JP2001332041A - Thin film piezoelectric actuator for disk device and method of manufacturing the same - Google Patents

Abstract

(57) Abstract: A thin film piezoelectric actuator can be easily manufactured, and the reliability of power supply to a thin film piezoelectric element is improved. SOLUTION: In a thin film piezoelectric actuator 5A for a disk device for displacing at least a head (not shown) for reproducing data on a rotationally driven disk, a surface of a copper plate 8 constituting a thin film piezoelectric substrate 1 is provided. Then, the thin film piezoelectric element 4A is directly bonded in an electrically conductive state by the adhesive 10. The surface of the copper plate 8 to which the thin-film piezoelectric element 4A is bonded is provided with an uneven shape having a height difference of 0.4 μm or more. The surface unevenness of the copper plate 8 is provided by a sand blast process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head support mechanism used for recording and reproducing information on and from a disk of a disk device used as a storage device of a computer, and more particularly to information on a disk provided on the disk device. The present invention relates to a thin-film piezoelectric actuator suitably used as an optimal head support mechanism for increasing the recording density of a recording medium.

[0002]

2. Description of the Related Art Conventionally, the recording density of data on a disk provided in a disk device has tended to be increased. In particular, the recording density of data on a magnetic disk provided in a magnetic disk device has been increasing. The density is increasing with each passing day. A magnetic head used for recording and reproducing data on and from a magnetic disk is usually mounted on a slider, and the slider on which the magnetic head is mounted is supported by a head support mechanism provided in the magnetic disk device. . The head support mechanism has a head actuator arm to which a slider is attached, and the head actuator arm is rotated by a voice coil motor (VCM). By controlling the VCM, the magnetic head mounted on the slider is positioned at an arbitrary position on the magnetic disk.

In order to record data on a magnetic disk at a higher density, it is necessary to position the magnetic head with respect to the magnetic disk with higher precision. However, the configuration in which the magnetic head is positioned by rotating the head actuator arm in the VCM has a problem that the magnetic head cannot be positioned with higher accuracy. In order to solve this problem, various proposals have been made for a technique for positioning a magnetic head with respect to a predetermined track of a magnetic disk with high accuracy. In particular, in recent years, a thin film piezoelectric actuator that displaces a magnetic head in a minute range by using a piezoelectric material having a property of expanding and contracting by applying a voltage has been proposed. Hereinafter, an example of a suspension equipped with a thin film piezoelectric actuator will be described.

FIG. 3 is a perspective view showing the overall structure of an example of a suspension on which a thin film piezoelectric actuator is mounted.
FIG. 4 is an exploded perspective view showing the suspension 25 of FIG.

A suspension 25 on which the thin film piezoelectric actuators 5A and 5B are mounted has a slider holding plate 2 for holding a slider (not shown) on which a magnetic head is mounted, and the slider and the slider holding plate 2 are mounted on the tip. A load beam 6 rotatably supported, a thin-film piezoelectric substrate 1 as an operation substrate for supporting a slider on the distal end on the load beam 6 and rotating the slider, and a thin-film piezoelectric substrate 1 , A first wiring pattern 20 provided from the front end side to the base end side of the thin film piezoelectric substrate 1, and a second wiring provided along the first wiring pattern 20. And a pattern 21.

The load beam 6 has a square base portion 6A, a neck portion 6C extending from the base portion 6A toward the distal end, and a taper shape further extending from the neck portion 6C toward the distal end. The slider holding plate 2 is mounted on a mounting portion 6G provided at the tip of the beam portion 6E.

[0007] A square base plate 7 corresponding to the base end 6A is attached to the lower surface of the base end 6A of the load beam 6 by beam welding or the like. The base plate 7 is pivotally attached to a head actuator (not shown), and a load beam 6 is provided.
Is driven to rotate around the base end 6A by a head actuator such that the front end of the beam portion 6E moves in a substantially radial direction of a magnetic disk (not shown). Therefore, the slider is moved along a substantially radial direction of the magnetic disk by the turning drive of the load beam 6 in this manner.

