Disk device

Abstract

Provided is a disk device capable of suppressing short-circuiting of two electrodes of a piezoelectric element by a joined body. A disk device according to an embodiment includes a magnetic disk, a magnetic head, a piezoelectric element, a flexible member, a first joined body, and a second joined body. The piezoelectric element includes 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 flexible member has an outer surface, and a first pad and a second pad provided on the outer surface, and is provided with a first through hole that opens in the first pad at a position where the first electrode and the third electrode overlap. The first joined body joins 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 to each other.

Description

[0001] This application claims the priority of Japanese Patent Application No. 2023-121461 (filing date: July 26, 2023) as a basic application. The present application incorporates the entire contents of the basic application by reference. Technical Field

[0002] An embodiment of the present invention relates to a disk device. Background Art

[0003] A disk device such as a hard disk drive has a magnetic disk and a magnetic head for reading and writing information on 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 mounted on the flexure by a bonding body such as a conductive adhesive.

[0004] In a piezoelectric element, a piezoelectric body is arranged between two electrodes. When one electrode of the piezoelectric element is mounted on a pad of a flexible member, the bonded body is compressed (squeezed) between the piezoelectric element and the flexible member. The compressed bonded body may spread along the side of the piezoelectric element to the other electrode. Summary of the invention

[0005] An embodiment of the present invention provides a disk device capable of preventing a bonded body from short-circuiting two electrodes of a piezoelectric element.

[0006] The disk device according to the embodiment includes a magnetic disk, a magnetic head, a piezoelectric element, a flexible member, a first conductive joint body, and a second conductive joint body. The magnetic head is configured to read and write information on 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 away from the first electrode in a first direction along the first surface, and a third electrode provided on the second surface of the first piezoelectric body on the opposite side of the first surface and connected to the second electrode. The flexible member includes 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 away from the first pad in the first direction, and a first through hole is provided on the flexible member, the first through hole is opened on the first pad at a position where the first electrode and the third electrode overlap in the second direction facing the first surface, and the magnetic head is mounted on the flexible member. The first bonding body bonds the first pad to the first electrode and is partially (partially) accommodated in the first through hole. The second bonding body bonds the second pad to the second electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1This is an exemplary perspective view showing an exploded view of the HDD according to the first embodiment.

[0008] Figure 2 This is an exemplary perspective view partially showing the HGA according to the first embodiment.

[0009] Figure 3 This is an exemplary plan view showing a part of the HGA according to the first embodiment.

[0010] Figure 4 A portion of the HGA of the first embodiment is connected along Figure 3 An exemplary cross-sectional view is shown along line F4-F4.

[0011] Figure 5 A portion of the HGA of the first embodiment is connected along Figure 3 An exemplary cross-sectional view is shown along line F5-F5.

[0012] Figure 6 This is an exemplary cross-sectional view showing a part of the HGA according to the second embodiment.

[0013] Figure 7 It is an illustrative plan view showing a part of the HGA according to the third embodiment.

[0014] Figure 8 A portion of the HGA of the third embodiment is connected along Figure 7 An exemplary cross-sectional view is shown along line F8-F8.

[0015] Description of Reference Numerals

[0016] 10 hard disk drive (HDD); 12 magnetic disk; 51 magnetic head; 57 flexible member; 61a outer surface; 66 second micro actuator (MA); 66a side surface; 75 peripheral portion; 76, 301 first protrusion; 77, 302 second protrusion; 81 first pad; 82 second pad; 85 first adhesive; 86 second adhesive; 91 first piezoelectric body; 91a lower surface; 91b upper surface; 92 The 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 substrate layer; 113 conductive layer; 114 covering layer; 121, 122, 123, 125, 126, 127 through holes; 121a, 123a, 125a, 127a edges; 201, 205 holes. DETAILED DESCRIPTION

[0017] (First embodiment)

[0018] Below, refer to Figures 1 to 5The first embodiment is described. In addition, in this specification, the components and descriptions of the components involved in the embodiment are sometimes recorded in multiple expressions. The components and their descriptions are just examples and are not limited to the descriptions in this specification. The components may also be identified by names different from the names in this specification. In addition, the components may also be described by expressions different from the descriptions in this specification.

[0019] In the following description, “suppress” is defined as, for example, preventing an event / phenomenon, action, or influence from occurring, or reducing the degree of an event / phenomenon, action, or influence.

[0020] Figure 1 This is an exemplary perspective view showing an exploded 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.

[0021] The HDD 10 has 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 loading mechanism 16, and a printed circuit board (PCB) 17. The magnetic disks 12 may also be referred to as disks or platters.

[0022] like Figure 1 As shown, in this specification, for convenience, a Z axis and a Z direction are defined. The Z axis is set along the thickness of the HDD 10. The Z direction is a direction along the Z axis, including a +Z direction indicated by an arrow of the Z axis and a -Z direction which is the opposite direction of the arrow of the Z axis.

[0023] The housing 11 includes 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 also be different from each other.

[0024] The base 21 is formed in a substantially rectangular box shape that is open in the +Z direction. The base 21 accommodates the plurality of magnetic disks 12 , the spindle motor 13 , the HSA 14 , the VCM 15 , and the ramp load mechanism 16 .

[0025] 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 orthogonal to the Z direction. The side walls 26 protrude from the edge of the bottom wall 25 in the substantially +Z direction and are formed in a substantially rectangular frame shape.

[0026] The inner cover 22 is attached to the end of the side wall 26 in the +Z direction by screws, for example, to close 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 welding, for example.

[0027] The inner cover 22 is provided with a vent 27. Furthermore, the outer cover 23 is provided with a vent 28. After the components are installed inside the base 21 and the inner cover 22 and the outer cover 23 are installed on the base 21, the air inside the housing 11 is extracted from the vents 27 and 28. Then, the inside of the housing 11 is filled with a gas different from the air.

[0028] The gas filled into the shell 11 is, for example, a low-density gas having a lower density than air, an inert gas having low reactivity, etc. For example, helium gas is filled into the shell 11. In addition, other fluids may be filled into the shell 11. In addition, the inside of the shell 11 may also be maintained at a vacuum, a low pressure close to a vacuum, or a negative pressure lower than the atmospheric pressure.

