JP2000322722A - Slider of disk recording and reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slider having an air bearing surface which is small in fluctuation in a flying height even when the flying height is minimized and further even when a changing speed (seek speed) of a skew angle is increased. SOLUTION: The slider 3 of the disk recording and reproducing device has a first pad 31 formed on an inflow end 21 side of floating surfaces, a second pad 32 formed on the inflow end 21 side of the floating surfaces and a third pad 33 formed on the outflow end 22 side of the floating surfaces. At least one of the first pad 31, the second pad 32 and the third pad 33 has first ridge lines 71, 72 and 73 formed on the inflow end side. The first ridge lines 71, 72 and 73 includes curves 71, 72 and 73 having projecting parts on the inflow end side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slider used for a storage device such as a hard disk device, and more particularly to a slider used for a storage device such as a hard disk device having a rotary actuator.

[0002]

2. Description of the Related Art Conventionally, a hard disk drive (hereinafter referred to as "HD
D ") includes a head for recording and reproducing data on both sides of a disk as a recording medium. HD
In D, the head is mounted on a support made of a ceramic material or the like called a slider, and is supported in a state of flying above the data recording surface of the disk at a predetermined interval.

[0003] The HDD includes one or several disks. The disks are stacked on the main shaft at a distance so that they do not touch each other. The surface of each disk is apparently identical. However, in practice, each surface is divided into pad sections called tracks, in which data is stored. These trucks are arranged as concentric circles like tree rings. The compact disk has the same tracks as the disks in the HDD. Each track of an HDD or compact disc essentially replaces the groove of a 45-turn record.
Each track in the HDD is further divided into sectors, which are just sections in one concentric track.

[0004] Disks are made of various materials such as metal, resin and glass. On resin disks such as those used for CDs, lasers store and retrieve data. On metal disks, data is stored and retrieved by electromagnets commonly known as transformers.

In order to store data on a magnetic disk, the surface of the disk is magnetized using a small ceramic block generally called a slider. The slider incorporates a magnetic transducer, which is a so-called write head. More specifically, the slider with the built-in write head is a few hundred nanometers (nm) from the disk surface.
Floating to a height of several tens of nanometers (nm) from above, the head is excited into several states and magnetizes the underlying tracks to correspond to the data.

In order to retrieve data stored on a magnetic disk, a slider containing a read head is floated on the disk. At this time, a current is induced in the read head by the magnetized portion on the track. By analyzing the current output from the read head, the computer system can reproduce and use the data stored on the magnetic disk. Some h
While DD uses separate read and write heads, most modern HDDs use a transducer that performs both read and write operations. Recently, a magnetoresistive element or an inductance element has been used as a read head.

[0007] Like a record, both sides of the disc are usually used to store data or other information necessary for operation of the HDD. Because the disks are stacked and spaced apart from each other, each stacked disk has its own read / write head on both the front and back surfaces. This is as if a stereo with record hands on each side could play both sides of the record at the same time.

There are two types of HDDs having a rotary actuator and a linear actuator. The rotary actuator has an actuator arm similar to the tone arm of a record player. Like a tone arm, its actuator arm rotates so that a slider containing a read / write head can move to positions above various tracks on the disk.

Thus, the read / write head is:
It can be used to magnetize tracks on the surface of a disk to a pattern corresponding to data, or to detect a magnetized pattern on a track. For example, if the required data is stored on two different tracks of a disk, the actuator arm may move from one track to the other to read what is magnetically representative of the data. Rotate to. The present invention relates to a rotary actuator HDD.

[0010] Linear actuators also have a similar actuator arm, but the movement of position is performed by linear movement rather than rotation.

[0011] The actuator arm of the HDD has a slider attached to the tip thereof, and has a built-in read / write head therein. A pad is fixed to the slider. As the disk rotates, air is drawn between the pad and the disk surface, thereby applying pressure to keep the head away from the disk. The head then floats on the rotating disk as described above. The flying height is the thickness of the air lubrication film, that is, the distance between the disk surface and the head.

Thus, the pad forms an air bearing surface (ABS) and forms and maintains a self-pressurizing air lubrication film between the head and the disk storage surface. This film eliminates friction and wear that occurs when the head and the disk come into mechanical contact during disk rotation.

[0013] Conventional ABS designs basically consist of two tapered pads known as tapered flat sliders. The two-pad tapered flat configuration typically has two or more flat pads, each with a tapered tip. The pads are extended with a tapered tip oriented in the direction of rotation of the disk surface.

Such a design works well in a linear actuator HDD because the air between the disk and the slider basically flows in one direction along the length of the pad. Stated another way, such a design requires that the slider be positioned relative to the disk such that viscously drawn air under the slider flows from the front of the slider to the rear along a longitudinal axis parallel to the pad. Can be said to work well. The concept of tapered flat design dates back to the era of relatively slow access speed, large diameter files using linear actuators.

