JP3724629B2 - Head slider - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a head slider used in a disk device or the like, and more particularly to a negative pressure utilizing head slider that utilizes negative pressure.
[0002]
[Prior art]
The magnetic disk device includes a magnetic head that records and reproduces data on both sides of a magnetic disk medium. In a magnetic disk apparatus, a magnetic head is mounted on a support made of a ceramic material called a slider, and is supported in a state of floating with a predetermined interval from a data recording surface of a magnetic disk medium.
[0003]
The magnetic disk device includes one or several magnetic disk media. These magnetic disk media are stacked on the main shaft at intervals so as not to contact each other.
[0004]
The surface of each magnetic disk medium is apparently the same. In practice, however, each surface is divided into sections called tracks where data is stored. These trucks are arranged as concentric circles like tree rings. The track of the magnetic disk drive is essentially a replacement of a 45-turn record groove. Each track in the magnetic disk drive is further divided into sectors, which are just sections in one concentric track.
[0005]
Magnetic disk media are made of various materials such as metal, resin, and glass. In a magnetic disk medium, data is stored and retrieved by an electromagnet generally known as a transformer.
[0006]
In order to store data on a magnetic disk medium, the surface of the magnetic disk medium is magnetized using a small ceramic block called a head slider. The head slider incorporates a magnetic transducer that is a so-called write magnetic head. More particularly, the head slider incorporating the write magnetic head floats at a height of several hundred to several tens of nanometers from the surface of the magnetic disk medium, and the magnetic head is excited in several states, Is magnetized so as to correspond to the data.
[0007]
In order to retrieve data stored on the magnetic disk medium, a head slider containing a read magnetic head is floated on the magnetic disk medium. At this time, a current is induced in the read magnetic head by the magnetized portion on the track. By analyzing the current output from the read magnetic head, the computer system can reproduce and use the data stored on the magnetic disk medium.
[0008]
Some magnetic disk devices use separate read and write magnetic heads, but most current magnetic disk devices use magnetic heads that perform both read and write operations. Recently, magnetoresistive elements and inductance elements have been used as read magnetic heads.
[0009]
Similar to records, both sides of a magnetic disk medium are typically used to store data or information necessary for the operation of other magnetic disk devices. Since the magnetic disk media are stacked and spaced from each other, each of the stacked magnetic disk media has a unique read / write magnetic head on both the front and back surfaces. This is as if a stereo device with record needles on both sides could play both sides of the record at the same time.
[0010]
There are two types of magnetic disk devices: a magnetic disk device having a rotary actuator and a magnetic disk device having a linear actuator. A rotary actuator has an actuator arm similar to the tone arm of a record player. Like the tone arm, its actuator arm rotates so that a head slider with a built-in read / write magnetic head can be moved to a position above various tracks on the magnetic disk medium. In this way, the read / write magnetic head can be used to magnetize the track on the surface of the magnetic disk medium in a pattern corresponding to data, or to detect the magnetized pattern on the track. For example, if the required data is stored on two different tracks of a magnetic disk medium, the actuator arm can move from one track to the other to read what is representative of the data. Rotate to the next track. The present invention relates to a rotary actuator / magnetic disk device.
[0011]
Linear actuators also have similar actuator arms, but the movement of position is done by linear movement rather than rotation.
[0012]
Today's magnetic disk drives are very different from large-diameter magnetic disk drives using linear actuators. Current magnetic disks are very small and data access is fast. Currently, magnetic disk drives are equipped with rotary actuators to process 5.25 ", 3.50", 2.50 ", 1.80" diameter disks and to obtain fast access speeds. .
[0013]
By mainly using a rotary actuator, the sliding between the head slider and the magnetic disk medium and the air flow under the head slider are no longer essentially unidirectional, with various angles with respect to the longitudinal axis of the head slider. Has spread.
[0014]
In addition, the high-speed search operation of the actuator being accessed causes the sliding direction between the head slider and the magnetic disk medium and the direction of the air flow flowing under the head slider to be inclined with respect to the vertical axis.
[0015]
Therefore, in recent rotary actuators and magnetic disk devices, the sliding direction is no longer considered to be a vertical axis direction from the front to the rear of the head slider or slightly deviate therefrom.
[0016]
The angle of the sliding direction of the magnetic disk medium with respect to the longitudinal axis of the head slider is called a skew angle. The skew angle is positive when the actuator arm is positioned so that the sliding direction is at or outside the head slider. The skew angle is negative when the actuator arm is positioned to hit the inner edge or hub of the slider.
[0017]
A head slider is attached to the tip of an actuator arm of a magnetic disk device, and a read / write magnetic head is incorporated therein. The head slider is formed with a pressure generating surface. An air flow generated with the rotation of the magnetic disk medium is drawn between the pressure generating surface and the surface of the magnetic disk medium, whereby the head slider floats from the magnetic disk medium.
[0018]
Thus, the head slider floats on the rotating magnetic disk medium as described above. The flying height is the thickness of the air lubricating film, that is, the distance between the surface of the magnetic disk medium and the head slider.
[0019]
Thus, the surface of the head slider facing the magnetic disk medium forms an air lubrication surface having a pressure generating surface, and forms a self-pressurizing air lubrication film between the head slider and the magnetic disk medium storage surface. Is maintained. The air lubrication film makes it difficult for the head slider and the magnetic disk medium to come into mechanical contact during rotation of the magnetic disk medium, thereby suppressing friction and wear.
[0020]
In order for the head slider to form a non-contact state with the magnetic disk medium, the edge on the air inflow end side of the pressure generating surface is tapered to promote the inflow of airflow.
[0021]
Since the formation of this taper is usually performed by machining, variations in taper processing, for example, variations in the length or angle of the taper portion, greatly affect the flying characteristics of the head slider. In conventional head sliders, high-precision work is required for taper processing, which hinders cost reduction.
