JP2001052456A - Suspension, information recording/reproducing device using the same, and driving method for the information recording/reproducing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly precise and efficient suspension for disk device capable of finely displacing a head for the tracking correction or the like of the head. SOLUTION: This suspension 100 is provided with a head 26 for at least recording/reproducing data on a rotary-driven disk, a slider 24 having the head 26 loaded thereon, and a plate elastic body 18 in which the slider 24 is mounted on its one end. The plate elastic body 18 has a pair of plate-like arm parts, at least two piezoelectric thin films 36, 38, 40 and 42 are formed in the respective arm parts, and a driving means is further provided to apply voltages in the thickness directions of the respective piezoelectric thin films 36, 38, 40 and 42 such that the head 26 is finely moved in the radial direction of the disk.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generally relates to a disk device such as a magnetic disk device suitable for high-density recording, and more particularly to a disk device for recording and / or reproducing data on a disk in the disk device. Suspension that supports

[0002]

2. Description of the Related Art In recent years, magnetic disk devices having one or more magnetic disks that are rotationally driven as data recording media have been widely used as external storage devices for computers. With the adoption of an MR head (recording / reproducing head having a magnetoresistive head as a read-only head) and the like, the recording density of a magnetic disk device is increasing year by year. Limiting the tracking of a head to a track by using only an electromagnetic actuator has reached its limit. Therefore, a number of magnetic disk devices have been provided which employ a suspension having a head minute displacement mechanism and perform tracking correction.

FIG. 11 is a plan view showing a conventional suspension 1100 of a magnetic disk drive. This is an example of the prior art and is a journal of the Japan Society of Applied Magnetics, Vol.
4), page 867, FIG. A head 2 for recording / reproducing data on a rotationally driven magnetic disk (not shown) is supported at once by a suspension arm 4, and the other end of the suspension arm 4 has a small angle around a projection 8 of a carriage 6. It is rotatably supported within the range.

The carriage 6 is rotatable about a shaft member 10 fixed to a housing of the magnetic disk drive. By controlling an exciting current flowing through a drive coil 14 which is a part of a magnetic circuit 12 fixed to the housing side with respect to a permanent magnet (not shown) fixed to the carriage 6, the carriage 6 It turns around. Thus, the head 2 can be moved in the substantially radial direction of the magnetic disk (the direction of the arrow A1).

[0005] A piezoelectric thin film 16 is interposed between the carriage 6 and the suspension arm 4. By expanding and contracting the piezoelectric thin film 16 in the directions of arrows A2 and A3 in the drawing, the suspension arm 4 operates in the same manner within a small angle range with respect to the carriage 6, whereby the head 2 is slightly displaced.

[0006]

In the conventional suspension 1100 shown in FIG. 11, both ends of the piezoelectric thin film 16 in the longitudinal direction are in contact with the suspension arm 4 and the carriage 6, respectively. Conventional suspension 110
In the case of 0, the head 2 is slightly displaced by the enlarged displacement due to the bulk deformation of the piezoelectric thin film 16. Therefore, the piezoelectric thin film 1
There is a problem that the head 2 cannot be minutely displaced efficiently with respect to the voltage applied to the head 6. Further, there is a problem that a high voltage must be applied to the piezoelectric thin film 16.

SUMMARY OF THE INVENTION An object of the present invention is to provide a suspension of a disk drive capable of performing a highly accurate and efficient minute displacement for tracking correction or the like of a head.

It is another object of the present invention to provide a suspension of a disk drive capable of performing a high-precision minute displacement by applying a low voltage to a piezoelectric thin film.

[0009]

A suspension according to the present invention comprises a head for recording or reproducing at least data on a rotationally driven disk, a slider on which the head is mounted, and the slider at one end. A suspension including a mounted plate-like elastic body, wherein the plate-like elastic body has a pair of plate-like arm portions, and at least two piezoelectric thin films are formed on each of the plate-like arm portions,
A drive unit for applying a voltage in a thickness direction of each of the piezoelectric thin films so that the head is finely driven in a radial direction of the disk is further provided, thereby achieving the above object.

The pair of plate-shaped arms may be arranged in a fan shape from the head toward the other end of the plate-shaped elastic body.

The angle formed by the pair of plate-like arms is 1
It may be 80 degrees or less.

[0012] The driving means may apply a voltage to each of the piezoelectric thin films so that the head makes a rotational movement.

[0013] The plate-shaped arm portion may have a first surface, and the plate-shaped arm portion may be arranged such that the first surface is substantially perpendicular to a recording / reproducing surface of the disk. .

The piezoelectric thin film includes a first piezoelectric thin film and the first piezoelectric thin film.
A second electrode formed on the opposite side of the head to the piezoelectric thin film;
And a piezoelectric thin film.

[0015] The pair of plate-like arms may be arranged substantially parallel from the head toward the other end of the plate-like elastic body.

