Patent Publication Number: US-11646056-B2

Title: Disk device with improved connectivity

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a divisional of U.S. application Ser. No. 16/804,384 filed on Feb. 28, 2020 and is based upon and claims the benefit of priority from Japanese Patent Application No. 2019-170065, filed on Sep. 19, 2019; the entire contents of which are incorporated herein by reference. 
    
    
     FIELD 
     Embodiments described herein relate generally to a disk device. 
     BACKGROUND 
     Disk devices such as a hard disk drive (HDD) typically include a magnetic disk and a magnetic head that reads/writes information from/to the magnetic disk. For example, a flexure and a flexible printed circuit board (FPC) serve to electrically connect between a control device for controlling the HDD, and the magnetic head. Terminals of the flexure and terminals of the FPC are interconnected by means of soldering, for example. 
     Such disk devices may vary in quality depending on the temperature of the solder or the vicinity of the solder at the time of connecting the terminals with the solder. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is an exemplary schematic perspective view of an HDD according to a first embodiment; 
         FIG.  2    is an exemplary view schematically illustrating an FPC and flexures according to the first embodiment; 
         FIG.  3    is an exemplary plan view schematically illustrating part of the FPC and part of the flexures according to the first embodiment; 
         FIG.  4    is an exemplary schematic plan view of part of a joint according to the first embodiment; 
         FIG.  5    is an exemplary plan view schematically illustrating part of the FPC according to the first embodiment; and 
         FIG.  6    is an exemplary plan view schematically illustrating part of the FPC according to a second embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     A disk device according to one embodiment includes a recording medium, a magnetic head, a wiring member, and a flexible printed circuit board. The magnetic head is configured to read and write information from and to the recording medium. The wiring member includes a plurality of first terminals, and a plurality of first wires that electrically connect the magnetic head and the plurality of first terminals. The flexible printed circuit board includes a surface, a plurality of second terminals located on the surface to be connected to the plurality of first terminals by means of a conductive adhesive, and a ground plane spaced apart from the plurality of second terminals in a direction along the surface. 
     First Embodiment 
     A first embodiment will be described below with reference to  FIGS.  1  to  5   . In the present specification, constituent elements according to the present embodiment and descriptions of these elements may be represented in multiple forms. The constituent elements and their descriptions are merely exemplary and are not intended to limit the scope of the invention by the descriptions. The constituent elements may be specified by names that differ from those in the present specification. Furthermore, the constituent elements may be represented in a different manner from the present specification. 
       FIG.  1    is an exemplary schematic perspective view of a hard disk drive (HDD)  1  according to the first embodiment. An HDD  1  is an example of a disk device. The disk device is not limited to the HDD  1  and may be another disk device such as a hybrid hard disk drive. 
     As illustrated in  FIG.  1   , the HDD  1  includes an housing  11 , a plurality of magnetic disks  12 , a spindle motor  13 , a clamping spring  14 , a plurality of magnetic heads  15 , an actuator assembly  16 , a voice coil motor  17 , a ramp-load mechanism  18 , and a flexible printed circuit board (FPC)  19 . The magnetic disk  12  is an example of a recording medium. 
     The housing  11  includes a bottom wall  11   a  of a plate shape and sidewalls  11   b  that protrude from the bottom wall  11   a . The housing  11  also includes a cover attached to the sidewalls  11   b  and covering the interior of the housing  11 . The housing  11  houses at least part of the magnetic disks  12 , the spindle motor  13 , the clamping spring  14 , the magnetic heads  15 , the actuator assembly  16 , the voice coil motor  17 , the ramp-load mechanism  18 , and the FPC  19 . 
     The magnetic disk  12  is, for example, a disk including a magnetic recording layer on at least one of an upper surface and a lower surface. The diameter of the magnetic disk  12  is set to 3.5 inches, for example, but it is not limited to this example. 
     The spindle motor  13  supports and rotates a plurality of magnetic disks  12  placed on the top of each other with spacing. The clamping spring  14  holds the magnetic disks  12  in the hub of the spindle motor  13 . 
     The magnetic heads  15  record and reproduce information on and from the recording layers of the magnetic disks  12 . In other words, the magnetic heads  15  read/write information from/to the magnetic disks  12 . The magnetic heads  15  are supported by the actuator assembly  16 . 
     The actuator assembly  16  is rotatably supported by a support shaft  21  spaced apart from the magnetic disks  12 . The voice coil motor  17  rotates the actuator assembly  16  to a desired position. Along with the rotation of the actuator assembly  16  by the voice coil motor  17 , the magnetic heads  15  move to the outermost circumference of the magnetic disks  12 , and the ramp-load mechanism  18  holds the magnetic heads  15  in an unload position spaced apart from the magnetic disks  12 . 
     A printed circuit board is attached to the outside of the bottom wall  11   a  of the housing  11 . A control device that controls the spindle motor  13 , the magnetic heads  15 , and the voice coil motor  17  is mounted on the printed circuit board. The control device is electrically connected to the magnetic heads  15  and the voice coil motor  17  via the FPC  19 . 
     The actuator assembly  16  includes an actuator block  31 , a plurality of arms  32 , and a plurality of head suspension assemblies  33 . The head suspension assemblies  33  can also be referred to as head gimbal assemblies (HGA). 
     The actuator block  31  is rotatably supported by a support shaft  21  via a bearing, for example. The arms  32  protrude from the actuator block  31  in a direction substantially orthogonal to the support shaft  21 . The actuator assembly  16  may be divided into a plurality of actuator blocks  31  so that the arms  32  protrude from the respective actuator blocks  31 . 
     The arms  32  are disposed at intervals along the support shaft  21 . The arms  32  have a plate shape to be insertable into two adjacent magnetic disks  12 . The arms  32  extend substantially in parallel. 
     The actuator block  31  and the arms  32  are integrally formed from aluminum, for example. The materials of the actuator block  31  and the arms  32  are not limited to this example. 
     The voice coil of the voice coil motor  17  is placed on a projection that protrudes from the actuator block  31 . The voice coil motor  17  includes a pair of yokes, a voice coil disposed between the yokes, and a magnet located on the yokes. 
     The head suspension assemblies  33  are attached to the tips of the corresponding arms  32  and protrude from the arms  32 . As a result, the head suspension assemblies  33  are disposed at intervals along the support shaft  21 . 