A circular opening 6B is provided at the center of the base end 6A of the load beam 6, and a triangular opening 6D is provided at the center of the neck 6C. Both sides of the triangular opening 6D in the neck 6C are leaf springs 6I and 6J, respectively. The mounting portion 6G is elastically displaced in a direction perpendicular to the surface of the magnetic disk by the leaf spring portions 6I and 6J, and the mounting portion 6G is elastically displaced by the mounting portion 6G. , A load is applied to the slider provided in the slider.

The mounting portion 6G is integrally formed with dimples 6H projecting hemispherically toward the upper surface. The mounting portion 6G is further provided with a pair of regulating portions 6F, 6F extending linearly from the distal end of the mounting portion 6G toward the base end side. Each restricting portion 6F extends toward the base end with an appropriate gap above the upper surface of the mounting portion 6G.

A slider is held on the slider holding plate 2 mounted on the mounting portion 6G via the tip of the thin film piezoelectric substrate 1. In the center of the slider holding plate 2 at the base end side, a protrusion 2A protruding in a semicircular shape toward the base end side.
Is provided.

The protrusion 2A of the slider holding plate 2 is attached to a dimple 6H provided on the mounting portion 6G of the load beam 6.
The slider holding plate 2 is supported by point contact from below, and both ends of the slider holding plate 2 are regulated with a suitable minute interval from each regulating portion 6F provided on the mounting portion 6G. Thus, the slider holding plate 2 is supported so as to be able to rotate in all directions at a small displacement angle together with the slider provided thereon.

The thin-film piezoelectric substrate 1 has a long plate shape extending from the distal end to the proximal end of the load beam 6.
It is arranged along the surface of the magnetic disk. A slider attaching portion 1C disposed on the slider holding plate 2 is provided at the tip of the thin film piezoelectric substrate 1, and a slider is attached on the slider attaching portion 1C. The side edge on the base end side of the slider holding plate 2 is substantially aligned with the side edge on the base end side of the slider attachment portion 1C.

The substrate holding portion 1D of the thin film piezoelectric substrate 1 has a leaf spring portion 6I of the load beam 6 and a base end portion 6A.
The wiring portion 1G disposed on one side of the wiring portion 1G is provided continuously, and the terminal holding portion 1H is provided at the base end of the wiring portion 1G.

FIG. 5 is a plan view of the tip of the thin-film piezoelectric substrate 1 arranged on the load beam 6, and FIG.
FIG. 4 is a schematic cross-sectional view taken along line -A ′.

On the base end side of the slider attaching portion 1C,
A pair of support portions 1A and 1B respectively forming a pair of thin film piezoelectric actuators 5A and 5B that expand and contract in different phases in the horizontal direction with respect to the surface of the magnetic disk.
Respectively, via the elastic hinge portions 1E and 1F,
It is provided integrally. The base ends of the support portions 1A and 1B are respectively continuous with the rectangular substrate holding portion 1D. The substrate holding section 1D is fixed to the upper surface of the beam section 6E of the load beam 6 via the stainless steel plate 3.

The pair of supports 1A and 1B are parallel at a predetermined interval. A pair of elastic hinges 1E
And 1F are formed by reducing the width dimensions of the tip portions of the support portions 1A and 1B, respectively.
The slider attaching portion 1C can be rotated in all directions at a small displacement angle by the elastic hinge portions 1E and 1F. Therefore, the slider and the slider attaching portion disposed on the slider attaching portion 1C are provided. The slider holding plate 2 disposed below the attachment portion 1C can rotate in all directions at a small displacement angle.

Each of the supporting portions 1A and 1B is formed by covering a 3 μm thick copper plate 8 with a polyimide resin 9 as an insulator, and the thin film piezoelectric elements 4A and 4A are provided on the upper surfaces of the supporting portions 1A and 1B. 4B is adhesive 1
0 is attached in a laminated state, and is integrated with each of the support portions 1A and 1B. The supporting portions 1A and 1B of the thin-film piezoelectric substrate 1 are thin-film piezoelectric elements 4A and 4B
Together, they constitute the thin film piezoelectric actuators 5A and 5B, respectively. Note that, instead of the copper plate 8, a metal plate such as stainless steel may be used.

