Suspension Assembly and Disk Device

Abstract

To provide a suspension assembly which can improve narrow pitching of wiring and bondability of a connection terminal while strength of the connection terminal is maintained, and to provide a disk device including the suspension assembly.SOLUTION: A suspension assembly includes: a support plate; a head supported by the support plate; and a wiring member installed in the support plate. The wiring member includes: a tip part which is electrically connected to the head; a connection end part extended to an outer side of the support plate; and a plurality of wirings extending between the tip part and the connection end part. The connection tip part includes: a cover layer with an opening; 13 or more connection terminals which face the opening, are arranged in a row in a length direction of the opening by leaving intervals and are connected to the wirings; and a base layer which is provided by being overlapped on the cover layer and the connection terminals and includes a plurality of first openings facing a part of the connection terminals and a plurality of second openings facing a space part between the adjacent connection terminals.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] Embodiments of the present invention relate to a suspension assembly used in a disk device and a disk device including the same.

Background Art

[0002] As a disk device, for example, a magnetic disk device generally includes a magnetic disk disposed in a base, a spindle motor that supports and rotationally drives the magnetic disk, and a head actuator. The head actuator has a plurality of suspension assemblies each supporting a magnetic head. Each suspension assembly includes a suspension attached to the tip of the arm of the head actuator and a wiring member (flexure, wiring trace) installed on the suspension. A magnetic head is supported by the gimbal portion of the wiring member, and a head suspension assembly is configured. A plurality of connection terminals are provided at the connection end of the wiring member. These connection terminals are electrically connected to the magnetic head via the wiring of the wiring member. Then, the connection terminals at the connection end are soldered to the connection pads of a flexible printed wiring board (FPC) provided on the actuator block.

[0003] In recent magnetic disk devices, in order to achieve further high density and improved reliability, consideration is being given to adding functions such as an HDI (head-disk interface) sensor, a multi-stage actuator, a DFH (dynamic fly height) control function, high-frequency assist recording, or thermal assist recording to the head or the suspension assembly. Along with this, it is necessary to further increase the number of wirings of the wiring member and the number of connection terminals provided at the connection end.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] In order to secure an area for arranging a large number of wirings, it is necessary to reduce the wiring width and route the wirings in a narrow pitch. Further, in order to reduce the pitch, it is necessary to reduce the thickness of the wiring. However, when the wiring is made thinner, the connection terminals (flying leads) formed on the same layer as the wiring also become thinner, resulting in a problem of reduced strength. Therefore, an object of an embodiment of the present invention is to provide a suspension assembly and a disk device including the same that can achieve narrow pitch of wirings and improvement in joinability of connection terminals while maintaining the strength of the connection terminals.

Means for Solving the Problems

[0006] According to an embodiment, a suspension assembly includes a support plate, a head supported by the support plate, and a wiring member installed on the support plate. The wiring member has a tip portion electrically connected to the head, a connection end portion extending outside the support plate, and a plurality of wirings extending between the tip portion and the connection end portion. The connection end portion includes a cover layer provided with an opening having a predetermined length, 13 or more connection terminals arranged side by side at intervals in the length direction facing the opening and each connected to the wiring, and a base layer provided so as to overlap the cover layer and the connection terminals and having a plurality of first openings facing a part of each connection terminal and a plurality of second openings facing a space portion between the adjacent connection terminals.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Embodiments for Carrying Out the Invention

[0008] The disk device according to the embodiment will be described with reference to the following drawings. Note that the disclosure is merely an example, and for those skilled in the art, appropriate modifications that maintain the gist of the invention and can be easily conceived are naturally included in the scope of the present invention. Also, for the purpose of making the description clearer, the drawings may schematically represent the width, thickness, shape, etc. of each part compared to the actual aspect, but this is merely an example and does not limit the interpretation of the present invention. Further, in this specification and each drawing, the same reference numerals may be assigned to the same elements as those described above with respect to the previously presented drawings, and detailed descriptions may be appropriately omitted.

[0009] (First Embodiment) As a disk device, the hard disk drive (HDD) according to the first embodiment will be described in detail. FIG. 1 is an exploded perspective view of the HDD according to the first embodiment shown with the top cover removed. The HDD includes a flat, substantially rectangular housing 10. The housing 10 has a rectangular box-shaped base 12 with an open top surface and a top cover 14. The base 12 has a rectangular bottom wall 12a facing the top cover 14 with a gap therebetween, and a plurality of side walls 12b erected along the periphery of the bottom wall 12a, and is integrally formed of, for example, aluminum. The top cover 14 is formed in a rectangular plate shape of, for example, stainless steel. The top cover 14 is screwed onto the side walls 12b of the base 12 by a plurality of screws 13 to close the upper opening of the base 12.

