disc device

Abstract

Embodiments of the present invention relate to a disk device that improves the reliability of flexible printed circuit boards. One embodiment of the disk device includes a magnetic disk, a magnetic head, a flexible printed circuit board, and electronic components. The flexible printed circuit board has a first insulating layer, a first conductive layer disposed on a first surface of the first insulating layer, a second conductive layer disposed on a second surface of the first insulating layer, a second insulating layer covering the second surface and the second conductive layer, and a first adhesive layer for bonding the second insulating layer to the second surface and the second conductive layer. The first conductive layer has a first connecting pad. A plurality of first through holes are provided in the second conductive layer at a first portion overlapping the first insulating layer and the first connecting pad. The first adhesive layer is attached to the second surface through the plurality of first through holes. The electronic components have first pins that engage with the first connecting pad.

Description

[0001] Reference to related applications: This application enjoys priority to Japanese Patent Application No. 2024-227324 (filed on December 24, 2024). This application incorporates the entire contents of the basic application by reference to that basic application. Technical Field

[0002] Embodiments of the present invention relate to a disk device. Background Technology

[0003] Disk devices such as hard disk drives have flexible printed circuit boards (FPCs) and electronic components mounted on the FPCs. For example, the pins of the electronic components are bonded to pads provided on the FPCs.

[0004] For example, when electronic components generate a rotational (torsional) torque on the surface of an FPC, a force acts on the FPC near the bonding pads along the direction of that surface. This force acts on the adhesive portion between the insulating and conductive layers of the FPC, potentially reducing the reliability of the FPC. Summary of the Invention

[0005] The problem to be solved by the present invention is to provide a disk device that can improve the reliability of flexible printed circuit boards.

[0006] One embodiment of the disk device includes a magnetic disk, a read / write head, a flexible printed circuit board (FPCB), and electronic components. The read / write head is configured to read and write information relative to the magnetic disk. The FPCB is electrically connected to the read / write head. The electronic components are mounted on the FPCB. The FPCB has: a first insulating layer; a first conductive layer disposed on a first surface of the first insulating layer; a second conductive layer disposed on a second surface of the first insulating layer located opposite to the first surface; a second insulating layer covering the second surface and the second conductive layer; and a first adhesive layer bonding the second insulating layer to the second surface and the second conductive layer. The first conductive layer has a first connecting pad. A plurality of first through holes are provided in a first portion of the second conductive layer that overlaps with the first connecting pad through the first insulating layer. The first adhesive layer is attached to the second surface through the plurality of first through holes. The electronic components have first pins that engage with the first connecting pad. Attached Figure Description

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

[0008] Figure 2 This is a schematic plan view illustrating an example of the FPC of the first embodiment.

[0009] Figure 3 This is an illustrative cross-sectional view schematically representing a portion of the HDD of the first embodiment.

[0010] Figure 4 This is an illustrative plan view schematically showing the second connection portion of the FPC in the first embodiment.

[0011] Figure 5 It is along Figure 4 The F5-F5 line schematically represents an exemplary cross-sectional view of the second connection portion and the relay connector in the first embodiment.

[0012] Figure 6 This is an illustrative cross-sectional view schematically representing a portion of the HDD of the second embodiment.

[0013] Explanation of symbols

[0014] 10: Hard Disk Drive (HDD); 11: Housing; 12: Disk; 17: Printed Circuit Board (PCB); 37: Flexible Printed Circuit Board (FPC); 48: Magnetic Head; 53, 65: Relay Connector; 66: Relay Device; 71: Housing; 72, 72A, 72B, 72C: Pins; 81: Base Layer; 81a: First Surface; 81b: Second Surface; 82, 83: Conductive Layer; 84, 85: Cover Layer; 86, 87: Adhesive Layer; 91, 91A, 91B, 91C: Pads; 92, 92A, 92B: Wiring; 95: Ground Ground; 100, 100A, 100B, 100C, 200: Mesh Section; 101, 201: Through-Hole; L1: Column; S: Solder. Detailed Implementation

[0015] (First Implementation)

[0016] The following is for reference Figures 1 to 5 The first embodiment will be described. Furthermore, in this specification, the constituent elements of the embodiment and their descriptions are sometimes described in various ways. The constituent elements and their descriptions are merely examples and are not limited to the representations in this specification. Constituent elements may also be identified by names different from those used in this specification. Moreover, constituent elements may also be described in representations different from those used in this specification.

[0017] In the following description, "suppression" is defined, for example, as preventing the occurrence of a phenomenon, effect, or influence, or reducing the degree of a phenomenon, effect, or influence. Similarly, in the following description, "restriction" is defined, for example, as preventing movement or rotation, or allowing movement or rotation within a specified range and preventing movement or rotation beyond that specified range.

[0018] Figure 1 This is an exemplary perspective view showing the hard disk drive (HDD) 10 of the first embodiment in exploded view. HDD 10 is an example of a disk device, and may also be referred to as an electronic device, storage device, external storage device, or disk device. However, the disk device is not limited to HDD 10.

[0019] As shown in the accompanying drawings, for convenience, an X-axis, a Y-axis, and a Z-axis are defined in this specification. The X-axis, Y-axis, and Z-axis are orthogonal to each other. The X-axis is set along the width of the HDD10. The Y-axis is set along the length of the HDD10. The Z-axis is set along the thickness of the HDD10.

[0020] Furthermore, in this specification, the X direction, Y direction, and Z direction are defined. The X direction is the direction along the X-axis, including the +X direction indicated by the arrow on the X-axis and the -X direction, which is the opposite direction of the arrow on the X-axis. The Y direction is the direction along the Y-axis, including the +Y direction indicated by the arrow on the Y-axis and the -Y direction, which is the opposite direction of the arrow on the Y-axis. The Z direction is the direction along the Z-axis, including the +Z direction indicated by the arrow on the Z-axis and the -Z direction, which is the opposite direction of the arrow on the Z-axis.

[0021] like Figure 1 As shown, HDD10 has a housing 11, multiple 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 disks 12 may also be referred to as platters, media, or disks.

