Head suspension assembly and disc device

Abstract

Provided are a head suspension assembly and a disc device in which the reliability of electrical connection is improved while short-circuiting of an electrode is suppressed. According to an embodiment, the head suspension assembly includes a support plate, a wiring member (40) disposed on the support plate, a head mounted on the wiring member, and a piezoelectric element (50) mounted on the wiring member. The wiring member includes a metal plate (44a) fixed to the support plate, a base insulating layer (44b), a conductive layer (44c) in which a first connection pad, a second connection pad (70b), and a plurality of wirings are formed on the base insulating layer, and a cover insulating layer (44d) laminated on the conductive layer. The base insulating layer has a first recess (HE2) formed in a region opposite to an end portion of the piezoelectric element in the vicinity of the second connection pad, and the cover insulating layer has a recess recessed along the first recess and an opening portion (OPl) provided in the recess. The piezoelectric element is connected to the second connection pad by a conductive adhesive (Ad), and a portion of the conductive adhesive is filled in the recess and the opening portion of the cover insulating layer.

Description

[0001] This application takes priority of Japanese Patent Application No. 2021-125386 (Filing date: July 30, 2021). This application includes the entire contents of the base application by reference to the base application. TECHNICAL FIELD

[0002] Embodiments of the present application relate to a head suspension assembly and a disk device provided with the head suspension assembly. BACKGROUND

[0003] As a disk device, for example, a hard disk drive (HDD) is provided with a plurality of disks disposed in a housing in a rotatable manner, a plurality of heads that read and write information from and to the disks, and a head actuator that supports the heads in a movable manner with respect to the disks.

[0004] The head actuator has a plurality of head suspension assemblies that support the heads at the front end portions. The head suspension assembly has a base plate fixed at one end to an arm, a load beam extending from the base plate, and a flexible member (wiring member) provided on the load beam and the base plate. The head is supported at a gimbal portion of the flexible member.

[0005] In recent years, a head suspension assembly having a piezoelectric element that constitutes a micro actuator has been proposed. The piezoelectric element is mounted to the flexible member. The electrode of the piezoelectric element is electrically and mechanically connected to a conductor pattern, for example, a conductive land of the flexible member, for example, by a conductive adhesive. SUMMARY

[0006] The present application has been made to solve the problem of providing a head suspension assembly and a disk device in which the reliability of electrical connection is improved while suppressing short circuit of the electrode of the piezoelectric element.

[0007] According to the embodiment, the head suspension assembly is provided with a support plate, a wiring member provided on the support plate, a head mounted to the wiring member, and a piezoelectric element mounted to the wiring member and capable of stretching and contracting. The wiring member is provided with a metal plate fixed to the support plate, and a laminated member having a first insulating layer, a conductive layer laminated on the first insulating layer, a second insulating layer laminated on the conductive layer, at least one pair of connection lands formed of the conductive layer, and a plurality of wirings connected to the connection lands. The connection lands are provided in a recess formed in the first insulating layer, a recess is formed along the recess, the covering insulating layer has an opening opposite to the connection lands, and the piezoelectric element is connected to the connection lands by a conductive adhesive filled in the opening and the recess of the connection lands. BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1is an exploded perspective view of a hard disk drive (HDD) of Embodiment 1.

[0009] Figure 2 is a plan view of a head suspension assembly of the HDD.

[0010] Figure 3 is a plan view of a front end portion of the head suspension assembly, shown enlarged.

[0011] Figure 4 is an exploded perspective view showing a land portion and a piezoelectric element of a flexure of the head suspension assembly.

[0012] Figure 5 is a plan view showing the land portion and the piezoelectric element of the flexure.

[0013] Figure 6 is a cross-sectional view of the land portion and the piezoelectric element along line A-A of Figure 5

[0014] Figure 7 is a cross-sectional view of the land portion and the piezoelectric element along line B-B of Figure 5

[0015] Figure 8 is a cross-sectional view of a land portion and a piezoelectric element of an HDD of Embodiment 2.

[0016] Figure 9 is a cross-sectional view of a land portion and a piezoelectric element of an HDD of Embodiment 3.

[0017] Figure 10 is a cross-sectional view of a land portion and a piezoelectric element of an HDD of Embodiment 4.

[0018] Explanation of Reference Numerals

[0019] 10... housing, 12... base, 12a... bottom wall, 12b... side wall, 17... magnetic head, 18... magnetic disk, 19... spindle motor, 22... actuator assembly, 30... suspension assembly, 36... gimbaling portion (elastic support portion), 40... flexure (wiring member), 44a... metal plate, 44b... base insulating layer, 44c... conductive layer, 44d... cover insulating layer, 44e... second cover insulating layer, 45b... drive wire, 50... piezoelectric element, 54... first electrode, 56... second electrode, 70a... first connection land, 70b... second connection land, HE1, HE2... recess (etching region), OP1... opening portion, Ad... conductive adhesive DETAILED DESCRIPTION

[0020] Hereinafter, a disk device of an embodiment will be described with reference to the drawings.

[0021] ​​Further, the disclosure is nothing but an example, and appropriate changes that can be easily conceived by those skilled in the art while maintaining the gist of the application are of course included in the scope of the present application. In addition, the drawings are schematically shown with respect to the size, shape, etc. of each portion in order to make the explanation more clear, but are nothing but an example, and do not limit the explanation of the present application. In addition, in the present specification and each drawing, the same reference numerals are attached to the same elements as those described with respect to the already appeared drawings, and sometimes the detailed explanation is appropriately omitted.