[0010] Inside the housing 10, a plurality of magnetic disks 18 as recording media and a spindle motor 19 as a driving unit for supporting and rotating the magnetic disks 18 are provided. The spindle motor 19 is disposed on the bottom wall 12a. Each magnetic disk 18 is formed, for example, in a disk shape with a diameter of 96 mm (3.5 inches), and has a substrate made of a non-magnetic material such as glass or aluminum, and a magnetic recording layer formed on the upper surface and / or lower surface of the substrate. The magnetic disks 18 are coaxially fitted to a hub (not shown) of the spindle motor 19 and clamped by a clamp spring 20, and are fixed to the hub. The magnetic disks 18 are supported in a state parallel to the bottom wall 12a of the base 12. The plurality of magnetic disks 18 are rotated at a predetermined rotational speed by the spindle motor 19. In this embodiment, for example, five magnetic disks 18 are accommodated in the housing 10, but the number of magnetic disks 18 is not limited to this.

[0011] Inside the housing 10, a plurality of magnetic heads 17 for recording and reproducing information with respect to the magnetic disks 18, and an actuator assembly (carriage assembly) 22 that movably supports these magnetic heads 17 with respect to the magnetic disks 18 are provided. Also, inside the housing 10, a voice coil motor (hereinafter referred to as VCM) 24 for rotating and positioning the actuator assembly 22, a ramp load mechanism 25 for holding the magnetic heads 17 at an unload position separated from the magnetic disks 18 when the magnetic heads 17 move to the outermost periphery of the magnetic disks 18, and a substrate unit (FPC unit) 21 on which electronic components such as a conversion connector are mounted are provided. The actuator assembly 22 and the VCM 24 constitute a head actuator. The actuator assembly 22 has an actuator block 29 rotatably supported around a support shaft 26 via a bearing unit 28, a plurality of arms 32 extending from the actuator block 29, and a suspension assembly 30 extending from each arm 32. A magnetic head 17 is supported at the tip of each suspension assembly 30. The support shaft 26 is erected on the bottom wall 12a. The magnetic head 17 includes a read head, a write head, an assist element, a heater, etc.

[0012] A printed circuit board (not shown) is screwed to the outer surface of the bottom wall 12a of the base 12. The printed circuit board constitutes a control unit, which controls the operation of the spindle motor 19 and also controls the operations of the VCM 24 and the magnetic head 17 via the substrate unit 21.

[0013] FIG. 2 is a perspective view showing the actuator assembly and the FPC unit, and FIG. 3 is a perspective view showing the suspension assembly. As shown in FIG. 2, the actuator assembly 22 includes an actuator block 29 having a through hole 31, a bearing unit (unit bearing) 28 provided in the through hole 31, a plurality of, for example, six arms 32 extending from the actuator block 29, a suspension assembly 30 attached to each arm 32, and a magnetic head 17 supported by the suspension assembly 30. The actuator block 29 is rotatably supported by a bearing unit 28 around a support shaft (pivot) 26 erected on the bottom wall 12a.

[0014] In this embodiment, the actuator block 29 and the six arms 32 are integrally formed of aluminum or the like, constituting a so-called E-block. The arms 32 are formed, for example, in an elongated flat plate shape and extend from the actuator block 29 in a direction perpendicular to the support shaft 26. The six arms 32 are provided in parallel with gaps between them. The actuator assembly 22 has a support frame 36 that extends from the actuator block 29 in a direction opposite to the arm 32, and the voice coil 34 is supported by this support frame 36. As shown in FIG. 1, the voice coil 34 is located between a pair of yokes 38, one of which is fixed on the base 12, and together with these yokes 38 and the magnets fixed to any of the yokes, it constitutes the VCM 24.

[0015] The actuator assembly 22 includes ten suspension assemblies 30 that respectively support the magnetic heads 17, and these suspension assemblies 30 are respectively attached to the tip portions 32a of the respective arms 32. The plurality of suspension assemblies 30 include an up-head suspension assembly that supports the magnetic head 17 upward and a down-head suspension assembly that supports the magnetic head 17 downward. These up-head suspension assemblies and down-head suspension assemblies are configured by arranging the suspension assemblies 30 having the same structure with their up-and-down directions reversed. In the present embodiment, as shown in FIG. 2, a down-head suspension assembly 30 is attached to the uppermost arm 32, and an up-head suspension assembly 30 is attached to the lowermost arm 32. An up-head suspension assembly 30 and a down-head suspension assembly 30 are attached to each of the four intermediate arms 32.

[0016] As shown in FIG. 3, the suspension assembly 30 has a substantially rectangular base plate 44, an elongated plate spring-like load beam 46, and an elongated strip-shaped flexure (wiring member) 48. The base end portion of the load beam 46 is fixed by overlapping it with the end portion of the base plate 44. The load beam 46 extends from the base plate 44 and is formed to taper toward the extending end. The base plate 44 and the load beam 46 are formed of, for example, stainless steel and constitute a support plate (suspension).

[0017] The base plate 44 has a circular opening at its base end and an annular protrusion 51 positioned around this opening. The protrusion 51 of the base plate 44 is fitted into the caulking hole 40 formed at the tip 32a of the arm 32, and by caulking this protrusion 51, the base plate 44 is fastened to the tip 32a of the arm 32 (see Fig. 2). The base end of the load beam 46 is arranged overlapping the tip of the base plate 44 and is fixed to the base plate 44 by welding at a plurality of locations.

