JPH043030B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a slider for a magnetic head of a magnetic disk device, and in particular to a magnetic slider that has a small flying height of the slider and is suitable for use in a hard disk device with a high magnetic recording density. Regarding head sliders.

[Background of the invention]

A magnetic disk storage device writes and reads information by floating a magnetic head mounted on a slider across a small gap over the surface of a magnetic recording disk. A slider carrying this magnetic head is supported against the disk surface so as to allow pitching and rolling movements. Further, this slider is provided with a plurality of rails having the same width and extending in the longitudinal direction with gaps in the lateral direction on the surface facing the disk surface. As a result, when the disk rotates, air is drawn between the rail and the disk, generating pressure, pushing the slider away from the disk surface, and creating a flying height g.

The conventional slider rail for this type of magnetic head is as described in Japanese Patent Publication No. 57-569, for example.
It consisted of a tapered part and a flat part. However, no consideration was given to the taper length and taper angle.

Although dust is removed as much as possible from the inside of a magnetic disk device to create a clean environment during assembly, it is difficult to completely remove dust. For this reason, in the conventional slider, these dust particles adhere to the tapered portion and the flying height g suddenly decreases, thereby sometimes coming into contact with the disk. This rapid reduction in the flying height g due to the attached dust is a fatal drawback, especially in high-density magnetic disks with a small flying height g.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a slider for a magnetic head in which the flying height is minimized even if dust adheres to the slider taper portion.

[Summary of the invention]

It has become clear that when dust adheres to the slider taper, the flying height of the slider decreases rapidly, which is a major cause of contact with the disk. Furthermore, even if the same height of dust adheres, the amount of reduction in flying height differs depending on the slider taper length and taper angle. The present invention is characterized by a slider having a taper length and a taper angle that minimize the amount of reduction in flying height due to attached dust by changing the taper length and taper angle.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

FIG. 1 is a plan view illustrating how the disk, magnetic head and slider are installed, and FIG. 2 is a side view thereof. A magnetic head slider 2 on which a magnetic head 1 is mounted is supported by a gimbal 3 for allowing pitching and rolling movements of the slider 2, and a load arm 5 for pressing the slider 2 against a disk 4 rotating in the direction of the arrow. Slider 2
In this example, two rails 6 are provided on the surface facing the disk 4. When the disk 4 rotates, air is drawn between the rail 6 and the disk 4, pressure is generated, and the slider 2 is pushed away from the surface of the disk 4, producing a flying height g. FIG. 3 is a diagram of the slider 2 viewed from the disk 4 side. The disk 4 is rotating in the direction of the arrow, and the magnetic head 1 is provided on the downstream side and the taper 7 is provided on the inflow side. FIG. 4 is a side view of the slider 3.

The target magnetic disk device of this embodiment is a large magnetic disk device with a disk outer diameter of 356 mm and a rotation speed of 3600 rpm.

Now, we will consider how to set the taper length l _T and taper angle θ _T. Assuming that dust has adhered to the tapered part of the slider shown in Figure 4, as an evaluation index for the amount of reduction in flying height due to attached dust, the flying height when dust is attached is made dimensionless by the flying height before dust is attached. The largest value is expressed as 100.
Taper length (of the slider at a certain pressing force W)
Figure 5 shows the results obtained by changing l _T and taper angle θ _T.

It can be seen from FIG. 5 that the amount of reduction in flying height due to attached dust varies depending on the combination of taper length and taper angle. Also, from Figure 5, the taper length l _T
By setting _the ratio _{(l T / l} In this example, the gimbal pressing force W was kept constant, and the taper length and taper angle with the smallest reduction in flying height due to attached dust were determined. However, the taper length and taper angle that cause the smallest amount of flying reduction due to attached dust vary depending on the pressing force. Currently, the pressing force W of light load sliders is used in the range of 5.5 to 1.5 gf.
Therefore, the taper length l _{T and the taper angle θ T with} the smallest reduction in flying height due to attached dust were determined in the same manner when the pressing force W was in the range of 5.5 to 15 gt. The results are shown in FIG.

From FIG. 6, it can be seen how the combination of the taper length l _T and the taper angle θ _T that causes the smallest amount of flying reduction due to attached dust changes depending on the pressing load W.

Equations (3) and (4) are expressions of this relationship.

θ _{T =} −4.4 ₍ l _{T / l} The range of the constant in equation (4) is the slider pressing force W
This shows that even if it is taken into consideration that the taper length l _T and the taper angle θ _T at which the flying drop is the smallest change due to the difference in the position of , the values fall within the above range.

As mentioned above, the slider for a magnetic head, which is the object of the present invention, has a plurality of rails of the same width extending in the longitudinal direction at intervals in the lateral direction on the opposing surfaces of the disk surface, This draws air between the rail and the disk when the disk rotates, increasing the pressure and causing the disk to float above the surface.
Therefore, the essential principle of levitation is the same even if the disk diameter or rotational speed is different, and equations (3) and (4) hold true even if the disk diameter or rotational speed is different.

From the above, the taper length l _T and taper angle θ _T are
If equations (3) and (4) are selected to satisfy both equations, the amount of reduction in flying height due to attached dust can be minimized under the intended pressing force.

Although dust is removed as much as possible from the inside of a magnetic disk device to create a clean environment during assembly, it is nevertheless difficult to completely remove dust. For this reason, dust remaining inside the magnetic disk device may adhere to the slider, resulting in a sudden drop in flying height and contact with the disk. This phenomenon becomes a bigger problem as the flying height of the magnetic head becomes smaller.

Therefore, the present invention is most promising for high conductivity magnetic disk devices in which the flying height of the magnetic head is small.

〔Effect of the invention〕

According to the present invention, the reduction in the flying height of the slider due to attached dust can be reduced, so the frequency of contact between the disk and the slider can be reduced, and the reliability of the apparatus can be improved.

[Brief explanation of drawings]

FIG. 1 is a diagram illustrating the state of the device of the magnetic head slider and disk of the present invention, FIG. 2 is a side view of FIG. 1, and FIG. 3 is a disk of the magnetic head slider in FIGS. 1 and 2. 4 is a side view of the magnetic head slider in FIGS. 1 and 2, and FIGS. 5 and 6 show the taper length, taper angle, and amount of flying reduction due to attached dust. FIG. 1...Magnetic head, 2...Slider for magnetic head, 3...Gimbal, 4...Magnetic disk, 5...
...Load arm, 6...Rail, 7...Taper.

Claims (1)

[Scope of Claims] 1. In a slider for a magnetic head of a magnetic disk device equipped with a floating rail having a tapered portion and a flat portion, the floating rail has a rail length of l _x ,
When the pressing force of the slider is W (gf), the taper length of the inflow part is l _T , and the taper angle is θ _T (°), the following (1),
A slider for a magnetic head, characterized in that it is constructed so as to satisfy equation (2) at the same time. _−4.4 (l _T / l _X ) + 1.14 _< θ _T < −4.4 (l _{T / l} (8.4−0.37W) (l _T / l _X ) ……(2)