as a comparative example, a negative pressure slider having a tapered air introducing portion 130 and an air introducing portion 132 continuous and having no second groove 160 was examined under the same conditions. The length L1 of the air introduction section is 25 μ
m, the flying height is 6.2 nm (12.4%)
Rose. It was also found that when the length L1 of the air introduction portion was reduced by 25 μm, the flying height was reduced by 6.8 nm (13.6% reduction in flying height).

That is, in the present embodiment, the second groove 160 is formed between the tapered air introduction portions 130 and 132, and the air introduction portions 130 and 132 are connected to the cross rails 120 and 122. By making the width W2 of the portion smaller than the width W3 of the portion where the side rails 110 and 112 are connected to the cross rails 120 and 122, even if the length L1 of the tapered portion changes due to processing variations.
The change in the flying height could be reduced.

Next, a state where the negative pressure slider according to one embodiment of the present invention is mounted on a magnetic disk drive will be described with reference to FIG. FIG. 7 is a plan view of a magnetic disk drive using a negative pressure slider according to one embodiment of the present invention.

3.5 inch magnetic disk drive 200
Is a spindle 210 rotating at a rotation speed of 7200 rpm.
, A disk recording medium 220 having a diameter of 3.5 inches and a rotary actuator 230.

The rotary actuator 230 includes a rotating carriage 240, a suspension 250 attached to the tip of the carriage 240, and a suspension 250.
And a negative pressure slider 100 attached to the tip of the slider. The negative pressure slider 100 has the configuration shown in FIG.

The negative pressure slider 100 has a suspension 250 such that the air bearing surface, such as the side rails shown in FIG.
Attach to the tip.

When the disk recording medium 220 is 7200 rpm
By rotating at m, an airflow V is generated in the circumferential direction of 220 of the disk recording medium. Negative pressure slider 10
The rotary actuator 230 to which the “0” is attached performs an oscillating motion in order to position the slider 100 on a predetermined track among a plurality of tracks formed from the inner circumference to the outer circumference of the disk recording medium 220. The swing motion of the rotary actuator 230 causes the slider 100
The angle between the direction in which air flows in along the circumference of the disk recording medium 220 and the longitudinal direction of the slider 100 changes. This angle is defined as a yaw angle, and the sign of the yaw angle in the direction in which air flows in from the inner peripheral side of the disk recording medium 100 with respect to the longitudinal direction of the slider 100 is expressed as positive. The magnetic disk device 200 according to the present embodiment has a yaw angle of
It changes within a range of approximately + 5 ° to -17 °.

The slider 100 includes a suspension 250
Is pressed against the disk recording medium 220 with a force of 1.5 gf. The air flow generated by the rotation of the disk recording medium 220 enters between the slider 100 and the disk recording medium 220, so that the slider 100 flies above the disk recording medium 220 with a flying height of several tens of nm.

The slider 100 is a rotary actuator 2
30, approximately 20 to 44 on the disk recording medium 220.
It is positioned accurately at any radial position of mm. Air outflow end Eout of center rail 170 of slider 100
Recording and reproduction of information with respect to the disk recording medium 220 are performed by the magnetic transducer 180 mounted on the side.

By using the negative pressure slider according to the present embodiment, the adhesive force due to the grease floating in the magnetic disk device can be reduced, and a highly reliable magnetic disk device can be realized.

In order to make it difficult for the negative pressure slider to adhere to the surface of the magnetic disk, the surface of the magnetic disk is conventionally provided with irregularities. On the other hand, by using the negative pressure slider according to the present embodiment, the adhesive force of the negative pressure slider can be reduced, so that the surface of the magnetic disk can be smoothed. As a result, the flying height can be made smaller than before, so that the recording density in the magnetic disk device can be improved and high-density recording can be performed.

As described above, according to the present embodiment, by providing the second groove 160 between the air inflow end Ein and the cross rails 120 and 122, the pressure increase before the cross rails 120 and 122 can be reduced. By keeping it to a minimum, it is possible to minimize the adhesion of grease.

Further, by providing the slits 150 in the cross rails 120 and 122, the grease passes through the second groove 160, the slit 150 and the first groove 140,
Since the air reaches the air outflow end Eout and can be discharged, no grease is accumulated in the first groove 140 or the second groove 160, and even when the negative pressure slider is in contact with the magnetic disk when the apparatus is stopped. Since the grease does not ooze out and form a meniscus between the negative pressure slider and the magnetic disk, the adhesive strength can be reduced.

Since the depth of the second groove 160 is equal to or greater than the depth of the first groove 140, the cross rail 12
Since the air is not pressurized on the air inflow side at 0,122, the maximum pressure can be reduced, the stagnation of the speed can be reduced, and the accumulation of the grease can be prevented.

