disc device

Abstract

An embodiment of the present invention provides a disk device capable of suppressing peeling of a flexible printed circuit board. A disk device of one embodiment has a magnetic disk, a magnetic head, a first flexible printed circuit board, and a second flexible printed circuit board. The first flexible printed circuit board has a plurality of first terminals. The second flexible printed circuit board has a surface, a plurality of second terminals provided on the surface and joined to the plurality of first terminals by a joining body, and a first planar ground layer covering at least one of the plurality of second terminals in a direction orthogonal to the surface. The plurality of second terminals include a first read terminal. The first planar ground layer is separated from at least a portion of the first read terminal in a direction along the surface.

Description

[0001] Related application: This application enjoys priority based on Japanese Patent Application No. 2021-211073 (filed on December 24, 2021). This application incorporates the entire contents of that basic application by reference. Technical Field

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

[0003] A disk drive (HDD) has a disk and read / write heads that read and write information to that disk. For example, multiple flexible printed circuit boards (FPCs) electrically connect the HDD's control unit to the read / write heads. One FPC terminal is soldered to another, thereby connecting the two FPCs to each other.

[0004] When the terminals of two FPCs are joined by solder, the solder is heated, for example by a laser. If the periphery of the terminals is overheated by the solder, the FPC may peel off. Summary of the Invention

[0005] The present invention provides a disk device capable of suppressing the peeling of flexible printed circuit boards.

[0006] One embodiment of the disk apparatus includes a magnetic disk, a read / write head, a first flexible printed circuit board, and a second flexible printed circuit board. The read / write head is configured to read and write information relative to the magnetic disk. The first flexible printed circuit board has a plurality of first terminals on which the read / write head is mounted, and at least one of the plurality of first terminals is electrically connected to the read / write head. The second flexible printed circuit board has: a surface; a plurality of second terminals disposed on the surface and respectively connected to a corresponding one of the plurality of first terminals via a conductive bonding member; and a first planar ground layer covering at least one of the plurality of second terminals in a direction orthogonal to the surface. The plurality of second terminals includes a first read terminal in which an electrical signal representing information read by the read / write head from the magnetic disk flows. The first planar ground layer is separated from at least a portion of the first read terminal in a direction along the surface. Attached Figure Description

[0007] Figure 1 This is a schematic perspective view illustrating one embodiment of a hard disk drive.

[0008] Figure 2 This is an illustrative diagram schematically showing the FPC and flexible portion of the above-described embodiment.

[0009] Figure 3This is an illustrative plan view schematically showing a portion of the FPC and a portion of the flexible portion of the above-described embodiment.

[0010] Figure 4 This is an illustrative plan view schematically representing a portion of the FPC described in the above embodiments.

[0011] Figure 5 It is along Figure 4 The F5-F5 line schematically represents an exemplary cross-sectional view of a portion of the FPC and a portion of the flexible portion of the above embodiment. Detailed Implementation

[0012] The following is for reference Figures 1 to 5 One embodiment will be described. Furthermore, in this specification, the constituent elements of an 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 representation in this specification. Constituent elements can also be identified by names different from those used in this specification. Moreover, constituent elements can also be described in representations different from those used in this specification.

[0013] Figure 1 This is a schematic perspective view illustrating an embodiment of a hard disk drive (HDD) 1. HDD 1 is an example of a disk device. However, the disk device is not limited to HDD 1, and may also be other disk devices such as hybrid hard disk drives.

[0014] like Figure 1 As shown, HDD1 has a housing 11, multiple disks 12, a spindle motor 13, a clamping spring 14, multiple read / write heads 15, an actuator assembly 16, a voice coil motor (VCM) 17, a ramp loading mechanism 18, and a flexible printed circuit board (FPC) 19. FPC 19 is an example of a second flexible printed circuit board.

[0015] The housing 11 has a bottom wall 11a formed in the shape of a plate and a side wall 11b projecting from the outer edge of the bottom wall 11a. The housing 11 also has a cover that is mounted on the side wall 11b and covers the interior of the housing 11. The housing 11 houses at least a portion of the disk 12, spindle motor 13, clamping spring 14, magnetic head 15, actuator assembly 16, VCM 17, ramp loading mechanism 18, and FPC 19.

[0016] Disk 12 is, for example, a disk having a magnetic recording layer disposed on at least one of its upper and lower surfaces. The diameter of disk 12 is, for example, 3.5 inches, but is not limited to this example.

[0017] The spindle motor 13 supports and rotates a plurality of spaced-apart overlapping disks 12. Clamping springs 14 hold the plurality of disks 12 in the hub of the spindle motor 13.

[0018] The read / write head 15 records and reproduces information on the recording layer of the disk 12. In other words, the read / write head 15 reads and writes information on the disk 12. The read / write head 15 is supported by the actuator assembly 16.

[0019] The actuator assembly 16 is rotatably supported by a support shaft 21 configured at a position detached from the disk 12. The VCM 17 rotates the actuator assembly 16 and positions it in the desired location. When the actuator assembly 16 is rotated by the VCM 17 and the read / write head 15 moves to the outermost periphery of the disk 12, the ramp loading mechanism 18 holds the read / write head 15 in the unloaded position detached from the disk 12.

[0020] A printed circuit board (PCB) is mounted on the outside of the bottom wall 11a of the housing 11. A control device for controlling the spindle motor 13, the magnetic head 15, and the VCM 17 is mounted on the PCB.

[0021] The control unit includes various electronic components such as read / write channels (RWC), hard disk drives (HDC), processors, RAM, ROM, buffer memory, and servo combination ICs. The control unit is electrically connected to the read / write head 15 and VCM 17 via FPC 19.

[0022] The actuator assembly 16 includes an actuator block 31, multiple arms 32, and multiple head suspension assemblies 33. The head suspension assembly 33 may also be referred to as a head universal joint (HGA).

[0023] The actuator block 31 is rotatably supported by the support shaft 21, for example, via bearings. Multiple arms 32 protrude from the actuator block 31 in a direction substantially orthogonal to the support shaft 21. Alternatively, the actuator assembly 16 can be divided so that multiple arms 32 protrude from multiple actuator blocks 31 respectively.