[0029] The vent 28 of the outer cover 23 is blocked by a seal 29. The seal 29 hermetically seals the vent 28, and restricts leakage of the fluid filled in the housing 11 from the vent 28 to the outside of the housing 11.

[0030] The plurality of magnetic disks 12 are formed in a disk shape and are arranged substantially perpendicular to the Z direction. The plurality of magnetic disks 12 are arranged with gaps therebetween in the Z direction. A magnetic recording layer is provided on the surface of the magnetic disk 12 .

[0031] The spindle motor 13 supports and integrally rotates the plurality of magnetic disks 12. The plurality of magnetic disks 12 are held by a hub of the spindle motor 13 by, for example, a circlip.

[0032] The housing 11 is provided with a support shaft 31 spaced apart from the magnetic disk 12. The support shaft 31 extends, for example, substantially in the +Z direction from the bottom wall 25 of the housing 11. The HSA 14 is rotatably supported by the support shaft 31.

[0033] The HSA 14 includes a carriage 35 , a plurality of head gimbal assemblies (HGAs) 36 , and a flexible printed circuit board (FPC) 37 . The carriage 35 includes an actuator block 41 and a plurality of arms 42 .

[0034] The actuator block 41 and the plurality of arms 42 are integrally formed of, for example, an aluminum alloy. In addition, the materials of the actuator block 41 and the arms 42 are not limited to this example.

[0035] The actuator block 41 is supported by the support shaft 31 via a bearing, for example, so as to be rotatable around the support shaft 31 . Thus, the carriage 35 is rotatable around the support shaft 31 .

[0036] The plurality of arms 42 protrude from the actuator block 41 in a direction substantially perpendicular to the Z direction and substantially in parallel. Alternatively, the HSA 14 may be divided so that the arm 42 protrudes from each of the plurality of actuator blocks 41 .

[0037] The plurality of arms 42 are arranged with gaps therebetween in the Z direction. When the carriage 35 including the arms 42 rotates in one direction about the support shaft 31, each of the plurality of arms 42 can enter a gap between two adjacent magnetic disks 12 among the plurality of magnetic disks 12. When the carriage 35 rotates in the other direction, each of the plurality of arms 42 can exit from a gap between two adjacent magnetic disks 12.

[0038] Figure 2 FIG. 2 is an exemplary perspective view showing a part of the HGA 36 of the first embodiment. Figure 2 As shown, in this specification, for convenience, an X-axis and a Y-axis are also defined. The X-axis, the Y-axis, and the Z-axis are orthogonal to each other. The Y-axis is provided along the arm 42. Furthermore, in this specification, an X direction and a Y direction are also defined. The X direction is a direction along the X-axis, including the +X direction indicated by the arrow of the X-axis and the -X direction which is the opposite direction of the arrow of the X-axis. The Y direction is a direction along the Y-axis, including the +Y direction indicated by the arrow of the Y-axis and the -Y direction which is the opposite direction of the arrow of the Y-axis.

[0039] The plurality of arms 42 protrude in the +Y direction from the actuator block 41. Therefore, the Y direction is the longitudinal direction of the arm 42. The X direction is the short-side direction of the arm 42. The X direction and the Y direction change as the carriage 35 rotates.

[0040] The plurality of HGAs 36 are attached to the tip of the arm 42 so as to protrude from the arm 42 in the substantially +Y direction. Thus, the plurality of HGAs 36 are arranged with gaps therebetween in the Z direction. The plurality of HGAs 36 each have a magnetic head 51 and a suspension 52. The magnetic head 51 may also be called a slider.

[0041] The magnetic head 51 records and reproduces information on a corresponding one of the plurality of magnetic disks 12. In other words, the magnetic head 51 reads and writes information on the magnetic disk 12.

[0042] The suspension 52 is attached to the arm 42 and holds the magnetic head 51. The suspension 52 includes a base plate 55, a load beam 56, and a flexure 57.

[0043] The base plate 55 and the load beam 56 are made of, for example, stainless steel (SUS). 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.

[0044] The base plate 55 is formed in a substantially rectangular plate shape arranged substantially orthogonal to the Z direction. The base plate 55 is attached to the tip portion of the arm 42 by caulking, for example.

[0045] The load beam 56 is formed in a plate shape 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 substantially in the +Y direction.

[0046] The flexible member 57 is a flexible printed wiring board formed in a long and thin strip shape and has, for example, a universal joint portion 61 and a suspension tail 62 .

[0047] The gimbal portion 61 is provided at the 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 mounted on the load beam 56 so that the portion of the gimbal portion to which the magnetic head 51 is mounted is rotatable.

[0048] The suspension tail 62 extends from the universal joint portion 61 toward the actuator block 41. In addition, other parts may be provided between the universal joint portion 61 and the suspension tail 62.

[0049] -The end of the suspension tail 62 in the Y direction and Figure 1 The FPC 37 is connected to one end of the FPC 37 mounted on the actuator block 41. The other end of the FPC 37 is connected to a connector provided on the bottom wall 25, for example.

[0050] 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 to a desired position along the magnetic disk 12.

[0051] The VCM 15 has a voice coil, a pair of yokes, and a magnet provided on the yokes. The voice coil is held by the actuator block 41. When the magnetic head 51 moves to the outer edge of the magnetic disk 12 due to the rotation of the carriage 35 caused by the VCM 15, the ramp loading mechanism 16 holds the magnetic head 51 at a position away from the magnetic disk 12.

[0052] The PCB 17 is, for example, a rigid substrate such as a glass epoxy substrate, a multi-layer substrate, or a build-up substrate, etc. The PCB 17 is disposed outside the housing 11 and mounted on the bottom wall 25 .

[0053] Various electronic components such as a relay connector electrically connected to the FPC 37, an interface (I / F) connector connected to a host computer, and a controller for controlling the operation of the HDD 10 are mounted on the PCB 17. 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 controls the position of the magnetic head 51 by driving the VCM 15.

[0054] like Figure 2 As shown, the HGA 36 of this embodiment includes a pair of first microactuators (MA) 65 and a pair of second microactuators (MA) 66. The second MA 66 is an example of a piezoelectric element.

