Disk device

Abstract

To provide a disk device capable of preventing a bonded body from causing a short circuit between the two electrodes of a piezoelectric element.SOLUTION: A disk device according to an embodiment includes a magnetic disk, a magnetic head, a piezoelectric element, a flexure, a first bonded body, and a second bonded body. The piezoelectric element has a first piezoelectric body, a first electrode and a second electrode provided on a first surface of the first piezoelectric body, and a third electrode provided on a second surface of the first piezoelectric body and connected to the second electrode. The flexure has an outer surface and a first pad and a second pad provided on the outer surface, in which a first through hole that opens to the first pad is provided at a position where the first electrode and the third electrode overlap. The first bonded body bonds the first pad and the first electrode and is partially accommodated in the first through hole. The second bonded body bonds the second pad and the second electrode.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a disk device. [Background technology]

[0002] A disk device such as a hard disk drive has a magnetic disk and a magnetic head that reads and writes information from and to the magnetic disk. The magnetic head is mounted on a flexible flexure. Furthermore, a piezoelectric element that adjusts the position of the magnetic head by deforming the flexure is attached to the flexure with a bonding material such as a conductive adhesive. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] U.S. Pat. No. 1,098,4825 Summary of the Invention [Problem to be solved by the invention]

[0004] In a piezoelectric element, a piezoelectric body is placed between two electrodes. When one electrode of the piezoelectric element is mounted on the pad of the flexure, the bonded body is crushed between the piezoelectric element and the flexure. There is a risk that the crushed bonded body will spread along the side of the piezoelectric element to the other electrode.

[0005] One example of a problem to be solved by the present invention is to provide a disk drive capable of preventing a joint from shorting two electrodes of a piezoelectric element. [Means for solving the problem]

[0006] A disk device according to one embodiment includes a magnetic disk, a magnetic head, a piezoelectric element, a flexure, a conductive first joint, and a conductive second joint. The magnetic head is configured to read and write information from and to the magnetic disk. The piezoelectric element includes a first piezoelectric body, a first electrode provided on a first surface of the first piezoelectric body, a second electrode provided on the first surface at a position spaced apart from the first electrode in a first direction along the first surface, and a third electrode provided on a second surface of the first piezoelectric body located opposite to the first surface and connected to the second electrode. The flexure has an outer surface facing the first electrode and the second electrode, a first pad provided on the outer surface, and a second pad provided on the outer surface at a position spaced from the first pad in the first direction, and a first through hole is provided in the first pad at a position where the first electrode and the third electrode overlap in the second direction in which the first surface faces, and the magnetic head is mounted on the flexure. The first bonding body bonds the first pad and the first electrode and is partially housed in the first through hole. The second bonding body bonds the second pad and the second electrode. [Brief description of the drawings]

[0007] [Figure 1] FIG. 1 is an exemplary exploded perspective view of a HDD according to the first embodiment. [Diagram 2] FIG. 2 is an exemplary perspective view partially illustrating the HGA of the first embodiment. [Diagram 3] FIG. 3 is an exemplary plan view showing a portion of the HGA of the first embodiment. [Figure 4] FIG. 4 is an exemplary cross-sectional view showing a part of the HGA of the first embodiment taken along line F4-F4 in FIG. [Diagram 5] FIG. 5 is an exemplary cross-sectional view showing a part of the HGA of the first embodiment taken along line F5-F5 in FIG. [Figure 6] FIG. 6 is an exemplary cross-sectional view showing a portion of an HGA according to the second embodiment. [Figure 7]FIG. 7 is an exemplary plan view showing a portion of an HGA according to the third embodiment. [Figure 8] FIG. 8 is an exemplary cross-sectional view showing a part of the HGA according to the third embodiment taken along line F8-F8 in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] (First embodiment) The first embodiment will be described below with reference to FIGS. 1 to 5. In this specification, components according to the embodiment and their descriptions may be described in a number of ways. The components and their descriptions are merely examples and are not limited by the expressions in this specification. The components may be identified by names different from those in this specification. The components may also be described by expressions different from those in this specification.

[0009] In the following description, "inhibit" is defined as, for example, preventing the occurrence of an event, action, or effect, or reducing the magnitude of an event, action, or effect.

[0010] 1 is an exemplary exploded perspective view showing a hard disk drive (HDD) 10 according to the first embodiment. The HDD 10 is an example of a disk device, and may also be called an electronic device, a storage device, an external storage device, or a magnetic disk device.

[0011] The HDD 10 includes a housing 11, a plurality of magnetic disks 12, a spindle motor 13, a head stack assembly (HSA) 14, a voice coil motor (VCM) 15, a ramp load mechanism 16, and a printed circuit board (PCB) 17. The magnetic disks 12 may also be called disks or platters.

[0012] 1, for the sake of convenience, a Z axis and a Z direction are defined in this specification. The Z axis is provided along the thickness of the HDD 10. The Z direction is a direction along the Z axis, and includes a +Z direction indicated by the Z axis arrow and a -Z direction opposite to the Z axis arrow.

[0013] The housing 11 has a base 21, an inner cover 22, and an outer cover 23. The housing 11 is not limited to this example. The base 21, the inner cover 22, and the outer cover 23 are each made of a metal material such as an aluminum alloy. The materials of the base 21, the inner cover 22, and the outer cover 23 may be different from each other.

[0014] The base 21 is formed in a substantially rectangular box shape that is open in the +Z direction. The base 21 houses a plurality of magnetic disks 12, a spindle motor 13, an HSA 14, a VCM 15, and a ramp load mechanism 16.

[0015] The base 21 has a bottom wall 25 and side walls 26. The bottom wall 25 is formed in a substantially rectangular (quadrilateral) plate shape arranged substantially perpendicular to the Z direction. The side walls 26 protrude from the edge of the bottom wall 25 in substantially the +Z direction and are formed in a substantially rectangular frame shape.

[0016] The inner cover 22 is attached to the end of the side wall 26 in the +Z direction by, for example, screws, and closes the base 21. The outer cover 23 covers the inner cover 22, and is attached to the end of the side wall 26 in the +Z direction by, for example, welding.

[0017] An air vent 27 is provided in the inner cover 22. Furthermore, an air vent 28 is provided in the outer cover 23. After components are attached inside the base 21 and the inner cover 22 and the outer cover 23 are attached to the base 21, air inside the housing 11 is evacuated through the air vents 27, 28. Furthermore, the inside of the housing 11 is filled with a gas other than air.

[0018] The gas filled inside the housing 11 is, for example, a low-density gas having a density lower than air, an inert gas having a low reactivity, or the like. For example, helium is filled inside the housing 11. Note that other fluids may be filled inside the housing 11. Furthermore, the inside of the housing 11 may be kept at a vacuum, a low pressure close to a vacuum, or a negative pressure lower than atmospheric pressure.

[0019] The vent hole 28 of the outer cover 23 is closed by a seal 29. The seal 29 air-tightly seals the vent hole 28 and restricts the fluid filled inside the housing 11 from leaking from the vent hole 28 to the outside of the housing 11.

[0020] The magnetic disks 12 are formed in a disk shape and arranged so as to be substantially perpendicular to the Z direction. The magnetic disks 12 are arranged in the Z direction with gaps between them. A magnetic recording layer is provided on the surface of each of the magnetic disks 12.

[0021] The spindle motor 13 supports and integrally rotates the multiple magnetic disks 12. The multiple magnetic disks 12 are held on a hub of the spindle motor 13 by, for example, a clamp spring.