[0018] The flexure 48 of the suspension assembly 30 has a metal plate (lining layer) such as stainless steel serving as a base, and a flexible printed circuit board (FPC) installed on this metal plate, forming an elongated strip-shaped laminate. The flexure 48 has a tip-side portion 48a and a base-side portion 48b. The tip-side portion 48a is attached to the load beam 46 and the base plate 44. The base-side portion 48b extends outward from the side edge of the base plate 44 and further extends along the arm 32 to the base end of the arm 32 (actuator block 29). The flexure 48 has a tip portion positioned on the load beam 46 and a displaceable gimbal portion (elastic support portion) 52 formed at this tip portion. The magnetic head 17 is mounted on the gimbal portion 52. Also, a pair of piezoelectric elements 53 constituting the micro actuator are mounted on the gimbal portion 52 and are arranged on both sides of the magnetic head 17. The tip portion of the flexure 48 is electrically connected to the lead head element, light head element, heater, assist element, HDI sensor, other members, and the piezoelectric element 53 of the magnetic head 17 via wiring and connection pads (not shown).

[0019] The flexure 48 has a connection end portion (tail connection end portion) 48c provided at one end of the proximal end side portion 48b. The connection end portion 48c is formed in an elongated rectangular shape. The connection end portion 48c is bent at a substantially right angle with respect to the proximal end side portion 48b and is positioned substantially perpendicular to the arm 32. A plurality of, for example, 13 connection terminals (connection pads) 50 are provided on the connection end portion 48c. These connection terminals 50 are respectively connected to the wirings of the flexure 48. That is, the plurality of wirings of the flexure 48 extend over substantially the entire length of the flexure 48, one end is electrically connected to the magnetic head 17, and the other end is connected to the connection terminals (connection pads) 50 of the connection end portion 48c.

[0020] As shown in FIG. 2, ten suspension assemblies 30 extend from six arms 32, face each other substantially in parallel, and are arranged side by side with a predetermined interval therebetween. These suspension assemblies 30 constitute five down-head suspension assemblies and five up-head suspension assemblies. Each set of the down-head suspension assembly 30 and the up-head suspension assembly 30 are positioned parallel to each other with a predetermined interval therebetween, and the magnetic heads 17 are positioned facing each other. These magnetic heads 17 are positioned to face both surfaces of the corresponding magnetic disk 18.

[0021] As shown in FIG. 2, the FPC unit 21 integrally has a substantially rectangular base portion 60, an elongated strip-shaped relay portion 62 extending from one side edge of the base portion 60, and a substantially rectangular joint portion (FPC joint portion) 64 continuously provided at the tip of the relay portion 62. These base portion 60, relay portion 62, and joint portion 64 are formed by a flexible printed wiring board (FPC). On one surface (outer surface) of the base portion 60, electronic components such as a conversion connector (not shown) and a plurality of capacitors 63 are mounted and electrically connected to wiring (not shown). On the other surface (inner surface) of the base portion 60, two metal plates 70 and 71 that function as reinforcing plates are respectively attached. The base portion 60 is disposed on the bottom wall 12a of the housing 10 and is screwed to the bottom wall 12a by two screws. The conversion connector on the base portion 60 is connected to a control circuit board provided on the bottom surface side of the housing 10.

[0022] The relay portion 62 extends from the base portion 60 toward the actuator assembly 22. The joint portion 64 provided at the extending end of the relay portion 62 is formed in a rectangular shape having substantially the same height and width as the side surface (installation surface) of the actuator block 29. The joint portion 64 is attached to the installation surface of the actuator block 29 via a backing plate formed of aluminum or the like, and is further fixed to the installation surface by fixing screws.

[0023] The connection end portions 48c of the ten flexies 48 are joined to a plurality of connection portions of the joint portion 64 and are electrically connected to the wiring of the joint portion 64. The plurality of connection end portions 48c are arranged side by side in a direction parallel to the support shaft 26. A head IC (head amplifier) 54 is mounted on the joint portion 64, and this head IC 54 is connected to the connection end portions 48c and the base portion 60 via the wiring of the FPC. Further, the joint portion 64 has a pair of connection pads 55, and the voice coil 34 is connected to these connection pads 55. The ten magnetic heads 17 of the actuator assembly 22 are each electrically connected to the base portion 60 through the wiring of the flexy 48, the connection end portion 48c, the joint portion 64 of the FPC unit 21, and the relay portion 62. Further, the base portion 60 is electrically connected to the printed circuit board on the bottom surface side of the housing 10 via a conversion connector.