       FIG.  2    is an exemplary view schematically illustrating the FPC  19  and flexure  43  according to the first embodiment. The head suspension assemblies  33  each include a base plate  41  and a loading beam  42 , which are illustrated in  FIG.  1   , and the flexure  43  illustrated in  FIG.  2   . The flexure  43  is an example of a wiring member. In addition, the magnetic heads  15  are attached to the head suspension assemblies  33 . 
     The base plate  41  and the loading beam  42  are made of stainless steel, for example. The materials of the base plate  41  and the loading beam  42  are not limited to this example. The base plate  41  has a plate shape and is attached to the tips of the arms  32 . The loading beam  42  has a thinner plate shape than the base plate  41 . The loading beam  42  is attached to the tip of the base plate  41  and protrudes from the base plate  41 . 
     As illustrated in  FIG.  2   , the flexure  43  has a long and narrow belt shape. The shape of the flexure  43  is not limited to this example. The flexure  43  is a multilayered plate including a metal sheet (backing layer) as stainless steel, an insulating layer formed on the metal sheet, a conductive layer constituting a plurality of wires (wiring patterns) on the insulating layer, and a protective layer (insulating layer) covering the conductive layer. The flexure  43  includes a first attachment  51 , a second attachment  52 , and a middle part  53 . 
     The first attachment  51  is provided at one end of the flexure  43 . The second attachment  52  is provided at the other end of the flexure  43 . The middle part  53  extends between the first attachment  51  and the second attachment  52 . 
     The first attachment  51  is attached to the base plate  41  and the loading beam  42 . The first attachment  51  is located above the loading beam  42  and includes a displaceable gimbal (elastic support). The magnetic heads  15  are mounted on the gimbal. 
     The middle part  53  overhangs from the first attachment  51  to outside the side edge of the base plate  41 . The middle part  53  extends toward the actuator block  31  along the side edges of the arms  32  outside the base plate  41 . 
     The second attachment  52  has a rectangular shape, extending in the longitudinal direction of the middle part  53 . The second attachment  52  is bent substantially orthogonal to the middle part  53 . The second attachment  52  is equipped with a plurality of pads  55 . The pads  55  are an example of first terminals. The pads  55  are arranged at intervals in the longitudinal direction of the second attachment  52 . 
     Each flexure  43  further includes a plurality of wires  56 . The wires  56  are an example of first wires. The wires  56  are laid on a conductive layer of the flexure  43 . The wires  56  extend between the first attachment  51  and the second attachment  52  through the middle part  53 . The wires  56  serve to electrically connect between the pads  55 , and the read elements and write elements of the magnetic head  15  and a heater or another component. In other words, the wires  56  extend between the pads  55  and the electrodes connected to the magnetic heads  15 , and serves as at least part of the electrical paths between the pads  55  and the magnetic heads  15 . 
       FIG.  3    is an exemplary plan view schematically illustrating part of the FPC  19  and part of the flexures  43  according to the first embodiment. As illustrated in  FIG.  3   , the FPC  19  includes a joint  61  and an extension  62 . The joint  61  is attached to the actuator block  31 , for example. The extension  62  extends between the joint  61  and a printed circuit board on which the control device is mounted. 
     The second attachments  52  of the flexures  43  are attached to the joint  61  of the FPC  19 . The FPC  19  electrically connects the printed circuit board on which the control device is mounted, and the flexures  43 . In other words, the control device is electrically connected to the magnetic heads  15  via the printed circuit board, the FPC  19 , and the flexures  43 . 
       FIG.  4    is an exemplary schematic plan view of part of the joint  61  according to the first embodiment. The FPC  19  includes, for example, a first insulating layer, a first conductive layer  19   a  formed on the first insulating layer, a base layer  19   b  formed on the first conductive layer  19   a , a second conductive layer  19   c  formed on the base layer  19   b , and a second insulating layer  19   d  formed on the second conductive layer  19   c . The layers of the FPC  19  are not limited to this example and may have fewer or more layers. In  FIG.  4    the first conductive layer  19   a  is represented by broken lines, the base layer  19   b  and the second conductive layer  19   c  are represented by solid lines, and the second insulating layer  19   d  are represented by dash-dot-dot lines. 
     The first conductive layer  19   a  and the second conductive layer  19   c  are made from a conductor such as metal. The first insulating layer, the base layer  19   b , and the second insulating layer  19   d  are made from an insulator such as synthetic resin. For example, the first insulating layer, the base layer  19   b  and the second insulating layer  19   d  are made from polyimide. In addition, the FPC  19  includes an adhesive layer between every two layers. 
     In the joint  61 , a metal sheet (backing layer) as aluminum is attached to the first insulating layer of the FPC  19 . Consequently, the joint  61  is substantially flat. The joint  61  is attached to the actuator block  31  via the metal sheet. As illustrated in  FIG.  1   , the extension  62  is bent between the joint  61  and the circuit board to be able to absorb the displacement of the joint  61  occurring due to the rotation of the actuator assembly  16 . 
     As illustrated in  FIG.  3   , the joint  61  of the FPC  19  includes a surface  71 , an edge  72 , and a plurality of pads  73 . The pads  73  are an example of second terminals. The surface  71  of the FPC  19  is formed by, for example, the second insulating layer  19   d , and the base layer  19   b  and the second conductive layer  19   c  exposed from holes in the second insulating layer  19   d . The surface  71  may also be formed of other parts. 
     As illustrated in the drawings including  FIG.  3   , in the present specification, an X-axis, Y-axis and Z-axis are defined for the sake of expediency on the premise that the surface  71  be flat. The X-axis, Y-axis, and Z-axis are orthogonal to one another. The X-axis is along the width of the surface  71 . The Y-axis is along the length of the surface  71 . The Z-axis is orthogonal to the surface  71 . 
     In addition, in the present specification, an X direction, Y direction, and Z direction are defined. The X direction is a direction along the X-axis and includes a +X direction indicated by an X-axis arrow and a −X direction which is the opposite direction of the X-axis arrow. The Y direction is a direction along the Y-axis and includes a +Y direction indicated by a Y-axis arrow and a −Y direction which is the opposite direction of the Y-axis arrow. The Z direction is a direction along the Z-axis and includes a +Z direction indicated by a Z-axis arrow and a −Z direction which is the opposite direction of the Z-axis arrow. 
     The X direction and Y direction are along the surface  71 . The X direction and Y direction intersect each other (orthogonal in the present embodiment). The Z direction is orthogonal to the surface  71 . The Y direction is an example of a first direction. The X direction is an example of a second direction. 
