JP2001118230A - Fine positioning actuator, actuator for positioning thin film magnetic head element, and head suspension assembly provided with the actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fine positioning actuator high in impact resistance without obstructing its operation, an actuator for positioning a thin film magnetic head element and a head suspension assembly provided with the actuator. SOLUTION: In this actuator using piezoelectric effect for performing positioning by being fixed between an object to be positioned or a magnetic head slider and a supporting mechanism and by displacing the object or the head slider in the horizontal direction, a reinforcing member that has flexibility against the displacement in the direction of this actuator and that has rigidity against the displacement in the vertical direction is attached thereto.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an actuator for minutely positioning an object, an actuator for positioning a thin-film magnetic head element used in a magnetic disk drive, and a head suspension assembly provided with the actuator.

[0002]

2. Description of the Related Art In a magnetic disk drive, a magnetic head slider attached to the tip of a suspension of a head suspension assembly is levitated from the surface of a rotating magnetic disk, and in this state, a thin film mounted on the magnetic head slider is mounted. Recording to and / or reproduction from the magnetic disk is performed by the magnetic head element.

In recent years, with the increase in capacity and recording density of magnetic disk drives, the density in the disk radial direction (track width direction) has been increasing, and a conventional voice coil motor (hereinafter referred to as VCM) has been developed. ), It is becoming difficult to accurately adjust the position of the magnetic head.

As one of means for realizing precise positioning of a magnetic head, another actuator mechanism such as a small VCM, a piezoelectric element, or a MEMS (micro electromechanical system) is further provided on the magnetic head slider side than the conventional VCM. Mechanical system), etc.
This is a technique in which fine secondary positioning that cannot be followed by a CM is performed by a secondary actuator (for example, Japanese Patent Application Laid-Open Nos. 6-259905 and 6-309).
822, JP-A-8-180623).

Among the actuators of this type, the present applicant has proposed a piezoelectric element type actuator which is inserted between a magnetic head slider and a suspension to displace the magnetic head slider.

This actuator has a fixed portion fixed to the suspension, a movable portion fixed to the magnetic head slider, and a connection between the fixed portion and the movable portion.
It is mainly constituted by two mutually parallel displacement generating beam portions which expand and contract in accordance with an applied electric signal.

[0007]

However, since such an actuator is arranged in the vicinity of a magnetic head slider with little free space, it is required to reduce the size of the actuator itself and to provide a sufficient displacement. In order to ensure this, a structure is adopted in which the displacement generating beam portion is made narrow and the interval between the two displacement generating beam portions is made as small as possible.

The head suspension assembly must be assembled with a gap between the magnetic head slider and the actuator and between the actuator and the suspension so as not to hinder the movement of the actuator. However, providing such a gap increases the possibility that a large impact load is applied to the actuator. In particular, the piezoelectric element type actuator having the structure as described above not only has the piezoelectric material itself fragile, but also has a very thin structure in which the displacement generating beam portion has a very thin structure, so that an impact load is applied to this portion. It is a problem.

SUMMARY OF THE INVENTION Accordingly, the present invention is to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a micro-positioning actuator and a thin-film magnetic head element which have high impact resistance without obstructing the operation of the actuator. And a head suspension assembly provided with the actuator.

[0010]

According to the present invention, a piezoelectric phenomenon is used for positioning by fixing the object to be positioned and the support mechanism and displacing the object in the lateral direction. An actuator is provided, wherein the micro-positioning actuator is provided with a flexible reinforcing member for displacement in the direction of the actuator and a rigid reinforcing member for displacement in the longitudinal direction.

Further, according to the present invention, positioning is performed by fixing the thin-film magnetic head element between the magnetic head slider having at least one thin-film magnetic head element and the support mechanism and displacing the thin-film magnetic head element in the lateral direction. Actuator for positioning a thin film magnetic head element using a piezoelectric phenomenon, wherein a flexible member is attached to a lateral displacement of the actuator and a rigid reinforcing member is attached to a longitudinal displacement of the actuator. Is provided.

Furthermore, according to the present invention, at least one
A magnetic head slider having two thin film magnetic head elements, an actuator fixed to the magnetic head slider and utilizing a piezoelectric phenomenon for positioning by displacing the thin film magnetic head element in a lateral direction, and the actuator is fixed. There is provided a head suspension assembly including a support mechanism for supporting an actuator and a reinforcing member having flexibility for lateral displacement of the actuator and rigidity for longitudinal displacement.

