Disk drive

Abstract

To provide a disk device capable of suppressing defects in bounding two flexible printed circuit boards.SOLUTION: A disk device according to one embodiment includes a first flexible printed circuit board and a second flexible circuit board. The first flexible printed circuit board has: a first insulating layer; a second insulating layer; a first conductive layer arranged between the first insulating layer and the second insulating layer; and a first terminal provided on the first conductive layer. The second flexible printed circuit board has: a first surface facing the second insulating layer; a second surface located on the opposite side of the first surface; and a second terminal provided on the first surface and bonded to the first terminal by a bonded body. A magnetic head is mounted. The second surface has a dark color portion that is less bright than a portion where the second insulating layer covers the first conductive layer, out of the first flexible printed board.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] Embodiments of the present invention relate to a disk device.

Background Art

[0002] A disk device such as a hard disk drive (HDD) has a magnetic disk and a magnetic head for reading and writing information to and from the magnetic disk. For example, a plurality of flexible printed circuit boards (FPCs) electrically connect between a control device that controls the HDD and the magnetic head. The two FPCs are connected to each other by joining the terminals of one FPC and the terminals of the other FPC with solder.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When the terminals of two FPCs are joined with solder, the solder is heated, for example, by laser light. If the periphery of the terminals is overheated by the laser light, there is a risk that the FPC will be charred or peeled off. On the other hand, if the FPC is not heated sufficiently, there is a risk that the insufficiently melted solder will not join the terminals together.

[0005] An example of the problem to be solved by the present invention is to provide a disk device capable of suppressing defects in the joining of two flexible printed circuit boards.

Means for Solving the Problems

[0006] A disk drive according to one embodiment comprises a first flexible printed circuit board and a plurality of second flexible printed circuit boards. The first flexible printed circuit board has a first insulating layer, a second insulating layer covering the first insulating layer, a first conductive layer located between the first insulating layer and the second insulating layer, and a plurality of first terminals provided on the first conductive layer, with a plurality of holes provided in the second insulating layer to expose the plurality of first terminals. Each of the plurality of second flexible printed circuit boards has a first surface facing the second insulating layer, a second surface located on the opposite side of the first surface, and a plurality of second terminals provided on the first surface, each of which is joined to a corresponding one of the plurality of first terminals by a conductive bonding body, and a magnetic head is mounted on each of them. The second surface of at least one of the plurality of second flexible printed circuit boards has a dark-colored portion of the first flexible printed circuit board where the second insulating layer covers the first conductive layer, with a lower brightness than the portion of the first flexible printed circuit board where the second insulating layer covers the first conductive layer. [Brief explanation of the drawing]

[0007] [Figure 1] Figure 1 is an illustrative perspective view showing a schematic HDD according to the first embodiment. [Figure 2] Figure 2 is a schematic diagram illustrating the FPC and flexi-shape of the first embodiment. [Figure 3] Figure 3 is an illustrative plan view schematically showing a part of the FPC and a part of the flexi-shaft of the first embodiment. [Figure 4] Figure 4 is an illustrative plan view schematically showing the tail and joint of the first embodiment. [Figure 5] Figure 5 is an exemplary cross-sectional view schematically showing the tail and joint of the first embodiment along the line F5-F5 in Figure 4. [Figure 6] Figure 6 is an illustrative plan view schematically showing a part of the FPC and a part of the flexure according to the second embodiment. [Figure 7]Figure 7 is an illustrative plan view schematically showing a part of the FPC and a part of the flexure according to the third embodiment. [Modes for carrying out the invention]

[0008] (First embodiment) The first embodiment will be described below with reference to Figures 1 to 5. Note that in this specification, the components of the embodiment and their descriptions may be described using multiple expressions. The components and their descriptions are examples and are not limited by the expressions used herein. Components may also be identified by names different from those used herein. Furthermore, components may also be described using expressions different from those used herein.

[0009] Figure 1 is an illustrative perspective view showing a hard disk drive (HDD) 1 according to the first embodiment. HDD 1 is an example of a disk device. Note that the disk device is not limited to HDD 1, but may be other disk devices such as a hybrid hard disk drive.

[0010] As shown in Figure 1, the HDD1 includes a housing 11, a plurality of magnetic disks 12, a spindle motor 13, a clamp spring 14, a plurality of magnetic heads 15, a head stack assembly (HSA) 16, a voice coil motor (VCM) 17, a ramp load mechanism 18, and a flexible printed circuit board (FPC) 19. The FPC 19 is an example of a first flexible printed circuit board.

[0011] The housing 11 has a bottom wall 11a formed in a plate shape and a side wall 11b protruding from the outer edge of the bottom wall 11a. The housing 11 further has a cover attached to the side wall 11b that covers the inside of the housing 11. The housing 11 houses the magnetic disk 12, spindle motor 13, clamp spring 14, magnetic head 15, HSA 16, VCM 17, ramp load mechanism 18, and at least a portion of the FPC 19.

[0012] The magnetic disk 12 is, for example, a disk having a magnetic recording layer provided on at least one of its upper and lower surfaces. The diameter of the magnetic disk 12 is, for example, 3.5 inches, but is not limited to this example.

[0013] The spindle motor 13 supports and rotates multiple magnetic disks 12 that are stacked with spacing between them. A clamp spring 14 holds the multiple magnetic disks 12 to the hub of the spindle motor 13.

[0014] The magnetic head 15 records and reproduces information on the recording layer of the magnetic disk 12. In other words, the magnetic head 15 reads and writes information to the magnetic disk 12. The magnetic head 15 is mounted on the HSA 16.

[0015] The HSA16 is rotatably supported on a support shaft 21 positioned away from the magnetic disk 12. The VCM17 rotates the HSA16 to the desired position. As the rotation of the HSA16 by the VCM17 moves the magnetic head 15 to the outermost edge of the magnetic disk 12, the ramp load mechanism 18 holds the magnetic head 15 in the unloaded position away from the magnetic disk 12.

[0016] A printed circuit board (PCB) is mounted on the outside of the bottom wall 11a of the enclosure 11. A control device for controlling the spindle motor 13, magnetic head 15, and VCM 17 is mounted on this PCB.

[0017] The control unit includes various electronic components, such as a read / write channel (RWC), hard disk controller (HDC), processor, RAM, ROM, buffer memory, and servo combo IC. The control unit is electrically connected to the magnetic head 15 and VCM 17 via an FPC 19.

[0018] The HSA16 comprises an actuator block 31, a plurality of arms 32, and a plurality of head gimbal assemblies (HGAs) 33. The HGAs 33 may also be referred to as suspensions.

[0019] The actuator block 31 is rotatably supported on the support shaft 21 via a bearing, for example. The plurality of arms 32 protrude from the actuator block 31 in a direction substantially orthogonal to the support shaft 21. Note that the HSA 16 may be divided and the plurality of arms 32 may protrude from each of the plurality of actuator blocks 31.

[0020] The plurality of arms 32 are arranged at intervals in the direction in which the support shaft 21 extends. Each of the arms 32 is formed in a plate shape that can enter between adjacent magnetic disks 12. The plurality of arms 32 extend substantially in parallel.

[0021] The voice coil of the VCM 17 is provided on a protrusion protruding from the actuator block 31. The VCM 17 has a pair of yokes, a voice coil disposed between the yokes, and a magnet provided on the yokes.

[0022] The HGA 33 is attached to the tip portion of the corresponding arm 32 and protrudes from the arm 32. Thus, the plurality of HGAs 33 are arranged at intervals in the direction in which the support shaft 21 extends.