[0022] The housing 11 has a base 21, an inner cover 22, and an outer cover 23. However, the housing 11 is not limited to this example. The base 21 is formed as a generally rectangular box shape opening in the +Z direction. The base 21 houses multiple disks 12, a spindle motor 13, an HSA 14, a VCM 15, and a ramp loading mechanism 16.

[0023] The base 21 has a bottom wall 25 and side walls 26. The bottom wall 25 is formed as a generally rectangular (quadrilateral) plate arranged in a manner generally orthogonal to the Z direction. The side walls 26 protrude from the edge of the bottom wall 25 in a generally +Z direction and are formed as a generally rectangular frame.

[0024] The inner cover 22 is mounted to the end of the side wall 26 in the +Z direction, for example, by screws, and blocks the base 21. The outer cover 23 covers the inner cover 22, for example, by welding to the end of the side wall 26 in the +Z direction.

[0025] A vent 27 is provided on the inner cover 22. A vent 28 is provided on the outer cover 23. Components are installed inside the base 21. After the inner cover 22 and outer cover 23 are installed on the base 21, air inside the housing 11 is discharged through the vents 27 and 28. Furthermore, the housing 11 is filled with a gas different from air.

[0026] The gas filling the casing 11 may be a low-density gas with a lower density than air, or a non-reactive gas with low reactivity. For example, helium is filled inside the casing 11. Alternatively, other fluids may be filled inside the casing 11.

[0027] The vent 28 of the outer casing 23 is blocked by the seal 29. The seal 29 airtightly seals the vent 28, preventing fluid filling the interior of the housing 11 from leaking from the vent 28 to the exterior of the housing 11.

[0028] Multiple disks 12 are formed in a disk shape and arranged substantially parallel to the bottom wall 25. The multiple disks 12 are arranged at intervals in the Z direction. A spindle motor 13 supports the multiple disks 12. The multiple disks 12 are held to the hub of the spindle motor 13, for example by clamping springs. The spindle motor 13 rotates the multiple disks 12.

[0029] The housing 11 is provided with a support shaft 31 that is separate from the disk 12. The support shaft 31 extends, for example, from the bottom wall 25 of the housing 11 in the +Z direction. The HSA14 is supported by the support shaft 31 and is able to rotate about the support shaft 31.

[0030] HSA14 has a carriage 35, multiple head gimbal assemblies (HGA) 36, and a flexible printed circuit board (FPC) 37. The carriage 35 has an actuator block 41 and multiple arms 42.

[0031] The actuator block 41 is supported on the support shaft 31 via a bearing, for example, in a manner that allows it to rotate about the support shaft 31. A plurality of arms 42 protrude generally parallel from the actuator block 41.

[0032] Multiple arms 42 are arranged at intervals in the Z direction. Each of the multiple arms 42 can enter the gap between two adjacent disks 12.

[0033] VCM15 has a voice coil mounted on the carriage 35, a pair of yokes, and magnets disposed on the respective yokes. VCM15 causes the carriage 35 to rotate about the support shaft 31.

[0034] Multiple HGA36 units each have a base plate 45, a loading beam 46, a flexible element 47, and a magnetic head 48. The base plate 45 is mounted at the front end of the arm 42. The loading beam 46 is thinner than the base plate 45 and extends from the base plate 45.

[0035] The flexible element 47 is formed in the form of an elongated strip. Furthermore, the shape of the flexible element 47 is not limited to this example. The flexible element 47 is an FPC having a metal plate (lining layer) such as stainless steel, an insulating layer (base layer) formed on the metal plate, a conductive layer formed on the insulating layer and constituting multiple wirings (wiring pattern), and an insulating layer (covering layer) covering the conductive layer.

[0036] A gimbal portion (elastic support portion) located on the loading beam 46 and capable of displacement is provided at one end of the flexible member 47. The magnetic head 48 is mounted on the gimbal portion of the flexible member 47. The magnetic head 48 records and reproduces information relative to the recording layer of the disk 12. In other words, the magnetic head 48 reads and writes information relative to the disk 12.

[0037] VCM15 rotates the carriage 35, thereby positioning the read / write head 48 at the desired position on the disk 12. When the read / write head 48 moves to the outermost periphery of the disk 12, the ramp loading mechanism 16 holds the read / write head 48 in an unloaded position separated from the disk 12.

[0038] The FPC37 is connected to the other end of the flexible element 47. For example, multiple flexible elements 47 are connected to the FPC37. Thus, the FPC37 is electrically connected to multiple magnetic heads 48 via wiring through the multiple flexible elements 47.

[0039] PCB 17 is, for example, a rigid substrate such as a glass epoxy board, and is a multilayer substrate or a laminated substrate. PCB 17 is disposed outside the housing 11 and mounted on the bottom wall 25 of the base 21. PCB 17 is mounted to the bottom wall 25, for example, by a plurality of screws.

[0040] HDD10 also includes, for example, an interface (I / F) connector 51, a controller 52, and a relay connector 53. The relay connector 53 is an example of the first connector. The I / F connector 51, controller 52, and relay connector 53 are mounted on PCB17. Other components may also be mounted on PCB17.

[0041] I / F connector 51 is a connector conforming to an interface standard such as Serial ATA (SATA) and connects to the host computer's I / F connector. Controller 52 is, for example, a system-on-a-chip (SoC) with read / write channels (RWC), a hard disk controller (HDC), and a processor.

[0042] PCB17 is electrically connected to various components disposed inside housing 11 via relay connector 53. For example, PCB17 is electrically connected to spindle motor 13, VCM15, FPC37, flexible component 47, and magnetic head 48.

[0043] Figure 2 This is a schematic plan view illustrating the FPC37 of the first embodiment. (Example) Figure 2 As shown, the FPC37, in its natural state after being disassembled from other parts and without any external force applied, is formed into a roughly L-shaped strip. However, the shape of the FPC37 is not limited to this example. The FPC37 has a first connecting portion 61, a second connecting portion 62, and a middle portion 63.

[0044] The first connecting portion 61 is, for example, provided at one end of the FPC37 in the direction of extension of the FPC37. The first connecting portion 61 is mounted to the actuator block 41, for example, by a screw. The first connecting portion 61 is connected to a plurality of flexible members 47.

[0045] The second connecting part 62 is provided, for example, at the other end of the FPC37 in the direction in which the FPC37 extends. The second connecting part 62 is mounted to the bottom wall 25 of the housing 11, for example, by screws.

