Patent Abstract:
Embodiments of the invention provide a head/slider supporting structure which has connection properties excellent in solder ball connections of a slider pad and a lead pad. According to one embodiment, in a head/slider supporting structure for connecting a slider and a lead wire by re-flowing a solder ball, a connection distance between a slider pad and an extreme end portion of the lead wire is reduced to enhance the performance of solder connection. The lead wire is inclined forwardly of the slider pad.

Full Description:
CROSS-REFERENCES TO RELATED APPLICATIONS 
     This application claims priority from Japanese Patent Application No. JP2004-058021, filed Mar. 2, 2004, the entire disclosure of which is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to the technique for solder-connecting a head provided on a slider of a magnetic disk drive, a magneto-optical disk drive or the like and a lead wire connected to a circuit base plate, and more specifically, to the technique for enhancing the positive properties of connection between a slider pad and a lead wire using a solder ball. 
     In the magnetic disk drive, a head for converting a magnetic signal to an electric signal carries out writing or reading of data with respect to the magnetic disk. A head and a slider constitute a head/slider, and a supporting structure called a suspension assembly supports the head/slider. The head/slider flies, in reading or writing data, above the magnetic disk which rotates at high speed while performing track following operation called pitch and roll movement or gimbals movement. 
     A semiconductor chip for carrying out control and data transfer of the magnetic disk drive is mounted on the circuit base plate, and it is necessary to electrically connect the head and the circuit base plate of the magnetic disk drive by means of a lead wire. Recently, as recording density enhances, demand of the head with respect to the control characteristics becomes severe, influence of weight, arrangement and the like of the lead wire on positional control of the head cannot be ignored. As a result, there is a tendency that a wiring integrated type flexure assembly is employed in which a wiring is adhered to or a wiring pattern is formed on the flexure to reduce unbalance given by the wiring to the gimbals characteristics of flexure. In the wiring integral type flexure assembly, the sliding pad connected to the head need be connected electrically to the end of the lead wire. As one connecting method, there is a supersonic adhesion method as shown in Japanese Patent Laid-Open No. Hei 11-96710. In this method, the end of the lead wire is placed on the slider pad to provide connection while giving vibrations to a gold ball by means of a bonding tool. Recently, the magnetic disk drive is further miniaturized, the slider is also miniaturized, and the gimbals movement is made finer, because of which it becomes necessary to reduce the stress as much as possible on the slider or the lead wire when the lead wire is connected. Further, in the supersonic adhesion method, there is a fear that static electricity generated in the course of adhesion is discharged to break the slider or the head, and there is pointed out limitation as the adhesion method for further miniaturized head/slider. 
     As another method for connecting the head/slider and the lead wire, there exists a solder ball adhesion method capable of connecting with respect to a connection portion in non-contact. Japanese Patent Laid-Open No. 2002-251705 discloses the technique regarding the slider ball adhesion method.  FIGS. 4 and 5  of that patent reference show a method in which the bonding pad and lead pad provided on the slider are arranged at right angles, the spherical solder ball is temporarily fixed so as to come in contact with both the pads, and afterward, the solder allows re-flow by a laser beam to provide solder connection. Further, Patent Japanese Patent Laid-Open No. 2003-123217 likewise relates to the solder ball connection, and  FIGS. 4 and 5  and the description of that patent reference clearly describes that an angle between the head pad and the lead pad is 90 degrees. 
     In U.S. Pat. No. 5,896,247, the prior art with respect to the invention of Patent Document 4 is described referring to  FIG. 5  thereof. In the description of  FIG. 5  in that patent document, there is described that prior to mounting the slider, the flexure tang mounting the slider and the support layer are at the same level. Further, there is described that it is necessary to extend the dielectric layer toward the slider from the copper trace in order to eliminate possible short-circuiting trouble, and as a result, the slider is mounted on the flexure tang, and during the copper trace and the transducer pad are connected by solder ball or gold ball, the dielectric layer has to be pressed down by the thickness of the dielectric layer under the slider. 