[0055] The first MA65 and the second MA66 are piezoelectric elements. The first MA65 and the second MA66 are, for example, bulk-type piezoelectric elements. Alternatively, the first MA65 and the second MA66 may be bulk-stacked or thin-film piezoelectric elements.

[0056] The pair of first MAs 65 are respectively attached to, for example, portions where the base plate 55 and the load beam 56 are connected. The first MAs 65 are not limited to this example. The pair of first MAs 65 are disposed to be separated from each other in the X direction.

[0057] 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, for example, the load beam 56 is elastically bent in the X direction. Thus, the first MA 65 adjusts the position of the magnetic head 51 .

[0058] The pair of second MAs 66 are attached to, for example, the outer surface 61a of the gimbal portion 61. In the present embodiment, the outer surface 61a is a surface facing the corresponding magnetic disk 12. The magnetic head 51 is also attached to the outer surface 61a. In addition, the outer surface 61a is not limited to this example.

[0059] The pair of second MAs 66 are arranged to be separated from each other in the X direction. The second MAs 66 can expand and contract in the Y direction according to the applied voltage. As the pair of second MAs 66 expand and contract, the gimbal 61 is elastically bent in the X direction. Thus, the second MAs 66 adjust the position of the magnetic head 51.

[0060] As described above, the HDD 10 of this embodiment moves the magnetic head 51 by 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.

[0061] The universal joint portion 61 has two MA mounting portions 71. The two second MAs 66 are mounted on the flexible member 57 at corresponding ones of the two MA mounting portions 71. In addition, the MA mounting portion 71 may be provided at other positions of the flexible member 57.

[0062] Figure 3 FIG. 2 is an illustrative top view showing a portion of the HGA 36 according to the first embodiment. Figure 3As shown, each of the two MA attachment parts 71 includes a peripheral portion 75, a first protruding portion 76, and a second protruding portion 77. The peripheral portion 75 is an example of a base.

[0063] 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 a substantially -Y direction. The -Y direction is an example of the first direction. The second protrusion 77 protrudes from the peripheral portion 75 in a substantially +Y direction at a position away from the first protrusion 76 in the -Y direction. The first protrusion 76 and the second protrusion 77 are separated from each other.

[0064] The first pad 81 is provided on the outer surface 61a of the first protrusion 76. The second pad 82 is provided on the outer surface 61a of the second protrusion 77. That is, the second pad 82 is separated from the first pad 81 in the -Y direction.

[0065] The corresponding end of the second MA66 in the +Y direction is bonded to the first pad 81 by the first adhesive 85. The first adhesive 85 is an example of a first bonded body. The corresponding end of the second MA66 in the -Y direction is bonded to the second pad 82 by the second adhesive 86. The second adhesive 86 is an example of a second bonded body.

[0066] 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 resin 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. In addition, 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.

[0067] The distance between the first protrusion 76 and the second protrusion 77 changes as the second MA 66 expands and contracts in the Y direction. For example, the distance between the first protrusion 76 and the second protrusion 77 in one MA mounting portion 71 is shortened, and the distance between the first protrusion 76 and the second protrusion 77 in the other MA mounting portion 71 is extended, thereby causing the universal joint portion 61 to bend elastically.

[0068] Figure 4 A portion of the HGA 36 of the first embodiment is connected along Figure 3 An exemplary cross-sectional view is shown along line F4-F4. Figure 5 A portion of the HGA 36 of the first embodiment is connected along Figure 3 An exemplary cross-sectional view is shown along line F5-F5.

[0069] like Figure 4As shown, the second MA 66 includes a first piezoelectric body 91, a second piezoelectric body 92, a ground terminal 93, and a signal terminal 94. In addition, the number of piezoelectric bodies included in the second MA 66 is not limited to two.

[0070] 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 as each other and are stacked in the Z direction.

[0071] The first piezoelectric body 91 has a lower surface 91a, an upper surface 91b, and two end surfaces 91c and 91d. The lower surface 91a is an example of the first surface. The upper surface 91b is an example of the second surface. The lower surface 91a, the upper surface 91b, and the end surfaces 91c and 91d are each formed to be substantially flat. The lower surface 91a faces the substantially -Z direction. The upper surface 91b is located on the opposite side of the lower surface 91a and faces the substantially +Z direction. The end surface 91c faces the substantially +Y direction. The end surface 91d is located on the opposite side of the end surface 91c and faces the substantially -Y direction.

[0072] The lower surface 91a faces the outer surface 61a of the universal joint portion 61. In the present embodiment, the lower surface 91a faces the first pad 81 of the first protrusion 76 and the second pad 82 of the second protrusion 77.

[0073] The second piezoelectric body 92 has a lower surface 92a, an upper surface 92b, and two end surfaces 92c and 92d. The lower surface 92a is an example of the third surface. The upper surface 92b is an example of the fourth surface. The lower surface 92a, the upper surface 92b, and the end surfaces 92c and 92d are each formed to be substantially flat. The lower surface 92a faces the substantially -Z direction. The lower surface 92a is mounted on the upper surface 91b of the first piezoelectric body 91. The upper surface 92b is located on the opposite side of the lower surface 92a and faces the substantially +Z direction. The end surface 92c faces the substantially +Y direction. The end surface 92d is located on the opposite side of the end surface 92c and faces the substantially -Y direction.

[0074] The ground terminal 93 and the signal terminal 94 are made of a conductor such as copper. The ground terminal 93 and the signal terminal 94 are separated from each other and attached to the first piezoelectric body 91 and the second piezoelectric body 92 .

[0075] The ground terminal 93 includes a lower film 101, an upper film 102, and a side film 103. 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.

[0076] The lower film 101 is provided on the lower surface 91a of the first piezoelectric body 91. The lower film 101 is separated from the end of the lower surface 91a in the -Y direction 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 separated from the end of the upper surface 92b in the -Y direction in the +Y direction. In the Y direction, the upper film 102 is longer than the lower film 101.

[0077] The side films 103 are provided on the end surface 91c of the first piezoelectric body 91 and the end surface 92c of the second piezoelectric body 92. The side films 103 connect the lower film 101 and the upper film 102. Therefore, the lower film 101, the upper film 102 and the side films 103 can be at the same potential.

[0078] The signal terminal 94 includes a lower film 105, a middle film 106, and a side film 107. The signal terminal 94 is not limited to this example. The lower film 105 is an example of a second electrode. The middle film 106 is an example of a third electrode.