The thin film piezoelectric substrate 1 is provided with a first wiring pattern 20 for transferring a recording / reproducing signal to a magnetic head (not shown). The first wiring pattern 20 has four wiring lines 20A to 20D. One end of each of the wiring lines 20A to 20D is
Four slider connection terminals 22A, 22B, 22 provided on slider attachment portion 1C of thin film piezoelectric substrate 1
C and 22D. Then, the four slider connection terminals 22A, 22B, 22C, 22D
Is a slider attaching portion 1 on the thin film piezoelectric substrate 1.
Each terminal is connected to each terminal (not shown) provided on the slider on the upper surface of C.

The pair of wiring lines 20A and 20B of the first wiring pattern 20 connected to the slider connection terminals 22A and 22B are respectively formed on the thin film piezoelectric member 1A provided on one support portion 1A of the thin film piezoelectric substrate 1. The body element 4A is drawn to the base end side through the side portion and the substrate holding portion 1D. Slider connection terminals 22C and 2
Another pair of wiring lines 20C respectively connected to 2D
And 20D are the other support portions 1 of the thin film piezoelectric substrate 1.
It passes through the thin film piezoelectric element 4B provided on B and the substrate holding portion 1D, and is drawn out to the base end side.

The four wiring lines 20A to 20D drawn to the base end side of the thin film piezoelectric substrate 1 pass through the wiring portion 1G, and the external connection terminals 24C to 24C provided on the terminal holding portion 1H. 24F, respectively.

The four wiring lines 20A to 20D
Is a polyimide resin 9 for the thin film piezoelectric substrate 1.
Has been fixed by.

The second wiring pattern 21 is used for driving two thin film piezoelectric elements 4A and 4B arranged on the upper surface of the thin film piezoelectric substrate 1. Second wiring pattern 21
Is composed of four wiring lines 21A to 21D. A pair of thin film piezoelectric element connection terminals 23A, 23B, 23C, and 23D are exposed from the polyimide resin 9 on the base end side of the support portions 1A and 1B in the thin film piezoelectric substrate 1, respectively. Is provided. One end of each of the wiring lines 21A to 21D is connected to four thin film piezoelectric element connecting terminals 23A, 23B, 23C, 23D on the base end sides of the pair of support plates 1A and 1B, respectively. .

Wiring line 21 of second wiring pattern 21
A to 21D pass through the substrate holding portion 1D of the thin film piezoelectric substrate 1 and are respectively drawn to the base end side.

The four wiring lines 21A to 21D drawn to the base end side of the thin film piezoelectric substrate 1 pass through the wiring portion 1G and are connected to the external connection terminals 24A to 24A on the terminal holding portion 1H.
24B, 24G to 24H, respectively.

These four wiring lines 20A to 20D
Also, for the thin film piezoelectric substrate 1, a polyimide resin 9
Has been fixed by.

FIG. 7 is a cross-sectional view taken along the line AA 'of FIG. 5, and shows one thin film piezoelectric actuator 5A in detail.

The thin-film piezoelectric element 4A has a lead zirconate titanate (PZT) thin film 13, which is a piezoelectric material, and a voltage is applied between its upper and lower surfaces to correspond to the voltage. The elastic deformation occurs in the longitudinal direction, and the elastic deformation generated in the thin film piezoelectric element 4A causes the thin film piezoelectric actuator 5A to expand and contract in the longitudinal direction. Thereby, the slider attaching portion 1C
Is rotated in all directions at a small displacement angle.

On the upper and lower surfaces of the lead zirconate titanate (PZT) thin film 13 of the thin film piezoelectric element 4A, an upper electrode 12 and a lower electrode 14 made of platinum are provided, respectively. , Lower electrode 1
A lead wire 18 electrically connected to 4 is drawn out to the side of the thin film piezoelectric element 4A. The other thin film piezoelectric actuator 5B has a similar structure.