     BRIEF SUMMARY OF THE INVENTION 
       FIG. 1  is a view explaining the state that the lead pad and the slider pad are subjected to solder ball connection.  FIG. 1(A)  shows metallic layers  19   a ,  19   b  constituting a supporting structure of flexure, dielectric layers  17   a ,  17   b  laminated on the metallic layers  19   a ,  19   b , and a copper layer  21  laminated on the dielectric layer  17   b  so as to constitute a lead wire. A slider  11  is mounted on the dielectric layer  17   a , and a slider pad  13  connected to a head not shown is provided on the slider  11 . The metallic layer  19   a  supporting the slider  11  conducts gimbals movement with a dimple formed on a load beam (not shown) called a flexure tang, as a supporting point. 
     On the front surface of the slider pad  13 , a lead wire  21  extends to a position leaving a space  25  with respect to the slider  11 , and a lead pad  29  is formed at the extreme end portion of the lead wire  21 . When a spherical solder ball  15  is temporarily fixed so as to come in contact with the slider pad  13  and the lead pad  29 , and a laser beam is irradiated from the direction indicated by arrow A, the solder ball  15  becomes fused. After that, when the irradiation of the laser beam is stopped to let leaving and cooling, a solder fillet  27  shown in  FIG. 1(B)  is formed whereby both the pads can be electrically connected. In the solder ball connection, when the solder ball  15  is allowed to re-flow, inferior connections sometimes occur such that the fused solder is strongly attracted by one of the pads so that the solder fillet  27  is not connected to the other pad; a contact area between the solder fillet  27  and the pad is short; the connection strength is short; or short-circuiting with the adjacent pad. 
     During the course of studying the measures for the inferior connections, we found that an effective method for carrying out the adequate solder ball connection is, in addition to an improvement of solder wetting properties of the pad or improvement of material of solder, to shorten a connection distance  23  between the slider pad  13  and the lead pad  29 . The connection distance  23  is a shortest distance between the extreme end portion of the lead pad  29  and the end of the slider pad  13 . To shorten the connection distance  23 , there is a method for moving the lead wire  21  closer to the slider  11  to thereby narrow the space  25  and shorten the horizontal distance, which however has a limit in terms of securing a positional tolerance when the slider  11  is fixed to the dielectric layer  17   a.    
     Next, where the vertical distance between both the pads is intended to be shortened, the flexure has been heretofore designed so that the surface including the slider pad  13  and the surface including the lead pad  29  cross at right angles, because of which it is necessary to change it, as shown in Japanese Patent Laid-Open No. 2002-251705 or Japanese Patent Laid-Open No. 2003-123217 also. The reason why they are crossed at right angles seems to lie in that generally, in the wiring integral flexure structure employing the solder ball connection, the metallic layer  19   b  supporting the lead pad  29  and the metallic layer  19   a  supporting the slider  11  are formed to be the same plane using the same material in the same process, and the plane structure has been maintained except for special reasons. 
     Further, the above reason seems to lie in that since the flexure is the structure for carrying out the fine gimbals movement, a displacing portion or a bending portion is provided on the metallic layers  19   a ,  19   b  so as to avoid changing the operating characteristics. Further, the above reason seems to lie in that as shown in Japanese Patent Laid-Open No. 2002-251705, in the solder connection, the slider pad and the lead pad are set to a connection device so as to each open at 45 degrees with respect to the vertical direction, allowing the supplying work or fixing work of the solder ball to be smoothly conducted, and making it convenient. Therefore, the connection distance between the surface including the slider pad  13  and the surface including the lead pad  29  has been determined so far as in the structure shown in  FIG. 1 . 
     In U.S. Pat. No. 5,896,247,  FIG. 5  shows the state that a support layer is inclined toward a transducer pad. However, since the amount of inclination is, say, about the thickness of the dielectric layer, it is said that substantially, the extending surface of the transducer pad and the extending surface of the copper trace cross at right angles. Therefore, the connection distance  23  is determined according to the distance B between the bottom of the slider pad  13  provided on the side of the slider  11  and the bottom of the slider  11 , and the width of the space  25  provided between the lead wire  21  and the slider  11 . As described above, there is a limit in narrowing the space  25 , and the distance B also need to have a predetermined length in order to prevent short-circuiting between the metallic layer  19   a  and the slider pad  13  due to the solder ball connection. 