     The joint  61  may also be bent such that the surface  71  is curved or uneven. In this case, the X direction is along the width of the joint  61 , and the Y direction is along the length of the joint  61  along the surface  71 . 
     The edge  72  is connected to the end of the surface  71  and faces in a direction substantially orthogonal to the surface  71 . The edge  72  includes one edge  72   a  of the joint  61  and another edge  72   b  of the joint  61 . The edge  72   a  extends the +Y directional end of the joint  61 . The edge  72   b  is the −Y directional end of the joint  61 . The extension  62  extends from the edge  72   b  of the joint  61 . 
     The pads  73  are mounted on the surface  71 . More specifically, as illustrated in  FIG.  4   , the pads  73  are located on the second conductive layer  19   c . The second insulating layer  19   d  is provided with a plurality of holes  75 . The pads  73  are exposed from the holes  75  to the outside of the FPC  19 . Thus, the pads  73  are located on the outer face (surface  71 ) of the FPC  19 . 
     In the example of  FIG.  3   , the pads  73  are arrayed in six rows in the Y direction. In the following each row of the pads  73  may be individually referred to as the pads  73 A,  73 B,  73 C,  73 D,  73 E, and  73 F. In other words, the pads  73  include the pads  73 A,  73 B,  73 C,  73 D,  73 E, and  73 F. The pad  73 A is an example of a first electrode. The pad  73 B is an example of a second electrode. The number of rows of the pads  73  corresponds to the number of magnetic disks  12 . For example, in the case of the HDD  1  including nine magnetic disks  12 , the pads  73  are arranged in nine rows. 
     In each of the rows, the pads  73  are arranged at intervals in the Y direction. The rows of the pads  73  are arranged at intervals in the X direction. In the example of  FIG.  3   , each row includes six pads  73 . The number of the pads  73  in each row corresponds to the number of the functions of the magnetic heads  15 , for example. 
     The pads  73 A,  73 B,  73 C,  73 D,  73 E, and  73 F are arranged in order in the X direction. The pads  73 A are arranged at intervals in the Y direction. The pads  73 B are arranged at intervals in the Y direction with spacing from the pads  73 A in the +X direction (X direction). Likewise, the pads  73 C,  73 D,  73 E, and  73 F are arranged at intervals in the Y direction with spacing from the pads  73  in the preceding row in the +X direction. 
     The pads  73 A and their corresponding pads  73 B,  73 C,  73 D,  73 E, and  73 F are disposed in substantially the same positions in the Y direction. The corresponding pads  73 A,  73 B,  73 C,  73 D,  73 E, and  73 F may differ in position from one another in the Y direction. The numbers of pads  73  in each row may also differ. 
     The pads  73 A and  73 B among the pads  73  will be described below in detail as representative examples. In the following, the pad  73 A may be replaced with the pad  73 C or the pad  73 E, and pad  73 B may be replaced with the pad  73 D or the pad  73 F. 
     The pads  73  of the FPC  19  are connected to the pads  55  of the flexures  43  with solder  77 . The solder  77  is an example of a conductive adhesive. The solder  77  includes a leaded solder or a lead-free solder. The conductive adhesive is not limited to the solder  77  and may be silver paste or wax, for example. 
     The second attachment  52  of the flexure  43  extends in the Y direction, crossing the edge  72   a  of the joint  61  to cover the corresponding rows of pads  73 . The pads  55  of one flexure  43  are connected to the pads  73  in one row. For example, the pads  55  of one flexure  43  are connected to the pads  73 A, and the pads  55  of another flexure  43  are connected to the pads  73 B. 
     The joint  61  includes a joint part  61   a  and a mount  61   b . In  FIG.  3   , the joint part  61   a  and the mount  61   b  are sectioned by a dash-dot-dot line. The joint part  61   a  is an example of a first part. The mount  61   b  is an example of a second part. The joint part  61   a  and the mount  61   b  are both part of the joint  61 . 
     The joint part  61   a  is closer to the edge  72   a  of the joint  61  than the mount  61   b . The pads  73  are located on the joint part  61   a  with spacing from the mount  61   b . The mount  61   b  is closer to the edge  72   b  of the joint  61  than the joint part  61   a.    
     Two preamplifiers  81  are mounted on the surface  71  of the joint  61 . The preamplifiers  81  are an example of an electronic component and a component. The preamplifier  81  may also be referred to as a head integrated circuit (IC) or a head amplifier. 
     The preamplifiers  81  are mounted on the mount  61   b  of the joint  61 . For example, the terminals of the preamplifiers  81  are connected to the terminals on the surface  71  of the mount  61   b . The two preamplifiers  81  are arranged at an interval in the X direction. 
     As illustrated in  FIG.  4   , the joint part  61   a  includes an inner part  61   aa  between the rows and two outer parts  61   ab  outside the rows. The inner part  61   aa  is an example of a third part. The outer parts  61   ab  are an example of a fourth part. The inner part  61   aa  and the outer parts  61   ab  are both part of the joint part  61   a.    
     The inner part  61   aa  is located between the pads  73 A and the pads  73 B in the X direction. The inner part  61   aa  extends in the Y direction along the pads  73 A and  73 B. 
     The outer parts  61   ab  are spaced further from the inner part  61   aa  than the pads  73 A and  73 B in the X direction. For example, one outer part  61   ab  is located between the pads  73 A and the edge  72  of the joint  61 . The other outer part  61   ab  is located between the pads  73 B and the pads  73 C. The outer parts  61   ab  extend in the Y direction along the pads  73 A and  73 B. 
       FIG.  5    is an exemplary plan view schematically illustrating part of the FPC  19  according to the first embodiment.  FIG.  5    omits depicting the second insulating layer  19   d . As illustrated in  FIG.  5   , the FPC  19  includes a plurality of wires  83  that electrically connects the preamplifiers  81  and the plurality of pads  73 , and wires  84  that electrically connect the preamplifiers  81  and the circuit board on which the control device is mounted. 
     As illustrated in  FIG.  4   , the wires  83  include a plurality of via holes  83   a , a plurality of first wires  83   b , a plurality of second wires  83   c , and a plurality of third wires  83   d . The first wires  83   b  are an example of second wires. The second wires  83   c  are an example of third wires. 
     The via holes  83   a  include through-connections, plated through-holes, and other types of via holes, for example. The via holes  83   a  penetrate the base layer  19   b  and electrically connect the first conductive layer  19   a  and the second conductive layer  19   c . The via holes  83   a  may also penetrate multiple layers. 