[0024] The wiring structure of the joint portion 64 will be described in detail. FIG. 4 is a side view showing the joint portion 64 attached to the actuator block and a plurality of connection end portions, and FIG. 5 is a side view showing the joint portion 64 before joining the connection end portions. As shown in FIG. 5, the joint portion 64 has ten connection pad groups 72 corresponding to the connection end portion 48c of the suspension assembly 30. Each connection pad group 72 has a plurality of, for example, thirteen connection pads 73 arranged in a row. Each connection pad 73 is electrically connected to the head IC 54 or the base portion 60 via wiring. The thirteen connection pads 73 of each connection pad group 72 are arranged in a row at a predetermined interval from each other in a direction substantially parallel to the arm 32. Also, the ten connection pad groups 72 are arranged at a predetermined interval from each other and substantially parallel to each other in a direction parallel to the support shaft 26, that is, in the height direction of the actuator block 29. These connection pads 73 are located within a strip-shaped opening 76 formed in the cover insulating layer of the FPC described later and are exposed to the outside through this opening. Also, in a state before joining the connection end portion 48c, a solder layer 78 is formed on each connection pad 73.

[0025] As shown in FIGS. 4 and 5, the joint portion 64 of the FPC is fixed to the installation surface of the actuator block 29 via a backing plate. The connection end portion 48c of the flexure 48 is disposed overlapping each connection pad group 72 of the joint portion 64. The connection terminals 50 of the connection end portion 48c are each in contact with the corresponding connection pad 73 via the solder layer 78. As described later, by laser irradiation, the solder layer 78 is melted, and each connection terminal 50 is soldered mechanically and electrically to the corresponding connection pad 73.

[0026] Next, the configuration of the flexure 48 and the detailed configuration of the connection end portion 48c will be described. FIG. 6 is a cross-sectional view showing the laminated structure of the flexure 48, and FIG. 7 is a plan view showing an enlarged connection end portion of the flexure. As shown in FIG. 6, the flexure 48 has a metal plate (lining layer) 80 such as stainless steel serving as a base layer and a flexible printed circuit board (FPC) 82 formed on this metal plate. In the present embodiment, an adhesive layer (heat insulating layer) 84 is provided between the metal plate 80 and the FPC 82. Further, the FPC 82 is composed of a laminate having a base insulating layer 86a, a conductive layer 86b laminated on the base insulating layer 86a, and a cover insulating layer (protective layer) 86c laminated so as to overlap the base insulating layer 86a and the conductive layer 86b. The base insulating layer 86a and the cover insulating layer 86c are formed of, for example, polyimide. The conductive layer 86b is formed of, for example, copper foil, and by patterning this copper foil, a plurality of wirings, connection terminals, and connection pads are formed. The film thickness of the conductive layer (copper foil) 86b is formed to be, for example, 9 μm or less. Note that the FPC 82 is not limited to a single-layer structure, and an FPC having a multilayer structure with a plurality of conductive layers and a plurality of cover insulating layers can also be used. Further, the adhesive layer (heat insulating layer) 84 can be omitted.

[0027] As shown in FIG. 7, the connection end portion 48c of the flexure 48 is formed in a substantially elongated rectangular shape having a length L1 and a width W1. The connection end portion 48c has a metal plate 80, a base insulating layer 86a provided on the metal plate 80, a conductive layer 86b provided on the base insulating layer 86a and forming wirings and connection terminals, and a cover insulating layer 86c formed so as to overlap the conductive layer 86b and the base insulating layer 86a. In FIG. 7, the lowermost layer is the cover insulating layer 86c and the uppermost layer is the metal plate 80. It is assumed that the side of the cover insulating layer 86c abuts on the joint portion 64 of the FPC unit. The cover insulating layer 86c has a rectangular opening 90 formed in its central portion. The opening 90 is formed, for example, with a length L2 in the longitudinal direction of 6 mm or less and a width W2 of 0.5 mm. The 13 connection terminals 50 described above are respectively arranged facing the opening 90 and are arranged at intervals in the longitudinal direction of the opening 90. Each connection terminal 50 has, for example, a rectangular shape and extends from one end to the other end in the width direction of the cover insulating layer 86c. The central portion (flying lead) in the longitudinal direction of the connection terminal 50 faces the opening 90, and both end portions in the longitudinal direction of the connection terminal 50 are located overlapping the cover insulating layer 86c. In the cover insulating layer 86c, a plurality of wirings S are respectively allocated and provided in regions on both sides in the width direction of the opening 90. Each connection terminal 50 is connected to the wiring S. Thereby, the 13 connection terminals 50 are electrically connected to the connection pads at the tip of the flexible substrate 48 via the wiring S. The base insulating layer 86a is provided so as to overlap the entire surface of the cover insulating layer 68c, the 13 connection terminals 50, and the wiring S. The metal plate 80 has a substantially rectangular opening 91 formed in its central portion. The opening 91 is formed with a length and width that are sufficiently larger than the opening 90 of the cover insulating layer 68c. Thereby, the metal plate 80 covers the outer peripheral edge portion and the base end portion of the connection end portion 48c.