[0022] (First Embodiment)

[0023] As the disk device, a hard disk drive (HDD) of the first embodiment will be described in detail.

[0024] Figure 1 is an exploded perspective view of the HDD of the first embodiment shown with the cover removed. As shown in the drawing, the HDD is provided with a rectangular housing 10. The housing 10 has a rectangular box-shaped base 12 with an upper surface opening and a cover (top cover) 14. The base 12 has a rectangular bottom wall 12a and a side wall 12b provided upright along the periphery of the bottom wall 12a, for example, integrally formed of aluminum. The cover 14 is formed in a rectangular plate shape, for example, of stainless steel. The cover 14 is threadedly fastened to the side wall 12b of the base 12 by a plurality of screws 13, and hermetically closes the upper portion opening of the base 12.

[0025] Within the housing 10, a plurality of, for example, five disks 18 as disk-shaped recording media and a spindle motor 19 that supports the disks 18 and rotates the disks 18 are provided. The spindle motor 19 is disposed on the bottom wall 12a.

[0026] Each disk 18 is formed in a circular plate shape, for example, with a diameter of 95 mm (3.5 inches), and has a magnetic recording layer on its upper surface and / or lower surface. The disks 18 are coaxially fitted to an unillustrated hub of the spindle motor 19, and are fixed to the hub by a clamping spring 20. The disks 18 are supported in a state of being located in parallel with the bottom wall 12a of the base 12. The plurality of disks 18 are rotated at a predetermined rotational speed by the spindle motor 19.

[0027] Further, the number of the disks 18 is not limited to five, and can be increased or decreased. In addition, it can be that a single disk 18 is housed within the housing 10.

[0028] Within the housing 10, a plurality of magnetic heads 17 (refer to FIG. 2) that record and reproduce information on the disks 18 are provided. The magnetic heads 17 are disposed on the side wall 12b of the base 12. Figure 2) and a head actuator 22 that supports these magnetic heads 17 in a manner that is movable with respect to the magnetic disk 18. In addition, a voice coil motor (VCM) 24 that rotates and positions the head actuator 22, a ramp loading mechanism 25 that holds the magnetic heads 17 in an unloading position away from the magnetic disk 18 when the magnetic heads 17 are moved to the outermost periphery of the magnetic disk 18, and a substrate unit (FPC unit) 21 on which electronic components such as a transducer connector are mounted are provided in the housing 10.

[0029] The head actuator 22 has an actuator block 29 in which a bearing unit 28 is built in, a plurality of arms 32 that extend from the actuator block 29, and a suspension assembly 30 that extends from each arm 32 (there are cases in which this is also referred to as a head gimbal assembly (HGA)). The magnetic head 17 is supported at the front end of each suspension assembly 30. The head actuator 22 is supported in a manner that is rotatable with respect to a pivot that is erected on the bottom wall 12a via the bearing unit 28.

[0030] A printed circuit substrate that is not shown is threadedly fastened to the outer surface of the bottom wall 12a. The printed circuit substrate is provided with a control section that controls the operation of the spindle motor 19, and controls the operation of the VCM 24 and the magnetic head 17 via the substrate unit 21.

[0031] Next, the structure of the suspension assembly 30 will be described in detail.

[0032] Figure 2 is a plan view of the head suspension assembly.

[0033] As shown in Figure 2 , each suspension assembly 30 has a suspension 34 that extends from the arm 32, and the magnetic head 17 is mounted at the front end of the suspension 34. In addition, the magnetic head 17 and the suspension assembly 30 that supports the magnetic head 17 are collectively referred to as a head suspension assembly.

[0034] The suspension 34 that functions as a support plate has a rectangular base piece 42 that is formed from a metal plate that is several hundred micrometers thick, and an elongated leaf spring-shaped load beam 35 that is formed from a metal plate that is several tens of micrometers thick. The base end of the load beam 35 is arranged in overlapping relation to the front end of the base piece 42, and the load beam 35 is fixed to the base piece 42 by welding at a plurality of points. The width of the base end of the load beam 35 is formed to be substantially equal to the width of the base piece 42. A tab 46 that is rod-shaped is provided protruding from the front end of the load beam 35.

[0035] The base piece 42 has a circular opening 42a at the base end thereof, and a circular ring-shaped protrusion 43 that is located around the opening. The base piece 42 is fastened and joined to the front end of the arm 32 by fitting the protrusion 43 into the rivet hole of the arm 32 and riveting the protrusion 43. The base end of the base piece 42 can also be fixed to the front end of the arm 32 by laser welding, spot welding, or adhesion.

[0036] The suspension assembly 30 includes a thin and long ribbon-shaped flexure (wiring member) 40 for transmitting recording and reproducing signals and driving signals of the piezoelectric element 50, and a pair of piezoelectric elements (for example, PZT elements) 50 mounted on the flexure 40. Figure 2 As shown, the front end portion 40a of the flexure 40 is disposed on the load beam 35 and the substrate 42, while the rear half (extension) 40b extends outward from the side edge of the substrate 42 and extends along the side edge of the arm 32. The connection end 40c at the front end of the extension 40b has a plurality of connection pads 40f. These connection pads 40f are connected to the main FPC of the substrate unit 21 described above.