[0022] A support shaft 31 is provided in the housing 11 and is spaced apart from the magnetic disk 12. The support shaft 31 extends, for example, from the bottom wall 25 of the housing 11 in approximately the +Z direction. The HSA 14 is supported by the support shaft 31 so as to be rotatable.

[0023] The HSA 14 has a carriage 35, a plurality of head gimbal assemblies (HGA) 36, and a flexible printed circuit board (FPC) 37. The carriage 35 has an actuator block 41 and a plurality of arms 42.

[0024] The actuator block 41 and the arms 42 are integrally formed from, for example, an aluminum alloy. However, the materials of the actuator block 41 and the arms 42 are not limited to this example.

[0025] The actuator block 41 is supported on the support shaft 31 via a bearing so as to be rotatable around the support shaft 31. This allows the carriage 35 to rotate around the support shaft 31.

[0026] The arms 42 protrude generally parallel to each other in a direction generally perpendicular to the Z direction from the actuator block 41. Note that the HSA 14 may be divided so that the arms 42 protrude from each of the actuator blocks 41.

[0027] The multiple arms 42 are aligned in the Z direction with gaps between them. When the carriage 35 including the arms 42 rotates in one direction around the support shaft 31, each of the multiple arms 42 can enter a gap between two adjacent magnetic disks 12 among the multiple magnetic disks 12. When the carriage 35 rotates in the other direction, each of the multiple arms 42 can exit from the gap between the two adjacent magnetic disks 12.

[0028] FIG. 2 is an exemplary perspective view partially showing the HGA 36 of the first embodiment. As shown in FIG. 2, for convenience, an X-axis and a Y-axis are further defined in this specification. The X-axis, the Y-axis, and the Z-axis are mutually orthogonal. The Y-axis is provided along the arm 42. Furthermore, an X-direction and a Y-direction are further defined in this specification. The X-direction is a direction along the X-axis, and includes a +X-direction indicated by an arrow of the X-axis, and a -X-direction that is the opposite direction of the arrow of the X-axis. The Y-direction is a direction along the Y-axis, and includes a +Y-direction indicated by an arrow of the Y-axis, and a -Y-direction that is the opposite direction of the arrow of the Y-axis.

[0029] The multiple arms 42 protrude in the +Y direction from the actuator block 41. Therefore, the Y direction is the longitudinal direction of the arms 42. The X direction is the lateral direction of the arms 42. The X and Y directions change as the carriage 35 rotates.

[0030] Each of the multiple HGAs 36 is attached to the tip of the arm 42 so as to protrude from the arm 42 in approximately the +Y direction. This allows the multiple HGAs 36 to be lined up in the Z direction with gaps between them. Each of the multiple HGAs 36 has a magnetic head 51 and a suspension 52. The magnetic head 51 may also be referred to as a slider.

[0031] The magnetic head 51 records and reproduces information on a corresponding one of the multiple magnetic disks 12. In other words, the magnetic head 51 reads and writes information from and to the magnetic disk 12.

[0032] The suspension 52 is attached to the arm 42 and holds the magnetic head 51. The suspension 52 has a base plate 55, a load beam 56, and a flexure 57.

[0033] The base plate 55 and the load beam 56 are made of, for example, stainless steel (SUS). However, the materials of the base plate 55 and the load beam 56 are not limited to this example. The base plate 55 and the load beam 56 may be made of different materials.

[0034] The base plate 55 is formed in a substantially rectangular plate shape disposed so as to be substantially perpendicular to the Z direction. The base plate 55 is attached to the tip portion of the arm 42 by, for example, crimping.

[0035] The load beam 56 is formed in a plate shape that is thinner than the base plate 55. The load beam 56 is fixed to the base plate 55 by, for example, spot welding. The load beam 56 extends from the base plate 55 approximately in the +Y direction.

[0036] The flexure 57 is a type of flexible printed wiring board formed in a long and narrow strip shape. The flexure 57 has, for example, a gimbal portion 61 and a suspension tail 62.

[0037] The gimbal portion 61 is provided at an end of the flexure 57 in the +Y direction. The magnetic head 51 is mounted on the gimbal portion 61. The gimbal portion 61 is attached to the load beam 56 so that the portion of the gimbal portion on which the magnetic head 51 is mounted is rotatable.

[0038] The suspension tail 62 extends from the gimbal portion 61 toward the actuator block 41. Note that other portions may be provided between the gimbal portion 61 and the suspension tail 62.

[0039] An end of the suspension tail 62 in the -Y direction is connected to one end of the FPC 37 attached to the actuator block 41 in Fig. 1. The other end of the FPC 37 is connected to a connector provided on the bottom wall 25, for example.

[0040] The carriage 35 rotates about the support shaft 31 to move the magnetic head 51 relative to the corresponding magnetic disk 12. The VCM 15 rotates the carriage 35 about the support shaft 31 to move the magnetic head 51 along the magnetic disk 12 to a desired position.

[0041] The VCM 15 has a voice coil, a pair of yokes, and a magnet attached to the yoke. The voice coil is held by an actuator block 41. When the magnetic head 51 moves to the outer edge of the magnetic disk 12 by the rotation of the carriage 35 by the VCM 15, the ramp load mechanism 16 holds the magnetic head 51 at a position separated from the magnetic disk 12.

[0042] The PCB 17 is, for example, a rigid board such as a glass epoxy board, and is a multi-layer board or a build-up board, etc. The PCB 17 is disposed outside the housing 11 and attached to the bottom wall 25.

[0043] Various electronic components are mounted on the PCB 17, such as a relay connector electrically connected to the FPC 37, an interface (I / F) connector connected to a host computer, and a controller that controls the operation of the HDD 10. The relay connector is electrically connected to the FPC 37 via a connector provided on the bottom wall 25. The controller of the PCB 17 drives the VCM 15 to control the position of the magnetic head 51.

[0044] 2, the HGA 36 of this embodiment has a pair of first microactuators (MA) 65 and a pair of second microactuators (MA) 66. The second MAs 66 are an example of piezoelectric elements.

[0045] The first MA 65 and the second MA 66 are piezoelectric elements. The first MA 65 and the second MA 66 are, for example, bulk type piezoelectric elements. The first MA 65 and the second MA 66 may be bulk laminated type or thin film type piezoelectric elements.

[0046] The pair of first MAs 65 are attached, for example, to a portion where the base plate 55 and the load beam 56 are connected. Note that the first MAs 65 are not limited to this example. The pair of first MAs 65 are disposed spaced apart from each other in the X direction.

[0047] The first MA 65 can expand and contract in the Y direction according to the applied voltage. When the pair of first MAs 65 expand and contract individually, for example, the load beam 56 elastically bends in the X direction. As a result, the first MA 65 adjusts the position of the magnetic head 51.

[0048] The pair of second MAs 66 are mounted, for example, on the outer surface 61a of the gimbal portion 61. In this embodiment, the outer surface 61a is a surface facing the corresponding magnetic disk 12. The magnetic head 51 is also mounted on the outer surface 61a. However, the outer surface 61a is not limited to this example.

[0049] The pair of second MAs 66 are spaced apart from each other in the X direction. The second MAs 66 can expand and contract in the Y direction depending on the voltage applied thereto. The pair of second MAs 66 expand and contract individually, causing the gimbal portion 61 to bend elastically in the X direction. As a result, the second MAs 66 adjust the position of the magnetic head 51.

[0050] As described above, the HDD 10 of this embodiment moves the magnetic head 51 using the VCM 15, the first MA 65, and the second MA 66. That is, the HDD 10 adjusts the position of the magnetic head 51 by a so-called Triple Stage Actuator (TSA) method.

