JPH0555954B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a floating head mechanism that stably floats the surface of a magnetic recording medium of a magnetic disk device using a minute air film.

[Conventional technology]

As is well known, a magnetic head for a magnetic disk device uses a floating head slider that floats above the surface of a recording medium based on the principle of a dynamic pressure gas bearing.
The smaller the floating amount of the floating head slider is, the better, in order to increase the capacity and density of the magnetic disk device, and currently, a floating amount in the submicron range of about 0.3 μm has been put into practical use. The magnetic head currently in practical use is a positive pressure type floating head slider that generates only a positive load capacity as the recording medium travels. In particular, in order to maintain good slider followability against the vibrations of the recording medium, an extremely light-load slider of an elongated tapered flat type in which the slider air film has high rigidity and large damping has been put into practical use. However, in order to further reduce the floating amount with this type of floating head slider, it is necessary to increase the load (=load capacity) applied to the slider, but this poses a major problem for the reliability of the slider recording medium interface. becomes.

For this reason, there has recently been an active development of so-called negative pressure floating head sliders in which a reverse step surface or the like is formed within the slider bearing surface and negative pressure is generated there through air film lubrication. In this type of slider, the load to be applied from the outside is partially covered by the suction force due to the negative pressure generated within the slider bearing surface, so an extremely highly rigid air film can be effectively achieved with a light load. be.

Furthermore, the so-called contact start/stop method (hereinafter abbreviated as the CSS method) is used to start and stop the floating head slider and the recording medium, in which the slider starts and stops while it is in contact with the recording medium. . This has been put into practical use because the load on the slider has become extremely small.

[Problem that the invention seeks to solve]

This CSS method has the advantage of reducing costs because the structure of the floating head mechanism is simple, but on the other hand, it has the advantage of reducing tribological reliability in the mechanical interface between the slider and the recording medium. is becoming a big problem.
That is, in this method, the slider and the recording medium run while contacting each other until they reach a complete air film lubrication state, so a boundary lubrication region exists.
In this region, the slider and the recording medium exhibit extremely complicated phenomena such as stick slip phenomenon.
Then, tribological interference occurs between the medium protective film or lubricant formed on the recording medium and the slider, causing a head crush phenomenon in which the medium is scratched.

With current magnetic disk devices, approximately 20,000 times
CSS properties must be reliably implemented, which has become extremely difficult. In particular, recent floating head sliders are made of superhard ceramics (such as Al ₂ O ₃ -TiC).
It is extremely difficult to match CCS characteristics with metal thin film media, which are expected to be the next generation recording media.

Furthermore, this CSS method has another major problem as the floating amount of the slider becomes smaller. That is, it is a problem of adhesion between the slider and the recording medium. Due to the increase in the capacity and density of magnetic disk devices, the flying height of the slider is now in the submicron range of about 0.3 μm, but for this reason, the slider surface of current floating head sliders and the medium surface of thin film media have become mirror-like. Processed.

Therefore, if the magnetic disk device is left in a state where the slider and the recording medium are in contact with each other, a phenomenon occurs in which the slider and the recording medium are attracted to each other. Since both surfaces are extremely flat, their suction force is so great that either the recording medium will not rotate, or if the recording medium is forced to rotate, problems such as damage to the gimbal spring that supports the floating head slider will occur.

The purpose of the present invention is to eliminate the drawbacks of the floating head mechanism that employs the above CSS method, to start and stop without performing CSS with the recording medium, and to provide a highly reliable floating head mechanism that provides good recording and playback characteristics. It is about providing.

[Means for solving problems]

The floating head mechanism of the present invention includes a pair of thin plate beam structure load beams whose rear ends are fixed and provided in parallel, piezoelectric elements bonded to the front and back surfaces of each of the pair of load beams, and a pair of thin plate beams arranged in parallel. The present invention includes a binder that connects the tips of the structural load beams to each other to form an integral structure, and a negative pressure floating head slider that is attached to the tips of the pair of thin plate structural load beams via a tongue-shaped gimbal spring. configured.

〔Example〕

The present invention will be explained in detail below using the drawings.

FIG. 1 shows a floating head mechanism according to the present invention. In the figure, 1 is a load beam with a thin plate beam structure, 2 is a tongue-shaped gimbal spring, and 3 is a load beam with a thin plate beam structure.
is a floating head slider using negative pressure, 4 is a binder,
5 is a piezoelectric element bonded to the front and back sides of a thin plate beam structure load beam, and 6 is a magnetic recording medium.