The pair of thin film piezoelectric element connecting terminals 23A and 23B are mounted in a conductive state on the upper electrode 12 and the lead 18 of the thin film piezoelectric element 4A, respectively. Similarly, a pair of thin film piezoelectric element connection terminals 23C
And 23D are attached to the upper surface electrode 12 and the lead wire 18 of the thin film piezoelectric element 4B in a state of being in electrical contact with each other.

The thin film piezoelectric actuators 5A and 5
The operation of B will be described with reference to FIGS.

The thin film piezoelectric elements 4A and 4B are arranged in the longitudinal direction of the thin film piezoelectric elements 4A and 4B in accordance with the voltage applied to the upper electrode 12 and the lead wire 18 of each of the thin film piezoelectric elements 4A and 4B. Designed to expand and contract equally. Accordingly, by applying mutually opposite voltages to the thin film piezoelectric elements 4A and 4B attached to the upper surfaces of the support portions 1A and 1B of the thin film piezoelectric substrate 1, the thin film piezoelectric actuators 5A and 5B are applied.
Expands and contracts in directions opposite to each other in the longitudinal directions La and Lb, corresponding to the voltages applied to the thin film piezoelectric elements 4A and 4B.

The thin film piezoelectric actuators 5A and 5A are provided on the slider attaching portion 1C and the slider holding plate 2.
When B expands and contracts in opposite directions to each other, the point of contact between the dimple 6H provided on the load beam 6 and the protrusion 2A protruding from the slider holding plate is set as a rotation center.
A small angular displacement in the R direction is given. The minute angular displacement in the R direction given to the slider attaching portion 1C and the slider holding plate 2 imparts a small angular displacement in the R direction to the slider attached to the upper surface of the slider attaching portion 1C. The magnetic head mounted on the slider is displaced along the surface of the magnetic disk in a minute range in the width direction of each track provided concentrically on the magnetic disk, and moves with high precision. Thus, it is possible to perform the on-track operation for following the track of the magnetic head with high accuracy.

A method for manufacturing a conventional thin film piezoelectric actuator will be described with reference to FIGS. The description will be made only for the thin film piezoelectric actuator 5A.

FIGS. 8A to 8G are cross-sectional views showing respective steps of a conventional method of manufacturing a thin film piezoelectric actuator.

First, as shown in FIG. 8A, an electrode for supplying power to the thin film piezoelectric element 4A is formed on a magnesium oxide substrate 11 used as a sputtering base for forming the thin film piezoelectric element 4A. Top electrode 12,
A thin film piezoelectric member 15 is formed by stacking a thin film of lead zirconate titanate (PZT) 13 as a piezoelectric material and a lower electrode 14 as a power supply electrode by sputtering.
Note that the film forming temperature condition of each thin film in this step is 600
° C, the thickness of each thin film is 200 nm for the upper electrode 12,
The PZT thin film 13 is 3 μm, and the lower electrode 14 is 200 nm.

Next, as shown in FIG. 8B, a necessary portion of the thin film piezoelectric material 15 is protected by a photoresist or the like by a photolithography process and a developing process, and thereafter, a chemical etching process of etching an unnecessary portion with a chemical solution. Alternatively, the thin film piezoelectric element 15A formed on the magnesium oxide substrate 11 is formed into a predetermined shape by a reactive ion etching process of etching an unnecessary portion with a reactive gas, and the thin film piezoelectric element 4A is formed.

Next, as shown in FIG. 8C, a photosensitive polyimide 16 is applied to the surfaces of the magnesium oxide substrate 11 and the thin film piezoelectric element 4A, and the photosensitive polyimide is formed into a predetermined shape by a photolithographic process and a developing process. After forming a terminal hole 17 for taking out the lead wire 18, the photosensitive polyimide 16 is thermally cured.