The plate-shaped arm may have a first surface, and the plate-shaped arm may be arranged such that the first surface is substantially perpendicular to a recording / reproducing surface of the disk. .

[0017] The driving means may apply a voltage to each of the piezoelectric thin films so that the head performs a translational movement.

The piezoelectric thin film includes a first piezoelectric thin film and the first piezoelectric thin film.
A second electrode formed on the opposite side of the head to the piezoelectric thin film;
And a piezoelectric thin film.

At least four piezoelectric thin films are formed on each of the plate-like arm portions, and the piezoelectric thin films are formed on a first piezoelectric thin film and a second piezoelectric thin film formed on a side opposite to the head with respect to the first piezoelectric thin film. A piezoelectric thin film, wherein each of the plate-shaped arms has a first surface and a second surface formed on the opposite side of the first surface, and wherein the first piezoelectric thin film is provided on the first surface. A third piezoelectric thin film to be formed and a fourth piezoelectric thin film to be formed on the second surface.
A second piezoelectric thin film formed on the first surface and a sixth piezoelectric thin film formed on the second surface.
And a piezoelectric thin film.

The fourth piezoelectric thin film may be formed on the back side of the position where the third piezoelectric thin film is formed, and the sixth piezoelectric thin film may be formed on the back side of the position where the fifth piezoelectric thin film is formed. Good.

The piezoelectric thin film may be arranged so that the head is slightly displaced by applying a voltage of the same polarity.

The piezoelectric thin film includes a first piezoelectric thin film and the first piezoelectric thin film.
A second electrode formed on the opposite side of the head to the piezoelectric thin film;
A piezoelectric thin film, wherein each of the plate-shaped arms has a first surface and a second surface formed on the opposite side of the first surface, and wherein the first piezoelectric thin film is provided on the first surface. The formed second piezoelectric thin film may be formed on the second surface, and the first piezoelectric thin film and the second piezoelectric thin film may not be formed on the front and back, respectively.

The thickness of the piezoelectric thin film is 1 μm or more and 10 mm
It may be as follows.

The piezoelectric thin film is made of PZT, PLT, ZnO
And polyvinylidene fluoride (PVDF).

An information recording / reproducing apparatus according to the present invention is an information recording / reproducing apparatus for recording / reproducing information on / from a disk. A suspension having a slider on which the head is mounted, and a plate-like elastic body having the slider mounted on one end, wherein the plate-like elastic body has a pair of plate-like arm portions, At least two piezoelectric thin films are formed on each of the parts,
A suspension further comprising driving means for applying a voltage in a thickness direction of each of the piezoelectric thin films so that the head is finely driven in a radial direction of the disk; and a main unit for executing coarse positioning of the head with respect to the disk. Driving means, whereby the above object is achieved.

The information recording / reproducing apparatus moves the head in the radial direction of the disk by applying a voltage in the thickness direction of the piezoelectric thin film of the plate-shaped arm portion after performing the coarse positioning of the head. Then, fine positioning may be performed.

[0027] The pair of plate-shaped arms may be arranged in a fan shape from the head toward the other end of the plate-shaped elastic body.

[0028] The pair of plate-like arms may be arranged substantially parallel from the head toward the other end of the plate-like elastic body.

[0029] The driving means may apply a voltage to each of the piezoelectric thin films so that the head performs a translational movement.

The thickness of the piezoelectric thin film is 1 μm or more and 10 mm
It may be as follows.

The piezoelectric thin film is made of PZT, PLT, ZnO
And polyvinylidene fluoride (PVDF).

A method for positioning an information recording / reproducing apparatus according to the present invention is a method for positioning an information recording / reproducing apparatus for recording / reproducing information on / from a disk, wherein the information recording / reproducing apparatus is adapted to rotate and A suspension for recording or reproducing data at least, a slider having the head mounted thereon, and a plate-shaped elastic body having the slider mounted at one end, wherein the plate-shaped elastic body comprises a pair. At least two piezoelectric thin films are formed on each of the plate arm portions, and the thickness of each of the piezoelectric thin films is set so that the head is finely driven in the radial direction of the disk. A suspension further comprising driving means for applying a voltage in the direction;
A main drive unit for performing coarse positioning of the head with respect to the disk, a first step of performing coarse positioning of the head with respect to the disk, and the head is finely driven in a radial direction of the disk. And a second step of applying a voltage in the thickness direction of each of the piezoelectric thin films, whereby the object is achieved.

The pair of plate-like arms includes a first arm and a second arm, and the piezoelectric thin film includes a first piezoelectric thin film, a second piezoelectric thin film, and a second arm formed on the first arm. A third piezoelectric thin film and a fourth piezoelectric thin film formed on the head, the second piezoelectric thin film is formed on the opposite side of the head with respect to the first piezoelectric thin film, and the fourth piezoelectric thin film is formed on the fourth piezoelectric thin film. 3 is formed on the opposite side of the head with respect to the piezoelectric thin film, and the second step comprises:
Applying a voltage of a first polarity to the piezoelectric thin film; and applying a voltage of a second polarity different from the first polarity to the second piezoelectric thin film and the fourth piezoelectric thin film. May be.