[0023] FIG. 2 is an exemplary diagram schematically showing the FPC 19 and the flexure 43 of the first embodiment. Each of the plurality of HGAs 33 has the base plate 41 and the load beam 42 shown in FIG. 1, and the flexure 43 and the preamplifier 44 shown in FIG. 2. That is, the HDD 1 has a plurality of flexures 43. Further, the magnetic head 15 is mounted on the HGA 33. The flexure 43 is an example of a second flexible printed circuit board and may also be referred to as an intermediate FPC. The preamplifier 44 may also be referred to as a head IC or a head amplifier.

[0024] The base plate 41 in Figure 1 is formed in a plate shape and is attached to the tip of the arm 32. The load beam 42 is formed in a plate shape that is thinner than the base plate 41. The load beam 42 is attached to the tip of the base plate 41 and protrudes from the base plate 41.

[0025] As shown in Figure 2, the flexia 43 is formed in an elongated strip shape. Note that the shape of the flexia 43 is not limited to this example. The flexia 43 is a flexible laminated substrate. The flexia 43 has a gimbal 51, a tail 52, and an intermediate section 53. The tail 52 is an example of a strip.

[0026] The gimbal 51 is provided at one end of the flexi-sha 43. The tail 52 is provided at the other end of the flexi-sha 43. The intermediate section 53 extends between the gimbal 51 and the tail 52.

[0027] The magnetic head 15 is mounted on the gimbal 51. The gimbal 51 is mounted on the load beam 42 so as to be displaceable on the load beam 42. The gimbal 51 is displaced in accordance with the displacement of the magnetic head 15, and also in accordance with the driving of, for example, a piezoelectric element.

[0028] The intermediate section 53 extends from the gimbal 51 and protrudes outward from the base plate 41 and the load beam 42. The intermediate section 53 extends along the arm 32 toward the actuator block 31.

[0029] The tail 52 is formed in a substantially rectangular shape extending in the longitudinal direction of the intermediate portion 53. The tail 52 has a plurality of pads 55. The pads 55 are an example of a second terminal. The pads 55 are arranged at intervals in the longitudinal direction of the tail 52 to form a flying lead.

[0030] The flexure 43 further has a plurality of wires 56. The wires 56 extend through the intermediate section 53 between the gimbal 51 and the tail 52. Each of the plurality of wires 56 electrically connects at least one of the plurality of pads 55 to a lead element, light element, heater, or other component of the magnetic head 15. In other words, the wires 56 extend between the pads 55 and the electrodes connected to the magnetic head 15, forming at least a portion of the electrical path between the pads 55 and the magnetic head 15.

[0031] Figure 3 is an illustrative plan view schematically showing a part of the FPC 19 and a part of the flexure 43 of the first embodiment. As shown in Figure 3, the FPC 19 has a joint portion 61 and an extension portion 62.

[0032] The joint 61 is provided at one end of the FPC 19. The joint 61 is attached to the actuator block 31, for example, by a plurality of screws 65. The other end of the FPC 19 is electrically connected to the PCB on which the control device described above is mounted, for example, through a connector provided on the bottom wall 11a. The extension 62 extends between the joint 61 and the connector. As shown in Figure 1, a portion of the extension 62 is bent in a substantially arc shape. By flexing, the extension 62 can absorb the displacement of the joint 61 due to the rotation of the HSA 16.

[0033] As shown in Figure 3, the tails 52 of multiple flexi-shafts 43 are attached to the joint 61 of the FPC 19. The FPC 19 electrically connects the PCB on which the control device described above is mounted to the flexi-shafts 43. In other words, the control device is electrically connected to the magnetic head 15 via the PCB, the FPC 19, and the flexi-shafts 43.

[0034] Figure 4 is an exemplary plan view schematically showing the tail 52 and joint 61 of the first embodiment. Figure 5 is an exemplary cross-sectional view schematically showing the tail 52 and joint 61 of the first embodiment along the line F5-F5 in Figure 4.

[0035] As shown in Figure 5, the FPC 19 has, for example, a base layer 71, two conductive layers 72 and 73, two cover layers 74 and 75, and a metal plate 76. Adhesive layers are interposed between the multiple layers of the FPC 19. Note that the FPC 19 is not limited to this example; it may have fewer or more layers.

[0036] The base layer 71 is an example of a first insulating layer. The conductive layer 72 is an example of a first conductive layer. The conductive layer 73 is an example of a second conductive layer. The cover layer 74 is an example of a second insulating layer.

[0037] The base layer 71 and cover layers 74, 75 are, for example, flexible and insulating films made of a synthetic resin such as polyimide or polyester. The base layer 71 has two surfaces 71a and 71b that are on opposite sides to each other. Surface 71b faces the actuator block 31.

[0038] The conductive layers 72 and 73 are made of a conductive metal, such as copper. Conductive layer 72 is laminated on surface 71a of base layer 71. Conductive layer 73 is laminated on surface 71b of base layer 71. Therefore, base layer 71 is located between the two conductive layers 72 and 73.

[0039] The cover layer 74 is laminated on the surface 71a of the base layer 71 and the conductive layer 72. That is, the cover layer 74 covers at least a portion of the surface 71a of the base layer 71 and at least a portion of the conductive layer 72. The conductive layer 72 is located between the base layer 71 and the cover layer 74.

[0040] The cover layer 75 is laminated on the surface 71b of the base layer 71 and the conductive layer 73. That is, the cover layer 75 covers at least a portion of the surface 71b of the base layer 71 and at least a portion of the conductive layer 73. Therefore, the base layer 71 is located between the two cover layers 74 and 75.

[0041] The metal plate 76 is made of, for example, stainless steel. The metal plate 76 is attached to the cover layer 75 of the joint 61. This makes the joint 61 substantially flat. The metal plate 76 is attached to the actuator block 31.

[0042] The joint portion 61 of the FPC 19 has an outer surface 61a. The outer surface 61a is one surface of the joint portion 61 and is formed, for example, by a cover layer 74 and a conductive layer 72 and a part of the base layer 71 exposed by holes in the cover layer 74. The outer surface 61a may be formed by other parts.

[0043] As shown in Figure 5, the outer surface 61a may have microscopic irregularities. However, macroscopically, the outer surface 61a is formed to be substantially flat. As shown in several drawings, including Figure 3, assuming that the outer surface 61a is flat, the X, Y, and Z axes are defined herein for convenience. The X, Y, and Z axes are orthogonal to each other. The X axis is provided along the width of the outer surface 61a. The Y axis is provided along the length of the outer surface 61a. The Z axis is provided perpendicular to the outer surface 61a.

[0044] Furthermore, the X, Y, and Z directions are defined herein. The X direction is a direction along the X axis and includes the +X direction indicated by the X-axis arrow and the -X direction which is the opposite direction of the X-axis arrow. The Y direction is a direction along the Y axis and includes the +Y direction indicated by the Y-axis arrow and the -Y direction which is the opposite direction of the Y-axis arrow. The Z direction is a direction along the Z axis and includes the +Z direction indicated by the Z-axis arrow and the -Z direction which is the opposite direction of the Z-axis arrow.

[0045] The X and Y directions are directions along the outer surface 61a. The X and Y directions are orthogonal to each other. The Z direction is a direction perpendicular to the outer surface 61a. The X direction is an example of a second direction. The Y direction is an example of a first direction.

[0046] The joint portion 61 may bend so that its outer surface 61a is curved, or so that its outer surface 61a has irregularities macroscopically. In this case, the X direction is the width direction of the joint portion 61 along the outer surface 61a, and the Y direction is the length direction of the joint portion 61 along the outer surface 61a.