Today's HDDs are significantly different from large diameter HDDs using linear actuators.
Current files are very small and data access is fast. Currently, HDDs are equipped with rotary actuators to process disks of 5.25 inches, 3.50 inches, 2.50 inches, 1.80 inches in diameter and to obtain fast access speeds. Due mainly to the use of rotary actuators, the airflow under the slider is no longer essentially unidirectional,
It extends at various angles with respect to the longitudinal axis of the slider.

In addition, the high-speed search operation of the actuator being accessed causes the flow between the head and the disk to be tilted. Therefore, in a recent rotary actuator HDD, the airflow is no longer considered to move from the front to the rear of the slider or slightly deviate therefrom.

The angle of the airflow relative to the vertical axis of the slider is called the skew angle. The tilt angle is positive when the actuator arm is positioned so that airflow hits the outer edge or outside of the slider. Actuator so that it touches the inner end of the slider or the hub
When the arm is located, the skew angle is negative.
The tapered flat design results in extreme drop in floating altitude at high positive or negative skew angles and fast access speeds because the slider is designed for linear actuators rather than rotary actuators. Cheap.

Also, due to the twist of the airflow, the flying height is not constant under all pads due to the rotation of the slider. Turning the slider is analogous to tilting the aircraft as the plane changes direction. That is,
It is a movement that raises one wing and lowers the other wing.
In the HDD, a positive rotation occurs when the outer pad moves away from the disk surface, and a negative rotation occurs when the outer pad approaches the disk surface.

In the HDD, the flying height of the slider is an important parameter that needs to be controlled. As the floating altitude increases, the signal amplitude decreases and the signal-to-noise ratio decreases, thus increasing the error rate. When the flying height decreases, the possibility that the head comes into contact with the disk surface increases, and if it does, the wear of both the head and the disk surface increases, the reliability decreases, and the HDD may be damaged. Extreme contact with the disk surface that could cause a failure is called a crash, and the data becomes unplayable.

Controlling the rotation of the slider is also important.
When the end portion of the slider is lowered by rotation, the possibility that the head comes into contact with the disk surface increases. When rotation occurs to lift one end of the slider, the distance of the read / write head from the disk surface increases,
As the floating altitude becomes higher, it causes a data error as well as a data error. The adverse effects of such rotation are exacerbated when the read / write head is mounted on its raised end.

A conventional technique is disclosed in Japanese Patent Application Laid-Open No. 8-255331. In Japanese Patent Application Laid-Open No. 8-255331, the rear end of the tapered portion of the pad is configured so as to be located at a position where the pad width decreases, so that the processing tolerance hardly affects the flying characteristics.

[0022]

However, as the recording density of HDDs has increased in recent years, the flying height has been minimized, and the speed of change (seek speed) of the skew angle has been increased.

In the conventional configuration disclosed in Japanese Patent Application Laid-Open No. 8-255331, the amount of change in the flying height increases as the seek speed increases, so that there is a possibility that abrasion may occur due to contact between the slider and the disk. The problem arises.

Further, as the disk speed increases, a problem arises in that the flying height change between the inner and outer circumferences of the disk increases.

Further, when the flying height is minimized, the area in contact with the disk increases. JP-A-8-255331
In the taper processing as disclosed in Japanese Patent Application Laid-Open Publication No. H11-264, a taper processing step is required at the time of manufacturing the HDD, and there is a problem that the processing is complicated.

An object of the present invention is to provide a slider having an air bearing surface with a small flying height variation even when the flying height is minimized and the change speed (seek speed) of the skew angle is increased. It is in.

It is another object of the present invention to provide a slider design method and slider optimized to minimize the change in flying height from an inner diameter (ID) track to an outer diameter (OD) track. It is in.

Still another object of the present invention is to provide a slider capable of forming a shape having a different wall angle at a recess boundary with a simple configuration.

It is still another object of the present invention to provide a slider that produces different pressures at different skew angles at different portions of the air bearing surface, thereby minimizing flying height variations due to disk speed and skew angle. It is in.

Still another object of the present invention is to prevent the slider from stopping when the disk is stopped and the slider to fly at a lower disk speed at the start of the disk and during the disk stop operation, thereby suppressing the contact between the disk and the slider. It is to provide a slider which can be used.

[0031]

SUMMARY OF THE INVENTION A slider of a disk recording / reproducing apparatus according to the present invention has an inflow end and an outflow end located upstream and downstream of an air flow generated between the disk and a recording medium. A slider of a disk recording / reproducing apparatus having a floating surface facing a medium, wherein a first pad formed on the inflow end side of the floating surface and a second pad formed on the inflow end side of the floating surface. And a third pad formed on the outflow end side of the air bearing surface, wherein at least one of the first pad, the second pad, and the third pad is It has a first ridgeline formed on the inflow end side, and the first ridgeline includes a curve having a convex portion on the inflow end side, thereby achieving the above object.