A reinforcing member having flexibility for lateral displacement of the actuator and rigidity for longitudinal displacement is attached to the actuator. For this reason, since the actuator does not hinder the lateral movement and has rigidity in the vertical direction, the impact resistance is enhanced.

The actuator comprises a fixed portion, a movable portion,
The fixed part and the movable part are connected to each other, and are provided with two mutually parallel displacement generating beam parts that expand and contract in response to an electric signal, and the reinforcing member is parallel to a side surface of the two displacement generating beam parts. It preferably includes a thin metal strip having a surface and elasticity.

Further, the actuator has a fixed part, a movable part, and two mutually parallel displacement generating beam parts which connect the fixed part and the movable part and which expand and contract in accordance with an electric signal. Preferably, the reinforcing member includes an elastic member filled in a groove between the two displacement generating beam portions.

[0016]

FIG. 1 is a plan view of an entire head suspension assembly as viewed from the slider side according to an embodiment of the present invention. FIG. 2 is a flexure of an actuator and a magnetic head slider in the embodiment of FIG. FIG. 3 is an exploded perspective view showing an attachment structure to the actuator, FIG. 3 shows the structure of the actuator in the embodiment of FIG. 1, (A) is a plan view seen from the support mechanism side, (B) is a side view, (C) is a bottom view.

As shown in these figures, in the head suspension assembly, an actuator 11 for precisely positioning a magnetic head element is attached to the tip of a suspension 10, and a slider 12 having a magnetic head element is fixed to the actuator 11. It is composed.

As is well known, a magnetic disk drive is provided with a main actuator (VCM) for displacing a drive arm to which such a head suspension assembly is attached and moving the entire assembly. The actuator 11 is provided to enable a minute displacement that cannot be driven by such a main actuator.

The actuator 11 has a multilayer structure including a piezoelectric / electrostrictive material layer which expands and contracts by an inverse piezoelectric effect or an electrostrictive effect, as will be described later.
Are electrically connected to the suspension 10 electrically and mechanically. Its size is, for example, 1.25
magnetic head slider 1 mm × 1.0 mm × 0.3 mm
The size is almost equal to 2. In this embodiment, the position of the actuator 11
Considering the mechanical and electrical performance of the suspension 10
Are slightly shifted backward from the magnetic head slider 12.

In this embodiment, the actuator 11 and the magnetic head slider 12 are mounted on the surface of the suspension 10 facing the magnetic disk medium so as to face the surface of the magnetic disk medium. Although not shown, a head driving IC chip may be mounted in the middle of the suspension 10.

The suspension 10 includes the actuator 1
An elastic flexure 13 for supporting the slider 12 with a tongue 16 provided at one end through the flexure 1, a load beam 14 that supports and fixes the flexure 13 and also has an elasticity, It is mainly composed of a base plate 15 provided on the base.

The load beam 14 is connected to the actuator 11
The slider 12 has elasticity to press the slider 12 in the direction of the magnetic disk via the.

On the other hand, the flexure 13 is used for the load beam 1.
Soft tongue 1 pressed by dimples provided on 4
The tongue 16 has elasticity to flexibly support the slider 12 via the actuator 11.
As in the present embodiment, the flexure 13 and the load beam 1
In a suspension having a three-piece structure in which the component 4 is an independent component, the rigidity of the flexure 13 is lower than the rigidity of the load beam 14.

In this embodiment, the flexure 13 is made of a stainless steel plate (for example, SUS304T) having a thickness of about 25 μm.
A).

On the flexure 13, a flexible wiring member 17 including a plurality of lead conductors in a laminated thin film pattern is formed. That is, the wiring member 17 is a flexible printed circuit (Flexible Print Circuit).
It is formed by the same well-known patterning method as that for forming a printed circuit board on a thin metal plate as in the case of a circuit (a unit such as a unit, FPC). For example, a first insulating material layer made of a resin material such as polyimide having a thickness of about 5 μm, a patterned Cu layer (lead conductor layer) having a thickness of about 4 μm, and a first insulating material layer made of a resin material such as polyimide having a thickness of about 5 μm. 2 are formed by sequentially laminating two insulating material layers in this order from the flexure 13 side. However, in the portion of the connection pad for connecting to the magnetic head element and the external circuit, the Au layer is formed on the Cu layer, and the insulating material layer is not formed thereon.