[0046] The intermediate portion 63 is disposed between the first connecting portion 61 and the second connecting portion 62. The intermediate portion 63 extends in a strip shape and flexes between the first connecting portion 61 and the second connecting portion 62 in response to the rotation of the actuator block 41.

[0047] Figure 3 This is an illustrative cross-sectional view schematically representing a portion of the HDD10 in the first embodiment. For example... Figure 3 As shown, HSA14 also includes a repeater connector 65, a repeater device 66, and a reinforcing plate 67. The repeater connector 65 is an example of an electronic component and a second connector.

[0048] The repeater connector 65 is mounted on the second connection portion 62 of the FPC 37. Therefore, the repeater connector 65 is housed within the housing 11. The repeater connector 65 is, for example, a compression connector. Alternatively, the repeater connector 65 could be other connectors such as a stacked connector. Furthermore, the electronic component is not limited to the repeater connector 65 and could be other electronic components. The repeater connector 65 has a housing 71 and a plurality of pins 72. The housing is an example of an insulating component.

[0049] The outer casing 71 is made of an insulating material, for example, synthetic resin. The outer casing 71 is formed, for example, into a generally rectangular parallelepiped shape extending along the X direction. The outer casing 71 has a bottom surface 71a, a top surface 71b, and two side surfaces 71c and 71d. Furthermore, the representation of top and bottom in this embodiment is based on... Figure 3 For the sake of convenience, it does not limit the direction, location, or usage.

[0050] The bottom surface 71a is generally flat and faces the +Z direction. The bottom surface 71a faces the second connecting portion 62 of the FPC37. The upper surface 71b is located on the opposite side of the bottom surface 71a and faces the -Z direction. The two side surfaces 71c and 71d are located on opposite sides of each other. Side surface 71c faces the -Y direction. Side surface 71d faces the +Y direction.

[0051] Figure 4 This is an illustrative plan view schematically showing the second connection portion 62 of the FPC37 in the first embodiment. Figure 5 It is along Figure 4 The F5-F5 line schematically represents an exemplary cross-sectional view of the second connection portion 62 and the relay connector 65 in the first embodiment.

[0052] like Figure 5 As shown, multiple pins 72 are held in the housing 71, for example, by means of slots embedded in the housing 71. Figure 4 As shown, multiple pins 72 are arranged to form two columns L1 and L2. The multiple pins 72 forming column L1 are arranged at approximately equal intervals in the X direction. Column L2 separates from column L1 in the +Y direction. The multiple pins 72 forming column L2 are arranged at approximately equal intervals in the X direction.

[0053] like Figure 5 As shown, each of the multiple pins 72 has a connecting portion 75 and a contact portion 76. The connecting portion 75 is disposed at one end of the pin 72. The contact portion 76 is disposed at the other end of the pin 72.

[0054] The joints 75 of the plurality of pins 72 forming column L1 protrude from the side 71c of the housing 71. The joints 75 of the plurality of pins 72 forming column L2 protrude from the side 71d of the housing 71. In addition, the contact portions 76 of the plurality of pins 72 protrude from the upper surface 71b of the housing 71.

[0055] Figure 3 The relay device 66 shown, for example, has a PCB. The relay device 66 is mounted on the bottom wall 25 in a manner that hermetically seals the through hole H provided in the bottom wall 25 of the base 21. Thus, the relay device 66 is disposed in the housing 11.

[0056] The contact portion 76 of pin 72 contacts a pad provided on the surface of the repeater device 66. Thus, the repeater device 66 is electrically connected to the repeater connector 65. Furthermore, the terminals of the repeater connector 53, which is a compression connector, contact the repeater device 66. Thus, the repeater connector 53 is electrically connected to the repeater device 66. Additionally, if the repeater connector 53 is a stacked connector, the repeater device 66 has a stacked connector that connects to the repeater connector 53.

[0057] PCB17 is electrically connected to FPC37 via relay connector 53, relay device 66, and relay connector 65. Thus, controller 52 is electrically connected to magnetic head 48 via PCB17, relay connector 53, relay device 66, relay connector 65, FPC37, and flexible member 47.

[0058] The reinforcing plate 67 is made of, for example, a metal such as aluminum or a synthetic resin, and is formed in a plate shape. However, the reinforcing plate 67 is not limited to this example. The reinforcing plate 67 is mounted on the second connection portion 62 of the FPC37. The second connection portion 62 is located between the relay connector 65 and the reinforcing plate 67.

[0059] The stiffening plate 67 has higher rigidity than the FPC 37. Therefore, the stiffening plate 67 increases the rigidity of the second connection 62. At least a portion of the intermediate portion 63 is not attached to the stiffening plate 67 and is able to flex.

[0060] like Figure 5 As shown, FPC37 has a base layer 81, two conductive layers 82 and 83, two capping layers 84 and 85, and two adhesive layers 86 and 87. Additionally, for ease of explanation, Figure 4 The cover layer 84 and the adhesive layer 86 are omitted.

[0061] The base layer 81 is an example of a first insulating layer. The conductive layer 82 is an example of a first conductive layer. The conductive layer 83 is an example of a second conductive layer. The capping layer 84 is an example of a third insulating layer. The capping layer 85 is an example of a second insulating layer. The adhesive layer 86 is an example of a second adhesive layer. The adhesive layer 87 is an example of a first adhesive layer.

[0062] The base layer 81 and the capping layers 84 and 85 are made of an insulating synthetic resin such as polyimide (PI). Alternatively, the base layer 81 and the capping layers 84 and 85 can also be made of other resins.

[0063] like Figure 5 As shown, the base layer 81 has a first surface 81a and a second surface 81b. The first surface 81a faces approximately in the -Z direction. The first surface 81a faces the relay connector 65. The second surface 81b is located on the opposite side of the first surface 81a and faces approximately in the +Z direction. The second surface 81b faces the reinforcing plate 67.

[0064] Conductive layers 82 and 83 are made of a conductive metal, such as copper. However, the materials of conductive layers 82 and 83 are not limited to this example. Conductive layers 82 and 83 respectively form the wiring pattern of the FPC37.