[0079] The lower film 105 is provided on the lower surface 91a of the first piezoelectric body 91. The lower film 105 is away 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. In addition, the middle film 106 can also 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.

[0080] The side films 107 are provided on the end surface 91d of the first piezoelectric body 91 and the end surface 92d of the second piezoelectric body 92. The side films 107 connect the lower film 105 and the middle film 106 to each other. Therefore, the lower film 105, the middle film 106 and the side films 107 can be at the same potential.

[0081] The upper film 102 of the ground terminal 93 overlaps with 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 with 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.

[0082] like Figure 5As shown, the second MA66 has two side surfaces 66a and 66b. The side surface 66a is an example of an end surface. The side surface 66a is provided at the end of the second MA66 in the +X direction. The +X direction is a direction along the lower surface 91a and orthogonal to the -Y direction, and is an example of a third direction. The side surface 66a is formed to be approximately flat and faces approximately 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 the end of the second MA66 in the -X direction. The side surface 66b is formed to be approximately flat and faces approximately in the -X direction.

[0083] The ground terminal 93 and the signal terminal 94 are provided from the side surface 66a of one side to the side surface 66b of the other side 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 side surfaces 66a and 66b. In addition, the portions of the ground terminal 93 and the signal terminal 94 exposed at the side surfaces 66a and 66b may be covered by elements such as the first adhesive 85 and the second adhesive 86 which are not included in the second MA 66.

[0084] like Figure 4 As shown in FIG. 1 , the outer surface 61a of the first protrusion 76 faces the lower film 101 of the ground terminal 93. In the present embodiment, the first protrusion 76 is separated 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 to the ground terminal 93.

[0085] The outer surface 61a of the second protrusion 77 faces the lower film 105 of the signal terminal 94. In the present embodiment, the second protrusion 77 is separated 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 connects the second pad 82 and the signal terminal 94 physically and electrically.

[0086] like Figure 5 As shown, the first adhesive 85 and the second adhesive 86 may be further attached to the side surfaces 66a and 66b of the second MA 66. The first adhesive 85 is separated from the second pad 82, the second adhesive 86, and the signal terminal 94. The second adhesive 86 is separated from the first pad 81, the first adhesive 85, and the ground terminal 93.

[0087] like Figure 4As shown, the flexible member 57 includes 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.

[0088] The backing layer 111, the base layer 112, the conductive layer 113, and the cover layer 114 are stacked in the Z direction at almost all parts of the flexible member 57. Therefore, each of the first protrusion 76 and the second protrusion 77 partially has the backing layer 111, the base layer 112, the conductive layer 113, and the cover layer 114. In addition, the flexible member 57 may have 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, for example.

[0089] 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 substantially flat and faces the +Z direction. The surface 111b is located on the opposite side of the surface 111a. The surface 111b is formed to be substantially flat and faces the -Z direction. The surface 111b is exposed to the outside and forms the surface on the opposite side of the outer surface 61a in the flexible member 57.

[0090] 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 that of the cover layer 114. Alternatively, the material of the base layer 112 and that of the cover layer 114 may be different from each other.

[0091] 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 bonded to the surface 111a via an adhesive layer or may be directly attached to the surface 111a.

[0092] 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 of 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.

[0093] 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. The thickness of the backing layer 111 and the conductive layer 113 is not limited to this example.

[0094] Conductive layer 113, for example, has a plurality of wiring patterns and pads. Conductive layer 113 has a first pad 81 and a second pad 82. Furthermore, conductive layer 113 also has a pad connected to magnetic head 51, a pad connected to FPC 37, and a wiring pattern that connects a plurality of pads to each other. In addition, conductive layer 113 is not limited to this example.

[0095] The covering 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 covering 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 covering layer 114 may be bonded to the surface 112a via an adhesive layer, for example, or may be directly attached to the surface 112a.

[0096] In the flexible member 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. In addition, the flexible member 57 may be a multilayer substrate having a plurality of insulating layers and a plurality of conductive layers instead of the base layer 112.

[0097] 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 flexible member 57. The surface 114b is located on the opposite side of the surface 114a. The surface 114b is fixed to the surface 112a of the base layer 112 and the conductive layer 113.

[0098] The first exposure hole 115 and the second exposure hole 116 are provided in the cover layer 114. The first exposure hole 115 and the second exposure hole 116 penetrate the cover layer 114 substantially in the Z direction and open at the surfaces 114a and 114b.

[0099] The first exposure hole 115 is provided in the first protrusion 76 to expose at least a portion of the first gasket 81 to the outside of the flexible member 57. The surface of the first gasket 81 exposed through the first exposure hole 115 forms a portion of the outer surface 61a of the flexible member 57.

[0100] The second exposure hole 116 is provided in the second protrusion 77 so that at least a portion of the second pad 82 is exposed to the outside of the flexible member 57. The surface of the second pad 82 exposed through the second exposure hole 116 forms a portion of the outer surface 61a of the flexible member 57. That is, the outer surface 61a includes the surface 114a of the cover layer 114, the surface of the first pad 81 exposed through the first exposure hole 115, and the surface of the second pad 82 exposed through the second exposure hole 116.

[0101] A plurality of through holes 121 and 122 are provided in the first protruding portion 76. The plurality of through holes 121 is an example of a first through hole. The plurality of through holes 122 is an example of a first hole. The plurality of through holes 121 and 122 each penetrate the flexible member 57 in the first protruding portion 76 substantially in the Z direction and open in the first pad 81. In the present embodiment, the through holes 121 and 122 penetrate the base layer 112 and the first pad 81 of the conductive layer 113.

[0102] The plurality of through holes 121 are arranged at positions where the upper and lower films 101 and the middle film 106 overlap with the first pad 81 in the -Z direction. In addition, the plurality of through holes 121 of this embodiment are arranged between the end of the first pad 81 and the center of the first pad 81 in the -Y direction.

[0103] The plurality of through holes 122 are arranged at positions away from the middle film 106 in the +Y direction along the outer surface 61a. In other words, the middle film 106 does not overlap with the through holes 122 in the -Z direction. The +Y direction is an example of the fourth direction.