     At least one of the via holes  83   a  is located in the inner part  61   aa  of the joint part  61   a . At least one of the via holes  83   a  in the inner part  61   aa  is located in the middle of two adjacent pads among the pads  73 A in the Y direction. More specifically, the via holes  83   a  may be partially located in the middle of two adjacent pads among the pads  73 A in the Y direction. That is, the cores of the via holes  83   a  may be apart from the middle of two adjacent pads among the pads  73 A in the Y direction. The via holes  83   a  in the outer parts  61   ab  may be located in the middle of two adjacent pads among the pads  73 A in the Y direction. 
     As described above, at least one of the via holes  83   a  is located in the middle of two adjacent ones of the pads  73 A in the Y direction. The via hole  83   a  may also be located in a region between the two adjacent pads  73 A in the Y direction, or may be spaced apart in the X direction from the region between the two adjacent pads  73 A in the Y direction. In the present embodiment, the via hole  83   a  is located in the inner part  61   aa  with spacing in the X direction from the region between the two adjacent pads  73 A in the Y direction. 
     At least one of the via holes  83   a  in the inner part  61   aa  is located in the middle of two adjacent pads among the pads  73 B in the Y direction. In addition, at least one of the via holes  83   a  in the inner part  61   aa  is located at the center between the two adjacent ones of the pads  73 A and the two adjacent ones of the pads  73 B in the X direction. In other words, at least one of the via holes  83   a  is located in the center of a region surrounded by the four pads  73 A and  73 B. 
     The via holes  83   a  may include at least one via hole  83   a  located in a different position from the other via holes  83   a . For example, at least one of the via holes  83   a  may be provided in the outer part  61   ab . Furthermore, at least one of the via holes  83   a  may be spaced apart from the center between the two adjacent pads among the pads  73 A in the Y direction. 
     The first wires  83   b  are located on the second conductive layer  19   c  of the FPC  19 . The first wires  83   b  electrically connect the via holes  83   a  and one corresponding pad among the pads  73 . In other words, the first wires  83   b  extend between the pads  73  and the via holes  83   a.    
     The first wires  83   b  electrically connect the via holes  83   a  of the inner part  61   aa  and the pads  73 A, passing a location closer to the pads  73 B than the center between the pads  73 A and the pads  73 B in the X direction. In other words, the first wires  83   b  connected to the pads  73 A extend, crossing the center between the pads  73 A and pads  73 B in the X direction. The first wiring parts  83   b  electrically connecting the via holes  83   a  of the inner part  61   aa  and the pads  73 A are not limited to this example. 
     The second wires  83   c  are provided on the first conductive layer  19   a  of the FPC  19 . The second wires  83   c  extend between the via holes  83   a  and the preamplifiers  81 . Thus, the second wires  83   c  electrically connect the via holes  83   a  and the preamplifiers  81 . Thus, at least one of the pads  73  and the preamplifiers  81  are electrically interconnected via the wires  83  including the via holes  83   a , the first wires  83   b  and the second wires  83   c.    
     The second wires  83   c  electrically connecting the via holes  83   a  of the inner part  61   aa  to the preamplifiers  81  are connected to the via holes  83   a  and extend from the inner part  61   aa  to the outer parts  61   ab . The second wires  83   c  extend in the Y direction in the outer parts  61   ab  and are connected to the preamplifiers  81 . The second wires  83   c  connected to the via holes  83   a  extend in the Y direction substantially in parallel to the outer parts  61   ab . The second wires  83   c  may include a part extending in a direction different from the Y direction in the outer parts  61   ab.    
     The third wires  83   d  are provided on the second conductive layer  19   c  of the FPC  19 . The third wires  83   d  electrically connect the preamplifier  81  and one corresponding pad among the pads  73 . Thus, at least one of the pads  73  and the preamplifiers  81  are electrically interconnected via the wires  83  including the third wires  83   d . At least one of the third wires  83   d  extends in the Y direction substantially in parallel to the outer parts  61   ab.    
     At least two of the pads  55  of the flexure  43  and at least two of the pads  73  of the FPC  19  transmit a differential signal. The via holes  83   a , the first wires  83   b , and the second wires  83   c  are electrically connected to one of the pad pair  73  that transmits a differential signal. The third wires  83   d  are electrically connected to the other of the pad pair  73  that transmits a differential signal. The pads  55  and  73  may transmit an electrical signal different from the differential signal or may include pads  55  and  73  that supply electric power. 
     In the outer parts  61   ab , the second wires  83   c  and the third wires  83   d  at least partially overlap each other in the Z direction. In other words, in the outer parts  61   ab , the second wires  83   c  and the third wires  83   d  cover each other in the Z direction. 
     Two of the pads  73 A are adjacent to each other in the Y direction at a first interval D 1 . Another two of the pads  73 A are adjacent to each other in the Y direction at a second interval D 2 . The second interval D 2  is longer than the first interval D 1 . The pads  73 A are adjacent to each other in the Y direction at the first interval D 1  or the second interval D 2 . Among the pads  73 A, a larger number pads  73 A are spaced at the first interval D 1  than at the second interval D 2 . 
     Two of the pads  73 B are adjacent to each other in the Y direction at a third interval D 3 . Another two of the pads  73 B are adjacent to each other in the Y direction at a fourth interval D 4 . The fourth interval D 4  is longer than the third interval D 3 . The pads  73 B are adjacent to each other in the Y direction at the third interval D 3  or the fourth interval D 4 . Among the pads  73 B, a larger number of pads  73 A are spaced at the third interval D 3  than at the fourth interval D 4 . 
     The length of the first interval D 1  is substantially equal to the length of the third interval D 3 . The length of the second interval D 2  is substantially equal to the length of the fourth interval D 4 . The interval between two adjacent pads  73 A and the interval between two adjacent pads  73 B are not limited to the foregoing example. 
     In the Y direction at least one of the via holes  83   a  is located between the two adjacent pads at the second interval D 2  among the pads  73 A and between the two adjacent pads at the fourth interval D 4  among the pads  73 B. The via holes  83   a  may be spaced apart from the center between the two adjacent pads  73 A and from the center between the two adjacent pads  73 B in the Y direction. 