[0024] Multiple arms 32 are spaced apart in the direction in which the support shaft 21 extends. Each arm 32 is formed into a plate shape that can enter between adjacent disks 12. The multiple arms 32 extend substantially parallel to each other.

[0025] A voice coil of VCM17 is provided on a protrusion extending from actuator block 31. VCM17 has a pair of yokes, a voice coil disposed between the yokes, and a magnet disposed on the yokes.

[0026] The head suspension assembly 33 is mounted on the front end portion of the corresponding arm 32 and protrudes from the arm 32. Thus, multiple head suspension assemblies 33 are spaced apart in the direction in which the support shaft 21 extends.

[0027] Figure 2This is a schematic diagram illustrating the FPC19 and the flexible portion 43 of this embodiment. The plurality of head suspension assemblies 33 each have... Figure 1 The base plate 41 and load beam 42 shown are shown. Figure 2 The diagram shows the flexible section 43, the preamplifier 44, and the HDI sensor 45. Furthermore, the magnetic head 15 is mounted on the magnetic head suspension assembly 33. The flexible section 43 is an example of a first flexible printed circuit board, also referred to as a relay FPC. The preamplifier 44 can also be referred to as a magnetic head IC or a magnetic head amplifier.

[0028] Figure 1 The base plate 41 is formed in the shape of a plate and is mounted on the front end of the arm 32. The load beam 42 is formed in the shape of a plate that is thinner than the base plate 41. The load beam 42 is mounted on the front end of the base plate 41 and protrudes from the base plate 41.

[0029] like Figure 2 As shown, the flexible portion 43 is formed in the shape of an elongated strip. However, the shape of the flexible portion 43 is not limited to this example. The flexible portion 43 may be, for example, a laminate having a metal plate (backing layer) such as stainless steel, an insulating layer formed on the metal plate, a conductive layer formed on the insulating layer and constituting multiple wirings (wiring pattern), and a protective layer (insulating layer) covering the conductive layer. The flexible portion 43 has a first mounting portion 51, a second mounting portion 52, and an intermediate portion 53.

[0030] The first mounting portion 51 is provided at one end of the flexible portion 43. The second mounting portion 52 is provided at the other end of the flexible portion 43. The intermediate portion 53 extends between the first mounting portion 51 and the second mounting portion 52.

[0031] The first mounting part 51 is mounted on the base plate 41 and the load beam 42. The first mounting part 51 has a universal joint (elastic support part) located on the load beam 42 and capable of displacement. The magnetic head 15 is mounted on the universal joint.

[0032] The middle portion 53 extends from the first mounting portion 51 toward the outer side of the side edge of the base plate 41. The middle portion 53 extends along the side edge of the arm 32 toward the actuator block 31 on the outer side of the base plate 41.

[0033] The second mounting portion 52 is formed in a rectangular shape extending along the length direction of the intermediate portion 53. The second mounting portion 52 has a plurality of pads 55. The pads 55 are an example of the first terminal. The pads 55 are arranged at intervals along the length direction of the second mounting portion 52 to form a suspended lead.

[0034] The flexible portion 43 also has multiple wirings 56. Pads 55 and wirings 56 are disposed on the conductive layer of the flexible portion 43. The wirings 56 extend through the intermediate portion 53 between the first mounting portion 51 and the second mounting portion 52. The multiple wirings 56 electrically connect at least one of the multiple pads 55 to a read element, write element, heater, or other component of the magnetic head 15. In other words, the wirings 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.

[0035] Figure 3 This is a schematic plan view illustrating a portion of the FPC19 and a portion of the flexible portion 43 in this embodiment. Figure 3 As shown, FPC19 has a joint 61, an extension 62, and a plurality of protrusions 63.

[0036] The joint 61 is mounted to the actuator block 31, for example, by a plurality of screws 65. The joint 61 is provided with a plurality of through holes 66 through which the screws 65 pass. An extension 62 extends between the joint 61 and the PCB on which the control device described above is mounted. A plurality of protrusions 63 protrude from the joint 61.

[0037] A second mounting portion 52 with multiple flexible portions 43 is installed at the joint 61 of the FPC19. The FPC19 electrically connects the PCB on which the control device described above is mounted to the flexible portions 43. That is, the control device is electrically connected to the magnetic head 15 via the PCB, the FPC19, and the flexible portions 43.

[0038] Figure 4 This is an illustrative plan view schematically showing a portion of the FPC19 of this embodiment. Figure 5 It is along Figure 4 The F5-F5 line schematically represents an exemplary cross-sectional view of a portion of the FPC19 and a portion of the flexible portion 43 in this embodiment.

[0039] like Figure 5 As shown, FPC19, for example, has a base layer 71, two conductive layers 72 and 73, and two capping layers 74 and 75. Furthermore, adhesive layers are sandwiched between the multiple layers of FPC19. However, FPC19 is not limited to this example and may have fewer or more layers.

[0040] The base layer 71 and the cover layers 74 and 75 are, for example, flexible and insulating films made of synthetic resins such as polyester or polyimide. The base layer 71 has two surfaces 71a and 71b disposed on opposite sides of each other. Surface 71b faces the actuator block 31.

[0041] Conductive layers 72 and 73 are made of a conductive metal, such as copper. Conductive layer 72 is stacked on surface 71a of substrate layer 71. Conductive layer 73 is stacked on surface 71b of substrate layer 71. Therefore, substrate layer 71 is located between the two conductive layers 72 and 73.

[0042] A capping layer 74 is stacked on surface 71a of the base layer 71 and on the conductive layer 72. That is, the capping layer 74 covers at least a portion of surface 71a of the base layer 71 and at least a portion of the conductive layer 72.

[0043] A capping layer 75 is stacked on surface 71b of the base layer 71 and the conductive layer 73. That is, the capping layer 75 covers at least a portion of 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 capping layers 74 and 75. Furthermore, for ease of explanation, Figure 4 The overlay layer 74 is omitted.

[0044] In the joint 61, a metal plate (backing layer) such as aluminum is mounted on the cover layer 75 of the FPC 19. Thus, the joint 61 is formed substantially flat. The joint 61 is mounted on the actuator block 31 via the metal plate. Figure 1 As shown, the extension 62 can absorb the displacement of the engagement 61 that accompanies the rotation of the actuator assembly 16 by flexing.