[0104] Each of the plurality of through holes 121 and 122 is formed, for example, in a substantially oval shape extending substantially in the X direction. The plurality of through holes 121 and 122 are arranged at intervals substantially in the Y direction. The plurality of through holes 121 and 122 may also be in other shapes such as a circle, a quadrilateral or a rectangle.

[0105] The cross-sectional area of ​​the through hole 121 is larger than the cross-sectional area of ​​the through hole 122. The cross-sectional area of ​​the through holes 121, 122 is the area of ​​the cross section of the through holes 121, 122 perpendicular to the direction (Z direction) in which the through holes 121, 122 extend.

[0106] In this embodiment, the cross-sectional area of ​​each of the plurality of through holes 121 is larger than the cross-sectional area of ​​each of the plurality of through holes 122. Furthermore, the total cross-sectional area of ​​the plurality of through holes 121 is larger than the total cross-sectional area of ​​the plurality of through holes 122. In addition, 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 also be equal to or smaller than the cross-sectional area of ​​the through hole 122.

[0107] In the first protrusion 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 plurality of through holes 121 and 122 .

[0108] The edge 123a of the through hole 123 is separated from the edge 121a of each of the plurality of through holes 121, and surrounds the plurality of through holes 121. The edge 123a of the through hole 123 is separated from the edge 111c of the backing layer 111. That is, the through hole 123 is formed (defined, partitioned) by the annular (endless) edge 123a.

[0109] The second protrusion 77 is provided with a plurality of through holes 125 and 126. The plurality of through holes 125 is an example of a second through hole. The plurality of through holes 126 is an example of a second hole. The plurality of through holes 125 and 126 each penetrate the flexible member 57 in the second protrusion 77 in a substantially Z direction and open at the second pad 82. In the present embodiment, the through holes 125 and 126 penetrate the base layer 112 and the second pad 82 of the conductive layer 113.

[0110] The plurality of through holes 125 are arranged at positions where the lower film 105 and the upper film 102 overlap with the second pad 82 in the -Z direction. In addition, the plurality of through holes 125 of the present embodiment are arranged between the end of the second pad 82 in the +Y direction and the center of the second pad 82. The plurality of through holes 126 are arranged at positions away from the upper film 102 in the -Y direction along the outer surface 61a.

[0111] Each of the plurality of through holes 125 and 126 is formed, for example, in a substantially oval shape extending substantially in the X direction. The plurality of through holes 125 and 126 are arranged at intervals substantially in the Y direction. The plurality of through holes 125 and 126 may also be in other shapes such as a circle, a quadrilateral or a rectangle.

[0112] The cross-sectional area of ​​the through holes 125 and 126 is smaller than the cross-sectional area of ​​the through hole 121. In the present embodiment, the cross-sectional area of ​​each of the plurality of through holes 125 and 126 is smaller than the cross-sectional area of ​​each of the plurality of through holes 121. Furthermore, the total cross-sectional area of ​​the plurality of through holes 125 is smaller than the total cross-sectional area of ​​the plurality of through holes 121. In addition, the cross-sectional area of ​​the through holes 125 and 126 is not limited to this example. The cross-sectional area of ​​the through holes 125 and 126 may be equal to or larger than the cross-sectional area of ​​the through hole 121.

[0113] In the second protrusion 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 plurality of through holes 125 and 126. The edge 127a of the through hole 127 is separated from the edge 125a of each of the plurality of through holes 125, and surrounds the plurality of through holes 125. The edge 127a of the through hole 127 is separated from the edge 111c of the backing layer 111.

[0114] The first adhesive 85 is partially contained in the through holes 121 and 122. In addition, the first adhesive 85 only needs to slightly enter the through hole 121. A part of the first adhesive 85 is attached to the flexible member 57 at a position where the backing layer 111 overlaps in the +Z direction. That is, a part of the first adhesive 85 is attached to a portion of the flexible member 57 where the backing layer 111 is provided and the rigidity is high. The +Z direction is the direction in which the outer surface 61a faces, and is an example of the sixth direction.

[0115] The second adhesive 86 is partially accommodated in the through holes 125 and 126. The second adhesive 86 only needs to slightly enter the through hole 125. A portion of the second adhesive 86 is attached to the flexible member 57 at a position where the backing layer 111 overlaps in the +Z direction.

[0116] In this embodiment, the first adhesive 85 stays in the through holes 121 and 122 and is away from the through hole 123. In addition, the second adhesive 86 stays in the through holes 125 and 126 and is away from the through hole 127. In addition, the first adhesive 85 and the second adhesive 86 may be partially contained in the through holes 123 and 127.

[0117] 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.

[0118] The second pad 82 is electrically connected to the controller of the PCB 17 via the flexible member 57 and the FPC 37 . The controller applies an electrical signal to the second pad 82 in order to adjust the position of the magnetic head 51 .

[0119] 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. According to the potential difference, the first piezoelectric body 91 and the second piezoelectric body 92 are deformed, thereby the second MA66 expands and contracts in the Y direction. In other words, the second MA66 is extended or contracted in the Y direction (+Y direction and -Y direction) by applying a voltage through the lower film 105.

[0120] An example of a method for mounting the second MA 66 on the flexure 57 will be described below as a part of the method for manufacturing the HDD 10. The method for mounting the second MA 66 is not limited to the following method, and other methods may be used.

[0121] First, the first adhesive 85 is applied to the first gasket 81, and the second adhesive 86 is applied to the second gasket 82. At this time, the first adhesive 85 and the second adhesive 86 are not cured but have fluidity. In addition, the first adhesive 85 can also be applied to the lower film 101 of the ground terminal 93. In addition, the second adhesive 86 can also be applied to the lower film 105 of the signal terminal 94.

[0122] Next, the second MA 66 is placed on the flexible member 57 by, for example, a placement machine. The placement machine brings the second MA 66 close to the flexible member 57 until the distance between the second MA 66 and the flexible member 57 reaches a predetermined value.

[0123] As the second MA 66 approaches the flexible member 57, the first adhesive 85 is compressed between the first gasket 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 flexible member 57. Thus, the first adhesive 85 adheres to the side film 103 of the ground terminal 93. In addition, the first adhesive 85 may also adhere to the side surfaces 66a and 66b of the second MA 66.