[0047] As shown in Figure 4, at the joint 61, the conductive layer 72 has a plurality of pads 81, a plurality of wirings 82, and a plurality of vias 83. In other words, the plurality of pads 81 are provided on the conductive layer 72. The pads 81 are an example of a first terminal.

[0048] The pads 81 are provided on the outer surface 61a. Specifically, as shown in Figure 5, each of the multiple pads 81 is exposed to the outside of the FPC 19 through holes 85 provided in the cover layer 74. This ensures that the pads 81 are provided on the outer surface 61a.

[0049] As shown in Figure 3, the multiple pads 81 are arranged in six columns in the Y direction. In other words, the multiple pads 81 form six columns Lpc. In the example in Figure 3, each column Lpc contains six of the multiple pads 81 arranged in the Y direction. Note that the number of columns Lpc of pads 81 and the number of multiple pads 81 contained in each column Lpc are not limited to this example.

[0050] In each row Lpc, multiple pads 81 are arranged with spacing in the Y direction. Similarly, multiple rows Lpc of pads 81 are arranged with spacing in the X direction. The number of pads 81 in each row Lpc corresponds, for example, to the function of the magnetic head 15.

[0051] As shown in Figure 4, each of the multiple wires 82 extends from a multiple pad 81. In this embodiment, at least one of the multiple wires 82 connects the corresponding pad 81 to the preamplifier 44. In addition, at least one of the multiple wires 82 connects the corresponding pad 81 to the corresponding via 83.

[0052] The conductive layer 73 has a plurality of wirings 88. The conductive layer 73 may also have other parts, such as a ground plane. In this embodiment, the wirings 88 connect the via 83 to the preamplifier 44.

[0053] The tails 52 of multiple flexia 43 are mounted on multiple columns Lpc of pad 81. The tails 52 of the multiple flexia 43 extend in the Y direction and cover multiple pads 81 of the corresponding columns Lpc. Thus, the tails 52 of the multiple flexia 43 are aligned with spacing in the X direction to form a column Lfx. Column Lfx contains six tails 52 aligned in the X direction.

[0054] As shown in Figure 5, each of the multiple pads 55 of the tail 52 is joined to the corresponding one of the multiple pads 81 of the corresponding row Lpc by solder S. Solder S is conductive and is an example of a bonding agent. Solder S can be leaded or lead-free. The bonding agent is not limited to solder S, but may be, for example, silver paste, solder, or conductive adhesive.

[0055] Each of the multiple flexi-shas 43 has a base layer 91, a conductive layer 92, a cover layer 93, and a metal plate 94. The metal plate 94 may also be called a backing plate or backing layer. In addition, layers of adhesive are interposed between the multiple layers of the flexi-sha 43. Note that the flexi-sha 43 is not limited to this example and may have fewer or more layers.

[0056] The base layer 91 and the cover layer 93 are, for example, flexible and insulating films made of a synthetic resin such as polyimide or polyester. The base layer 91 has two surfaces 91a and 91b that are on opposite sides of each other. Surface 91a faces the outer surface 61a of the joint 61.

[0057] The conductive layer 92 is made of a conductive metal, such as copper. The conductive layer 92 is laminated onto the surface 91a of the base layer 91. The cover layer 93 is laminated onto the surface 91a of the base layer 91 and the conductive layer 92. That is, the cover layer 93 covers at least a portion of the surface 91a of the base layer 91 and at least a portion of the conductive layer 92.

[0058] The metal plate 94 is made of a metal such as stainless steel or aluminum. The metal plate 94 is attached to the surface 91b of the base layer 91. Therefore, the base layer 91 is located between the conductive layer 92 and the metal plate 94.

[0059] The tail 52 has two outer surfaces 52a and 52b located on opposite sides of each other. Outer surface 52a is an example of a first surface. Outer surface 52b is an example of a second surface. Outer surface 52a is one surface of the tail 52 and is formed, for example, by a cover layer 93 and a conductive layer 92 and a base layer 91 exposed by holes in the cover layer 93. Outer surface 52b is the other surface of the tail 52 and is formed, for example, by a metal plate 94 and a base layer 91 exposed by holes in the metal plate 94. Note that outer surfaces 52a and 52b may be formed by other parts.

[0060] As shown in Figure 5, the outer surfaces 52a and 52b may have microscopic irregularities. However, macroscopically, the outer surfaces 52a and 52b are formed to be approximately flat and are arranged along the XY plane. Therefore, the X and Y directions are along the directions of the outer surfaces 52a and 52b.

[0061] The outer surfaces 52a and 52b of the tail 52 are approximately parallel to the outer surface 61a of the joint 61. However, the outer surfaces 52a and 52b of the tail 52 and the outer surface 61a of the joint 61 do not have to be parallel. In this case, the direction along the outer surfaces 52a and 52b of the tail 52 is an example of the first and second directions.

[0062] The outer surface 52a faces the outer surface 61a of the joint 61. In other words, the outer surface 52a faces the cover layer 74. The outer surface 52a is spaced apart from the cover layer 74 in the +Z direction. However, the outer surface 52a may be in contact with the cover layer 74.

[0063] Multiple pads 55 are provided in the conductive layer 92. In other words, the conductive layer 92 has multiple pads 55. Each of the multiple pads 55 is exposed to the outside of the flexure 43 through holes 101 provided in the cover layer 93. As a result, the pads 55 are provided on the outer surface 52a.

[0064] Each of the multiple pads 55 has a plating 103. Furthermore, multiple platings 104 corresponding to the multiple pads 55 are provided on the surface 91b of the base layer 91. The platings 103 and 104 are made of, for example, gold.

[0065] A through-hole 105 is provided in the FPC 19. The through-hole 105 penetrates the base layer 91, the pad 55, and the plating 104. The solder S that joins the pad 55 and the pad 81 also adheres to the plating 104 through the through-hole 105.

[0066] A slit 107 is provided in the metal plate 94. The slit 107 penetrates the metal plate 94 in the Z direction and extends approximately in the Y direction. The slit 107 exposes multiple platings 104 and a portion of the base layer 91 surrounding the multiple platings 104 to the outside of the tail 52.

[0067] As described above, the outer surface 52b of the tail 52 in this embodiment is formed by the portion of the surface 91b of the base layer 91 exposed by the slit 107, the metal plate 94, and the plating 104. In other words, a portion of the outer surface 52b is provided on each of the portion of the surface 91b of the base layer 91 exposed by the slit 107, the metal plate 94, and the plating 104. Note that the outer surface 52b is not limited to this example.

[0068] As shown in Figure 3, the multiple flexia 43 may be individually referred to as flexia 43A, 43B, 43C, 43D, 43E, and 43F. Each of flexia 43A and 43F is one of the multiple flexia 43 located at the end of column Lfx. Flexia 43B, 43C, 43D, and 43E are located between flexia 43A and 43F. Flexia 43C and 43D are located between flexia 43B and 43E.

[0069] Flexia 43A and 43F are formed mirror-symmetrically with respect to each other. Flexia 43B and 43E are formed mirror-symmetrically with respect to each other. Furthermore, flexia 43C and 43D are formed mirror-symmetrically with respect to each other. Therefore, the following description will mainly focus on flexia 43A, 43B, and 43C.

