JP2002358744A - Floating type magnetic head slider - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a floating type magnetic head slider which is capable of preventing the attraction of ABSs and a magnetic disk brought about by the friction force between pads and the magnetic disk in starting and has a stable floating characteristic. SOLUTION: Recessed parts are formed between the pads and the ABSs along the outer edges of the pads, by which the attraction to the magnetic disk can be averted even if the pad height based on the ABSs is lowered. The positions of the pads can be disposed near the air outflow end ABSs and the inclination of the slider can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head slider for a magnetic disk drive, and more particularly to a high recording density and high reliability used for a magnetic disk drive of a contact start / stop system (hereinafter referred to as a CSS system). The present invention relates to a floating type magnetic head slider suitable for the present invention.

[0002]

2. Description of the Related Art In recent years, there has been a demand for a flying type magnetic head slider having a reduced flying height and a high reliability for an interface between a magnetic head and a magnetic disk in order to cope with a higher recording density of a magnetic disk drive. It has become even more demanding. In the magnetic disk device of the CSS system, when the magnetic disk device is stopped,
A magnetic head slider incorporating a magnetic head element contacts a magnetic disk. And, when recording and reproducing information,
The airflow generated on the surface of the magnetic disk rotating at high speed causes the magnetic head slider to float with a small gap from the magnetic disk surface.

The magnetic head slider has an air bearing surface that receives an airflow generated on the surface of the magnetic disk by rotation of the magnetic disk.
ace; hereinafter, referred to as ABS). At the time of recording / reproducing information, the magnetic head slider supported by the suspension flies above the surface of the magnetic disk by the air flowing into the ABS. That is, the magnetic head slider is in contact with the surface of the magnetic disk when the rotation of the magnetic disk is stopped, and when the magnetic disk rotates, it floats by receiving the airflow generated by the rotation. The magnetic head slider moves in the radial direction on the magnetic disk surface while being supported by the suspension, and records and reproduces information by causing the magnetic head element attached to the ABS to face a predetermined track of the magnetic disk.

The CSS type magnetic head slider can ensure high flying stability and a small flying height, but when the magnetic disk stops rotating, the ABS comes into contact with the magnetic disk,
When the magnetic disk drive is started and stopped, sliding between the magnetic disk and the ABS of the magnetic head slider occurs. For this reason, a protective film made of a hard material such as carbon is provided on the recording layer facing the magnetic head slider of the magnetic disk, and the friction between the ABS of the magnetic head slider and the protective film is reduced at the time of starting and stopping to reduce the friction of the protective film. A lubricating layer is formed by applying a lubricant for reducing abrasion and improving the durability of the magnetic disk. Although the wear of the protective film is reduced by the presence of the lubricating layer, on the other hand, the magnetic disk and the slider are attracted by the surface tension of the lubricant at the time of stoppage, and the magnetic disk may not start rotating.

In recent years, in order to realize a low flying height of a magnetic head slider in response to an increase in recording density of a magnetic disk drive,
The surface of a magnetic disk has been smoothed, and the problem of start-up failure due to adsorption due to the surface tension of a lubricant has been greatly highlighted as a major cause of operation failure. Hereinafter, a conventional flying magnetic head slider will be described with reference to FIG. As shown in FIG. 4, in the conventional flying magnetic head slider, in order to reduce the attraction between the magnetic head slider 20 and the magnetic disk 10,
The ABS 23 on the air inflow end (left end in FIG. 4) 6 of the slider 20 to which the magnetic head element 5 is attached and the ABS 23 on the air outflow end (right end in FIG. 4) 7 are respectively provided on the ABS 23. A plurality of pads 29, 28 protruding from the 24 by a predetermined height were also formed. Thus, when the rotation of the magnetic disk 10 is stopped,
The contact area between the surface of the slider 20 and the ABS 23, 24 of the slider 20 is reduced to reduce the frictional force due to the contact.