[0051] The gimbal portion 61 has two MA attachment portions 71. Each of the two second MAs 66 is mounted on the flexure 57 at a corresponding one of the two MA attachment portions 71. The MA attachment portion 71 may be provided at another position on the flexure 57.

[0052] Fig. 3 is an exemplary plan view showing a part of the HGA 36 of the first embodiment. As shown in Fig. 3, each of the two MA mounting parts 71 has a peripheral part 75, a first protruding part 76, and a second protruding part 77. The peripheral part 75 is an example of a base part.

[0053] The peripheral portion 75 extends around the first protrusion 76 and the second protrusion 77 so as to surround the first protrusion 76 and the second protrusion 77. The first protrusion 76 protrudes from the peripheral portion 75 in approximately the -Y direction. The -Y direction is an example of the first direction. The second protrusion 77 protrudes from the peripheral portion 75 in approximately the +Y direction at a position spaced apart from the first protrusion 76 in the -Y direction. The first protrusion 76 and the second protrusion 77 are spaced apart from each other.

[0054] A first pad 81 is provided on the outer surface 61a of the first protrusion 76. A second pad 82 is provided on the outer surface 61a of the second protrusion 77. That is, the second pad 82 is spaced apart from the first pad 81 in the -Y direction.

[0055] An end portion in the +Y direction of the corresponding second MA 66 is joined to a first pad 81 by a first adhesive 85. The first adhesive 85 is an example of a first bonding body. An end portion in the -Y direction of the corresponding second MA 66 is joined to a second pad 82 by a second adhesive 86. The second adhesive 86 is an example of a second bonding body.

[0056] In this embodiment, the first adhesive 85 and the second adhesive 86 are conductive adhesives. For example, the first adhesive 85 and the second adhesive 86 are epoxy adhesives mixed with a conductive filler such as silver. The viscosity of the first adhesive 85 and the second adhesive 86 is, for example, 8600 to 14600 cP. Note that the first bonding body and the second bonding body are not limited to this example, and may be other conductive bonding bodies such as solder.

[0057] The second MA 66 expands and contracts in the Y direction, thereby changing the distance between the first protrusion 76 and the second protrusion 77. For example, the distance between the first protrusion 76 and the second protrusion 77 in one MA mounting part 71 decreases, and the distance between the first protrusion 76 and the second protrusion 77 in the other MA mounting part 71 increases, causing the gimbal part 61 to bend elastically.

[0058] Fig. 4 is an exemplary cross-sectional view showing a part of the HGA 36 of the first embodiment along the line F4-F4 in Fig. 3. Fig. 5 is an exemplary cross-sectional view showing a part of the HGA 36 of the first embodiment along the line F5-F5 in Fig. 3.

[0059] 4, the second MA 66 has a first piezoelectric body 91, a second piezoelectric body 92, a ground terminal 93, and a signal terminal 94. The number of piezoelectric bodies included in the second MA 66 is not limited to two.

[0060] Each of the first piezoelectric body 91 and the second piezoelectric body 92 is formed in a substantially rectangular parallelepiped shape extending in the Y direction. The first piezoelectric body 91 and the second piezoelectric body 92 are formed in substantially the same shape and are stacked in the Z direction.

[0061] The first piezoelectric body 91 has a bottom surface 91a, a top surface 91b, and two end surfaces 91c and 91d. The bottom surface 91a is an example of a first surface. The top surface 91b is an example of a second surface. The bottom surface 91a, the top surface 91b, and the end surfaces 91c and 91d are each formed to be substantially flat. The bottom surface 91a faces substantially in the -Z direction. The top surface 91b is located opposite the bottom surface 91a and faces substantially in the +Z direction. The end surface 91c faces substantially in the +Y direction. The end surface 91d is located opposite the end surface 91c and faces substantially in the -Y direction.

[0062] The lower surface 91a faces the outer surface 61a of the gimbal portion 61. In this embodiment, the lower surface 91a faces the first pad 81 of the first protruding portion 76 and the second pad 82 of the second protruding portion 77.

[0063] The second piezoelectric body 92 has a bottom surface 92a, a top surface 92b, and two end surfaces 92c and 92d. The bottom surface 92a is an example of a third surface. The top surface 92b is an example of a fourth surface. The bottom surface 92a, the top surface 92b, and the end surfaces 92c and 92d are each formed to be substantially flat. The bottom surface 92a faces substantially in the -Z direction. The bottom surface 92a is attached to the top surface 91b of the first piezoelectric body 91. The top surface 92b is located on the opposite side of the bottom surface 92a and faces substantially in the +Z direction. The end surface 92c faces substantially in the +Y direction. The end surface 92d is located on the opposite side of the end surface 92c and faces substantially in the -Y direction.

[0064] The ground terminal 93 and the signal terminal 94 are made of a conductive material such as copper. The ground terminal 93 and the signal terminal 94 are attached to the first piezoelectric body 91 and the second piezoelectric body 92, and are spaced apart from each other.

[0065] The ground terminal 93 has a lower film 101, an upper film 102, and a side film 103. Note that the ground terminal 93 is not limited to this example. The lower film 101 is an example of a first electrode. The upper film 102 is an example of a fourth electrode.

[0066] The lower film 101 is provided on the lower surface 91a of the first piezoelectric body 91. The lower film 101 is spaced in the +Y direction from an end of the lower surface 91a in the -Y direction. The upper film 102 is provided on the upper surface 92b of the second piezoelectric body 92. The upper film 102 is spaced in the +Y direction from an end of the upper surface 92b in the -Y direction. In the Y direction, the upper film 102 is longer than the lower film 101.

[0067] The lateral film 103 is provided on an end surface 91c of the first piezoelectric body 91 and an end surface 92c of the second piezoelectric body 92. The lateral film 103 connects the lower film 101 and the upper film 102 to each other. Therefore, the lower film 101, the upper film 102, and the lateral film 103 can be at the same potential.

[0068] The signal terminal 94 has a lower membrane 105, a middle membrane 106, and a lateral membrane 107. Note that the signal terminal 94 is not limited to this example. The lower membrane 105 is an example of a second electrode. The middle membrane 106 is an example of a third electrode.

[0069] The lower film 105 is provided on the lower surface 91a of the first piezoelectric body 91. The lower film 105 is spaced apart from the lower film 101 of the ground terminal 93 in the -Y direction. The middle film 106 is provided on the upper surface 91b of the first piezoelectric body 91. Therefore, the middle film 106 is located between the first piezoelectric body 91 and the second piezoelectric body 92. The middle film 106 may be provided on the lower surface 92a of the second piezoelectric body 92. In this case, the middle film 106 is also substantially provided on the upper surface 91b of the first piezoelectric body 91. In the Y direction, the middle film 106 is longer than the lower film 105.

[0070] The lateral film 107 is provided on an end surface 91d of the first piezoelectric body 91 and an end surface 92d of the second piezoelectric body 92. The lateral film 107 connects the lower film 105 and the middle film 106 to each other. Therefore, the lower film 105, the middle film 106, and the lateral film 107 can be at the same potential.

[0071] The upper film 102 of the ground terminal 93 overlaps the middle film 106 of the signal terminal 94 in the -Z direction. Therefore, the second piezoelectric body 92 is interposed between the upper film 102 and the middle film 106. The -Z direction is the direction in which the lower surface 91a faces and is an example of the second direction. The middle film 106 of the signal terminal 94 overlaps the lower film 101 of the ground terminal 93 in the -Z direction. Therefore, the first piezoelectric body 91 is interposed between the middle film 106 and the lower film 101.