[0065] A conductive layer 82 is disposed on the first surface 81a of the base layer 81. The conductive layer 82 has a plurality of pads 91 and a plurality of wirings 92. The pads 91 may also be referred to as connection pads, electrodes or terminals, for example.

[0066] Pad 91 is an electrode located on the second connection portion 62. For example... Figure 4 As shown, the plurality of pads 91 are formed, for example, in a generally rectangular shape. Furthermore, the shape of the pads 91 is not limited to this example.

[0067] The conductive layer 82 also has a plurality of other pads disposed on the first connection portion 61 and bonded to the flexible member 47. Multiple wirings 92 respectively connect the plurality of pads 91 disposed on the second connection portion 62 and at least two of the other plurality of pads disposed on the first connection portion 61. Furthermore, the conductive layer 82 may also connect the pads 91 to, for example, other pads bonded to the VCM 15.

[0068] Similar to the multiple pins 72, multiple pads 91 are arranged in two columns L3 and L4. The multiple pads 91 forming column L3 are arranged at approximately equal intervals in the X direction. Column L4 separates from column L3 in the +Y direction. The multiple pads 91 forming column L4 are arranged at approximately equal intervals in the X direction.

[0069] like Figure 5 As shown, multiple pads 91 are electrically and mechanically engaged with the corresponding junction 75 of one of the multiple pins 72 via solder S. Thus, the relay connector 65 is mounted on the second connection portion 62 of the FPC37.

[0070] like Figure 4 As shown, multiple pads 91 include, for example, pads 91A, 91B, and 91C. Additionally, multiple pins 72 include pins 72A, 72B, and 72C. Pad 91A is an example of a first connection pad. Pad 91B is an example of a second connection pad. Pad 91C is an example of a third connection pad. Pin 72A is an example of a first pin. Pin 72B is an example of a second pin. Pin 72C is an example of a third pin.

[0071] Pin 72A is one of a plurality of pins 72 located at the end of column L1. Pad 91A is one of a plurality of pads 91 located at the end of column L3. Pin 72A is bonded to pad 91A by solder S.

[0072] Pin 72B is one of a plurality of pins 72 located in column L1. Pad 91B is one of a plurality of pads 91 located in column L3. Pin 72B is bonded to pad 91B by solder S.

[0073] Pin 72C is one of a plurality of pins 72 located in column L2. Pad 91C is one of a plurality of pads 91 located in column L4. Pin 72C is bonded to pad 91C via solder S.

[0074] Pin 72C and pad 91C are electrically connected to the read / write head 48 via wiring 92 and flexible element 47. Pin 72C and pad 91C transmit read or write signals.

[0075] The read signal is the electrical signal corresponding to the information read by the read / write head 48 from the disk 12. The write signal is the electrical signal corresponding to the information written by the read / write head 48 to the disk 12. That is, the relay connector 65 inputs a read signal from the read / write head 48 to pin 72C, or outputs a write signal from pin 72C to the read / write head 48. Furthermore, electronic components such as amplifiers can also be placed on the electrical path between pin 72C and the read / write head 48.

[0076] Pin 72A and pad 91A may be set to ground potential, for example, or transmit an electrical signal different from the write and read signals. Such an electrical signal could be, for example, the output signal of a contact sensor, the control signal of a laser element in heat-assisted magnetic recording (HAMR), the control signal of an oscillator element in microwave-assisted magnetic recording (MAMR), or the control signal of a heater. Alternatively, pin 72A and pad 91A may also transmit other electrical signals.

[0077] Pin 72B and pad 91B are set to ground potential. A portion of the wiring 92 connected to pad 91B overlaps with the housing 71 of the repeater connector 53 and forms a ground plane. Furthermore, pins 72A, 72B, 72C and pads 91A, 91B, 91C are not limited to the examples above.

[0078] Multiple traces 92 include, for example, multiple traces 92A and multiple traces 92B. Traces 92A are an example of a second trace. Traces 92B are an example of a first trace. Each of the multiple traces 92A is thinner than each of the multiple traces 92B. One of the multiple traces 92A is connected to pad 91A. One of the multiple traces 92B is connected to pad 91B.

[0079] The width of the wiring 92A along the first surface 81a is smaller than the width of the pad 91 along the first surface 81a. The width of the wiring 92B along the first surface 81a is, for example, approximately the same as the width of the pad 91 along the first surface 81a, or locally thicker. The widths of the wirings 92A and 92B are not limited to this example.

[0080] like Figure 5 As shown, the conductive layer 83 is disposed on the second surface 81b of the base layer 81. Figure 4 As shown, the conductive layer 83 has a ground plane 95. The conductive layer 83 may also have other patterns such as wiring.

[0081] Ground plane 95 is set to ground potential, for example. In this embodiment, ground plane 95 is separated from the portion of the base layer 81 that overlaps with the housing 71 of the relay connector 65. That is, ground plane 95 in this embodiment does not overlap with housing 71. Alternatively, ground plane 95 may overlap with housing 71.

[0082] In this embodiment, the conductive layer 83, including the ground plane 95, is separated from the portion of the base layer 81 that overlaps with the pad 91C. Furthermore, the conductive layer 83 is separated not only from the pad 91C, but also from the portion of the base layer 81 that overlaps with the pad 91 for transmitting read or write signals. That is, the conductive layer 83 in this embodiment does not overlap with the pad 91 for transmitting read or write signals. However, the conductive layer 83 is not limited to this example.

[0083] like Figure 5 As shown, capping layer 84 covers the first surface 81a of base layer 81 and the wiring 92 of conductive layer 82. Capping layer 85 covers the second surface 81b of base layer 81 and conductive layer 83. Therefore, base layer 81 and conductive layers 82 and 83 are located between the two capping layers 84 and 85.

[0084] Adhesive layers 86 and 87 are, for example, epoxy-based adhesives. Alternatively, adhesive layers 86 and 87 can also be adhesives made of other resins, such as acrylic adhesives. Adhesive layer 86 bonds the cover layer 84 to the first surface 81a and the wiring 92. Adhesive layer 87 bonds the cover layer 85 to the second surface 81b and the conductive layer 83.