[0070] As shown in Figure 4, the width WA of the tail 52 in the X direction of flexia 43A is greater than the width WB of the tail 52 in the X direction of flexia 43B. Also, the width WB is greater than the width WC of the tail 52 in the X direction of flexia 43C. In other words, among the multiple flexia 43s, flexia 43A has a greater width in the X direction than flexia 43B and 43C, which are closer to the center of column Lfx than the ends of column Lfx. Thus, at least two of the multiple flexias 43 have different tail widths in the X direction.

[0071] Furthermore, the length LA of the tail 52 in the Y direction of flexia 43A is longer than the length LB of the tail 52 in the Y direction of flexia 43B. Also, length LB is longer than the length LC of the tail 52 in the Y direction of flexia 43C. Thus, at least two of the multiple flexia 43 have different lengths of tail 52 in the Y direction.

[0072] The outer surface 52b of the tail 52 of flexures 43A, 43B, 43E, and 43F has a dark-colored portion 111. The hatching in Figures 3 and 4 does not represent a cross-section, but rather indicates the dark-colored portion 111 for convenience.

[0073] Furthermore, the outer surface 52b of the tail 52 of flexia 43B, 43C, 43D, and 43E has a light-colored portion 112. That is, the tail 52 of flexia 43B and 43E has both a dark-colored portion 111 and a light-colored portion 112.

[0074] In this embodiment, a portion of the outer surface 52b of the metal plate 94 has at least one of the dark portion 111 and the light portion 112. The dark portion 111 and the light portion 112 are not limited to this example and may be provided, for example, on the portion of the surface 91b of the base layer 91 that is exposed by the slit 107.

[0075] In this embodiment, the dark portion 111 is, for example, a colored portion of the metal plate 94. The light portion 112 is, for example, an uncolored portion of the metal plate 94. The lightness of the light portion 112 is higher than the lightness of the dark portion 111.

[0076] The dark-colored portion 111 is, for example, a film (plating) of nickel or another metal formed on the surface of the metal plate 94 by electroless plating. The dark-colored portion 111 is not limited to this example. For example, the dark-colored portion 111 may be a paint applied to the surface of the metal plate 94, an oxide film formed on the surface of the metal plate 94 by laser marking, or an oxide film formed on the surface of the metal plate 94 by annealing.

[0077] Furthermore, the dark portion 111 may be a part of the metal plate 94 made of a different material than the light portion 112. For example, the light portion 112 of the metal plate 94 may be made of stainless steel, and the dark portion 111 may be made of graphite.

[0078] The color of the dark area 111 is, for example, black. However, the color of the dark area 111 may be any other color with a lower brightness than the color of the light area 112. Furthermore, the color of the dark area 111 is not limited to a single color; it may consist of multiple colors or have a gradient.

[0079] The light-colored portion 112 is formed from, for example, the material of the metal plate 94. Therefore, the color of the light-colored portion 112 is, for example, the metallic color of stainless steel or aluminum. However, the color of the light-colored portion 112 is not limited to this example.

[0080] In the Flexia 43A and 43F, the dark-colored portion 111 is provided over the entire outer surface 52b of the metal plate 94. In this embodiment, the color of the portion of the metal plate 94 of the Flexia 43A and 43F that is included in the gimbal 51 and intermediate portion 53 is the same color as the dark-colored portion 111. That is, the entire outer surface of the metal plate 94 of the Flexia 43A and 43F is the dark-colored portion 111. Note that the gimbal 51 and intermediate portion 53 do not need to be colored.

[0081] The metal plate 94 of Flexia 43C and 43D is not colored. That is, in Flexia 43C and 43D, the light-colored portion 112 is provided over the entire outer surface 52b of the metal plate 94. Therefore, the brightness of the dark-colored portion 111 is lower than the brightness of the outer surface 52b in one of the multiple Flexia 43 (Flexia 43C or Flexia 43D).

[0082] Flexia 43B and 43E are partially colored. In Flexia 43B and 43E, the dark area 111 has multiple dark regions 115, and the light area 112 has multiple light regions 116.

[0083] Each of the multiple dark regions 115 is aligned in the X direction with a corresponding one of the multiple pads 55. In other words, at least a portion of the dark region 115 and at least a portion of the corresponding pad 55 are located at the same position in the Y direction. In this embodiment, the multiple dark regions 115 are arranged in two rows in the Y direction. Each of the multiple pads 55 is located between two adjacent dark regions 115 in the X direction.

[0084] Multiple dark areas 115 and multiple light areas 116 are arranged alternately in the Y direction. Therefore, the light areas 112 are spaced further apart from the multiple pads 55 than the dark areas 111. In the Y direction, at least one of the multiple light areas 116 is located between two adjacent dark areas 115 and between two adjacent pads 55.

[0085] The metal plate 94 has two inner edges 94a and two outer edges 94b. The two inner edges 94a are part of the inner edge of the metal plate 94 that forms the slit 107 and extend substantially linearly in the substantially Y direction. The outer edges 94b are part of the outer edge of the metal plate 94 and extend substantially linearly in the substantially Y direction. The two inner edges 94a are located between the two outer edges 94b.

[0086] The metal plates 94 of the flexures 43A, 43B, 43E, and 43F further have a plurality of protrusions 94c. The plurality of protrusions 94c project in the X direction from the outer edge 94b. The plurality of protrusions 94c are spaced apart from each other in the Y direction.

[0087] Each of the multiple protrusions 94c is aligned in the X direction with a corresponding one of the multiple pads 55. Each of the multiple dark areas 115 is located between the inner edge 94a and the tip of the protrusion 94c. In other words, a portion of the dark area 115 is located on the protrusion 94c. On the other hand, each of the multiple light areas 116 is located between the inner edge 94a and the outer edge 94b. That is, the dark area 111 has a greater width in the X direction than the light area 112.

[0088] The base layer 71 and cover layers 74 and 75 of the FPC19 are capable of partially transmitting light. Therefore, as shown in Figure 5, the conductive layer 72 can be seen through the cover layer 74. Furthermore, the conductive layer 73 can be seen through both the cover layer 74 and the base layer 71.

[0089] The color of the conductive layers 72 and 73 becomes darker, for example, as they are viewed through multiple layers or thicker layers. Therefore, when common light illuminates the outer surface 61a of the junction 61, the brightness of the conductive layer 73 as seen through the cover layer 74 and base layer 71 is lower than the brightness of the conductive layer 72 as seen through the cover layer 74. In other words, the brightness of the portion of the FPC 19 where the cover layer 74 and base layer 71 cover the conductive layer 73 is lower than the brightness of the portion where the cover layer 74 covers the conductive layer 72.

[0090] When a common light illuminates the outer surface 52b of the tail 52 and the outer surface 61a of the joint 61, the brightness of each of the multiple dark regions 115 of the dark portion 111 is lower than the brightness of the conductive layer 72 as seen through the cover layer 74. In other words, the brightness of each of the multiple dark regions 115 is lower than the brightness of the portion of the FPC 19 where the cover layer 74 covers the conductive layer 72.

[0091] Furthermore, the brightness of each of the multiple dark regions 115 is lower than the brightness of the conductive layer 73 as seen through the cover layer 74 and the base layer 71. In other words, the brightness of each of the multiple dark regions 115 is lower than the brightness of the portion of the FPC 19 where the cover layer 74 and the base layer 71 cover the conductive layer 73.

[0092] In this embodiment, each of the multiple dark regions 115 has a lower brightness than the lowest brightness portion of the FPC 19 visible from outside the FPC 19. Note that the dark regions 115 are not limited to this example.