[0022]
Japanese Patent Application Laid-Open No. 8-255331 discloses a head slider in which variation in taper processing does not greatly affect the flying characteristics. According to Japanese Patent Laid-Open No. 8-255331, the end of the taper formed on the air inflow end side of the pressure generating surface is at a position where the width of the pressure generating surface decreases from the air inflow end toward the air outflow end. By doing so, it is described that the variation in the length of the taper can make it difficult to affect the flying characteristics.
[0023]
Japanese Patent Application Laid-Open No. 10-255425 discloses a second height generating surface that is smaller than the first height generating surface on the air inflow end side of the first height generating surface. By arranging them adjacent to each other, it is possible to promote the inflow of air into the pressure generating surface without forming a taper by machining, and it is not necessary to form a taper by machining that requires highly accurate work. It is described.
[0024]
[Problems to be solved by the invention]
Since the head slider floats from the magnetic disk medium due to the air flow generated as the magnetic disk medium rotates, the head slider cannot float from the magnetic disk medium when the magnetic disk medium is stopped rotating.
[0025]
Therefore, many magnetic disk apparatuses employ a start / stop system called a CSS (contact start / stop) system. In the CSS system, when the magnetic disk medium is stopped rotating, the head slider that has been in contact with the surface of the magnetic disk medium gradually floats as the rotational speed of the magnetic disk medium increases. When a certain rotational speed at which recording / reproduction is performed with respect to the magnetic head, for example, a rotational speed of 7200 rpm, is reached, the head slider floats completely from the surface of the magnetic disk medium.
[0026]
Further, the CSS method is performed in an area called a CSS zone disposed in the inner periphery of the magnetic disk medium, and a protrusion called a periodic bump having a height of 10 nm, for example, is formed in the CSS zone. The magnetic disk medium is prevented from being attracted.
[0027]
In a magnetic disk device adopting the CSS system, sliding contact is repeated between the magnetic disk medium and the pressure generating surface of the head slider in an area where the rotation speed of the magnetic disk medium is relatively small when starting or stopping. Therefore, wear of the pressure generation surface of the head slider is inevitable.
[0028]
Under the CSS method, the edge portion of the pressure generating surface facing the disk sliding direction collides violently with the bump formed on the magnetic disk medium surface, so the edge portion located on the air inflow end side The amount of wear is large compared to other parts of the pressure generating surface.
[0029]
When the edge portion located on the air inflow end side is worn, a taper action appears, and the flying characteristics of the head slider change greatly, making it difficult to ensure the reliability of the magnetic disk device.
[0030]
Further, in recent magnetic disk devices, there is a problem that the flying height of the head slider varies greatly between the inner and outer peripheral portions of the magnetic disk medium due to the increased rotational speed of the magnetic disk medium.
The present invention has been devised in view of the above disadvantages, and provides a head slider that suppresses wear of the edge of the pressure generating surface by the CSS method and minimizes the temporal change of the flying characteristics of the head slider. It is aimed.
[0031]
Another object of the present invention is to provide a head slider that minimizes the flying height variation of the head slider at the inner and outer peripheral portions of the magnetic disk medium.
[0032]
[Means for Solving the Problems]
A head slider according to the present invention includes a slider and a suspension that presses the slider against a disk medium. The slider is formed to face the thin medium, and the slider is moved to the disk medium by an air flow. Formed on the inner peripheral side of the disc medium, an air inflow end formed on the air flow inflow side, an outflow end formed on the air flow out side, and an inner peripheral side of the disk medium. An inner peripheral end, an outer peripheral end formed on the outer peripheral side of the disk medium, and a head for recording / reproducing between the disk medium, and the air lubrication surface generates a positive pressure. An upper surface having a first height for the slider, the slider Along the inner and outer peripheral edges Has a virtual center axis, The upper step surface has an inner peripheral side rail formed from the inflow end toward the outflow end on the inner peripheral end side with respect to the central axis, and on the inner peripheral side of the inner peripheral side rail. A first edge is formed; The first edge is formed so as to approach the outer peripheral end from the inflow end toward the outflow end, and the first edge includes a tangent line defined at all points of the first edge and the central axis. Is formed to be larger than the absolute value of the skew angle when the slider is located on the innermost circumference on the disk medium, thereby achieving the above object.
[0033]
The air lubrication surface may have a middle surface having a second height lower than the first height.
[0034]
You may further have a negative pressure generation | occurrence | production recessed part formed so that it may be enclosed by at least any one of the said upper stage surface and the said middle stage surface.
[0035]
The upper stage surface has an outer peripheral side rail formed from the inflow end toward the outflow end on the outer peripheral end side with respect to the central axis, and a second side surface is formed on the inner peripheral side of the outer peripheral side rail. Edges are formed, The second edge is formed so as to approach the outer peripheral end from the inflow end toward the outflow end, and the second edge includes a tangent line defined at all points of the second edge and the central axis. Is formed to be larger than the absolute value of the skew angle when the slider is located on the innermost circumference on the disk medium. May .
[0036]
The upper stage surface may be formed from the inflow end side with respect to a position where the slider is pressed by the suspension.
[0037]
Another head slider according to the present invention includes a slider and a suspension that presses the slider against a disk medium, and the slider is formed to face the disk medium, and the slider is moved to the disk medium by an air flow. Formed on the inner peripheral side of the disc medium, an air inflow end formed on the air flow inflow side, an outflow end formed on the air flow out side, and an inner peripheral side of the disk medium. An inner peripheral end, an outer peripheral end formed on the outer peripheral side of the disk medium, and a head for recording / reproducing between the disk medium, and the air lubrication surface generates a positive pressure. An upper surface having a first height for, The air lubrication surface includes a middle step surface having a second height lower than a first height, and a negative pressure generating recess formed to be surrounded by at least one of the upper step surface and the middle step surface. And The slider is Along the inner and outer peripheral edges The upper surface has a cross rail formed on the inflow end side with respect to the negative pressure generating recess, and the cross rail is in the inflow end with respect to the cross rail. The edge has a notch formed on the outer peripheral end side with respect to the central axis, whereby the above object is achieved.
[0039]
The cut may have a triangular plan shape.