[0085] Multiple through-holes are provided in the cover layer 84 and the adhesive layer 86. These through-holes expose multiple pads 91 to the outside of the FPC 37. Therefore, the bonding portion 75 of the pin 72 can be bonded to the pad 91 by solder S. The cover layer 85 is bonded to the reinforcing plate 67, for example, by adhesive.

[0086] The ground plane 95 of the conductive layer 83 has a plurality of mesh portions 100. Each mesh portion 100 is a part of the ground plane 95 and has been meshed. That is, each mesh portion 100 has a plurality of through holes 101. The plurality of through holes 101 penetrate the ground plane 95 in a generally Z-direction. Figure 4 As shown, the multiple through holes 101 are approximately rhomboid in shape. Alternatively, the through holes 101 can also be other shapes, or they can be different shapes from each other.

[0087] The plurality of mesh portions 100 includes, for example, a plurality of mesh portions 100A, 100B, and 100C. Mesh portion 100A is an example of a first part. Mesh portion 100B is an example of a second and third part. Mesh portion 100C is an example of a second and fourth part.

[0088] The mesh portion 100A is the portion of the ground plane 95 that overlaps with the pad 91A across the base layer 81. That is, the outline of the mesh portion 100A is approximately equal to the outline of the pad 91A. Therefore, the width of the mesh portion 100A along the first surface 81a is greater than the width of the wiring 92A along the first surface 81a. A plurality of through holes 101 are provided in the mesh portion 100A. The plurality of through holes 101 in the mesh portion 100A is an example of a plurality of first through holes.

[0089] The mesh portion 100B is the part of the ground plane 95 that overlaps with the pad 91B across the base layer 81. Therefore, the mesh portion 100B is also a part of the ground plane 95 that is separate from the mesh portion 100A. A plurality of through holes 101 are provided in the mesh portion 100B. The plurality of through holes 101 in the mesh portion 100B is an example of a plurality of second through holes and a plurality of third through holes.

[0090] The plurality of mesh portions 100 includes not only mesh portions 100A and 100B, but also multiple portions of the ground plane 95 that overlap with the pads 91 across the base layer 81. In this embodiment, all pads 91 that overlap with the ground plane 95 across the base layer 81 also overlap with the via 101 across the base layer 81. Furthermore, at least a portion of the ground plane 95 that overlaps with the pads 91 across the base layer 81 may not be a mesh portion 100.

[0091] The mesh portion 100C is the part of the ground plane 95 that overlaps with the wiring 92B across the substrate layer 81. Therefore, the mesh portion 100C is also the part of the ground plane 95 that is separate from the mesh portion 100A. A plurality of through holes 101 are provided in the mesh portion 100C. The plurality of through holes 101 in the mesh portion 100C are an example of a plurality of second through holes and a plurality of fourth through holes.

[0092] like Figure 5 As shown, the adhesive layer 87 is attached to the second surface 81b of the base layer 81 through a plurality of through holes 101. That is, the adhesive layer 87 is attached to the second surface 81b of the base layer 81 through the plurality of through holes 101 of each of the mesh portions 100A, 100B, and 100C. In this case, the adhesive layer 87 is disposed inside each of the plurality of through holes 101 and on the second surface 81b of the base layer 81. In this embodiment, the adhesive layer 87 fills the interior of the plurality of through holes 101.

[0093] The adhesive layer 87 is also attached to the surface 95a of the ground plane 95 and the inner surface 95b of the ground plane 95 that defines the through hole 101. However, the adhesive layer 87, made of a resin such as epoxy resin, is less likely to form a chemical bond with the ground plane 95 made of a metal such as copper compared to the case where it is attached to a resin. Therefore, the adhesive layer 87 is weakly bonded to the surface 95a and the inner surface 95b of the ground plane 95.

[0094] On the other hand, the adhesive layer 87 readily forms a chemical bond with the base layer 81 made of a resin such as PI. Therefore, the adhesive layer 87 can be firmly bonded to the second surface 81b of the base layer 81.

[0095] Furthermore, the adhesive layer 87 is attached to the inner surface 95b of the plurality of through holes 101, thereby providing a larger contact area between the adhesive layer 87 and the ground surface 95. Additionally, the adhesive layer 87 penetrates the plurality of through holes 101, thus creating an anchoring effect. Therefore, the overall adhesive strength between the adhesive layer 87 and the ground surface 95 is improved.

[0096] As described above, the adhesive layer 87 can adhere to the ground surface 95 relatively strongly, and the ground surface 95 is held to the second surface 81b of the base layer 81 through the through hole 101. Therefore, the ground surface 95 is difficult to peel off from the adhesive layer 87, and also difficult to peel off from the second surface 81b of the base layer 81.

[0097] In this embodiment, the plurality of mesh portions 100 in the ground plane 95 are meshed and have a plurality of through holes 101. On the other hand, other parts of the ground plane 95 are not meshed. However, it is also possible to mesh other parts of the ground plane 95, or to mesh the entire area of ​​the ground plane 95.

[0098] When the repeater connector 65 is installed on the FPC 37 or connected to the repeater device 66, installation misalignment may sometimes occur. Due to this installation deviation, circumferential issues may sometimes arise around the repeater connector 65. Figure 4 The torque (torque) at the center C. The center C is, for example, an imaginary axis of rotation extending approximately in the Z direction. That is, sometimes a torque is generated in the repeater connector 65 in the direction along the first surface 81a of the base layer 81. In addition, due to the warping of the FPC 37 and the repeater connector 65, sometimes a torque about the center C is also generated in the repeater connector 65.

[0099] Because the relay connector 65 generates a torque around the center C, a force is exerted on the FPC37 around the center C, for example, from the pins 72 via the solder S. The pins 72 located at the ends of columns L1 and L2 are further away from the center C than the other pins 72. Therefore, a larger force is exerted from, for example, pin 72A among the multiple pins 72, on the vicinity of pad 91A in the FPC37.

[0100] Due to forces surrounding the center C, torsional stress is generated, for example, at the adhesive portion between the second surface 81b of the base layer 81 and the ground surface 95. If the adhesive force between the second surface 81b and the ground surface 95 is weak, the ground surface 95 may peel off from the second surface 81b due to this torsional stress. However, the adhesive layer 87 of this embodiment firmly holds the ground surface 95 to the second surface 81b.

