Thin-film piezoelectric material element, head gimbal assembly and hard disk drive

The present invention relates to a thin-film piezoelectric material element which has a piezoelectric material and electrodes having thin-film like shape, head gimbal assembly and hard disk drive having the thin-film piezoelectric material element.

Related Background Art

A hard disk drive has a large recording capacity and is used as the heart of a storage device. The hard disk drive records and reproduces data to/from a hard disk (recording medium) by a thin-film magnetic head. A part, which the thin-film magnetic head is formed, is called as a head slider, and a part, which the head slider is mounted on the edge part, is a head gimbal assembly (will also be referred to as HGA).

Further, recording and reproducing of data to/from the recording medium is performed by flying the head slider from a surface of the recording medium while rotating the recording medium, in the hard disk drive.

On the other hand, it has become difficult to control a position of the thin-film magnetic head accurately by control with only a voice coil motor (VCM), because heightening a recording density of the recording medium has developed in company with increase of a capacity of the hard disk drive. Therefore formerly, a technology, which an actuator having supplementary function (a supplementary actuator) is mounted on the HGA in addition to a main actuator with the VCM, and the supplementary actuator controls a minute position that is not able to be controlled by the VCM, is known.

A technology, which the main actuator and the supplementary actuator control the position of the thin-film magnetic head, is also called two stage actuator system (dual-stage system).

In the two stage actuator system, the main actuator makes drive arms rotate to decide a position of the head slider on a specific track of the recording medium. Further, the supplementary actuator adjusts the position of the head slider minutely so that the position of the thin-film magnetic head may become an optimum position.

A micro actuator using a thin-film piezoelectric material element is known formerly as the supplementary actuator. The thin-film piezoelectric material element has a piezoelectric material and a pair of electrodes formed to sandwich the piezoelectric material, and each of them is formed to be a thin-film shape.

Further, a technology, which displacement stroke of the element is increased to increase the displacement control amount of the magnetic head, is conventionally known (for example, see U.S. Pat. No. 8,885,294 (referred also to as Patent Document 1)). The HGA having a following structure is disclosed in the patent document 1. The HGA has the structure which the piezoelectric material element is fixed to the bottom of concave part formed on a gimbal part. It is possible to prevent the stroke of expansion or shrinking of the thin-film piezoelectric material element from escaping in a curved direction, thereby the displacement stroke of thin-film piezoelectric material element increase.

On the other hand, to avoid electrical shorting between the upper electrode film and the lower electrode film, the piezoelectric material element, which the insulating layer made of oxide or poly-imide are formed to wrap on the top surface and side surfaces of four direction of piezoelectric material, is known (for example, see U.S. Pat. No. 6,931,700 (referred to also as Patent Document 2), U.S. Pat. No. 7,006,334 (referred to also as Patent Document 3)). An opening of the insulating layer is formed on the top surface of the piezoelectric material so that the top surface of the piezoelectric material is exposed, in these thin-film piezoelectric material elements. Further, the HGA, having a flexure including a structure with the piezoelectric element, is disclosed in JP 2014-106985 (referred to also as Patent Document 4). The thin-film piezoelectric material element is fixed to the flexure, in the HGA.

As mentioned in the above-described Patent Documents 2-3, thin-film piezoelectric material elements having a structure, which the opening (or via hole) is formed in the insulating layer for securing electrical conduction with piezoelectric material, and an electrode layer is formed on the opening (referred to also as “opening and electrode structure”), is known. The electrode layer is extended from the opening to the outside of the thin-film piezoelectric material element along with the surface of the insulating layer, for securing electrical connection with the outside and electrical supply from the outside, in thin-film piezoelectric material elements disclosed in these documents.

By the way, if an area for mounting the thin-film piezoelectric material element is secured widely in the HGA, an area for mounting the opening and electrode (referred to also as “opening and electrode area”) is able to be secured even which side of an area along with the width direction of piezoelectric material (referred to also as “width direction area”) and an area along with the length direction of piezoelectric material (referred to also as “length direction area”).

In this case, because the piezoelectric material expands and shrinks along with the length direction, if the opening and electrode area is secured in the width direction area, it does not affect length of the piezoelectric material, and it does not affect expanding and shrinking motion of the piezoelectric material. Therefore, it is preferable that the opening and electrode area is secured in the width direction area.

However, a space for accommodating the opening and electrode layer is not able to be secured in the width direction area of the HGA. Therefore, the opening and electrode area needs to be secured in the length direction area.

If the electrode layer is extended along with length direction of the piezoelectric material, it needs shortening of length of the piezoelectric material. In this case, extension of the electrode layer affects expanding and shrinking motion of the piezoelectric material.

On the other hand, concerning a pair of the thin-film piezoelectric material elements, from reliability point of view, it is necessary to keep opening and electrode layer not moving while the other thin-film piezoelectric material element expands and shrinks under the driving voltages. This can be done by make the piezoelectric material elements inactive by overlapping with parts having strong mechanical strength such as stainless substrate.

Further, in case of the thin-film piezoelectric material element overlapped on the stainless substrate, a stroke for expanding and shrinking motion of the thin-film piezoelectric material element is proportional to the length of thin-film piezoelectric material element without overlapping with the stainless substrate, defined as “active length”. Extension of the active length causes increase of the stroke. Accordingly, it is always the goal to design active thin-film piezoelectric material element with active length as longer as possible.

However, the opening and electrode area is secured in the length direction area, in case of the conventional thin-film piezoelectric material element having the opening and electrode structure. Therefore, the active length is limited by the length of total thin-film piezoelectric material element minus length of the opening and electrode area. Further, in accordance with increasing size of the opening and needed electrode layer length, it brings more difficulty about extending of the active length of the thin-film piezoelectric material element.

The present invention is made to solve the above problem, and it is an object to extend the active length, and increase the stroke while having the opening and electrode structure positioned in a long-side direction, in the thin-film piezoelectric material element, head gimbal assembly and hard disk drive.

To solve the above problem, the present invention is a thin-film piezoelectric material element including: a laminated structure part including a lower electrode film, a piezoelectric material film laminated on the lower electrode film and an upper electrode film laminated on the piezoelectric material film; a surface layer insulating film disposed on side surfaces of the laminated structure part and a top surface of the upper electrode film, and has a through hole formed on a top disposed part disposed on the top surface; and an upper electrode pad being in directly contact with an inside exposed surface, exposed inside the through hole, of the upper electrode film; the upper electrode pad arranged entirely inside an outer edge part of the top disposed part, and formed without contact with a side disposed part, formed along with side surfaces of the laminated structure part, of the surface layer insulating film.

In case of the above-described thin-film piezoelectric material element, because the upper electrode pad is arranged entirely inside the outer edge part of the top disposed part, and formed without contact with the side disposed part, larger space than the conventional one is secured in the long-side direction of the thin-film piezoelectric material element.

Further, in case of the above-described thin-film piezoelectric material element, it is preferable that the upper electrode pad has a long pad-length along with a long-side direction of the thin-film piezoelectric material element and a short pad-length along with a short-side direction of the thin-film piezoelectric material element, the long pad-length is shorter than the short pad-length.

Further, the upper electrode pad has an outer end surface formed outside than the top disposed part, the outer end surface is formed entirely flat, and disposed inside than the outer edge part of the top disposed part.