[0037] Figure 3 It is a plan view showing the front end portion of the suspension assembly 30 in an enlarged manner.

[0038] As shown in the figure, the front end of the flexure 40 is located on the front end of the load beam 35, forming a gimbal portion 36 that functions as an elastic support portion. The magnetic head 17 is mounted and fixed on the gimbal portion 36 and supported by the load beam 35 via the gimbal portion 36. A pair of piezoelectric elements 50 serving as driving elements are mounted on a mounting portion 60 of the gimbal portion 36, and are located on the base end side of the load beam 35 relative to the magnetic head 17.

[0039] The flexure 40 comprises a thin metal plate (metal plate) 44a such as stainless steel as a base, and a strip-shaped laminated member 41 bonded or fixed to the thin metal plate 44a, forming a long and narrow laminated plate. The laminated member 41 comprises a base insulating layer (first insulating layer) 44b, most of which is fixed to the thin metal plate 44a; a conductive layer (wiring pattern) 44c formed on the base insulating layer 44b and constituting a plurality of signal wirings 45a, drive wirings 45b, and a plurality of connection pads; and a cover insulating layer (second insulating layer) 44d (see FIG. 1 ) laminated on the base insulating layer 44b to cover the conductive layer 44c. Figure 6 ) As the conductive layer 44c, for example, copper foil can be used.

[0040] In the universal joint portion 36 of the flexible member 40, the metal sheet 44a has a rectangular tongue portion (support portion) 36a located on the front end side, a roughly rectangular base end portion (base end plate portion) 36b located on the base end side with a space between the tongue portion 36a and the base end portion, a pair of slender outward beams (connecting rod portions) 36c extending from the tongue portion 36a to the base end portion 36b, and a pair of handles (support protrusions) 36f protruding from the two side edges of the tongue portion 36a to its two sides.

[0041] The base end portion 36b is bonded to the surface of the load beam 35 or fixed to the surface of the load beam 35 by spot welding. The tongue portion 36a is formed in a size and shape capable of accommodating the magnetic head 17, for example, in a substantially rectangular shape. The tongue portion 36a is arranged so that the center axis in the width direction thereof coincides with the center axis C of the suspension 34. Further, the substantially central portion of the tongue portion 36a abuts against a recess (projection) 48 provided at the front end portion of the load beam 35. The tongue portion 36a is elastically deformable in various directions by a pair of outrigger beams 36c. Thus, the tongue portion 36a and the magnetic head 17 are displaced in response to the surface of the disk 18 so as to follow the roll and pitch directions flexibly, and a minute gap can be maintained between the surface of the disk 18 and the magnetic head 17.

[0042] In the gimbal portion 36, a portion of the laminated member 41 of the flexure 40 is divided into two and located on both sides of the center axis C of the suspension 34. The laminated member 41 has a base end portion 47a fixed to the base end portion 36b of the metal plate 44a, a front end portion 47b bonded to the tongue portion 36a, a pair of first bridge portions 47c in the form of strips extending from the base end portion 47a to the front end portion 47b, and a pair of second bridge portions 47d in the form of strips extending from the base end portion 47a to the middle of the first bridge portions 47c in parallel with the first bridge portions 47c and merging into the first bridge portions 47c. The first bridge portions 47c are located on both sides of the tongue portion 36a in parallel with the outrigger beams 36c and extend along the length direction of the load beam 35. Further, the first bridge portions 47c extend over the handle 36f and the cross bars of the outrigger beams 36c and are partially fixed thereto. A portion of each first bridge portion 47c constitutes a mounting portion 60 in which a piezoelectric element 50 is mounted.

[0043] The magnetic head 17 is fixed to the tongue portion 36a by an adhesive. The magnetic head 17 is arranged so that the center axis in the length direction thereof coincides with the center axis of the suspension 34, and further, the substantially central portion of the magnetic head 17 is located on the recess 48. The recording and reproducing elements of the magnetic head 17 are electrically joined to a plurality of connection pads 40d of the front end portion 47b by a conductive adhesive such as solder or silver paste. Thus, the magnetic head 17 is connected to the signal wiring 45a via the connection pads 40d.

[0044] The mounting portion 60 and the piezoelectric element 50 will be described in detail.

[0045] Figure 4 is an exploded perspective view showing the mounting portion and the piezoelectric element of the flexure 40, Figure 5 is a plan view of the mounting portion in which the piezoelectric element is mounted, Figure 6 is a sectional view of the mounting portion and the piezoelectric element along the line A-A of Figure 5 .

[0046] As shown in Figure 4 and Figure 6As shown, the flexure 40 comprises a thin metal plate (metal plate) 44a, such as stainless steel, as a base, and a strip-shaped laminate member 41 bonded or fixed to the metal plate 44a, forming a long and narrow laminate. The laminate member 41 comprises a base insulating layer (first insulating layer) 44b, most of which is fixed to the metal plate 44a; a conductive layer (wiring pattern) 44c formed on the base insulating layer 44b and constituting a plurality of signal wirings 45a, drive wirings 45b, and a plurality of connection pads; and a cover insulating layer (second insulating layer) 44d laminated on the base insulating layer 44b to cover the conductive layer 44c. For example, copper foil can be used as the conductive layer 44c.

