JPH09265738A - Head supporting mechanism and information recorder - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize an information recorder of a high recording density and more particularly high track density and a head supporting mechanism suitable for the same and to reduce the cost of an information recording and reproducing device by inexpensively producing a suspension. SOLUTION: Piezoelectric actuators 7 are disposed on both sides of the suspension 3 and are discretely operated to twist the suspension 3. The displacement at the front end portion 8 of the piezoelectric actuators 7 generated to twist the suspension 3 is reduced and the micro-positioning in the track width direction of a head element 1 is executed. The suspension 3 arranged with the piezoelectric actuators 7 on both sides is batch-produced by a batch process.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information recording device such as a magnetic disk device and a head support mechanism applied to those devices. In particular, the present invention relates to a structure of a head support mechanism that is most suitable for realizing a high recording density of a magnetic disk device.

[0002]

2. Description of the Related Art At present, a magnetic head applied to a magnetic disk device is formed in a portion generally called a slider, and the magnetic disk device utilizes servo information recorded on the magnetic disk to move the magnetic head onto the slider. Control is performed to position the magnetic head formed on the magnetic disk at an arbitrary position on the magnetic disk. Some of the magnetic heads used as described above have been downsized and are formed of a thin film. There are roughly two types of magnetic heads formed of thin films, and there are a magnetic head composed of a recording / reproducing element and a composite magnetic head in which a recording element and a reproducing element are formed independently.
These thin film magnetic heads are usually formed on a slider body that serves as a base material and is held by a head support mechanism.

A slider on which a magnetic head is mounted is fixed to an actuator provided in a magnetic disk device via a head support mechanism, and is positioned at an arbitrary position on the magnetic disk by controlling the actuator. Therefore, in order to increase the recording density in the future, various proposals have been made regarding a highly accurate positioning technique of the magnetic head.
As an example of conventional technology, Journal of Japan Applied Magnetics Vol. 18, 4
No. (1994), page 867, FIG. There is one shown in 8. As shown in FIG. 5, a structure in which a head support mechanism (suspension 31) to which a head slider (not shown) is fixed swings with respect to a coarse actuator (not shown) of a magnetic disk device is described therein. ing. In this paper, in order to increase the recording density, attention is paid to the improvement of the track density of the magnetic disk device, and in FIG. 5, it is described as a coarse movement actuator of the head support mechanism (suspension 31) to which the head slider is fixed. A pair of planar type piezo elements 19 are installed with the center of rotation of the head mount block (mounting section 61), which is a fixed section, being incorporated, and the head supporting mechanism (suspension 31) is slightly shaken by making them differential. The head slider and the head element, which are fixed to the tip of the head support mechanism, can be moved minutely. Planer
The type piezo element 19 cannot generate a large displacement, but by slightly rotating the suspension 31 about the central hinge 20, the displacement of the planar type piezo element 19 is enlarged eight times at the head element position. There is. In this paper, the positioning accuracy of the head element in the track width direction is improved by interlocking the positioning of the coarse actuator and the minute positioning of the head slider and head element by the slight swing of the head support mechanism. It is described that the track density can be increased. Further, it can be easily inferred from FIG. 5 that this positioning mechanism is assembled after the suspension 31, the mount portion 61, and the planar type piezoelectric element 19 are separately formed.

Further, Journal of Japan Applied Magnetics Vol. 18, No. 4 (1994), 866-867, FIG. In addition to the above, 7 and 11 are provided with other means for finely positioning the head elements in order to improve the positioning accuracy of the head elements in the track width direction and increase the track density.
The positioning and the minute positioning mechanism of the head element are described.

As means for increasing the recording density of the information recording apparatus, in addition to the high-accuracy positioning of the magnetic head, the flying height of the magnetic head is reduced to improve the recording density in the circumferential direction of the magnetic disk. Is also extremely important. As one of means for achieving a low flying height of a magnetic head, a method of reducing the surface roughness of a magnetic disk is generally taken.

[0006]

In any of the above-described conventional examples, the displacement of the head element transmits the displacement of the actuator as it is or in a magnified manner in any structure, and the positioning accuracy of the head element depends on the actuator. There is a problem that the accuracy becomes lower than that, and sufficient accuracy cannot be obtained.