Thereafter, as shown in FIG. 8D, a magnesium oxide substrate 11 and a heat-cured photosensitive polyimide 1
A Ta / Au thin film is formed by sputtering Ta / Au on the surfaces of the lower electrode 6 and the lower electrode 14 exposed from the terminal hole 17 for taking out the lead wire 18.
A lead wire 18 that is electrically connected to the lower electrode 14 is formed from the / Au thin film by a patterning process.

Next, as shown in FIG. 8E, an adhesive 10 is applied to the upper surface of the support plate 1A provided on the thin film piezoelectric substrate 1, and is then supported by the magnesium oxide substrate 11. The thin film piezoelectric element 4A is attached to the upper surface of the support plate 1A with the lower electrode 14 facing downward, and then the adhesive is cured.

Next, as shown in FIG. 8 (f), the thin film piezoelectric substrate 1 to which the thin film piezoelectric element 4A supported by the magnesium oxide substrate 11 is attached is immersed in a phosphoric acid solution at 60 ° C. The magnesium oxide substrate 11 is removed by chemical etching. After that, the thin-film piezoelectric substrate 1 from which the magnesium oxide substrate 11 has been removed is sufficiently washed with warm water, and then sufficiently dried in a vacuum dryer.

Finally, as shown in FIG. 8 (g), the lead wire 18 drawn out of the thin film piezoelectric element 4A is connected to a thin film provided on the base end side of the support 1A of the thin film piezoelectric substrate 1. The top electrode 12 is electrically connected to the piezoelectric element connection terminal 23A and the thin film piezoelectric element connection terminal 23B using the lead 19, respectively. Then, the thin film piezoelectric element 4
A, adhesive 10 and leads 19 are entirely covered with polyimide resin 9. Thereby, the thin film piezoelectric actuator 5A shown in FIG. 7 is obtained.

[0042]

In such a thin film piezoelectric actuator, the thin film piezoelectric elements 4A and 4B
The lead wires 18 need to be formed on the upper surfaces of the support portions 1A and 1B, respectively.
Also, when mounting the thin film piezoelectric elements 4A and 4B and the thin film piezoelectric body connecting terminals provided on the thin film piezoelectric body substrate 1, even when mounting the thin film piezoelectric elements 4A and 4B,
It is necessary to provide a plurality of leads 19. Therefore, there is a problem that the thin film piezoelectric actuator cannot be easily manufactured.

Further, in the manufactured thin film piezoelectric actuator, it is necessary to provide a plurality of leads 19 for applying a voltage to the upper electrode 12 and the lower electrode 14 constituting the thin film piezoelectric elements 4A and 4B. By providing the plurality of leads 19 in this way, a conduction failure may occur in the electrical connection portions, and the reliability of the thin film piezoelectric actuator may be reduced.

An object of the present invention is to solve such a problem. An object of the present invention is to make it possible to easily manufacture a thin film piezoelectric actuator and to apply a voltage to a thin film piezoelectric element without fail. And a method of manufacturing the same.

[0045]

According to a thin film piezoelectric actuator of the present invention, a thin film piezoelectric element is used in a head support mechanism provided with a head for reproducing at least data on a rotationally driven disk on a substrate. A thin film piezoelectric actuator for a disk device for deforming a substrate to displace the head, wherein the thin film piezoelectric element is directly and electrically conductively bonded to a metal plate constituting the substrate, and the thin film piezoelectric element is The surface of the metal plate to be bonded has an uneven shape.

The height difference between the irregularities on the surface of the metal plate is 0.4 μm or more.

According to the method of manufacturing a thin film piezoelectric actuator of the present invention, in a head support mechanism provided with at least a head for reproducing data from a rotationally driven disk on a substrate, the substrate is thinned by a thin film piezoelectric element. A method for manufacturing a thin-film piezoelectric actuator for a disk device for deforming and displacing a head, comprising the steps of: forming a surface of a metal plate constituting a substrate into an uneven shape; and forming a thin film on the uneven surface of the metal plate. Bonding the piezoelectric element directly in an electrically conductive state with an adhesive.