Further, by setting the width L2 of the cross rails 120 and 122 to 150 μm or less, the air is not pressurized by the cross rails 120 and 122, so that the maximum pressure in the YY cross section can be reduced, and the speed stagnation is reduced. It is possible to prevent the grease lump from stagnating.

By setting the slit width W1 to 150 μm or less, it is possible to secure a negative pressure required to make the flying height uniform, and by setting the slit width to 50 μm or more, the floating due to processing variation is increased. Changes in volume can be reduced.

The negative pressure slider 10 according to the present embodiment
0 side rails 110 and 112 and cross rail 12
0, 122 and the center rail 170 are all at the same height, and the slit 150 and the second groove 160 of the negative pressure slider 100 can be formed simultaneously with the formation of the first groove 140 that generates a negative pressure. The entire air bearing surface can be formed by ion milling, and workability is improved.

Further, in the present embodiment, the second groove 160 is provided between the tapered air introduction portions 130 and 132.
Is formed to reduce the area of the tapered portion so that the change in the flying height is reduced even if the length L1 of the tapered portion changes due to processing variations. Further, the width W2 of the portion where the air introduction portions 130 and 132 are connected to the cross rails 120 and 122 is determined by the side rails 110 and 112.
Is the width W3 of the part connected to the cross rails 120 and 122.
By making it narrower, the tapered air inlet 13
The negative pressure generated in the first groove portion 140 is reduced even if the length L1 of the tapered portion changes due to the variation in processing by reducing the ratio of the air flow compressed in the first groove portion 140 to the first groove portion 140. And the flying height does not change.

Further, by using the negative pressure slider according to the present embodiment, the adhesive force due to the grease floating in the magnetic disk device can be reduced, and a highly reliable magnetic disk device can be realized.

Further, since the adhesive force of the negative pressure slider can be reduced, the surface of the magnetic disk can be smoothed, and the flying height can be made smaller than before, so that the recording density in the magnetic disk device can be improved, and Becomes possible.

Next, a negative pressure slider according to a second embodiment of the present invention will be described with reference to FIG. FIG. 8 is a plan view of a negative pressure slider according to the second embodiment of the present invention.

On the air bearing surface of the slider 100A, a pair of side rails 110A and 112A,
20A, 122A, air introduction portions 130A, 132A having a tapered shape, a first groove 140A, a slit 150A, and a second groove 160A. The difference from the negative pressure slider shown in FIG. 1 is that the center rail 170 shown in FIG.
0 is provided on the side of the air outflow end Eout of the side rail 112A. Even if you lose the center rail,
In order to make the area of the air bearing the same as the example of FIG. 1, the shapes of the side rails 110A and 112A are changed.

The surfaces of the cross rails 120A and 122A that are in contact with the second groove 160A on the air inflow end Ein side are inclined surfaces 124A and 126A. by this,
Mist-shaped grease Gm adhered to second groove 160A
To the slit 15 via the inclined surfaces 124A and 126A.
It is easy to move in the direction of 0A.

Also in this embodiment, the adhesion of grease can be suppressed to a minimum, and the adhesive force between the negative pressure slider and the magnetic disk can be reduced.

Further, even if the length L1 of the tapered portion changes due to processing variations, the magnitude of the negative pressure generated in the first groove 140A does not change, and the flying height does not change.

Further, it is possible to prevent the grease or the like adhering to the second groove 160A from sticking and stopping.

Next, a negative pressure slider according to a third embodiment of the present invention will be described with reference to FIG. FIG. 9 is a plan view of a negative pressure slider according to the third embodiment of the present invention.

On the air bearing surface of the slider 100B, a pair of side rails 110B and 112B,
20B, 122B, air introducing portions 130B, 132B having a tapered shape, a first groove 140B, a slit 150B, a second groove 160B, and a center rail 170B. The difference from the negative pressure slider shown in FIG. 1 is that the rear portions of the side rails 110B and 112B do not extend to the air outflow end Eout, and further, inclined end portions 114B and 116B are provided. Further, even if the overall length of the side rails 110B and 112B is reduced, the shape of the side rails 110B and 112B is changed so that the area of the air bearing is the same as the example of FIG. When the negative pressure slider 100B inclines while floating on the magnetic disk, as shown in FIG.
Since the air outflow end side of the negative pressure slider is closest to the magnetic disk surface, the side rails located on both sides of the negative pressure slider on the air outflow end side come into contact with the magnetic disk surface. On the other hand, the rear of the side rails 110B and 112B does not extend to the air outflow end Eout, and the inclined ends 114B and 116B are provided. When the rail does not contact the magnetic disk surface, the flying height of the negative pressure slider can be further reduced.