[0034] The pair of plate-shaped arms may be arranged in a fan shape from the head toward the other end of the plate-shaped elastic body.

[0035] The pair of plate-shaped arms may be arranged substantially parallel from the head toward the other end of the plate-shaped elastic body.

The pair of plate-like arms includes a first arm and a second arm, and the first arm has a first surface and a second surface formed on the opposite side of the first surface. And the second
The arm has a third surface and a fourth surface formed on the opposite side of the third surface, and the piezoelectric thin film has a first piezoelectric thin film formed on the first surface of the first arm and a fourth thin film. (2) a piezoelectric thin film, a third piezoelectric thin film and a fourth piezoelectric thin film formed on the second surface of the first arm, and a fifth piezoelectric thin film and a sixth piezoelectric thin film formed on the third surface of the second arm. And a seventh piezoelectric thin film and an eighth piezoelectric thin film formed on the fourth surface of the second arm. The second piezoelectric thin film and the fourth piezoelectric thin film include the first piezoelectric thin film and the third piezoelectric thin film. The sixth piezoelectric thin film and the eighth piezoelectric thin film are formed on opposite sides of the head with respect to each of the piezoelectric thin films, and the head is formed with respect to each of the fifth piezoelectric thin film and the seventh piezoelectric thin film. And the second step includes forming the first piezoelectric thin film and the fourth
Applying a voltage of a first polarity to the piezoelectric thin film, the sixth piezoelectric thin film, and the seventh piezoelectric thin film; and applying the second piezoelectric thin film, the third piezoelectric thin film, the fifth piezoelectric thin film, and the eighth Applying a voltage having a second polarity different from the first polarity to the piezoelectric thin film.

[0037] The second step may include a step of applying a voltage of a first polarity to all the piezoelectric thin films.

The piezoelectric thin film includes a first piezoelectric thin film and the first piezoelectric thin film.
A second electrode formed on the opposite side of the head to the piezoelectric thin film;
A piezoelectric thin film, wherein each of the plate-shaped arms has a first surface and a second surface formed on the opposite side of the first surface, and wherein the first piezoelectric thin film is provided on the first surface. The formed second piezoelectric thin film may be formed on the second surface, and the first piezoelectric thin film and the second piezoelectric thin film may not be formed on the front and back, respectively.

According to one aspect of the present invention, for example,
And the fourth piezoelectric thin film expands and contracts in the same phase, respectively, and applies the same voltage signal to the first and fourth electrode pairs so that the second and third piezoelectric thin films expand and contract in the opposite phases, respectively. By applying a reverse voltage signal to the third electrode pair, highly accurate and efficient minute displacement for tracking correction can be achieved. Further, the on-track can be more reliably performed by performing the translational motion.

According to another aspect of the present invention, there is provided a suspension of a disk device capable of generating a large driving force with respect to a low voltage, or an information recording / reproducing apparatus using the same.

According to still another aspect of the present invention, there is provided a suspension of a disk device in which all the piezoelectric thin films have only the same polarity and can expand and contract similarly, or an information recording / reproducing apparatus using the same.

According to still another aspect of the present invention, there is provided a suspension of a disk device capable of reducing the number of wirings for applying a voltage to the piezoelectric thin film or an information recording / reproducing apparatus using the same.

[0043]

Embodiments of the present invention will be described below in detail. FIG. 1 is a plan view showing a suspension 100 according to an embodiment of the present invention. A gimbal 20 is formed on one end of a substantially rectangular shape made of a plate-like elastic body such as a stainless steel plate by punching or etching, and a head 26 is mounted on the gimbal 20.

The head 26 is provided with a slider 24 so as to float at a predetermined distance from the magnetic disk which is driven to rotate.
have. A head 26 including an MR element and a plurality of (four in this example) terminals 27 for connecting the head 26 to an external circuit are formed on an end surface of the slider 24. Rails 28 and 30 having a predetermined shape are formed on the bottom surface (on the paper surface) of the slider 24 to generate an appropriate airflow between the slider 24 and the rotating magnetic disk.

The load beam 18 is formed of a plate-like elastic body in order to obtain a required flying height of the head 22 by balancing the elastic force of the load beam and the floating force of the slider 24. Bends are formed on both sides of the load beam 18 for adjustment.

The four terminals 27 of the head 22 are connected to signal patterns 32A, 32B,
32C and 32D are respectively connected by ball bonding. Signal patterns 32A, 32B, 32C
And 32D are each connected to four bonding pads 34 formed on the load beam 18 on the side opposite to the head 26.

On the surface (the first surface) of the load beam 18 on which the head 26 is mounted, approximately α in the longitudinal direction.
Piezoelectric thin films 36, 38, 40 and 42 are provided at an angle of degrees. The piezoelectric thin films 36, 38, 40 and 42 exist in the same region (in the secondary plane).