Although not described in detail, the head micropositioning consisting of the piezo element and the head support mechanism main body or the guide arm can be taken from the structure of the actuator and the head support mechanism described in the drawings and the description. It is speculated that the mechanism is made by assembling these parts. However, in the case of a magnetic disk device,
As the recording density becomes higher, the head support mechanism becomes smaller, which makes it difficult to manufacture a structure by assembling.

Further, the piezo element generally has a small generated displacement / element size, and even in the known example described with reference to the above-mentioned drawings, the generated displacement of the piezo element is magnified eight times. A piezo element having a length of about 5 mm is required to generate a displacement of 6 μm, and if the displacement generated in the horizontal direction with respect to the recording medium surface is directly used for the displacement of the magnetic head, the actuator size becomes large. Points also occur. There is also a problem in reducing the surface roughness of the magnetic disk. In the magnetic disk device, the magnetic disk and the slider are in contact with each other when the device is stopped, and the magnetic disk device generally floats due to the generation of an air flow accompanying the rotation of the magnetic disk. However, when the surface roughness of the magnetic disk is reduced, the magnetic disk and the slider are attracted or adhered to each other, and the torque at the start of rotation of the magnetic disk increases. However, the publicly known example does not mention any means for solving this problem.

Therefore, an object of the present invention is to provide sufficient positioning accuracy of the head element and prevent the magnetic disk and slider from being attracted or sticking to each other by reducing the surface roughness of the magnetic disk. It is to realize the mechanism. Furthermore, it is to realize an information recording apparatus having a high recording density by applying such a head supporting mechanism.

[0010]

With respect to the problem that it is necessary to increase the positioning accuracy, an actuator that can make a large stroke is used as a drive source, and a portion that holds a head element is driven by a displacement reduction mechanism. Specifically, the actuators are arranged on both sides of the head support mechanism, and both of them are differentially operated, or one of them is operated to twist the head support mechanism. The head element is placed near the line connecting the center axis of the torsion and the point of action of the actuator, passing through the center axis of the torsion, and the distance between the actuator and the center axis of the torsion is set to the center axis of the torsion and the head element. Larger than the distance.

Regarding the problem that it becomes difficult to manufacture a structure by assembling, a means for minutely positioning the elements at the time of manufacturing the head support mechanism is collectively manufactured. Specifically, an actuator that twists the head support mechanism described above.
The actuators are parallel plate type electrostatic actuators and hydromorphic bimorph type actuators that can be manufactured collectively by a batch process. The head support mechanism is manufactured by a batch process such as micromachining based on semiconductor manufacturing technology, in which case the actuator is also manufactured collectively.

Regarding the problem that the actuator size becomes large, as described in the means for solving the above two problems, the structure of the head support mechanism is used as it is as a part of the drive source, and at the same time the head support mechanism is The twisting motion is converted into the displacement of the head element.

Regarding the problem that the magnetic disk and the slider are attracted or adhered to each other by reducing the surface roughness of the magnetic disk, and the torque at the start of rotation of the magnetic disk becomes large, immediately before the start of rotation of the magnetic disk. , The head support mechanism is repeatedly twisted to separate the slider from the magnetic disk.

The head element is disposed near the line connecting the central axis of the torsion and the point of action of the actuator through the central axis of the torsion, and the distance between the actuator and the central axis of the torsion is the central axis of the torsion. Since the distance from the head element is larger than that of the head element, the head element can be operated with higher accuracy than the operation accuracy of the actuator. Further, by using this actuator in a fine movement actuator of a two-stage actuator such as an optical disk device, a magnetic disk device having a high recording density can be realized.

Further, since the head supporting mechanism is not manufactured by assembling a plurality of conventional parts, but is manufactured collectively by a batch process such as micromachining based on semiconductor manufacturing technology, an actuator is used. Even if the structure attached to the head support mechanism becomes complicated, the head support mechanism can be easily realized. Similarly, even if the head support mechanism is downsized, it can be easily manufactured.

Further, the head support mechanism realized as described above does not exceed its original size because of its structure.

In addition, the head supporting mechanism realized as described above is repeatedly twisted immediately before the start of rotation of the magnetic disk,
By peeling off the slider from the magnetic disk, adhesion and adsorption are released, the coefficient of friction between the slider and the magnetic disk is reduced, and the torque at the start of rotation of the magnetic disk is also reduced.

[0018]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described below with reference to the drawings.