[0047] The mounting portion 60 includes a first connection pad 70a and a second connection pad 70b, each formed from a conductive layer 44c. The first connection pad 70a and the second connection pad 70b are each electrically connected to a drive wiring 45b formed from the conductive layer 44c. The first connection pad 70a and the second connection pad 70b are arranged parallel to the central axis C of the load beam 35 with a predetermined spacing therebetween. In this embodiment, the first bridge portion 47c of the flexure 40 is interrupted between the first connection pad 70a and the second connection pad 70b. As a result, the first connection pad 70a and the second connection pad 70b are arranged with a predetermined spacing therebetween.

[0048] In the insulating cover layer 44d stacked on the conductive layer 44c, openings 72a and 72b are provided at positions overlapping the first and second connecting pads 70a and 70b, respectively. Most of the first and second connecting pads 70a and 70b are exposed to the outer surface of the insulating cover layer 44d through the openings 72a and 72b, respectively. In one example, the first and second connecting pads 70a and 70b are each formed in a rectangular shape, and similarly, the openings 72a and 72b are formed in a rectangular shape slightly smaller than the connecting pads.

[0049] like Figure 4 and Figure 6 As shown, in one example, the piezoelectric element 50 includes a first piezoelectric substrate 51a and a second piezoelectric substrate 51b formed into a flat rectangular parallelepiped shape from a piezoelectric material, and a first electrode 54 and a second electrode 56 for applying voltage to the piezoelectric substrates 51a and 51b. The longitudinal direction of the piezoelectric element 50 is designated as X, and the width direction perpendicular thereto is designated as Y. In this embodiment, the piezoelectric element 50 further includes a restraining layer 52 for restraining the deflection of the first and second piezoelectric substrates 51a and 51b. The restraining layer 52 is formed to have a size substantially equal to that of the first and second piezoelectric substrates 51a and 51b and is laminated on the second piezoelectric substrate 51b. Examples of piezoelectric materials include lead zirconate titanate and ceramics. In one example, the restraining layer 52 is formed from the same piezoelectric material as the piezoelectric substrates 51a and 51b. The restraining layer 52 is not limited to piezoelectric materials and may also be formed from other materials.

[0050] The rectangular parallelepiped formed by the laminated first piezoelectric substrate 51a, second piezoelectric substrate 51b, and tie layer 52 has the first main surface S1 which becomes a lower surface, the sixth main surface S6 which becomes an upper surface, side surfaces SS1, SS2 which are opposite each other on the short side, and side surfaces SL1, SL2 which are opposite each other on the long side. The first piezoelectric substrate 51a has the first main surface (lower surface) S1 described above, and the second main surface S2 which is opposite the first main surface S1. The second piezoelectric substrate 51b has the third main surface S3 which is opposite the second main surface S2 of the first piezoelectric substrate 51a, and the fourth main surface S4 which is on the side opposite the third main surface S3. Further, the tie layer 52 has the fifth main surface S5 which is opposite the fourth main surface S4 of the second piezoelectric substrate 51b, and the sixth main surface (upper surface) S6 described above which is on the side opposite the fifth main surface S5.

[0051] The first electrode 54 integrally has a first electrode portion 54a which is provided on one end portion of the length direction X of the first main surface S1, a second electrode portion 54b which is provided on the side surface SS1, a third electrode portion 54c which is provided on the second main surface S2 and which extends from the one side surface SS1, that is, from the second electrode portion 54b, to the vicinity of the other side surface SS2, and a fourth electrode portion 54d which is provided on the sixth main surface S6 and which extends from the one side surface SS1, that is, from the second electrode portion 54b, to the vicinity of the other side surface SS2. The width of the width direction Y of the first electrode 54 is formed to be the same as the width of the piezoelectric substrates 51a, 51b and the tie layer 52, and the both side edges of the first electrode 54 are aligned with the side surfaces SL1, SL2 on the long side, and are exposed on these side surfaces SL1, SL2. In addition, the end edge of the first electrode portion 54a extends substantially in parallel with the side surface SS1. The first electrode 54 is formed on the surface of the piezoelectric substrate 51a and the tie layer 52 by sputtering, chemical vapor deposition (CVD), spin coating, or the like.

[0052] The second piezoelectric substrate 51b is provided so as to overlap the second main surface S2 and the third electrode portion 54c of the first piezoelectric substrate 51a. One end portion of the second piezoelectric substrate 51b is connected to the first piezoelectric substrate 51a between the extended end of the third electrode portion 54c and the side surface SS2.

[0053] On the other hand, the second electrode 56 integrally has a fifth electrode portion 56a provided on the first main surface S1, a sixth electrode portion 56b provided on the side surface SS2, a seventh electrode portion 56c provided on the fourth main surface S4 of the second piezoelectric substrate 51b and extending from the side surface SS2 on one side, that is, from the sixth electrode portion 56b to the vicinity of the side surface SS1 on the other side, and an eighth electrode portion 56d provided on the sixth main surface S6 and extending from the side surface SS2 on one side, that is, from the sixth electrode portion 56b to the vicinity of the fourth electrode portion 54d. The width of the second electrode 56 in the width direction Y is formed to be the same as the width of the piezoelectric substrates 51a and 51b, and both side edges of the second electrode 56 are located at positions aligned with both side surfaces SL1 and SL2 of the piezoelectric element 50 and are exposed at both side surfaces SL1 and SL2. The second electrode 56 is formed on the surfaces of the piezoelectric substrates 51a and 51b and the tie layer 52 by sputtering, chemical vapor deposition (CVD), spin coating, or the like.