[0093] The surface roughness of the dark-colored portion 111 is greater than the surface roughness of the conductive layer 72 and also greater than the surface roughness of the conductive layer 73. In other words, the surface roughness of at least a portion of the outer surface 52b of at least one of the multiple flexures 43 is greater than the surface roughness of the conductive layers 72 and 73.

[0094] For example, the maximum height Rz of the dark area 111 is greater than 0.8 μm. Furthermore, the arithmetic mean roughness Ra of the dark area 111 is greater than 0.15 μm. Note that the maximum height Rz and arithmetic mean roughness Ra of the dark area 111 are not limited to this example.

[0095] In this embodiment, the surface roughness of the dark portion 111 is greater than that of the light portion 112. However, the surface roughness of the dark portion 111 and the surface roughness of the light portion 112 may be the same.

[0096] During the assembly of the HDD1 described above, the pad 55 of the flexisha 43 is joined to the pad 81 of the FPC 19 by solder S. For example, a paste containing solder S is applied to one of the pads 55 or 81. Next, the tail 52 of the flexisha 43 and the joint 61 of the FPC 19 are placed on top of each other, and the paste adheres to the other of the pads 55 or 81.

[0097] Next, for example, the laser beam LL shown in Figure 3 is irradiated onto the tail 52 and the joint 61. The laser beam LL in Figure 3 is an area laser and irradiates a relatively wide area of ​​the tail 52 and the joint 61. Note that the laser beam LL is not limited to this example.

[0098] The laser beam LL is irradiated onto the tail 52 and the joint 61, and also onto the solder S through the through hole 105. Heat is transferred from the tail 52 and the joint 61, which are heated by the laser beam LL, to the solder S. Furthermore, the solder S is directly heated by the laser beam LL. As a result, the paste melts, and the pad 55 and the pad 81 are joined by the solder S.

[0099] The outer surface 52b of the tail 52 and the outer surface 61a of the joint 61 receive the laser light LL. That is, the dark-colored portion 111 and the light-colored portion 112 of the outer surface 52b receive the laser light LL and absorb the laser light LL.

[0100] Areas with lower brightness absorb light and heat up more easily than areas with higher brightness. In other words, areas with higher brightness reflect light more easily than areas with lower brightness. For this reason, the dark-colored areas 111 of the outer surface 52b are heated to a higher temperature by the laser light LL than the light-colored areas 112.

[0101] Of the tail 52 and joint 61 irradiated with laser light LL, the central part AH tends to become hotter than other parts. The central part AH includes at least one flexiser 43 (e.g., flexisers 43B, 43C, 43D, 43E) from among the multiple flexisers 43 that are close to the center of row Lfx, and includes at least one of the multiple pads 55 of said flexiser 43B, 43C, 43D, 43E that are close to the center.

[0102] The central part AH tends to become hot because the heat applied by the laser beam LL is not easily released. On the other hand, the part outside the central part AH releases heat easily and tends to become cold. For this reason, in the tail 52 and joint 61 irradiated with the laser beam LL, the central part AH generally tends to become hot.

[0103] In this embodiment, among the rows Lfx, flexures 43C and 43D have light-colored portions 112 but do not have dark-colored portions 111. Therefore, the outer surface 52b of the tails 52 of flexures 43C and 43D absorbs less laser light LL and does not become hotter than the outer surface 52b of flexures 43A, 43B, 43E, and 43F.

[0104] Among the rows Lfx, flexures 43B and 43E have multiple dark regions 115 of the dark portion 111 and multiple light regions 116 of the light portion 112. Each of the multiple dark regions 115 is adjacent to a corresponding pad 55. Therefore, the outer surface 52b of the tail 52 readily absorbs laser light LL in the vicinity of the pad 55. However, the outer surface 52b readily absorbs laser light LL at positions spaced away from the pad 55.

[0105] The portion of the tail 52 near the pad 55 is heated to a high temperature by the laser beam LL, heating the solder S. This allows the solder S to melt efficiently. On the other hand, the light-colored region 116, which is spaced away from the pad 55, is at a lower temperature than the dark-colored region 115. Therefore, the portion of the tail 52 that includes the light-colored region 116 does not easily become hot. In other words, even when the tail 52 is irradiated with the laser beam LL, which is an area laser, the portion near the pad 55 can be selectively heated.

[0106] Among the rows Lfx, flexures 43A and 43F have dark-colored areas 111 but no light-colored areas 112. Therefore, the outer surface 52b of the tails 52 of flexures 43A and 43F easily absorbs laser light LL and tends to become hot.

[0107] Flexia 43C and 43D are narrower and shorter than Flexia 43A and 43F. Furthermore, Flexia 43C and 43D do not have the protrusion 94c, while Flexia 43A and 43F do. As a result, Flexia 43A and 43F have a larger surface area of ​​the outer surface 52b that can receive the laser beam LL than Flexia 43C and 43D.

[0108] Furthermore, the surface roughness of the dark-colored portion 111 is greater than that of the light-colored portion 112. As a result, the surface area of ​​the outer surface 52b that can receive the laser beam LL of Flexia 43A and 43F is even larger than that of Flexia 43C and 43D.

[0109] As described above, the flexures 43C and 43D located within the central part AH are less likely to heat up, while the flexures 43A and 43F located outside the central part AH are more likely to heat up. Therefore, the temperature distribution of the tail 52 and the joint 61 irradiated with laser light LL becomes more uniform.

[0110] The laser light LL irradiated onto the outer surface 61a of the joint 61 heats the joint 61. Similar to the flexure 43, the parts of the joint 61 with lower brightness absorb light and heat up more easily than the parts with higher brightness.

[0111] On the outer surface 61a of the joint 61, the conductive layer 72 is visible through the cover layer 74, and the conductive layer 73 is visible through the cover layer 74 and the base layer 71. Because the conductive layer 72 is visible through the cover layer 74, the portion of the joint 61 where the cover layer 74 covers the conductive layer 72 forms a relatively dark portion of the joint 61. Furthermore, because the conductive layer 73 is visible through the cover layer 74 and the base layer 71, the portion of the joint 61 where the cover layer 74 and the base layer 71 cover the conductive layer 73 forms an even darker portion of the joint 61. On the other hand, the portion of the joint 61 where the conductive layers 72 and 73 are not provided forms a lighter portion than the portion where the conductive layers 72 and 73 are provided.

[0112] The portion of the joint 61 that includes the conductive layer 73 is the portion of the joint 61 that has the lowest brightness when irradiated with the laser light LL. On the other hand, the portion of the joint 61 that does not have the conductive layers 72 and 73 is the portion of the joint 61 that has the highest brightness when irradiated with the laser light LL. Note that the joint 61 is not limited to this example.

[0113] The portion of the joint 61 that includes the conductive layer 72 is relatively dark in color, and therefore heats up to a relatively high temperature when exposed to laser light LL. Furthermore, the portion of the joint 61 that includes the conductive layer 73 is even darker in color, and therefore reaches an even higher temperature.

[0114] In other words, the laser light LL irradiated onto the joint 61 is absorbed and reflected by the conductive layer 72 through the cover layer 74. Furthermore, the laser light LL is absorbed and reflected by the conductive layer 73 through the cover layer 74 and the base layer 71. The laser light LL is absorbed by the cover layer 74 and the base layer 71. For this reason, the portion of the joint 61 that includes the conductive layer 73 tends to become hotter than the portion that includes the conductive layer 72.

