JPH1083644A - Floating type magnetic head - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress sticking of dust to a surface of an air bearing and to obtain a stable floating characteristic in a floating magnetic head in which a pair of side rail and cross rail is formed on the surface of an air bearing of a head slider. SOLUTION: A pair of side slopes 7, 7 crossing to an air bearing surface S, having a sweepback angle θ for flow of air, and opened to an air outflow end side is provided concavely at the end plane T of an air inflow side of a head slider 1. Then, a pair of edges E, E formed by crossing both side slopes 7, 7 and the end plane T of an air inflow side is provided at more inner side than the upper stream region of a pair of side rails 6, 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flying magnetic head mounted on a hard disk drive or the like.

[0002]

2. Description of the Related Art Generally, in a hard disk drive, a disk (11) rotating at a high speed as shown in FIG.
The signal is recorded and reproduced while the magnetic head (12) attached to the tip of the swing arm (13) keeps a floating state with respect to the signal recording surface. Such a floating magnetic head (1
As 2), a negative pressure type magnetic head as shown in FIG. 14 has been proposed (Japanese Patent Publication No. 56-52380 [G11B17 / 32]). In the magnetic head, a head slider (14) on which a head element (2) and a plurality of pads (3) are formed is provided with an air bearing surface for generating a levitation force of an appropriate magnitude on a surface facing the disk. S is formed.

That is, a slope (15) is formed on the air bearing surface S on the side of the air inflow end, and a pair of side rails (17) (17) extending parallel to each other along the direction of air flow.
And a cross rail (16) for connecting the side rails (17) and (17) to each other at an end on the air inflow side. As a result, the central recess (1) is provided between both side rails (17) and (17).
8) will be formed. Therefore, the disk surface and the slope
The air flowing into the space (15) passes through the cross rail (16), and then flows along the side rails (17) and (17) and the central concave portion (18). As a result, the side rails (17) and (17) become positive pressure areas, and the central concave portion (18) becomes a negative pressure area. As a result,
The magnetic head has an elastic pressing force by the swing arm (13), a positive pressure acting on the side rails (17) (17) of the head slider (14), and a central recess (9) of the head slider (14). The floating position in which the acting negative pressure is balanced is maintained (see FIG. 15).

[0004]

As shown in FIG. 17, in a hard disk drive, the magnetic head (12) is moved between the moving end Pi on the inner circumference side of the disk and the outer circumference of the disk by the swing of the arm (13). When the magnetic head 12 reciprocates between the moving ends Po, the angle formed by the attitude of the magnetic head 12 with respect to the disk circumferential direction, that is, the skew angle θ changes.
Also, since the disk (11) rotates at a constant angular velocity, the relative speed of the magnetic head (12) with respect to the disk (11) varies from the moving end Pi on the inner peripheral side of the disk to the moving end on the outer peripheral side of the disk. It will increase as we move to Po.

FIG. 16A shows a skew angle Skew (de)
g) as a parameter, the relative speed Spe of the magnetic head
This shows the relationship between ed (m / s) and the flying height FH (nm). Here, the skew angle Skew is defined as zero when the attitude of the magnetic head (12) coincides with the disk circumferential direction in FIG. 17, and is positive and counterclockwise when the swing arm (13) is rotated clockwise. The case of turning is regarded as negative. or,
The flying height FH is determined by the head slider (14) as shown in FIG.
Of the disk (11) from the surface. As is clear from FIG. 16A, the flying height FH increases as the relative speed Speed increases. FIG. 16B shows the relationship between the skew angle Skew and the flying height FH using the relative speed Speed of the magnetic head with respect to the disk as a parameter. When the skew angle fluctuates around zero, the flying height is reduced. It has changed significantly.

As described above, in the conventional flying magnetic head, the flying height changes greatly with the fluctuation of the skew angle and the relative speed of the magnetic head. This causes a problem that the recording / reproducing sensitivity of the signal is significantly changed.

In a conventional flying magnetic head,
As shown in FIG. 4, due to the negative pressure generated in the central concave portion (18),
The air flowing outside the head slider (14) is
8), the streamlines of the air flowing along the air bearing surface converge from the upstream side to the downstream side as indicated by arrows in the figure. Therefore, dust in the air flowing in through the slope (15) of the head slider (14) not only enters the gap between the disk surface and the side rails (17) (17), but also moves to the head slider (1). The dust (9) in the air sucked from the outside of ()) may also enter the gap and adhere to the air bearing surface. If the dust (9) adheres to the air bearing surface in this manner, the dust (9) comes into contact with the signal surface of the disk, and there is a problem in that recording and reproduction of signals are hindered.

SUMMARY OF THE INVENTION An object of the present invention is to provide a flying magnetic head capable of suppressing adhesion of dust to an air bearing surface and obtaining stable flying characteristics.

[0009]

A flying magnetic head according to the present invention comprises a head slider (1) having an air bearing surface S to face a disk-shaped recording medium and a head element (2) formed thereon. A pair of side rails (6) and (6) are formed on the air bearing surface S so as to extend in the direction of air flow. A cross rail (5) connected to each other is formed. A pair of side slopes, which intersect with the air bearing surface S and have a receding angle θ with respect to the flow of air, open toward the air outflow end side at the air inflow side end surface T of the head slider (1). (7) (7) is recessed.