     It is therefore a feature of the present invention to provide a head/slider supporting structure provided, in a solder ball connection of a slider pad and a lead pad, with an excellent connection performance. A further feature of the present invention is to provide a rotating disk storage device having head/slider supporting structure with excellent connection performance. 
     In a head/slider supporting structure for solder ball connecting a slider and a lead wire, according to a feature of the invention, a connection distance between an end of a slider pad and an extreme end portion of a lead wire is shortened to thereby enhance the performance of solder connection. 
     According to a first aspect of the present invention, a head/slider supporting structure comprises a slider supporting portion; a head/slider having a bottom secured to said slider supporting portion, and including a head and a slider pad connected to said head; and a lead wire capable of being solder ball connection to said slider pad; wherein a plane including an extreme end portion of said lead wire and a plane including said slider pad cross each other at a crossing angle less than 90 degrees on a surface on which said solder ball is arranged. 
     Since the plane including an extreme end portion of the lead wire and the plane including the slider pad cross each other at a crossing angle less than 90 degrees on a surface on which the solder ball is arranged, the connection distance therebetween can be reduced so that both the planes can securely be connected to each other when the solder ball is allowed to re-flow. When the crossing angle is made to be about 70 to 80 degrees, a relation between the size of the solder ball and the connection distance becomes appropriate. The extreme end portion of the lead wire is a part that is electrically connected to the slider pad, and a pad for fixing a solder ball may be suitably formed. 
     When the solder ball connection is applied to a wiring integral flexure assembly employed as the head/slider supporting structure adapted to high-density recording, it will be effective because no electrostatic breakdown occurs in the head or no extra stress is applied to the structure. The wiring integral flexure assembly includes a lamination structure of a metallic layer, a conductor layer forming a lead wire, and a dielectric layer insulating the metallic layer from the conductor layer. In addition, the extreme end portion of the lead wire can be separated from the dielectric layer to form a bending crossing angle. Further, the extreme end portion of the lead wire can be made integral with the dielectric layer, which is separated from the metallic layer and bended to form a crossing angle. Alternatively, the metallic layer, the dielectric layer and the conductor layer can be made to be integral and inclined to form a crossing angle. Further, alternatively, one of or both the metallic layer and the dielectric layer located under the extreme end portion of the lead wire may be laminated thicker than other portions so that the extreme end portion of the lead wire may be inclined. 
     The dielectric layer laminated on the platform of the metallic layer provided forwardly of the slider pad extends toward the slider pad beyond the end of the platform whereby it is possible to prevent the conductor layer from short-circuiting with the metallic layer in the solder ball connection. Further, the conductor layer extends toward the slider pad beyond the end of the dielectric layer whereby the dielectric layer can be prevented from burning when a laser beam is irradiated. 
     According to a second aspect of the present invention, a head/slider supporting structure comprises a slider supporting portion; a head/slider having a bottom secured to said slider supporting portion, and including a head and a slider pad connected to said head; and a lead wire capable of being solder ball connection to said slider pad; wherein a plane including an extreme end portion of said lead wire and said slider pad cross each other at a crossing angle above 90 degrees on a surface on which said solder ball is arranged. 
     In the second aspect, the lead wire is inclined in a direction different from that of the first aspect with respect to the slider pad to thereby shorten the connection distance. The crossing angle may be any angle over 90 degrees, preferably, in the range of about 100 to 120 degrees. 
     According to a third aspect of the present invention, a head/slider supporting structure comprises a slider supporting portion; a head/slider having a bottom secured to said slider supporting portion, and including a head and a slider pad connected to said head; and a lead wire capable of being solder ball connection to said slider pad; wherein a plane including an extreme end portion of said lead wire crosses said slide pad at a right angle. 
     In the third aspect, the lead wire is directed at a right angle with respect to the slider pad. However, since the plane including the lead wire crosses the slider pad, the connection distance can be made shorter than the conventional connection structure. Any of the first to third modes can be applied to the rotating disk storage device such as the magnetic disk drive, and the magneto-optical disk drive. Further, the rotating direction of the rotating disk storage device may be not only the positive direction but also the reverse direction. 