[0072] As shown in FIG. 5, the second MA 66 has two side surfaces 66a, 66b. The side surface 66a is an example of an end surface. The side surface 66a is provided at an end surface of the second MA 66 in the +X direction. The +X direction is a direction along the lower surface 91a and perpendicular to the -Y direction, and is an example of a third direction. The side surface 66a is formed substantially flat and faces substantially in the +X direction. The side surface 66b is located on the opposite side of the side surface 66a. The side surface 66b is provided at an end surface of the second MA 66 in the -X direction. The side surface 66b is formed substantially flat and faces substantially in the -X direction.

[0073] The ground terminal 93 and the signal terminal 94 are provided from one side surface 66a to the other side surface 66b of the second MA 66. Therefore, the lower film 101, the upper film 102, and the side film 103 of the ground terminal 93 and the lower film 105, the middle film 106, and the side film 107 of the signal terminal 94 are exposed to the outside of the second MA 66 at the sides 66a, 66b. The parts of the ground terminal 93 and the signal terminal 94 exposed at the sides 66a, 66b may be covered by elements such as the first adhesive 85 and the second adhesive 86 that are not included in the second MA 66.

[0074] 4, the outer surface 61a of the first protrusion 76 faces the lower film 101 of the ground terminal 93. In this embodiment, the first protrusion 76 is spaced apart from the signal terminal 94. The first adhesive 85 bonds the first pad 81 provided on the first protrusion 76 to the lower film 101 and the side film 103 of the ground terminal 93. In other words, the first adhesive 85 physically and electrically connects the first pad 81 and the ground terminal 93.

[0075] The outer surface 61a of the second protrusion 77 faces the lower film 105 of the signal terminal 94. In this embodiment, the second protrusion 77 is spaced apart from the ground terminal 93. The second adhesive 86 bonds the second pad 82 provided on the second protrusion 77 to the lower film 105 and the side film 107 of the signal terminal 94. In other words, the second adhesive 86 physically and electrically connects the second pad 82 and the signal terminal 94.

[0076] 5, the first adhesive 85 and the second adhesive 86 may be further attached to the side surfaces 66a, 66b of the second MA 66. The first adhesive 85 is spaced apart from the second pad 82, the second adhesive 86, and the signal terminal 94. The second adhesive 86 is spaced apart from the first pad 81, the first adhesive 85, and the ground terminal 93.

[0077] 4, the flexure 57 has a backing layer 111, a base layer 112, a conductive layer 113, and a cover layer 114. The backing layer 111 is an example of a metal plate. The base layer 112 is an example of a second insulating layer. The cover layer 114 is an example of a first insulating layer.

[0078] The backing layer 111, the base layer 112, the conductive layer 113, and the cover layer 114 are laminated in the Z direction in most parts of the flexure 57. Therefore, each of the first protruding portion 76 and the second protruding portion 77 partially has the backing layer 111, the base layer 112, the conductive layer 113, and the cover layer 114. Note that the flexure 57 may have, for example, a portion where the backing layer 111 is omitted and a portion where the base layer 112, the conductive layer 113, and the cover layer 114 are omitted.

[0079] The backing layer 111 is a metal plate made of a metal such as stainless steel. The backing layer 111 has two surfaces 111a and 111b. The surface 111a is formed to be approximately flat and faces the +Z direction. The surface 111b is located opposite the surface 111a. The surface 111b is formed to be approximately flat and faces the -Z direction. The surface 111b is exposed to the outside and forms the surface of the flexure 57 opposite the outer surface 61a.

[0080] The base layer 112 and the cover layer 114 are made of an insulator such as polyimide (PI). The material of the base layer 112 is the same as the material of the cover layer 114. Note that the material of the base layer 112 and the material of the cover layer 114 may be different from each other.

[0081] The base layer 112 covers the surface 111a of the backing layer 111 and is fixed to the surface 111a. The base layer 112 may be adhered to the surface 111a by, for example, an adhesive layer, or may be directly attached to the surface 111a.

[0082] The base layer 112 has two surfaces 112a and 112b. The surface 112a is formed to be substantially flat and faces the +Z direction. The surface 112b is located on the opposite side to the surface 112a. The surface 112b is formed to be substantially flat and faces the -Z direction. The surface 112b is fixed to the surface 111a of the backing layer 111.

[0083] The conductive layer 113 is disposed on the surface 112a of the base layer 112. The conductive layer 113 is made of a conductor such as copper. The conductive layer 113 is thinner than the backing layer 111. The thickness of the conductive layer 113 is, for example, 14 to 20 μm. Note that the thicknesses of the backing layer 111 and the conductive layer 113 are not limited to this example.

[0084] The conductive layer 113 has, for example, a plurality of wiring patterns and pads. The conductive layer 113 has a first pad 81 and a second pad 82. Furthermore, the conductive layer 113 has a pad connected to the magnetic head 51, a pad connected to the FPC 37, and a wiring pattern connecting the plurality of pads to each other. Note that the conductive layer 113 is not limited to this example.

[0085] The cover layer 114 covers the surface 112a of the base layer 112 and at least a portion of the conductive layer 113, and is fixed to the base layer 112 and the conductive layer 113. That is, the cover layer 114 covers at least a portion of the conductive layer 113, and covers the base layer 112 at a position where the conductive layer 113 is not provided. The cover layer 114 may be adhered to the surface 112a by, for example, an adhesive layer, or may be directly attached to the surface 112a.

[0086] In the flexure 57, the base layer 112 is located between the backing layer 111 and the cover layer 114. Furthermore, the conductive layer 113 is located between the base layer 112 and the cover layer 114. Note that the flexure 57 may be a multilayer substrate having a plurality of insulating layers and a plurality of conductive layers instead of the base layer 112.

[0087] The cover layer 114 has two surfaces 114a and 114b. The surface 114a is exposed to the outside and forms a part of the outer surface 61a of the flexure 57. The surface 114b is located opposite the surface 114a. The surface 114b is fixed to the surface 112a of the base layer 112 and the conductive layer 113.

[0088] A first exposure hole 115 and a second exposure hole 116 are provided in the cover layer 114. The first exposure hole 115 and the second exposure hole 116 each penetrate the cover layer 114 substantially in the Z direction and open to the surfaces 114a and 114b.

[0089] The first exposure hole 115 is provided in the first protruding portion 76 and exposes at least a portion of the first pad 81 to the outside of the flexure 57. The surface of the first pad 81 exposed by the first exposure hole 115 forms a part of the outer surface 61a of the flexure 57.

[0090] The second exposure hole 116 is provided in the second protruding portion 77 and exposes at least a portion of the second pad 82 to the outside of the flexure 57. The surface of the second pad 82 exposed by the second exposure hole 116 forms a part of the outer surface 61a of the flexure 57. In other words, the outer surface 61a includes the surface 114a of the cover layer 114, the surface of the first pad 81 exposed by the first exposure hole 115, and the surface of the second pad 82 exposed by the second exposure hole 116.

[0091] A plurality of through holes 121, 122 are provided in the first protruding portion 76. The plurality of through holes 121 are an example of first through holes. The plurality of through holes 122 are an example of first holes. Each of the plurality of through holes 121, 122 penetrates the flexure 57 in the first protruding portion 76 approximately in the Z direction and opens to the first pad 81. In this embodiment, the through holes 121, 122 penetrate the base layer 112 and the first pad 81 of the conductive layer 113.

[0092] The multiple through holes 121 are arranged at positions where the lower membrane 101 and the middle membrane 106 overlap the first pad 81 in the -Z direction. Moreover, the multiple through holes 121 in this embodiment are arranged between the end of the first pad 81 and the center of the first pad 81 in the -Y direction.