[0045] like Figure 3 As shown, the junction 61 of FPC19 has a surface 61a and two edges 61b and 61c. Surface 61a is one surface of the junction 61, and is formed, for example, by a cover layer 74, a conductive layer 72 exposed through holes in the cover layer 74, and a base layer 71. Alternatively, surface 61a may also be formed by other portions.

[0046] Such as including Figure 3 As shown in several accompanying figures, assuming surface 61a is flat, the X-axis, Y-axis, and Z-axis are defined in this specification for convenience. The X-axis, Y-axis, and Z-axis are orthogonal to each other. The X-axis is set along the width of surface 61a. The Y-axis is set along the length of surface 61a. The Z-axis is set orthogonally to surface 61a.

[0047] Furthermore, in this specification, the X, Y, and Z directions 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 on the X-axis in the opposite direction. 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 on the Y-axis in the opposite direction. 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 on the Z-axis in the opposite direction.

[0048] The X and Y directions are along the surface 61a. The X and Y directions intersect each other (orthogonal in this embodiment). The Z direction is orthogonal to the surface 61a. The X direction is an example of the second direction. The Y direction is an example of the first and third directions. Furthermore, the arrangement of the elements along the direction of the surface 61a in the following description is equivalent to the arrangement of the elements when viewed along the direction orthogonal to the surface 61a.

[0049] The joint 61 can also be flexed so that the surface 61a becomes curved or has unevenness. In this case, the X direction is along the width direction of the joint 61 on the surface 61a, and the Y direction is along the length direction of the joint 61 on the surface 61a.

[0050] Edge 61b of the joint 61 is located at the end of the joint 61 in the +Y direction. Edge 61c of the joint 61 is located at the end of the joint 61 in the -Y direction. The two edges 61b and 61c extend substantially parallel to each other along the X direction. A plurality of protrusions 63 protrude from edge 61b in the substantially +Y direction. The plurality of protrusions 63 are spaced apart from each other in the X direction. Extension 62 extends from edge 61c in the substantially -Y direction.

[0051] like Figure 4 As shown, in the junction 61, the conductive layer 72 has a plurality of connection pads 81, a plurality of mounting pads 82, a plurality of wirings 83, and a plurality of planar ground layers 84. The planar ground layer 84 is an example of a second planar ground layer. The planar ground layer 84 may also be referred to as a planar pattern or a ground plane.

[0052] Connecting pad 81 and mounting pad 82 are provided on surface 61a. Specifically, as follows: Figure 5 As shown, the connection pads 81 and mounting pads 82 are exposed to the outside of the FPC 19 through a plurality of holes 74a provided in the cover layer 74. Thus, the connection pads 81 and mounting pads 82 are provided on the surface 61a.

[0053] like Figure 4 As shown, the plurality of connecting pads 81 are closer to the edge 61b of the joint 61 than the plurality of mounting pads 82. The plurality of mounting pads 82 are located between the plurality of connecting pads 81 and the extension 62. Furthermore, the plurality of connecting pads 81 are closer to the edge 61b of the joint 61 than the screw 65.

[0054] exist Figure 3 In this example, multiple connection pads 81 are arranged in 6 columns in the Y direction. In other words, the multiple connection pads 81 form 6 columns L. Figure 3In this example, column L includes six pads 81 arranged in the Y direction from among multiple connection pads 81. Furthermore, the number of columns L containing connection pads 81 and the number of multiple connection pads 81 included in each column L are not limited to this example.

[0055] In each column L, multiple connection pads 81 are arranged at intervals in the Y direction. Furthermore, the multiple columns L of connection pads 81 are arranged at intervals in the X direction. The number of connection pads 81 in each column L corresponds, for example, to the function of the magnetic head 15.

[0056] like Figure 4 As shown, the connection pads 81 included in each column are sometimes referred to independently as connection pads 81A, 81B, 81C, 81D, 81E, and 81F. Through other means, multiple connection pads 81 may include multiple connection pads 81A, 81B, 81C, 81D, 81E, and 81F.

[0057] Connection pad 81B is an example of a write terminal. Connection pad 81E is an example of an HDI terminal. Connection pad 81F is an example of a first read terminal.

[0058] Multiple connection pads 81A, 81B, 81C, 81D, 81E, and 81F are arranged sequentially in the Y direction. Connection pad 81A is closer to the edge 61b of the joint 61 than the other multiple connection pads 81B, 81C, 81D, 81E, and 81F. Connection pad 81F is closer to the edge 61c of the joint 61 than the other multiple connection pads 81A, 81B, 81C, 81D, and 81E.

[0059] Multiple connection pads 81A are arranged at intervals in the X direction. Multiple connection pads 81B are separated from the multiple connection pads 81A in the -Y direction and are arranged at intervals in the X direction. Similarly, multiple connection pads 81C, 81D, 81E, and 81F are separated from adjacent multiple connection pads 81 in the -Y direction and are arranged at intervals in the X direction.

[0060] A connection pad 81A and its corresponding connection pads 81B, 81C, 81D, 81E, and 81F are positioned approximately in the same location in the X direction. However, the positions of the corresponding connection pads 81A, 81B, 81C, 81D, 81E, and 81F in the X direction can differ from each other. Furthermore, the number of connection pads 81 in each column L can also vary.

[0061] like Figure 5As shown, the multiple connection pads 81 of the FPC19 are respectively bonded to one of the multiple pads 55 of the flexible portion 43 via solder 87. The solder 87 is conductive and is an example of a bond. The solder 87 can be leaded solder or lead-free solder. The conductive adhesive is not limited to solder 87, and can be, for example, silver paste, solder, or conductive adhesive.

[0062] like Figure 3 As shown, the second mounting portion 52 of the flexible portion 43 extends transversely through the edge 61b of the joint portion 61 in the Y direction and covers the column L of the corresponding connecting pads 81. A plurality of pads 55 of a flexible portion 43 are connected to a plurality of connecting pads 81 included in a column L.

[0063] The preamplifier 44 is mounted on the surface 61a of the junction 61. Specifically, the electrodes of the preamplifier 44 are bonded to a plurality of mounting pads 82, for example, by solder. That is, the plurality of mounting pads 82 are connected to the preamplifier 44. Therefore, the plurality of connection pads 81 are located between the edge 61b and the preamplifier 44 in the direction along the surface 61a.