[0040]
The distance from the central axis to the top of the notch may be substantially equal to the distance from the central axis to the outer boundary edge of the negative pressure generating recess.
[0041]
Still another head slider according to the present invention includes a slider and a suspension that presses the slider against a disk medium. The slider is formed to face the disk medium, and the slider is moved to the disk by an air flow. An air lubrication surface for floating from the medium, an inflow end formed on the air flow inflow side, an outflow end formed on the air flow out side, and an inner peripheral side of the disk medium An inner peripheral end, an outer peripheral end formed on the outer peripheral side of the disk medium, and a head for recording / reproducing between the disk medium, and the air lubricated surface generates a positive pressure. An upper surface having a first height for The air lubrication surface includes a middle step surface having a second height lower than a first height, and a negative pressure generating recess formed to be surrounded by at least one of the upper step surface and the middle step surface. And The slider is Along the inner and outer peripheral edges The upper surface has a cross rail formed on the inflow end side with respect to the negative pressure generating recess, and the cross rail is in the inflow end with respect to the cross rail. The edge has a protruding shape formed on the inner peripheral end side with respect to the central axis, thereby achieving the above object.
[0043]
The protrusion may have a triangular plan shape.
[0044]
The distance from the central axis to the projecting shape top may be substantially equal to the distance from the center line to the inner peripheral side boundary edge of the negative pressure generating recess.
[0045]
The edge may further include a cut formed on the outer peripheral end side with respect to the central axis.
[0046]
Still another head slider according to the present invention includes a slider and a suspension that presses the slider against a disk medium. The slider is formed to face the disk medium, and the slider is moved to the disk by an air flow. An air lubrication surface for floating from the medium, an inflow end formed on the air flow inflow side, an outflow end formed on the air flow out side, and an inner peripheral side of the disk medium An inner peripheral end, an outer peripheral end formed on the outer peripheral side of the disk medium, and a head for recording / reproducing between the disk medium, and the air lubricated surface generates a positive pressure. An upper stage surface having a first height for performing, a middle stage surface having a second height lower than the first height, A negative pressure generating recess formed so as to be surrounded by at least one of the upper stage surface and the middle stage surface; The slider is Along the inner and outer peripheral edges The upper stage surface has a cross rail formed on the inflow end side with respect to the negative pressure generating recess, and the middle stage surface includes the cross rail and the negative pressure generating recess. The middle step surface is formed such that the length of the middle step surface in the slider longitudinal direction is maximum at a position closest to the inner peripheral end and is minimum at a position closest to the outer peripheral end. This achieves the above object.
[0047]
The middle step surface may be formed such that the length in the slider longitudinal direction becomes shorter from the inner peripheral end side toward the outer peripheral end side.
[0048]
Still another head slider according to the present invention includes a slider and a suspension that presses the slider against a disk medium. The slider is formed to face the disk medium, and the slider is moved to the disk by an air flow. An air lubrication surface for floating from the medium, an inflow end formed on the air flow inflow side, an outflow end formed on the air flow out side, and an inner peripheral side of the disk medium An inner peripheral end, an outer peripheral end formed on the outer peripheral side of the disk medium, and a head for recording / reproducing between the disk medium, and the air lubricated surface generates a positive pressure. An upper surface having a first height for performing, a middle surface having a second height lower than the first height, A negative pressure generating recess formed so as to be surrounded by at least one of the upper stage surface and the middle stage surface; The slider is Along the inner and outer peripheral edges The center plane has a virtual center axis, the middle surface has a cross rail formed on the inflow end side with respect to the negative pressure generating recess, and the cross rail is in the inflow end with respect to the cross rail. The edge has a notch formed on the outer peripheral end side with respect to the central axis, whereby the above object is achieved.
[0049]
Still another head slider according to the present invention includes a slider and a suspension that presses the slider against a disk medium. The slider is formed to face the disk medium, and the slider is moved to the disk by an air flow. An air lubrication surface for floating from the medium, an inflow end formed on the air flow inflow side, an outflow end formed on the air flow out side, and an inner peripheral side of the disk medium An inner peripheral end, an outer peripheral end formed on the outer peripheral side of the disk medium, and a head for recording / reproducing between the disk medium, and the air lubricated surface generates a positive pressure. An upper surface having a first height for performing, a middle surface having a second height lower than the first height, A negative pressure generating recess formed so as to be surrounded by at least one of the upper stage surface and the middle stage surface; The slider is Along the inner and outer peripheral edges The center plane has a virtual center axis, the middle surface has a cross rail formed on the inflow end side with respect to the negative pressure generating recess, and the cross rail is in the inflow end with respect to the cross rail. The edge has a protruding shape formed on the inner peripheral end side with respect to the central axis, thereby achieving the above object.
[0050]
According to the present invention, it is possible to obtain an excellent effect that the wear of the edge of the upper stage surface due to the CSS operation is suppressed, and the temporal change of the flying characteristics of the head slider can be minimized.
[0051]
Further, according to the present invention, it is possible to adjust the amount of air flow flowing into the upper surface and the negative pressure generating recess on the outer peripheral side of the air lubrication surface with respect to the center line, and the air lubrication by the skew angle during recording / reproduction. An excellent effect is obtained that it is possible to minimize the flying height fluctuation on the outer peripheral side of the surface.
[0052]
Furthermore, according to the present invention, it is possible to balance the negative pressure generated on the outer peripheral side of the air lubricated surface from the center line and the negative pressure generated on the inner peripheral side of the air lubricated surface from the center line, thereby stabilizing the slider. An excellent effect of obtaining a floating posture is obtained.
[0053]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0054]
(Embodiment 1)
FIG. 1 is a perspective view of the inside of the magnetic disk device 100 according to the first embodiment. FIG. 2 is a cross-sectional view of the magnetic disk device 100. The magnetic disk device 100 is covered with a housing cover (not shown). A suspension 14 is attached to the tip of the actuator arm 5 that is rotatably attached to the actuator shaft 20. A head slider 3 that carries a magnetic transducer or a read / write head 99 (described later in FIG. 7) is attached to the tip of each suspension 14.