     As illustrated in  FIG.  5   , the joint  61  of the FPC  19  further includes a first ground plane  91 , a plurality of second ground planes  92 , and a thermal insulation film  93 . The first ground plane  91  is an example of a ground plane. The second ground plane  92  is an example of a conductive layer. The thermal insulation film  93  is an example of a thermal insulation layer. The first ground plane  91  and the second ground planes  92  may be referred to as planes or solid grounds. 
     The first ground plane  91  is provided on the first conductive layer  19   a  of the FPC  19 . The first ground plane  91  is provided on the mount  61   b  of the joint  61 . Hence, the first ground plane  91  is spaced apart from the pads  73  and the joint part  61   a  in the −Y direction. 
     In a Z-directional plan view, the first ground plane  91  is larger in size than the preamplifiers  81 . The first ground plane  91  at least partially overlaps the preamplifiers  81  in the Z direction. In other words, the first ground plane  91  covers the preamplifiers  81  in the Z direction. The preamplifiers  81  may be spaced apart from the first ground plane  91  in a direction along the surface  71 . 
     The second ground planes  92  are provided on the first conductive layer  19   a  of the FPC  19 . The second ground planes  92  are made from metal and have a darker color than the base layer  19   b  and the second insulating layer  19   d . Hence, in the FPC  19 , the area of the second ground planes  92  exhibits a higher absorbance than the rest of the FPC  19 . The FPC  19  may include a part with a higher absorbance than the area of the second ground planes  92 . 
     The second ground planes  92  are provided on the joint part  61   a  of the joint  61 . Hence, the second ground planes  92  are spaced apart from the first ground plane  91  in a direction along the surface  71 . 
     In a Z-direction plan view, the individual second ground planes  92  are larger in size than the individual pads  73 . The second ground planes  92  are spaced apart from at least one of the pads  73  in a direction along the surface  71  and cover at least another one of the pads  73  in the Z direction. One of the second ground planes  92  may cover two or more pads  73  in the Z direction. 
     The second ground planes  92  are electrically connected to the first ground plane  91  via the second wires  83   c , for example. Thus, the first ground plane  91  and the second ground planes  92  are both set at ground potential. The second ground planes  92  may be electrically connected to the first ground plane  91  via conductors different from the second wires  83   c . Furthermore, the second ground planes  92  may be floating so as to be electrically independent from the first ground plane  91 . 
     The joint  61  may include another dark-color layer or layers instead of the second ground planes  92 . For example, the darker-color part of the base layer  19   b  than the rest thereof may be spaced apart from at least one of the pads  73  in a direction along the surface  71  and cover at least another one of the of pads  73  in the Z direction. 
     The thermal insulation film  93  is provided, for example, in-between the first conductive layer  19   a  of the FPC  19  and the first insulating layer or in-between the metal sheet and the first insulating layer. That is, the thermal insulation film  93  is located between the metal sheet with higher thermal conductivity and the first conductive layer  19   a.    
     The thermal insulation film  93  is made from synthetic resin, for example. The thermal insulation film  93  may be made from another material. The thermal insulation film  93  is lower in thermal conductivity than the first conductive layer  19   a  and the second conductive layer  19   c . In addition, the thermal insulation film  93  is equal to or lower in thermal conductivity than the base layer  19   b  and the second insulating layer  19   d.    
     The thermal insulation film  93  is spaced apart from at least one of the pads  73  in a direction along the surface  71  and covers at least another one of the pads  73  in the Z direction. The thermal insulation film  93  may cover two or more pads  73  in the Z direction. 
     At least either the second ground planes  92  or the thermal insulation film  93  is spaced apart, in a direction along the surface  71 , from the pads  73  which are likely to exhibit a temperature rise by fusing of the solder  77 , for example. In addition, at least either the second ground planes  92  or the thermal insulation film  93  covers, in the Z direction, the pads  73  which are unlikely to exhibit a temperature rise by fusing of the solder  77 . Temperature change in the pads  73  due to fusing of the solder  77  can be found through experiment or simulation, for example. 
     An exemplary method for attaching the flexures  43  to the FPC  19  will be described below, however, it is not limited to the one described herein. Other methods may be applied. 
     First, the pads  55  of the flexure  43  or the pads  73  of the FPC  19  are applied with solder paste containing the solder  77 , for example. Then, the joint  61  of the FPC  19  is attached to the actuator block  31  with adhesive and screws, for example. 
     Next, the head suspension assemblies  33  are attached to the arms  32 . As illustrated in  FIG.  3   , the second attachments  52  of the flexures  43  are disposed on the surface  71  of the joint  61 . The pads  55  of the flexures  43  and the pads  73  of the FPC  19  are disposed so as to face each other via the solder paste (solder  77 ). 
     Thereafter, the second attachments  52  of the flexures  43  are pressed against the FPC  19  with a jig J.  FIG.  3    virtually illustrates the jig J by dash-dot-dot lines. The jig J is located between the two adjacent pads spaced at the second interval D 2  among the pads  73 A and located between the two adjacent pads spaced at the fourth interval D 4  among the pads  73 B in the Y direction. The jig J is spaced apart from the pads  55  and  73  in a direction along the surface  71 . 
     The via holes  83   a , which are located between the two adjacent pads spaced at the second interval D 2  among the pads  73 A and between the two adjacent pads spaced at the fourth interval D 4  among the pads  73 B in the Y direction, are covered by the jig J. In the vicinity of the via holes  83   a , the FPC  19  is pressed by the jig J. The jig J may not exert a load on the FPC  19 . 
     Next, the solder paste is fused and the solder  77  mechanically and electrically connects the pads  55  of the flexures  43  and the pads  73  of the FPC  19 . For example, of the second attachments  52 , the parts having the pads  55  mounted thereon are irradiated with a laser beam. By the laser beam, the pads  55  and  73 , the solder paste (solder  77 ), and the vicinity of thereof are heated to fuse the solder paste. The pads  55  and  73 , the solder paste, and the vicinity thereof may be heated with, for example, a pulse heat unit instead of a laser beam. 
     Typically, when heated, moisture between the layers of the FPC  19  expands. In addition, the layers of the FPC  19  mutually differ in thermal expansion coefficient. For this reason and/or another reason, when the temperature of the FPC  19  exceeds a certain value, the layers of the FPC  19  may detach from one another. 