In the above-mentioned floating magnetic head, air flowing into the air bearing surface of the head slider (1) first strikes a pair of side slopes (7) and (7) and flows along the side slopes. In the process, some air flows into the surface of the side rails (6) and (6), and the remaining air flows out of the side slope (7) to the outside of the head slider (1) (see FIG. 3). ). Therefore, at least a part of the dust contained in the inflowing air is discharged to the outside of the head slider (1) by riding on the flow of the air.

Further, the streamline distribution formed along the air bearing surface of the head slider (1) as described above is changed from a conventional distribution converged at the center of the air bearing surface to a distribution diffused at least on the upstream side. As a result, the change in the flying height due to the change in the relative speed of the magnetic head with respect to the recording medium and the change in the skew angle are reduced, and the flying characteristics are improved. This point is proved by a computer simulation described later.

In a specific construction, both side slopes (7)
A pair of edges E, E formed by (7) intersecting with the end face T on the air inflow side are provided inside the upstream regions of the pair of side rails (6), (6). This allows all of the air flowing into the side rails (6) (6) to flow along the side slopes (7) (7), thereby allowing more air to flow out of the head slider (1). Can be done. As a result, adhesion of dust is more effectively suppressed.

More specifically, the receding angle θ is 30 ° to 60 °.
The angle is set within the range of °, most preferably at 45 °. Thereby, the flying characteristics are further improved. This point is also proved by a computer simulation described later.

[0014]

According to the flying magnetic head of the present invention, it is possible to effectively prevent dust from adhering to the air bearing surface and to obtain stable flying characteristics.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below with reference to the drawings. The flying magnetic head according to the present invention has a head slider shown in FIGS.
It has (1). The head slider (1) has a pair of side rails (6) and (6) on the air bearing surface S and a cross rail (6) that connects the two side rails (6) and (6) to each other at an end on the air inflow side. 5), whereby a central concave portion (8) serving as a negative pressure region is formed between both side rails (6) and (6). The cross rail (5) has a front slope (4) for introducing air at the end on the air inflow side.

Further, the end surface T of the head slider 1 on the air inflow side is orthogonal to the air bearing surface S and expands toward the air outflow end side with a certain retreat angle θ with respect to the flow of air. A pair of side slopes (7) (7) are recessed.
Here, a pair of edges E, E formed by crossing the side slopes (7) and (7) with the end face T on the air inflow side, is located inside the upstream area of the pair of side rails (6) and (6). It is provided in. The receding angle θ is set in the range of 30 ° to 60 °, most preferably 45 °.

In the above-mentioned floating magnetic head, as shown in FIG. 3, a streamline distribution on the air bearing surface shows that the air flowing into the air bearing surface of the head slider (1) firstly has a pair of side slopes. (7) According to (7), it flows along the side slope. In the process, a part of the air flows into the surface of the side rails (6) and (6), and the remaining air flows out of the side slope (7) to the outside of the head slider (1). Therefore, at least a part of the dust contained in the inflowing air is discharged to the outside of the head slider (1) by riding on the flow of the air.

FIGS. 5 and 6 show a head slider model of a computer simulation performed for confirming the effect on the flying characteristics of the flying magnetic head of the present invention. The length A of the head slider (1) along the air flow direction is 2.032 mm, the width B in the disk radial direction is 1.6 mm, and the head slider is rotated during rotation of the disk.
The radial distance R to the center of (1) is 22.86 mm.
The disk rotation speed is 5400 rpm. The pressing force of the magnetic head against the disk signal surface is 3.5 g.

In the computer simulation, FIG.
As shown in the figure, while keeping the receding angle θ of the side slope (7) at 45 °, the depth of the side slope (7) is increased by a pitch a (0.1 mm).
5 models changed to 5 types in ,,,,
As shown in FIG. 6, five models ',' in which the retreat angle of the side slope (7) is changed to five types defined by the distances b (0.3 mm) and c (0.1 mm) in the figure. ',',
′, The flying height FH was calculated under the conditions described below. In addition, the flying height FH was similarly calculated for a conventional model having no side slope formed on the head slider. The computer simulation is based on a well-known method based on the Reynolds equation (for example,
(Vol. C, Vol. 53, No. 487, Showa 62-3, "Analysis of Thin Film Gas Lubrication Characteristics Based on Boltzmann Equation").

The graphs in FIGS. 7 to 12 show the results of the above computer simulation, in which the graphs in FIGS.
The horizontal axis indicates the depth CORNER45 (mm) of the side slope (7), the vertical axis indicates the flying height FH (nm), and the skew angle skew (de)
g) as a parameter, the levitation characteristics of each model shown in FIG. 5 are shown, and FIG. 7 shows the relative speed of 7.2 (m / m).
FIG. 8 shows a relative speed of 14.4 (m / sec), and FIG.
Is a case where the relative speed is set to 21.5 (m / sec).