The surface unevenness of the metal plate is provided by a sand blast process.

The surface irregularities of the metal plate are provided by an etching process.

The surface irregularities of the metal plate are provided by a sputtering process.

The surface unevenness of the metal plate is provided by a process of mechanically sliding the wrapping tape.

[0052]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to FIGS.

The present invention is applied to a pair of thin film piezoelectric actuators 5A and 5B in the head support mechanism shown in FIGS. 5 to 8. FIG. 1 shows one thin film piezoelectric actuator 5A of the present invention. FIG.
The other thin film piezoelectric actuator 5B and the thin film piezoelectric actuator 5A have the same configuration.

The thin film piezoelectric actuator 5 shown in FIG.
A is configured together with one supporting portion 1A of the thin-film piezoelectric substrate 1, and the copper plate 8 forming the supporting portion 1A extends to the terminal holding portion 1H and is provided on the terminal holding portion 1H. It is connected to the connection terminal 24B. The copper plate 8 of the other support portion 1B also extends to the terminal holding portion 1H while being insulated from the copper plate 8 of the support portion 1A, and is connected to the external connection terminal 24H provided on the terminal holding portion 1H.

The surface of the copper plate 8 on which the thin film piezoelectric element 4A is mounted is formed in an uneven shape. The height difference of the unevenness is, for example, 0.8 μm or more.

The thin-film piezoelectric element 4 A has an upper electrode 1 on the upper and lower surfaces of a lead zirconate titanate (PZT) thin film 13.
The lower electrode 14 of the thin-film piezoelectric element 4A is directly adhered to the uneven surface of the copper plate 8 in an electrically conductive state by an adhesive.

The upper electrode 12 is connected by leads 19 to thin film piezoelectric element connection terminals 23 A arranged side by side with the copper plate 8. Terminal for connecting thin film piezoelectric element 23A
Extends to the terminal holding portion 1H as described above, and the external connection terminals 24A provided on the terminal holding portion 1H.
It is connected to the. The lead 19 is made of a wire, a silver paste or the like.

The copper plate 8 and the thin-film piezoelectric element 4 A are covered with the polyimide resin 9 together with the leads 19.

FIGS. 2A to 2G are cross-sectional views showing steps of a method of manufacturing a thin film piezoelectric actuator according to the present invention.

First, as shown in FIG. 2A, an electrode for supplying power to the thin film piezoelectric element 4A is formed on a magnesium oxide substrate 11 used as a sputtering base for forming the thin film piezoelectric element 4A. Top electrode 12,
A thin film piezoelectric body 15 is formed by laminating a lead zirconate titanate (PZT) thin film 13 as a piezoelectric material and a lower electrode 14 as a power supply electrode by sputtering. Note that the film forming temperature conditions for each thin film in this step are 6
The temperature of the upper electrode 12 was set to 200 n.
m, PZT thin film 13 is 3 μm, lower electrode 14 is 200 n
m.

Next, as shown in FIG. 2B, a thin film piezoelectric material 15 is formed by a photolithographic process and a developing process.
A thin film piezoelectric body 15 is formed by a chemical etching process of etching unnecessary portions with a chemical solution or a reactive ion etching process of etching unnecessary portions with a reactive gas. To form the thin film piezoelectric element 4A.

On the other hand, a thin film piezoelectric substrate 1 is prepared. FIG. 2C is a cross-sectional view of one supporting portion 1 </ b> A provided on the thin film piezoelectric substrate 1. The support portion 1A has a copper plate 8 as a metal plate extending to the terminal holding portion 1H, and a part of the upper surface of the copper plate 8 is removed by removing a part of the upper surface of the metal plate of the polyimide resin 9. Is processed so that is exposed. The copper plate 8 extending to the terminal holding portion 1H is also provided on the other support portion 1B.
Are provided in an insulated state.