It is preferable that the surface layer insulating film has a long-side disposed part disposed outside than the top disposed part along with a long-side direction of the thin-film piezoelectric material element, the long-side disposed part has a long-side width, along with the long-side direction, formed shorter than the through hole.

Furthermore, the inside exposed surface has a non pad-contact surface, formed partially, being out of contact with the upper electrode pad.

It is possible that the upper electrode pad is formed smaller than the inside exposed surface, the non pad-contact surface is formed so as to surround the upper electrode pad.

Further, it is possible that the outer end surface is disposed entirely inside the through hole.

It is preferable that the outer end surface has an extended part disposed outside than the through hole, the extended part is disposed inside than the outer edge part of the top disposed part.

Further, the present invention provides a thin-film piezoelectric material element including: a laminated structure part including a lower electrode film, a piezoelectric material film laminated on the lower electrode film and an upper electrode film laminated on the piezoelectric material film; and a surface layer insulating film disposed on side surfaces of the laminated structure part and a top surface of the upper electrode film, and has a through hole formed on a top disposed part disposed on the top surface; the surface layer insulating film has a long-side disposed part disposed outside than the top disposed part along with a long-side direction of the thin-film piezoelectric material element, the long-side disposed part has a long-side width, along with the long-side direction, formed shorter than the through hole.

Further, the present invention provides a head gimbal assembly including a head slider having a thin-film magnetic head; a suspension for supporting the head slider; and a thin-film piezoelectric material element for displacing the head slider relatively to the suspension; the thin-film piezoelectric material element including: a laminated structure part including a lower electrode film, a piezoelectric material film laminated on the lower electrode film and an upper electrode film laminated on the piezoelectric material film; a surface layer insulating film disposed on side surfaces of the laminated structure part and a top surface of the upper electrode film, and has a through hole formed on a top disposed part disposed on the top surface; and an upper electrode pad being in directly contact with an inside exposed surface, exposed inside the through hole, of the upper electrode film; the upper electrode pad arranged entirely inside an outer edge part of the top disposed part, and formed without contact with a side disposed part, formed along with side surfaces of the laminated structure part, of the surface layer insulating film.

In case of the above-described head gimbal assembly, it is preferable that the upper electrode pad has an outer end surface formed outside than the upper disposed part, the outer end surface is formed entirely flat, and disposed inside than the outer edge part of the top disposed part, the head gimbal assembly further including: a suspension pad formed on the suspension; and a connecting electrode which connects the outer end surface with the suspension pad.

Further, the present invention provides a head gimbal assembly including a head slider having a thin-film magnetic head; a suspension for supporting the head slider; and a thin-film piezoelectric material element for displacing the head slider relatively to the suspension; the thin-film piezoelectric material element including: a laminated structure part including a lower electrode film, a piezoelectric material film laminated on the lower electrode film and an upper electrode film laminated on the piezoelectric material film; and a surface layer insulating film disposed on side surfaces of the laminated structure part and a top surface of the upper electrode film, and has a through hole formed on a top disposed part disposed on the top surface; the surface layer insulating film has, a long-side disposed part disposed outside than the top disposed part along with a long-side direction of the thin-film piezoelectric material element, the long-side disposed part has a long-side width, along with the long-side direction, formed shorter than the through hole.

In the above-described head gimbal assembly, it is preferable that the head gimbal assembly, further including: a suspension pad formed on the suspension; and a connecting electrode which connects an inside exposed surface, exposed inside the through hole of the upper electrode film, with the suspension pad.

Further, the present invention provides a hard disk drive including a head gimbal assembly including a head slider having a thin-film magnetic head, a suspension for supporting the head slider, a thin-film piezoelectric material element for displacing the head slider relatively to the suspension; and a recording medium; the thin-film piezoelectric material element including: a laminated structure part including a lower electrode film, a piezoelectric material film laminated on the lower electrode film and an upper electrode film laminated on the piezoelectric material film; surface layer insulating film disposed on side surfaces of the laminated structure part and a top surface of the upper electrode film, and has a through hole formed on a top disposed part disposed on the top surface; and an upper electrode pad being in directly contact with an inside exposed surface, exposed inside the through hole, of the upper electrode film; the upper electrode pad arranged entirely inside an outer edge part of the top disposed part, and formed without contact with a side disposed part, formed along with side surfaces of the laminated structure part, of the surface layer insulating film.

Further, the present invention provides a hard disk drive including a head gimbal assembly including a head slider having a thin-film magnetic head, a suspension for supporting the head slider, a thin-film piezoelectric material element for displacing the head slider relatively to the suspension; and a recording medium; the thin-film piezoelectric material element including: a laminated structure part including a lower electrode film, a piezoelectric material film laminated on the lower electrode film and an upper electrode film laminated on the piezoelectric material film; and a surface layer insulating film disposed on side surfaces of the laminated structure part and a top surface of the upper electrode film, and has a through hole formed on a top disposed part disposed on the top surface; the surface layer insulating film has a long-side disposed part disposed outside than the top disposed part along with a long-side direction of the thin-film piezoelectric material element, the long-side disposed part has a long-side width, along with the long-side direction, formed shorter than the through hole.

In case of the above-described hard disk drive, it is preferable that the hard disk drive further including: a suspension pad formed on the suspension; and a connecting electrode which connects an inside exposed surface, exposed inside the through hole of the upper electrode film, with the suspension pad.

The present invention will be more fully understood from the detailed description given hereinbelow and the accompanying drawings which are given by way of illustration only, and thus are not to be considered as limiting the present invention.

FIG. 1 is a perspective view showing a whole of the HGA, from front side, according to an embodiment of the present invention;

FIG. 2 is a perspective view showing, from front side, a principal part of the HGA in FIG. 1 ;

FIG. 3 is a perspective view showing a principal part of a suspension constituting the HGA in FIG. 1 from front side;

FIG. 4 is a perspective view showing a part, which a thin-film piezoelectric material element is fixed, of flexure with enlargement;

FIG. 5 is a plan view showing the thin-film piezoelectric material element and the peripheral part of the HGA in FIG. 1 ;

FIG. 6 is a sectional view taken along the line 6 - 6 in FIG. 5 ;

FIG. 7 is a sectional view taken along the line 7 - 7 in FIG. 5 ;

FIG. 8 is a sectional view, similar with FIG. 6 , showing the thin-film piezoelectric material element connected to a suspension pad by a connecting electrode;

FIG. 9 is a plan view, similar with FIG. 5 , showing the thin-film piezoelectric material element and the peripheral part according to modified example;

FIG. 10 is a sectional view taken along the line 10 - 10 in FIG. 9 ;

FIG. 11 is a sectional view taken along the line 11 - 11 in FIG. 9 ;

FIG. 12 is a sectional view, similar with FIG. 6 , showing the thin-film piezoelectric material element, according to the modified example, connected to the suspension pad by the connecting electrode;

FIG. 13 is a plan view, similar with FIG. 5 , showing the thin-film piezoelectric material element and the peripheral part according to another modified example;

FIG. 14 is a sectional view taken along the line 14 - 14 in FIG. 13 ;

FIG. 15 is a sectional view taken along the line 15 - 15 in FIG. 13 ;

FIG. 16 is a sectional view, similar with FIG. 14 , showing the thin-film piezoelectric material element, according to another modified example, connected to the suspension pad by the connecting electrode;