[0055]
A main shaft 1 is mounted in the housing 7. A plurality of magnetic disk media 2 are rotatably attached to the main shaft 1 at intervals. The magnetic disk medium 2 rotates in the direction indicated by the arrow A together with the main shaft 1 rotated by the motor 8. Information is written on or read from the magnetic disk medium 2 by a head 99 (not shown) located in the head slider 3 and positioned by the actuator arm 5.
[0056]
Head sliders 3 are provided on both the front and back surfaces of the magnetic disk medium 2, and information is written to or read from the magnetic disk medium 2.
[0057]
Power is applied to the actuator 5 by the voice coil motor 6, and the actuator arm 5 rotates around the actuator shaft 20.
[0058]
A head slider 3 and a magnetic transducer (not shown) integrated with the head slider 3 move on the surface of the magnetic disk medium 2 so that a magnetic representation of data can be stored in any track on the magnetic disk medium 2. In the magnetic disk drive, the movement of the transducer is due to rotation around the actuator shaft 20. By rotating the actuator arm 5, the head slider 3 and the head 99 therein can be positioned on any track on the surface of the magnetic disk medium 2.
[0059]
FIG. 3 is a detailed view of one of the magnetic disk media 2 as viewed from above. As is well known as the technology of magnetic disk devices, each magnetic disk medium 2 has a row of concentric tracks on which magnetic information is recorded. The inner diameter (ID) track 11 is the innermost concentric track in which data is stored. The outer diameter (OD) track 12 is the outermost concentric track in which data is stored.
[0060]
The CSS zone 13 is formed inside the ID track 11. In the state where the rotation of the magnetic disk medium 2 is stopped, the head slider 3 stands by in contact with the CSS zone 13.
[0061]
4, 5 and 6 are schematic diagrams for explaining the CSS system. In the CSS zone 13, protrusions called bumps 2 A are periodically formed on the surface of the magnetic disk medium 2 in order to prevent the magnetic disk medium 2 and the head slider 3 from attracting each other. The height H is 10 nm.
[0062]
In order to prevent the magnetic disk medium 2 and the head slider 3 from attracting each other, the air lubrication surface 30 of the head slider 3 facing the magnetic disk medium 2 is subjected to a convex surface treatment called a crown. The dimension D3 of the crown in the first embodiment is 30 nm.
[0063]
As shown in FIG. 4, when the magnetic disk medium 2 is stopped rotating, the head slider 3 is pressed against the surface of the magnetic disk medium 2 via the pivot 15 by the suspension 14, and the pivot of the air lubrication surface 30. The position facing 15 contacts the magnetic disk medium 2.
[0064]
As shown in FIG. 5, when the magnetic disk medium 2 starts to rotate, an air flow A flows between the surface of the magnetic disk medium 2 and the air lubrication surface 30 and contacts the magnetic disk medium 2 on the air lubrication surface 30. The moving position moves in the direction of the air outflow end 42 as the rotational speed of the magnetic disk medium 2 increases.
[0065]
As shown in FIG. 6, when the rotational speed of the magnetic disk medium 2 becomes higher than a predetermined rotational speed, which is 3000 rpm in the first embodiment, the head slider 3 floats from the surface of the magnetic disk medium 2 and In a contact state, the rotation speed is increased to a constant rotational speed for recording and reproduction, which is 7200 rpm in the first embodiment.
[0066]
As described above, the portion of the air lubrication surface 30 closer to the air outflow end 42 than the pivot 15 slides in contact with the magnetic disk medium 2 every time the CSS operation is performed.
[0067]
FIG. 7 shows the shape of the air lubrication surface 30 of the head slider 3. The air lubrication surface 30 is formed on the lower surface of the head slider 3 and faces the magnetic disk medium 2. The shape of the air lubrication surface 30 is formed by molding, etching, laser cutting, ion pulverization, general-purpose machining, or other various methods.
[0068]
The air-lubricated surface 30 is formed of three stages of substantially parallel flat surfaces, that is, an upper stage surface 31, an intermediate stage surface 32, and a lower stage surface 33. In the first embodiment, the upper surface 31 is crowned with 30 nm.
[0069]
The structure of the air lubrication surface 30 will be described. The air lubrication surface 30 includes a cross rail 34 formed at predetermined intervals from the air inflow end 41, the air outflow end 42, and the inner peripheral end 43, and a predetermined interval from the air inflow end 41 and the inner peripheral end 43. The inner side rail 35 is formed to the air outflow end 42 with a space therebetween, and the outer side rail 36 is formed to the air outflow end 42 with a predetermined distance from the air inflow end 41 and the outer peripheral side end 44. A middle step surface 32 is formed.
[0070]
On the middle step surface 32, an upper step surface 31 including a cross rail 37, an inner side rail 38, and an outer side rail 39 is formed. A negative pressure generating recess 48 is formed so as to be surrounded by the middle surface 32.
[0071]
The upper stage surface 31 is formed on the air inflow end 41 side from the pivot position 45 where the head slider 3 is pressed by the suspension.
[0072]
When the magnetic disk medium 2 rotates, an air flow flows from the air inflow end 41 under the air lubrication surface 30. The pressure that acts in the direction of moving the head slider 3 away from the magnetic disk medium 2 by the pressure generated on the air lubrication surface 30 by the air flow is called positive pressure, and the pressure that acts in the direction of moving the head slider 3 closer to the magnetic disk medium 2 is negative. Called pressure.
[0073]
The read / write head 99 is usually located near the air outflow end 42 of the upper stage surface 31.
[0074]
In the first embodiment, the drop between the upper step surface 31 and the middle step surface 32 is 1 μm, and the drop between the middle step surface 32 and the lower step surface 33 is 3 μm.