[0054] The fifth electrode portion 56a extends from the vicinity of the first electrode portion 54a to the side surface SS2 and covers substantially the entire first main surface S1. In the first main surface S1, an end edge of the fifth electrode portion 56a extends substantially in parallel with the side surface SS1 and opposes an end edge of the first electrode portion 54a with a gap G1 interposed therebetween. The fifth electrode portion 56a opposes the third electrode portion 54c substantially in parallel with the third electrode portion 54c with the first piezoelectric substrate 51a interposed therebetween.

[0055] The seventh electrode portion 56c opposes the third electrode portion 54c substantially in parallel with the third electrode portion 54c with the second piezoelectric substrate 51b interposed therebetween. The eighth electrode portion 56d extends on the sixth main surface S6 from the side surface SS2 to the vicinity of the fourth electrode portion 54d. An end edge of the eighth electrode portion 56d extends substantially in parallel with the side surface SS2 and opposes an end edge of the fourth electrode portion 54d with a gap G2 interposed therebetween.

[0056] The tie layer 52 is provided in overlapping relation to the fourth main surface S4 of the second piezoelectric substrate 51b and the seventh electrode portion 56c. One end portion of the tie layer 52 is connected to the second piezoelectric substrate 51b between the extended end of the seventh electrode portion 56c and the side surface SS1.

[0057] As Figure 4 , Figure 5 , Figure 6As shown, the piezoelectric element 50 configured as described above is arranged on the mounting portion 60 of the flexible member 40 in a state where the first main surface S1 side of the first piezoelectric substrate 51a opposes the mounting portion 60 and in a state where the first electrode portion 54a of the first electrode 54 opposes the first connection pad 70a and the fifth electrode portion 56a of the second electrode 56 opposes the second connection pad 70b. The first electrode portion 54a and the first connection pad 70a are electrically and mechanically connected by the conductive adhesive material Ad filled between the first electrode portion 54a and the first connection pad 70a. The fifth electrode portion 56a and the second connection pad 70b are electrically and mechanically connected by the conductive adhesive material Ad filled between the end portion on the side surface SS2 side of the fifth electrode portion 56a and the second connection pad 70b.

[0058] Thus, the piezoelectric element 50 is mounted on the mounting portion 60 of the flexible member 40 and connected to the drive wiring 45b via the first connection pad 70a and the second connection pad 70b. The piezoelectric element 50 is arranged so that the length direction X extends substantially in parallel with the central axis C of the suspension 34.

[0059] For example, the second electrode 56 is connected to the ground via the second connection pad 70b. A drive voltage is applied to the first electrode 54 via the drive wiring 45b and the first connection pad 70a. If the drive voltage is applied, a voltage is applied between the third electrode portion 54c of the first electrode 54 and the fifth electrode portion 56a of the second electrode 56, and acts on the first piezoelectric substrate 51a located between these electrode portions. In addition, if the drive voltage is applied, a voltage is applied between the third electrode portion 54c of the first electrode 54 and the seventh electrode portion 56c of the second electrode 56, and acts on the second piezoelectric substrate 51b located between these electrode portions.

[0060] The first piezoelectric substrate 51a and the second piezoelectric substrate 51b perform a stretching and contracting action in the length direction X if a voltage is applied. Further, along with the stretching and contracting action of the piezoelectric substrates 51a, 51b, the piezoelectric substrates 51a, 51b are deformed in a manner to generate bending or flexing, but the bending or flexing is suppressed by the binding layer 52, and the piezoelectric substrates 51a, 51b are bound in a flat state. Thus, the amount of stretching and contracting, that is, the amount of action, in the length direction X of the piezoelectric substrates 51a, 51b can be ensured.

[0061] According to the present embodiment, each mounting portion 60 of the flexible member 40 has a recess (etching region) provided on both sides of the width direction Y of the first connection pad 70a and a recess (etching region) provided on both sides of the width direction Y of the second connection pad 70b.

[0062] Figure 7 is a cross-sectional view of the mounting portion and the piezoelectric element along the line B-B of Figure 5 ​

[0063] As Figure 4 and Figure 7 shown, in the mounting portion on the side of the second connection pad 70b, a recess (second recess) HE1 is formed in the metal plate 44a of the flexible member 40. The recess HE1 is formed, for example, by reducing the plate thickness to about 1 / 2 or so by half-etching a portion of the metal plate 44a. The recess HE1 is formed, for example, in a substantially rectangular shape on both sides in the width direction Y of the second connection pad 70b. Also, the two recesses HE1 are located at positions opposite the both end portions in the width direction Y of the piezoelectric element 50.

[0064] A portion of the base insulating layer 44b laminated to the metal plate 44a is formed overlapping the recess HE1 and is recessed along the recess HE1, forming a recess one level lower. A recess (first recess) HE2 is further formed in the base insulating layer 44b. The recess HE2 is formed by reducing the layer thickness to about 1 / 2 or so by half-etching a portion of the base insulating layer 44b. The recess HE2 is formed, for example, in a substantially rectangular shape on both sides in the width direction Y of the second connection pad 70b. Also, the two recesses HE2 are located at positions opposite the both end portions in the width direction Y of the piezoelectric element 50.