[0115] When a common laser beam LL is irradiated onto the outer surfaces 52b and 61a, the brightness of each of the multiple dark regions 115 is lower than the brightness of the portion of the joint 61 where the cover layer 74 and base layer 71 cover the conductive layer 73. Furthermore, the dark regions 115 have a rougher surface than the conductive layer 73 and are more likely to absorb the laser beam LL. For this reason, when the laser beam LL is irradiated onto the tail 52 and the joint 61, the temperature of the joint 61 becomes lower than the temperature of the dark regions 115.

[0116] If the FPC 19 is overheated, for example, the conductive layers 72 and 73 may peel off from the base layer 71, or the outer surface 61a of the joint 61 may scorch. However, in this embodiment, the lowest brightness portion of the joint 61 has a higher brightness than the dark color region 115. Therefore, the joint 61 is less likely to heat up, and peeling and scorching can be suppressed.

[0117] On the other hand, if the solder S is not heated sufficiently, it may not melt completely. For example, even if the solder S melts completely in the central part AH, it may not melt completely outside the central part AH. However, in this embodiment, the flexures 43A and 43F located outside the central part AH have a dark colored region 115 and are easily heated. Therefore, the solder S applied to the pads 55 of the flexures 43A and 43F can be melted more reliably.

[0118] For example, if the flexure 43 is excessively heated in the central part AH, peeling and charring may occur in the flexure 43 as well. However, in this embodiment, the flexures 43C and 43D located in the central part AH have a light-colored portion 112 and are less likely to be heated. Therefore, the flexures 43C and 43D are less likely to be heated, and the occurrence of peeling and charring can be suppressed.

[0119] In the HDD1 according to the first embodiment described above, the FPC19 has a conductive layer 72 and a plurality of pads 81. The conductive layer 72 is located between the base layer 71 and the cover layer 74. The plurality of pads 81 are provided on the conductive layer 72 and exposed by a plurality of holes 85 provided on the cover layer 74. Each of the plurality of flexures 43 has outer surfaces 52a, 52b and a plurality of pads 55. The outer surface 52a faces the cover layer 74. The outer surface 52b is located on the opposite side of the outer surface 52a. The plurality of pads 55 are provided on the outer surface 52a and each is joined to a corresponding one of the plurality of pads 81 by conductive solder S. Generally, in the assembly of the HDD1, the solder S is melted by laser light LL irradiated over a relatively wide area of ​​the outer surface 52b, for example, to join the pads 81 and pads 55. The cover layer 74 of the FPC19 is also exposed to laser light LL. Therefore, a portion of the FPC 19 may be overheated, potentially causing charring and peeling. Alternatively, a portion of the FPC 19 may not be sufficiently heated, resulting in insufficient solder S not bonding the pad 81 and the pad 55. In contrast, in the HDD 1 of this embodiment, the outer surface 52b of at least one of the multiple flexiar 43 has a dark-colored portion 111. The brightness of this dark-colored portion 111 is lower than the brightness of the portion of the FPC 19 where the cover layer 74 covers the conductive layer 72. That is, the brightness of at least a portion of the outer surface 52b is set low. The lower the brightness of the portion irradiated with laser light LL, the higher the absorption rate of the laser light LL. Therefore, the flexiar 43 having the dark-colored portion 111 efficiently absorbs the laser light LL. Consequently, the HDD 1 can efficiently heat the solder S that bonds the pad 81 of the FPC 19 and the pad 55 of the flexiar 43, and the melting of the solder S by the laser light LL can be shortened. By shortening the irradiation time of the laser beam LL, HDD1 can suppress excessive heating of a portion of the FPC 19, thereby suppressing charring and peeling of the FPC 19. Furthermore, by setting the brightness of the outer surface 52b to a low level at least in positions that are less likely to be heated, HDD1 can suppress insufficient melting of the solder S. As described above, HDD1 of this embodiment can suppress defects in the bonding between FPC 19 and flexisha 43.

[0120] In at least one of the multiple flexures 43, the outer surface 52b has a light-colored portion 112 that is spaced further away from the multiple pads 55 than the dark-colored portion 111. The brightness of the light-colored portion 112 is higher than the brightness of the dark-colored portion 111. That is, the dark-colored portion 111 is located near the pads 55. Therefore, the HDD1 of this embodiment can efficiently heat the solder S that joins the pads 81 of the FPC 19 and the pads 55 of the flexure 43. Furthermore, the HDD1 can suppress excessive heating of the light-colored portion 112, which does not contribute much to the melting of the solder S. Thus, the HDD1 can suppress problems in the joining of the FPC 19 and the flexure 43.

[0121] Each of the multiple flexi-shas 43 has a tail 52 extending in the Y direction along its outer surface 52a. In the flexi-sha 43B, the tail 52 has a dark portion 111 and a light portion 112. The dark portion 111 has multiple dark regions 115. Each of the multiple dark regions 115 is aligned with one of the multiple pads 55, along the outer surface 52a and in the X direction perpendicular to the Y direction. The light portion 112 has multiple light regions 116. The multiple dark regions 115 and the multiple light regions 116 are arranged alternately in the Y direction. As a result, the HDD1 of this embodiment can efficiently heat the solder S that joins the pads 81 of the FPC 19 and the pads 55 of the flexi-sha 43. Furthermore, by alternately providing the easily heated dark regions 115 and the less easily heated light regions 116, the HDD1 can equalize the temperature distribution of the tail 52. Therefore, the tail 52 can be prevented from burning and peeling due to localized high temperatures.

[0122] The dark-colored portion 111 is aligned with the outer surface 52a and has a greater width in the X direction perpendicular to the Y direction than the light-colored portion 112. This allows for a larger area of ​​the dark-colored portion 111, which has a high absorption rate of laser light LL. Therefore, the HDD1 of this embodiment can efficiently heat the solder S that joins the pad 81 of the FPC 19 and the pad 55 of the flexure 43.

[0123] Of the multiple flexi-shas 43, at least flexi-shas 43A and 43C have different tail widths WA and WC in the X direction. Generally, the wider the tail width 52, the larger the area of ​​the outer surface 52b. That is, the wider the tail width 52, the higher the absorption rate of the laser light LL. In this embodiment, the HDD1 can equalize the temperature distribution of the heated FPC 19 and the multiple flexi-shas 43 by setting a wider tail width for flexi-sha 43A, which is less likely to be heated among the multiple flexi-shas 43. That is, the multiple solders S can be heated substantially evenly and sufficiently. Therefore, the HDD1 can suppress defects in the bonding between the FPC 19 and the flexi-shas 43.

[0124] Multiple flexisers 43 are arranged in the X direction to form a column Lfx. Generally, flexisers 43 located at the ends of column Lfx dissipate heat more easily. In contrast, in the HDD1 of this embodiment, flexiser 43A, located at the end of column Lfx, has a wider tail 52 in the X direction than flexiser 43C, which is closer to the center of the column than the end of column Lfx. Therefore, the HDD1 of this embodiment can equalize the temperature distribution of the heated FPC 19 and the multiple flexisers 43. Consequently, the HDD1 can suppress defects in the connection between the FPC 19 and the flexisers 43.

[0125] Of the multiple flexors 43, at least flexors 43A and 43C have different tail lengths in the Y direction. Generally, the longer the tail 52, the larger the surface area of ​​the outer surface 52b. That is, the longer the tail 52, the higher the absorption rate of the laser light LL. In this embodiment, the HDD1 can equalize the temperature distribution of the heated FPC 19 and the multiple flexors 43 by setting the tail 52 of flexor 43A, which is less likely to heat up, to be longer. Therefore, the HDD1 can suppress defects in the bonding between the FPC 19 and the flexors 43.