FIG. 1 is a perspective view of a head support mechanism showing an embodiment of the present invention, and FIG. 2 is an operation explanatory view of FIG. 1 viewed from the direction A. The head support mechanism has a head element 1 mounted thereon, and a slider 2 flying or sliding on a rotating or running recording medium, a suspension 3 supporting the slider 2, and a signal for electrically connecting the head element 1 and the recording / reproducing circuit of the information recording apparatus. It is composed of a system (not shown), and a part or the whole thereof is integrally formed. The signal system is composed of a lead wire or a printed circuit arranged directly or indirectly on the suspension 3. In the suspension 3, the slider 2 can follow the fluctuation in the vertical direction (vertical direction in the drawing) on the recording medium and in the horizontal direction (horizontal direction in the drawing) on the recording medium.
A gimbal portion 4 (shaded area in the drawing) which holds the slider 2 in such a manner that the slider 2 can be precisely positioned on the slider, and a load arm portion which applies a downward load in the drawing to the slider 2 via the gimbal portion 4. 5, a mount part 6 for connecting the load arm part 5 to the coarse movement actuator of the information recording apparatus, and these parts are integrally or individually formed. Bimorph-type piezoelectric actuators 7 whose front ends move in the vertical direction in the figure are arranged on both sides of the load arm portion 5.

The piezoelectric actuators 7 on both sides of the load arm portion 5 are controlled so as to be differential. That is, the tip of the piezoelectric actuator 7a on the left side of the figure moves downward in the figure, and at the same time the tip of the piezoelectric actuator 7b on the right side of the figure moves upward in the figure. The piezoelectric actuators 7a and 7b thus operated operate independently. Then, the tip portion 8 of the piezoelectric actuator 7 tilts upward and upward. If a step is provided between the tip portion 8 of the piezoelectric actuator 7 and the holding portion 9 of the gimbal portion 4, the gimbal portion 4
The holding portion 9 tilts upward and to the right in parallel with the tip portion 8 of the piezoelectric actuator 7, and simultaneously moves to the right side, and the gimbal portion 4, the slider 2, and the head element 1 also move to the right side in a continuous manner. The rigidity of the gimbal portion 4 in the roll direction 17 is normally 1/1000 to 1/2000, which is sufficiently soft as compared with the rigidity of the air film in the direction perpendicular to the medium surface between the slider 2 and the medium. Even if the holding portion 9 is tilted, the slider mounting surface 10 is not tilted, and the attitude of the slider 2 is hardly affected. Examples will be quantitatively shown below. The tip of the left piezoelectric actuator 7a and the right piezoelectric actuator 7b
When the distance between the tips of the piezoelectric actuator 7 is 2 mm and the step between the tip 8 of the piezoelectric actuator 7 and the holding portion 9 of the gimbal 4 is 0.2 mm, when the tip of the piezoelectric actuator 7 operates ± 5 μm, The tip portion 8 of the actuator 7 and the holding portion 9 of the gimbal portion 4 are inclined ± 0.29 degrees, and the gimbal portion 4, the slider 2, and the head element 1 are continuously moved by ± 1 μm in the horizontal direction in the figure. The inclination of the slider 2 depends on the gimbal portion 4
When the ratio of the rigidity in the roll direction 17 to the rigidity of the air film in the direction perpendicular to the medium surface between the slider 2 and the medium is 1/1500,
2.9 / 15000 degrees and the width of the slider 2 is 1 mm
In the case of the pico slider, the change in the flying height at the end of the slider 2 is only 1.7 nm. The change in the flying height at the center of the slider 2 on which the element 1 is mounted is 1 nm or less. In this case, the moving distance 11 of the head element 1
Is 1/5 of the operating distance of the piezoelectric actuator 7, and the accuracy is 5 times.

An example of a method of manufacturing the suspension 3 will be described with reference to the drawings. FIG. 3 is a process chart of the BB sectional view of FIG. Hereinafter, description will be made in order. Base material 1
2 is molded (FIG. 3 (a)). When the material of the base material 12 is silicon, it is wet or dry-etched, and when the material is a stellenless material, the outer shape is cut out by etching, laser processing or pressing, and then press-molded. Next, the insulating film 13 is formed on the base material 12 (see FIG. 3).
(B)). When the material of the base material 12 is silicon, thermal oxidation,
Alternatively, silicon nitride or silicon oxide is deposited. When the material of the base material 12 is a stainless material, polyimide is applied and baked. A Ti film 14 is formed by Ti sputtering (FIG. 3C). By the shadow mask method or the lift-off method, the lead zirconate titanate is formed on the Ti film 14 only in the region to be grown. Further, a lead zirconate titanate film 15 is grown on this by hydrothermal addition (FIG. 3).
(D)). Lead zirconate titanate film 15 by hydrothermal addition
For example, the method of growing FC is FC Report 1
No. 3 (1995) No. 8, page 214, FIG. The wiring 16 is formed by plating or the like (see FIG. 3).
(E)). This completes the suspension 3.