[0064] like Figure 4 As shown, multiple wirings 83 connect one of the multiple connection pads 81B, 81C, 81D, 81E, and 81F to one of the multiple mounting pads 82. Furthermore, the electrical path between the connection pads 81 and the mounting pads 82 may also include the wirings 83, the wiring included in the conductive layer 73, and the vias.

[0065] The preamplifier 44 is electrically connected to the magnetic head 15 via mounting pad 82, wiring 83, connecting pad 81, solder 87, pad 55, and wiring 56. On the other hand, multiple connecting pads 81A are connected to each other, for example, via other wiring 89, and are connected to the PCB, for example, via a driver mounted on the FPC 19.

[0066] The preamplifier 44 is electrically connected to the write element of the read / write head 15 via the connection pad 81B. That is, the connection pad 81B is assigned the electrical signal (write signal) of the information written by the read / write head 15 to the disk 12.

[0067] The preamplifier 44 amplifies the write signal output from the control device. The preamplifier 44 outputs the amplified write signal through the connection pad 81B to the write element of the read / write head 15. The write element writes information to the disk 12 based on the write signal. Thus, the write signal flows from the preamplifier 44 toward the read / write head 15 through the connection pad 81B.

[0068] The preamplifier 44 is electrically connected to the heater of the read / write head 15 via a connection pad 81C. The heater of the read / write head 15 adjusts the temperature of the read / write head 15, thereby adjusting the position of the write and read elements of the read / write head 15 relative to the disk 12.

[0069] The preamplifier 44 is electrically connected to the MAMR (microwave-assisted magnetic recording) element of the magnetic head 15 via a connection pad 81D. The MAMR element of the magnetic head 15 applies microwaves to the disk 12 by overlapping the recording magnetic field of the writing element.

[0070] The preamplifier 44 is electrically connected to the HDI sensor 45 built into the magnetic head 15 via the connecting pad 81E. That is, the connecting pad 81E is electrically connected to the HDI sensor 45. The HDI sensor 45 built into the magnetic head 15 is mounted on the flexible part 43.

[0071] The HDI sensor 45, for example, includes a thermocouple and outputs an electrical signal (detection signal) by detecting the contact between the disk 12 and the read / write head 15. For example, the resistance of the thermocouple changes due to the heat generated by the contact between the disk 12 and the read / write head 15. The HDI sensor 45 outputs a detection signal corresponding to the resistance value of the thermocouple. However, the HDI sensor 45 is not limited to this example. The detection signal is transmitted to the control device via the connection pad 81E and the preamplifier 44.

[0072] The preamplifier 44 is electrically connected to the read element of the magnetic head 15 via the connection pad 81F. That is, the connection pad 81F is assigned the electrical signal (read signal) of the information read by the magnetic head 15 from the disk 12.

[0073] The read element of the magnetic head 15 receives a read signal from the preamplifier 44 via the connection pad 81F. The preamplifier 44 amplifies the read signal and transmits it to the control device. Thus, the read signal flows from the magnetic head 15 toward the preamplifier 44 and through the connection pad 81F.

[0074] The control device is electrically connected to the GMA (Gimbal Micro Actuator) via connection pad 81A. That is, connection pad 81A is assigned to the GMA. The control device, for example, deforms the load beam 42 by driving the GMA and makes fine adjustments to the position of the magnetic head 15.

[0075] The planar ground layer 84 is a metal film extending along surface 61a. The planar ground layer 84 is set to ground potential. The planar ground layer 84 is separated from the connection pad 81, mounting pad 82, and wiring 83 in the direction along surface 61a. Alternatively, the planar ground layer 84 may also be connected to the connection pad 81, mounting pad 82, and wiring 83 that are assigned to ground.

[0076] The planar ground plane 84 is, for example, disposed between two adjacent columns L and in an area where no wiring 83 is provided. In other words, at least a portion of the planar ground plane 84 is located between two of the plurality of connection pads 81 in the direction along the surface 61a. Alternatively, the planar ground plane 84 may be disposed in other locations.

[0077] The planar ground layer 84 is closer to edge 61b than edge 61c of the joint 61. The planar ground layer 84 is separated from the protrusion 63. Alternatively, the planar ground layer 84 may be provided in a region closer to edge 61c than edge 61b, or it may be provided in the protrusion 63.

[0078] In the junction 61, the conductive layer 73 has a planar ground layer 91. The planar ground layer 91 is an example of a first planar ground layer. The planar ground layer 91 is a metal film extending along the surface 61a. The planar ground layer 91 is set to a ground potential.

[0079] The planar ground plane 91 covers multiple connection pads 81A, 81C, and 81D in the Z direction. In other words, the planar ground plane 91 overlaps with multiple connection pads 81A, 81C, and 81D in the Z direction.

[0080] Furthermore, the planar ground layer 91 covers the mounting pads 82 connected to the connection pads 81A, 81C, and 81D, as well as the wiring 83, in the Z direction. Additionally, the planar ground layer 91 covers the planar ground layer 84 in the Z direction. Thus, the planar ground layer 91 covers at least one of the plurality of connection pads 81, at least one of the plurality of mounting pads 82, and at least one of the plurality of wirings 83 in the Z direction.

[0081] In the Y direction, a portion of the planar ground layer 91 is located between the connecting pad 81A and the edge 61b of the junction 61. The end of the planar ground layer 91 in the +Y direction is located near edge 61b. Furthermore, in the Y direction, another portion of the planar ground layer 91 is located between the connecting pad 81F and the edge 61c of the junction 61. The end of the planar ground layer 91 in the -Y direction is located near edge 61c.

[0082] A plurality of holes 92, a plurality of first openings 93, and a plurality of second openings 94 are provided on the planar grounding layer 91. The holes 92, first openings 93, and second openings 94 are holes that penetrate the planar grounding layer 91 in the Z direction. Alternatively, the first openings 93 and second openings 94 may also be cuts.

[0083] The plurality of holes 92 includes a plurality of holes 92B and 92E. The plurality of holes 92B respectively overlap in the Z direction with at least a portion of a corresponding connection pad 81B, and at least a portion of a mounting pad 82 and a trace 83 connected to the connection pad 81B. In other words, the plurality of holes 92B each have a portion overlapping in the Z direction with at least a portion of a corresponding connection pad 81B, a portion overlapping in the Z direction with at least a portion of a mounting pad 82, and a portion overlapping in the Z direction with at least a portion of a trace 83.