[0065] The conductive layer 44c is laminated to the base insulating layer 44b, a portion of which is formed overlapping the recess HE2 of the base insulating layer 44b and is recessed along the recess HE2, forming a recess one level lower. A recess (third recess) HE3 is further formed in the conductive layer 44c. The recess HE3 is formed by reducing the layer thickness to about 1 / 2 or so by half-etching a portion of the conductive layer 44c. The recess HE3 is formed, for example, in a substantially rectangular shape on one end side in the width direction Y of the second connection pad 70b.

[0066] The cover insulating layer 44d is laminated to the conductive layer 44c and the base insulating layer 44b. A portion of the cover insulating layer 44d is formed overlapping the recess HE3 and is recessed along the recess HE3, forming a recess one level lower.

[0067] Thus, the mounting portion 60 has recesses HE1, HE2, which are two levels lower, in regions opposite the end portions in the width direction of the piezoelectric element 50 on both sides in the width direction of the second connection pad 70b. In this embodiment, the recess HE3, which is one level further lower, is on one end side in the width direction of the second connection pad 70b. As described above, the mounting portion 60 has recesses HE1, HE2, which are two levels lower and are substantially rectangular in shape, on both sides in the width direction of the first connection pad 70a in regions opposite the end portions in the width direction of the piezoelectric element 50, and has the recess HE3, which is one level further lower, on one end side in the width direction.

[0068] As Figure 7As shown, in the region where the recesses HE1, HE2, and HE3 are provided, the distance between the lower surface of the end portion of the piezoelectric element 50 in the width direction Y and the cover insulating layer 44d is increased. A portion of the conductive adhesive Ad filled between the lower surface of the piezoelectric element 50 and the second connection pad 70b flows into the region where the distance is increased. As a result, the conductive adhesive Ad that overflows outward from the piezoelectric element 50 is less likely to accumulate on the side surfaces SL1 and SL2 of the piezoelectric element 50. As a result, a sufficient spacing margin MG can be ensured between the conductive adhesive Ad and the intermediate electrode layer (third electrode portion 54c) of the piezoelectric element 50, thereby reducing the risk of a short circuit between the conductive adhesive and the third electrode portion 54c, that is, the risk of a short circuit between the second electrode 56 (fifth electrode portion 56a) and the first electrode 54 ((third electrode portion 54c)) in contact with the conductive adhesive.

[0069] Although not shown in the figure, in the mounting portion 60 on the first connecting pad 70a side, as in the second connecting pad 70b side, the spacing margin MG between the conductive adhesive Ad and the electrode portion of the piezoelectric element 50 can be fully ensured, thereby reducing the risk of short circuit between the first electrode 54 and the second electrode 56.

[0070] Furthermore, the number of recesses HE1 and HE2 in the metal plate 44a and the base insulating layer 44b relative to the connection pad is not limited to two, and one or more recesses HE1 and HE2 may be provided relative to one connection pad. The shape of the recesses HE1, HE2, and HE3 is not limited to a rectangle, and various other shapes may be selected.

[0071] In the HDD configured as described above, by applying a voltage (driving signal) to the piezoelectric element 50 via the driving wiring 45b, the piezoelectric element 50 expands and contracts along its longitudinal direction X (a direction parallel to the central axis C of the suspension). Figure 3 As shown by the arrow D, by driving the two piezoelectric elements 50 in opposite directions of expansion and contraction, the pair of first bridge portions 47c also produce strokes in opposite directions. The first bridge portion 47c causes the tongue portion 36a of the universal joint portion 36 and the magnetic head 17 to swing around the recess 48 in the direction of arrow D via the handle 36f. In this way, the expansion and contraction action of the piezoelectric element 50 can cause a slight displacement of the magnetic head 17. In addition, the swing direction D of the magnetic head 17 corresponds to the seek direction (cross-track direction) of the magnetic head 17 on the magnetic disk 18.

[0072] According to the present embodiment, in the mounting portion 60 of the flexure 40 in which the piezoelectric element 50 is mounted, recesses HE1, HE2 are formed in regions opposite the ends in the width direction of the piezoelectric element 50, and a portion of the cover insulating layer 44d is provided as a recess that is recessed along the recesses. In the recesses, the distance from the lower surface of the piezoelectric element 50 to the cover insulating layer 44d widens, and the spacing margin MG between the electrically conductive adhesive Ad and the electrode portion of the piezoelectric element 50 can be sufficiently ensured. Thus, the risk of short-circuiting between the first electrode 54 and the second electrode 56 can be reduced.

[0073] With the above, according to the present embodiment, a head suspension assembly and a disc device in which the reliability of electrical connection of the electrode of the piezoelectric material and the electrically conductive adhesive is improved while short-circuiting is suppressed can be provided.

[0074] Next, the head suspension assembly of the HDD of another embodiment will be described. In the following description of the other embodiment, the same reference numerals are assigned to portions common to the first embodiment described above, and detailed description thereof will be omitted or simplified.

[0075] (Second Embodiment)

[0076] Figure 8 is a cross-sectional view of a piezoelectric element and a mounting portion in the head suspension assembly of the second embodiment.