[0093] The multiple through-holes 122 are disposed at positions spaced apart from the tunica media 106 in the +Y direction along the outer surface 61a. In other words, the tunica media 106 does not overlap the through-holes 122 in the -Z direction. The +Y direction is an example of a fourth direction.

[0094] Each of the multiple through holes 121, 122 is formed, for example, in a substantially elliptical shape extending substantially in the X direction. The multiple through holes 121, 122 are arranged at intervals in the substantially Y direction. The shape of the multiple through holes 121, 122 may be other shapes such as a circle, a square, or a rectangle.

[0095] The cross-sectional area of ​​through hole 121 is larger than the cross-sectional area of ​​through hole 122. The cross-sectional areas of through holes 121, 122 are the areas of the cross sections of through holes 121, 122 perpendicular to the direction in which through holes 121, 122 extend (Z direction).

[0096] In this embodiment, the cross-sectional area of ​​each of the multiple through holes 121 is larger than the cross-sectional area of ​​each of the multiple through holes 122. Furthermore, the total cross-sectional area of ​​the multiple through holes 121 is larger than the total cross-sectional area of ​​the multiple through holes 122. Note that the cross-sectional areas of the through holes 121 and 122 are not limited to this example. The cross-sectional area of ​​the through hole 121 may be the same as or smaller than the cross-sectional area of ​​the through hole 122.

[0097] In the first protruding portion 76, a through hole 123 is provided in the backing layer 111. The through hole 123 is an example of a third through hole. The through hole 123 penetrates the backing layer 111 and communicates with the multiple through holes 121, 122.

[0098] An edge 123a of the through hole 123 is spaced apart from the edges 121a of the multiple through holes 121 and surrounds the multiple through holes 121. The edge 123a of the through hole 123 is spaced apart from an edge 111c of the backing layer 111. That is, the through hole 123 is formed (defined, partitioned) by the endless edge 123a.

[0099] A plurality of through holes 125, 126 are provided in the second protruding portion 77. The plurality of through holes 125 are an example of second through holes. The plurality of through holes 126 are an example of second holes. Each of the plurality of through holes 125, 126 penetrates the flexure 57 in the second protruding portion 77 approximately in the Z direction and opens to the second pad 82. In this embodiment, the through holes 125, 126 penetrate the base layer 112 and the second pad 82 of the conductive layer 113.

[0100] The multiple through holes 125 are arranged at positions where the lower film 105 and the upper film 102 overlap the second pad 82 in the -Z direction. Moreover, the multiple through holes 125 in this embodiment are arranged between an end of the second pad 82 in the +Y direction and the center of the second pad 82. The multiple through holes 126 are arranged at positions spaced apart from the upper film 102 in the -Y direction along the outer surface 61a.

[0101] Each of the multiple through holes 125, 126 is formed, for example, in a substantially oval shape extending substantially in the X direction. The multiple through holes 125, 126 are arranged at intervals substantially in the Y direction. Note that the shape of the multiple through holes 125, 126 may be other shapes such as a circle, a square, or a rectangle.

[0102] The cross-sectional area of ​​the through holes 125, 126 is smaller than the cross-sectional area of ​​the through hole 121. In this embodiment, the cross-sectional area of ​​each of the multiple through holes 125, 126 is smaller than the cross-sectional area of ​​each of the multiple through holes 121. Furthermore, the total cross-sectional area of ​​the multiple through holes 125 is smaller than the total cross-sectional area of ​​the multiple through holes 121. Note that the cross-sectional area of ​​the through holes 125, 126 is not limited to this example. The cross-sectional area of ​​the through holes 125, 126 may be the same as or larger than the cross-sectional area of ​​the through hole 121.

[0103] In the second protruding portion 77, a through hole 127 is provided in the backing layer 111. The through hole 127 penetrates the backing layer 111 and communicates with the multiple through holes 125, 126. An edge 127a of the through hole 127 is spaced apart from the edges 125a of the multiple through holes 125 and surrounds the multiple through holes 125. The edge 127a of the through hole 127 is spaced apart from an edge 111c of the backing layer 111.

[0104] The first adhesive 85 is partially contained in the through holes 121, 122. It is sufficient that even a small amount of the first adhesive 85 enters the through hole 121. A portion of the first adhesive 85 adheres to the flexure 57 at a position where the backing layer 111 overlaps in the +Z direction. That is, a portion of the first adhesive 85 adheres to a portion of the flexure 57 where the backing layer 111 is provided and has high rigidity. The +Z direction is the direction in which the outer surface 61a faces, and is an example of the sixth direction.

[0105] The second adhesive 86 is partially contained in the through holes 125, 126. It is sufficient that even a small amount of the second adhesive 86 enters the through hole 125. A part of the second adhesive 86 adheres to the flexure 57 at a position where the backing layer 111 overlaps in the +Z direction.

[0106] In this embodiment, the first adhesive 85 remains in the through holes 121 and 122 and is spaced apart from the through hole 123. The second adhesive 86 remains in the through holes 125 and 126 and is spaced apart from the through hole 127. The first adhesive 85 and the second adhesive 86 may be partially contained in the through holes 123 and 127.

[0107] The first pad 81 is set to a ground potential. For example, the first pad 81 is electrically connected to a ground plane. Therefore, the ground terminal 93 is also set to a ground potential.

[0108] The second pad 82 is electrically connected to a controller of the PCB 17 via the flexure 57 and the FPC 37. The controller applies an electrical signal to the second pad 82 to adjust the position of the magnetic head 51.

[0109] When an electric signal is applied to the second pad 82, a potential difference is generated between the signal terminal 94 and the ground terminal 93. This potential difference causes the first piezoelectric body 91 and the second piezoelectric body 92 to deform, causing the second MA 66 to expand and contract in the Y direction. In other words, the second MA 66 expands or contracts in the Y direction (+Y direction and -Y direction) when a voltage is applied to the lower film 105.

[0110] The following describes an example of a method for mounting the second MA 66 on the flexure 57 as part of a method for manufacturing the HDD 10. Note that the method for mounting the second MA 66 is not limited to the following method, and other methods may be used.

[0111] First, a first adhesive 85 is applied to the first pad 81, and a second adhesive 86 is applied to the second pad 82. At this time, the first adhesive 85 and the second adhesive 86 are not hardened and have fluidity. The first adhesive 85 may be applied to the lower film 101 of the ground terminal 93. The second adhesive 86 may be applied to the lower film 105 of the signal terminal 94.

[0112] Next, the second MA 66 is placed on the flexure 57 by, for example, a mounter. The mounter moves the second MA 66 closer to the flexure 57 until the distance between the second MA 66 and the flexure 57 reaches a predetermined value.

[0113] As the second MA 66 approaches the flexure 57, the first adhesive 85 is squashed between the first pad 81 and the lower film 101 of the ground terminal 93. The first adhesive 85 spreads along the second MA 66 and the outer surface 61a of the flexure 57. As a result, the first adhesive 85 adheres to the lateral film 103 of the ground terminal 93. The first adhesive 85 may also adhere to the side surfaces 66a and 66b of the second MA 66.

[0114] A portion of the first adhesive 85 flows into the through holes 121, 122. In other words, a portion of the first adhesive 85 is forced into the through holes 121, 122 by the second MA 66. Due to the resistance in the through holes 121, 122, the amount of the first adhesive 85 that flows into the through holes 121, 122 is less than the amount that spreads along the second MA 66 and the flexure 57. Note that the flow of the first adhesive 85 is not limited to this example.

