JPS5821329B2 - floating head slider - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a contact start/stop type magnetic rad slider used in magnetic disk drives.

Conventionally, magnetic disk drives have used floating RAD sliders that float while maintaining a small gap between the recording media using the dynamic pressure generated by the running of the recording media.
A recording/reproducing magnetic head consisting of a core and a coil is formed on this floating RAD slider.

The magnetic head can obtain a higher recording density and a larger output the closer it is to the recording medium surface, so it is usually formed at the minimum gap position on the slider surface facing the recording medium of a floating RAD slider. Common.

The minimum gap position of the slider surface is determined by the shape of the slider surface, the load force, and the position of the point of application of the load force.

1 For example, as shown in FIG.
In a tapered flat monolithic slider in which the slider surface 2 is formed flat, and the tapered surface 3 having a taper height δt is formed at the air inflow side end 2A of the slider surface 2, the air outflow end 12B and the arrow mark Since the gap G between the magnetic recording medium 4 traveling in the direction A forms the minimum gap, a gap 7 of the magnetic herad core 5 is formed at the outflow end 2B.

In addition, 6 in the figure is a winding wound around the magnetic head core 5.

In addition, as shown in Fig. 2, in a cylindrical floating Rad slider in which the slider surface 2 is formed as a cylindrical surface, the position of the minimum gap G changes depending on the crown height δC1 load force and the position where the load force is applied. Therefore, the magnetic helical core 5 is formed at the minimum clearance position of the cylindrical slider at the time of design.

By the way, in order to make the floating head slider float above the magnetic recording medium with a minute gap of about 0.2 μm, it is necessary to finish the surface of the magnetic recording medium to a perfect mirror finish.

However, when using a floating RAD slider in a contact start-stop method, if the mirror-like magnetic disk surface and the slider surface of the tapered flat slider are left in close contact for a long time, the floating RAD slider will be attracted to the magnetic disk surface. The phenomenon of being left behind occurs.

If you start a contact start while the disk is stuck in this way, you will not only scratch the disk surface and destroy the recorded information, but also destroy the magnetic head support system, so stop the magnetic disk. Sometimes it is desirable to keep the floating head slider separate from the magnetic disk surface or to use a cylindrical slider with a small contact area in order to significantly reduce the attraction force.

However, the method of separating the floating RAD slider from the magnetic disk surface requires a certain mechanism, the structure is complicated, and the method of separating the floating RAD slider from the magnetic disk surface without damaging the magnetic disk surface and the slider surface. It is difficult to control the landing.

In addition, in the method using a cylindrical surface slider, as mentioned above, the minimum gap position is not on the air outflow end side but is usually near the center of the slider surface.
As seen in the magnetic head for type 330 devices, a so-called embedded head method is used in which a slit is provided in the center of the slider and a magnetic rad core is inserted therein.

However, even in this embedded head method, slit formation is difficult to machine, so it has to rely on mold processing, which poses problems in terms of accuracy.11) As seen in the core for the IBM 3330 head. The main magnetic path of the magnetic rad core, which is formed separately, and the magnetic path of the winding section must be connected to each other, which makes it impossible to obtain a good magnetic path, and furthermore, the magnetic resistance increases and the efficiency of the magnetic head decreases. This had the disadvantage that it was only about 60% as effective as a normal monolithic head.

. On the other hand, if we assume a monolithic type with a cylindrical core and the gap position of the magnetic head core is made to be the same as that of the conventional tapered flat slider as shown in Figure 1, the gap position will be Practical as it does not match the minimum gap position on the slider surface.

It cannot be offered to

Furthermore, when the gap 7 of the magnetic helad core 5 is formed in the center of the magnetic head slider 1 as shown in FIG.
The disadvantage is that the magnetic path length becomes longer, the efficiency of the magnetic head is greatly reduced, and the strength is also significantly reduced.

Furthermore, as shown in Fig. 4, if the gap 7 is positioned at the center of the core while keeping the magnetic path length of the core short, there is a drawback that winding the coil 6 becomes extremely difficult. .

The present invention has been made to eliminate the above-mentioned drawbacks, and has an extremely simple structure in which the slider surface is made into an arcuate surface and a tapered surface is provided on the side of the air inflow end, thereby preventing adsorption to the magnetic disk surface. ; To provide a magnetic rad slider in which the magnetic head efficiency is improved by stopping or reducing the gap position and positioning the gap at the minimum flying position of the slider.

Hereinafter, the present invention will be described in detail with reference to the drawings.

Fig. 5 shows an embodiment of the magnetic herad slider according to the present invention, in which a is a front view, b is a bottom view, and c is a side view.

In addition, the same parts as in FIGS. 1 to 4 are indicated by the same reference numerals.

In the same figure, the slider 1 surface 2 of the floating hent slider 1
is the circular arc surface 20 of crown height δC and the air inflow side end 2
The tapered surface 3 is formed at A and has a taper height δt.

A magnetic Rad core 5 is provided at the air outflow end 2B of the floating Rad slider 1, and a gap 1 of the core 5 is positioned at the minimum gap G between the air outflow end 2B and the magnetic recording medium 4. It is formed like this.

The magnetic helad slider 1 is made of a magnetic material such as ferrite, and the magnetic helad core 5 is a so-called monolithic head formed by cutting out the slider material.

Further, the crown height δC is limited to a range of 0.1 μm to 0.4 μm in order to avoid adhesion to the surface of the magnetic recording medium and at the same time to ensure that the pressure generated on the tapered surface 3 is sufficiently high.