However, when the contact area between the surface of the pad 28 and the surface of the magnetic disk 10 is reduced, the pads 29, 28 wear more when the magnetic disk device is stopped and restarted, or the pad 29, 28 Magnetic disk 1
The contact pressure with zero increases. As a result, the magnetic disk 1
0 may deteriorate the lubricity of the surface and wear the surface of the magnetic disk 10. For this measure, the contact area between the pads 29 and 28 and the magnetic disk 10 must be increased. In addition, AB of the magnetic head slider 20
In order to prevent the magnetic disks 10 from being attracted to the S 23 and S 24, the meniscus 2 generated by the surface tension of the lubricant 21 applied to the magnetic disk 10 as shown in FIG.
Sufficient heights of the pads 29 and 28 are required so that the influence of 2 (curved surface of the surface of the lubricant 21 due to the wetting angle) is eliminated.

FIG. 5 is a side view showing a state in which the magnetic head slider 20 is tilted about the air outflow side pad 28 as a fulcrum when the magnetic disk starts rotating due to the attraction force or frictional force between the magnetic head slider and the magnetic disk. As shown in FIG. 5, the magnetic head slider 20 is pulled in the rotational direction of the magnetic disk 10 and rotates, and the rotational moment in the rotational direction generated by the frictional force applied to the pad 28 at the time of starting or stopping causes the magnetic head slider 20 to move toward the air outflow end 7 side. ABS 24 may come into planar contact with the magnetic disk 10. When this phenomenon occurs, the frictional force between the magnetic head slider 20 and the magnetic disk 10 and the attraction force of the lubricant by the meniscus 12 increase, so that the magnetic head slider 20 cannot move away from the magnetic disk 10 at the time of starting or stopping, and The disk 10 is easily broken.

In particular, in a magnetic disk drive using a magnetic disk 10 having good smoothness in order to realize a low flying height of the magnetic head slider 20, the frictional force and the lubricating force of the lubricant are increased, which is a serious problem. For this reason, the magnetic head slider 20 assumes a posture inclined with the pad 28 as a fulcrum, and the ABS 24 on the air outflow end side is
Preventing contact with the surface is an important issue for ensuring the reliability of the magnetic disk drive.

The main factor of the fluctuation of the flying height of the magnetic head slider is a decrease in the pressure of the air flowing into the ABS, that is, the atmospheric pressure. Specifically, when the magnetic disk device is used in high altitudes or in an aircraft, the flying height decreases because the atmospheric pressure is reduced. When the flying height decreases, a problem occurs in that the magnetic head slider and the magnetic disk come into contact with each other and are damaged. Reducing the flying height reduction due to the pressure drop realizes a low flying height of the magnetic head slider in a stable operation and avoids contact between the magnetic head slider and the magnetic disk to ensure the reliability of the magnetic disk device. This is an important task for the purpose.

[0010]

In order to increase the recording density of a magnetic disk drive, the flying height of a magnetic head element is reduced as much as possible to reduce spacing loss (gap loss) with a magnetic disk. Is required. For this purpose, it is necessary to set the height of the pad so that the flying height of the pad during flying is higher than the flying height of the magnetic head element. When the flying height of the pad portion is lower than the flying height of the magnetic head element portion, if the flying height of the magnetic head element portion is reduced, the pad portion comes into contact with the magnetic disk and stable flying cannot be secured.

Also, at the time of starting or stopping, the magnetic friction between the pad and the surface of the magnetic disk causes the magnetic head slider to tilt with the pad serving as a fulcrum and the direction of the air outflow end decreases. For this reason, the ABS of the magnetic head slider comes into contact with the magnetic disk, causing a problem of suction. In order to prevent such a tilt of the slider, the position where the pad is formed is set to ABS.
It is conceivable to bring it closer to the air outflow end. However, when the pad is formed closer to the air outflow end, the distance between the magnetic head element and the pad becomes shorter, so that the flying height of the magnetic head element becomes higher than the flying height of the pad. Will increase. For this reason, it is necessary that the pad formation position is a distance within a certain range from the air outflow end of the ABS of the slider so that this problem does not occur.

In other words, a measure for making the flying height of the pad portion higher than the flying height of the magnetic head element portion with the pad formation position being closer to the air outflow end of the ABS includes the air inflow end of the magnetic head slider. To increase the difference between the floating amount of the air and the floating amount at the air outflow end (hereinafter, referred to as pitch), and to lower the height of the pad. As described above, in order to realize a stable and low flying height of the magnetic head in the CSS type magnetic disk drive, the flying height and the flying attitude depend on the atmospheric pressure, the rotation speed, the seek operation, and the skew angle. It is necessary to design a low-pitch magnetic head slider ABS that can reduce the performance. On the other hand, in order to reduce the spacing loss, the need to increase the pitch as described above necessitates a restriction on the low pitch in the ABS design. As described above, there is a problem that the difference between the ABS and the pad height cannot be reduced in order to obtain the optimum ABS pitch.