[0077] As shown in the drawing, according to the second embodiment, the mounting portion 60 of the flexure 40 has two opening portions OP1 formed in the cover insulating layer 44d. The opening portions OP1 are formed in regions of the cover insulating layer 44d in which the recess HE2 and the recess HE3 are disposed so as to overlap each other. The opening portions OP1 are formed, for example, in a rectangular shape, at positions in the recess HE2 opposite the ends in the width direction Y of the piezoelectric element 50 or at positions outside the ends.

[0078] The electrically conductive adhesive Ad that fills between the connection pad 70b and the piezoelectric element 50 is located on the cover insulating layer 44d, and a portion thereof also flows into the opening portions OP1.

[0079] In the second embodiment, the other structures of the head suspension assembly and the HDD are the same as those of the head suspension assembly and the HDD of the first embodiment.

[0080] According to the above-described structure of the second embodiment, a portion of the conductive adhesive Ad filled between the lower surface of the piezoelectric element 50 and the second connection pad 70b flows into the recesses and the opening portion OP1 of the cover insulating layer 44d formed by the recesses HE1, HE1, HE3. Thus, the conductive adhesive Ad overflowing from the piezoelectric element 50 to the outside is less likely to pile up to the side surfaces SL1, SL2 of the piezoelectric element 50. As a result, the margin MG between the conductive adhesive Ad and the intermediate electrode layer (the third electrode portion 54c) of the piezoelectric element 50 can be sufficiently ensured, and the risk of short-circuiting of the first electrode 54 and the second electrode 56 can be further reduced.

[0081] With the above, according to the second embodiment, it is possible to provide a head suspension assembly and a disc device in which the reliability of electrical connection of the electrode of the piezoelectric material and the conductive adhesive is improved while suppressing short-circuiting.

[0082] (Third Embodiment)

[0083] Figure 9 FIG. 8 is a cross-sectional view of a piezoelectric element and a mounting portion in a head suspension assembly of the third embodiment.

[0084] As shown in the figure, according to the third embodiment, the mounting portion 60 of the flexure 40 further has the two opening portions OP1 shown in the second embodiment and a second cover insulating layer 44e laminated to the cover insulating layer 44d.

[0085] The second cover insulating layer 44e has, for example, a rectangular shape and is laminated to the cover insulating layer 44d. The two cover insulating layers 44e are located on both sides in the width direction Y of the second connection pad 70b and are arranged in alignment with the side edges of the opening 72b.

[0086] Further, in the present embodiment, the conductive layer 44c is configured to omit the portion corresponding to the recess EH3. In the third embodiment, the other structures of the head suspension assembly and the HDD are the same as those of the head suspension assembly and the HDD of the first embodiment.

[0087] By additionally providing the second cover insulating layer 44e as described above, the distance between the lower surface of the piezoelectric element 50 and the cover insulating layer 44d located on the outside in the width direction of the piezoelectric element 50 is further widened. Thus, when the piezoelectric element 50 is mounted, the conductive adhesive Ad overflowing from the piezoelectric element 50 is less likely to pile up to the side surfaces SL1, SL2 of the piezoelectric element 50. As a result, the margin MG between the conductive adhesive Ad and the electrode portion of the piezoelectric element 50 can be further increased, and the risk of short-circuiting of the conductive adhesive and the electrode portion can be reduced.

[0088] Therefore, in the third embodiment, the same effects as the first and second embodiments can be obtained, that is, a head suspension assembly and a disc device in which reliability of electrical connection is improved while short-circuit is suppressed can be provided.

[0089] (4th Embodiment)

[0090] Figure 10 FIG. 6 is a cross-sectional view of a piezoelectric element and a mounting portion in a head suspension assembly according to the 4th embodiment.

[0091] As shown in the figure, according to the 4th embodiment, in the mounting portion 60 of the flexure 40, the metal plate 44a does not have an etching region (recess HE1) and is formed to a certain plate thickness.

[0092] The base insulating layer 44b laminated on the metal plate 44a has an etching region (recess HE2) in which the layer thickness is reduced by one level. The recess HE2 is formed by performing half-etching on a portion of the base insulating layer 44b to reduce the layer thickness to approximately 1 / 2. The recess HE2 is formed, for example, in a substantially rectangular shape and is located on both sides in the width direction Y of the second connection pad 70b. Further, the two recesses HE2 are located opposite to both end portions in the width direction Y of the piezoelectric element 50.

[0093] The conductive layer 44c is laminated on the base insulating layer 44b and partially overlaps the recess HE2 of the base insulating layer 44b. The cover insulating layer 44d is laminated on the conductive layer 44c and the base insulating layer 44b. A portion of the cover insulating layer 44d is formed to overlap the recess HE2 and is recessed along the recess HE2 to form a recess in which the layer thickness is reduced by one level. Further, the cover insulating layer 44d has two opening portions OP1. The opening portions OP1 are formed in regions of the cover insulating layer 44d in which the recess HE2 is disposed. The opening portions OP1 are formed, for example, in a rectangular shape and are disposed in the recess HE2 opposite to the end portions in the width direction Y of the piezoelectric element 50 or outside the width direction of the end portions.

[0094] The conductive adhesive Ad filled between the connection pad 70b and the piezoelectric element 50 is located on the cover insulating layer 44d and partially flows into the recess and the opening portion OP1 of the cover insulating layer.

[0095] In the 4th embodiment, the other structures of the head suspension assembly and the HDD are the same as those of the head suspension assembly and the HDD according to the first embodiment.