An example in which the head support mechanism 21 with a fine movement actuator described above is mounted on a magnetic disk device,
This will be described with reference to the drawings. FIG. 4 is a perspective view showing the inside of the enclosure 22 of the mechanism portion of the magnetic disk device using the head support mechanism 21 with the fine movement actuator. The head element 1 is a head support mechanism 21 with a fine movement actuator.
And an information recording medium 24 by the coarse motion actuator 23.
Positioned at any position above. The coarse motion actuator 23 is driven by a voice coil motor 25 which is widely used in general magnetic disk devices. The fine movement actuator and the coarse movement actuator 23 of the head support mechanism 21 with the fine movement actuator may be controlled in the same manner as, for example, the two-stage servo system of the optical disk device.

As described above, in this embodiment, the actuator for the two-stage servo can be constructed, the positioning accuracy of the head element 1 of the information recording apparatus can be made high, and the recording density of the information recording apparatus can be improved. There is an effect. Further, in the present embodiment, since the displacement of the head element 1 in the horizontal direction is reduced to one fifth of the displacement in the upward direction of the piezoelectric actuator 7, the head is 5 times more accurate than the piezoelectric actuator 7. The element 1 can be positioned, higher positioning accuracy can be realized as compared with the known example, and the recording density of the information recording apparatus can be significantly improved. Further, since the suspensions 3 can be collectively manufactured by a batch process, there is an effect that an inexpensive head support mechanism can be realized.

Although the magnetic disk device has been described above, an information recording device in the form of enhancing SNOM or AFM (atomic force microscope) has a structure similar to that of the present embodiment, so that it can be used for a two-stage servo. An actuator can be configured and the same effect as that of this embodiment can be obtained.

The positioning of the head element 1 in the present embodiment has been described above. Next, when the recording medium 24 starts rotating, the recording medium 24 and the slider 2 will be described.
A description will be given of how to release the adhesion between In the magnetic disk device of FIG. 4, the slider 2 is in contact with the recording medium 24 when the recording medium 24 does not rotate. Therefore, if the recording medium 24 is stopped for a certain period of time, the recording medium 24 and the slider 2 will stick or stick to each other. A large amount of torque is required to rotate the recording medium 24 in the state where adhesion or adsorption occurs, and a large amount of electric power is required to rotate the recording medium 24 with an electromagnetic motor. Further, when the power is insufficient, the recording medium 24 may not rotate. In order to solve such a problem, the suspension 3 is repeatedly twisted by the above-mentioned driving principle immediately before the rotation of the recording medium 24 is started. By twisting the suspension 3, a force in the roll direction 17 is applied to the slider 2 as shown in FIG. The slider 2 is peeled off from the recording medium 24 by repeating the operation. Once the slider 2 and the recording medium 24 are peeled off, the coefficient of friction between them becomes small, and therefore the torque required to rotate the recording medium 24 becomes small. If the frequency of the torsion of the suspension 3 is made equal to the natural frequency of the screw of the suspension 3, the ratio of the force for peeling the slider 2 from the recording medium 24 to the input voltage of the piezoelectric actuator 7 can be increased.

[0026]

According to the head support mechanism of the present invention, the head element 1 can be positioned with higher accuracy than that of the piezoelectric actuator 7, and the positioning accuracy of the head element can be sufficiently obtained. Therefore, it is possible to perform the positioning of the head element 1 with higher accuracy than the fine movement actuator of the conventional two-stage actuator.

According to the information recording apparatus of the present invention, the recording density of the information recording apparatus in the track width direction can be improved. Also,
An information recording device having a high recording density can be realized.

[Brief description of drawings]

FIG. 1 is a perspective view of a head support mechanism showing an embodiment of the present invention.

FIG. 2 is an operation explanatory diagram when FIG. 1 is viewed from a direction A.

3 is a process chart of the BB cross-sectional view of FIG.