[0075]
FIG. 7 shows a vertical axis 50 and a horizontal axis 51 imaginary by the head slider 3 through the pivot position 45. The angle formed by the direction of the vertical axis 50 and the sliding direction of the magnetic disk medium 2 is called a skew angle. The skew angle greatly varies between the head slider 3 and the CSS zone 13 to the ID track 11 and the OD track 12. The skew angle depends on the position where the actuator arm 5 is attached to the rotary actuator shaft 20.
[0076]
The skew angle can be positive or negative. When the actuator arm 5 is positioned so that the sliding direction of the magnetic disk medium 2 is in contact with the outer peripheral end 44 of the head slider 3, the skew angle is positive. When the actuator arm 5 is positioned so that the sliding direction corresponds to the inner peripheral end 43 of the head slider 32, the skew angle is negative.
[0077]
In the first embodiment, the rotary actuator / actuator arm 5 is installed such that the skew angle is maximized in the OD track 12 and the skew angle is minimized in the CSS zone 13. The skew angle at the OD track 12 is 14 degrees, the skew angle at the ID track 11 is -9 degrees, and the skew angle at the CSS zone 13 is -14 degrees.
[0078]
The sliding direction of the magnetic disk medium 2 in the CSS zone 13 where the magnetic disk medium 2 and the head slider 3 are in sliding contact is indicated by an arrow B in FIG.
[0079]
On the air outflow end 42 side with respect to the horizontal axis 51 imaginary in the head slider 3 through the pivot position 45, the upper peripheral surface 52 and the inner peripheral edge 52 of the inner peripheral side rail 38 configuring the upper step surface 31 are configured. The inner peripheral edge 53 of the outer peripheral side rail 39 has angles θ1 and θ2 with respect to the vertical axis 50, respectively.
[0080]
FIG. 8 shows the relationship between the flying height of the head slider 3 in the ID track 11 and the number of CSS operations. A solid line 81 in FIG. 8 shows the case where θ1 = −15 degrees and θ2 = −16 degrees are set in the first embodiment. FIG. A broken line 82 indicates a case where θ1 = 0 degrees and θ2 = 0 degrees are set.
[0081]
In the first embodiment, the skew angle at the ID track 11 is −9 degrees, and the skew angle at the CSS zone 13 is −14 degrees. The rotational speed of the magnetic disk medium 2 is constant at 7200 rpm, and the flying height is measured at the position of the head 99.
[0082]
As indicated by the broken line 82, the flying height when θ1 = 0 degrees and θ2 = 0 degrees increases as the number of CSS operations increases. On the other hand, as shown by the solid line 81, the flying height when θ1 = −15 degrees and θ2 = −16 degrees is maintained at a substantially constant value regardless of the number of CSS operations.
[0083]
The reason why the flying height when θ1 = 0 degrees and θ2 = 0 degrees increases as the number of CSS operations increases is that the inner peripheral edges 52 and 53 of the side rails 38 and 39 are formed in the CSS zone 13. This is to promote the inflow of the airflow as if the side rails 38 and 39 are tapered by being worn due to a violent collision with the bump 2A and becoming unclear.
[0084]
When θ1 = −15 degrees and θ2 = −16 degrees, the inner peripheral edges 52 and 53 are set to be smaller than the skew angle −14 degrees in the CSS zone 13, and therefore the inner peripheral edges 52 and 53 are There is no hard collision with bump 2A.
[0085]
As described above, according to the first embodiment, the angle formed between the inner peripheral edges 52 and 53 of the side rails 38 and 39 constituting the upper surface 31 and the vertical axis 50 is determined from the skew angle in the CSS zone 13. Is set to be small, it is possible to suppress wear of the inner peripheral edges 52 and 53 during the CSS operation, and it is possible to secure an excellent effect that the change in the flying height due to the number of CSS operations can be reduced. Furthermore, since the wear itself can be reduced, it is possible to reduce the adverse effect on the recording / reproducing signal due to the generation of wear powder.
[0086]
Next, the flying height variation due to the change in the skew angle during recording and reproduction will be described. Referring to FIG. 7, the edge on the air inflow end 41 side of the cross rail 37 constituting the upper stage surface 31 is formed with a front edge portion 55 and a front edge portion 56 on the outer peripheral side end 44 side from the vertical axis 50. A triangular cut 55A is formed. Further, a triangular protrusion 55B formed by the front edge portion 54 and the front edge portion 55 is formed on the inner peripheral side end 43 side from the vertical axis 50.
[0087]
As described above, the edge of the cross rail 37 on the air inflow end 41 side has a triangular shape including the vertices 55A, 55B and 55C and a triangular shape including the vertices 55A, 55B and 55D.
[0088]
A distance D1 from the vertical axis 50 to the top of the cut is substantially equal to a distance D2 from the vertical axis 50 to the outer boundary edge of the negative pressure generating recess.
[0089]
The rotation speed of the magnetic disk medium 2 during recording / reproduction in the first embodiment is constant at 7200 rpm. When the head slider 2 is on the ID track 11, the skew angle is -9 degrees, and the relative speed between the head slider 3 and the magnetic disk medium 2 is minimum. When in the OD track 12, the skew angle is 14 degrees and the relative speed is maximum. The inflow amount of the air flow to the air lubrication surface 30 is minimum at the ID track 11 and maximum at the OD track 12.
[0090]
In FIG. 7, the direction of air flow in the ID track 11 is indicated by an arrow C, and the direction of air flow in the OD track 12 is indicated by an arrow D.
[0091]
FIG. 9 shows the relationship between the skew angle and the flying height. In FIG. 9, the solid line 91 indicates the flying height of the head slider 3 according to the first embodiment, and the broken line 92 in FIG. 9 indicates the front edge of the cross rail 37. This is the flying height when it is formed by a straight line substantially parallel to the air inflow end 41.
[0092]
When the front edge of the cross rail 37 is formed by a straight line substantially parallel to the air inflow end 41 as indicated by a broken line 92, the flying height is minimized at the skew angle of -9 degrees, that is, the ID track 11, The flying height is maximized around a skew angle of 6 degrees. Compared to this, as shown by the solid line 91, when configured as in the first embodiment, the flying height at the ID track 11 becomes larger than the broken line 92, and the flying height at the OD track 12 increases. Also, the fluctuation width of the flying height of the head slider 3 is reduced by being smaller than the broken line 92.