[0126] The brightness of the dark portion 111 is lower than the brightness of the outer surface 52b (light portion 112) of flexor 43C, one of the multiple flexors 43. In other words, in flexor 43C, one of the multiple flexors 43, the dark portion 111 is not provided, and the overall brightness of the outer surface 52b is set relatively high. As a result, the HDD1 of this embodiment can suppress excessive heating of the flexor 43.

[0127] Each of the multiple flexi-shas 43 has a metal plate 94 on which at least a portion of the outer surface 52b is provided. The dark-colored portion 111 is provided on the metal plate 94. This allows the dark-colored portion 111 to be easily formed, for example, by plating or the formation of an oxide film.

[0128] The dark-colored portion 111 is provided over the entire outer surface 52b of the metal plate 94 in the flexi-sha 43A. This allows the dark-colored portion 111 to be easily formed by, for example, coloring at least one surface of the metal plate 94 all at once by plating or forming an oxide film.

[0129] The FPC 19 has a conductive layer 73. The base layer 71 is located between the conductive layer 72 and the conductive layer 73. The brightness of the dark area 111 is lower than the brightness of the part of the FPC 19 where the base layer 71 and the cover layer 74 cover the conductive layer 73. The brightness of the part of the FPC 19 where the conductive layer 73 is visible through two insulating layers (base layer 71 and cover layer 74) is lower than the brightness of the part of the FPC 19 where the conductive layer 72 is visible through one cover layer 74. In other words, the brightness of the dark area 111 is set lower in the flexure 43. Therefore, the HDD 1 can more efficiently heat the solder S that joins the pad 81 of the FPC 19 and the pad 55 of the flexure 43. In this embodiment, the brightness of the portion where two insulating layers (base layer 71 and cover layer 74) of the FPC 19 cover the conductive layer 73 is shown to be lower than the brightness of the portion where the cover layer 74 covers the conductive layer 72. However, the light absorption rate of the base layer 71 may be lower than the light absorption rate of the cover layer 74.

[0130] The surface roughness of at least a portion of the flexure 43, such as the dark-colored portion 111, is greater than the surface roughness of the conductive layer 72. Generally, the greater the surface roughness, the larger the surface area that absorbs the laser light LL, and the higher the absorption rate of the laser light LL. Therefore, the HDD 1 of this embodiment can efficiently heat the solder S that joins the pad 81 of the FPC 19 and the pad 55 of the flexure 43.

[0131] In the first embodiment described above, the outer surfaces of the metal plates 94 of flexisers 43A and 43F are colored entirely, the outer surfaces of the metal plates 94 of flexisers 43B and 43E are partially colored, and the outer surfaces of the metal plates 94 of flexisers 43C and 43D are not colored. However, the outer surfaces of the metal plates 94 of all flexisers 43 may be colored entirely, or the outer surfaces of the metal plates 94 of all flexisers 43 may be partially colored.

[0132] Furthermore, in the first embodiment described above, the surface roughness of the dark-colored portion 111 is greater than the surface roughness of the conductive layers 72 and 73. However, the portion of the outer surface 52b of the tail 52 with greater surface roughness may be different from the dark-colored portion 111.

[0133] (Second embodiment) A second embodiment will be described below with reference to Figure 6. In the following descriptions of multiple embodiments, components having the same function as those already described will be denoted by the same reference numerals as those previously described, and their descriptions may be omitted. Furthermore, multiple components denoted by the same reference numerals do not necessarily share all functions and properties; they may have different functions and properties depending on the embodiment.

[0134] Figure 6 is an exemplary plan view schematically showing a portion of the FPC 19 and a portion of the flexure 43 according to the second embodiment. As shown in Figure 6, the plurality of flexures 43 in the second embodiment include flexures 43G and 43H instead of flexures 43B and 43E. Flexures 43G and 43H are substantially equivalent to flexures 43B and 43E, except as described below.

[0135] Each of the tails 52 of the flexure 43G and 43H has an intermediate section 201 and two end sections 202. The intermediate section 201 is an example of a first section. The end sections 202 are an example of a second section.

[0136] The intermediate section 201 is the portion of the tail 52 of the flexure 43G, 43H that has multiple pads 55. The two end sections 202 are portions of the tail 52 of the flexure 43G, 43H that are located outside the intermediate section 201 and spaced apart from the multiple pads 55. The two end sections 202 are provided at both ends of the tail 52 in the Y direction. Therefore, the intermediate section 201 is located between the two end sections 202 in the Y direction.

[0137] The end portion 202 has a dark region 115 of the dark portion 111. The end portion 202 may also have a light portion 112. On the other hand, the intermediate portion 201 does not have a dark portion 111, but has a light region 116 of the light portion 112. Therefore, the lightness of the outer surface 52b of the tail 52 in the intermediate portion 201 is higher than the lightness of the dark portion 111.

[0138] When laser light LL is irradiated onto flexures 43G and 43H, the end portion 202 becomes hotter than the intermediate portion 201. The heat from the end portion 202 is transferred to the intermediate portion 201 by thermal conduction. In other words, the intermediate portion 201 is heated more by thermal conduction from the end portion 202 than by direct heating from the laser light LL. For this reason, the intermediate portion 201 is less likely to become hotter than the end portion 202.

[0139] Among the multiple pads 55, the pad 55 located near the end portion 202 is located outside the central portion AH. Therefore, generally, the pad 55 located near the end portion 202 is less likely to be heated. However, heat from the end portion 202 preferentially moves to the pad 55 located near the end portion 202. Consequently, the pad 55 located outside the central portion AH can also be sufficiently heated.

[0140] In the HDD1 of the second embodiment described above, among the plurality of flexors 43, flexors 43G and 43H have an intermediate portion 201 and an end portion 202. The intermediate portion 201 has a plurality of pads 55. The end portion 202 is located outside the intermediate portion 201 and is spaced apart from the plurality of pads 55. The end portion 202 has a dark color portion 111. The brightness of the outer surface 52b of the intermediate portion 201 is higher than the brightness of the dark color portion 111. That is, the brightness of the outer surface 52b near the plurality of pads 55 is higher than the brightness of the outer surface 52b at a position spaced apart from the plurality of pads 55 (end portion 202). Therefore, the HDD1 of this embodiment can suppress excessive heating of the flexor 43 near the pads 55. Furthermore, generally speaking, the further away from the center of the plurality of pads 55, the higher the possibility that the solder S will not melt sufficiently. On the other hand, in the HDD1 of this embodiment, end portions 202 having dark-colored portions 111 are provided at positions far from the center of the multiple pads 55, which effectively suppresses insufficient melting of the solder S. As described above, the HDD1 of this embodiment can suppress defects in the joining of the FPC 19 and the flexi 43.

[0141] (Third embodiment) A third embodiment will be described below with reference to Figure 7. Figure 7 is an exemplary plan view schematically showing a portion of the FPC 19 and a portion of the flexi-shaft 43 according to the third embodiment. As shown in Figure 7, the plurality of flexi-shafts 43 of the third embodiment include flexi-shafts 43I, 43J, 43K, 43L, 43M, and 43N instead of flexi-shafts 43A, 43B, 43C, 43D, 43E, and 43F. Flexi-shafts 43I, 43J, 43K, 43L, 43M, and 43N are substantially equivalent to flexi-shafts 43A, 43B, 43C, 43D, 43E, and 43F, except as described below.

[0142] The outer surface 52b of the tail 52 of Flexia 43I, 43J, 43K, 43L, 43M, and 43N has a dark-colored portion 111 and does not have a light-colored portion 112. However, Flexia 43I, 43J, 43K, 43L, 43M, and 43N are not limited to this example and may have a light-colored portion 112.