     The larger the number of magnetic disks  12  is, the less the numbers and density of the pads  73  and the wires  83  are and the smaller the solder  77  is. Because of this, in the vicinity of the pads  73  and the via holes  83 , heat concentration and accumulation readily occur. In addition, the structure of the FPC  19  is complex in the vicinity of the via holes  83   a , and the layers are likely to contain moisture in-between them. For this reason, for example, delamination in the FPC  19  is more likely to occur in the vicinity of the pads  73  and the via holes  83   a  than in other locations. 
     In the present embodiment, the via holes  83   a  of the inner part  61   aa  are located far from the pads  73 . In addition, the first wires  83   b  electrically connecting the via holes  83   a  of the inner part  61   aa  and the pads  73  extend long. This can reduce heat transfer from the pads  73  to the via holes  83   a  and reduce the temperature rise in the via holes  83   a  and in the vicinity thereof. Thereby, it is possible to reduce a likelihood of occurrence of the delamination of the FPC  19  in the vicinity of the via holes  83   a.    
     Typically, if the solder paste (the solder  77 ) remains at below a certain temperature, the solder paste is not sufficiently fused. Because of this, the pads  55  and the pads  73  may not be sufficiently connected together with the solder  77 . 
     According to the present embodiment, the first ground plane  91  serves to promote heat dissipation and is spaced apart from the pads  73  in a direction along the surface  71 . This can avoid heat dissipation from the pads  55  and  73  and the solder paste (the solder  77 ). Thereby, the solder  77  is heated at a sufficient temperature and adequately fused to mechanically and electrically connect the pads  55  and the pads  73  properly. 
     In addition, according to the present embodiment, the second ground planes  92  cover, in the Z direction, the pads  73  which is unlikely to exhibit a temperature rise by fusing of the solder  77 . In the FPC  19 , the part having the second ground planes  92  mounted thereon have a darker color and a higher absorbance than the rest. Hence, the pads  55  and  73  covered by the second ground planes  92 , the solder paste (solder  77 ), and the vicinity thereof are then readily heated by means of a laser beam. Thereby, the solder  77  is heated at a sufficient temperature and adequately fused to mechanically and electrically connect the pads  55  and the pads  73  properly. 
     In addition, according to the present embodiment, the thermal insulation film  93  covers, in the Z direction, the pads  73  which is unlikely to exhibit a temperature rise by fusing of the solder  77 . This can avoid heat dissipation from the pads  55  and  73  and the solder paste (the solder  77 ) to the metal sheet of the FPC  19 , for example. Thereby, the solder  77  is heated at a sufficient temperature and adequately fused to mechanically and electrically connect the pads  55  and the pads  73  properly. 
     In addition, according to the present embodiment, the second ground planes  92  and the thermal insulation film  93  are spaced apart, in a direction along the surface  71 , from the pads  73  which is likely to rise in temperature by fusing of the solder  77 . This can reduce the temperature rise in the pads  73  and reduce a likelihood of occurrence of the delamination of the FPC  19  in the vicinity of the pads  73 . 
     By the method as above, the flexures  43  are attached to the FPC  19 . The flexures  43  may be individually or collectively subjected to the foregoing procedures. 
     According to the HDD  1  of the first embodiment described above, the FPC  19  includes the surface  71 , the pads  73  mounted on the surface  71  and connected to the pads  55  by means of the solder  77 , and the first ground plane  91  spaced apart from the pads  73  in a direction along the surface  71 . The first ground plane  91  is made from metal and has a high thermal conductivity. Hence, typically, the vicinity of the first ground plane  91  is readily coolable. According to the present embodiment, the first ground plane  91  is spaced apart from the pads  73 , so that the solder  77  readily rises in temperature to the fusing point at the time of connecting the pads  73  to the pads  55  by means of the solder  77 . Thus, according to the HDD  1  of the present embodiment, the FPC  19  is readily adjustable in temperature at the time of connecting the pads  55  and  73 . This can avoid degradation of the quality of the FPC  19 , such as a loose connection between the pads  55  and  73  due to insufficient fusing of the solder  77 . In addition, the first ground plane  91  can be reduced in size, enabling cost reduction of the HDD  1 . 
     The FPC  19  includes the joint part  61   a  on which the pads  73  are mounted, and the mount  61   b  on which the preamplifiers  81  are mounted. The first ground plane  91  is placed on the mount  61   b  with spacing from the joint part  61   a  in a direction along the surface  71 . That is, the first ground plane  91  is further away from the pads  73 , enabling the solder  77  to rise in temperature to the fusing point at the time of connecting the pads  73  to the pads  55  by means of the solder  77 . Thus, according to the HDD  1  of the present embodiment, the FPC  19  is readily adjustable in temperature at the time of connecting the pads  55  and  73 . This can avoid degradation of the quality of the FPC  19 , such as a loose connection between the pads  55  and  73  due to insufficient fusing of the solder  77 . 
     The pads  73  include the pads  73 A arranged at intervals in the Y direction along the surface  71 . The FPC  19  includes the via holes  83   a  and the first wires  83   b  which electrically connect the via holes  83   a  and one of the pads  73 A. The via holes  83   a  are located in the middle of two adjacent pads among the pads  73 A in the Y direction. In other words, in the Y direction the distances between the via holes  83   a  and the two pads  73 A closest to the via holes  83   a  are substantially the same distance. That is, the via holes  83   a  are disposed farthest from the two adjacent pads  73 A in the Y direction. Typically, at the temperature above a certain value in the vicinity of the via holes  83   a , delamination may occur in the FPC  19 . According to the present embodiment, the via holes  83   a  are disposed far from the pads  73 A, so that it is possible to decrease a temperature rise in the via holes  83   a  at the time of connecting the pads  73  to the pads  55  by means of the solder  77 . Thus, according to the HDD  1  of the present embodiment, the FPC  19  is readily adjustable in temperature at the time of connecting the pads  55  and  73 . This can avoid degradation of the quality of the FPC  19 , such as the delamination of the FPC  19  due to the temperature rise in the vicinity of the via holes  83   a.    
     The pads  73  include the pads  73 B arranged at intervals in the Y direction with spacing from the pads  73 A in the X direction intersecting the Y direction and along the surface  71 . The via holes  83   a  are located in the middle of two adjacent pads among the pads  73 A in the Y direction, in the middle of two adjacent pads among the pads  73 B in the Y direction, and between the two adjacent pads  73 A and the two adjacent pads  73 B in the X direction. That is, the via holes  83   a  are located farthest from the two adjacent pads  73 A and the two adjacent pads  73 B in-between them in the Y direction. In addition, the via holes  83   a  are disposed farthest from the pads  73 A and the pads  73 B in-between them in the X direction. Owing to the far location of the via holes  83   a  from the pads  73 A and the pads  73 B, a temperature rise in the via holes  83   a  can be lowered at the time of connecting the pads  73  to the pads  55  by means of the solder  77 . Thus, according to the HDD  1  of the present embodiment, the FPC  19  is readily adjustable in temperature at the time of connecting the pads  55  and  73 . This can avoid degradation of the quality of the FPC  19 , such as the delamination of the FPC  19  due to a temperature rise in the vicinity of the via holes  83   a.    