When the support portion 1A of the substrate 1 for thin film piezoelectric material is prepared, as shown in FIG. 2D, the surface exposed from the polyimide resin 9 of the copper plate 8 is provided with an uneven shape by a sandblasting process. . At this time, the height difference of the uneven shape given to the exposed surface of the copper plate 8 is set to about 0.8 μm.

Next, as shown in FIG. 2 (e), an adhesive 10 is applied to the surface of the copper plate 8 provided with the uneven shape, and the thin film piezoelectric element supported by the magnesium oxide substrate 11 is further placed thereon. 4A is attached with the lower electrode 14 facing downward, and then the adhesive is cured. Thereby, the lower surface electrode 14 of the thin film piezoelectric element 4A and the copper plate 8 are directly connected in a conductive state.

Next, as shown in FIG. 2 (f), the thin film piezoelectric substrate 1 to which the thin film piezoelectric element 4A supported by the magnesium oxide substrate 11 is attached is immersed in a phosphoric acid solution at 60 ° C. The magnesium oxide substrate 11 is removed by chemical etching. Thereafter, the thin-film piezoelectric substrate 1 from which the magnesium oxide substrate 11 has been removed is sufficiently washed with warm water and sufficiently dried in a vacuum dryer.

In such a state, the upper electrode 12 of the thin film piezoelectric element 4A and the thin film piezoelectric connecting terminal 23A arranged side by side on the copper plate 8 are electrically connected by the leads 19. Thereafter, as shown in FIG. 2G, the entire thin film piezoelectric element 4A and the leads 19 are covered with the polyimide resin 9. Thus, the thin film piezoelectric actuator 5A shown in FIG. 1 is obtained.

The thin-film piezoelectric actuator 5A manufactured in this manner is applied with a voltage to each terminal provided on the terminal holding portion 1H, and operates according to the same operating principle as the thin-film piezoelectric actuator shown in FIG. Expresses a similar function.

In the present invention, the surface of the copper plate 8 is provided with an uneven shape having a height difference of about 0.8 μm by the sand blast process, whereby the lower surface electrode 14 provided on the thin film piezoelectric element 4A and the copper plate 8 are formed. Are in a conductive state and are firmly connected. If the height difference of the uneven shape provided on the surface of the copper plate 8 is smaller than 0.4 μm, there is a possibility that each lower electrode 14 and the copper plate 8 cannot be electrically connected, and further, each lower electrode 14 and the copper plate 8, the adhesive strength of the thin film piezoelectric element 4A to the surface of the copper plate 8 is also reduced. In order to firmly connect each lower surface electrode 14 of the thin film piezoelectric element 4A to the copper plate 8 in a conductive state, it is more preferable that the height difference is 0.8 μm or more.

Although the sand blast process is used as a means for providing the surface of the copper plate 8 with an uneven shape, the sand blast process may be used even if the unevenness is applied by applying a chemical etching process or sliding a lapping tape or the like. The same effect can be obtained.

Further, in order to control the concavo-convex shape to be applied, a protective resist film having a predetermined pattern is formed in advance on the surface of the copper plate 8 using a photolithographic technique, and thereafter, a chemical etching process, a dry etching process, or a The same effect as in the case of using the sand blast process can be obtained even with the uneven shape obtained by subjecting the surface of the copper plate 8 to unevenness by a sputtering process or the like and removing the resist.

[0071]

According to the thin film piezoelectric actuator of the present invention, a complicated process for forming a lead wire on a thin film piezoelectric element, which has been indispensable until now, is not required, and the thin film piezoelectric actuator can be easily manufactured. It becomes possible to manufacture. In addition, power can be effectively and reliably supplied to the thin-film piezoelectric element, and the electrical reliability of a suspension mounted with the thin-film piezoelectric actuator is improved. Furthermore, by controlling the height difference of the uneven shape on the surface of the metal plate to which the thin film piezoelectric element is bonded, it is also possible to control the adhesive strength of the thin film piezoelectric element to the metal plate surface.

[Brief description of the drawings]

FIG. 1 is a sectional view of one side of a thin film piezoelectric actuator of the present invention.