[0028] FIG. 8 is a plan view showing a partially enlarged connection end portion 48c. As shown in FIGS. 7 and 8, the width (interval between a pair of side edges) WT of the central portion of each connection terminal 50 facing the opening 90 of the cover insulating layer 68c is formed, for example, to be 0.2 mm. The interval WS between the connection terminals 50 is set to be 0.15 mm or more. An interval WS or a gap is provided between one end in the longitudinal direction of the opening 90 and the connection terminal 50, and between the other end in the longitudinal direction of the opening 90 and the connection terminal 50, respectively. The interval between the connection terminals 50 may be set evenly, but in this embodiment, a wide interval (for example, 0.3 mm) is set every three connection terminals 50 from the extending end side of the connection end portion 48c. These wide interval portions are provided for installing a jig when soldering the connection terminals 50.

[0029] A through-hole 50a is provided at the center of each connection terminal 50. In one example, the through-hole 50a has a substantially rectangular shape. The width W3 of the through-hole 50a is smaller than the width WT of the connection terminal 50, and the length is smaller than the width W2 of the opening 90. The through-hole 50a communicates with the opening 90. The ratio of the area of all the connection terminals 50 (including the through-hole portion) to the area of the opening 90 is 40% or more, for example, 43%.

[0030] In the present embodiment, the 13 connection terminals 50 are arranged in the following order in consideration of the influence of crosstalk. As shown in FIG. 7, in one example, from the extending end side of the connection end portion 48c, four connection terminals 50 (R) for the lead head, two connection terminals 50 (S) for the HDI sensor, two connection terminals 50 (A) for the assist element (high-frequency assist element or thermal assist element), two connection terminals 50 (H) for the heater, two connection terminals 50 (W) for the light head, and finally, one connection terminal 50 (G) for the gimbal micro actuator (GMA) (piezoelectric element 53) are arranged in this order. That is, the connection terminals 50 (A) for the assist element are arranged at the center (the 6th and 7th from the base end side) in the arrangement direction, the connection terminals 50 (W) for the light head are arranged on the base end side of the connection end portion 48c, and the connection terminals 50 (H) for the heater are provided between the connection terminals 50 (A) for the assist element and the connection terminals 50 (W) for the light head. The connection terminals 50 (R) for the lead head are arranged on the tip side of the connection end portion 48c, and the connection terminals 50 (S) for the HDI sensor are provided between the connection terminals 50 (A) for the assist element and the connection terminals 50 (R) for the lead head. According to the above-described array, the intervals between the connection terminal 50(W) for the write head and the connection terminal 50(A) for the assist element, and between the connection terminal 50(R) for the read head and the connection terminal 50(A) for the assist element can be widened, and crosstalk between the terminals during driving can be prevented. Further, by providing the connection terminal 50(W) for the write head at the base end portion of the connection end portion 48c, the length of the wiring between the connection terminal 50(W) and the magnetic head 17 can be made shortest, and the impedance of the wiring can be reduced. Note that the array of the connection terminals 50 is not limited to the above-described array, and in order to avoid crosstalk, an array in which the connection terminal for the write head and the connection terminal for the read head are not adjacent to the connection terminal for the assist element may be used.

[0031] As shown in FIGS. 7 and 8, the base insulating layer 86a covering the connection terminals 50 and the wiring S has a plurality of first openings OP1 and a plurality of second openings OP2 arranged in the longitudinal direction of the connection end portion 48c. The plurality of first openings OP1 are provided at positions facing the connection terminals 50, respectively. The plurality of second openings OP2 are provided at positions facing the space portions between the connection terminals 50, respectively. As shown in FIG. 8, the first opening OP1 faces the through hole 50a of the connection terminal 50. The width W4 of the first opening OP1 is larger than the width W3 of the through hole 50a and smaller than the width WT of the connection terminal 50. In the longitudinal direction of the opening 90, the side edge of the first opening OP1 is located between the side edge (periphery) of the through hole 50a and the side edge of the connection terminal 50. In the width direction of the opening 90, the length of the first opening OP1 is longer than the length of the through hole 50a and shorter than the length of the connection terminal 50 (width W2 of the opening 90). In the first opening OP1, the regions (both end portions) located outside the through hole 50a in the longitudinal direction gradually become narrower toward the base end side of the connection terminal 50.

[0032] The plurality of second openings OP2 face, respectively, the space between two adjacent connection terminals 50 and the spaces between one longitudinal end and the other longitudinal end of the opening 90 and the connection terminals 50. Each second opening OP2 has a substantially rectangular shape corresponding to the shape of the space. The width W5 of the second opening OP2 is smaller than the width WS of the space, and the length of the second opening OP2 is smaller than the width W2 of the opening 90. As a result, the periphery of the second opening OP2 is slightly spaced apart from the side edges of the connection terminal 50 and the side edges of the opening 90. In the longitudinal direction of the opening 90, the side edges of each connection terminal 50 are located between the side edge of the first opening OP1 and the side edge of the second opening OP2.