The grease adhering to the air introducing portions 132B and 134B adheres to the rear ends of the side rails via the side rails 110B and 112B. However, the amount of grease adhering to the side rails 110B and 112B is relatively smaller than the amount of grease adhering to the first groove 140B where the maximum negative pressure is generated, and the speed is not completely stagnant, so that the grease relatively moves. The effect on the adhesive force at the time of stoppage is small compared to the case where the adhesive force adheres to the negative pressure portion.

The surfaces of the cross rails 120B and 122B that are in contact with the second groove 160B on the air inflow end Ein side are inclined surfaces 124B and 126B. by this,
Mist-shaped grease Gm adhered to second groove 160B
Through slits 124B and 126B.
It is easy to move in the direction of 0.

Also in this embodiment, the adhesion of grease can be minimized, and the adhesive force between the negative pressure slider and the magnetic disk can be reduced.

Further, even if the length L1 of the tapered portion changes due to processing variations, the magnitude of the negative pressure generated in the first groove 140B does not change, and the flying height does not change.

Further, it is possible to prevent the grease or the like adhering to the second groove 160B from sticking and stopping.

Further, even if the negative pressure slider is tilted, it is difficult to contact the magnetic disk surface, so that the flying height can be further reduced.

[0088]

As described above, according to the present invention,
An air inlet for reducing the accumulation of lubricant in the groove of the air bearing surface of the slider in the negative pressure slider, reducing the increase in the adhesive force between the slider and the disk recording medium, and generating a negative pressure due to processing variations. Even if the length changes, variation in the flying height can be reduced. Further, the reliability of the magnetic disk drive using the negative pressure slider can be improved.

[Brief description of the drawings]

FIG. 1 is a plan view of a negative pressure slider according to an embodiment of the present invention.

FIG. 2 is a pressure distribution diagram along a side rail of a negative pressure slider according to an embodiment of the present invention.

FIG. 3 is an explanatory diagram of a behavior of a negative pressure slider according to an embodiment of the present invention when there is a mistake along a side rail.

FIG. 4 is a pressure distribution diagram along a groove of a negative pressure slider according to an embodiment of the present invention.

FIG. 5 is an explanatory diagram of the behavior of the mist along the groove of the negative pressure slider according to the embodiment of the present invention.

FIG. 6 is an explanatory diagram of the behavior of grease collected near the boundary between the second groove 160 and the cross rail 122 in the negative pressure slider according to the embodiment of the present invention.

FIG. 7 is a plan view of a magnetic disk drive using a negative pressure slider according to one embodiment of the present invention.

FIG. 8 is a plan view of a negative pressure slider according to a second embodiment of the present invention.

FIG. 9 is a plan view of a negative pressure slider according to a third embodiment of the present invention.

[Explanation of symbols]

100: negative pressure slider, 112, 114: side rail 120, 122b: cross rail, 130, 132 ...
Air introduction part 140: first groove, 150: slit 160: second groove, 170: center rail 180: magnetic head, Ein: air inflow end Eout: air outflow end

 ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Nao Yonekawa 2880 Kozu, Kozuhara-shi, Kanagawa Prefecture, Ltd.Storage Systems Division, Hitachi, Ltd. System Division

Claims (4)

[Claims] 1. An air introduction portion formed on an air bearing surface of a slider and located on an air inflow end side, a cross rail formed following the air introduction portion, and the cross rail formed following the cross rail. A pair of side rails extending in the longitudinal direction of the slider, a first groove formed in a region surrounded by these cross rails and the side rails, and a magnetic transducer provided on the air outflow end side of the slider. A second groove portion provided on the air inflow end side of the slider so as to separate the air introduction portion; connecting the first groove portion and the second groove portion; A slit provided so as to separate the cross rail, wherein a width of a portion where the air introduction portion is connected to the cross rail is connected to the side rail and the cross rail. A negative pressure slider is characterized in that narrower than the width of the portion that. 2. The negative pressure slider according to claim 1, wherein a depth of said second groove is greater than a depth of said first groove. 3. The negative pressure slider according to claim 1, wherein the maximum width of the cross rail is 150 μm or less. 4. A disk recording medium comprising: a rotatable disk recording medium; and a rotary actuator having a negative pressure floating head slider rotatable and mounted at a position opposite to the disk recording medium at the end thereof. The negative pressure floating head slider is formed on an air bearing surface of the slider, and has an air introduction portion located on an air inflow end side;
A cross rail formed following the air introduction portion, a pair of side rails formed in a longitudinal direction of the slider formed following the cross rail, and a region surrounded by the cross rail and the side rail. A magnetic disk drive comprising: a first groove formed in the slider; and a magnetic transducer provided on an air outflow end side of the slider, wherein the negative pressure slider has an air introduction section on an air inflow end side of the slider. A second groove provided to separate the cross rail, and a slit provided to connect the first groove and the second groove and to separate the cross rail. A width of a portion where the portion is connected to the cross rail is smaller than a width of a portion where the side rail is connected to the cross rail. apparatus