[0143] The width of the tail 52 of flexia 43I in the X direction is smaller than the width of the tail 52 of flexia 43J in the X direction. Also, the width of the tail 52 of flexia 43J is smaller than the width of the tail 52 of flexia 43K in the X direction. In other words, among the multiple flexia 43s, flexia 43I has a smaller width in the X direction than flexia 43K, which is closer to the center of column Lfx than the end of column Lfx.

[0144] For example, due to various conditions such as the arrangement of other components, the central part AH may tend to be colder than other parts. In this embodiment, the flexure 43K included in the central part AH has a larger area of ​​the outer surface 52b that can receive the laser beam LL than the flexure 43I. As a result, the temperature distribution of the tail 52 and the joint 61 irradiated with the laser beam LL becomes more uniform.

[0145] In the HDD1 of the third embodiment described above, the multiple flexisers 43 are arranged in the X direction to form a column Lfx. In the HDD1 of this embodiment, the flexiser 43I located at the end of the column Lfx has a smaller tail width 52 in the X direction than the flexiser 43K located closer to the center of the column than the end of the column Lfx. For example, if the flexiser 43I located at the end of the column Lfx is prone to overheating due to various factors, the HDD1 of this embodiment can equalize the temperature distribution of the heated FPC 19 and the multiple flexisers 43. Therefore, the HDD1 can suppress defects in the connection between the FPC 19 and the flexiser 43.

[0146] For the sake of explanation, the number of flexi-shapes 43 in the above embodiment is six. However, the HDD1 may have ten or more magnetic disks 12 and twenty or more flexi-shapes 43.

[0147] In the above description, suppression is defined, for example, as preventing the occurrence of an event, action, or effect, or reducing the degree of an event, action, or effect. Also in the above description, restriction is defined, for example, as preventing movement or rotation, or allowing movement or rotation within a predetermined range while preventing movement or rotation beyond that predetermined range.

[0148] While several embodiments of the present invention have been described, these embodiments are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be carried out in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0149] 1...Hard disk drive (HDD), 12...Magnetic disk, 15...Magnetic head, 19...Flexible printed circuit board (FPC), 43, 43A, 43B, 43C, 43D, 43E, 43F, 43G, 43H, 43I, 43J, 43K, 43L, 43M, 43N...Flexor, 52...Tail, 52b...Outer surface, 55...Pad, 61a...Outer surface, 71...Base layer, 72, 73...Conductive layer, 74...Cover layer, 81...Pad, 85...Hole, 94...Metal plate, 111...Dark area, 112...Light area, 115...Dark region, 116...Light region, S...Solder, Lfx...Row.

Claims

1. A first flexible printed circuit board comprising: a first insulating layer; a second insulating layer covering the first insulating layer; a first conductive layer located between the first insulating layer and the second insulating layer; and a plurality of first terminals provided on the first conductive layer, wherein the second insulating layer is provided with a plurality of holes exposing the plurality of first terminals, A plurality of second flexible printed circuit boards, each having a first surface facing the second insulating layer, a second surface located opposite to the first surface, and a plurality of second terminals provided on the first surface and each being joined to a corresponding one of the plurality of first terminals by a conductive bonding body, and each having a magnetic head mounted on it, It is equipped with, The second surface of at least one of the plurality of second flexible printed circuit boards has a dark area in the first flexible printed circuit board where the second insulating layer covers the first conductive layer, with a brightness lower than that of the second insulating layer covering the first conductive layer. Disk drive.

2. In at least one of the plurality of second flexible printed circuit boards, the second surface has a light-colored portion that is spaced further apart from the plurality of second terminals than the dark-colored portion. The brightness of the light-colored area is higher than the brightness of the dark-colored area. The disk device according to claim 1.

3. Each of the plurality of second flexible printed circuit boards has a strip extending in a first direction along the first surface, The band has the dark portion and the light portion, The dark area has multiple dark regions, Each of the plurality of dark regions is aligned with a corresponding one of the plurality of second terminals in a second direction that is along the first surface and perpendicular to the first direction. The aforementioned light-colored portion has a plurality of light-colored regions, The plurality of dark regions and the plurality of light regions are arranged alternately in the first direction, The disk device according to claim 2.

4. Each of the plurality of second flexible printed circuit boards has a strip extending in a first direction along the first surface, The band has the dark portion and the light portion, The dark portion has a width greater than that of the light portion in a second direction that is perpendicular to the first direction and is along the first surface. The disk device according to claim 2.

5. At least one of the plurality of second flexible printed circuit boards has a first portion having the plurality of second terminals, and a second portion located outside the first portion and spaced apart from the plurality of second terminals, The second portion has the dark colored portion, The brightness of the second surface in the first portion is higher than the brightness of the dark portion. The disk device according to claim 1.

6. Each of the plurality of second flexible printed circuit boards has a strip extending in a first direction along the first surface, At least two of the plurality of second flexible printed circuit boards have different widths of the strips in a second direction that is perpendicular to the first direction and along the first surface. The disk device according to claim 1.

7. The plurality of second flexible printed circuit boards are arranged in the second direction to form a row. Of the plurality of second flexible printed circuit boards, one located at the end of the row has a wider strip width in the second direction than one of the plurality of second flexible printed circuit boards that is closer to the center of the row than to the end of the row. The disk device according to claim 6.

8. The plurality of second flexible printed circuit boards are arranged in the second direction to form a row. Of the plurality of second flexible printed circuit boards, one located at the end of the row has a narrower width in the second direction than one of the plurality of second flexible printed circuit boards that is closer to the center of the row than the end of the row. The disk device according to claim 6.

9. Each of the plurality of second flexible printed circuit boards has a strip extending in a first direction along the first surface, At least two of the plurality of second flexible printed circuit boards have different lengths of the strips in the first direction. The disk device according to claim 1.

10. The brightness of the dark area is lower than the brightness of the second surface on one of the plurality of second flexible printed circuit boards. The disk device according to claim 1.

11. Each of the plurality of second flexible printed circuit boards has a metal plate on which at least a portion of the second surface is provided. The dark colored portion is provided on the metal plate, The disk device according to claim 1.

12. The dark-colored portion is provided over the entire area of ​​the second surface provided on the metal plate. The disk device according to claim 11.

13. The first flexible printed circuit board has a second conductive layer, The first insulating layer is located between the first conductive layer and the second conductive layer. The brightness of the dark area is lower than the brightness of the portion of the first flexible printed circuit board in which the first insulating layer and the second insulating layer cover the second conductive layer. A disk device according to any one of claims 1 to 12.

14. The surface roughness of the dark-colored portion is greater than the surface roughness of the first conductive layer. A disk device according to any one of claims 1 to 12.

15. A first flexible printed circuit board comprising: a first insulating layer; a second insulating layer covering the first insulating layer; a first conductive layer located between the first insulating layer and the second insulating layer; and a plurality of first terminals provided on the first conductive layer, wherein the second insulating layer is provided with a plurality of holes exposing the plurality of first terminals, A plurality of second flexible printed circuit boards, each having a first surface facing the second insulating layer, a second surface located opposite to the first surface, and a plurality of second terminals provided on the first surface and each being joined to a corresponding one of the plurality of first terminals by a conductive bonding body, and each having a magnetic head mounted on it, It is equipped with, The surface roughness of at least a portion of the second surface of at least one of the plurality of second flexible printed circuit boards is greater than the surface roughness of the first conductive layer. Disk drive.

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