[0124] A portion of the first adhesive 85 flows into the plurality of through holes 121, 122. In other words, a portion of the first adhesive 85 is pressed into the through holes 121, 122 by the second MA 66. Due to the resistance in the plurality of 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 diffuses along the second MA 66 and the flexible member 57. In addition, the flow of the first adhesive 85 is not limited to this example.

[0125] The through holes 121 and 122 receive a portion of the first adhesive 85, thereby reducing the amount of the first adhesive 85 that spreads along the second MA 66 and the flexible member 57. Therefore, the through holes 121 and 122 prevent the first adhesive 85 that moves along the side surfaces 66a and 66b of the second MA 66 from reaching the middle film 106 of the signal terminal 94 exposed on the side surfaces 66a and 66b.

[0126] Similarly, as the second MA 66 approaches the flexible member 57, the second adhesive 86 is compressed 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 flexible member 57. Thus, the second adhesive 86 adheres to the side film 107 of the signal terminal 94. In addition, the second adhesive 86 may also adhere to the side surfaces 66a and 66b of the second MA 66.

[0127] A portion of the second adhesive 86 flows into the plurality of through holes 125 and 126. Due to the resistance in the plurality of through holes 125 and 126, the amount of the second adhesive 86 flowing into the through holes 125 and 126 is smaller than the amount diffused along the second MA 66 and the flexible member 57. The flow of the second adhesive 86 is not limited to this example.

[0128] The through holes 125 and 126 receive a portion of the second adhesive 86, thereby reducing the amount of the second adhesive 86 that spreads along the second MA 66 and the flexible member 57. Therefore, the through holes 125 and 126 prevent the second adhesive 86 that moves along the side surfaces 66a and 66b of the second MA 66 from reaching the upper film 102 of the ground terminal 93 exposed on the side surfaces 66a and 66b.

[0129] Next, the first adhesive 85 and the second adhesive 86 are cured. Furthermore, the flexible member 57 is cleaned with, for example, a cleaning liquid to remove, for example, particles generated from the first adhesive 85 and the second adhesive 86. Thus, the mounting of the second MA 66 on the flexible member 57 is completed.

[0130] The through holes 121 , 122 , 123 , 125 , 126 , and 127 may be formed by various methods. For example, the through holes 121 , 122 , 123 , 125 , 126 , and 127 may be formed by etching the backing layer 111 , the base layer 112 , and the conductive layer 113 when manufacturing the flexible member 57 .

[0131] In the HDD 10 involved in the first embodiment described above, the second MA 66 includes 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 the lower surface 91a of the first piezoelectric body 91. The lower film 105 is provided on the lower surface 91a at a position away from the lower film 101 in the -Y direction along the lower surface 91a. The middle film 106 is provided on the upper surface 91b of the first piezoelectric body 91 located on the opposite side of the lower surface 91a and connected to the lower film 105. The flexible member 57 includes 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 away from the first pad 81 in the -Y direction. A through hole 121 is provided in the flexible member 57. The through hole 121 opens at the first pad 81 at a position where the upper and lower films 101 and the middle film 106 overlap in the -Z direction toward which the lower surface 91a is directed. According to another description, the through hole 121 opens at the first pad 81 between the end of the first pad 81 in the -Y direction and the center of the first pad 81. The conductive first adhesive 85 joins the first pad 81 to the lower film 101 and is partially accommodated in the through hole 121.

[0132] The middle film 106 is connected to the lower film 105. Therefore, the middle film 106 is generally away from the end of the upper surface 91b in the opposite direction of the +Y direction in the -Y direction. When the second MA66 is bonded to the first pad 81 through the first adhesive 85, for example, the first adhesive 85 pre-applied to the first pad 81 or the lower film 101 is flattened between the first pad 81 and the lower film 101. At this time, the first adhesive 85 partially flows into the through hole 121, thereby preventing the first adhesive 85 from diffusing along the second MA66 and reaching the middle film 106. Therefore, the HDD10 of this embodiment can prevent the first adhesive 85 from causing a short circuit between the lower film 101 and the middle film 106, and further prevent the reduction in the electrical properties of the second MA66 caused by the short circuit. The HDD10 can be easily manufactured by easily preventing short circuits during manufacturing, and the yield rate can be improved. In addition, the first adhesive 85 is partially accommodated in the through hole 121, and the first gasket 81 is bonded to the lower film 101. That is, the through hole 121 increases the contact area between the flexible member 57 and the first adhesive 85. Therefore, the first adhesive 85 can firmly attach the second MA 66 to the flexible member 57 compared to the case where the first adhesive 85 is simply attached to the surface of the first gasket 81. Therefore, the HDD 10 of the present embodiment can suppress the reduction in strength of the suspension 52 including the second MA 66 and the flexible member 57 even if the through hole 121 is provided in the flexible member 57.

[0133] The second MA66 has a side surface 66a. The side surface 66a is provided at the end of the second MA66 in the +X direction which is perpendicular to the -Y direction and which is along the lower surface 91a. The middle film 106 is exposed to the outside of the second MA66 at least on the side surface 66a. When the first adhesive 85 diffuses along the side surface 66a and reaches the exposed middle film 106, it is possible that the lower film 101 and the middle film 106 are short-circuited. However, the HDD 10 of the present embodiment can prevent the first adhesive 85 from short-circuiting the lower film 101 and the middle film 106 because the first adhesive 85 partially flows into the through hole 121.

[0134] The through hole 122 is provided in the flexible member 57. The through hole 122 opens in the first pad 81 at a position away 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 diffusing along the second MA 66 and reaching the middle film 106. Therefore, the HDD 10 of the present embodiment can more reliably prevent the first adhesive 85 from short-circuiting the lower film 101 and the middle film 106.

[0135] The through hole 122 penetrates the flexible member 57. Thus, the first adhesive 85 easily flows into the through hole 122. Therefore, it is possible to suppress the first adhesive 85 from spreading along the second MA 66 and reaching the middle film 106.

[0136] The cross-sectional area of ​​the through hole 121 is larger than the cross-sectional area of ​​the through hole 122. As a result, the amount of the first adhesive 85 flowing into the through hole 122 at a position away from the middle film 106 is reduced. For example, more of the first adhesive 85 is diffused at a position away from the middle film 106, so that more of the first adhesive 85 can be attached to the side film 103. Therefore, the HDD 10 of the present embodiment can suppress the reduction in the contact area between the second MA 66 and the first adhesive 85, and can suppress the reduction in the strength of the suspension 52 including the second MA 66 and the flexible member 57.