[0093]
This will be described with reference to FIG. When the air flow colliding with the front edge 55 of the cross rail 37 passes over the cross rail 37 and then flows into the negative pressure generating recess 48, the negative pressure acts in a direction to bring the head slider 3 closer to the magnetic disk medium 2. Will occur.
[0094]
However, since the front edge 55 and the front edge 56 form a triangular cut 55A as described above, the air that collides with the front edge 55 when the head slider 3 is on the ID track 11. A part of the flow does not pass on the cross rail 37 but flows along the front edge portion 55 and flows onto the outer side rail 39 from the vicinity of the top of the triangular notch 55A.
[0095]
When the head slider 3 is on the OD track 12, a part of the air flow colliding with the front edge portion 56 does not flow onto the outer peripheral side rail 39 but flows along the front edge portion 56, and the front edge portion 55. After passing over the cross rail 37 from the triangular notch 55A formed by the front edge portion 56, it flows into the negative pressure generating recess 48.
[0096]
Accordingly, the negative pressure acting on the head slider 3 decreases and the positive pressure increases in the ID track 11 with a small air inflow amount, and the negative pressure acting on the head slider 3 increases in the OD track 12. Positive pressure decreases.
[0097]
As described above, according to the first embodiment, it is possible to increase the flying height in the ID track 11 with a small air inflow amount, and in the OD track 12 in which the flying height increases because the air inflow amount is large. Since the flying height can be reduced, the flying height fluctuation between the ID track 11 and the OD track 12 can be reduced.
[0098]
Since the positive pressure generated in the outer peripheral side rail 39 and the negative pressure generated in the negative pressure generating recess 48 are adjusted, it is possible to provide the head slider 3 with a small flying height fluctuation particularly on the outer peripheral side of the head slider 3. It becomes possible.
[0099]
Therefore, according to the first embodiment, if the head 99 is formed on the outer peripheral side of the air lubrication surface 30, the position of the head 99 is determined only by the notch 55A formed by the front edge portion 55 and the front edge portion 56. It is possible to suppress the flying height fluctuation from the magnetic disk medium 2 at.
[0100]
Furthermore, according to the first embodiment, the front edge portion 54 and the front edge portion 55 form a triangular protrusion 55B. Therefore, when the head slider 3 is on the ID track 11, the front edge portion 54 The collided air flow flows into the inner peripheral side rail 38. When the head slider 3 is on the OD track 12, a part of the air flow colliding with the front edge portion 54 flows along the front edge portion 54 without flowing into the inner peripheral side rail 38. It flows out of the air lubrication surface 30 from the peripheral end 43.
[0101]
For this reason, the negative pressure acting on the head slider 3 decreases and the positive pressure increases in the ID track 11 having a small air inflow amount, and the negative pressure acting on the head slider 3 increases in the OD track 12. , Positive pressure decreases.
[0102]
As described above, according to the first embodiment, it is possible to increase the flying height in the ID track 11 with a small air inflow amount, and in the OD track 12 in which the flying height increases because the air inflow amount is large. Since the flying height can be reduced, the flying height fluctuation between the ID track 11 and the OD track 12 can be reduced.
[0103]
Since the positive pressure generated in the inner peripheral side rail 38 and the negative pressure generated in the negative pressure generating recess 48 are adjusted, the head slider 3 is provided that has a small variation in flying height particularly on the inner peripheral side of the head slider 3. It becomes possible. In the head slider in which the head 99 is located on the inner peripheral side of the air lubrication surface 30, it is possible to suppress fluctuations in the flying height from the magnetic disk medium 2 at the position of the head 99.
[0104]
Referring to FIG. 7, the pressure adjusting portion 57 of the middle step surface 32 formed on the air outflow end 42 side of the cross rail 37 forming the upper step surface 31 has a vertical axis 50 direction as it goes from the inner periphery side to the outer periphery side. The width is formed to be small. The speed of the airflow flowing through the air lubrication surface 30 increases from the inner peripheral side end 43 toward the outer peripheral side end 44. For this reason, the positive pressure generated in the outer peripheral side rail 39 is larger than the positive pressure generated in the inner peripheral side rail 38.
[0105]
As shown in FIG. 7, the pressure adjusting unit 57 is formed so that the width in the direction of the vertical axis 50 becomes smaller from the inner peripheral side toward the outer peripheral side, so the negative pressure generated in the negative pressure generating unit 48 is It becomes large as it goes to the outer peripheral side end 44 side from the inner peripheral side end 43 side.
[0106]
The negative pressure is increased on the outer peripheral side where the positive pressure is large, and the negative pressure is decreased on the inner peripheral side where the positive pressure is small. And a stable levitation posture can be obtained.
[0107]
Further, in the first embodiment, the front edge portion 54, the front edge portion 55, and the front edge portion 56 are formed in a sawtooth shape to suppress the fluctuation of the flying height balanced between the inner peripheral side and the outer peripheral side of the air lubrication surface 30. Since this is done, combined with the effect of the pressure adjustment unit 57, the effect of obtaining a more stable flying posture is exhibited.
[0108]
(Embodiment 2)
The present invention is not limited to the shape of the air lubricating surface 30 of the first embodiment, and some problems can be overcome by the sliders shown in FIGS. 10, 11, 12, and 13.
[0109]
In the air lubrication surface 30A shown in FIG. 10, the side rails 38A and 39A forming the upper step surface 31A and the side rails 35A and 36A forming the middle step surface 32A are not formed up to the air outflow end 42, and the upper step surface on which the head 99 is located. An outflow portion rail 82 of 31A and an outflow portion rail 81 of the middle step surface 32A are formed around it.
[0110]
As a result, a positive pressure generation effect can be obtained on the outflow portion rail 82 of the upper stage surface 31A where the head 99 is located, and it can float from the magnetic disk medium 2 at a lower rotational speed. This makes it possible to suppress wear during CSS operation.