In this embodiment, the wiring member 17 is
A first wiring member 17a including two lead conductors on one side connected to the magnetic head element and a total of four lead conductors on both sides, and a first wiring member 17a connected on two sides to the actuator 11 and including a total of four lead conductors on both sides. And two wiring members 17b.

One end of the lead conductor of the first wiring member 17a is connected to the connection pad 1 provided at the tip of the flexure 13.
8 is connected. The connection pad 18 is connected to the terminal electrode of the magnetic head slider 12 by gold bonding, wire bonding, stitch bonding, or the like. The other end of the lead conductor of the first wiring member 17a is connected to a connection pad 19 for connecting to an external circuit.

One end of the lead conductor of the second wiring member 17b is connected to a connection pad formed on the tongue 16 of the flexure 13, and this connection pad is connected to the actuator 1
1 terminal electrode. Second wiring member 17b
The other end of the lead conductor is connected to a connection pad 19 for connecting to an external circuit.

The load beam 14 is made of a stainless steel plate having a thickness of about 60 to 65 μm and having an elasticity, the width of which decreases toward the tip, and supports the flexure 13 over its entire length. However, the fixing between the flexure 13 and the load beam 14 is performed by pinpoint fixing by a plurality of welding points.

The base plate 15 is made of stainless steel or iron, and is fixed to the base of the load beam 14 by welding. By fixing the base plate 15 with the mounting portion 20, the suspension 1
0 is attached to a movable arm (not shown).
Note that the flexure 13 and the load beam 14 may not be separately provided, and a suspension having a two-piece structure of a base plate and a flexure-load beam may be used.

As shown in more detail in FIG. 2, the actuator 11 has a fixed portion 11a and a movable portion 11b, and further has two rod-shaped displacement generating beam portions 11c and 11d connecting these. The displacement generating beam sections 11c and 11d are provided with at least one piezoelectric / electrostrictive material layer having electrode layers on both sides, and are configured to generate expansion and contraction by applying a voltage to the electrode layers. . The piezoelectric / electrostrictive material layer is made of a piezoelectric / electrostrictive material that expands and contracts by an inverse piezoelectric effect or an electrostrictive effect. The fixing portion 11a has three terminal electrodes 11e to 11e connected to the above-described electrode layers.
g is formed.

In particular, in this embodiment, FIGS. 2 and 3 (A)
As shown in (C), the reinforcing members 32 and 3 are provided beside the displacement generating beam portions 11c and 11d of the actuator 11.
3 is attached. These reinforcing members 32 and 33
Has a surface parallel to the side surfaces of the displacement generating beam portions 11c and 11d and is made of a thin metal strip having elasticity. That is, both ends of the metal strip plate 32 are formed into the arc shape protruding in the lateral direction, and the displacement generating beam portions 11 c
Are bonded to the surfaces of the fixed portion 11a and the movable portion 11b on the side of the displacement generating beam portion, respectively, and both ends of the metal strip 33 are displaced so as to form an arc shape projecting in the lateral direction. The side of the generation beam portion 11d is bonded to the surface of the fixed portion 11a and the movable portion 11b on the side of the displacement generation beam portion, respectively. Thereby, the metal strip 32
And 33 have flexibility with respect to the displacement of the actuator 11 in the horizontal direction, and have rigidity with respect to the displacement of the actuator 11 in the vertical direction (direction in which an impact load is applied).

The metal strips 32 and 33 are made of an elastic thin metal strip such as a stainless steel sheet (SUS304), a phosphor bronze sheet, or a beryllium copper sheet. The metal strips 32 and 33 and the fixing part 1
An elastic adhesive such as, for example, a fluorine-based elastic resin or an epoxy-based elastic resin may be used for bonding to the 1a and the movable portion 11b.

As shown in FIG. 2, the upper surface of the fixing portion 11a of the actuator 11 is adhered to the tongue 16 of the flexure 13 with an adhesive. In addition, as a method for fixing the actuator 11, the terminal electrodes 11e to 11g provided on the fixing portion 11a of the actuator 11 may be soldered to connection pads formed on the tongue 16 of the flexure 13, or The provided terminal electrodes 11e to 11g may be bonded to connection pads formed on the tongue 16 of the flexure 13 using a conductive adhesive. The movable portion 11b of the actuator 11 is fixed to a predetermined portion 12a on the rear end side (the formation end side of the magnetic head element 12b) of the magnetic head slider 12 by bonding its lower surface with an adhesive.