When the height of the pad is reduced, the meniscus curved surface is generated due to the surface tension of the lubricant, so that the magnetic disk and the slider are attracted to each other, and the original function of the pad is not fulfilled. When the lubricant is thinned to reduce the meniscus due to the surface tension, the lubricating property deteriorates, and the pad surface and the magnetic disk surface are worn, so that there is a problem that the reliability cannot be secured.

SUMMARY OF THE INVENTION An object of the present invention is to provide a flying magnetic head slider that can maintain a predetermined pad height even if the pad height based on ABS is lowered.

[0015]

According to the present invention, there is provided a flying-type magnetic head slider for recording or reproducing information at a predetermined position on the surface of a magnetic disk when the magnetic disk serving as an information recording medium rotates. A facing the disk
The magnetic head attached to the BS is floated by the inflowing air and moved in the radial direction of the magnetic disk. When the magnetic disk is stopped, the pad in contact with the magnetic disk moves downward by a predetermined height from the ABS. A magnetic head slider provided so as to protrude, wherein a concave portion is formed on an outer periphery of the pad in the ABS.

According to this configuration, by providing the concave portion on the outer periphery of the pad, it is possible to secure a predetermined pad height that does not cause suction when starting or stopping even if the pad height based on ABS is reduced. . As a result, even if the flying height of the magnetic head slider is reduced, adsorption to the magnetic disk can be avoided.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of a flying magnetic head slider according to the present invention will be described below with reference to the accompanying drawings.

<< Embodiment >> FIG. 1A is a bottom view of a magnetic head slider according to an embodiment of the present invention, as viewed from a surface facing a magnetic disk surface. FIG. 1B is a side sectional view showing the relationship between the magnetic head slider and the magnetic disk when the rotation of the magnetic disk is stopped. 1A and 1B, the surface of the magnetic head slider 1 facing the magnetic disk 10 has an air inflow side A on the air inflow end 6 side.
An air outflow side ABS 4 and an air outflow end side pad 8 are formed on the BS 3 and the air inflow end side pad 9 and on the air outflow end 7 side, respectively. And ABS 3 and ABS 4
An annular recess 11 is formed between the pad 9 and the pad 9 on each side along the outer edge of the pad 8,9. A magnetic head element 5 is incorporated in a part of the air outflow end ABS 4 of the magnetic head slider 1.

FIG. 2 is a side view showing a state in which the magnetic head slider flies during rotation of the magnetic disk. In this figure, in order to make the explanation easy to understand, the inclination angle is exaggerated and shown larger than the actual one. In FIG. 2, with the rotation of the magnetic disk 10 indicated by the arrow 2, the magnetic head slider 1
Rises at an angle a by the airflow flowing into the ABS 3 and the ABS 4. Since the flying height of the air inlet side 6 is larger than that of the air outlet side 7, the magnetic head element 5
Is closer to the lowermost end.

The flying height h0 of the magnetic head element 5 from the magnetic disk 10 is required to be small in order to reduce the spacing loss of the head 5. Therefore, the magnetic head slider 1 needs to operate on the magnetic disk 10 which is as smooth as possible. However, if a smooth magnetic disk 10 is used, the magnetic head slider 1 and the magnetic disk 10 may be attracted by the surface tension of the lubricant during the CSS operation. For this reason, it is necessary to secure the height of the pad 8 that comes into contact with the magnetic disk 10 during the CSS operation to such an extent that suction does not occur. Here, in a magnetic disk drive using a magnetic head slider in which the flying height h1 of the pad 8 is smaller than the flying height h0 of the magnetic head element 5, the flying attitude becomes unstable due to the contact between the magnetic disk 10 and the pad 8. Recording and playback failures. In the worst case, a crash between the magnetic head slider 1 and the magnetic disk 10 is caused. Therefore, the flying height h1 of the pad 8 needs to be larger than the flying height h0 of the magnetic head element 5.