FIG. 17 is a plan view, similar with FIG. 5 , showing the thin-film piezoelectric material element and the peripheral part according to still another modified example;

FIG. 18 is a sectional view taken along the line 18 - 18 in FIG. 17 ;

FIG. 19 is a sectional view taken along the line 19 - 19 in FIG. 17 ;

FIG. 20 is a sectional view, similar with FIG. 19 , showing the thin-film piezoelectric material element, according to still another modified example, connected to the suspension pad by the connecting electrode;

FIG. 21 ( a ) is a sectional view showing a principal part of the conventional thin-film piezoelectric material element, FIG. 21 ( b ) is a sectional view showing a principal part of another conventional thin-film piezoelectric material element;

FIG. 22 ( a ) is a view schematically showing stroke of the thin-film piezoelectric material element in FIG. 21 ( a ) , FIG. 22 ( b ) is a view schematically showing stroke of the thin-film piezoelectric material element in FIG. 21 ( b ) ;

FIG. 23 ( a ) is a plan view showing the thin-film piezoelectric material elements according to the embodiment of the present embodiment, FIG. 23 ( b ) is a plan view showing the conventional thin-film piezoelectric material element;

FIG. 24 is a plan view showing the thin-film piezoelectric material element and the peripheral part in the conventional HGA;

FIG. 25 is a sectional view taken along the line 25 - 25 in FIG. 24 ;

FIG. 26 is a sectional view, similar with FIG. 25 , showing the thin-film piezoelectric material element in FIG. 24 connected to the suspension pad by the connecting electrode; and

FIG. 27 is a perspective view showing a hard disk drive equipped with the HGA according to the embodiment of the present invention.

In the following, embodiments of the present invention will be described with reference to the drawings. Note that the same components will be referred to with the same numerals or letters, while omitting their overlapping descriptions.

(Structure of HGA)

To begin with, a structure of the HGA according to the embodiment of the present invention will be explained with reference to FIG. 1 to FIG. 4 . Here, FIG. 1 is a perspective view showing a whole of the HGA 1 , from front side, according to an embodiment of the present invention. FIG. 2 is a perspective view showing a principal part of the HGA 1 from front side. FIG. 3 is a perspective view showing a principal part of the suspension 50 constituting the HGA 1 from front side. Further, FIG. 4 is a perspective view showing a part, which a thin-film piezoelectric material element 12 b is fixed, of a flexure 6 with enlargement.

As illustrated in FIG. 1 , the HGA 1 has the suspension 50 and a head slider 60 . The suspension 50 has a base plate 2 , a load beam 3 , the flexure 6 and a dumper not illustrated, and it has a structure which these parts are joined to be united one body by a weld and so on.

The base plate 2 is a part which is used to fix the suspension 50 to a drive arms 209 of a later-described hard disk drive 201 , and it is formed with a metal such as stainless steel or the like.

The load beam 3 is fixed on the base plate 2 . The load beam 3 has a shape in which the width gradually decreases as it is distanced more from the base plate 2 . The load beam 3 has a load bending part which generates a power for pressing the head slider 60 against the later-described hard disk 202 of the hard disk drive 201 .

Further, as illustrated in FIG. 1 to FIG. 4 , the flexure 6 has a flexure substrate 4 , a base insulating layer 5 , a connecting wiring 11 and thin-film piezoelectric material elements 12 a , 12 b . The flexure 6 has a structure which the base insulating layer 5 is formed on the flexure substrate 4 , the connecting wiring 11 and thin-film piezoelectric material elements 12 a , 12 b are adhered on the base insulating layer 5 . Further, the not illustrated protective insulating layer is formed so as to cover the connecting wiring 11 and thin-film piezoelectric material elements 12 a , 12 b.

The flexure 6 has a piezoelectric elements attached structure which thin-film piezoelectric material elements 12 a , 12 b are fixed on the surface of the base insulating layer 5 in addition to the connecting wiring 11 to become a structure with piezoelectric element.

Further, the flexure 6 has a gimbal part 10 on the tip side (load beam 3 side). A tongue part 19 , which the head slider 60 is mounted, is secured on the gimbal part 10 , and a plurality of connecting pads 20 are formed near an edge side than the tongue part 19 . Connecting pads 20 are electrically connected to not-illustrated electrode pads of the head slider 60 .

This flexure 6 expands or shrinks thin-film piezoelectric material elements 12 a , 12 b and expands or shrinks stainless part (referred to out trigger part) jut out outside of the tongue part 19 . That makes a position of the head slider 60 move very slightly around not-illustrated dimple, and a position of the head slider 60 is controlled minutely.

The flexure substrate 4 is a substrate for supporting a whole of the flexure 6 , and it is formed with stainless. Rear side of the flexure substrate 4 is fixed to the base plate 2 and the load beam 3 by weld. As illustrated in FIG. 1 , the flexure substrate 4 has a center part 4 a fixed to surfaces of the load beam 3 and the base plate 2 , and a wiring part 4 b extending to outside from the base plate 2 .

The base insulating layer 5 covers s surface of the flexure substrate 4 . The base insulating layer 5 is formed with for example polyimide, and it has a thickness of about 5 μm to 10 μm. Further, as illustrated in detail in FIG. 3 , a part of the base insulating layer 5 , disposed on the load beam 3 , is divided two parts. One part of them is a first wiring part 5 a , the other part of them is second wiring part 5 b . The thin-film piezoelectric material element 12 a and thin-film piezoelectric material element 12 b are adhered on surfaces of each wiring part.

A plurality of connecting wirings 11 are formed on surfaces of each of the first wiring part 5 a and the second wiring part 5 b . Each connecting wiring 11 is formed with conductor such as copper or the like. One end parts of each connecting wiring 11 are connected to the thin-film piezoelectric material elements 12 a , 12 b or each connecting pad 20 .

The not-illustrated protective insulating layer is formed with for example polyimide. The protective insulating layer has a thickness of about 1 μm to 2 μm, for example.

Further, a not illustrated thin-film magnetic head, which re records and reproduces data, is formed on the head slider 60 . Furthermore, a plurality of not illustrated electrode pads are formed on the head slider 60 , and each electrode pad is connected to the connecting pad 20 .

(Structure of Thin-Film Piezoelectric Material Element)

Subsequently, the structure of thin-film piezoelectric material element 12 b will be explained with reference to FIG. 5 to FIG. 8 . Here, FIG. 5 is a plan view showing the thin-film piezoelectric material element 12 b and the peripheral part of the HGA 1 . FIG. 6 is a sectional view taken along the line 6 - 6 in FIG. 5 , FIG. 7 is a sectional view taken along the line 7 - 7 in FIG. 5 . FIG. 8 is a sectional view, similar with FIG. 6 , showing the thin-film piezoelectric material element 12 b connected to a suspension pad 26 by a connecting electrode 18 b . Note that the connecting electrode 18 b is omitted in FIGS. 5-7 for convenience of illustration.

The thin-film piezoelectric material element 12 b (similar to thin-film piezoelectric material element 12 a ), as illustrated in FIG. 5 - FIG. 8 , has a laminated structure part 21 , a surface layer insulating film 22 , an upper electrode pad 24 A and a lower electrode pad 24 B.

The thin-film piezoelectric material elements 12 b , 12 a are adhered to the surface of the base insulating layer 5 with epoxy resin. A resin layer 28 made of the epoxy resin is formed between the laminated structure part 21 and the base insulating layer 5 .