[0101] Furthermore, the adhesive layer 87 is attached to the second surface 81b through the plurality of through holes 101. In this case, the adhesive layer 87 is disposed inside each of the plurality of through holes 101 and on the second surface 81b of the base layer 81. The adhesive layer 87 is attached to the inner surface 95b of each of the plurality of through holes 101. Therefore, the adhesive layer 87 supports the inner surface 95b of the ground plane 95 that defines the through holes 101, and restricts the ground plane 95 from moving relative to the second surface 81b in the directions (X direction and Y direction) along the second surface 81b. Through the above, the FPC 37 of this embodiment can suppress the ground plane 95 from peeling off from the second surface 81b.

[0102] Additionally, during the manufacturing of FPC37, the cover layer 85 and adhesive layer 87 sometimes contain moisture. This moisture, for example, expands when heated in the furnace during solder S reflow, potentially causing the ground plane 95 to peel off from the second surface 81b. However, the ground plane 95 of this embodiment facilitates the removal of this moisture.

[0103] For example, the ground plane 95 does not overlap with the housing 71 and pads 91C of the repeater connector 65. Furthermore, multiple through holes 101 are provided on the ground plane 95. Therefore, moisture from the cover layer 85 and the adhesive layer 87 can be discharged from the FPC 37 through the through holes 101 and the portion that does not overlap with the housing 71 and pads 91C. Therefore, the FPC 37 of this embodiment can suppress the ground plane 95 from peeling off the second surface 81b due to moisture.

[0104] The following is an example of a method for mounting the repeater connector 65 to the FPC37. However, the method for mounting the repeater connector 65 to the FPC37 is not limited to the following method, and other methods may also be used. First, solder paste (solder S) is supplied to a plurality of pads 91, for example, by printing or coating.

[0105] Next, repeater connectors 65 are assembled on multiple pads 91. Reinforcing plate 67 supports repeater connectors 65 via FPC 37, thereby preventing deformation of FPC 37 during installation.

[0106] Next, the FPC37 is heated in a reflow oven, and the solder paste melts. This causes the contact portion 75 of the pin 72 to engage with the pad 91. At this time, flux, sometimes mixed in with the solder S or supplied separately, flows out from the solder S.

[0107] Next, the FPC37 is cleaned, for example, by ultrasonic cleaning. The FPC37 is placed in a tank filled with cleaning fluid. The cleaning fluid flows in the gap G between the FPC37 and the housing 71 of the relay connector 65, removing substances such as flux that could contaminate the HDD10.

[0108] The ground plane 95 overlaps with at least one of the plurality of pads 91. Therefore, the ground plane 95 can prevent the pads 91 from sinking as the housing 71 approaches the FPC37. Consequently, the gap G is kept relatively large, allowing cleaning fluid to flow easily within the gap G.

[0109] For example, the cleaning fluid transmits ultrasonic waves. These ultrasonic waves cause the flux present in gap G to float from FPC37. Then, FPC37 is removed from the cleaning fluid. At this point, the cleaning fluid and flux are discharged from gap G together. Through the above process, the installation of repeater connector 65 onto FPC37 is completed.

[0110] In the HDD 10 of the first embodiment described above, the magnetic head 48 is configured to read and write information relative to the disk 12. An FPC 37 is electrically connected to the magnetic head 48. A relay connector 65 is mounted on the FPC 37. The FPC 37 has a base layer 81, conductive layers 82 and 83, a cover layer 85, and an adhesive layer 87. The conductive layer 82 is disposed on a first surface 81a of the base layer 81. The conductive layer 83 is disposed on a second surface 81b of the base layer 81 located opposite to the first surface 81a. The cover layer 85 covers the second surface 81b and the conductive layer 83. The adhesive layer 87 bonds the cover layer 85 to the second surface 81b and the conductive layer 83. The conductive layer 82 has pads 91A. A plurality of through holes 101 are provided in the conductive layer 83, with a mesh portion 100A overlapping the base layer 81 and the pads 91A. The adhesive layer 87 is attached to the second surface 81b through the plurality of through holes 101. The relay connector 65 has pins 72A that engage with pad 91A.

[0111] Generally, compared to the case where two resins adhere to each other, the metal that forms the conductive layers 82 and 83 and the resin that forms the base layer 81, cover layers 84 and 85, and adhesive layers 86 and 87 are less likely to form chemical bonds and thus adhere weakly to each other. For example, when the repeater connector 65 generates a torque relative to the surface of the FPC 37, a force acts in the direction along the surface near the pad 91A of the FPC 37. This force also acts on the adhesive portion between the second surface 81b of the base layer 81 and the conductive layer 83. However, in this embodiment, the adhesive layer 87 is attached to the second surface 81b through a plurality of through holes 101 provided in the conductive layer 83. Therefore, the adhesive layer 87 is able to hold the conductive layer 83 more firmly to the second surface 81b compared to the case where it is only attached around the conductive layer 83. Therefore, the FPC 37 can suppress the conductive layer 83 from peeling off from the second surface 81b due to the aforementioned force. Furthermore, during the manufacturing of FPC37, moisture mixed within the cover layer 85 and adhesive layer 87 can be discharged to the outside through the through-hole 101. Therefore, FPC37 can prevent the conductive layer 83 from peeling off from the second surface 81b due to the aforementioned moisture. Through the above, the HDD10 of this embodiment can improve the reliability of FPC37.

[0112] The mesh portion 100B, separated from the mesh portion 100A, in the conductive layer 83 is provided with a plurality of through holes 101. The adhesive layer 87 is attached to the second surface 81b through the plurality of through holes 101. That is, the adhesive layer 87 can not only hold the area near the pad 91A, but also other parts of the conductive layer 83 to the second surface 81b more firmly. Therefore, the FPC37 can prevent the conductive layer 83 from peeling off from the second surface 81b.

[0113] The conductive layer 83 has a ground plane 95. The ground plane 95 has a mesh portion 100A. That is, a plurality of through holes 101 are provided in the portion of the ground plane 95 that overlaps with the pad 91A across the base layer 81. The adhesive layer 87 is attached to the second surface 81b through the plurality of through holes 101, thereby enabling the ground plane 95 to be more firmly held to the second surface 81b. Therefore, the HDD 10 of this embodiment can provide the ground plane 95 in a larger area of ​​the second surface 81b, thereby improving the transmission characteristics such as the impedance of the conductive layer 82.