[0115] The through holes 121 and 122 accommodate a portion of the first adhesive 85, thereby reducing the amount of the first adhesive 85 spreading along the second MA 66 and the flexure 57. Therefore, the through holes 121 and 122 prevent the first adhesive 85 moving along the side surfaces 66a and 66b of the second MA 66 from reaching the middle membrane 106 of the signal terminal 94 exposed on the side surfaces 66a and 66b.

[0116] Similarly, as the second MA 66 approaches the flexure 57, the second adhesive 86 is crushed between the second pad 82 and the lower film 105 of the signal terminal 94. The second adhesive 86 spreads along the second MA 66 and the outer surface 61a of the flexure 57. As a result, the second adhesive 86 adheres to the lateral film 107 of the signal terminal 94. The second adhesive 86 may also adhere to the side surfaces 66a and 66b of the second MA 66.

[0117] A portion of the second adhesive 86 flows into the through holes 125, 126. Because of the resistance in the through holes 125, 126, the amount of the second adhesive 86 that flows into the through holes 125, 126 is less than the amount that spreads along the second MA 66 and the flexure 57. Note that the flow of the second adhesive 86 is not limited to this example.

[0118] The through holes 125, 126 accommodate a portion of the second adhesive 86, thereby reducing the amount of the second adhesive 86 spreading along the second MA 66 and the flexure 57. Therefore, the through holes 125, 126 prevent the second adhesive 86 moving along the side surfaces 66a, 66b of the second MA 66 from reaching the upper film 102 of the ground terminal 93 exposed on the side surfaces 66a, 66b.

[0119] Next, the first adhesive 85 and the second adhesive 86 are cured. Furthermore, the flexure 57 is washed, for example, with a cleaning liquid to remove particles generated from the first adhesive 85 and the second adhesive 86. This completes the mounting of the second MA 66 on the flexure 57.

[0120] The through holes 121, 122, 123, 125, 126, and 127 can be formed by various methods. For example, the through holes 121, 122, 123, 125, 126, and 127 are formed by processing the backing layer 111, the base layer 112, and the conductive layer 113 by etching when the flexure 57 is manufactured.

[0121] In the HDD 10 according to the first embodiment described above, the second MA 66 has a first piezoelectric body 91, a lower film 101, a lower film 105, and a middle film 106. The lower film 101 is provided on a lower surface 91a of the first piezoelectric body 91. The lower film 105 is provided on the lower surface 91a at a position spaced apart from the lower film 101 in the -Y direction along the lower surface 91a. The middle film 106 is provided on an upper surface 91b of the first piezoelectric body 91 located on the opposite side of the lower surface 91a and is connected to the lower film 105. The flexure 57 has an outer surface 61a, a first pad 81, and a second pad 82. The outer surface 61a faces the lower film 101 and the lower film 105. The first pad 81 is provided on the outer surface 61a. The second pad 82 is provided on the outer surface 61a at a position spaced from the first pad 81 in the -Y direction. A through hole 121 is provided in the flexure 57. The through hole 121 opens in the first pad 81 at a position where the lower film 101 and the middle film 106 overlap in the -Z direction in which the lower surface 91a faces. In other words, the through hole 121 opens in the first pad 81 between the end of the first pad 81 and the center of the first pad 81 in the -Y direction. The conductive first adhesive 85 bonds the first pad 81 and the lower film 101 and is partially contained in the through hole 121.

[0122] The middle film 106 is connected to the lower film 105. Therefore, the middle film 106 is generally spaced in the -Y direction from the end of the upper surface 91b in the direction opposite to the +Y direction. When the second MA 66 is bonded to the first pad 81 by the first adhesive 85, for example, the first adhesive 85 applied in advance to the first pad 81 or the lower film 101 is crushed between the first pad 81 and the lower film 101. At this time, the first adhesive 85 can be prevented from spreading along the second MA 66 until it reaches the middle film 106 by partially flowing into the through hole 121. Therefore, the HDD 10 of this embodiment can prevent the first adhesive 85 from shorting the lower film 101 and the middle film 106, and thus can prevent the deterioration of the electrical properties of the second MA 66 due to the short circuit. The HDD 10 can be easily manufactured and the yield can be improved because the short circuit during manufacturing can be easily prevented. Further, the first adhesive 85 is partially accommodated in the through hole 121 and bonds the first pad 81 and the lower film 101. That is, the through hole 121 increases the contact area between the flexure 57 and the first adhesive 85. Therefore, the first adhesive 85 can attach the second MA 66 to the flexure 57 more firmly than when it is simply attached to the surface of the first pad 81. Therefore, in the HDD 10 of this embodiment, even if the flexure 57 has the through hole 121, it is possible to suppress a decrease in the strength of the suspension 52 including the second MA 66 and the flexure 57.

[0123] The second MA 66 has a side surface 66a. The side surface 66a is provided along the lower surface 91a and at an end of the second MA 66 in the +X direction perpendicular to the -Y direction. The middle film 106 is exposed to the outside of the second MA 66 at least at the side surface 66a. If the first adhesive 85 spreads along the side surface 66a until it reaches the exposed middle film 106, there is a risk that the lower film 101 and the middle film 106 will be short-circuited. However, in the HDD 10 of this embodiment, the first adhesive 85 partially flows into the through hole 121, so that it is possible to prevent the first adhesive 85 from short-circuiting the lower film 101 and the middle film 106.

[0124] A through hole 122 is provided in the flexure 57. The through hole 122 opens to the first pad 81 at a position separated from the middle film 106 in the +Y direction opposite to the -Y direction along the outer surface 61a. When the second MA 66 is bonded to the first pad 81 by the first adhesive 85, the first adhesive 85 partially flows into the through hole 122, thereby preventing the first adhesive 85 from spreading along the second MA 66 until it reaches the middle film 106. Therefore, the HDD 10 of this embodiment can more reliably prevent the first adhesive 85 from shorting the lower film 101 and the middle film 106.

[0125] The through-holes 122 penetrate the flexure 57. This allows the first adhesive 85 to easily flow into the through-holes 122. Therefore, the first adhesive 85 can be prevented from spreading along the second MA 66 until it reaches the middle membrane 106.

[0126] The cross-sectional area of ​​the through hole 121 is larger than the cross-sectional area of ​​the through hole 122. This reduces the amount of the first adhesive 85 flowing into the through hole 122 at a position away from the middle membrane 106. For example, more of the first adhesive 85 spreads at a position away from the middle membrane 106, so that more of the first adhesive 85 can adhere to the lateral membrane 103. Therefore, the HDD 10 of this embodiment can suppress a reduction in the contact area between the second MA 66 and the first adhesive 85, and suppress a decrease in the strength of the suspension 52 including the second MA 66 and the flexure 57.

[0127] The second MA 66 has a second piezoelectric body 92 and an upper film 102. A lower surface 92a of the second piezoelectric body 92 is attached to the upper surface 91b. The upper film 102 is provided on an upper surface 92b of the second piezoelectric body 92 located opposite to the lower surface 92a, and is connected to the lower film 101. A through hole 125 is provided in the flexure 57. The through hole 125 opens to the second pad 82 at a position where the lower film 105 and the upper film 102 overlap in the -Z direction. The second adhesive 86 is partially accommodated in the through hole 125. When the second MA 66 is bonded to the second pad 82 by the second adhesive 86, the second adhesive 86 is crushed between the second pad 82 and the lower film 105. At this time, the second adhesive 86 partially flows into the through-hole 125, thereby preventing the second adhesive 86 from spreading along the second MA 66 until it reaches the upper film 102. Therefore, the HDD 10 of this embodiment can prevent the second adhesive 86 from shorting the lower film 105 and the upper film 102. Furthermore, even if the flexure 57 has the through-hole 125, the HDD 10 of this embodiment can prevent a decrease in strength of the suspension 52 including the second MA 66 and the flexure 57.