[0033] FIG. 9 is a cross-sectional view of the connection end portion along line A-A of FIG. 8, and FIG. 10 is a cross-sectional view of the connection end portion along line B-B of FIG. 8. As shown in the figure, both side edge portions of each connection terminal 50 are covered with the base insulating layer 86a. Also, both longitudinal end portions of each connection terminal 50, that is, the base portions on both sides, are covered with the base insulating layer 86a. The through hole 50a of the connection terminal 50 opens to the first opening OP1 and the opening 90. The second opening OP2 of the base insulating layer 86a opens to the opening 90 of the cover insulating layer 86c. According to the above configuration, the peripheral portion of each connection terminal 50 is covered with the base insulating layer 86a and supported by the base insulating layer 86. Therefore, even when the film thickness of the conductive layer (copper foil) forming the connection terminal 50 is reduced, it is possible to maintain the rigidity of the connection terminal 50.

[0034] FIG. 11(a) is a cross-sectional view showing a state in which the connection end portion 48c of the flexible printed circuit is disposed overlapping the connection pad group 72 of the joint portion 64, and FIG. 11(b) is a cross-sectional view of the connection end portion and the joint portion joined by solder. When the connection end portion 48c of the flexible printed circuit 48 configured as described above is soldered to the joint portion 64 of the FPC unit, as shown in FIG. 11(a), the connection end portion 48c is disposed overlapping the connection pad group 72 of the joint portion 64. The connection end portion 48c is disposed with the cover insulating layer 68c facing the joint portion 64. The 13 connection terminals 50 are disposed overlapping the corresponding connection pads 73 and the solder layer 78 of the joint portion 64 through the opening 90.

[0035] In this state, laser light is irradiated onto the connection end portion 48c and the joint portion 64 from the side of the connection end portion 48c. The laser light is irradiated onto the connection terminal 50 and the solder layer 78 through the first opening OP1 of the connection end portion 48c. The connection terminal 50 and the solder layer 78 directly absorb heat, melting the solder layer 78, and the connection terminal 50 and the connection pad 73 are solder-joined. At the same time, the laser light is irradiated onto the joint portion (FPC) 64 through the second opening OP2 and the opening 90 of the connection end portion 48c, and the joint portion 64 is heated. The heat of the joint portion 64 is transmitted to the solder layer 78 through the connection pad 73, contributing to the melting of the solder layer 78. As shown in FIG. 11(b), the melted solder layer 78 spreads over the surface of the connection terminal 50 on the side of the cover insulating layer 68c and flows into the first opening OP1 through the through-hole 50a of the connection terminal 50, and is also joined to the surface on the opposite side of the connection terminal 50. Thereby, the connection terminal 50 and the connection pad 73 are electrically and mechanically joined by the solder layer 78, ensuring conductivity between them.

[0036] As shown in FIG. 1, in a state where the actuator assembly 22 and the FPC unit 21 configured as described above are incorporated into the base 12, the actuator assembly 22 is rotatably supported around the support shaft 26. Each magnetic disk 18 is positioned between two suspension assemblies 30. During the operation of the HDD, the magnetic head 17 attached to the suspension assembly 30 faces the upper and lower surfaces of the magnetic disk 18, respectively. The base portion 60 of the FPC unit 21 is fixed to the bottom wall 12a of the base 12.

[0037] According to the HDD and the suspension assembly configured as described above, at the connection end portion 48c of the flexure 48, the peripheral portions of the respective connection terminals 50 are covered and supported by the base insulating layer 68a. Therefore, even when the film thickness of the conductive layer (copper foil) forming the connection terminal 50 is reduced, the strength and rigidity of the connection terminal 50 can be maintained, and bending or the like of the connection terminal during the manufacturing process can be prevented. And by reducing the film thickness of the conductive layer, it becomes possible to make the pitch of the wiring S formed by the conductive layer narrower. By reducing the wiring pitch, the width W1 of the connection end portion 48c can be reduced, and the flexure 48 and the connection end portion 48c can be miniaturized. Further, in the present embodiment, at the connection end portion 48c, by narrowing the widths of both ends of the first opening OP1, both root portions of the connection terminal are covered with the base insulating layer 68a over a wide range. Therefore, the strength and rigidity of the connection terminal can be efficiently improved.

[0038] Furthermore, at the connection end portion 48c, the base insulating layer 68a is configured to have a plurality of second openings OP2 facing the space portions between the connection terminals. Therefore, when joining the connection end portion 48c, it becomes possible to apply laser light to the joint portion 64 of the FPC through the second openings OP2, and the melting of the solder layer can be promoted by the heat generation of the joint portion 64. Thereby, insufficient melting and non-adhesion of the solder can be eliminated, and the reliability of the connection of the connection terminal can be improved. From the above, according to the present embodiment, a suspension assembly capable of achieving narrow pitch of wiring and improved joinability of connection terminals while maintaining the strength of the connection terminals, and a disk device including the same can be obtained.