The thin-film piezoelectric material elements 12 b is formed with a rectangular shape in a plan view, as illustrated in detail in FIG. 5 . A pad region 25 is secured at one side along with a long-side direction of the thin-film piezoelectric material elements 12 b . The pad region 25 is a region from a boundary line 22 e of a later-described top disposed part 22 a and a side disposed part 22 b to an upper electrode pad 24 A and a lower electrode pad 24 B. The upper through hole 23 A, lower through hole 23 B, the upper electrode pad 24 A and lower electrode pad 24 B are formed in the pad region 25 .

Note that “upper” and “lower” in the present invention do not show necessarily upper side, lower side in a condition which the thin-film piezoelectric material element is adhered on the base insulating layer 5 . These words are terms for reasons of convenience so as to distinguish two upper, lower electrode films 21 b , 21 c and so on opposing each other sandwiching the piezoelectric material film 21 a their between. In the actual products, the upper electrode film 21 b is sometimes disposed lower side, and the lower electrode film 21 c is sometimes disposed upper side.

The laminated structure part 21 has the piezoelectric material film 21 a , the lower electrode film 21 c and the upper electrode film 21 b . The piezoelectric material film 21 a is laminated on the lower electrode film 21 c , the upper electrode film 21 b is laminated on the piezoelectric material film 21 a . The laminated structure part 21 has laminated structure formed of the piezoelectric material film 21 a , the lower electrode film 21 c and the upper electrode film 21 b.

The piezoelectric material film 21 a is formed to be a thin-film shape using a piezoelectric material such as lead zirconate titanate ((Pb (Zr,Ti) O 3 ) which will also be referred to as “PZT” in the following) or the like. The piezoelectric material film 21 a is formed by epitaxial growth and it has a thickness of about 2 μm to 5 μm. A piezoelectric ceramics (much of them are ferroelectric substance) such as barium titanate, lead titanate or the like, non-lead system piezoelectric ceramics not including titanium or lead are able to be used for the piezoelectric material film 21 a instead of using PZT.

The lower electrode film 21 c is a thin-film (thickness about 100 nm) made of metal element which has Pt (it may include Au, Ag, Pd, Ir, Ru, Cu, in addition to Pt) as main ingredient, it is formed on the base insulating layer 5 . A crystal structure of the lower electrode film 21 is a face-centered cubic structure.

Note that a lower adhesive film is preferably formed between the lower electrode film 21 c and the piezoelectric material film 21 a , not illustrated though. The lower adhesive film is a thin-film (thickness about 20 nm) made of conductive material formed by epitaxial growth such as SrRuO 3 (referred to also as SRO) or the like, it is able to be formed on top surface, of the lower electrode film 21 c , of the piezoelectric material film 21 a side. The piezoelectric material film 21 a is able to be formed on the lower adhesive film.

The upper electrode film 21 b is a polycrystal thin-film (thickness about 50 nm) with metal element which has Pt (it may include Au, Ag, Pd, Ir, Rh, Ni, Pb, Ru, Cu, in addition to Pt) as main ingredient, it is formed on the piezoelectric material film 21 a . The upper electrode film 21 b has a figure which the part under the lower through hole 23 B and the peripheral part are lacked (hereinafter, referred also to as “partial lacked figure), so as not to be in touch with later-described lower electrode pad 24 B.

Further, not illustrated though, an upper adhesive film is preferably formed between the piezoelectric material film 21 a and the upper electrode film 21 b . The upper adhesive film is a thin-film (thickness about 35 nm) made of amorphous conductive material such as SrRuO 3 or the like, and it is formed on the piezoelectric material film 21 a.

The surface layer insulating film 22 is disposed on the top surface and side surfaces of four direction of the laminated structure part 21 , and it is formed so as to cover the top surface and side surfaces of four direction of the laminated structure part 21 . The surface layer insulating film 22 is formed with insulating material such as polyimide or the like. The surface layer insulating film 22 has a top disposed part 22 a , a side disposed part 22 b , and a long-side disposed part 22 c.

The top disposed part 22 a is a part disposed on the top surface of laminated structure part 21 . The top disposed part 22 a is formed directly on the top surface 21 ba of the upper electrode film 21 b . One end side of the long-side direction of the top disposed part 22 a is assigned to the pad region 25 .

The side disposed part 22 b is a part disposed on a long-side side surfaces of the laminated structure part 21 . The long-side side surfaces are a pair of side surfaces along the long-side direction of the thin-film piezoelectric material element 12 b among four side surfaces. The side disposed parts 22 b are formed directly on the long-side side surfaces of the laminated structure part 21 . The long-side disposed parts 22 c are connected to the lower end part of the side disposed parts 22 b.

The long-side disposed parts 22 c is a part projected outside from the side disposed parts 22 b along the long-side direction. The long-side disposed parts 22 c is formed directly on the base insulating layer 5 . A length of the long-side disposed parts 22 c along the long-side direction (hereinafter, referred also to as “long-side length”) L 22 c is shorter than later-described long-side length L 23 (L 22 c <L 23 ). Therefore, in the thin-film piezoelectric material element 12 b , the side disposed parts 22 b are brought near to later-described suspension pad 26 though, even so the long-side disposed parts 22 c is not in contact with the suspension pad 26 .

The upper through hole 23 A is formed in the pad region 25 of the top disposed part 22 a . The upper through hole 23 A penetrates the top disposed part 22 a , as illustrated in FIG. 6 . The top surface of the upper electrode film 21 b is exposed, inside the upper through hole 23 A, as an inside exposed surface 21 bb having rectangular shape in a plan view.

The lower through hole 23 B is also formed in the pad region 25 of the top disposed part 22 a . The lower through hole 23 B penetrates the top disposed part 22 a similar with the upper through hole 23 A, as illustrated in FIG. 7 . Because the upper electrode film 21 b is formed with above-described partial lacked figure, surface of the piezoelectric material film 21 a is exposed, inside the lower through hole 23 B, as an inside exposed surface 21 aa having rectangular shape in a plan view.

The upper electrode pad 24 A is formed inside the upper through hole 23 A. The upper electrode pad 24 A is formed in a rectangular parallelepiped shape. The upper electrode pad 24 A is in directly contact with the inside exposed surface 21 bb which is a surface of the upper electrode film 21 b . The upper electrode pad 24 A is entirely disposed inside an outer edge part 22 d (outermost peripheral part of the top disposed part 22 a ). Further, the upper electrode pad 24 A is formed without contact with the side disposed parts 22 b.

Then, the upper electrode pad 24 A has a long-pad length L 24 and a short-pad length W 24 . The long-pad length L 24 is a length of the upper electrode pad 24 A along with long-side direction of the thin-film piezoelectric material element 12 b . The short-pad length W 24 is a length of the upper electrode pad 24 A along with short-side direction of the thin-film piezoelectric material element 12 b . Further, the long-pad length L 24 is shorter than the short-pad length W 24 (L 24 <W 24 ).

Further, the upper electrode pad 24 A has an outer end surface 24 AS having rectangular shape in a plan view. A fine mesh pattern is drawn in the outer end surface 24 AS, as illustrated in FIG. 5 . The outer end surface 24 AS is formed outside the top disposed part 22 a , as illustrated in FIG. 6 . The outer end surface 24 AS is entirely flat. The outer end surface 24 AS is disposed inside the outer edge part 22 d , and disposed inside the upper through hole 23 A. Note that rough mesh pattern is drawn in the suspension pad 26 , in FIG. 5 .