[0096] According to the fourth embodiment constructed as described above, even when the recess in the metal plate 44a is omitted, by providing the recess HE2 in the base insulating layer 44b and the opening OP1 in the cover insulating layer 44d, the distance between the lower surface of the piezoelectric element 50 and the cover insulating layer 44d located on the outside in the width direction of the piezoelectric element 50 can be increased. Therefore, when the piezoelectric element 50 is mounted, the conductive adhesive Ad that overflows from the piezoelectric element 50 is less likely to accumulate on the side surfaces SL1 and SL2 of the piezoelectric element 50. As a result, the spacing margin MG between the conductive adhesive Ad and the electrode portion of the piezoelectric element 50 can be increased, and the risk of short circuits between the conductive adhesive and the electrode portion can be reduced. Therefore, in the fourth embodiment, a head gimbal assembly and disk device can be provided that suppress short circuits and improve the reliability of electrical connections.

[0097] The present invention is not limited to the above-described embodiments as such. During implementation, the constituent elements may be modified and concretized within the scope of the present invention. In addition, various inventions may be formed by appropriately combining the multiple constituent elements disclosed in the above-described embodiments. For example, some constituent elements may be deleted from all the constituent elements shown in the embodiments. Furthermore, constituent elements across different embodiments may be appropriately combined.

[0098] For example, in the above-described embodiment, the mounting portion of the flexure is configured to include etched regions (recesses HE1 and HE2) on both the first and second connection pad sides. However, the present invention is not limited thereto and may include an etched region only on one of the connection pad sides. For example, in the piezoelectric element shown in this embodiment, the portion of the piezoelectric element adjacent to the first and second electrodes in the thickness direction of the piezoelectric element is only the end portion on the second connection pad side. Therefore, by providing the etched region (HE1, HE2, opening P1) only on the second connection pad side, the risk of a short circuit between the first and second electrodes can be reduced.

[0099] In the above embodiment, a pair of piezoelectric elements 50 is provided as a structure mounted on the universal joint portion 36 and located on the base end side of the load beam 35 relative to the magnetic head 17, but is not limited to this. A pair of piezoelectric elements can also be arranged on both sides of the width direction of the support portion (tongue portion) supporting the magnetic head, and arranged side by side with the magnetic head. The piezoelectric element is not limited to a pair, for example, a single piezoelectric element can also be used. The connection pad is not limited to a rectangular shape, and various shapes such as an elliptical, circular, and polygonal shape can be selected.

[0100] Furthermore, although the piezoelectric element is shown as having a first piezoelectric substrate, a second piezoelectric substrate, and a restraining layer, this is not limiting. For example, a piezoelectric element having a single piezoelectric substrate and a restraining layer may also be used. In this case, the second electrode has a structure in which the intermediate electrode layer (the seventh electrode portion) is omitted.

Claims

1. A head suspension assembly comprising: Support plate; a wiring member including a mounting portion having a first connection pad and a second connection pad, and provided on the support plate; A head mounted on the wiring member; and a piezoelectric element having a first electrode connected to the first connection pad via a conductive adhesive and a second electrode connected to the second connection pad via a conductive adhesive, mounted on the mounting portion; The wiring member includes: a metal plate arranged on the support plate; a base insulating layer stacked on the metal plate; a conductive layer stacked on the base insulating layer and having the first connection pad, the second connection pad, and a plurality of wirings formed thereon; and a cover insulating layer stacked on the conductive layer and the base insulating layer. The cover insulating layer has a first pad opening, and the first electrode passes through the first pad opening and is connected to the conductive layer via the conductive adhesive material. The basic insulating layer includes a first region located below the first pad opening and a second region located below a side surface of the piezoelectric element, and a thickness of the basic insulating layer in the second region is smaller than a thickness of the basic insulating layer in the first region.

2. The head suspension assembly according to claim 1, The mounting portion includes a second cover insulating layer stacked on the cover insulating layer in the vicinity of the first connection pad or the second connection pad.

3. The head suspension assembly according to claim 1 or 2, The metal plate includes a third region located below the first pad opening and a fourth region located below the side surface of the piezoelectric element. The thickness of the metal plate in the fourth region is smaller than the thickness of the metal plate in the third region.

4. The head suspension assembly according to claim 1, The conductive layer includes a fifth region located below the first pad opening and a sixth region located below the side surface of the piezoelectric element. The thickness of the conductive layer in the sixth region is smaller than the thickness of the conductive layer in the fifth region.

5. The head suspension assembly according to claim 1 or 2, The piezoelectric element further comprises: A piezoelectric substrate is formed of a piezoelectric material and has a first main surface, a second main surface opposite to the first main surface, and a first side surface and a second side surface opposite to each other. The first electrode includes a first electrode portion provided on the first main surface at an end portion on the first side surface side, a second electrode portion provided on the first side surface, and a third electrode portion provided on the second main surface. The second electrode includes a fifth electrode portion provided on the first main surface and facing the third electrode portion across the piezoelectric substrate, and a sixth electrode portion provided on the second side surface. The first electrode portion is connected to the first connection pad via the conductive adhesive material, and the fifth electrode portion is connected to the second connection pad via the conductive adhesive material.

6. A disk device comprising: a freely rotating magnetic disk; and The head suspension assembly according to claim 1 or 2.

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