[0137] The second MA66 has a second piezoelectric body 92 and an upper film 102. The lower surface 92a of the second piezoelectric body 92 is mounted on the upper surface 91b. The upper film 102 is arranged on the upper surface 92b of the second piezoelectric body 92 located on the opposite side of the lower surface 92a and is connected to the lower film 101. A through hole 125 is provided in the flexible member 57. The through hole 125 is opened in 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 MA66 is bonded to the second pad 82 through the second adhesive 86, the second adhesive 86 is flattened 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 diffusing along the second MA66 and reaching the upper film 102. Therefore, the HDD 10 of this embodiment can prevent the second adhesive 86 from short-circuiting the lower film 105 and the upper film 102. In addition, even if the through hole 125 is provided in the flexure 57, the HDD 10 of this embodiment can prevent the strength of the suspension 52 including the second MA 66 and the flexure 57 from decreasing.

[0138] The through hole 126 is provided in the flexible member 57. The through hole 126 opens in the second pad 82 at a position away 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 and reaching the upper film 102. Therefore, the HDD 10 of the present embodiment can more reliably prevent the second adhesive 86 from short-circuiting the lower film 105 and the upper film 102.

[0139] The cross-sectional area of ​​the through hole 125 is smaller than the cross-sectional area of ​​the through hole 121. As a result, the amount of the second adhesive 86 flowing into the through hole 125 is reduced. Therefore, the HDD 10 of the present 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 flexible member 57. In addition, 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, in the HDD 10 of the present embodiment, even if the amount of the second adhesive 86 flowing into the through hole 125 is small, it is possible to suppress the second adhesive 86 from causing the lower film 105 and the upper film 102 to short-circuit.

[0140] The flexible member 57 includes 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 includes a first pad 81. A through hole 121 penetrates the base layer 112 and the first pad 81. A through hole 123 communicating with the through hole 121 is provided in the backing layer 111. 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. Thus, even if the first adhesive 85 passes through the through hole 121, it can be prevented from contacting the backing layer 111. That is, the HDD 10 of the present embodiment can prevent the first adhesive 85 from short-circuiting the lower film 101 and the backing layer 111.

[0141] A portion of the first adhesive 85 is attached to the flexible member 57 at a position where the backing layer 111 overlaps in the +Z direction toward the outer surface 61a. That is, the first adhesive 85 joins the portion of the flexible member 57 whose rigidity is increased by the backing layer 111 to the second MA 66. Therefore, the force generated by the second MA 66 is more effectively transmitted to the flexible member 57. Therefore, the HDD 10 of the present embodiment can stably deform the flexible member 57 through the second MA 66, and can further stably adjust the position of the magnetic head 51.

[0142] 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 is attached to the backing layer 111 through the through hole 121, for example, it is possible to suppress the influence on the operation of the first piezoelectric body 91 and the second piezoelectric body 92.

[0143] (Second embodiment)

[0144] Below, refer to Figure 6, the second embodiment is described. In addition, in the description of the following multiple embodiments, for the constituent elements having the same functions as the constituent elements already described, sometimes the same reference numerals as the constituent elements already described are marked, and the description is omitted. In addition, the multiple constituent elements marked with the same reference numerals are not limited to all functions and properties being common, and may also have different functions and properties corresponding to each embodiment.

[0145] Figure 6 2 is an exemplary cross-sectional view showing a portion of the HGA 36 according to the second embodiment. Figure 6 As shown, in the first protrusion 76 of the second embodiment, a plurality of holes 201 are provided instead of the plurality of through holes 122. The holes 201 are an example of the first holes. The holes 201 are substantially the same as the through holes 122 except for the following aspects.

[0146] In the second embodiment, the second protrusion 77 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 the same as the through holes 126 except for the following aspects.

[0147] The plurality of holes 201 penetrate the first pad 81 of the conductive layer 113. The plurality of 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 plurality of holes 201 and 205. Therefore, the hole 201 is a concave portion opened in the first pad 81, and the hole 205 is a concave portion opened in the second pad 82.

[0148] In the HDD 10 of the second embodiment described above, the hole 201 penetrates the first gasket 81. The base layer 112 blocks the hole 201. That is, the hole 201 is shallower than the through hole 121. As a result, the amount of the first adhesive 85 flowing into the hole 201 at a position away from the middle film 106 is reduced. Therefore, the HDD 10 of this embodiment can suppress the reduction of the contact area between the second MA 66 and the first adhesive 85, and can suppress the reduction of the strength of the suspension 52 including the second MA 66 and the flexible member 57.

[0149] (Third embodiment)

[0150] Below, refer to Figure 7 as well as Figure 8 , the third embodiment is described. Figure 7 It is an illustrative plan view showing a part of the HGA 36 according to the third embodiment. Figure 8 A portion of the HGA 36 of the third embodiment is connected along Figure 7 An exemplary cross-sectional view is shown along line F8-F8.

[0151] like Figure 7 As shown, the two MA mounting parts 71 in the third embodiment each have 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 the same as the first protrusion 76 and the second protrusion 77 except for the following aspects. The first protrusion 301 is an example of a protrusion.

[0152] The first protrusion 301 protrudes from the peripheral portion 75 in the −Y direction and is provided with the first spacer 81. The second protrusion 302 protrudes from the peripheral portion 75 in the +Y direction and is provided with the second spacer 82.

[0153] In the X direction, the width of the first protrusion 301 is smaller than the width of the second MA66. In the X direction, the width of the second protrusion 302 is smaller than the width of the second MA66. The X direction is a direction along the lower surface 91a and perpendicular to the -Y direction, and is an example of the fifth direction.

[0154] like Figure 8 As shown, 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. The edge 111c of the backing layer 111 is separated from the 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.

[0155] When the second MA 66 is placed on the flexible member 57, the squashed first adhesive 85 spreads along the second MA 66 and the outer surface 61a of the flexible member 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.