[0114] The conductive layer 82 has pads 91B. A plurality of through-holes 101 are provided in the ground plane 95, overlapping the pads 91B with the base layer 81. The adhesive layer 87 is attached to the second surface 81b through the plurality of through-holes 101. The relay connector 65 has pins 72B that engage with the pads 91B. That is, the adhesive layer 87 can hold a portion near a pad 91A in a ground plane 95 to the second surface 81b through the through-holes 101, and also holds a portion near a pad 91B in a ground plane 95 to the second surface 81b through the through-holes 101. By holding the ground plane 95 to the second surface 81b at multiple locations, the adhesive layer 87 can more reliably prevent the ground plane 95 from peeling off from the second surface 81b. Therefore, the HDD 10 of this embodiment can provide a larger area of ​​the ground plane 95 on the second surface 81b.

[0115] The conductive layer 82 has wiring 92B. A plurality of through holes 101 are provided in the ground plane 95, overlapping the wiring 92B with the base layer 81. The adhesive layer 87 is attached to the second surface 81b through the plurality of through holes 101. That is, the adhesive layer 87 can hold a portion near the pad 91A in a ground plane 95 to the second surface 81b through the through holes 101, and also hold a portion near the wiring 92B in a ground plane 95 to the second surface 81b through the through holes 101. By holding the ground plane 95 to the second surface 81b at multiple locations, the adhesive layer 87 can more reliably prevent the ground plane 95 from peeling off from the second surface 81b. Therefore, the HDD 10 of this embodiment can provide a larger area of ​​the ground plane 95 on the second surface 81b.

[0116] The housing 11 houses the disk 12, the read / write head 48, the FPC 37, and the relay connector 65. The PCB 17 is located outside the housing 11. The relay connector 53 is mounted on the PCB 17. The relay device 66 is disposed in the housing 11 and electrically connected to the relay connector 53. The relay connector 65 is electrically connected to the relay device 66. The PCB 17 is electrically connected to the FPC 37 via the relay connector 53, the relay device 66, and the relay connector 65. For example, when the relay connector 65 is connected to the relay device 66, if the relay connector 65 generates a torque relative to the surface of the FPC 37 such as rotation (torsion) relative to the FPC 37, a force along the direction of the surface acts near the pad 91A of the FPC 37. However, as described above, the FPC 37 of this embodiment can suppress the conductive layer 83 from peeling off from the second surface 81b due to this force.

[0117] The repeater connector 65 has a housing 71 and a plurality of pins 72 protruding from the housing 71 and arranged in a column L1. Pins 72A are included in the plurality of pins 72 and are located at the ends of the column L1. For example, when a torque is generated such as when the repeater connector 65 rotates (torsively) relative to the surface of the FPC 37, the displacement of the pins 72A at the ends of the column is greater than the displacement of the other pins in the center of the column. Therefore, a larger force is applied near the pads 91A of the FPC 37. However, as described above, the FPC 37 of this embodiment is able to suppress the conductive layer 83 from peeling off from the second surface 81b due to this force.

[0118] In this embodiment, the HDD 10 has, for example, 10 or more disks 12. In this case, the number of HGA 36 also increases, as does the number of pins 72 on the relay connector 65. Furthermore, due to the increased functionality of the HDD 10, the number of pins 72 also increases. When the number of pins 72 is large, the distance between the center and the end pins 72A of the relay connector 65 becomes longer, and the displacement of pins 72A becomes larger. However, as described above, the FPC 37 of this embodiment is able to suppress the conductive layer 83 from peeling off from the second surface 81b near the pins 72A and the pads 91A.

[0119] The conductive layer 82 has pads 91C. The conductive layer 83 is separated from the portion of the base layer 81 that overlaps with the pads 91C. The relay connector 65 has pins 72C that engage with the pads 91C. The relay connector 65 is electrically connected to the magnetic head 48, outputting a write signal corresponding to the information written by the magnetic head 48 to the disk 12 from the pins 72C, or inputting a read signal corresponding to the information read by the magnetic head 48 from the disk 12 from the magnetic head 48 to the pins 72C. That is, the conductive layer 83 does not cover the pads 91C that transmit the write or read signals. Therefore, the HDD 10 of this embodiment can suppress the conductive layer 83 from affecting the transmission of the write or read signals. In addition, during the manufacture of the FPC 37, moisture mixed inside the cover layer 85 and the adhesive layer 87 can be discharged to the outside through the portion of the base layer 81 not covered by the conductive layer 83. Therefore, the FPC 37 can suppress the conductive layer 83 from peeling off from the second surface 81b due to the aforementioned moisture.

[0120] The repeater connector 65 has a housing 71. Pins 72A protrude from the housing 71. The conductive layer 83 has a ground plane 95 separated from the portion of the base layer 81 that overlaps with the housing 71. That is, the ground plane 95 does not cover the housing 71. Therefore, during the manufacture of the FPC 37, moisture mixed within the cover layer 85 and the adhesive layer 87 can be discharged to the outside through the portion of the base layer 81 not covered by the ground plane 95. Thus, the FPC 37 can prevent the conductive layer 83 from peeling off from the second surface 81b due to the aforementioned moisture.

[0121] (Second Implementation)

[0122] The following is for reference Figure 6 The second embodiment will be described. Furthermore, in the following description of the embodiments, components having the same function as the previously described components will be labeled with the same reference numerals, and sometimes further descriptions will be omitted. Additionally, multiple components labeled with the same reference numerals are not limited to having all the same functions and properties; they may also have different functions and properties corresponding to each embodiment.

[0123] Figure 6 This is an illustrative cross-sectional view schematically representing a portion of the HDD10 in the second embodiment. (Example) Figure 6 As shown, the conductive layer 82 of the second embodiment has at least one mesh portion 200. The mesh portion 200 is a portion of the conductive layer 82 that is separated from the plurality of pads 91. For example, the mesh portion 200 is a ground plane. The mesh portion 200 may also be other portions such as wiring 92.