     The first wires  83   b  electrically connect the via holes  83   a  and one of the pads  73 A through the location closer to the pads  73 B than the center between the pads  73 A and the pads  73 B in the X direction. This allows the first wires  83   b  to extend long, reducing the thermal conductivity between the pads  73 A and the via holes  83   a  and hence reducing a temperature rise in the via holes  83   a  at the time of connecting the pads  73  to the pads  55  by means of the solder  77 . Thus, according to the HDD  1  of the present embodiment, the FPC  19  is readily adjustable in temperature at the time of connecting the pads  55  and  73 . This can avoid degradation of the quality of the FPC  19 , such as the delamination of the FPC  19  due to the temperature rise in the vicinity of the via holes  83   a.    
     The FPC  19  includes the inner part  61   aa , the outer parts  61   ab , and the second wires  83   c . The inner part  61   aa  is located between the pads  73 A and the pads  73 B in the X direction and provided with the via holes  83   a . The outer parts  61   ab  are spaced further from the inner part  61   aa  than the pads  73 A in the X direction. The second wires  83   c  are electrically connected to the via holes  83   a , extend in the Y direction in the outer parts  61   ab , and electrically connect the preamplifiers  81  and the via holes  83   a . That is, the via holes  83   a  are disposed in a concentrated manner in the inner part  61   aa , and the second wires  83   c  extend in the Y direction in a concentrated manner in the outer parts  61   ab . The wiring design of the FPC  19  can thus be simplified. 
     Among the pads  73 A, two pads are adjacent to each other at the first interval D 1 , and another two pads are adjacent to each other at the second interval D 2  longer than the first interval D 1 . Among the pads  73 B, two pads are adjacent to each other at the third interval D 3 , and another two pads are adjacent to each other at the fourth interval D 4  longer than the third interval D 3 . This arrangement allows the jig J for pressing the flexures  43  against the FPC  19  to be disposed in the region between the two adjacent pads  73 A at the second interval D 2  and in the region between the two adjacent pads  73 B at the fourth interval D 4 . In the Y direction the via holes  83   a  are located between the two adjacent pads  73 A at the second interval D 2  and between the two adjacent pads  73 B at the fourth interval D 4 . This arrangement allows the jig J to be able to press the FPC  19  in the vicinity of the via holes  83   a , leading to preventing the delamination of the FPC  19  in the vicinity of the via holes  83   a.    
     The pads  55  and  73  are configured to transmit a differential signal. This eliminates the necessity to place the first ground plane  91  on the wires  83  electrically connected to the pads  73 , and allow the first ground plane  91  to be separated from the pads  73 . Thereby, the solder  77  can readily rise in temperature to the fusing point at the time of connecting the pads  73  to the pads  55  by means of the solder  77 . This can avoid degradation of the quality of the FPC  19 , such as a loose connection between the pads  55  and  73  due to insufficient fusing of the solder  77 . In addition, in the circuitry that transmits a differential signal, typically, the substrate may be provided with the via holes  83   a  in order to overlay two wires along the thickness of the substrate. In the present embodiment, the via holes  83   a  are disposed farthest from the two pads  73 A in-between them in the Y direction. Thereby, the temperature rise in the via holes  83   a  is reduced at the time of connecting the pads  73  to the pads  55  by means of the solder  77 . This can avoid degradation of the quality of the FPC  19 , such as the delamination of the FPC  19  due to the temperature rise in the vicinity of the via holes  83   a.    
     The FPC  19  includes the second ground planes  92 . The second ground planes  92  are spaced apart from one of the pads  73  in a direction along the surface  71  and cover another one of the pads  73  in a direction orthogonal to the surface  71 . In the FPC  19 , typically, the part having the first ground plane  91  mounted thereon has a dark color. The dark-colored parts are readily heated by means of a laser beam, for example, due to a high absorbance. By placing the second ground planes  92  away from the not-readily coolable pads  73  to cover the readily coolable pads  73 , for example, the temperature of the solder  77  on the pads  73  can be adjusted at the time of connecting the pads  73  to the pads  55  by means of the solder  77  fused by a laser beam. Thus, according to the HDD  1  of the present embodiment, the FPC  19  is readily adjustable in temperature at the time of connecting the pads  55  and  73 . This can avoid degradation of the quality of the FPC  19 , such as a loose connection or the delamination. 
     The second ground planes  92  are electrically connected to the first ground plane  91 . This can prevent the second ground planes  92  from undesirably functioning as antennas. 
     The FPC  19  includes the thermal insulation film  93 . The thermal insulation film  93  is spaced apart from one of the pads  73  in a direction along the surface  71  and covers another one of the pads  73  in a direction orthogonal to the surface  71 . For example, by placing the thermal insulation film  93  apart from the not-readily coolable pads  73  to cover the readily coolable pads  73  at the time of connecting the pads  73  to the pads  55  by means of the solder  77 , the temperature of the solder  77  on the pads  73  can be adjusted. Thus, according to the HDD  1  of the present embodiment, the FPC  19  is readily adjustable in temperature at the time of connecting the pads  55  and  73 . This can avoid degradation of the quality of the FPC  19 , such as a loose connection or delamination. 
     Second Embodiment 
     A second embodiment will be described below with reference to  FIG.  6   . In the following embodiment, constituent elements having the same functions as the constituent elements already described are denoted by the same reference numbers and descriptions thereof may be omitted. The constituent elements denoted by the same reference signs may not have all functions and properties in common and may have dissimilar functions and properties according to each of the embodiments. 
       FIG.  6    is an exemplary plan view schematically illustrating part of the FPC  19  according to the second embodiment.  FIG.  6    omits depicting the second insulating layer  19   d . As illustrated in  FIG.  6   , the pads  73  include a plurality of inner pads  73   i  and a plurality of outer pads  73   o . The inner pad  73   i  is an example of an inner terminal. The outer pad  73   o  is an example of an outer terminal. 