[0156] The second MA66 is exposed without being covered by the first protrusion 301 between the end of the first protrusion 301 in the X direction and the side surfaces 66a and 66b of the second MA66. Therefore, the flow rate of the first adhesive 85 that is flattened and spread is reduced, and the first adhesive 85 is difficult to reach the side surfaces 66a and 66b of the second MA66.

[0157] A portion of the first adhesive 85 spreads along the first protrusion 301 in the X direction. For example, the first adhesive 85 spreads to the edge 112c of the base layer 112. However, since the edge 112c of the base layer 112 is away from the edge 111c of the backing layer 111, it is difficult for the first adhesive 85 to reach the backing layer 111.

[0158] In the HDD 10 of the third embodiment described above, the flexible member 57 has a peripheral portion 75 and a first protrusion 301 protruding from the peripheral portion 75 in the -Y direction and provided with a first pad 81. In the X direction along the lower surface 91a and orthogonal to the -Y direction, the width of the first protrusion 301 is smaller than the width of the second MA 66. When the second MA 66 is bonded to the first pad 81 through 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 protrusion 301 and reaches the end of the first protrusion 301. Except for the end of the first protrusion 301, the lower surface 91a of the second MA 66 is not covered by the first protrusion 301. Therefore, the spread of the crushed first adhesive 85 is reduced after reaching the end of the first protrusion 301. That is, it is possible to suppress the first adhesive 85 from spreading along the second MA 66 and reaching the middle film 106 . Therefore, the HDD 10 of the present embodiment can suppress the first adhesive 85 from short-circuiting the lower film 101 and the middle film 106 .

[0159] In the X direction, the width of the backing layer 111 is smaller than the width of the base layer 112. Therefore, even if the flattened first adhesive 85 reaches the edge 112c of the base layer 112, it still leaves the backing layer 111. Therefore, the HDD 10 of this embodiment can prevent the first adhesive 85 from short-circuiting the lower film 101 and the backing layer 111.

[0160] In the above embodiment, the second MA 66 is mainly described. However, the pad for mounting the first MA 65 may be provided with at least one of the through holes 121, 122, 123, 125, 126, 127 and the holes 201, 205, similarly to the first pad 81 and the second pad 82. In addition, the through holes 122, 125, 126, 127 and the holes 201, 205 may be omitted.

[0161] Several embodiments of the present invention have been described, but 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 changes can be made without departing from the gist of the invention. These embodiments and their variations are included in the scope and gist of the invention, and are included in the invention described in the claims and the scope of their equivalents.

Claims

1. A disk device comprising: disk; a magnetic head configured to read and write information to the magnetic disk; A piezoelectric element comprising a first piezoelectric body, a first electrode disposed on a first surface of the first piezoelectric body, a second electrode disposed on the first surface at a position away from the first electrode in a first direction along the first surface, and a third electrode disposed on a second surface of the first piezoelectric body located on the opposite side of the first surface and connected to the second electrode; A flexible member having an outer surface facing the first electrode and the second electrode, a first pad disposed on the outer surface, and a second pad disposed on the outer surface at a position away from the first pad in the first direction, wherein the flexible member is provided with a first through hole, the first through hole is opened at the first pad at a position where the first electrode and the third electrode overlap in the second direction facing the first surface, and the magnetic head is mounted on the flexible member; a conductive first bonding body that bonds the first pad to the first electrode and is partially accommodated in the first through hole; and A conductive second bonding body bonds the second pad and the second electrode.

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

3. The disk device according to claim 1, The flexible member is provided with a first hole, The first hole opens at the first pad at a position away from the third electrode in a fourth direction opposite to the first direction along the outer surface.

4. The disk device according to claim 3, The first hole passes through the flexible member.

5. The disk device according to claim 3, The flexible member comprises 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 penetrates the first gasket, The second insulating layer blocks the first hole.

6. The disk device according to claim 3, A cross-sectional area of ​​the first through hole is larger than a cross-sectional area of ​​the first hole.

7. The disk device according to claim 1, The piezoelectric element has a second piezoelectric body and a fourth electrode. The third surface of the second piezoelectric body is mounted on the second surface, The fourth electrode is provided on a fourth surface of the second piezoelectric body located on the opposite side of the third surface and is connected to the first electrode. The flexible member is provided with a second through hole, the second through hole opening at 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.

8. The disk device according to claim 7, The flexible member is provided with a second hole, The second hole opens in the second pad at a position away from the fourth electrode along the outer surface in the first direction.

9. The disk device according to claim 7, A cross-sectional area of ​​the second through hole is smaller than a cross-sectional area of ​​the first through hole.

10. The disk device according to claim 1, The flexible member has a base portion and a protrusion portion protruding from the base portion toward the first direction and provided with the first pad. In a fifth direction that is along the first surface and perpendicular to the first direction, a width of the protrusion is smaller than a width of the piezoelectric element.

11. The disk device according to claim 10, The protrusion 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.

12. The disk device according to claim 1, The flexible member comprises 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. The metal plate is provided with a third through hole communicating with the first through hole, The edge of the third through hole is separated from the edge of the first through hole and surrounds the first through hole.

13. The disk device according to claim 1, The flexible member comprises 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 flexible member at a position where the metal plate overlaps with the metal plate in the sixth direction in which the outer surface faces.

14. The disk device according to claim 1, The first pad is set to a ground potential, The piezoelectric element is configured to expand or contract in the first direction when a voltage is applied to the second electrode.

15. A disk device comprising: disk; a magnetic head configured to read and write information to the magnetic disk; A piezoelectric element comprising a first piezoelectric body, a first electrode disposed on a first surface of the first piezoelectric body, a second electrode disposed on the first surface at a position away from the first electrode in a first direction along the first surface, and a third electrode disposed on a second surface of the first piezoelectric body located on the opposite side of the first surface and connected to the second electrode; A flexible member having an outer surface facing the first electrode and the second electrode, a first pad disposed on the outer surface, and a second pad disposed on the outer surface at a position away from the first pad in the first direction, wherein a first through hole opened in the first pad is disposed between an end of the first pad in the first direction and a center of the first pad, and the magnetic head is mounted on the flexible member; a conductive first bonding body that bonds the first pad to the first electrode and is partially accommodated in the first through hole; and A conductive second bonding body bonds the second pad and the second electrode.

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