The slider has a first recess formed to have a depth in a direction opposite to the recording medium with respect to the first pad, and the recording medium has a depth with respect to the second pad. A second formed to have a depth in the opposite direction
A third recess formed to have a depth in a direction opposite to the recording medium with respect to the third pad, and a direction opposite to the recording medium with respect to the first recess. A fourth recess formed so as to have a depth in the second recess, wherein the fourth recess includes the first recess and the second recess.
And the third pad is formed deeper than any of the third recess and the third recess, and the first pad is located in the first recess,
The second pad may be located at the second recess, and the third pad may be located at the third recess.

[0033] The first ridge may include an arc.

[0034] The first ridge may include an ellipse.

The first pad is formed on the inner peripheral side of the recording medium, the second pad is formed on the outer peripheral side of the recording medium, and at least one of the first pad and the second pad is , Formed at the boundary with the fourth recess, at least one of the first pad and the second pad has a height between a step formed on the inner peripheral side and a step formed on the outer peripheral side. May be different.

[0036] The first ridge includes a second ridge formed on the inflow end side of the third pad, and the second ridge is a third ridge formed at a boundary with the fourth recess. Wherein the third pad has a first step formed on the outer peripheral side of the recording medium and a second step formed on the inner peripheral side of the recording medium, wherein the first step is: It may be higher than the second step.

When the width of the first pad is b, the width of the second pad is c, and the ratio of the widths of both pads is a = b / c, b ≠ c, and the recording medium The ratio a of the two pad widths may be such that the variation in the flying height of the slider from the inner circumference to the outer circumference is minimized.

[0038] The third pad may be arranged so that a fluctuation of a floating amount of the slider is minimized.

[0039] The slider may have a center axis in a direction along the direction of air flow, and a center of the third pad may be arranged at a position different from the center axis.

The direction substantially perpendicular to the direction of the air flow of the slider is defined as a slider width direction, the width of the slider is L2, and the distance from the center of the third pad to the end in the width direction of the slider is L1. In this case, the third pad may be arranged such that the width ratio of the position of the third pad defined by L = L1 / L2 is a ratio that minimizes the fluctuation of the flying height. .

[0041] The slider may have a central axis in a direction along the direction of air flow, and the slider may include a recording element provided on the central axis.

At least one of the first pad, the second pad and the third pad is formed on a first step formed on an outer peripheral side of the recording medium and formed on an inner peripheral side of the recording medium. A first step of the first step
The wall angle and the second wall angle of the second step may be different.

[0043] The first wall angle may be smaller than the second wall angle.

At least one of the first pad, the second pad, and the third pad is formed on a first step formed on an outer peripheral side of the recording medium and formed on an inner peripheral side of the recording medium. A first step of the first step
The depth and the second depth of the second step may be different.

[0045] The first step may be larger than the second step.

According to one aspect of the present invention, the ridge on the inflow end side of the pad provided in the recess provided on the flying surface of the slider is non-linear. As a result, even if the skew angle changes, the pressure generated below the pad can be appropriately adjusted, and not only the fluctuation of the flying height can be suppressed, but also the accumulation of dust and the like at the front edge of the pad can be prevented, and the recording / reproduction by the head This has the effect of stabilizing the characteristics.

According to another aspect of the present invention, the boundary between at least one outer peripheral ridge line of the two pads at the inflow end and the fourth recess is made coincident, and the height of the step is different.
As a result, the flying height on the outer peripheral side of the disk can be suppressed, and there is an effect that fluctuation in the flying height of the slider can be suppressed.

According to still another aspect of the present invention, a part of the ridge on the inflow end side of the outflow end pad is a boundary with the fourth recess, and the height of the step on the inflow end side of the third pad is high. Are different in the width direction of the pad. As a result, the flying height on the outer peripheral side of the disk can be suppressed, and there is an effect that fluctuation in the flying height of the slider can be suppressed.

According to still another aspect of the present invention, the width of the first pad is b, the width of the second pad is c, and the ratio of the widths of both pads is a = b / Assuming that c, b ≠ C, and a ratio a between the two pad widths that minimizes the fluctuation of the flying height from the inner circumference to the outer circumference of the recording medium. As a result, there is an effect that a slider capable of reducing the variation of the flying height due to the skew angle can be realized by the pad width ratio a.

According to still another aspect of the present invention, the magnetic recording element is provided at the center of the outflow end, and the center of the third pad at the outflow end is shifted from the center of the outflow end. This has the effect of realizing a slider that can reduce the variation in flying height due to the skew angle by a simple method of changing the center position of the third pad.

According to still another aspect of the present invention, the recording element is provided on the center axis of the slider along the direction of air flow, the direction perpendicular to the direction of air flow of the slider is defined as the slider width direction, and the slider width L2 When the distance from the center of the third pad to the end in the width direction of the slider is L1, L = L1
The width ratio of the position of the third pad defined by / L2 is a ratio that minimizes the variation in flying height. As a result, the flying height on the outer peripheral side of the disk can be suppressed, and there is an effect that fluctuation in the flying height of the slider can be suppressed.