In this way, the floating head slider of the present invention has slider surface 2.
The arcuate surface 20 is formed at the air inflow side end 2Aζ
Since this tapered surface 3 is formed, the pressure at the air inflow side end 2A is smaller than that of the conventional slider described above, and a stable floating posture can be obtained with the minimum gap G near the air outflow end 2B. A monolithic magnetic head with good magnetic head efficiency and easy winding work of the coil 6 can be realized.

Here, functional differences between the configurations of the present invention and the conventional devices shown in FIGS. 1 to 4 will be explained.

First, as seen in the tapered flat slider shown in Figure 1, the tapered surface, which is one of the basic shapes of the floating rad slider, generates a stable floating edge only when it is formed at the inlet end of the flat slider. In particular, as mentioned above, it is well known that a plane slider used in a contact start/stop method generates a flying edge at the time of startup.

On the other hand, in the conventional cylindrical slider shown in FIG. 2, the crown height δC is generally designed to a value that maximizes the flying edge.

That is, if the crown height δC is too small or too large, sufficient floating edges will not be generated, and there is an optimum value at which the floating edges are maximum.

If the minimum flying height is ho, this optimal value is 2 to 2 of ho.
It is about 10 times as large.

This characteristic is well known in the field and is therefore usually crown height δC beam.

It is designed to be about four times as large as the

This is also because by designing to this value, the influence of machining errors in the crown height δC on the flying characteristics can be minimized.

In this case, there is no need to form a tapered surface at the inflow end, and even if it is formed, it has almost no effect on the flying characteristics, so there have been no examples of forming a tapered surface on a cylindrical slider. Ta.

However, in spite of these circumstances, the present invention not only avoids adhesion by combining a tapered surface and an arcuate surface, but also allows the minimum gap position of the slider surface to be moved to the rear of the slider surface in the cylindrical surface slider. We succeeded in bringing it closer to the edge.

In this case, the purpose of the arcuate surface 20 is not to generate levitation force but to avoid adhesion to the mirror-finished magnetic recording medium surface, and the purpose of the tapered surface 3 is to prevent the slider surface 2 formed on the arcuate surface 20 from attracting the surface of the magnetic recording medium. The purpose is to bring the minimum gap position closer to the rear end of the slider surface 2.

That is, according to experiments conducted by the present inventor, it has been confirmed that when the flying height of the floating RAD slider is reduced to about 0.2 μm, the effects of the tapered surface 3 and the arcuate surface 20 are significant.

Specifically, the flying height of the RAD slider is set to about 0.2 μm.

Then, the surface roughness of the medium surface is preferably 0.02 μm or less in terms of center line average roughness Ra.

In this case, as described above, if a tapered flat slider is used in the contact start/stop method, there is an extremely high risk that an adsorption phenomenon will occur.

To avoid this, the crown height δ of the arc surface 20
C may be about 0.1 μm.

On the other hand, in this case, the optimal value of the crown height (δc
/ho=4), the floating clearance at the inflow end 2A is 1μ.
Since the gap becomes as large as approximately m, even if a tapered surface is provided here, the effect of the tapered surface is lost, and it becomes impossible to bring the minimum gap position closer to the rear end of the slider surface.

Therefore, in order to exhibit the effect of this tapered surface, δC should be set to 0.1 μm in the region around the flying height of 0.2 μm.
It is said that it is desirable to set it in the range of ~0.4 μm.

FIG. 6 shows another embodiment of the present invention, in which a is a front view of the head, b is a bottom view, and C is a side view.

In this embodiment, the air outlet end side 2 of the slider material is
All other configurations are the same as the embodiment shown in FIG. 5, except that B is grooved for winding processing and the magnetic rad core 5 is embedded in this groove.

Even in this configuration, the minimum gap G between the two air inflow ends and the magnetic recording medium 4 is obtained in the vicinity of the outflow end 2B due to the action of the tapered surfaces 3 of the two air inflow ends, so that the same effect as in the above embodiment can be obtained. In addition, it is possible to realize an embedded type magnetic head with sufficient strength.

As explained above, according to the floating RAD slider according to the present invention, the slider surface is formed into an arcuate surface, and a tapered surface is formed at the end on the air inflow side, so that adsorption to the magnetic disk surface is prevented or significantly reduced. Moreover, the tapered surface provides a flying posture in which the minimum gap is located near the air outflow end, which improves the efficiency of the magnetic head and makes it easier to wind the coil. It becomes possible to form

・Brief description of the drawings Figures 1 and 2 are front views showing an example of a conventional floating Radoslider, and Figures 3 and 4 are for explaining the drawbacks of the conventional floating Radoslider. a is a front view, b is a bottom view, FIG. 5 shows an embodiment of the floating Radoslider according to the present invention, a is a front view, b is a bottom view,
C is a side view, FIG. 6 shows another embodiment of the present invention, a is a front view, b is a bottom view, and C is a side view.

1...Floating RAD slider, 2...Slider surface, 2A...Air inflow side end, 2B...
...Air outflow end, 3...Tapered surface, 4...
... Magnetic recording medium, 5 ... Magnetic helad core, 6 ... Coil, 20 ... Arc surface.

Claims (1)

[Claims] 1. In a floating RAD slider floating above the surface of a magnetic recording medium, the slider surface is formed into an arcuate surface, and
1. A floating rad slider, characterized in that a tapered surface is formed at the air inflow side end, and the minimum gap between the slider surface and the magnetic recording medium surface is located near the air outflow end.