[0084] Through other means, in the direction along surface 61a, at least a portion of the connection pad 81B, and at least a portion of the mounting pad 82 and wiring 83 connected to the connection pad 81B, are located inside the edge of the hole 92B. As described above, the planar ground layer 91 is separated from at least a portion of the connection pad 81B, and at least a portion of the mounting pad 82 and wiring 83 connected to the connection pad 81B, in the direction along surface 61a.

[0085] Multiple holes 92E overlap with at least a portion of the corresponding connection pad 81E and at least a portion of the mounting pad 82 and wiring 83 connected to the connection pad 81E in the Z direction. In other words, in the direction along the surface 61a, at least a portion of the connection pad 81E and at least a portion of the mounting pad 82 and wiring 83 connected to the connection pad 81E are located inside the edge of the hole 92E. Therefore, the planar ground layer 91 is separated from at least a portion of the connection pad 81E and at least a portion of the mounting pad 82 and wiring 83 connected to the connection pad 81E in the direction along the surface 61a.

[0086] Furthermore, the plurality of holes 92E overlap with at least a portion of the corresponding connection pad 81F and at least a portion of the mounting pad 82 and wiring 83 connected to the connection pad 81F in the Z direction. In other words, in the direction along the surface 61a, at least a portion of the connection pad 81F and at least a portion of the mounting pad 82 and wiring 83 connected to the connection pad 81F are located inside the edge of the hole 92E. Therefore, the planar ground layer 91 is separated from at least a portion of the connection pad 81F and at least a portion of the mounting pad 82 and wiring 83 connected to the connection pad 81F in the direction along the surface 61a.

[0087] The wiring 83 connected to the connection pad 81F is an example of a read wiring. The mounting pad 82 connected to the connection pad 81F via the wiring 83 is an example of a second read terminal. In addition, a hole different from the hole 92E may overlap in the Z direction with at least a portion of the corresponding connection pad 81F, and at least a portion of the mounting pad 82 and wiring 83 connected to the connection pad 81F.

[0088] Alternatively, a cutout or area divided into two parts between the planar ground layers 91 can be provided instead of a hole 92. This cutout or area also overlaps in the Z direction with at least a portion of the corresponding connection pad 81, and at least a portion of the mounting pad 82 and wiring 83 connected to the connection pad 81.

[0089] As described above, the planar ground layer 91 is at least partially separated from the defined wiring 83, the connection pads 81 (81B, 81E, 81F) connected to the defined wiring 83, and the mounting pads 82 in the direction along the surface 61a. Furthermore, the planar ground layer 91 is separated from at least a portion of each of the connection pads 81B, 81E, 81F in each of the plurality of columns L in the direction along the surface 61a. That is, in any column L, at least a portion of the connection pads 81B, 81E, 81F is not covered by the planar ground layer 91. Alternatively, the planar ground layer 91 may also cover at least one of the connection pads 81B, 81E, 81F in the plurality of columns L in the Z direction.

[0090] Furthermore, one of the plurality of connection pads 81 can be electrically connected to an HMAR (heat-assisted magnetic recording) element. A planar ground plane 91 covers this one of the plurality of connection pads 81 in the Z direction.

[0091] The first opening 93 is located between one of the plurality of connection pads 81 and the preamplifier 44 in the direction along the surface 61a. That is, an imaginary straight line connecting a point of one of the plurality of connection pads 81 and a point of the preamplifier 44 crosses the first opening 93 in the direction along the surface 61a.

[0092] The second opening 94 is located between the nearest through-hole 66 among the plurality of connection pads 81 and the through-hole 66 in the direction along the surface 61a. That is, an imaginary straight line connecting a point in one of the connection pads 81 closest to the through-hole 66 and a point in the through-hole 66 crosses the second opening 94 in the direction along the surface 61a.

[0093] The planar ground layer 91 is separated from the plurality of protrusions 63 in the direction along the surface 61a. Therefore, both the planar ground layers 84 and 91 are separated from the protrusions 63. Alternatively, the planar ground layer 91 may also be provided on the protrusions 63. Furthermore, conductors such as wiring 89 may also be provided on the protrusions 63.

[0094] The junction 61 also has a plurality of passages 99. The passages 99 are, for example, through-holes. The plurality of passages 99 respectively penetrate the base layer 71, connecting the planar ground layer 91 to a corresponding one of the plurality of planar ground layers 84.

[0095] During the assembly of HDD1 described above, the pads 55 of the flexible portion 43 are bonded to the connection pads 81 of the FPC19 via solder 87. For example, a paste containing solder 87 is applied to one of the pads 55 and the connection pads 81. Then, the second mounting portion 52 of the flexible portion 43 is overlapped with the joint portion 61 of the FPC19, and the paste is applied to the other of the pads 55 and the connection pads 81.

[0096] Next, for example, the laser passes through Figure 5 The paste is irradiated through the hole 43a in the flexible part 43. As a result, the paste melts, and the pad 55 and the connecting pad 81 are joined by solder 87.

[0097] When the laser irradiates the solder paste (solder 87), the paste is heated, and the area around the paste is also heated. For example, by transferring heat from the solder 87 to the connection pad 81, the portion around the connection pad 81 in the FPC 19 is heated.

[0098] In FPC19, the thermal conductivity of each of the conductive metal layers 72 and 73 is higher than that of either the base layer 71 or the capping layers 74 and 75. In other words, conductive layers 72 and 73 readily release heat. Therefore, in FPC19, the denser portions of conductive layers 72 and 73 readily release heat compared to the portions with lower density.

[0099] The density of wiring 83 increases around the preamplifier 44 in the junction 61 of FPC19. On the other hand, the density of wiring 83 decreases around the edge 61b in the junction 61. Therefore, more wiring 83 around the preamplifier 44 can dissipate heat.

[0100] Typically, around the edge 61b in the junction 61, where the density of the conductive layers 72 and 73 is low, the portion around the edge 61b becomes difficult to dissipate heat. Therefore, when irradiated with laser under the same conditions as the portion around the preamplifier 44, the portion around the edge 61b may be overheated. When the FPC 19 is overheated, for example, the conductive layers 72 and 73 may peel off from the base layer 71.