As described above, one ends of the displacement generating beam portions 11c and 11d are connected to the flexure 13 via the fixed portion 11a.
, And the other ends of the displacement generating beam portions 11c and 11d are connected to the slider 12 via the movable portion 11b. Further, the reinforcing members 32 and 33 have flexibility with respect to the movement in the lateral direction. Therefore, the displacement generating beam unit 1
The slider 12 is displaced in the horizontal direction by the expansion and contraction of 1c and 11d, and the magnetic head element is displaced in an arc shape so as to intersect the recording track of the magnetic disk.

Hereinafter, the structure of the actuator 11 will be described in more detail.

When the piezoelectric / electrostrictive material layers in the displacement generating beam portions 11c and 11d are made of a so-called piezoelectric material such as PZT, the piezoelectric / electrostrictive material layers usually have polarization for improving the displacement performance. Processing has been applied. The polarization direction by this polarization processing is the thickness direction of the actuator 11. When the direction of the electric field when a voltage is applied to the electrode layer matches the polarization direction, the piezoelectric / electrostrictive material layer between the two electrodes expands in the thickness direction (piezoelectric longitudinal effect) and contracts in the in-plane direction. (Piezoelectric lateral effect). On the other hand, when the direction of the electric field is opposite to the polarization direction, the piezoelectric / electrostrictive material layer contracts in its thickness direction (piezoelectric longitudinal effect) and elongates in its in-plane direction (piezoelectric transverse effect). Then, when a voltage causing contraction is alternately applied to one of the displacement generating beam portions and the other displacement generating beam portion, the ratio of the length of one displacement generating beam portion to the length of the other displacement generating beam portion is increased. As a result, both the displacement generating beam portions bend in the same direction in the plane of the actuator 11. As described above, the reinforcing member 3
2 and 33 are flexible with respect to the movement in the lateral direction, and the bending causes the movable portion 11b to move relative to the fixed portion 11a with the position indicated by the arrow 21 in FIG. Swings in the lateral direction shown in FIG. This swing
The movable portion 11b is a displacement that draws an arc-shaped trajectory in a direction substantially perpendicular to the direction of expansion and contraction of the displacement generating beam portions 11c and 11d, and the swing direction exists in the plane of the actuator. Therefore, the magnetic head element also swings along an arc-shaped trajectory. At this time, since the direction of the voltage is the same as that of the polarization, there is no fear of the polarization decay, which is preferable. Even if the voltage applied alternately to both the displacement generating beam portions causes the displacement generating beam portions to extend, the same swing occurs.

The actuator 11 may simultaneously apply voltages that cause opposite displacements to both displacement generating beam portions. That is, an alternating voltage may be simultaneously applied to one displacement generating beam portion and the other displacement generating beam portion such that when one expands, the other contracts, and when one contracts, the other expands. The movable part 11b at this time
Is centered on the position when no voltage is applied. In this case, the amplitude of the swing when the drive voltage is the same is about twice as large as when the voltage is applied alternately. However, in this case, the displacement generating beam portion is extended on one side of the swing, and the driving voltage at this time is opposite to the direction of polarization. Therefore, when the applied voltage is high or when the voltage is continuously applied, the polarization of the piezoelectric / electrostrictive material may be attenuated. Therefore, by applying a constant DC bias voltage in the same direction as the polarization and superimposing the alternating voltage on the bias voltage as the drive voltage, the direction of the drive voltage may be opposite to the direction of the polarization. Not to be. In this case, the swing is centered on the position when only the bias voltage is applied.

The actuator 11 is formed by forming holes and cutouts in a plate-like body made of a piezoelectric / electrostrictive material having an electrode layer provided at a predetermined position, so that the displacement generating beam sections 11c and 1c
1d, a fixed portion 11a and a movable portion 11b are integrally formed. Therefore, the rigidity and dimensional accuracy of the actuator can be increased, and there is no fear that an assembly error occurs. Further, since no adhesive is used for manufacturing the actuator itself, there is no adhesive layer in a portion where stress is generated by deformation of the displacement generating beam portion. Therefore, problems such as transmission loss due to the adhesive layer and aging of the adhesive strength do not occur.

The term "piezoelectric / electrostrictive material" means a material which expands and contracts by an inverse piezoelectric effect or an electrostrictive effect. The piezoelectric / electrostrictive material may be any material that can be applied to the displacement generating beam portion of the actuator as described above.
Because of high rigidity, PZT [Pb (Zr, T
i) O ₃ ], PT (PbTiO ₃ ), PLZT [(P
b, La) (Zr, Ti) O ₃ ], and barium titanate (BaTiO ₃ ) are preferred.