[0111]
The air lubricated surface 30B shown in FIG. 11 has the head slider 3 positioned on the OD track 12 at angles θ3 and θ4 formed by the outer peripheral edges 91 and 92 of the side rails 38B and 39B forming the upper step surface 31B with the vertical axis 50, respectively. In this embodiment, the skew angle is set larger than 14 degrees.
[0112]
As a result, not only wear during CSS operation but also wear due to accidental contact between the magnetic disk medium 2 and the head slider 3 in a state where the magnetic disk device is performing recording and reproduction can be suppressed.
[0113]
In the air lubrication surface 30C shown in FIG. 12, the inner peripheral edges 101 and 102 of the side rails 38C and 39C forming the upper step surface 31C on the air outflow end 42 side from the horizontal shaft 51 are formed by curves.
[0114]
The angle formed between the tangent line defined at all locations of the inner edges 101 and 102 and the vertical axis 50 is made smaller than the skew angle when the head slider 3 is in the CSS zone 13, which is -14 degrees in this embodiment. Therefore, it is possible to suppress wear due to the CSS operation of the inner peripheral edges 101 and 102 and to suppress a change in the flying height with time.
[0115]
As shown in FIG. 13, even if the air lubrication surface 30D is formed with a curved edge 111 on the air inflow end 41 side of the cross rail 37D that forms the upper surface 31D, the effect of suppressing the flying height fluctuation can be obtained. . Even if the pressure adjusting portion 57 of the middle step surface 32D formed on the air outflow end side of the cross rail 37D is a curved surface, the effect of stabilizing the flying posture can be obtained.
[0116]
As shown in FIG. 14, the flying height variation due to the skew angle can be suppressed by the edge 121 on the air inflow end 41 side of the cross rail 34E that forms the middle step surface 32E.
[0117]
In the first and second embodiments, the head has been described by taking a magnetic head as an example, but the head may be an optical head, for example.
[0118]
【The invention's effect】
As described above, according to the present invention, it is possible to provide a head slider that suppresses wear of the edge of the pressure generating surface and minimizes the temporal change of the flying characteristics of the head slider.
[0119]
In addition, according to the present invention, it is possible to provide a head slider that minimizes the flying height fluctuation of the head slider at the inner and outer peripheral portions of the magnetic disk medium.
[0120]
Furthermore, according to the present invention, there is an excellent effect that the flying posture of the head slider can be stabilized.
[Brief description of the drawings]
FIG. 1 is a perspective view of a magnetic disk device according to a first embodiment.
FIG. 2 is a sectional view of the magnetic disk device according to the first embodiment.
FIG. 3 is a detailed view of one of the magnetic disk media according to the first embodiment as viewed from above.
FIG. 4 is a schematic diagram for explaining a CSS system according to the first embodiment.
FIG. 5 is a schematic diagram for explaining a CSS system according to the first embodiment.
FIG. 6 is a schematic diagram for explaining a CSS system according to the first embodiment.
7 is an explanatory diagram of the shape of an air lubrication surface of the head slider according to Embodiment 1. FIG.
FIG. 8 is a graph showing the relationship between the CSS count and the flying height according to the first embodiment.
FIG. 9 is a graph showing the relationship between the skew angle and the flying height according to the first embodiment.
FIG. 10 is an explanatory diagram of the shape of the air lubrication surface of the head slider according to the second embodiment.
FIG. 11 is an explanatory diagram of the shape of an air lubrication surface of another head slider according to the second embodiment.
12 is an explanatory diagram of the shape of an air lubrication surface of still another head slider according to the second embodiment. FIG.
13 is an explanatory diagram of the shape of an air lubrication surface of still another head slider according to Embodiment 2. FIG.
FIG. 14 is an explanatory diagram of the shape of an air lubrication surface of still another head slider according to the second embodiment.
[Explanation of symbols]
30 Air-lubricated surface
31 Upper surface
41 Inflow end
42 Outflow end
43 Inner edge
44 Outer edge
50 central axis
52 1st edge

Claims (16)

A slider,
A suspension for pressing the slider against a disk medium,
The slider is formed so as to face the disk medium, and an air lubricating surface for floating the slider from the disk medium by an air flow;
An inflow end formed on a side into which the airflow flows,
An outflow end formed on the side from which the airflow flows out;
An inner peripheral end formed on the inner peripheral side of the disk medium;
An outer peripheral end formed on the outer peripheral side of the disk medium;
A head for recording and reproduction with the disk medium,
The air lubrication surface has an upper surface having a first height for generating a positive pressure,
The slider has a central axis that is hypothesized along the inner and outer peripheral ends of the slider;
The upper step surface has an inner peripheral side rail formed from the inflow end toward the outflow end on the inner peripheral end side with respect to the central axis, and on the inner peripheral side of the inner peripheral side rail. A first edge is formed;
The first edge is formed so as to approach the outer peripheral end from the inflow end toward the outflow end,
The first edge is an absolute value of a skew angle when an angle formed between a tangent line defined at all points of the first edge and the central axis is located on the innermost circumference on the disk medium. The head slider is formed to be larger.   The head slider according to claim 1, wherein the air-lubricated surface has a middle step surface having a second height lower than the first height.   The head slider according to claim 2, further comprising a negative pressure generating recess formed so as to be surrounded by at least one of the upper stage surface and the middle stage surface. The upper stage surface has an outer peripheral side rail formed from the inflow end toward the outflow end on the outer peripheral end side with respect to the central axis, and a second side surface is formed on the inner peripheral side of the outer peripheral side rail. Edges are formed,
The second edge is formed so as to approach the outer peripheral end from the inflow end toward the outflow end,
The second edge is based on an absolute value of a skew angle when an angle formed between a tangent line defined at all points of the second edge and the central axis is located on the innermost circumference on the disk medium. The head slider according to claim 1, wherein the head slider is formed to be larger.   The head slider according to claim 1, wherein the upper stage surface is formed from the inflow end side with respect to a position where the slider is pressed by the suspension. A slider,
A suspension for pressing the slider against a disk medium,
The slider is formed so as to face the disk medium, and an air lubricating surface for floating the slider from the disk medium by an air flow;
An inflow end formed on a side into which the airflow flows,