[0101] On the other hand, in this embodiment, planar ground layers 84 and 91 are provided around the edge 61b. For example, the planar ground layer 91 covers the connection pad 81A located near the edge 61b in the Z direction. As a result, the portion around the edge 61b also becomes easier to release heat, and the thermal conductivity of the portion around the edge 61b is more evenly distributed with that of the portion around the preamplifier 44. Therefore, even if the portion around the edge 61b is irradiated with laser under the same conditions as the portion around the preamplifier 44, it is possible to suppress overheating.

[0102] The first opening 93 extends through the planar ground layer 91, thereby preventing heat conduction across the first opening 93. The first opening 93 is located between the connection pad 81 and the preamplifier 44, thereby reducing heat conduction from around the connection pad 81 to around the preamplifier 44. Therefore, the first opening 93 can suppress the temperature rise around the connection pad 81F, which is closer to the preamplifier 44.

[0103] The second opening 94 penetrates the planar ground layer 91, thereby preventing heat conduction across the second opening 94. Furthermore, the screw 65 is made of metal and is larger than the conductive layers 72 and 73. Therefore, the area around the screw 65 easily releases heat. The second opening 94 is located between the connection pad 81 and the through-hole 66, thereby reducing heat conduction from around the connection pad 81 to around the screw 65. Thus, the second opening 94 can suppress the temperature rise around the connection pad 81F closest to the through-hole 66.

[0104] The multiple protrusions 63 have a large surface area per unit volume, making it easy to release heat. The planar grounding layers 84 and 91 are separated from the protrusions 63, thus suppressing the temperature rise around the multiple protrusions 63.

[0105] When the planar ground plane 91 covers the connection pads 81, mounting pads 82, and wiring 83 in the Z direction, parasitic capacitance may be generated, and impedance may be generated in the connection pads 81, mounting pads 82, and wiring 83. This impedance may affect the electrical signals flowing through the connection pads 81, mounting pads 82, and wiring 83.

[0106] On the other hand, in this embodiment, the planar ground layer 91 is separated from at least a portion of the connecting pads 81B, 81E, and 81F, and at least a portion of the corresponding mounting pads 82 and wiring 83 in the direction along surface 61a. That is, the planar ground layer 91 does not cover at least a portion of the conductors through which write signals, detection signals, and read signals flow.

[0107] The planar ground plane 91 does not cover the connection pad 81B and the corresponding mounting pad 82 and wiring 83, thus suppressing the influence of parasitic capacitance on the write signal. Similarly, the planar ground plane 91 does not cover the connection pad 81E and the corresponding mounting pad 82 and wiring 83, thus suppressing the influence of parasitic capacitance on the detection signal. Furthermore, the planar ground plane 91 does not cover the connection pad 81F and the corresponding mounting pad 82 and wiring 83, thus suppressing the influence of parasitic capacitance on the read signal.

[0108] Alternatively, the planar ground plane 91 can also cover the entirety of the connection pads 81B and 81E, as well as the corresponding mounting pads 82 and wiring 83, in the Z direction. For example, when the impedance has a relatively small impact on the write signal and the detection signal, the planar ground plane 91 covering the entirety of the connection pads 81B and 81E, as well as the corresponding mounting pads 82 and wiring 83, in the Z direction facilitates heat dissipation.

[0109] In this embodiment, the planar ground layer 91 is completely separated from the wiring 83 connected to the connection pad 81F in the direction along the surface 61a. On the other hand, the planar ground layer 91 may cover a portion of the wiring 83 connected to the connection pads 81B and 81E in the Z direction. For example, the portion of the planar ground layer 91 that connects one part to another may extend in a manner that traverses a portion of the wiring 83 connected to the connection pad 81B. Thus, the planar ground layer 91 can suppress the occurrence of a potential difference between one part and another of the planar ground layer 91.

[0110] In the HDD1 of this embodiment described above, the FPC19 has a surface 61a, a plurality of connection pads 81 disposed on the surface 61a, and a planar ground layer 91. The plurality of connection pads 81 are respectively bonded to a corresponding one of the plurality of pads 55 by solder 87. The planar ground layer 91 covers at least one of the plurality of connection pads 81 in a Z direction orthogonal to the surface 61a. Therefore, when the connection pads 81 are bonded to the pads 55 by solder 87, the planar ground layer 91 allows heat transferred from the solder 87 heated by a heat source such as a laser to the connection pads 81 to be released. Thus, the HDD1 can suppress the FPC19 from peeling due to overheating of the connection pads 81. Furthermore, the plurality of connection pads 81 includes connection pads 81F. An electrical signal (read signal) for information read from the disk 12 by the read head 15 flows in the connection pads 81F. The planar ground layer 91 separates from at least a portion of the connection pads 81F in a direction along the surface 61a. Normally, when a planar ground plane is close to a conductor such as a terminal or wiring of a flowing electrical signal, impedance is generated in that conductor, affecting the electrical signal. When impedance is generated in the connection pad 81F of the flowing read signal, this impedance may affect the reading and writing of information in the HDD1. On the other hand, even if impedance is generated in the connection pads 81C and 81D, the impact on the reading and writing of information in the HDD1 is relatively small. In the HDD1 of this embodiment, since the planar ground plane 91 is separated from the connection pad 81F, the generation of impedance in the connection pad 81F due to its proximity to the planar ground plane 91 can be suppressed. Therefore, the HDD1 can suppress the peeling of the FPC 19 through the planar ground plane 91, and can suppress the influence of the planar ground plane 91 on the read signal, thereby suppressing the performance degradation of the HDD1.