According to this mechanism, as the magnetic recording medium rotates, the negative pressure floating head is brought closer to the surface of the recording medium to generate an air bearing effect, and when the recording medium stops, the negative pressure floating head is moved away from the surface of the recording medium, causing the magnetic recording medium to move toward the surface of the recording medium. It is possible to hold the floating head without contact with the head. FIG. 2 is a diagram showing the operating principle of a negative pressure floating head that self-loads when the mechanism is activated. The operating mechanism will be explained in detail using this figure and FIG. 1.

As the recording medium rotates, a voltage is applied to a pair of piezoelectric elements 5 bonded to the thin plate beam structure load beam 1 to deform the piezoelectric elements so that the negative pressure floating head slider 3 approaches the surface of the magnetic recording medium 6. let The thin plate beam structure load beam 1 to which the piezoelectric element 5 is bonded is effectively a pair of bimorph structures, the tips of which are joined by a binder 4 as shown in FIG. Therefore, the assembly consisting of the negative pressure floating head slider 3 and the tongue-shaped gimbal spring 2 attached to the binder 4 is displaced parallel to the recording medium surface 6. Therefore, when the negative pressure floating head slider 3 accesses the recording medium surface 6, the slider can be moved while remaining parallel to the surface of the recording medium 6. In other words, the negative pressure-utilizing floating head slider 3 does not access the surface of the recording medium 6 at an oblique angle with respect to the surface of the recording medium 6, and exhibits extremely stable behavior.

After being displaced from the resting state, the relative gap between the surface of the recording medium 6 and the negative pressure floating head slider 3 is h. Figure 2 shows the relationship between the relative gap h between the negative pressure floating head slider 3 and the surface of the recording medium 6, and the generated levitation force and suction force, determined by numerical calculation. gap
It can be seen that at ha, the suction force becomes extremely larger than the buoyancy force. Therefore, in this state, the buoyant head is hydrodynamically loaded toward the surface of the recording medium 6 in a self-aligned manner, and is stably floating in the levitation gap in the submicron region, the gap hm shown in the figure. Become.

Furthermore, when the recording medium 6 stops, the voltage applied to the pair of piezoelectric elements 5 is removed before the recording medium 6 completely stops, and the voltage is applied in the opposite direction, that is, in a direction in which the slider moves away from the surface of the recording medium. By doing so, it is possible to return the negative pressure-utilizing floating head 3 to the initial stationary state before the rotation of the recording medium surface stops. When the recording medium 6 travels at low speed, the suction force generated on the slider bearing surface is also small, making it easy to realize the above operation. For these reasons, in the floating head mechanism of the present invention, the self-loading mechanism of the negative pressure floating head is combined with the actuator mechanism formed by a pair of bimorph piezoelectric elements formed on the thin plate beam structure load beam. , it becomes possible to start and stop floating heads without using the conventional CSS method.

Note that any modification may be made without departing from the spirit of the present invention; for example, the shape of the floating head slider using negative pressure, the shape of the support spring, etc. may be suitable for each case, and the above embodiments may be used. It goes without saying that the examples do not limit the scope of the invention in any way.

〔Effect of the invention〕

As explained in detail above, the floating head mechanism of the present invention is suitable for large-capacity, high-density magnetic disk drives.
It has the effect of being able to start, stop, record and play without using the CSS method, therefore,
A highly reliable floating head mechanism can be realized.

[Brief explanation of the drawing]

FIG. 1 is a side view of one embodiment of the floating head mechanism of the present invention, and FIG. 2 is a diagram showing the operating principle of the self-loading mechanism of the floating head using negative pressure according to the embodiment shown in FIG. DESCRIPTION OF SYMBOLS 1... Thin plate beam structure load beam, 2... Tongue-shaped gimbal spring, 3... Floating head slider using negative pressure, 4... Binder, 5... Piezoelectric element, 6... Magnetic recording medium.

Claims (1)

[Claims] 1. A pair of thin plate beam structure load beams whose rear ends are fixed and are provided in parallel, and piezoelectric elements bonded to the front and back surfaces of each of the pair of load beams,
a binder that connects the tip ends of the pair of thin plate beam structure load beams to each other to form an integral structure; and a negative pressure-utilizing floating head attached to the tip ends of the pair of thin plate beam structure load beams via a tongue-shaped gimbal spring. A floating head mechanism comprising a slider.