According to still another aspect of the present invention, a first pad and a second pad provided on the flying surface of the slider and provided on the inflow end side, and a third pad provided on the outflow end side. And at least one pad has a wall angle of a step on the inflow end side different in a direction perpendicular to the flow direction. This has the effect of realizing a slider that can reduce the amount of fluctuation of the flying height due to the skew angle by a simple method in which the wall angle of the step on the inflow end side of the pad differs in the direction perpendicular to the flow direction. Further, when the skew angle is small, the slider flies at a lower speed from the disk and the wear of the slider and the disk can be suppressed.

According to still another aspect of the present invention, an air bearing surface having an inflow end and an outflow end located upstream and downstream of an air flow generated between the air and a recording medium and facing the recording medium is provided. At least one pad comprising: a slider having a first pad, a second pad provided on an inflow end side, and a third pad provided on an outflow end side provided on a flying surface of the slider. The depth of the step on the inflow end side of the pad is different in the direction perpendicular to the flow direction, and thus the depth of the step on the inflow end side of the pad is different in the direction perpendicular to the flow direction. This has the effect of realizing a slider capable of reducing the amount of fluctuation of the flying height.

According to still another aspect of the present invention, there is an effect that when the skew angle is small, the slider flies at a lower speed from the disk and wear of the slider and the disk can be suppressed.

[0055]

Embodiments of the present invention will be described below.

(Embodiment 1) FIG. 1 is a perspective view of the inside of an HDD 100. FIG. 2 is a sectional view of the HDD 100.

Referring to FIGS. 1 and 2, the HDD is covered with a housing cover (not shown). A suspension 14 is attached to a plurality of distal ends 5A of the actuator arm 5 rotatably attached to the actuator shaft 20. At the tip of each suspension 14, a slider 3 that carries a magnetic transducer or a read / write head 99 (FIG. 4) is attached.

The main shaft 1 is mounted in the housing 7. A large number of disks 2 are rotatably mounted on the main shaft 1 at intervals. Disk 2 is a motor 8
The main shaft 1 rotates in the direction indicated by the arrow A together with the main shaft 1. Information is written onto the disk 2 by the head 99 (FIG. 4) located in the slider 3 and positioned by the actuator arm set 5 or the disk 2
Read from.

The sliders 3 are provided on both the front and back surfaces of the disks 2, and information is written on or read from the front and back surfaces of each disk 2. Power is supplied to the actuator arm 5 by the voice coil motor 6, and the actuator arm 5 swings around the actuator shaft 20.

The slider 3 and its integrated magnetic transducer (not shown) move over the surface of the disk 2 so that a magnetic representation of the data can be stored on any track on the disk 2. In the HDD, the movement of this transducer is due to rotation about the actuator axis 20. By rotating the actuator / actuator arm 5, the slider 3 and the transducer therein can be positioned on any track on the surface of the disk 2.

FIG. 3 is a detailed view of one of the disks 2 as viewed from above. As is well known in the HDD technology, each disk 2 has a row of concentric tracks on which magnetic information is recorded. The inner diameter (ID) track 11 is the innermost concentric track where data is stored. Outer diameter (OD) track 10 is the outermost concentric track on which data is stored.

FIG. 4 shows the shape of the air bearing surface (ABS) of the slider 3. The ABS is fixed to the lower surface of the slider 3 and faces the disk surface. ABS
May be formed by molding, etching, laser cutting, ion pulverizing, general-purpose machining, or various other methods.

The slider 3 has an inflow end 21 and an outflow end 2
2. An inner peripheral end 23 and an outer peripheral end 24 are formed. As shown in FIG. 4, an inner pad 31, an outer pad 32, and an outflow end pad 33 are formed on the slider 3. Also,
An inflow end recess 41 and an outflow end recess 42 each having a lower height are formed from each pad, and a central recess 4 having a lower height is formed.
3 is formed.

An inner pad 31 and an outer pad 32 are formed in the inflow end recess 41, and a lower inflow end recess 41 is located on the inflow end 21 side of the inner pad 31 and the outer pad 32. The inflow end 21 faces the direction in which the disk surface rotates (the direction of the arrow R1). Rotating disk 2
Due to the viscous effect of the air, the air passes under the inflow end recess 41 and is pushed down below the inner pad 31 and the outer pad 32.

For this reason, a pressure is generated in the direction of the disk 2 against the slider 3 below each of the inner pad 31 and the outer pad 32. As a result, an air lubrication film is formed. The pressure acting on the slider 3 in the direction of the disk 2 is called positive pressure, and the pressure acting on the disk 2 in the direction of the slider 3 is called negative pressure.

The central recess 43 is formed to have a sufficient depth so that lift is not generated by the air lubrication film effect. The recording transducer or read / write head 99 is usually located at the rear end of the outflow end pad 33.

The inflow end recess 41 is formed to have a predetermined depth so as to generate a slight lift. In the present embodiment, the inflow end recess 41 and the outflow end recess 42
Has a depth of 0.2 μm and the central recess 43 has a depth of 1 μm.
m.