[0111] Furthermore, in the HDD1 of this embodiment described above, the FPC19 has a surface 61a, a plurality of connection pads 81 disposed on the surface 61a, a plurality of mounting pads 82 disposed on the surface 61a, a plurality of wirings 83, and a planar ground layer 91. The plurality of connection pads 81 are respectively bonded to a corresponding one of the plurality of pads 55 by solder 87. The plurality of wirings 83 connect the plurality of connection pads 81 to the plurality of mounting pads 82. The planar ground layer 91 covers at least one of the plurality of connection pads 81, at least one of the plurality of mounting pads 82, and at least one of the plurality of wirings 83 in a Z direction orthogonal to the surface 61a. Therefore, when the connection pads 81 are bonded to the pads 55 by solder 87, the planar ground layer 91 allows heat transferred from the solder 87 heated by a heat source such as a laser to the connection pads 81 to be released. Thus, the HDD1 can suppress the FPC19 from peeling due to overheating of the connection pads 81. Furthermore, the preamplifier 44 is connected to a plurality of mounting pads 82. The planar ground layer 91 is at least partially separated from one of the plurality of wirings 83, one of the plurality of connection pads 81 connected to that wiring 83, and one of the plurality of mounting pads 82 in the direction along the surface 61a. In this embodiment, the HDD1 is separated from the interconnected connection pads 81, mounting pads 82, and wirings 83 by the planar ground layer 91, thereby suppressing the generation of impedance in these connection pads 81, mounting pads 82, and wirings 83. Therefore, the HDD1 can suppress the peeling of the FPC 19 by the planar ground layer 91, and can suppress the influence of the planar ground layer 91 on the electrical signals flowing in the connection pads 81, mounting pads 82, and wirings 83, thereby suppressing the performance degradation of the HDD1.

[0112] The electrical signal (write signal) for the information written by the read / write head 15 to the disk 12 flows through the connection pad 81B. The planar ground layer 91 is separated from the connection pad 81B in the direction along the surface 61a. Since the HDD1 is separated from the connection pad 81B by the planar ground layer 91, impedance generated in the connection pad 81B due to its proximity to the planar ground layer 91 can be suppressed. Therefore, the HDD1 can suppress the peeling of the FPC 19 by the planar ground layer 91, and can suppress the influence of the planar ground layer 91 on the write signal, thereby suppressing the performance degradation of the HDD1.

[0113] HDI sensor 45 is mounted on flexible part 43 and outputs an electrical signal (detection signal) by detecting the contact between disk 12 and read / write head 15. Connecting pad 81E is electrically connected to HDI sensor 45. Planar ground layer 91 is separated from connecting pad 81E in the direction along surface 61a. HDD1 is separated from connecting pad 81E by planar ground layer 91, thereby suppressing impedance generated in connecting pad 81E due to proximity between connecting pad 81E and planar ground layer 91. Therefore, HDD1 suppresses FPC 19 peeling by planar ground layer 91 and suppresses the influence of planar ground layer 91 on the detection signal, thereby suppressing performance degradation of HDD1.

[0114] Multiple connection pads 81 form multiple columns L. Each column L includes two or more of the multiple connection pads 81 arranged in the Y direction along the surface 61a. Each column L includes a connection pad 81F. A planar ground layer 91 is separated from at least a portion of the respective connection pads 81F of the multiple columns L in the direction along the surface 61a. Therefore, the planar ground layer 91 is able to suppress impedance generation in the respective connection pads 81F of the multiple columns L.

[0115] The FPC19 has a mounting pad 82 connected to the preamplifier 44 and wiring 83 connecting the connection pad 81F to the mounting pad 82. A planar ground layer 91 is separated from at least a portion of the mounting pad 82 and wiring 83 in a direction along the surface 61a. Therefore, the HDD1 of this embodiment can suppress the generation of impedance in the connection pad 81F, wiring 83, and mounting pad 82 due to their proximity to the planar ground layer 91. Thus, the HDD1 can more effectively suppress the influence of the planar ground layer 91 on the read signal, thereby suppressing performance degradation of the HDD1.

[0116] A hole 92 is provided on the planar ground layer 91. At least a portion of the connection pad 81F, wiring 83, and mounting pad 82 are located inside the edge of the hole 92 in the direction along the surface 61a. That is, the planar ground layer 91 exists around the connection pad 81F, wiring 83, and mounting pad 82. Therefore, when the connection pad 81 is engaged with the pad 55, the planar ground layer 91 can more effectively dissipate heat. Thus, the HDD1 can suppress the FPC19 from peeling off due to overheating of the connection pad 81.

[0117] A first opening 93 is provided on the planar ground layer 91. The first opening 93 is located between one of the plurality of connection pads 81 and the preamplifier 44 in the direction along the surface 61a. The first opening 93 can reduce the heat conducted through the planar ground layer 91 between the connection pads 81 and the preamplifier 44. Therefore, in this embodiment, the HDD1 can reduce the temperature imbalance among the plurality of connection pads 81 when the connection pads 81 are bonded to the pads 55. Thus, the HDD1 can suppress the FPC 19 from peeling off due to overheating of some connection pads 81.

[0118] The FPC19 has an edge 61b extending in the X direction along the surface 61a, and a protrusion 63 protruding from the edge 61b in the Y direction along the surface 61a and intersecting the X direction. A plurality of connection pads 81 are located between the edge 61b and the preamplifier 44 in the direction along the surface 61a. A planar ground layer 91 is separated from the protrusion 63 in the direction along the surface 61a. Compared to the joint 61 in the FPC19 that includes the edge 61b, the protrusion 63 protruding from the edge 61b is more prone to heat dissipation. The planar ground layer 91 is separated from the protrusion 63, thus suppressing excessive heat dissipation from the protrusion 63. Therefore, the HDD1 of this embodiment can reduce temperature imbalance in the FPC19 when the connection pads 81 are bonded to the pads 55. Therefore, the HDD1 can suppress the FPC19 from peeling due to overheating of a portion of the connection pads 81.

[0119] The FPC19 has a base layer 71 and a conductive layer 72 stacked on the base layer 71. The conductive layer 72 has a plurality of connection pads 81 and a planar ground layer 84 separated from the plurality of connection pads 81 in a direction along the surface 61a. At least a portion of the planar ground layer 84 is located between two of the plurality of connection pads 81 in the direction along the surface 61a. That is, the planar ground layer 84 is disposed near the plurality of connection pads 81. Thus, when the connection pads 81 are bonded to the pads 55, the planar ground layer 84 can dissipate heat from the connection pads 81. Therefore, the HDD1 can suppress the FPC19 from peeling off due to overheating of the connection pads 81.