The bonding pad 3 of the load beam 18
A base plate (not shown) is attached on the second surface at the end on the side of the fourth side to increase rigidity, and a shaft member for rotating the load beam 18 is attached to the base plate and the load beam 18. Hole 46 is formed.
The hole 48 at the approximate center of the load beam 18 is for positioning.

The piezoelectric thin films 36 and 38 are bonded to bonding pads 52 by signal patterns 51 and 53, respectively.
And 54, and the piezoelectric thin films 40 and 42
The signal pads 56 and 60 formed on the second surface of the load beam 18 respectively cause the bonding pads 5
8 and 62.

FIG. 2 is a sectional view taken along line AA in FIG.
An insulating layer 64 is formed on the gimbal 20, and the piezoelectric thin films 40 and 42 and the signal pattern 32 for the head 26 are formed.
A, 32B, 32C and 32D, and the piezoelectric thin films 40 and 4
Two signal patterns 56 and 60 are provided on the insulating layer 64.

An insulating layer 66 is formed on the gimbal 20, and the piezoelectric thin films 40 and 42 and the piezoelectric thin films 40 and 4 are formed.
Two signal patterns 56 and 60 are provided on the insulating layer 66.

Each of the piezoelectric thin films 36, 38, 40 and 42 has
Each of the electrode layers 68, the piezoelectric thin film 72, and the electrode layer 74 is laminated in this order from the insulating layer 64 side.

The electrode layers 68 and 74 are made of a metal such as Au. As the material of the piezoelectric thin film 72, ZnO oriented by sputtering or the like can be used. As the piezoelectric thin film 72, in addition to the ZnO thin film, PZT, PL
A thin film having a perovskite structure such as ZT or barium titanate can be used.

Next, FIG. 3 shows a structure in which the load beam 18 is bent by 90 ° in the direction indicated by the thick arrow B in FIG. In FIG. 3, reference numeral 76 denotes piezoelectric thin films 36, 38,
The electrode layers 74 of 40 and 42 are connected to the signal
1, bonding wires for connection to 1, 53, 56 and 60 are shown. Piezoelectric thin films 36.38, 40 and 4
The two electrode layers 68 (FIG. 2) are grounded by ground patterns (not shown). Each piezoelectric thin film 36, 3
In 8, 40 and 42, the thickness of the piezoelectric thin film 72 is, for example, about 1 to 3 mm.

When a voltage is applied to the piezoelectric thin films 36, 38, 40, and 42, the piezoelectric thin films 36, 38, 40, and 42 expand and contract in the thickness direction (arrow A4 direction) (D33 mode), while being orthogonal to the thickness. It also expands and contracts in the direction (arrow A5 direction), especially in the longitudinal direction of the piezoelectric thin films 36, 38, 40 and 42 (d31 mode). In the present embodiment, this d3
Piezoelectric thin films 36, 38, 40 and 42 for one mode
The tracking correction of the head 26 and the like are performed using the expansion and contraction of the head.

FIGS. 4A and 4B are explanatory diagrams of the operation of the suspension 100 in the present embodiment. In tracking correction, when the head 26 is slightly displaced in the radial direction of the magnetic disk (the direction of arrow A6, hereinafter sometimes simply referred to as “radial direction”), the piezoelectric thin films 36 and 42 are provided as shown in FIG. 4B. Expands and contracts in phase, and the piezoelectric thin film 3
A voltage signal is applied to each piezoelectric thin film so that 8 and 40 expand and contract in opposite phases.

For example, when the piezoelectric thin films 36 and 42 are expanded and the piezoelectric thin films 38 and 40 are contracted by such a voltage signal, the gimbal 20 is carried vertically in the plane of the drawing and the head 2
6 is slightly displaced in the radial direction as indicated by a solid arrow 78.

Referring to FIG. 4C, on the other hand, when a voltage signal is applied so that the piezoelectric thin films 36 and 42 contract and the piezoelectric thin films 38 and 40 expand, the head 26 moves in the radial direction as indicated by an arrow 80. Is slightly displaced in the opposite direction.

FIG. 5 shows an example of the voltage signal waveform in this case.
Shown in 5, reference numerals 136, 138, 140 and 142 denote waveforms of voltage signals applied to the piezoelectric thin films 36, 38, 40 and 42, respectively.

In the period of time (t1 to t2), the head 26 is slightly displaced in the direction indicated by the arrow 78 in FIG. 4B, and during this period, each of the piezoelectric thin films 36, 38, 40
And 42 are provided with controlled voltage signal waveforms for tracking correction. In accordance with the principles described above, voltage signal waveforms 136 and 138 are out of phase with each other, voltage signal waveforms 136 and 142 are in phase, and voltage signal waveforms 138 and 140 are in phase.