The reinforcing members 32 and 33 are
Since the actuator 11 has flexibility with respect to the lateral movement, the movement of the actuator 11 in that direction is not hindered. Further, since the reinforcing members 32 and 33 have rigidity in the vertical movement, the resistance to the impact load applied to the actuator 11 in this direction is increased.

FIGS. 4A and 4B show the structure of an actuator according to another embodiment of the present invention. FIG. 4A is a plan view seen from the support mechanism side, FIG. 4B is a side view, and FIG. 4C is a bottom view. .

As shown in FIG.
Has a fixed portion 41a and a movable portion 41b, and further has two rod-shaped displacement generating beam portions 41c and 41d connecting these. Displacement generating beam portions 41c and 41d
Is provided with at least one piezoelectric / electrostrictive material layer having an electrode layer on both sides, and is configured to expand and contract by applying a voltage to the electrode layer. The piezoelectric / electrostrictive material layer is made of a piezoelectric / electrostrictive material that expands and contracts by an inverse piezoelectric effect or an electrostrictive effect. The fixed portion 41a has three terminal electrodes 41e to 41g connected to the above-described electrode layers.

In this embodiment, in particular, the actuator 4
Reinforcing members 42 and 43 are attached to the side of the one displacement generating beam portions 41c and 41d. These reinforcing members 42 and 43 have surfaces parallel to the side surfaces of the displacement generating beam portions 41c and 41d, and are formed of thin metal strips having elasticity. That is, both ends of the metal strip 42 are adhered to the side surfaces of the fixed part 41a and the movable part 41b on the side of the displacement generating beam part 41c so that a part of the metal strip 42 becomes a corrugated shape that is concave in the horizontal direction. In addition, the metal strip 43 is bonded to the side surfaces of the fixed part 41a and the movable part 41b on both sides of the displacement generating beam part 41d so that a part of the metal strip 43 has a corrugated shape that is partially recessed in the lateral direction. Have been. As a result, the metal strips 42 and 43 have flexibility in the displacement of the actuator 41 in the horizontal direction, and have rigidity in the displacement of the actuator 41 in the vertical direction (direction in which an impact load is applied).

The metal strips 42 and 43 are made of a thin metal strip having elasticity such as a stainless steel sheet (SUS304), a phosphor bronze sheet, or a beryllium copper sheet. The metal strips 42 and 43 and the fixing part 4
An elastic adhesive such as, for example, a fluorine-based elastic resin or an epoxy-based elastic resin may be used for bonding to the 1a and the movable portion 41b.

The reinforcing members 42 and 43 are
Since the actuator 41 is flexible with respect to the lateral movement, the movement of the actuator 41 in that direction is not hindered. Further, since the reinforcing members 42 and 43 have rigidity in the movement in the vertical direction, the resistance to the impact load applied to the actuator 41 in this direction is increased.

The other configuration, operation and effect of this embodiment are completely the same as those of the embodiment of FIG.

FIGS. 5A and 5B show the structure of an actuator according to still another embodiment of the present invention. FIG. 5A is a plan view seen from the support mechanism side, FIG. 5B is a side view, and FIG. is there.

As shown in FIG.
Has a fixed portion 51a and a movable portion 51b, and further has two rod-shaped displacement generating beam portions 51c and 51d connecting these. Displacement generating beam portions 51c and 51d
Is provided with at least one piezoelectric / electrostrictive material layer having an electrode layer on both sides, and is configured to expand and contract by applying a voltage to the electrode layer. The piezoelectric / electrostrictive material layer is made of a piezoelectric / electrostrictive material that expands and contracts by an inverse piezoelectric effect or an electrostrictive effect. The fixed portion 51a has three terminal electrodes 51e to 51g connected to the above-described electrode layers.

In this embodiment, in particular, the actuator 5
An elastic member such as a fluorine-based elastic resin or an epoxy-based elastic resin is filled as a reinforcing member 54 in the groove between the two displacement generating beam portions 51c and 51d. Since the groove between the two displacement generating beam portions 51c and 51d has a narrow width and a deep shape, the elastic member 54 has flexibility in lateral displacement of the actuator 51, and has a vertical The displacement in the direction (direction in which an impact load is applied) has some rigidity.