     The inner pads  73   i  among the pads  73  are located in the vicinity of the central part of the joint  61 . The outer pads  73   o  among the pads  73  are located in the outer periphery of the joint  61 . That is, the outer pads  73   o  are closer to the edge  72  of the joint  61  than the inner pads  73   i.    
     For example, the pads  73 A and  73 F are the outer pads  73   o . The pads  73 B,  73 C,  73 D, and  73 E include the inner pads  73   i  and the outer pads  73   o.    
     The second ground planes  92  and the thermal insulation film  93  are spaced apart from at least one of the inner pads  73   i  in a direction along the surface  71  and cover at least one of the outer pads  73   o  in a direction orthogonal to the surface  71 . Depending on a temperature change in the pads  73  at the time of fusing the solder  77 , at least either of the second ground planes  92  and the thermal insulation film  93  may be spaced apart from at least one of the outer pads  73   o  in a direction along the surface  71  and may cover at least one of the inner pads  73   i  in a direction orthogonal to the surface  71 . 
     According to the HDD  1  of the second embodiment, the pads  73  include the inner pads  73   i  and the outer pads  73   o  closer to the edge  72  of the FPC  19  than the inner pads  73   i . The second ground planes  92  are spaced apart from the inner pads  73   i  in a direction along the surface  71  and cover the outer pads  73   o  in a direction orthogonal to the surface  71 . Typically, the outer pads  73   o  can dissipate heat from the edge  72  of the FPC  19  and are thus readily coolable. The inner pads  73   i  are far from the edge  72  of the FPC  19  and are thus not readily coolable. According to the present embodiment, by placing the second ground planes  92  apart from the inner pads  73   i  to cover the outer pads  73   o , the solder  77  on the outer pads  73   o  can readily rise in temperature to the fusing point at the time of connecting the pads  73  to the pads  55  by means of the solder  77 . In addition, the temperature rise in the solder  77  on the inner pads  73   i  is reduced. Thus, according to the HDD  1  of the present embodiment, the FPC  19  is readily adjustable in temperature at the time of connecting the pads  55  and  73 . This can avoid degradation of the quality of the FPC  19 , such as a loose connection or delamination. 
     The thermal insulation film  93  is spaced apart from the inner pads  73   i  in a direction along the surface  71  and covers the outer pads  73   o  in a direction orthogonal to the surface  71 . Hence, at the time of connecting the pads  73  to the pads  55  by means of the solder  77 , the temperature of the solder  77  on the outer pads  73   o  readily rises to the fusing point. In addition, the rise in temperature of the solder  77  on the inner pads  73   i  is reduced. Thus, according to the HDD  1  of the present embodiment, the FPC  19  is readily adjustable in temperature at the time of connecting the pads  55  and  73 . This can avoid degradation of the quality of the FPC  19 , such as a loose connection or delamination. 
     In the HDD  1 , the via holes  83   a  and the first ground plane  91  may be disposed in a different manner from at least one of the first and second embodiments. Furthermore, the HDD  1  may exclude at least either of the second ground planes  92  and the thermal insulation film  93 . By such modification, the FPC  19  is readily adjustable in temperature at the time of connecting the pads  55  and  73 . 
     According to at least one of the first and second embodiments, the flexible printed circuit board includes a surface; a plurality of second terminals located on the surface to be connected to a plurality of first terminals by means of a conductive adhesive; and a ground plane spaced apart from the second terminals in a direction along the surface. The ground plane is made from metal and has a higher thermal conductivity. Hence, typically, the vicinity of the ground plane is readily coolable. According to the present embodiment, due to the location of the ground plane apart from the second terminals, the temperature of the solder readily rises to the fusing point at the time of connecting the second terminals to the first terminals by means of a conductive adhesive such as solder. That is, according to the disk device of the present embodiment, the temperature of the flexible printed circuit board is readily adjustable in connecting the first terminals to the second terminals. This makes it possible to avoid degradation of the quality of the flexible printed circuit board, such as a loose connection between the first terminals and the second terminals due to insufficient fusing of the solder. In addition, the ground plane can be reduced in size, enabling cost reduction of the disk device. 
     At least one of the above embodiments includes at least the following features. 
     (1) A disk device includes a recording medium of a disk form including a recording layer; a magnetic head configured to read and write information from and to the recording medium; a wiring member including a plurality of first terminals, and a plurality of first wires that electrically connect the magnetic head to the plurality of first terminals; and a flexible printed circuit board including a surface, a plurality of second terminals located on the surface to be connected to the plurality of first terminals by means of a conductive adhesive, and a ground plane spaced apart from the plurality of second terminals in a direction along the surface. 
     (2) A disk device includes a recording medium of a disk form including a recording layer; a magnetic head configured to read and write information from and to the recording medium; a wiring member including a plurality of first terminals, and a plurality of first wires that electrically connect the magnetic head and the plurality of first terminals; and a flexible printed circuit board including a surface, and a plurality of second terminals located on the surface to be connected to the plurality of first terminals by means of a conductive adhesive, wherein the plurality of second terminals include a plurality of first electrodes arranged at intervals in a first direction along the surface, the flexible printed circuit board is provided with a via hole and a second wire that electrically connects the via hole and one of the plurality of first electrodes, and the via hole is located in the middle of two adjacent first electrodes among the plurality of first electrodes in the first direction. 
     (3) A disk device includes a recording medium of a disk form including a recording layer; a magnetic head configured to read and write information from and to the recording medium; a wiring member including a plurality of first terminals, and a plurality of first wires that electrically connect the magnetic head and the plurality of first terminals; and a flexible printed circuit board including a surface, a plurality of second terminals located on the surface to be connected to the plurality of first terminals by means of a conductive adhesive, and a conductive layer spaced apart from one of the plurality of second terminals in a direction along the surface and covering another one of the plurality of second terminals in a direction orthogonal to the surface. 
     (4) A disk device includes a recording medium of a disk form including a recording layer; a magnetic head configured to read and write information from and to the recording medium; a wiring member including a plurality of first terminals, and a plurality of first wires that electrically connect the magnetic head and the plurality of first terminals; and a flexible printed circuit board including a surface, a plurality of second terminals located on the surface to be connected to the plurality of first terminals by means of a conductive adhesive, and a thermal insulation layer spaced apart from one of the plurality of second terminals in a direction along the surface and covering another one of the plurality of second terminals in a direction orthogonal to the surface. 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.