During the period of time (t2 to t3), tracking correction is not performed, and during this period, for example, rough tracking is performed by the electromagnetic actuator, and coarse movement positioning is performed.

During the period of time (t3 to t4), the head 2
6 is slightly displaced in a direction indicated by an arrow 80 in FIG. 4C, and controlled voltage signal waveforms 136, 138, 140 and 142 for tracking correction are applied to the piezoelectric thin films 36, 38, 40 and 42 during this period. Each is given.

In this embodiment, when one side of the gimbal 20 (the member on which the piezoelectric thin films 36 and 38 are present) receives a force in the contracting direction, the other side receives a force in the pulling direction. The head 26 can be largely rotated about the pressing load position (rotation center), and effective minute displacement can be achieved.

Further, each of the piezoelectric thin films 36, 38, 40 and 4
Since the reproducibility of the amount of expansion and contraction per unit applied voltage of 2 is good, highly precise minute displacement of the head 26 is possible.

Further, a static voltage is applied to each of the piezoelectric thin films 36, 3
It was also confirmed that when the voltage was applied to 8, 40 and 42, the same position was maintained for a long time. FIG. 6 shows an example of the voltage signal waveform in this case. In FIG. 6, reference numerals 236 and 23
8, 240 and 242 are respectively piezoelectric thin films 36, 3 when the head 26 is statically displaced in the left-right direction.
8 shows voltage waveforms applied to 8, 42 and 40. Voltage waveforms 236 and 242 are in phase, and voltage signal waveform 23
8 and 240 are out of phase with respect to the voltage waveforms 236 and 242.

During the period of time (t5 to t6), a DC voltage is applied to each of the piezoelectric thin films 36, 38, 40 and 42. According to the amplitude of the voltage waveform, the head 26 becomes a solid line in FIG. 4B. The head is maintained in a state of being slightly displaced in the direction indicated by the arrow 78, whereby a desired distance is obtained between the head 26 before the voltage is applied and the head 26 after the voltage is applied.

FIG. 7 shows another suspension 200 according to the embodiment of the present invention. FIG. 7 is a plan view after the load beam 18 has been bent substantially 90 ° in the direction indicated by the arrow B.

The piezoelectric thin films 36, 38, 40 and 42 are respectively formed as shown in FIG. 2, and the piezoelectric thin films 46, 48, 50 and 52 are formed on the back side of the arms. . The advantage is that the force generated with respect to the applied voltage can be doubled by forming the piezoelectric thin film on the front and back, so that the head can be displaced at a low voltage even when a larger external force is applied. Is a point.

When the head is moved to the upper side of the drawing, a negative voltage is applied to the piezoelectric thin films 36, 48, 50 and 42, and a positive voltage is applied to the remaining piezoelectric thin films 38, 46, 40 and 52. Good. Piezoelectric thin films 36, 38,
It has been found that the driving force can be substantially doubled to 100 mgf by applying the same voltage as compared with the suspension 100 shown in FIG. 3 in which only 40 and 42 are arranged.

Also, as shown in FIG. 8, the number of piezoelectric thin films is reduced from that shown in FIG. 7, and the piezoelectric thin films 36, 48, 50 and 42 are reduced.
By using only the negative voltage, the head 22 could be driven upward on the paper as indicated by the arrow 82 only by applying a negative voltage of the same polarity. Also, by applying a positive voltage, the head can be moved downward (arrow 84) on the paper surface,
The voltage applied to the piezoelectric thin film can be made only one polarity. Specifically, it was confirmed from the Doppler displacement meter that the head 22 was displaced by 1 mm when a voltage of 4 V was applied.

FIG. 3 shows a structure in which the load beam 18 is bent substantially 90 ° so that the piezoelectric thin film is located outside.
However, the present invention is not limited to this. The load beam 18 is substantially 90 degrees so that the piezoelectric thin film is on the inside.
Even when bent, the same minute displacement can be obtained for the same voltage.

In the suspension 100 according to the embodiment, when the head 26 is displaced in the radial direction, the thickness of the load beam 18 is 40 mm, and the thickness of the piezoelectric thin film 74 is 2 m.
When the voltage applied between the electrode layers 60 and 74 is 3 V, the displacement of the head 26 can be, for example, 1.0 mm.

On the surface on which the head 26 is mounted, the piezoelectric thin films 36,
The state in which 38, 40 and 42 are provided is as shown in FIG. 1, but the piezoelectric thin films 36, 38, 40 and 42 are provided.
Are arranged so that they are parallel to each other.
0 is shown in FIG.

The difference from the operation of the suspension 100 shown in FIG. 4 is that the suspension 400 is performing a translational movement. By changing from the rotational drive shown in FIG. 4 to the translation drive, it was possible to make a minute displacement to the intended track groove with a small applied voltage. In the case of the translation drive system to move the same displacement amount as the actual rotation drive system,
The voltage applied to the piezoelectric thin films 36, 38, 40 and 42 is 2
/ 3 of 2V.