Since the reinforcing member 54 is flexible with respect to the lateral movement of the actuator 51, the movement of the actuator 51 in that direction is not hindered. Further, since the reinforcing member 54 has a certain degree of rigidity in the movement in the vertical direction, the resistance to the impact load applied to the actuator 51 in this direction is increased.

The other configuration, operation and effect of this embodiment are completely the same as those of the embodiment of FIG.

FIGS. 6A and 6B show the structure of an actuator according to still another embodiment of the present invention. FIG. 6A is a plan view seen from the support mechanism side, FIG. 6B is a side view, and FIG. It is.

As shown in FIG.
Has a fixed portion 61a and a movable portion 61b, and further has two rod-shaped displacement generating beam portions 61c and 61d connecting these. Displacement generating beam portions 61c and 61d
Is provided with at least one piezoelectric / electrostrictive material layer having an electrode layer on both sides, and is configured to expand and contract by applying a voltage to the electrode layer. The piezoelectric / electrostrictive material layer is made of a piezoelectric / electrostrictive material that expands and contracts by an inverse piezoelectric effect or an electrostrictive effect. The fixed portion 61a is formed with three terminal electrodes 61e to 61g connected to the above-described electrode layers.

In this embodiment, in particular, the actuator 6
Reinforcing members 62 and 63 are attached to the side of the one displacement generating beam portions 61c and 61d. These reinforcing members 62 and 63 have surfaces parallel to the side surfaces of the displacement generating beam portions 61c and 61d, and are made of a thin metal strip having elasticity. That is, the metal strip 62 has the fixed portion 61a and the movable portion 6 on both sides of the displacement generating beam portion 61c so that the metal strip 62 has an arc shape protruding in the lateral direction.
1b, and the metal strip 63 has fixed portions at both sides of the displacement generating beam portion 61d so that the metal strip 63 has an arc shape protruding in the lateral direction. 61a and the movable portion 61b are bonded to the surfaces on the displacement generating beam portion side, respectively. This allows
The metal strips 62 and 63 have flexibility in the displacement of the actuator 61 in the horizontal direction, and have rigidity in the displacement of the actuator 61 in the vertical direction (direction in which an impact load is applied).

In this embodiment, the actuator 6
The groove between the two displacement generating beam portions 61c and 61d is filled with an elastic member such as a fluorine-based elastic resin or an epoxy-based elastic resin as the reinforcing member 64. Since the groove between the two displacement generating beam portions 61c and 61d has a narrow width and a deep shape, the elastic member 64 has flexibility in lateral displacement of the actuator 61, and has a vertical The displacement in the direction (direction in which an impact load is applied) has some rigidity.

Each of the metal strips 62 and 63 is made of an elastic thin metal strip such as a stainless steel sheet (SUS304), a phosphor bronze sheet, or a beryllium copper sheet. The metal strips 62 and 63 may be bonded to the fixed portion 61a and the movable portion 61b using an elastic adhesive such as a fluorine-based elastic resin or an epoxy-based elastic resin.

The reinforcing members 62 and 63 and the reinforcing member 6
Since the actuator 4 is flexible with respect to the lateral movement of the actuator 61, the movement of the actuator 61 in that direction is not hindered. Further, the reinforcing members 62 and 6
Third, since the reinforcing member 64 has rigidity in the movement in the vertical direction, the resistance to the impact load applied to the actuator 61 in this direction is increased.

The other configuration, operation and effect of this embodiment are completely the same as those of the embodiment of FIG.

FIGS. 7A and 7B show the structure of an actuator according to still another embodiment of the present invention. FIG. 7A is a plan view seen from the support mechanism side, FIG. 7B is a side view, and FIG. is there.

As shown in FIG.
Has a fixed portion 71a and a movable portion 71b, and further has two rod-shaped displacement generating beam portions 71c and 71d connecting these. Displacement generating beam portions 71c and 71d
Is provided with at least one piezoelectric / electrostrictive material layer having an electrode layer on both sides, and is configured to expand and contract by applying a voltage to the electrode layer. The piezoelectric / electrostrictive material layer is made of a piezoelectric / electrostrictive material that expands and contracts by an inverse piezoelectric effect or an electrostrictive effect. The fixed portion 71a has three terminal electrodes 71e to 71g connected to the above-described electrode layers.