[0128] A through hole 126 is provided in the flexure 57. The through hole 126 opens to the second pad 82 at a position separated from the upper film 102 in the −Y direction along the outer surface 61a. When the second MA 66 is bonded to the second pad 82 by the second adhesive 86, the second adhesive 86 partially flows into the through hole 126, thereby preventing the second adhesive 86 from spreading along the second MA 66 until it reaches the upper film 102. Therefore, the HDD 10 of this embodiment can more reliably prevent the second adhesive 86 from shorting the lower film 105 and the upper film 102.

[0129] The cross-sectional area of ​​the through hole 125 is smaller than the cross-sectional area of ​​the through hole 121. This reduces the amount of the second adhesive 86 flowing into the through hole 125. Therefore, the HDD 10 of this embodiment can suppress the reduction in the contact area between the second MA 66 and the second adhesive 86, and can suppress the reduction in the strength of the suspension 52 including the second MA 66 and the flexure 57. Since the upper film 102 is provided on the upper surface 92b of the second piezoelectric body 92, the distance between the lower film 105 and the upper film 102 is longer than the distance between the lower film 101 and the middle film 106. Therefore, the HDD 10 of this embodiment can suppress the second adhesive 86 from shorting the lower film 105 and the upper film 102 even if the amount of the second adhesive 86 flowing into the through hole 125 is small.

[0130] The flexure 57 has a backing layer 111, a cover layer 114, a base layer 112, and a conductive layer 113. The base layer 112 is located between the backing layer 111 and the cover layer 114. The conductive layer 113 is located between the cover layer 114 and the base layer 112. The conductive layer 113 has a first pad 81. The through hole 121 penetrates the base layer 112 and the first pad 81. The backing layer 111 is provided with a through hole 123 that communicates with the through hole 121. An edge 123a of the through hole 123 is separated from an edge 121a of the through hole 121 and surrounds the through hole 121. This prevents the first adhesive 85 from contacting the backing layer 111 even if it passes through the through hole 121. That is, the HDD 10 of this embodiment can prevent the first adhesive 85 from causing a short circuit between the lower film 101 and the backing layer 111.

[0131] A part of the first adhesive 85 adheres to the flexure 57 at a position where the backing layer 111 overlaps in the +Z direction in which the outer surface 61a faces. That is, the first adhesive 85 bonds the second MA 66 to a portion of the flexure 57 whose rigidity has been improved by the backing layer 111. Therefore, the force generated by the second MA 66 is transmitted to the flexure 57 more efficiently. Therefore, in the HDD 10 of this embodiment, the second MA 66 can stably deform the flexure 57, and thus the position of the magnetic head 51 can be stably adjusted.

[0132] The first pad 81 is set to a ground potential. The second MA 66 is configured to expand or contract in the +Y direction by applying a voltage to the lower film 105. Therefore, even if the first adhesive 85 passes through the through hole 121 and adheres to, for example, the backing layer 111, it is possible to suppress the first adhesive 85 from affecting the operations of the first piezoelectric body 91 and the second piezoelectric body 92.

[0133] Second Embodiment The second embodiment will be described below with reference to Fig. 6. In the following description of the embodiments, components having the same functions as components already described are given the same reference numerals as the components already described, and further description may be omitted. Also, components given the same reference numerals do not necessarily have all the same functions and properties, and may have different functions and properties according to each embodiment.

[0134] 6 is an exemplary cross-sectional view showing a part of the HGA 36 according to the second embodiment. As shown in FIG. 6, the first protrusion 76 of the second embodiment is provided with a plurality of holes 201 instead of the plurality of through holes 122. The holes 201 are an example of a first hole. The holes 201 are substantially equal to the through holes 122, except for the points described below.

[0135] Furthermore, the second protrusion 77 of the second embodiment is provided with a plurality of holes 205 instead of the plurality of through holes 126. The holes 205 are an example of a second hole. The holes 205 are substantially equal to the through holes 126, except as described below.

[0136] The multiple holes 201 penetrate the first pad 81 of the conductive layer 113. The multiple holes 205 penetrate the second pad 82 of the conductive layer 113. On the other hand, the holes 201 and 205 do not penetrate the base layer 112. The base layer 112 blocks the multiple holes 201 and 205. Therefore, the hole 201 is a recess that opens to the first pad 81, and the hole 205 is a recess that opens to the second pad 82.

[0137] In the HDD 10 of the second embodiment described above, the hole 201 penetrates the first pad 81. The base layer 112 closes the hole 201. That is, the hole 201 is shallower than the through hole 121. This reduces the amount of the first adhesive 85 that flows into the hole 201 at a position away from the middle membrane 106. Therefore, the HDD 10 of this embodiment can suppress a reduction in the contact area between the second MA 66 and the first adhesive 85, and can suppress a decrease in the strength of the suspension 52 including the second MA 66 and the flexure 57.

[0138] (Third embodiment) The third embodiment will be described below with reference to Fig. 7 and Fig. 8. Fig. 7 is an exemplary plan view showing a part of an HGA 36 according to the third embodiment. Fig. 8 is an exemplary cross-sectional view showing a part of an HGA 36 of the third embodiment along line F8-F8 in Fig. 7.

[0139] 7, each of the two MA mounting portions 71 in the third embodiment has a first protrusion 301 and a second protrusion 302 instead of the first protrusion 76 and the second protrusion 77. The first protrusion 301 and the second protrusion 302 are substantially equal to the first protrusion 76 and the second protrusion 77, except for the points described below. The first protrusion 301 is an example of a protrusion.

[0140] The first protrusion 301 protrudes from the peripheral portion 75 in the -Y direction, and is provided with a first pad 81. The second protrusion 302 protrudes from the peripheral portion 75 in the +Y direction, and is provided with a second pad 82.

[0141] In the X direction, the width of the first protrusion 301 is smaller than the width of the second MA 66. In addition, in the X direction, the width of the second protrusion 302 is smaller than the width of the second MA 66. The X direction is a direction along the lower surface 91a and perpendicular to the -Y direction, and is an example of a fifth direction.

[0142] 8, in the X direction, the width of the backing layer 111 of the first protrusion 301 is smaller than the width of the base layer 112 of the first protrusion 301. An edge 111c of the backing layer 111 is spaced apart from an edge 112c of the base layer 112. Similarly, in the X direction, the width of the backing layer 111 of the second protrusion 302 is smaller than the width of the base layer 112 of the second protrusion 302.

[0143] When the second MA 66 is placed on the flexure 57, the squashed first adhesive 85 spreads along the outer surface 61a of the second MA 66 and the flexure 57. The first adhesive 85 reaches the end of the first protrusion 301 in the X direction before reaching the side surfaces 66a and 66b of the second MA 66.

[0144] Between the end of the first protrusion 301 in the X direction and the side surfaces 66a, 66b of the second MA 66, the second MA 66 is exposed and not covered by the first protrusion 301. Therefore, the flow speed of the first adhesive 85 that is crushed and spreads is reduced, and the first adhesive 85 is less likely to reach the side surfaces 66a, 66b of the second MA 66.

[0145] A part of the first adhesive 85 spreads along the first protruding portion 301 in the X direction. For example, the first adhesive 85 spreads to the edge 112c of the base layer 112. However, because the edge 112c of the base layer 112 is separated from the edge 111c of the backing layer 111, it is difficult for the first adhesive 85 to reach the backing layer 111.