In FIG. 10B, when the piezoelectric thin films 36 and 42 are expanded and the piezoelectric thin films 38 and 40 are contracted by the voltage signal, the gimbal 20 is carried upward in the plane of the paper, and the head 26 is slightly displaced as indicated by a solid arrow 86. I do.

Referring to FIG. 10C, piezoelectric thin films 36 and 4
When the voltage signal is applied so that 2 contracts and the piezoelectric thin films 38 and 40 expand, the head 26 slightly displaces in the radial direction as shown by the arrow 88 in the opposite direction.

FIG. 5 shows an example of the voltage signal waveform in this case.
Can be written substantially the same as Furthermore, it was confirmed that a static voltage was applied to each piezoelectric thin film, and the piezoelectric thin film was maintained at the same position for a long time. The voltage signal waveform in this case is also shown in FIG.
Is substantially the same as

Further, by forming a piezoelectric thin film on both the front and back sides, the force generated for the same applied voltage is doubled as in FIGS. 7A and 7B, so that even when a larger external force is applied, a minute displacement can be obtained. Became possible.

As shown in FIGS. 8A and 8B, by reducing the number of piezoelectric thin films, the head 26 can be driven as shown by arrows 82 and 84 only by applying the same polarity voltage. This makes it possible to reduce the number of wirings to be applied to the piezoelectric thin film.

In FIGS. 10A to 10C, the piezoelectric thin films 36, 38, 40, and 42 are bent so as to be located on the outside. A small displacement could be obtained.

In the above embodiment, when the head 26 is displaced in the radial direction, the thickness of the load beam 18 is 2
When the thickness of the piezoelectric thin film 74 is 2 μm and the voltage applied between the electrode layers 60 and 74 is 3 V, the displacement of the head 26 can be 0.8 μm, for example.

[0082]

As described above, according to the present invention, it is possible to provide a suspension of a disk drive capable of performing highly accurate and efficient minute displacement for tracking correction and the like for a head.

Further, according to the present invention, it is possible to provide a suspension of a disk device capable of performing high-precision minute displacement by applying a low voltage to the piezoelectric thin film.

[Brief description of the drawings]

FIG. 1 is a plan view of a rotationally driven suspension according to an embodiment of the present invention.

FIG. 2 is an AA sectional view showing the piezoelectric thin film in FIG.

FIG. 3 is a plan view of the suspension bent substantially perpendicularly at a thick line portion B in FIG. 1;

FIG. 4A is an operation explanatory view of the suspension according to the embodiment shown in FIG. 3;

FIG. 4B is an operation explanatory view of the suspension according to the embodiment shown in FIG. 3;

FIG. 4C is an operation explanatory diagram of the suspension according to the embodiment shown in FIG. 3;

FIG. 5 is a diagram showing an example of a voltage signal waveform for moving the head according to the embodiment.

FIG. 6 is a diagram showing a waveform of an electrostatic voltage signal required to move and hold the head according to the embodiment for a long time.

FIG. 7A is an explanatory diagram of the operation of the suspension in the embodiment after bending in which the piezoelectric thin film is disposed on each of the front and back sides of the arm portion.

FIG. 7B is an explanatory diagram of the operation of the suspension in the embodiment after bending in which the piezoelectric thin film is disposed on each of the front and back sides of the arm portion.

FIG. 8A is an explanatory diagram of an operation in an embodiment in which a head can be moved with only a voltage having the same polarity.

FIG. 8B is an operation explanatory diagram in the embodiment in which the head can be moved with only the same polarity of the voltage.

FIG. 9 is a plan view of a translationally driven suspension according to the embodiment.

FIG. 10A is an operation explanatory diagram of a translationally driven suspension according to the embodiment shown in FIG. 9;

FIG. 10B is an operation explanatory diagram in the translationally driven suspension according to the embodiment shown in FIG. 9;

10C is an explanatory diagram of the operation in the translationally driven suspension according to the embodiment shown in FIG. 9;

FIG. 11 is a plan view showing an example of a conventional suspension of a magnetic disk drive.

[Explanation of symbols]

 Reference Signs List 18 load beam 36, 38, 40, 42 piezoelectric thin film 72 piezoelectric thin film 2 head 4 suspension arm 6 carriage 8 protrusion 10 shaft member 12 magnetic circuit 14 drive coil 16 piezoelectric thin film 20 gimbal 24 slider 26 head unit 27 four terminals 28, 30 Rail 32A, 32B, 32C, 32D Signal pattern 34 Bonding pad 44 Plate 48 Center hole 51, 53 Signal pattern 52, 54 Bonding pad 56, 60 Signal pattern 58, 62 Bonding pad 64 Insulating layer 66 Insulating layer 68 Electrode layer 74 Electrode layer 80 Arrow 136,138 Voltage signal waveform 140,142 Voltage signal waveform 236,238,240,242