In this embodiment, in particular, the actuator 7
Reinforcing members 72 and 73 are attached to the side of the one displacement generating beam portions 71c and 71d. These reinforcing members 72 and 73 have surfaces parallel to the side surfaces of the displacement generating beam portions 71c and 71d, and are made of a thin metal strip having elasticity. That is, both ends of the metal band plate 72 are adhered to the side surfaces of the fixed portion 71a and the movable portion 71b on the side of the displacement generating beam portion 71c so that a part of the metal band plate 72 has a corrugated shape depressed in the horizontal direction. The metal strip 73 has both ends bonded to the sides of the fixed part 71a and the movable part 71b on the sides of the displacement generating beam part 71d so that a part of the metal strip 73 is formed into a corrugated shape that is concave in the lateral direction. Have been. Accordingly, the metal strips 72 and 73 have flexibility in the displacement of the actuator 71 in the horizontal direction, and have rigidity in the displacement of the actuator 71 in the vertical direction (direction in which an impact load is applied).

In this embodiment, the actuator 7
The groove between the two displacement generating beam portions 71c and 71d is filled with an elastic member such as a fluorine-based elastic resin or an epoxy-based elastic resin as the reinforcing member 74. Since the groove between the two displacement generating beam portions 71c and 71d has a narrow width and a deep shape, the elastic member 74 has flexibility for lateral displacement of the actuator 71, and The displacement in the direction (direction in which an impact load is applied) has some rigidity.

The metal strips 72 and 73 are made of a thin metal strip having elasticity such as a stainless steel sheet (SUS304), a phosphor bronze sheet, or a beryllium copper sheet. The metal strips 72 and 73 may be bonded to the fixed portion 71a and the movable portion 71b using an elastic adhesive such as a fluorine-based elastic resin or an epoxy-based elastic resin.

The reinforcing members 72 and 73 and the reinforcing member 7
Since the actuator 4 has flexibility with respect to the lateral movement of the actuator 71, the movement of the actuator 71 in that direction is not hindered. Also, the reinforcing members 72 and 7
Third, since the reinforcing member 74 has rigidity in the vertical movement, the resistance of the actuator 71 to an impact load applied in this direction is increased.

The other configurations, functions and effects of this embodiment are exactly the same as those of the embodiment of FIG.

In the above-described embodiment, the metal strip is used as the reinforcing member to be externally attached. However, the reinforcing member of the present invention is not limited to this, and is made of a material having the same elasticity as metal. A strip can be used.
In addition, a member having flexibility in one direction and rigidity in a direction perpendicular to the one direction can be used without being limited to the band plate. Further, the shape is not limited to the shape of the above-described embodiment.

Although the present invention has been described above using the head suspension assembly provided with the actuator for positioning the thin-film magnetic head element, the present invention is not limited to such an actuator. The present invention is also applicable to an actuator that minutely positions an object other than the above.

The embodiments described above are merely examples of the present invention, and do not limit the present invention. The present invention can be embodied in other various modifications and alterations. Therefore, the scope of the present invention is defined only by the appended claims and their equivalents.

[0070]

According to the present invention, as described in detail above, the actuator has flexibility in lateral displacement,
A reinforcing member having rigidity for vertical displacement is attached to the actuator. For this reason, since the actuator does not hinder the lateral movement and has rigidity in the vertical direction, the impact resistance is enhanced.

[Brief description of the drawings]

FIG. 1 is a plan view of an entire head suspension assembly as viewed from a slider side according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view showing a structure for attaching an actuator and a magnetic head slider to a flexure in the embodiment of FIG. 1;

3A and 3B show a structure of an actuator in the embodiment of FIG. 1; FIG. 3A is a plan view seen from a support mechanism side;
(B) is a side view, and (C) is a bottom view.

4A and 4B show a structure of an actuator according to another embodiment of the present invention, wherein FIG. 4A is a plan view seen from a support mechanism side, FIG. 4B is a side view, and FIG. 4C is a bottom view.

5A and 5B show a structure of an actuator according to still another embodiment of the present invention, wherein FIG. 5A is a plan view seen from a support mechanism side, FIG. 5B is a side view, and FIG. 5C is a bottom view.

6A and 6B show a structure of an actuator according to still another embodiment of the present invention, wherein FIG. 6A is a plan view as viewed from a support mechanism side, FIG. 6B is a side view, and FIG. 6C is a bottom view. .

7A and 7B show a structure of an actuator according to still another embodiment of the present invention, wherein FIG. 7A is a plan view as viewed from a support mechanism side, FIG. 7B is a side view, and FIG. 7C is a bottom view.