[0146] In the HDD 10 of the third embodiment described above, the flexure 57 has a peripheral portion 75 and a first protruding portion 301 that protrudes from the peripheral portion 75 in the -Y direction and is provided with a first pad 81. In the X direction along the lower surface 91a and perpendicular to the -Y direction, the width of the first protruding portion 301 is smaller than the width of the second MA 66. When the second MA 66 is bonded to the first pad 81 by the first adhesive 85, the first adhesive 85 is crushed between the first pad 81 and the lower film 101. At this time, the first adhesive 85 partially spreads along the outer surface 61a of the first protruding portion 301 and reaches the end of the first protruding portion 301. Outside the end of the first protruding portion 301, the lower surface 91a of the second MA 66 is not covered by the first protruding portion 301. Therefore, the spread of the crushed first adhesive 85 is reduced when it reaches the end of the first protruding portion 301. That is, the first adhesive 85 can be prevented from spreading along the second MA 66 until it reaches the middle film 106. Therefore, the HDD 10 of this embodiment can prevent the first adhesive 85 from shorting the lower film 101 and the middle film 106.

[0147] In the X direction, the width of the backing layer 111 is smaller than the width of the base layer 112. As a result, even if the squashed first adhesive 85 reaches, for example, the edge 112c of the base layer 112, it is still separated from the backing layer 111. Therefore, the HDD 10 of this embodiment can prevent the first adhesive 85 from shorting the lower film 101 and the backing layer 111.

[0148] In the above embodiment, the second MA 66 has been mainly described. However, at least one of the through holes 121, 122, 123, 125, 126, 127 and the holes 201, 205 may be provided on the pad on which the first MA 65 is mounted, similar to the first pad 81 and the second pad 82. Also, the through holes 122, 125, 126, 127 and the holes 201, 205 may be omitted.

[0149] Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and spirit of the invention, and are included in the scope of the invention and its equivalents described in the claims. [Explanation of symbols]

[0150] 10...hard disk drive (HDD), 12...magnetic disk, 51...magnetic head, 57...flexure, 61a...outer surface, 66...second microactuator (MA), 66a...side surface, 75...periphery, 76, 301...first protrusion, 77, 302...second protrusion, 81...first pad, 82...second pad, 85...first adhesive, 86...second adhesive, 91...first piezoelectric element, 91a...lower surface, 91b...upper surface, 92...second piezoelectric body, 92a...lower surface, 92b...upper surface, 101...lower film, 102...upper film, 105...lower film, 106...middle film, 111...backing layer, 111c...edge, 112...base layer, 113...conductive layer, 114...cover layer, 121, 122, 123, 125, 126, 127...through holes, 121a, 123a, 125a, 127a...edge, 201, 205...holes.

Claims

1. A magnetic disk; a magnetic head configured to read and write information to the magnetic disk; a piezoelectric element including: a first piezoelectric body; a first electrode provided on a first surface of the first piezoelectric body; a second electrode provided on the first surface at a position spaced apart from the first electrode in a first direction along the first surface; and a third electrode provided on a second surface of the first piezoelectric body located opposite the first surface and connected to the second electrode; a flexure having an outer surface facing the first electrode and the second electrode, a first pad provided on the outer surface, and a second pad provided on the outer surface at a position spaced apart from the first pad in the first direction, the flexure having a first through hole opening into the first pad at a position where the first electrode and the third electrode overlap in the second direction in which the first surface faces, and on which the magnetic head is mounted; a conductive first bonding body that bonds the first pad and the first electrode and is partially accommodated in the first through hole; a conductive second bonding body that bonds the second pad and the second electrode; A disk device comprising:

2. the piezoelectric element has an end surface provided along the first surface and at an end of the piezoelectric element in a third direction perpendicular to the first direction; the third electrode is exposed to the outside of the piezoelectric element at least at the end surface; 2. The disk device according to claim 1.

3. The flexure has a first hole, the first hole opens into the first pad at a position spaced apart from the third electrode in a fourth direction opposite to the first direction along the outer surface; 2. The disk device according to claim 1.

4. The first hole penetrates the flexure.

4. The disk device according to claim 3.

5. the flexure has a metal plate, a first insulating layer, a second insulating layer located between the metal plate and the first insulating layer, and a conductive layer located between the first insulating layer and the second insulating layer; the conductive layer has the first pad; the first hole passes through the first pad; the second insulating layer fills the first hole; 4. The disk device according to claim 3.

6. The cross-sectional area of ​​the first through hole is larger than the cross-sectional area of ​​the first hole.

4. The disk device according to claim 3.

7. The piezoelectric element has a second piezoelectric body and a fourth electrode, a third surface of the second piezoelectric body is attached to the second surface; the fourth electrode is provided on a fourth surface of the second piezoelectric body located opposite to the third surface and is connected to the first electrode; a second through hole is provided in the flexure, the second through hole opening into the second pad at a position where the second electrode and the fourth electrode overlap in the second direction; The second bonding body is partially accommodated in the second through hole.

2. The disk device according to claim 1.

8. The flexure is provided with a second hole, The second hole is open to the second pad at a position spaced apart from the fourth electrode in the first direction along the outer surface.

8. The disk device according to claim 7.

9. The cross-sectional area of ​​the second through hole is smaller than the cross-sectional area of ​​the first through hole.

8. The disk device according to claim 7.

10. the flexure has a base and a protruding portion protruding from the base in the first direction and provided with the first pad; In a fifth direction along the first surface and perpendicular to the first direction, a width of the protrusion is smaller than a width of the piezoelectric element.

2. The disk device according to claim 1.

11. the protrusion portion has a metal plate, a first insulating layer, a second insulating layer located between the metal plate and the first insulating layer, and a conductive layer located between the first insulating layer and the second insulating layer, the conductive layer has the first pad; In the fifth direction, the width of the metal plate is smaller than the width of the second insulating layer. The disk device according to claim 10.

12. the flexure has a metal plate, a first insulating layer, a second insulating layer located between the metal plate and the first insulating layer, and a conductive layer located between the first insulating layer and the second insulating layer; the conductive layer has the first pad; the first through hole penetrates the second insulating layer and the first pad; a third through hole communicating with the first through hole is provided in the metal plate; an edge of the third through hole is spaced apart from an edge of the first through hole and surrounds the first through hole; 2. The disk device according to claim 1.

13. the flexure has a metal plate, a first insulating layer, a second insulating layer located between the metal plate and the first insulating layer, and a conductive layer located between the first insulating layer and the second insulating layer; a portion of the first bonding body is attached to the flexure at a position where the metal plate overlaps in a sixth direction in which the outer surface faces; 2. The disk device according to claim 1.

14. the first pad is set to a ground potential; The piezoelectric element is configured to expand or contract in the first direction by applying a voltage to the second electrode.

2. The disk device according to claim 1.

15. A magnetic disk; a magnetic head configured to read and write information to the magnetic disk; a piezoelectric element including: a first piezoelectric body; a first electrode provided on a first surface of the first piezoelectric body; a second electrode provided on the first surface at a position spaced apart from the first electrode in a first direction along the first surface; and a third electrode provided on a second surface of the first piezoelectric body located opposite the first surface and connected to the second electrode; a flexure having an outer surface facing the first electrode and the second electrode, a first pad provided on the outer surface, and a second pad provided on the outer surface at a position spaced apart from the first pad in the first direction, a first through hole opening into the first pad between an end of the first pad and a center of the first pad in the first direction, and on which the magnetic head is mounted; a conductive first bonding body that bonds the first pad and the first electrode and is partially accommodated in the first through hole; a conductive second bonding body that bonds the second pad and the second electrode; A disk device comprising:

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