Furthermore, the upper electrode pad 24 A is formed in a size smaller than the inside exposed surface 21 bb . A gap is secured between the upper electrode pad 24 A and inside side surface of the upper through hole 23 A. And, a part of the inside exposed surface 21 bb is a non pad-contact surface being out of contact with the upper electrode pad 24 A. The non pad-contact surface is formed in a circular shape which surrounds periphery of the upper electrode pad 24 A.

The lower electrode pad 24 B has an upper pad part 24 Ba and a lower pad part 24 Bb, as illustrated in FIG. 7 . The upper pad part 24 Ba is connected with the top surface of the lower pad part 24 Bb. The upper pad part 24 Ba and the lower pad part 24 Bb are formed in the rectangular parallelepiped shape respectively.

The upper pad part 24 Ba is formed inside the lower through hole 23 B. The upper pad part 24 Ba is entirely disposed inside the outer edge part 22 d similar with the upper electrode pad 24 A. Further, the upper pad part 24 Ba is formed without contact with the side disposed parts 22 b.

The upper pad part 24 Ba has the same long-pad length L 24 and short-pad length W 24 as the upper electrode pad 24 A. Further, the upper pad part 24 Ba has the same outer end surface 24 BS having rectangular shape in a plan view as the upper electrode pad 24 A. As illustrated in FIG. 5 , the same fine mesh pattern is also drawn in the outer end surface 24 BS as the outer end surface 24 AS. The outer end surface 24 BS is entirely flat. The outer end surface 24 BS is disposed entirely inside the outer edge part 22 d , and disposed inside the upper through hole 23 A.

Furthermore, the upper pad part 24 Ba is formed in a size smaller than the inside exposed surface 21 aa similar with the upper electrode pad 24 A, and the gap is also secured between the upper pad part 24 Ba and inside side surface of the lower through hole 23 B. And, a part of the inside exposed surface 21 aa is formed the non pad-contact surface being out of contact with the upper pad part 24 Ba. The non pad-contact surface is formed in a circular shape which surrounds periphery of the upper pad part 24 Ba.

The lower pad part 24 Bb penetrates the piezoelectric material film 21 a . The lower pad part 24 Bb is embedded in a hole part of the piezoelectric material film 21 a . The top surface of the lower pad part 24 Bb is exposed in the top surface of the piezoelectric material film 21 a , the upper pad part 24 Ba is connected to the top surface of the lower pad part 24 Bb. The lower pad part 24 Bb is directly contact with the top surface of the lower electrode film 21 c.

The thin-film piezoelectric material elements 12 b , having the above-described structure, is connected to suspension pads 26 , 26 with connecting electrode 18 b (referred to also connecting pad, can be formed with solder, for example). In this case, connecting electrodes 18 b , 18 b connect outer end surfaces 24 AS, 24 BS of the upper, lower electrode pad 24 A, 24 B to suspension pads 26 , 26 , respectively.

Note that connecting wiring 11 and thin-film piezoelectric material elements 12 b , 12 a are shown in FIG. 2 to FIG. 4 , for illustration of convenience, they are not exposed in the surface of the flexure 6 , because they are cover with not-illustrated protective insulating layer.

(Operation and Effect of Thin-Film Piezoelectric Material Element)

Subsequently, operation and effect of the thin-film piezoelectric material element 12 b having the above-described structure will be explained with comparing the thin-film piezoelectric material element 12 b according to the embodiment of the present invention with a conventional thin-film piezoelectric material element 112 b.

First of all, the conventional thin-film piezoelectric material element 112 b will be explained as follows. The conventional thin-film piezoelectric material element 112 b is shown in FIG. 24 , FIG. 25 , FIG. 26 . Here, FIG. 24 is a plan view showing the thin-film piezoelectric material element 112 b and the peripheral part in the conventional HGA. FIG. 25 is a sectional view taken along the line 25 - 25 in FIG. 24 . FIG. 26 is a sectional view, similar with FIG. 25 , showing the thin-film piezoelectric material element 112 b connected to the suspension pad 26 by the connecting electrode 118 b.

The conventional thin-film piezoelectric material element 112 b has a laminated structure part 121 , a surface layer insulating film 122 , an upper electrode pad 124 A and a lower electrode pad 124 B. The thin-film piezoelectric material elements 112 b is adhered to the surface of the base insulating layer 5 with epoxy resin similar with the thin-film piezoelectric material element 12 b . Therefore, a resin layer 28 made of the epoxy resin is formed between the laminated structure part 121 and the base insulating layer 5 .

The thin-film piezoelectric material elements 112 b is formed with the same rectangular shape with the thin-film piezoelectric material elements 12 b , a pad region 125 is secured in one side along with a long-side direction of the thin-film piezoelectric material elements 112 b . The pad region 125 is a region from a boundary line 122 e of a later-described top disposed part 122 a and a side disposed part 122 b of the surface layer insulating film 122 to upper, lower electrode pads 124 A, 124 B.

The laminated structure part 121 has the upper electrode film 121 b , the piezoelectric material film 121 a and the lower electrode film 121 c . The laminated structure part 121 has the same three-layers structure with the laminated structure part 21 . However, the active length ALX is shorter than the active length AL of the thin-film piezoelectric material elements 12 b.

The surface layer insulating film 122 is different in that it has a top disposed part 122 a , a side disposed part 122 b , and a long-side disposed part 122 c as compared with the surface layer insulating film 22 . The top disposed part 122 a is a part disposed on the top surface of laminated structure part 121 , the side disposed part 122 b is a part disposed on long-side side surfaces of the laminated structure part 121 , and the long-side disposed parts 122 c is a part projected outside from the side disposed parts 122 b along the long-side direction. The long-side length L 122 c is longer than later-described long-side length L 123 (L 122 c >L 123 ). The surface layer insulating film 122 differs from the surface layer insulating film 22 in this point greatly.

The upper, lower through holes 123 A, 123 B are different in that parts of upper, lower electrode pads 124 A, 124 B are formed inside them respectively without gap, as compared with the upper, lower through holes 23 A, 23 B. Further, the upper, lower through holes 123 A, 123 B are different in that the upper, lower through holes 123 A, 123 B are smaller than later-described outer end surfaces 124 AS, 124 BS of the upper, lower electrode pad 124 A, 124 B, as compared with the upper, lower through holes 23 A, 23 B.

The upper, lower electrode pads 124 A, 124 B are directly in contact with surfaces of the upper, lower electrode films 121 b , 121 c respectively as the upper, lower electrode pads 24 A, 24 B are directly in contact with surfaces of the upper, lower electrode films 21 b , 21 c respectively. However, the upper, lower electrode pads 124 A, 124 B and the upper, lower electrode pads 24 A, 24 B are different in the following A) to F).

A) Parts of the upper, lower electrode pads 124 A, 124 B are disposed outside an outer edge part 122 d of the top disposed part 122 a . However, the upper, lower electrode pad 24 A, 24 B are entirely disposed inside the outer edge part 22 d.