As is clear from the graphs of FIGS. 7 to 9, at any relative speed, the flying height FH decreases as the depth CORNER 45 of the side slope increases, but the skew angle skew changes. The variation width of the flying height FH is small, and it can be seen that the greater the depth of the side slope, the more stable flying characteristics can be obtained. In particular, when the depth of the side slope exceeds 0.3 mm, as shown in FIGS. 1 and 2, the front edges E, E of the side slopes (7) and (7) are aligned with the side rail (6).
When moving inward from the upstream region of (6), the change width of the flying height FH accompanying the fluctuation of the skew angle skew is sharply reduced as shown in FIGS. 7 to 9, and a practically acceptable flying characteristic is obtained. Also, comparison of these graphs shows that as the depth of the side slope increases, the change in the flying height with respect to the change in the relative speed decreases.

On the other hand, FIG. 10 to FIG.
RNER ANGLE (deg), take the flying height FH (nm) on the vertical axis,
With the skew angle skew (deg) as a parameter, FIG.
FIG. 1 shows the flying characteristics of each model shown in FIG.
0 indicates a relative speed of 7.2 (m / sec), FIG. 11 indicates a relative speed of 14.4 (m / sec), and FIG. 12 indicates a relative speed of 21.5.
(m / sec). As is clear from these graphs, the sweep angle CO
When the RNERANGLE is in the range of 30 ° to 60 °, the change width of the flying height FH due to the fluctuation of the skew angle skew is small, and further, when the sweepback angle CORNER ANGLE is 45 °, the change width of the flying height FH is minimum. It can be seen that stable flying characteristics can be obtained.

As described above, according to the flying magnetic head of the present invention, the head slider (1) has a pair of side slopes.
(7) By forming (7), the adhesion of dust to the air bearing surface can be effectively suppressed, and a stable flying characteristic can be obtained.

The description of the above embodiments is for the purpose of explaining the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope thereof.
In addition, the configuration of each part of the present invention is not limited to the above-described embodiment, and it goes without saying that various modifications can be made within the technical scope described in the claims. For example, head slider (1)
The side rails (6) are not limited to those having a constant width as shown in FIG. 1, but may be formed as side rails (61) having a narrow central portion as shown in FIG. The rail (61) is composed of an upstream rail section (62) whose width decreases from the upstream side to the downstream side, and a downstream rail section (63) whose width increases from the upstream side to the downstream side. A center recess (8) is formed inside the side rails (61) and (61), and a pair of side recesses (81) and (81) are formed outside. Further, the side slope (7) is not limited to a flat surface, but may be formed into a curved surface.

[Brief description of the drawings]

FIG. 1 is a perspective view of a flying magnetic head according to the present invention.

FIG. 2 is a plan view of the flying magnetic head.

FIG. 3 is a diagram showing a flow of air on an air bearing surface of the flying magnetic head.

FIG. 4 is a diagram showing an air flow on an air bearing surface of a conventional flying magnetic head.

FIG. 5 is a plan view showing a head slider model used for computer simulation.

FIG. 6 is a plan view illustrating another head slider model.

FIG. 7 is a graph showing a change in a flying height with respect to a depth of a side slope.

FIG. 8 is a graph showing the same as above at other relative speeds.

FIG. 9 is a graph of the same as above at still another relative speed.

FIG. 10 is a graph showing a change in a flying height with respect to a retreat angle of a side slope.

FIG. 11 is a graph showing the same as above at other relative speeds.

FIG. 12 is a graph showing the same as above in still another relative speed.

FIG. 13 is a plan view of a head slider representing another embodiment of the present invention.

FIG. 14 is a perspective view of a conventional floating magnetic head.

FIG. 15 is a diagram illustrating a flying height of a head slider.

FIG. 16 is a graph showing flying characteristics of a conventional head slider.

FIG. 17 is a plan view illustrating a main part of the hard disk drive.

[Explanation of symbols]

 (1) Head slider (2) Head element (3) Pad (4) Front slope (5) Cross rail (6) Side rail (7) Side slope (8) Central recess

Claims (4)

[Claims] 1. A head slider (1) having an air bearing surface S to face a disk-shaped recording medium is provided with a head element.
A pair of side rails (6) and (6) are formed on the air bearing surface S so as to extend in the air flow direction, and both side rails (6) and (6) are formed. The head slider is a floating type magnetic head in which a cross rail (5) connecting the ends to the air inflow side is formed.
(1) A pair of side slopes (7) which intersects with the air bearing surface S and expands toward the air outflow end side with a retreat angle θ with respect to the air flow on the end surface T on the air inflow side. (7) A flying magnetic head characterized in that it is recessed. 2. A pair of edges E, E formed by intersecting both side slopes (7) and (7) with the end face T on the air inflow side, form a pair of side rails (6) and (6) from an upstream region. 2. The flying magnetic head according to claim 1, wherein the magnetic head is also provided inside. 3. The flying magnetic head according to claim 1, wherein the receding angle θ is in a range of 30 ° to 60 °. 4. The flying magnetic head according to claim 3, wherein the receding angle θ is 45 °.