The inner pad 31 at the inflow end which is the first pad
And the outer pad 32 as a second pad are formed at an inner peripheral end 23 located inside the inflow end and an inner peripheral end 24 located outside the outer pad, respectively. The inflow side ridgelines 71 and 72 of both the inner pad 31 and the outer pad 32 have an arc shape. An outflow end pad 33 as a third pad is formed on the outflow end 22 side. Outflow end pad 33
The ridge line 73 on the inflow end side has an arc shape.

FIG. 4 also shows the vertical axis 60. The angle of the airflow with respect to the vertical axis 60 of the slider 3 is called a skew angle. The skew angle is the rotation actuator axis 2
0 depends on the mounting position of the actuator arm 5. Skew angle is from ID track 11 to OD track 1
It changes greatly up to zero. Also, the skew angle can be either positive or negative. If the actuator arm 5 is positioned such that the airflow hits the outer peripheral end 24 of the slider 3 from the direction indicated by the arrow E, the skew angle is positive. The air flow is changed from the direction indicated by the arrow F to the slider 3.
Actuator arm 5 so as to hit the inner peripheral end 23 of the
Is located, the skew angle is said to be negative.
The direction of the airflow in each case is indicated by arrows E and F. An air flow having a positive skew angle is indicated by an arrow E, and an air flow having a negative skew angle is indicated by an arrow F.

In the first embodiment, the rotary actuator / actuator arm 5 is
Are set so that the skew becomes a positive maximum angle and the OD track 10 becomes a negative minimum angle. Due to the rotation of the actuator arm 5, the inflow direction of the airflow is different, and all the pads (the inner pads 3)
1. The inflow speed is not constant under the outer pad 32 and the outflow end pad 33).

In the first embodiment, the rotation speed of the disk 2 is constant. For this reason, due to the fluctuation of the disk radius between the ID track 11 and the OD track 10,
The disk speed below the slider 3 is different, and the air velocity is different. The ID track 11 has the lowest speed, and the OD track 10 has the highest speed.

Disk 2 of swing actuator HDD
When the slider 3 floats from the ID track 11 to the OD track 10 on the surface of the
The shape of the pressure distribution of the air lubricating film is determined by the shape of the outflow end pad 33. Slider is ID track 1
5 shows the shape of the pressure distribution of the air lubricating film when it is positioned on
Shown in As is clear from FIG. 5, a positive pressure is generated below the slider 3 by the air lubrication film in the inner pad 31, the outer pad 32, and the outflow end pad 33. Further, a negative pressure is generated at the ridge lines 81, 82, 83, 84 and 85 of the inflow end recess 41.

The slider 3 has an inner pad 31, an outer pad 3
2, the positive and negative pressures of the air lubricating film, the negative pressure of the air lubricating film, and the pressing force of the suspension 14 generated at the outflow end recess 41, the outflow end recess 42, the center recess 43, and the like. It is floated and held by a predetermined amount from 2.

The shape of each pad is designed to produce a floating altitude with respect to the skew angle and a pressure distribution such that the fluctuation of the floating altitude is minimized. The pressure generated at the inner pad 31, the outer pad 32, and the outflow end pad 33 is a floating force that causes the slider 3 to fly. The degree of generation of the pressure is determined by the shapes and positions of the inner pad 31, the outer pad 32, and the outflow end pad 33.

The inflow side ridge lines 71 and 72 on the inner circumference side of the inner pad 31 and the outer pad 32 at the inflow end of this embodiment are arcs. Since the inner pad 31 and the outer pad 32 are formed in an arc shape in this manner, the flow distance of the air below the inner pad 31 and the outer pad 32 varies depending on the skew angle, so that the generated pressure can be adjusted. .

When the skew angle is 0 degrees or negative, the distance from the ridge line to the center of the arc in the air flow direction at each of the pads 31 and 32 is constant regardless of the skew angle. The distance from the ridge line to the center of the arc is the distance that air flows under each of the pads 31 and 32. Since the distance from the ridge line to the center of the circular arc is constant regardless of the skew angle, it is possible to suppress the occurrence of pressure fluctuation due to the change in the skew angle. By adjusting the radius of each pad 31, 32, the pressure generated at both pads 31, 32 can be adjusted. By adjusting the center position of the arc of each pad 31, 32, both pads 31, 32 can also be adjusted.
The pressure generated in can be adjusted.

The inflow side ridge 71 on the inner peripheral side of the inner pad 31 is a boundary with the shallow first recess 41, and the ridge 82 on the center axis 60 side of the inner pad 31 is formed with the deep center recess 4.
3 is the boundary. Also, the inner peripheral side ridge line 7 of the outer pad 32 is formed.
Reference numeral 2 denotes an arc and a boundary with the shallow first recess 41, and the outer peripheral side ridge line coincides with the boundary with the outer ridge line 24. The wall angles of the steps at these ridges depend on the depth of the recess, and are near vertical (0 degrees) at the boundary with the deep central recess 43 and at the boundary with the shallow first recess 41 at the central recess 43. It is gently larger than the wall angle at the border.