B) The upper, lower electrode pads 124 A, 124 B have parts being in contact with the side disposed parts 122 b respectively. However, the upper, lower electrode pad 24 A, 24 B are formed without being contact with the side disposed parts 22 b , and they do not have parts being in contact with the side disposed parts 22 b.

C) Long-pad length L 124 of the upper, lower electrode pads 124 A, 124 B is longer than the short-pad length W 124 of the upper, lower electrode pads 124 A, 124 B. However, long-pad length L 24 of the upper, lower electrode pads 24 A, 24 B is shorter than the short-pad length W 24 of the upper, lower electrode pads 24 A, 24 B (L 24 <W 24 ).

D) Outer end surfaces 124 AS, 124 BS have parts formed outside the outer edge part 122 d , and they have parts formed outside than the upper, lower through holes 123 A, 123 B. However, outer end surfaces 24 AS, 24 BS are entirely disposed inside the outer edge part 22 d , and they are disposed inside the upper, lower through holes 23 A, 23 B.

E) The upper, lower electrode pads 124 A, 124 B are formed in size larger than the upper, lower through holes 123 A, 123 B. However, the upper, lower electrode pad 24 A, 24 B are formed in size smaller than the upper, lower through holes 23 A, 23 B.

F) The upper, lower electrode pads 124 A, 124 B are in contact with the exposed surface of the upper, lower electrode film 121 b , 121 c inside the through holes 123 A, 123 B. However, the upper, lower electrode pad 24 A, 24 B are in contact with only a part of the inside exposed surface 21 bb , 21 aa.

As described above, the thin-film piezoelectric material elements 12 b is different in structures of the upper, lower through holes 23 A, 23 B, the upper, lower electrode pad 24 A, 24 B and the surface layer insulating film 22 respectively.

By the way, the active length AL is decided by the length of long-side direction of the part which existing part in the pad region 25 and OVL in FIG. 6 are removed from the laminated structure part 121 . The OVL is corresponding to the part which the flexure substrate 4 , the laminated structure part 21 and top disposed part 22 a of the surface layer insulating film 22 are overlaid. There is no great difference between the laminated structure part 21 and the laminated structure part 121 about length of part existing in the pad region 25 , 125 and length of OVL. However, respective active length AL and ALX are different as follows.

In the conventional thin-film piezoelectric material elements 112 b , the upper, lower electrode pad 124 A, 124 B are extended from the through holes 123 A, 123 B to upper side of the long-side disposed parts 122 c through the side disposed parts 122 b . And as illustrated in FIG. 26 , part, of the upper, lower electrode pad 124 A, 124 B, on the long-side disposed parts 122 c (projected part 124 AX, 124 BX) are connected to the suspension pad 26 .

On the other hand, in the thin-film piezoelectric material elements 12 b , the upper, lower through holes 23 A, 23 B, the upper, lower electrode pads 24 A, 24 B and the surface layer insulating film 22 are provided, parts connected with the suspension pad 26 are the upper, lower electrode pads 24 A, 24 B.

Then, the upper, lower electrode pads 24 A, 24 B are disposed inside the outer edge part 22 d , and they are out of contact with the side disposed parts 22 b , they are entirely disposed inside the top disposed part 22 a . Further, as illustrated in FIG. 23 ( a ) , FIG. 23 ( b ) , the length 25 X, of the pad region 25 and long-side disposed parts 22 c along the long-side direction of the thin-film piezoelectric material elements 12 b , are greatly shortened as compared with the length 125 X of the pad region 125 and long-side disposed parts 122 c , and lengths along the long-side direction of the upper, lower electrode pads 24 A, 24 B are also greatly shortened as compared with conventional one.

Therefore, a space along the long-side direction of the thin-film piezoelectric material elements 12 b is larger than a space along the long-side direction of the thin-film piezoelectric material elements 112 b , thereby the length of the laminated structure part 21 along the long-side direction can be made longer than the length of the laminated structure part 121 along the long-side direction.

Accordingly, in the thin-film piezoelectric material elements 12 b , the active length is extended than the conventional thin-film piezoelectric material elements 112 b , the active length AL can be made longer than the active length ALX. Therefore, the stroke of the thin-film piezoelectric material elements 12 b is increased than the stroke of the thin-film piezoelectric material elements 112 b.

Further, concerning the upper, lower electrode pad 24 A, 24 B, the long-pad lengths L 24 of them are shorter than the short-pad lengths W 24 . Because this is effective for shortening the space of the thin-film piezoelectric material elements 12 b along the long-side direction, the space of the thin-film piezoelectric material elements 12 b along the long-side direction is further extended, thereby the active length is further extended.

Further, the outer end surfaces 24 AS, 24 BS of the upper, lower electrode pads 24 A, 24 B are entirely flat, and they do not have bending parts like the upper, lower electrode pads 124 A, 124 B. If the bending parts exist like the upper, lower electrode pads 124 A, 124 B, existence of the parts on the side disposed part 122 b bring difficulty about approach of the thin-film piezoelectric material elements 112 b to the suspension pad 26 , thereby space extension of the thin-film piezoelectric material elements 112 b along the long-side direction is difficult.

However, in case of the thin-film piezoelectric material elements 12 b , the outer end surfaces 24 AS, 24 BS are entirely flat, and upper, lower electrode pads 24 A, 24 B do not have bending parts. Therefore, the thin-film piezoelectric material elements 12 b is able to be approached, space extension of the thin-film piezoelectric material elements 12 b along the long-side direction is able to be executed.

Further, in case of the thin-film piezoelectric material elements 12 b , long-side length L 22 c of the long-side disposed parts 22 c is shorter than the long-side length L 23 of the upper through hole 23 A. Therefore, the thin-film piezoelectric material elements 12 b is able to be more approached, the length of the thin-film piezoelectric material elements 12 b is able to be extended. This brings further space extension of the thin-film piezoelectric material elements 12 b along the long-side direction.

On the other hand, as illustrated in FIG. 21( a ) , the conventional thin-film piezoelectric material elements 190 , having a piezoelectric material film 141 , flat flexure substrate 144 and a base insulating layer 145 has a problem in which the stroke escape in a bending direction. Therefore, as illustrated in FIG. 21( b ) , the thin-film piezoelectric material elements 191 , having the base insulating layer 155 instead of the base insulating layer 145 , is conventionally known. A cavity 156 is formed in the base insulating layer 155 .

Then, as illustrated in FIG. 22( a ) , the stroke of the thin-film piezoelectric material elements 190 is the size that subtract reduced amount with bending of the piezoelectric material film 141 from 2Δ (two times of Δ) when the piezoelectric material film 141 is flat. Further, as illustrated in FIG. 22( a ) , the stroke of the thin-film piezoelectric material elements 191 is the size that subtract reduced amount with bending of the piezoelectric material film 141 from 2Δ+2h Sin θ, when the piezoelectric material film 141 is flat.

The thin-film piezoelectric material elements 191 has an effect by improvement of escaping stroke in bending direction, but length of the piezoelectric material film 141 is the same with the thin-film piezoelectric material elements 191 , so there is no difference about active length.

On the other hand, in case of the thin-film piezoelectric material elements 12 b according to the present invention, the long-side length of the laminated structure part 21 is longer than the conventional one, so active length become longer than the conventional one. Accordingly, active length is extended than the conventional one, the stroke is also increased than the conventional one.