FIG. 3 is a partially enlarged view showing the detailed structure of the pad portion of the magnetic head slider according to the present embodiment. As shown in FIG. 3, in the magnetic head slider of the embodiment, a concave portion 11 having a depth p2 from the ABS 4 is provided on the outer periphery of the cylindrical pad 8. The specific size of the depth p2 of the concave portion varies depending on the type of the lubricant, but is 5n on average.
It is preferably about m to 500 nm. With this configuration, even when the safe height p1 at which the lower surface of the pad 8 and the magnetic disk 10 do not stick to each other is maintained, the downward protruding height p3 of the pad 8 from the lower surface of the ABS 4 is maintained. It can be lower than the conventional one.

In the magnetic head slider according to the present embodiment, the position of the pad 8 is formed near the air outflow end 7 (FIG. 2) by setting the downwardly protruding height p3 of the pad 8 from the ABS 4 low. Even if it does, the floating amount of the pad 8 does not reach an excessive floating amount. Therefore, it is not necessary to increase the pitch. Further, since the height p3 is set low, the magnitude of the rotational moment based on the attraction force and frictional force between the pad 8 and the magnetic disk 10 can be reduced, and the occurrence of the attraction failure due to the inclination of the magnetic head slider can be suppressed.

[0023]

As described in detail in the above embodiments, the flying magnetic head slider of the present invention has the following effects. That is, even if the height of the pad of the slider protruding from the ABS is reduced, the magnetic disk and the magnetic head slider can be prevented from being attracted when the magnetic disk starts rotating or stops. As a result, it is possible to prevent the magnetic disk and the magnetic head slider from being damaged due to the suction during the CSS operation, and to secure the reliability of the magnetic disk device.

Further, the pad formation position can be moved to a position closer to the air outflow end side as compared with the conventional one. Therefore, it is possible to suppress the magnetic head and the magnetic disk from being attracted by the inclination of the magnetic head slider about the pad. Also, since the height of the pad of the magnetic head slider protruding from the ABS can be reduced, the spacing loss between the magnetic disk and the magnetic head can be reduced, and a magnetic disk device with a high recording density can be realized. Furthermore, A
By relaxing the restrictions on the BS flying pitch and pad formation position, a stable low flying height can be achieved, and the flying height and flying attitude depend on atmospheric pressure, rotation speed, seek operation, and skew angle. Since the design of the ABS with reduced noise is facilitated, the industrial effect is great.

[Brief description of the drawings]

FIG. 1A is a bottom view of a magnetic head slider according to an embodiment of the present invention. FIG. 1B shows the relationship between the magnetic head slider and the magnetic disk at the time of startup or rotation stop, and Ib-I of FIG.
Side sectional view at line b

FIG. 2 is a side sectional view showing a flying state of the magnetic head slider of the embodiment caused by rotation of the magnetic disk.

FIG. 3 is an enlarged side sectional view of a pad forming portion of the magnetic head slider according to the embodiment of the present invention;

FIG. 4 is a side sectional view of a conventional magnetic head slider.

FIG. 5 is a side sectional view showing a state in which a conventional magnetic head slider is tilted when starting a magnetic disk.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 magnetic head slider 2 arrow indicating rotation direction 3 air inflow side ABS 4 air outflow side ABS 5 magnetic head element 6 air inflow end 7 air outflow end 8 air outflow end side pad 9 air inflow end side pad 10 magnetic disk 11 recess

Claims (3)

[Claims] When a magnetic disk as an information recording medium is rotated, an air bearing surface (hereinafter referred to as ABS) facing the magnetic disk to record or reproduce information at a predetermined position on the magnetic disk surface. The magnetic head attached to the magnetic disk is moved in the radial direction of the magnetic disk by floating with the flowing air. When the magnetic disk is stopped, the pad that contacts the magnetic disk projects downward from the ABS by a predetermined height. A magnetic head slider provided so that a concave portion is formed on an outer periphery of the pad in the ABS. 2. The magnetic head slider according to claim 1, wherein the pad is provided near the air outflow end side ABS. 3. The magnetic head slider according to claim 1, wherein a floating amount of the pad from the magnetic disk surface during the floating movement is larger than a floating amount of the magnetic head.