[Explanation of symbols]

10 Suspension 11, 41, 51, 61, 71 Actuator 11a, 41a, 51a, 61a, 71a Fixed part 11b, 41b, 51b, 61b, 71b Movable part 11c, 11d, 41c, 41d, 51c, 51d, 6
1c, 61d, 71c, 71d Displacement generating beam portions 11e, 11f, 11g, 41e, 41f, 41g, 5
1e, 51f, 51g, 61e, 61f, 61g, 71
e, 71f, 71g Terminal electrode 12 Magnetic head slider 13 Flexure 14 Load beam 15 Base plate 16 Tongue 17 Wiring member 17a First wiring member 17b Second wiring member 18, 19 Connection pad 20 Mounting part 32, 33, 42, 43, 54, 62, 63, 64, 7
2, 73, 74 reinforcing member

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ken Wada, 1-13-1 Nihonbashi, Chuo-ku, Tokyo Inside TDK Corporation (72) Inventor Mitsuyoshi Kawai 1-13-1 Nihonbashi, Chuo-ku, Tokyo Inside DK Co., Ltd. (72) Inventor Keiichi Soeno 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDK Incorporated (72) Inventor Norio Ota 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDK F term (reference) 5D033 BB14 BB51 5D042 LA01 MA15 5D059 AA01 BA01 CA26 DA26 DA28 DA30 EA02 5D096 NN03 NN07

Claims (9)

[Claims] 1. An actuator using a piezoelectric phenomenon for positioning by fixing the object to be positioned and a support mechanism and displacing the object in a lateral direction, wherein the actuator uses the piezoelectric phenomenon. A micro-positioning actuator characterized in that a flexible reinforcing member is attached to a lateral displacement and a rigid reinforcing member is attached to a vertical displacement. 2. The actuator according to claim 1, wherein the actuator includes a fixed portion, a movable portion, and two mutually parallel displacement generating beam portions that connect the fixed portion and the movable portion and expand and contract in response to an electric signal. 2. The actuator according to claim 1, wherein the reinforcing member includes a thin metal strip having a surface parallel to a side surface of the two displacement generating beam portions and having elasticity. 3. . 3. The actuator includes a fixed part, a movable part, and two mutually parallel displacement generating beam parts that connect the fixed part and the movable part and expand and contract in response to an electric signal. 3. The actuator according to claim 1, wherein the reinforcing member includes an elastic member filled in a groove between the two displacement generating beam portions. 4. A piezoelectric phenomenon for positioning between a magnetic head slider having at least one thin-film magnetic head element and a support mechanism and displacing the thin-film magnetic head element in a lateral direction. Characterized in that a flexible reinforcing member is attached to the lateral displacement of the actuator and a rigid reinforcing member is attached to the longitudinal displacement of the actuator. Actuator. 5. The actuator includes a fixed part, a movable part, and two mutually parallel displacement generating beam parts that connect the fixed part and the movable part and expand and contract in response to an electric signal. 5. The actuator according to claim 4, wherein the reinforcing member includes a thin metal strip having a surface parallel to a side surface of the two displacement generating beam portions and having elasticity. 6. . 6. The actuator includes a fixed part, a movable part, and two mutually parallel displacement generating beam parts that connect the fixed part and the movable part and expand and contract in response to an electric signal. The actuator according to claim 4, wherein the reinforcing member includes an elastic member filled in a groove between the two displacement generating beam portions. 7. A magnetic head slider having at least one thin-film magnetic head element, and an actuator that is fixed to the magnetic head slider and uses a piezoelectric phenomenon to perform positioning by displacing the thin-film magnetic head element in a lateral direction. And a support mechanism to which the actuator is fixed and for supporting the actuator, and a reinforcing member having flexibility for the lateral displacement of the actuator and rigidity for the vertical displacement. A head suspension assembly comprising: 8. The actuator includes a fixed part, a movable part, and two mutually parallel displacement generating beam parts that connect the fixed part and the movable part and expand and contract in response to an electric signal. 8. The head according to claim 7, wherein the reinforcing member includes a thin metal strip having a surface parallel to a side surface of the two displacement generating beam portions and having elasticity. Suspension assembly. 9. The actuator according to claim 1, wherein the actuator includes a fixed part, a movable part, and two mutually parallel displacement generating beam parts that connect the fixed part and the movable part and expand and contract in response to an electric signal. 9. The head suspension assembly according to claim 7, wherein the reinforcing member includes an elastic member filled in a groove between the two displacement generating beam portions.