[0120] FPC19 has a path 99 connecting planar ground plane 91 and planar ground plane 84. Therefore, HDD1 in this embodiment can make planar ground plane 91 and planar ground plane 84 at the same potential. Thus, HDD1 can suppress the planar ground plane 91 and planar ground plane 84 from functioning as antennas, generating unwanted impedance, or generating noise, thereby suppressing performance degradation of HDD1.

[0121] An insertion hole 66 for a screw 65 to pass through is provided on the FPC 19. A second opening 94 is provided on the planar ground layer 91. The second opening 94 is located between the one of the plurality of connection pads 81 closest to the insertion hole 66 and the insertion hole 66 in the direction along the surface 61a. The second opening 94 can reduce the heat conducted through the planar ground layer 91 between the connection pad 81 and the screw 65 passing through the insertion hole 66. Thus, the HDD 1 of this embodiment can reduce the temperature imbalance among the plurality of connection pads 81 when the connection pads 81 are bonded to the pads 55. Therefore, the HDD 1 can suppress the FPC 19 from peeling off due to overheating of some connection pads 81.

[0122] In the above explanation, 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.

[0123] Some 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 new 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 as described in the claims and its equivalents.

Claims

1. A disk device, comprising: a magnetic disk; a head configured to read and write information from and to the magnetic disk; a first flexible printed circuit board having a plurality of first terminals, the head being mounted to the first flexible printed circuit board, at least one of the plurality of first terminals being electrically connected to the head; and a first planar ground layer covering at least one of the plurality of second terminals in a direction orthogonal to the surface; and a preamplifier mounted to the second flexible printed circuit board, the preamplifier outputting an electrical signal of information written from the head to the magnetic disk to the head and inputting an electrical signal of information read from the magnetic disk by the head from the head, the plurality of second terminals including a first read terminal through which the electrical signal of information read from the magnetic disk by the head flows, the first planar ground layer being separated from at least a portion of the first read terminal in a direction along the surface, a first opening portion being provided in the first planar ground layer, the first opening portion being located between one of the plurality of second terminals and the preamplifier in a direction along the surface, the second flexible printed circuit board having a second read terminal connected to the preamplifier and a read wiring connecting the first read terminal and the second read terminal, the first planar ground layer being separated from at least a portion of the second read terminal and the read wiring in a direction along the surface, the first planar ground layer covering the second read terminal and the read wiring in a direction orthogonal to the surface.

2. The disk device according to claim 1, wherein the first planar ground layer covers two or more of the plurality of second terminals in a direction orthogonal to the surface.

3. The disk device according to claim 1, wherein the plurality of second terminals include a write terminal through which an electrical signal of information written to the magnetic disk by the head flows, the first planar ground layer being separated from the write terminal in a direction along the surface.

4. The disk device according to claim 1, further comprising an HDI sensor that outputs an electrical signal in response to contact between the magnetic disk and the head, the plurality of second terminals including an HDI terminal electrically connected to the HDI sensor, the first planar ground layer being separated from the HDI terminal in a direction along the surface. A second flexible printed circuit board has a surface, a plurality of second terminals disposed on the surface and respectively joined to corresponding ones of the first terminals by conductive joining bodies.

5. The disk device according to claim 1, wherein the plurality of second terminals form a plurality of columns each including two or more of the plurality of second terminals arranged in a first direction along the surface, the plurality of columns each including the first read terminal, the first planar ground layer being separated from at least a portion of the first read terminal of each of the plurality of columns in a direction along the surface.

6. The disk device according to claim 1, wherein a hole is provided in the first planar ground layer, at least a portion of the first read terminal, the read wiring, and the second read terminal being located inside an edge of the hole in a direction along the surface.

7. A disk device, comprising: a magnetic disk; a head configured to read and write information from and to the magnetic disk; ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ a first flexible printed circuit board having a plurality of first terminals on which the magnetic head is mounted, at least one of the plurality of first terminals being electrically connected to the magnetic head; a second flexible printed circuit board having a surface, a plurality of second terminals provided on the surface and respectively joined to corresponding ones of the plurality of first terminals by electrically conductive joining bodies, a plurality of third terminals provided on the surface, a plurality of wirings connecting the plurality of second terminals to the plurality of third terminals, and a first planar ground layer covering at least one of the plurality of second terminals, at least one of the plurality of third terminals, and at least one of the plurality of wirings in a direction orthogonal to the surface, and a preamplifier connected to the plurality of third terminals, which outputs an electrical signal of information written to the magnetic head by the magnetic head to the magnetic head and inputs an electrical signal of information read from the magnetic disk by the magnetic head from the magnetic head, the first planar ground layer is at least partially separated from one of the plurality of wirings, one of the plurality of second terminals connected to the one of the plurality of wirings, and one of the plurality of third terminals in a direction along the surface, a first opening portion is provided in the first planar ground layer, which is located between the one of the plurality of second terminals and the preamplifier in the direction along the surface.

8. The disk device according to claim 7, wherein the first planar ground layer covers two or more of the plurality of second terminals, two or more of the plurality of third terminals, and two or more of the plurality of wirings in the direction orthogonal to the surface.

9. The disk device according to any one of claims 1 to 8, wherein the second flexible printed circuit board has an edge extending in a second direction along the surface, and a protruding portion protruding from the edge in a third direction along the surface and intersecting the second direction, the plurality of second terminals are located between the edge and the preamplifier in the direction along the surface, the first planar ground layer is separated from the protruding portion in the direction along the surface.

10. The disk device according to any one of claims 1 to 8, wherein the second flexible printed circuit board has a base layer and an electrically conductive layer laminated to the base layer, the electrically conductive layer has the plurality of second terminals and a second planar ground layer separated from the plurality of second terminals in the direction along the surface, at least a portion of the second planar ground layer is located between two of the plurality of second terminals in the direction along the surface, the first planar ground layer covers the second planar ground layer in the direction orthogonal to the surface.

11. The disk device according to claim 10, wherein the second flexible printed circuit board has a via connecting the first planar ground layer to the second planar ground layer.

12. The disk device according to any one of claims 1 to 8, wherein a through-hole is provided in the second flexible printed circuit board through which a screw passes, A second opening portion is provided on the first plane ground layer, and is located between one of the second terminals closest to the insertion hole and the insertion hole in a direction along the surface.

Images