[0039] Next, the HDD and the suspension assembly according to another embodiment will be described. In the other embodiments described below, the same parts as those in the above-described first embodiment are denoted by the same reference numerals, and the detailed description thereof is omitted or simplified, and the description will be centered on the parts different from the first embodiment. (Second Embodiment) FIG. 12(a) is a plan view showing a part of the joint portion 64 of the FPC in the HDD according to the second embodiment, and FIG. 12(b) is a cross-sectional view showing a state where the connection end portion 48c of the flexure is disposed overlapping the connection pad group 72 of the joint portion 64. As shown in the figure, according to the second embodiment, each connection pad 73 of the joint portion 64 integrally has an extension portion 73a that extends to a position facing the second opening OP2 of the connection end portion 48c. A resin layer (insulating layer) 88 such as polyimide is provided so as to overlap the extension portion 73a and the joint portion 64. The resin layer 88 faces the second opening OP2.

[0040] As shown in FIG. 12(b), when laser irradiation is performed during joining, the laser light is irradiated to the connection terminal 50 and the solder layer 78 through the first opening OP1 of the connection end portion 48c. The solder layer 78 melts by directly absorbing heat from the connection terminal 50 and the solder layer 78, and the connection terminal 50 and the connection pad 73 are solder-joined. At the same time, the laser light is irradiated to the resin layer 88 of the joint portion (FPC) 64 through the second opening OP2 and the opening 90 of the connection end portion 48c, and the resin layer 88 absorbs the heat. The heat of the resin layer 88 is transmitted to the solder layer 78 through the connection pad 73, contributing to the melting of the solder layer 78. Thereby, it becomes possible to further improve the meltability of the solder. In the second embodiment, the other configurations of the connection end portion 48c and the joint portion 64 are the same as those of the connection end portion and the joint portion in the first embodiment described above. Also in the second embodiment, the same operational effects as those of the first embodiment described above can be obtained.

[0041] (Third Embodiment) FIG. 13 is an enlarged plan view showing a part of the connection end portion of the flexure in the HDD according to the third embodiment. As shown in the figure, according to the third embodiment, both side edges of the connection terminal 50 and both side edges of the through hole 50a are not straight lines, but have arc-shaped convex portions 50b and 51a protruding toward the side of the second opening OP2, respectively. The convex portion 50b is located approximately at the center in the longitudinal direction of the side edge of the through hole 50a, and extends beyond the side edge of the first opening OP1 toward the side of the second opening OP2. Similarly, the convex portion 51a is located approximately at the center in the longitudinal direction of the side edge of the connection terminal 50 and faces the convex portion 50b in the width direction. The convex portions 50b and 51a are covered with the base insulating layer 68a.

[0042] As described above, by providing the convex portions 50b and 51a on the side edges of the through hole 50a and the side edge of the connection terminal 50, respectively, while maintaining the rigidity of the connection terminal 50, the area of the through hole 50a can be increased, and the contact area between the connection terminal 50 and the solder can be increased. Thereby, it becomes possible to improve the bonding strength of the solder to the connection terminal 50. In the third embodiment, other configurations of the connection end portion 48c are common to the connection end portion in the first embodiment described above. Also in the third embodiment, the same operational effects as those in the first embodiment described above can be obtained.

[0043] (Fourth Embodiment) FIG. 14 is a plan view of the connection end portion of the flexure in the HDD according to the fourth embodiment. According to the fourth embodiment, the connection end portion 48c has a configuration including 14 connection terminals 50. As shown in the figure, the cover insulating layer has, for example, an opening 90 with a length L2 of about 6 mm and a width W2 of 0.5 mm. The 14 connection terminals 50 are respectively arranged to face the opening 90 and are arranged at intervals in the longitudinal direction of the opening 90. The width WT of each connection terminal 50 is set to 0.2 mm as in the first embodiment. In this embodiment, one connection terminal 50 (G) for the micro actuator (piezoelectric element) is added. This connection terminal 50 (G) is arranged at the most proximal end of the opening 90. The arrangement of the other 13 connection terminals 50 is set in the same manner as in the first embodiment.

[0044] In one example, from the extending end side of the connection end portion 48c, four connection terminals 50(R) for the lead head, two connection terminals 50(S) for the HDI sensor, two connection terminals 50(A) for the assist element (high-frequency assist element or thermal assist element), two connection terminals 50(H) for the heater, two connection terminals 50(W) for the light head, and finally, two connection terminals 50(G) for the gimbal micro actuator (GMA) (piezoelectric element 53) are arranged in this order. The connection terminals 50(A) for the assist element are arranged at the central portion (the 6th and 7th from the base end side) in the arrangement direction. The connection terminals 50(W) for the light head are arranged on the base end side of the connection end portion 48c, and the connection terminals 50(H) for the heater are provided between the connection terminals 50(A) for the assist element and the connection terminals 50(W) for the light head. The connection terminals 50(R) for the lead head are arranged on the tip end side of the connection end portion 48c, and the connection terminals 50(S) for the HDI sensor are provided between the connection terminals 50(A) for the assist element and the connection terminals 50(R) for the lead head.