[0124] The mesh portion 200 has been meshed. That is, a plurality of through holes 201 are provided in the mesh portion 200. The plurality of through holes 201 is an example of a plurality of fifth through holes. The plurality of through holes 201 penetrate the mesh portion 200 in a generally Z direction.

[0125] The adhesive layer 86 is attached to the first surface 81a of the base layer 81 through a plurality of through holes 201. The adhesive layer 87 is also attached to the surface 82a of the conductive layer 82 and the inner surface 82b of the conductive layer 82 that defines the through holes 201.

[0126] Similar to adhesive layer 87, adhesive layer 86 is weakly bonded to the surface 82a and inner surface 82b of conductive layer 82, but firmly bonded to the first surface 81a of substrate layer 81. Furthermore, by attaching adhesive layer 86 to multiple inner surfaces 82b, the contact area between adhesive layer 86 and conductive layer 82 is set to be large. Additionally, adhesive layer 86 enters multiple through holes 201, thus creating an anchoring effect. Therefore, the overall adhesive force between adhesive layer 86 and conductive layer 82 is improved.

[0127] In this embodiment, at least one mesh portion 200 in the conductive layer 82 is meshed, and a plurality of through holes 201 are provided. On the other hand, other portions of the conductive layer 82 are not meshed. However, it is also possible to mesh other portions of the conductive layer 82, or even to mesh the entire area of ​​the conductive layer 82.

[0128] In the HDD10 of the second embodiment described above, the FPC37 has a cover layer 84 and an adhesive layer 86. The cover layer 84 covers a portion of the first surface 81a and the conductive layer 82. The adhesive layer 86 bonds the cover layer 84 to the first surface 81a and the conductive layer 82. A plurality of through holes 201 are provided in the mesh portion 200 of the conductive layer 82, which is separated from the pads 91A. The adhesive layer 86 is attached to the first surface 81a through the plurality of through holes 201. Therefore, the adhesive layer 86 is such that, compared to the case where it is only attached around the conductive layer 82 to the first surface 81a, it can more firmly hold the conductive layer 82 to the first surface 81a. Therefore, the FPC37 can suppress the conductive layer 82 from peeling off from the first surface 81a. Furthermore, during the manufacture of the FPC37, moisture mixed inside the base layer 81, the cover layer 85, and the adhesive layer 87 can be discharged to the outside through the through holes 201. Therefore, FPC37 can suppress the conductive layer 82 from peeling off the first surface 81a due to the aforementioned moisture. Through the above, the HDD10 of this embodiment can improve the reliability of FPC37.

[0129] Several embodiments of the present invention have been described, but these embodiments are given by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other ways, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments or variations thereof are included in the scope or spirit of the invention, and are included within the scope of the invention described in the claims and their equivalents.

Claims

1. A disk device comprising: disk; The read / write head is configured to read and write information relative to the disk. A flexible printed circuit board is electrically connected to the magnetic head; as well as Electronic components are mounted on the flexible printed circuit board. The flexible printed circuit board has a first insulating layer, a first conductive layer disposed on a first surface of the first insulating layer, a second conductive layer disposed on a second surface of the first insulating layer located on the opposite side of the first surface, a second insulating layer covering the second surface and the second conductive layer, and a first adhesive layer for bonding the second insulating layer to the second surface and the second conductive layer. The first conductive layer has a first connecting pad. A plurality of first through holes are provided in the first portion of the second conductive layer that overlaps with the first connecting disk, separated by the first insulating layer. The first adhesive layer is attached to the second surface through the plurality of first through holes. The electronic component has a first pin that engages with the first connecting disk.

2. The disk device according to claim 1, wherein, A plurality of second through holes are provided in the second portion of the second conductive layer that is separated from the first portion. The first adhesive layer is attached to the second surface through the plurality of second through holes.

3. The disk device according to claim 1, wherein, The second conductive layer has a ground plane. The ground plane has the first portion.

4. The disk device according to claim 3, wherein, The first conductive layer has a second connecting pad. A plurality of third through holes are provided in the third portion of the ground plane that overlaps with the second connecting plate through the first insulating layer. The first adhesive layer is attached to the second surface through the plurality of third through holes. The electronic component has a second pin that engages with the second connecting disk.

5. The disk device according to claim 3, wherein, The first conductive layer has a first wiring. A plurality of fourth through holes are provided in the fourth portion of the ground plane that overlaps with the first wiring through the first insulating layer. The first adhesive layer is attached to the second surface through the plurality of fourth through holes.

6. The disk device according to claim 1, wherein, The flexible printed circuit board has a third insulating layer covering a portion of the first surface and the first conductive layer, and a second adhesive layer for bonding the third insulating layer to the first surface and the first conductive layer. Multiple fifth through holes are provided in the portion of the first conductive layer that is separated from the first connecting disk. The second adhesive layer is attached to the first surface through the plurality of fifth through holes.

7. The disk device according to claim 1, wherein, It also has: The housing encloses the disk, the read / write head, the flexible printed circuit board, and the electronic components. The substrate is located outside the housing; A first connector is mounted on the substrate; as well as A relay device is disposed in the housing and electrically connected to the first connector. The electronic component has a second connector that is electrically connected to the relay device.

8. The disk device according to claim 1, wherein, The electronic component has an insulating part and a plurality of pins protruding from the insulating part and arranged in a column. The first pin is included in the plurality of pins and is located at the end of the column.

9. The disk device according to claim 1, wherein, The first conductive layer has a third connecting disk. The second conductive layer separates from the portion of the first insulating layer that overlaps with the third connecting disk. The electronic component has a third pin that engages with the third connection disk. The electronic component is electrically connected to the read / write head and outputs a write signal from the third pin to the read / write head corresponding to the information written by the read / write head to the disk, or inputs a read signal from the read / write head to the third pin corresponding to the information read by the read / write head from the disk.

10. The disk device according to claim 1, wherein, The electronic component has insulating parts. The first pin protrudes from the insulating component. The second conductive layer has a ground plane that is separate from the portion of the first insulating layer that overlaps with the insulating component.

11. The disk device according to claim 1, wherein, The first conductive layer has a second wiring that is connected to the first connecting pad. The width of the first portion along the first surface is greater than the width of the second wiring along the first surface.

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