FIG. 4 is a perspective view of a magnetic disk device using a head support mechanism according to the present invention.

FIG. 5 is a diagram showing a conventional head support mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Head element 2 ... Slider 3, 31 ... Suspension 4 ... Gimbal part 5 ... Road arm part 6, 61 ... Mount part 7 ... Piezoelectric actuator 8 ... Piezoelectric actuator tip part 9 ... Gimbal part Holding part 10 ... Slider mounting surface 11 ... Head element moving distance 12 ... Base material 13 ... Insulating film 14 ... Ti film 15 ... PZT film 16 ... Wiring 17 ... Roll direction 22 ... Enclosure 23 ... Fine movement actuator 24 ... Recording medium 25 ... Voice coil motor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenji Mori 2880, Kozu, Odawara-shi, Kanagawa Stock Company Hitachi Storage Systems Division

Claims (10)

[Claims] 1. An information recording apparatus comprising a disk-shaped recording medium and a recording / reproducing head arranged so as to face a recording track of the recording medium, the recording / reproducing head being held and slid on the recording medium. A flying slider, a head support mechanism for joining the slider and an actuator of the device, and an actuator for the slider and the head support mechanism.
And a means for twisting a part or the whole of the head support mechanism about a straight line in a plane including a straight line connecting the connecting portion with the recording head and the track width direction of the recording / reproducing head by the twisting motion of the head support mechanism. An information recording apparatus having a positioning means for performing minute positioning. 2. The head support mechanism according to claim 1, wherein the displacement of the means for twisting the head support mechanism is reduced to generate a minute displacement in the track width direction of the recording / reproducing head. 3. A two-stage actuator is constituted by the positioning mechanism and a positioning mechanism for a main actuator of an apparatus equipped with one or a plurality of head supporting mechanisms. Information recording device described. 4. A head supporting mechanism for mounting a recording / reproducing head and holding a slider sliding or flying on a recording medium, wherein an actuator for causing the head supporting mechanism to vertically displace relative to a slider air bearing surface. Are arranged at both ends of the head support mechanism, and one actuator is operated or both actuators are differentiated, so that a portion provided at the tip of the actuator of the head support mechanism is moved to the slider and the head. A head support mechanism characterized by twisting about a straight line in a plane including a straight line connecting a connecting portion of the support mechanism with an actuator. 5. A small displacement in the track width direction of the recording / reproducing head is generated by reducing the displacement of twisting the head support mechanism by operating the actuator or differentially operating both actuators. The head support mechanism according to claim 4, wherein 6. A head supporting mechanism for mounting a recording / reproducing head and holding a slider sliding or flying on a recording medium, a means for causing the head supporting mechanism to generate a displacement perpendicular to the recording medium surface, and a recording medium surface. And a means for converting a displacement perpendicular to the recording medium surface into a horizontal displacement on the recording medium surface, and positioning the recording / reproducing head in the track width direction by the horizontal displacement on the recording medium surface. . 7. A head support mechanism having means for generating a displacement perpendicular to the recording medium surface and means for converting the displacement perpendicular to the recording medium surface into a displacement horizontal to the recording medium surface, and horizontal to the recording medium surface. In the head support mechanism that positions the recording / reproducing head in the track width direction by various displacements, the displacement perpendicular to the recording medium surface is reduced when it is converted into the horizontal displacement on the recording medium surface, and the displacement generating means is more accurate. 7. The head support mechanism according to claim 6, wherein positioning in the track width direction is increased. 8. An information recording apparatus comprising a disk-shaped recording medium and a recording / reproducing head arranged so as to oppose a recording track of the recording medium, using the head supporting mechanism according to any one of claims 4 to 7. / An information recording apparatus characterized by performing minute positioning of a reproducing head in the track width direction. 9. An information recording comprising a disk-shaped recording medium and a recording / reproducing head arranged to face a recording track of the recording medium, the recording medium and the head being in contact with each other when the apparatus is stopped. In an apparatus, using the head support mechanism according to any one of claims 4 to 7, the head support mechanism is repeatedly twisted just before the rotation of the recording medium of the apparatus is started to release adsorption or adhesion of the head and the recording medium. Characterized information recording device. 10. The information recording apparatus according to claim 9, wherein the frequency of repetitive twisting of the head support mechanism is made substantially equal to the natural frequency of torsion of the head support mechanism.