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Kenichi Sakamoto 1006 Kazuma Kadoma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. Terms (reference) 5D068 AA01 BB01 CC11 EE15 GG03 GG24 5D096 NN03 NN07

Claims (30)

[Claims] 1. A suspension comprising: a head for recording or reproducing at least data on a rotationally driven disk; a slider equipped with the head; and a plate-like elastic body equipped with the slider at one end. The plate-like elastic body has a pair of plate-like arm portions, at least two piezoelectric thin films are formed on each of the plate-like arm portions, and the head is finely driven in a radial direction of the disk. And a driving means for applying a voltage in a thickness direction of each of the piezoelectric thin films. 2. The suspension according to claim 1, wherein the pair of plate-shaped arm portions are arranged in a fan shape from the head toward the other end of the plate-shaped elastic body. 3. The angle formed by the pair of plate-shaped arms is:
3. The suspension according to claim 2, which is at most 180 degrees. 4. The suspension according to claim 2, wherein said driving means applies a voltage to each of said piezoelectric thin films so that said head makes a rotational movement. 5. The plate-shaped arm portion has a first surface, and the plate-shaped arm portion is arranged such that the first surface is substantially perpendicular to a recording / reproducing surface of the disk. The suspension according to claim 2. 6. The suspension according to claim 2, wherein the piezoelectric thin film includes a first piezoelectric thin film and a second piezoelectric thin film formed on a side of the head opposite to the first piezoelectric thin film. 7. The suspension according to claim 1, wherein the pair of plate-shaped arm portions are arranged substantially parallel from the head toward the other end of the plate-shaped elastic body. 8. The plate-shaped arm portion has a first surface, and the plate-shaped arm portion is arranged such that the first surface is substantially perpendicular to a recording / reproducing surface of the disk. The suspension according to claim 7. 9. The suspension according to claim 7, wherein the driving unit applies a voltage to each of the piezoelectric thin films so that the head performs a translational movement. 10. The suspension according to claim 7, wherein the piezoelectric thin film includes a first piezoelectric thin film and a second piezoelectric thin film formed on a side of the head opposite to the first piezoelectric thin film. 11. At least four piezoelectric thin films are formed on each of the plate-shaped arm portions, and the piezoelectric thin films are formed on a first piezoelectric thin film and on an opposite side of the head with respect to the first piezoelectric thin film. A second piezoelectric thin film, wherein each of the plate-shaped arm portions has a first surface and a second surface formed on a side opposite to the first surface; A third piezoelectric thin film formed on the first surface and a fourth piezoelectric thin film formed on the second surface, wherein the second piezoelectric thin film includes a fifth piezoelectric thin film formed on the first surface and the second surface And a sixth piezoelectric thin film formed on
The suspension according to claim 1. 12. The fourth piezoelectric thin film is formed behind a position where the third piezoelectric thin film is formed, and the sixth piezoelectric thin film is formed behind a position where the fifth piezoelectric thin film is formed. The suspension of claim 11, wherein 13. The suspension according to claim 1, wherein the piezoelectric thin film is arranged such that the head is slightly displaced by applying a voltage having the same polarity. 14. The piezoelectric thin film includes a first piezoelectric thin film and a second piezoelectric thin film formed on a side opposite to the head with respect to the first piezoelectric thin film. A first piezoelectric thin film formed on the first surface, and a second piezoelectric thin film formed on the second surface; and a second surface formed on the second surface opposite to the first surface. The suspension according to claim 13, wherein the first piezoelectric thin film and the second piezoelectric thin film are formed such that they do not exist on the front and back, respectively. 15. The piezoelectric thin film having a thickness of 1 μm or more and 10 μm or more.
The suspension according to claim 1, which is not more than mm. 16. The piezoelectric thin film includes PZT, PLT, Z
The suspension of claim 1, formed from any of nO and polyvinylidene fluoride (PVDF). 17. An information recording / reproducing apparatus for recording / reproducing information on / from a disk, comprising: a head for recording / reproducing at least data to / from the rotatably driven disk; and a slider having the head mounted thereon. A suspension having a plate-like elastic body having the slider mounted on one end, wherein the plate-like elastic body has a pair of plate-like arm portions, and each of the plate-like arm portions has at least two plate-like arm portions. A suspension on which a piezoelectric thin film is formed and further comprising driving means for applying a voltage in a thickness direction of the piezoelectric thin film so that the head is finely driven in a radial direction of the disk; An information recording / reproducing apparatus comprising: a main drive unit for performing dynamic positioning. 18. The information recording / reproducing apparatus, after performing coarse movement positioning of the head, applies a voltage in a thickness direction of the piezoelectric thin film of the plate-shaped arm portion to move the head in a radial direction of the disk. The information recording / reproducing apparatus according to claim 17, wherein the information recording / reproducing apparatus performs fine positioning by moving the information recording / reproducing apparatus. 19. The information recording / reproducing apparatus according to claim 17, wherein the pair of plate-shaped arm portions are arranged in a fan shape from the head toward the other end of the plate-shaped elastic body. 20. The information recording / reproducing apparatus according to claim 17, wherein the pair of plate-like arm portions are disposed substantially parallel from the head toward the other end of the plate-like elastic body. 21. The information recording / reproducing apparatus according to claim 20, wherein the driving means applies a voltage to each of the piezoelectric thin films so that the head performs a translational movement. 22. The piezoelectric thin film having a thickness of 1 μm or more and 10 μm or more.