Therefore, in the ridge lines 71 and 72 on the inner peripheral side of the inner pad 31 and the outer pad 32, the step wall angle is large and gentle, and the step wall angle of the ridge lines 82 and 24 on the outer peripheral side is small (close to vertical). ). Therefore, the high-speed air flow E collides with the wall surface from the outer peripheral side, and the inner pad 31
And it is difficult to flow below the outer pad 32. As a result, there is an effect that the pressure generated in the inner pad 31 and the outer pad 32 is suppressed. On the other hand, the air flow F flowing from the inner circumference side
Are the inner pad 31 and the outer pad 3 because the step wall angle is large.
2, the inner pad 31 and the outer pad 32 are likely to generate a positive pressure.

The positions of the inner pad 31 and the outer pad 32 are
Since there is a difference in radius with respect to the center of rotation of the disk 2, the velocity of air between the inner pad 31 and the outer pad 32 is different. Assuming that the width of the first pad is b, the width of the second pad is c, and this ratio is a, the relationship between the radius and the flying height when the width ratio a is variously changed is shown in FIG. Show. The horizontal axis is the radius, and the vertical axis is the flying height. The smaller radius is the inner circumference, and the larger radius is the outer circumference.

As apparent from FIG. 6, the flying height depends on a, and when a = 1.54, the difference in the flying height from the inner circumference to the outer circumference (flying height variation) is the smallest, and a = 1. 25, the flying height fluctuation is large.

FIG. 7 shows the relationship between the width ratio a and the flying height variation. The variation in the flying height varies depending on the ratio of the width of the first pad to the width of the second pad. As is apparent from FIG.
At 1.54, the flying height variation is minimized. In this manner, the width of the inner pad 31 and the width of the outer pad 32 are different, and as shown in FIG. The difference in floating force generated in the outer pad 32 can be suppressed. Therefore, flying fluctuation of the slider 3 can be minimized.

The semicircular outflow end pad 33 is connected to the outflow end 2.
It is formed on two sides. The outflow end pad 33 is formed on a semicircular outflow end recess 42 one step lower than the outflow end pad 33. Outflow end recess 4 depending on the direction of air flow
The center of the outflow end pad 33 and the center of the outflow end recess 42 do not coincide with each other and are shifted so that the distance that air flows under the space 2 changes. In addition, the ridge 7 on the inflow side of the outflow end pad 33.
3 is formed such that the outer peripheral side portion 73A coincides with the ridge line 76 of the outflow end recess 42.

The operation of the slider 3 when the skew angle changes in this configuration will be described. When the skew angle is negative (when air flows in from the arrow F), the air flow distance below the outflow end recess 42 is long. As the skew angle increases, the distance of air flow below the outflow end recess 42 sandwiched between the ridgelines 76 and 73 decreases. Therefore, the larger the skew angle, the shorter the air flow distance, and the lower the pressure generated below the outflow end recess 42.

Further, the outer peripheral side of the ridge line 73 on the inflow end side of the outflow end pad 33 forms a boundary with the deep center recess 43, and the inner peripheral side forms a boundary with the shallow outflow end recess 42.

Outflow end pad 3 in section AA in FIG.
FIG. 8 is an enlarged cross-sectional view of a main part near 3. Outflow end pad 3
On the inner circumference 23 side of 3, an outflow end recess 42 and a shallow wall surface 33A are formed. On the outer peripheral side, a wall surface 33B with the deep center recess 43 is formed. The outflow end pad 33 is formed such that the wall angle θA is large and gentle on the inner peripheral wall surface 33A, and is small and steep on the outer peripheral wall surface 33B.

Since the step H1 is high on the outer peripheral side of the outflow end pad 33 and the step H2 is low on the inner peripheral side, when the skew angle is large, that is, when air flows from the outer peripheral side, the air to the outflow end pad 33 Inflow is reduced. When the skew angle is small, the step H2 is shallow, so that the air flows into the outflow end pad 33 more frequently. As described above, a part of the ridge 73 on the air inflow side of the outflow end pad 33 (the outer peripheral side portion 73)
By making A) coincide with the boundary 76 of the deep center recess 43, a positive pressure is less likely to be generated as the skew angle increases, that is, when air flows in from the outer peripheral side. Conversely, a positive pressure tends to be generated with respect to the inflow of air from the inner peripheral side.

The wall angle of the wall surface 33B between the outflow end pad 33 and the deep center recess 43 is nearly vertical (0 degrees).
The wall angle of the wall surface 33A between the outflow end pad 33 and the shallow outflow end recess 42 is formed smoothly.

When the skew angle is large, since the wall angle of the wall surface 33B is small (close to 0 degree), the air collides with the wall surface 33B and it becomes difficult for air to flow below the outflow end pad 33. Therefore, generation of pressure below the outflow end pad 33 is suppressed. Further, when the skew angle is small, the air easily flows below the outflow end pad 33 and the pressure is easily generated because the wall angle of the wall surface 33A is large.