Modified Example 1

Subsequently, the thin-film piezoelectric material element 42 b according to the modified example 1 will be explained with reference to FIG. 9 to FIG. 12 . Here, FIG. 9 is a plan view, similar with FIG. 5 , showing the thin-film piezoelectric material element 42 b and the peripheral part according to the modified example 1. FIG. 10 is a sectional view taken along the line 10 - 10 in FIG. 9 , FIG. 11 is a sectional view taken along the line 11 - 11 in FIG. 9 . FIG. 12 is a sectional view, similar with FIG. 10 , showing the thin-film piezoelectric material element 42 b , connected to the suspension pad 26 by the connecting electrode 18 b . Note that the connecting electrode 18 b is omitted in FIGS. 9-11 for convenience of illustration.

The thin-film piezoelectric material element 42 b are different in that it has upper, lower electrode pads 34 A, 34 B instead of upper, lower electrode pads 24 A, 24 B, as compared with the thin-film piezoelectric material element 12 b.

The upper electrode pad 34 A have an inside pad part 34 Aa and outside pad part 34 Ab. The inside pad part 34 Aa and outside pad part 34 Ab are unified.

The inside pad part 34 Aa is formed inside the upper through hole 23 A, but a part of the inside pad part 34 Aa is in contact with the upper through hole 23 A. The inside pad part 34 Aa is formed in the rectangular parallelepiped shape. The inside pad part 34 Aa is directly in contact with the inside exposed surface 21 bb , and disposed entirely inside the outer edge part 22 d . Further, the inside pad part 34 Aa is formed without contact with the side disposed parts 22 b.

The outside pad part 34 Ab is a part which extends outside than the upper through hole 23 A (referred to also extended part). The outside pad part 34 Ab is disposed in the closer position than the inside pad part 34 Aa to the suspension pads 26 . The outside pad part 34 Ab is formed on the surface layer insulating film 22 . The outside pad part 34 Ab is disposed entirely inside the outer edge part 22 d . The outside pad part 34 Ab is formed without contact with the side disposed parts 22 b.

The upper electrode pad 34 A has a long-pad length L 34 and the short-pad length W 24 , it is preferable that the long-pad length L 34 is less than the short-pad length W 24 (L 34 ≦W 24 ).

Further, the upper electrode pad 34 A has an outer end surface 34 AS having rectangular shape in a plan view. As illustrated in FIG. 9 , the fine mesh pattern is drawn in the outer end surface 34 AS. As illustrated in FIG. 10 , the outer end surface 34 AS is a part formed outside the top disposed part 22 a . The outer end surface 34 AS is entirely flat. A part of the outer end surface 34 AS is disposed outside the upper through hole 23 A, but the outer end surface 34 AS is entirely inside the outer edge part 22 d.

As illustrated in FIG. 11 , the lower electrode pad 34 B have an upper pad part 34 Ba and lower pad part 34 Bb. The upper pad part 34 Ba is connected to the top surface of the lower pad part 34 Bb.

The upper pad part 34 Ba have an inside pad part and outside pad part, similar with the upper electrode pad 34 A, the inside pad part and outside pad part are unified. The upper pad part 34 Ba is disposed entirely inside the outer edge part 22 d , similar with the upper electrode pad 34 A. Further, the upper pad part 34 Ba is formed without contact with the side disposed parts 22 b.

The lower pad part 34 Bb penetrates the piezoelectric material film 21 a . The lower pad part 34 Bb is in directly contact with the top surface of the lower electrode film 21 c.

As illustrated in FIG. 12 , the thin-film piezoelectric material elements 42 b , having the above-described structure, is connected to suspension pads 26 , 26 with connecting electrode 18 b . In this case, connecting electrodes 18 b , 18 b connect outer end surfaces 34 AS, 34 BS of the upper, lower electrode pads 34 A, 34 B to suspension pads 26 , 26 , respectively.

The above-described thin-film piezoelectric material elements 42 b has the same the upper, lower through holes 23 A, 23 B with the thin-film piezoelectric material elements 12 b and further it has the upper, lower electrode pads 34 A, 34 B, and the surface layer insulating film 22 .

Parts of the upper, lower electrode pads 34 A, 34 B are extended outside the upper, lower through holes 23 A, 23 B unlike the upper, lower electrode pads 24 A, 24 B, but the upper, lower electrode pads 34 A, 34 B are entirely not in contact with the side disposed parts 22 , and the upper, lower electrode pads 34 A, 34 B are disposed entirely inside the outer edge part 22 d . Therefore, in case of the thin-film piezoelectric material elements 42 b , a space is also able to be secured along the long-side direction, similar with the thin-film piezoelectric material elements 12 b , length of the laminated structure part 21 along the long-side direction can be made longer than a length of the laminated structure part 121 along the long-side direction.

Therefore, the active length of the thin-film piezoelectric material elements 42 b is also extended than the active length of the thin-film piezoelectric material elements 112 b , the active length AL is able to be extended than the conventional active length ALX. Accordingly, the stroke of the thin-film piezoelectric material elements 42 b is increased than the stroke of the thin-film piezoelectric material elements 112 b.

Further, when the long-pad length L 34 of the upper, lower electrode pads 34 A, 34 B is shorter than the short-pad length W 24 , the space of the thin-film piezoelectric material elements 42 b along the long-side direction is further extended, thereby the active length is further extended.

Further, the outer end surfaces 34 AS, 34 BS of the upper, lower electrode pads 34 A, 34 B are flat, and they do not have bending parts. Therefore, the thin-film piezoelectric material elements 42 b is able to be approached to the suspension pad 26 , further space extension of the thin-film piezoelectric material elements 42 b along the long-side direction is able to be executed.

Modified Example 2

Subsequently, the thin-film piezoelectric material element 52 b according to the modified example 2 will be explained with reference to FIG. 13 to FIG. 16 . Here, FIG. 13 is a plan view, similar with FIG. 5 , showing the thin-film piezoelectric material element 52 b and the peripheral part according to the modified example 2. FIG. 14 is a sectional view taken along the line 14 - 14 in FIG. 13 , FIG. 15 is a sectional view taken along the line 15 - 15 in FIG. 13 . FIG. 16 is a sectional view, similar with FIG. 14 , showing the thin-film piezoelectric material element 52 b , connected to the suspension pad 26 by the connecting electrode 18 b . Note that the connecting electrode 18 b is omitted in FIGS. 13-15 for convenience of illustration.

The thin-film piezoelectric material element 52 b are different in that it does not have upper, lower electrode pads 24 A, 24 B, as compared with the thin-film piezoelectric material element 12 b.

However, the connecting electrode 18 b , 18 b are formed directly on the upper, lower electrode film 21 b , 21 c . Thereby, as illustrated in FIG. 16 , the thin-film piezoelectric material element 52 b is connected to the suspension pad 26 .

The thin-film piezoelectric material element 52 b has the same surface layer insulating film 22 as the thin-film piezoelectric material element 12 b . Because, the surface layer insulating film 22 has the long-side disposed parts 22 c , the long-side length L 22 c is shorter than the long-side length L 23 , the thin-film piezoelectric material elements 52 b is able to be approached so as not to be in touch with the suspension pad 26 .

Therefore, the length of the thin-film piezoelectric material element 52 b is able to be extended, the space along the long-side direction of the thin-film piezoelectric material element 52 b is able to be extended, the active length is extended.