[0045] The base insulating layer 86a covering the connection terminals 50 and the wiring S has a plurality of first openings OP1 and a plurality of second openings OP2 arranged in the longitudinal direction of the connection end portion 48c. The plurality of first openings OP1 are provided at positions facing the 14 connection terminals 50 respectively. The plurality of second openings OP2 are provided at positions facing the space portions between the connection terminals 50 and the space portions between one end and the other end in the longitudinal direction of the opening 90 and the connection terminals respectively. In the fourth embodiment, the other configuration of the connection end portion 48c is the same as the configuration of the connection end portion 48c in the first embodiment. Even in the fourth embodiment having 14 connection terminals, the same operational effects as those of the first embodiment described above can be obtained.

[0046] The present invention is not limited to the above-described embodiments as they are, and at the implementation stage, components can be modified and embodied without departing from the gist thereof. Also, various inventions can be formed by appropriately combining a plurality of components disclosed in the above-described embodiments. For example, some components may be deleted from all the components shown in the embodiments. Furthermore, components from different embodiments may be appropriately combined. The magnetic disks are not limited to five, and may be four or less or six or more, and the number of suspension assemblies and the number of magnetic heads may be increased or decreased according to the number of magnetic disks installed. At the connection end of the suspension assembly, the shape, size of the connection terminal, and the shape, size, etc. of the first opening and the second opening are not limited to those in the above-described embodiments, and can be variously changed as required. The type and function of the connection terminal are not limited to those in the above-described embodiments, and can be variously changed according to the functions of the magnetic head and the suspension assembly.

Description of Signs

[0047] 10... housing, 12... base, 12a... bottom wall, 12b... side wall, 14... top cover, 18... magnetic disk, 17... magnetic head, 19... spindle motor, 21... FPC unit, 22... actuator assembly, 30... suspension assembly, 48... flexure (wiring member), 48c... connection end (tail connection end), 50... connection terminal, 64... joint, 68a... base insulating layer, 68b... conductive layer, 68c... cover insulating layer, 72... connection pad group, 73... connection pad, 90... opening, OP1... first opening, OP2... second opening

Claims

1. A support plate, a head supported by the support plate, and a wiring member installed on the support plate, comprising: The wiring member has a tip electrically connected to the head, a connection end extending outside the support plate, and a plurality of wirings extending between the tip and the connection end ; The connection end includes a cover layer provided with an opening having a predetermined length, and 13 or more connection terminals arranged side by side at intervals in the length direction of the opening and each connected to the wiring, and a base layer provided on top of the cover layer and the connection terminals and having a plurality of first openings each facing a part of a connection terminal and a plurality of second openings each facing a space between adjacent connection terminals; A suspension assembly.

2. The suspension assembly according to claim 1, wherein the connection terminal has a through hole opening to the opening of the cover layer and the first opening.

3. The connection terminal has a pair of side edges facing each other at intervals in the length direction of the opening, the through hole has a peripheral edge located between the pair of side edges, and the first opening is an opening larger than the through hole and has a pair of side edges respectively located between the side edge of the connection terminal and the peripheral edge of the through hole. The suspension assembly according to claim 2.

4. The suspension assembly according to claim 3, wherein the second opening has a peripheral edge adjacent to and spaced from the side edge of the connection terminal and the side edge of the opening of the cover layer.

5. The first opening has both ends facing the root portion of the connection terminal respectively, and the both ends are narrower in width toward the root of the connection terminal respectively. The suspension assembly according to claim 3.

6. The side edge of the connection terminal and the peripheral edge of the through hole each have a convex portion protruding toward the side of the second opening OP2. The suspension assembly according to claim 3.

7. The convex portion of the peripheral edge of the through hole protrudes toward the side of the second opening beyond the side edge of the first opening. The suspension assembly according to claim 6.

8. The 13 or more connection terminals include a plurality of connection terminals for a light head, a plurality of connection terminals for a read head, a plurality of connection terminals for an assist element, a plurality of connection terminals for a heater, a connection terminal for an HDI sensor, and a connection terminal for a micro actuator. Between the connection terminal for the assist element and the connection terminal for the read head, the connection terminal for the HDI sensor or the connection terminal for the heater is disposed. The suspension assembly according to claim 1, wherein between the connection terminal for the assist element and the connection terminal for the light head, the connection terminal for the HDI sensor or the connection terminal for the heater is disposed.

9. A disk-shaped recording medium having a recording layer; A rotatable actuator block, a plurality of arms extending from the actuator block, a circuit board having a plurality of connection pads arranged side by side and provided so as to overlap the installation surface of the actuator block, solders respectively provided on the connection pads, and the suspension assembly according to claim 1 respectively fixed to the arms, a head actuator comprising: The connection end portion of the wiring member is disposed on the circuit board so as to overlap the connection pad and the solder, and the plurality of connection terminals are joined to the connection pad by the solder. A disk device.

10. Each connection pad of the circuit board has an extension portion facing the second opening of the connection end portion. The disk device according to claim 9, wherein the circuit board has a resin layer provided so as to overlap the extension portion and facing the second opening.

Images