An outflow end formed on the side from which the airflow flows out;
An inner peripheral end formed on the inner peripheral side of the disk medium;
An outer peripheral end formed on the outer peripheral side of the disk medium;
A head for recording and reproduction with the disk medium,
The air lubrication surface has an upper surface having a first height for generating a positive pressure,
The air-lubricated surface has a second step surface having a second height lower than the first height;
A negative pressure generating recess formed so as to be surrounded by at least one of the upper stage surface and the middle stage surface;
The slider has a central axis that is hypothesized along the inner and outer peripheral ends of the slider;
The upper stage surface has a cross rail formed on the inflow end side with respect to the negative pressure generating recess,
The cross rail has an edge formed on the inflow end side with respect to the cross rail,
The head slider has a notch formed on the outer peripheral end side with respect to the central axis. The head slider according to claim 6 , wherein the cut has a triangular plane shape. The head slider according to claim 6 , wherein a distance from the central axis to the top of the notch is substantially equal to a distance from the central axis to an outer peripheral boundary edge of the negative pressure generating recess. A slider,
A suspension for pressing the slider against a disk medium,
The slider is formed so as to face the disk medium, and an air lubricating surface for floating the slider from the disk medium by an air flow;
An inflow end formed on a side into which the airflow flows,
An outflow end formed on the side from which the airflow flows out;
An inner peripheral end formed on the inner peripheral side of the disk medium;
An outer peripheral end formed on the outer peripheral side of the disk medium;
A head for recording and reproduction with the disk medium,
The air lubrication surface has an upper surface having a first height for generating a positive pressure,
The air-lubricated surface has a second step surface having a second height lower than the first height;
A negative pressure generating recess formed so as to be surrounded by at least one of the upper stage surface and the middle stage surface;
The slider has a central axis that is hypothesized along the inner and outer peripheral ends of the slider;
The upper stage surface has a cross rail formed on the inflow end side with respect to the negative pressure generating recess,
The cross rail has an edge formed on the inflow end side with respect to the cross rail,
The head slider has a protruding shape formed on the inner peripheral end side with respect to the central axis. The head slider according to claim 9 , wherein the protruding shape has a triangular shape in plan view. The head slider according to claim 9 , wherein a distance from the central axis to the projecting shape top is substantially equal to a distance from the center line to an inner peripheral side boundary edge of the negative pressure generating recess. The head slider according to claim 9 , wherein the edge further has a cut formed on the outer peripheral end side with respect to the central axis. A slider,
A suspension for pressing the slider against a disk medium,
The slider is formed so as to face the disk medium, and an air lubricating surface for floating the slider from the disk medium by an air flow;
An inflow end formed on a side into which the airflow flows,
An outflow end formed on the side from which the airflow flows out;
An inner peripheral end formed on the inner peripheral side of the disk medium;
An outer peripheral end formed on the outer peripheral side of the disk medium;
A head for recording and reproduction with the disk medium,
The air lubricated surface has an upper surface having a first height for generating a positive pressure;
A middle surface having a second height lower than the first height;
A negative pressure generating recess formed so as to be surrounded by at least one of the upper stage surface and the middle stage surface;
The slider has a central axis that is hypothesized along the inner and outer peripheral ends of the slider;
The upper stage surface has a cross rail formed on the inflow end side with respect to the negative pressure generating recess,
The middle surface is formed between the cross rail and the negative pressure generating recess,
The head slider is formed so that the length in the slider longitudinal direction of the middle step surface is maximized at a position closest to the inner peripheral end and is minimum at a position closest to the outer peripheral end. 14. The head slider according to claim 13 , wherein the middle step surface is formed such that a length in a longitudinal direction of the slider becomes shorter from the inner peripheral end side toward the outer peripheral end side. A slider,
A suspension for pressing the slider against a disk medium,
The slider is formed so as to face the disk medium, and an air lubricating surface for floating the slider from the disk medium by an air flow;
An inflow end formed on a side into which the airflow flows,
An outflow end formed on the side from which the airflow flows out;
An inner peripheral end formed on the inner peripheral side of the disk medium;
An outer peripheral end formed on the outer peripheral side of the disk medium;
A head for recording and reproduction with the disk medium,
The air lubricated surface has an upper surface having a first height for generating a positive pressure;
A middle step surface having a second height lower than the first height;
A negative pressure generating recess formed so as to be surrounded by at least one of the upper stage surface and the middle stage surface;
The slider has a central axis that is hypothesized along the inner and outer peripheral ends of the slider;
The middle stage surface has a cross rail formed on the inflow end side with respect to the negative pressure generating recess,
The cross rail has an edge formed on the inflow end side with respect to the cross rail,
The head slider has a notch formed on the outer peripheral end side with respect to the central axis. A slider,
A suspension for pressing the slider against a disk medium,
The slider is formed so as to face the disk medium, and an air lubricating surface for floating the slider from the disk medium by an air flow;
An inflow end formed on a side into which the airflow flows,
An outflow end formed on the side from which the airflow flows out;
An inner peripheral end formed on the inner peripheral side of the disk medium;
An outer peripheral end formed on the outer peripheral side of the disk medium;
A head for recording and reproduction with the disk medium,
The air lubricated surface has an upper surface having a first height for generating a positive pressure;
A middle step surface having a second height lower than the first height;
A negative pressure generating recess formed so as to be surrounded by at least one of the upper stage surface and the middle stage surface;
The slider has a central axis that is hypothesized along the inner and outer peripheral ends of the slider;
The middle stage surface has a cross rail formed on the inflow end side with respect to the negative pressure generating recess,
The cross rail has an edge formed on the inflow end side with respect to the cross rail,
The head slider has a protruding shape formed on the inner peripheral end side with respect to the central axis.

Images