Modified Example 3

Subsequently, the thin-film piezoelectric material element 62 b according to the modified example 3 will be explained with reference to FIG. 17 to FIG. 20 . Here, FIG. 17 is a plan view, similar with FIG. 5 , showing the thin-film piezoelectric material element 62 b and the peripheral part according to the modified example 3. FIG. 18 is a sectional view taken along the line 18 - 18 in FIG. 17 , FIG. 19 is a sectional view taken along the line 19 - 19 in FIG. 17 . FIG. 20 is a sectional view, similar with FIG. 19 , showing the thin-film piezoelectric material element 62 b , connected to the suspension pad 26 by the connecting electrode 18 b . Note that the connecting electrode 18 b is omitted in FIGS. 17-19 for convenience of illustration.

The thin-film piezoelectric material element 62 b are different in that it has upper, lower electrode pads 44 A, 44 B instead of upper, lower electrode pads 24 A, 24 B, as compared with the thin-film piezoelectric material element 12 b.

The upper electrode pad 44 A have an inside pad part 44 Aa and outside pad part 44 Ab. The inside pad part 44 Aa and outside pad part 44 Ab are unified.

The inside pad part 44 Aa is formed inside the upper through hole 23 A, further it is in contact with the upper through hole 23 A. The inside pad part 44 Aa is formed in the rectangular parallelepiped shape. The inside pad part 44 Aa is directly in contact with the inside exposed surface 21 bb , and disposed entirely inside the outer edge part 22 d . Further, the inside pad part 44 Aa is formed without contact with the side disposed parts 22 b.

The outside pad part 44 Ab is a part, like flange, which extends outside the upper through hole 23 A. The outside pad part 44 Ab is formed on the surface layer insulating film 22 . However, the outside pad part 44 Ab is disposed entirely inside the outer edge part 22 d . The outside pad part 44 Ab is formed without contact with the side disposed parts 22 b.

The upper electrode pad 44 A has a long-pad length L 44 and a short-pad length W 44 , it is preferable that the long-pad length L 44 is less than the short-pad length W 44 (L 44 ≦W 44 ).

Further, the upper electrode pad 44 A has an outer end surface 44 AS having rectangular shape in a plan view. As illustrated in FIG. 17 , the fine mesh pattern is drawn in the outer end surface 44 AS. As illustrated in FIG. 18 , the outer end surface 44 AS is a part formed outside the top disposed part 22 a . The outer end surface 44 AS is entirely flat. A part of the outer end surface 44 AS is disposed outside the upper through hole 23 A, but the outer end surface 44 AS is entirely inside the outer edge part 22 d.

As illustrated in FIG. 19 , the lower electrode pad 44 B have an upper pad part 44 Ba and lower pad part 44 Bb. The upper pad part 44 Ba is connected to the top surface of the lower pad part 44 Bb.

The upper pad part 44 Ba have an inside pad part and outside pad part, similar with the upper electrode pad 44 A, the inside pad part and outside pad part are unified. The upper pad part 44 Ba is disposed entirely inside the outer edge part 22 d , similar with the upper electrode pad 44 A. Further, the upper pad part 44 Ba is formed without contact with the side disposed parts 22 b.

The lower pad part 44 Bb penetrates the piezoelectric material film 21 a . The lower pad part 44 Bb is in directly contact with the top surface of the lower electrode film 21 c.

As illustrated in FIG. 20 , the thin-film piezoelectric material elements 62 b , having the above-described structure, is connected to suspension pads 26 , 26 with connecting electrode 18 b . In this case, connecting electrodes 18 b , 18 b connect outer end surfaces 44 AS, 44 BS of the upper, lower electrode pads 44 A, 44 B to suspension pads 26 , 26 , respectively.

The above-described thin-film piezoelectric material elements 62 b has the upper, lower through holes 23 A, 23 B, the upper, lower electrode pads 44 A, 44 B, and the surface layer insulating film 22 .

Parts of the upper, lower electrode pads 44 A, 44 B are extended outside the upper, lower through holes 23 A, 23 B unlike the upper, lower electrode pads 24 A, 24 B, but the upper, lower electrode pads 44 A, 44 B are entirely not in contact with the side disposed parts 22 , and the upper, lower electrode pads 44 A, 44 B are disposed entirely inside the outer edge part 22 d . Therefore, in case of the thin-film piezoelectric material elements 62 b , a space is also able to be secured along the long-side direction, similar with the thin-film piezoelectric material elements 12 b , length of the laminated structure part 21 along the long-side direction can be made longer than a length of the laminated structure part 121 along the long-side direction.

Therefore, the active length of the thin-film piezoelectric material elements 62 b is also extended than the active length of the thin-film piezoelectric material elements 112 b , the active length AL is able to be extended than the conventional active length ALX. Accordingly, the stroke of the thin-film piezoelectric material elements 62 b is increased than the stroke of the thin-film piezoelectric material elements 12 b.

Further, when the long-pad length L 44 of the upper, lower electrode pads 44 A, 44 B is shorter than the short-pad length W 44 , the space of the thin-film piezoelectric material elements 62 b along the long-side direction is further extended, thereby the active length is further extended.

Further, the outer end surfaces 44 AS, 44 BS of the upper, lower electrode pads 44 A, 44 B are flat, and they do not have bending parts. Therefore, the thin-film piezoelectric material elements 62 b is able to be approached, further space extension of the thin-film piezoelectric material elements 62 b along the long-side direction is able to be executed.

(Embodiments of Hard Disk Drive)

Next, embodiments of the hard disk drive will now be explained with reference to FIG. 27 .

FIG. 27 is a perspective view illustrating a hard disk drive 201 equipped with the above-mentioned HGA 1 . The hard disk drive 201 includes a hard disk (magnetic recording medium) 202 rotating at a high speed and the HGA 1 . The hard disk drive 201 is an apparatus which actuates the HGA 1 , so as to record/reproduce data onto/from recording surfaces of the hard disk 202 . The hard disk 202 has a plurality of ( 4 in the drawing) platters. Each platter has a recording surface opposing its corresponding the head slider 60 .

The hard disk drive 201 positions the head slider 60 on a track by an assembly carriage device 203 . A thin-film magnetic head, not illustrated, is formed on this head slider 60 . Further, the hard disk drive 201 has a plurality of drive arms 209 . The drive arms 209 pivot about a pivot bearing shaft 206 by means of a voice coil motor (VCM) 205 , and are stacked in a direction along the pivot bearing shaft 206 . Further, the HGA 1 is attached to the tip of each drive arm 209 .

Further, the hard disk drive 201 has a control circuit 204 controlling recording/reproducing.

In the hard disk drive 201 , when the HGA 1 is rotated, the head slider 60 moves in a radial direction of the hard disk 202 , i.e., a direction traversing track lines.

In case such hard disk drive 201 are formed with the above-described thin-film piezoelectric material elements 12 a , 12 b , because the extension of the active length brings the increase of the stroke, minute adjustment for position of the thin-film magnetic head is able to be executed accurately.

This invention is not limited to the foregoing embodiments but various changes and modifications of its components may be made without departing from the scope of the present invention. Besides, it is clear that various embodiments and modified examples of the present invention can be carried out on the basis of the foregoing explanation. Therefore, the present invention can be carried out in modes other than the above-mentioned best modes within the scope equivalent to the following claims.