When the skew angle is small,
Since the wall angle of A is large, air easily flows out of the outflow end pad 33.
Pressure tends to be generated below. When the skew angle is small, that is, when the disk stops on the ID track 11 side, the slider 3 stops on the disk 2 and the slider 3 floats by the disk start and disk stop operation. It flows below the outflow end pad 33. When the skew angle is small, the wall angle of the wall surface 33A in the air inflow direction is large, so that air can flow more easily below the outflow end pad 33, and the pressure generated below the outflow end pad 33 is such that the disk speed is lower. It becomes high with. Therefore, the slider 3 flies at a lower disk speed. Since the slider flies at a lower speed, contact between the disk 2 and the slider 3 can be suppressed, and wear of the slider and the disk can be reduced.

In the inner pad 31 and the outer pad 32,
Since the wall angle is set large when the skew angle is small, the same effect can be obtained.

In the present embodiment, an asymmetric shape is adopted with respect to the center axis 60 of the slider 3 in the air flow direction. The recording element 99 is provided at the outflow end of the central shaft 60. The difference in the flying height between the inner peripheral side and the outer peripheral side of the slider 3 is adjusted according to the position of the pad. If the pad is on the outer peripheral side, the floating amount on the outer peripheral side increases, and if the pad is on the inner peripheral side, the floating amount on the inner peripheral side increases.

FIG. 9 shows the result of a simulation in which the distance from the inner peripheral side of the outflow end pad 33 is variously changed. Depending on the position of the outflow end pad 33, the ID track 11 and the OD
The flying height variation on the track 10 is different.

FIG. 10 shows the relationship between the fluctuation of the flying height and the position of the outflow end pad 33. Let the width of the slider be l2 and the distance l1 from the inner peripheral end of the center of the outflow end pad 33, l1
And the ratio of l2 to L. As is apparent from FIG. 9, the variation in the flying height varies depending on the position of the outflow end pad 33, and there is a width ratio L that minimizes the variation in the flying height.

FIG. 10 shows the relationship between the position of the outflow end pad 33 and the fluctuation of the flying height. In the present embodiment, the width ratio L = 0.5
In the state of No. 4, the fluctuation of the flying height is smallest. By providing the outflow end pad 33 at the position where the width ratio L at which the flying height variation is minimized, the flying height variation of the slider 3 can be minimized.

(Embodiment 2) The present invention relates to Embodiment 1
However, the present invention is not limited to the ABS shape described above, and some problems can be overcome by the slider 103 shown in FIG.

In FIG. 11, the inflow end ridge line of the pad is not an arc but an arbitrary curve. Even in such a configuration, the skew angle can be obtained by setting the width ratio b1 / c1 between the width b1 of the first pad 131 and the width c1 of the second pad 132 so as to minimize the flying height variation. It is possible to provide a slider which is less affected by the above.

[0097]

As described above, according to the present invention, even when the slider flying height is small and the seek speed is high, there is an excellent effect that the variation in the flying height is small.

Further, according to the present invention, there is an excellent effect that wear due to contact between the slider and the disk can be suppressed.

Further, according to the present invention, it is possible to provide a slider design method and a slider which are optimized so as to minimize a change in flying height from an inner diameter (ID) track to an outer diameter (OD) track. It has the effect.

Further, according to the present invention, there is provided an excellent effect that different portions of the air bearing surface have different pressures at different skew angles, and fluctuations in the flying height due to the rotational speed of the disk and the skew angle can be minimized. Play.

Further, according to the present invention, the slider stops when the disk stops, and the slider flies at a lower disk speed at the start of the disk and during the disk stop operation.
An excellent effect that the contact between the disk and the slider can be suppressed is achieved.

Further, according to the present invention, an excellent effect that a taper machining step of the slider is not required can be obtained, and a slider can be provided which can machine a wall angle at a recess boundary with general machining accuracy.

[Brief description of the drawings]

FIG. 1 is a perspective view of an HDD according to a first embodiment.

FIG. 2 is a sectional view of the HDD according to the first embodiment;

FIG. 3 is a detailed view of one of the disks 2 of the first embodiment as viewed from above.

FIG. 4 is a diagram illustrating the shape of an air bearing surface (ABS) of the slider 3 according to the first embodiment.

FIG. 5 is a diagram showing the shape of the pressure distribution of the air lubrication film when the slider of the first embodiment is an ID.

FIG. 6 is a graph showing the relationship between the width ratio of the first and second pads and the flying height according to the first embodiment;

FIG. 7 is a graph showing the relationship between the width ratio of the first and second pads and the flying height variation in the first embodiment.

FIG. 8 is an enlarged cross-sectional view of a main part near the outflow end pad 33 according to the first embodiment.

FIG. 9 is a graph showing the relationship between the width ratio of the outflow end pad position and the flying height according to the first embodiment.

FIG. 10 is a graph showing the relationship between the width ratio of the outflow end pad position and the flying height variation according to the first embodiment.