The information recording / reproducing apparatus according to claim 17, wherein the distance is equal to or less than mm. 23. The piezoelectric thin film comprises PZT, PLT, Z
The information recording / reproducing apparatus according to claim 17, wherein the information recording / reproducing apparatus is formed of any of nO and polyvinylidene fluoride (PVDF). 24. A method for positioning an information recording / reproducing apparatus for recording or reproducing information on / from a disk, wherein the information recording / reproducing apparatus performs at least data recording or reproduction on the rotatably driven disk. A suspension having a head, a slider on which the head is mounted, and a plate-like elastic body having the slider mounted on one end, wherein the plate-like elastic body has a pair of plate-like arm portions; At least two piezoelectric thin films are formed on each of the arm-shaped portions, and a driving unit for applying a voltage in a thickness direction of each of the piezoelectric thin films is further provided so that the head is finely driven in a radial direction of the disk. A suspension; and main drive means for performing coarse movement positioning of the head with respect to the disk, and coarse movement of the head with respect to the disk. An information recording / reproducing apparatus comprising: a first step of performing positioning; and a second step of applying a voltage in a thickness direction of each of the piezoelectric thin films so that the head is finely driven in a radial direction of the disk. Positioning method. 25. The pair of plate-like arm portions includes a first arm and a second arm, and the piezoelectric thin film includes a first piezoelectric thin film, a second piezoelectric thin film formed on the first arm, and the second piezoelectric thin film. Third formed on two arms
A second piezoelectric thin film formed on a side opposite to the head with respect to the first piezoelectric thin film; and a fourth piezoelectric thin film formed with respect to the third piezoelectric thin film. The second step is formed on an opposite side of the head, and the second step is a step of applying a voltage of a first polarity to the first piezoelectric thin film and the fourth piezoelectric thin film; The method according to claim 24, further comprising: applying a voltage having a second polarity different from the first polarity to the piezoelectric thin film. 26. The positioning method for an information recording / reproducing apparatus according to claim 25, wherein the pair of plate-like arm portions are arranged in a sector shape from the head toward the other end of the plate-like elastic body. 27. The positioning of the information recording / reproducing apparatus according to claim 25, wherein the pair of plate-like arm portions are arranged substantially in parallel from the head toward the other end of the plate-like elastic body. Method. 28. The pair of plate-like arm portions includes a first arm and a second arm, wherein the first arm has a first surface and a second surface formed on a side opposite to the first surface. The second arm has a third surface and a fourth surface formed on the opposite side of the third surface, and the piezoelectric thin film is formed on the first surface of the first arm. A first piezoelectric thin film, a second piezoelectric thin film, and a third piezoelectric thin film and a fourth piezoelectric thin film formed on the second surface of the first arm.
A fifth piezoelectric thin film and a sixth piezoelectric thin film formed on the third surface of the second arm; a seventh piezoelectric thin film and an eighth piezoelectric thin film formed on the fourth surface of the second arm; A second piezoelectric thin film and the fourth piezoelectric thin film are formed on opposite sides of the head with respect to the first piezoelectric thin film and the third piezoelectric thin film, respectively; the sixth piezoelectric thin film and the eighth piezoelectric thin film; Is formed on the opposite side of the head with respect to each of the fifth piezoelectric thin film and the seventh piezoelectric thin film, and the second step is performed by the first piezoelectric thin film, the fourth piezoelectric thin film, and the sixth piezoelectric thin film. Applying a voltage of a first polarity to the piezoelectric thin film and the seventh piezoelectric thin film; and applying a voltage of the first polarity to the second piezoelectric thin film, the third piezoelectric thin film, the fifth piezoelectric thin film, and the eighth piezoelectric thin film. Applying a voltage having a second polarity different from the first polarity. The positioning method for an information recording / reproducing apparatus according to claim 24, wherein 29. The positioning method for an information recording / reproducing apparatus according to claim 24, wherein the second step includes a step of applying a voltage of a first polarity to all the piezoelectric thin films. 30. The piezoelectric thin film includes a first piezoelectric thin film and a second piezoelectric thin film formed on a side opposite to the head with respect to the first piezoelectric thin film. A first piezoelectric thin film formed on the first surface, and a second piezoelectric thin film formed on the second surface; and a second surface formed on the second surface opposite to the first surface. 30. The positioning method for an information recording / reproducing apparatus according to claim 29, wherein the first piezoelectric thin film and the second piezoelectric thin film are formed so as not to be present on both sides.