FIG. 2 is a cross-sectional view illustrating an example of an embodiment of a method for manufacturing a thin-film piezoelectric actuator of the present invention.

FIG. 3 is a perspective view of an example of a suspension on which a conventional thin film piezoelectric actuator is mounted.

FIG. 4 is an exploded perspective view of an example of a suspension equipped with a conventional thin film piezoelectric actuator.

FIG. 5 is a plan view for explaining the operation of the thin film piezoelectric actuator.

FIG. 6 shows a conventional thin film piezoelectric actuator AA ′.
It is a cross section schematic diagram in a line.

FIG. 7 is a sectional view of one side of a conventional thin film piezoelectric actuator.

FIG. 8 is a cross-sectional view showing an example of an embodiment of a method for manufacturing a conventional thin film piezoelectric actuator.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Thin film piezoelectric substrate 1A, 1B Support part 1C Slider attaching part 1D Substrate holding part 1E, 1F Elastic hinge part 1G Wiring part 1H Terminal holding part 2 Slider holding plate 2A Projection part 3 Stainless steel plate 4A, 4B Thin film piezoelectric element 5A, 5B Thin film piezoelectric actuator 6 Load beam 6A Base 6B Circular opening 6C Neck 6D Triangular opening 6E Beam 6F Regulator 6G Mounting 6H Dimple 6I, 6J Plate spring 7 Base plate 8 Copper plate 9 Polyimide resin DESCRIPTION OF SYMBOLS 10 Adhesive 11 Magnesium oxide base material 12 Upper electrode 14 Lower electrode 13 PZT thin film 15 Thin film piezoelectric material 16 Photosensitive polyimide 17 Terminal hole 18 Lead wire 19 Lead 20 First wiring pattern 20A-D Wiring line 21 Second wiring pattern 21A- D Wiring line 22A-D Slider connection terminals 23A to D Thin film piezoelectric element connection terminals 24A to H External connection terminals 25 Suspension

Continued on the front page (72) Inventor Kaoru Matsuoka 1006 Kazuma Kadoma, Kazuma, Osaka Prefecture F-term (reference) in Matsushita Electric Industrial Co., Ltd. 5D042 AA07 GA01 KA03 KA09 5D068 AA01 BB01 CC12 EE15 GG03 5D096 AA02 NN03

Claims (7)

[Claims] 1. A disk drive in which a thin film piezoelectric element deforms a substrate and displaces the head in a head support mechanism provided with a head for reproducing at least data on a rotationally driven disk. A thin film piezoelectric actuator for use in which a thin film piezoelectric element is directly bonded in a conductive state to a metal plate constituting a substrate, and the surface of the metal plate to which the thin film piezoelectric element is bonded has an uneven shape. A thin film piezoelectric actuator. 2. The thin-film piezoelectric actuator according to claim 1, wherein the height difference of the uneven shape on the surface of the metal plate is 0.4 μm or more. 3. A disk drive in which a thin film piezoelectric element deforms a substrate and displaces the head in a head support mechanism provided with a head for reproducing at least data on a rotationally driven disk. A method of manufacturing a thin-film piezoelectric actuator for use, comprising the steps of: forming a surface of a metal plate constituting a substrate into an uneven shape; and directly bonding the thin-film piezoelectric element to the uneven surface of the metal plate by an adhesive. And a step of bonding in a conductive state. 4. The method for manufacturing a thin film piezoelectric actuator according to claim 3, wherein the surface irregularities of the metal plate are provided by a sandblasting process. 5. The method for manufacturing a thin film piezoelectric actuator according to claim 3, wherein the surface irregularities of the metal plate are provided by an etching process. 6. The method for manufacturing a thin-film piezoelectric actuator according to claim 3, wherein the surface irregularities of the metal plate are provided by a sputtering process. 7. The method for manufacturing a thin film piezoelectric actuator according to claim 3, wherein the surface unevenness of the metal plate is provided by a process of mechanically sliding a wrapping tape.