FIG. 11 is a diagram illustrating a shape of an air bearing surface (ABS) of a slider 3 according to the second embodiment.

[Explanation of symbols]

 Reference Signs List 1 spindle 2 disc 3 slider 5 actuator arm 6 voice coil motor 7 housing 8 motor 10 outer diameter (OD) track 11 inner diameter (ID) track 14 suspension 20 actuator shaft 21 inflow end 22 outflow end 23 inner circumference end 24 outer circumference Side end 31 Inner pad 32 Outer pad 33 Outflow end pad 41 Inflow end recess 42 Outflow end recess 43 Center recess 99 Head

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kaoru Matsuoka 1006 Kazuma Kadoma, Kadoma-shi, Osaka Matsushita Electric Industrial Co., Ltd. F-term (reference) 5D042 NA02 PA01 PA05 PA05 QA02 QA03

Claims (15)

[Claims] 1. A slider of a disk recording / reproducing apparatus having an inflow end and an outflow end located upstream and downstream of an air flow generated between the recording medium and a floating surface facing the recording medium. A first pad formed on the inflow end side of the floating surface; a second pad formed on the inflow end side of the floating surface; and a second pad formed on the outflow end side of the floating surface. A third pad, and at least one of the first pad, the second pad, and the third pad has a first ridge line formed on the inflow end side; A slider of a disk recording / reproducing apparatus, wherein one ridge includes a curve having a convex portion on the inflow end side. A first recess formed in the slider so as to have a depth in a direction opposite to that of the recording medium with respect to the first pad; and a recording device in which the recording is performed with respect to the second pad. A second recess formed to have a depth in a direction opposite to the medium; and a third recess formed to have a depth in a direction opposite to the recording medium with respect to the third pad. And a fourth recess formed to have a depth in a direction opposite to the recording medium with respect to the first recess, wherein the fourth recess includes the first recess and the fourth recess. The first pad is located in the first recess, the second pad is located in the second recess, and the second pad is located in the second recess. The disk of claim 1, wherein a third pad is located in the third recess. The slider of the recording and reproducing apparatus. 3. The method according to claim 1, wherein the first ridge includes an arc.
Disc recording / reproducing device slider 4. The method according to claim 1, wherein the first ridge includes an ellipse.
Disc recording / reproducing device slider 5. The first pad is formed on an inner peripheral side of the recording medium, the second pad is formed on an outer peripheral side of the recording medium, and at least one of a first pad and a second pad is formed. One is formed at the boundary with the fourth recess, and at least one of the first pad and the second pad has a height difference between a step formed on the inner peripheral side and a step formed on the outer peripheral side. 3. The slider of the disk recording / reproducing apparatus according to claim 2, wherein the slider has different values. 6. The first ridge line includes a second ridge line formed on the inflow end side of the third pad, wherein the second ridge line is formed at a boundary with the fourth recess. A third step formed on an outer peripheral side of the recording medium, and a second step formed on an inner peripheral side of the recording medium.
The slider according to claim 2, wherein the slider has a step, and wherein the first step is higher than the second step. 7. When the width of the first pad is b, the width of the second pad is c, and the ratio of both pad widths is a = b / c, b ≠ c. 2. The slider according to claim 1, wherein the ratio a of the two pad widths is such that the flying height variation of the slider from the inner circumference to the outer circumference of the recording medium is minimized. 8. The slider according to claim 1, wherein the third pad is arranged so that a change in a floating amount of the slider is minimized. 9. The disk according to claim 8, wherein the slider has a center axis in a direction along an air flow direction, and a center of the third pad is arranged at a position different from the center axis. A slider for a recording / reproducing device. 10. A slider width direction is defined as a direction substantially orthogonal to a direction of airflow of the slider, and the width of the slider is L2, and a distance from a center of the third pad to an end of the slider in the width direction. Is defined as L1, so that the width ratio of the position of the third pad defined by L = L1 / L2 is a ratio that minimizes the fluctuation of the flying height.
9. The slider according to claim 8, wherein the third pad is arranged. 11. The disk recording / reproducing apparatus according to claim 8, wherein the slider has a center axis in a direction along an air flow direction, and the slider includes a recording element provided on the center axis. Slider. 12. At least one of the first pad, the second pad, and the third pad includes a first step formed on an outer peripheral side of the recording medium and an inner peripheral side of the recording medium. The slider of the disk recording / reproducing apparatus according to claim 1, further comprising a second step formed in the first step, wherein a first wall angle of the first step and a second wall angle of the second step are different. 13. The slider according to claim 12, wherein the first wall angle is smaller than the second wall angle. 14. At least one of the first pad, the second pad, and the third pad is a first step formed on an outer peripheral side of the recording medium and an inner peripheral side of the recording medium. The slider of the disk recording / reproducing apparatus according to claim 1, further comprising: a second step formed in the first step, wherein a first depth of the first step and a second depth of the second step are different. 15. The slider according to claim 14, wherein the first step is larger than the second step.