     According to the present invention, it is possible to provide a head/slider supporting structure having connection performance excellent in a solder ball connection of a slider pad and a lead pad. Further, according to the present invention it is possible to provide a rotating disk storage device provided with the head/slider supporting structure excellent in connection performance. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIGS. 1(A) and 1(B)  are views explaining the state when a lead pad and a head pad are connected by a solder ball. 
         FIG. 2  is a plan view of a magnetic disk drive according to an embodiment of the present invention. 
         FIG. 3  is a view explaining the structure of a head suspension assembly according to an embodiment of the present invention. 
         FIGS. 4(A) and 4(B)  are views explaining the structure of a flexure assembly  100 . 
         FIGS. 5(A) to 5(E)  are views explaining the structure of a flexure assembly  100 . 
         FIG. 6  is a view with the flexure assembly  100  shown in  FIG. 5(A)  enlarged. 
         FIG. 7  is a side view for explaining an embodiment of a connection structure of a head/slider and a lead wire. 
         FIGS. 8(A) and 8(B)  are side views for explaining another embodiment of a connection structure of a head/slider and a lead wire. 
         FIG. 9  is a side view for explaining another embodiment of a connection structure of a head/slider and a lead wire. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     In the following, the embodiments of the present invention will be described with reference to the drawings. The same reference numerals denote the same structural elements throughout the drawings.  FIG. 2  is a plan view showing the schematic structure of a magnetic disk drive  50  applied to the embodiments of the present invention. A base  52  forms a closed space together with a cover (not shown), and encases therein an actuator head suspension assembly  54 , a magnetic disk  66 , a ramp  64 , and a semiconductor element  71  and the like. 
     The magnetic disk  66  is fixed to a spindle hub (not shown) so as to be rotated about a spindle shaft  68  by a spindle motor (not shown) provided below, and it has a magnetic layer formed at least on one surface thereof. Two magnetic disks  66  or more may also be stacked. With respect to the direction in which the magnetic disk  66  is rotated, the arrow A is called positive rotation and the arrow B is called reverse rotation in relation to the actuator head suspension assembly  54 . The difference between the positive rotation and the reverse rotation mainly appears at a position of the head of the slider, but the present invention can be applied to the magnetic disk drives for both positive rotation and reverse rotation. 
     The actuator head suspension assembly  54  includes an actuator assembly  57  and a head suspension assembly  62  so that it may be pivoted about a pivot point  58 . The actuator assembly  57  includes an actuator arm  56  mounting a head suspension assembly  62  thereon, a coil support  59  holding a voice coil (not shown), and a pivot housing corresponding to a communication portion between the actuator arm  56  and the coil support  59 . A voice coil yoke  60  is provided on the base so as to constitute a voice coil motor along with the voice coil, and a voice coil magnet (not shown) or a permanent magnet is mounted on the back of the voice coil yoke  60 . 
     The head suspension assembly  62  includes a load beam and a flexure (both of which are not shown) described in detail later. The so-called load/unload system is formed in which a merge lip  70  is formed at the extreme end of the load beam, and before the magnetic disk  66  stops its rotation, the merge lip  70  is slidably moved on the sheltering surface of the ramp  64  to retract the slider from the surface of the magnetic disk  66 . However, the present invention is not limited to the application to the load/unload system, but can be also applied to the contact start stop system. The merge lip  70 , the head suspension assembly  62  and the actuator arm  56  are formed as a lamination structure so as to accommodate the recording surface of the magnetic disk  66 . A relay terminal  73  is provided on the actuator assembly  57  to connect a wiring trace (not shown) with one end connected to the head, and a flexible print circuit base plate  74  with one end connected to a semiconductor element  71 . 
       FIG. 3  is a perspective view explaining the structure of the head suspension assembly  62  according to the embodiment of the present invention. The head suspension assembly  62  includes a mount plate  79 , two pieces of load beams  75   a ,  75   b , a hinge  77 , and a flexure assembly  100 . The flexure assembly  100  employs a wiring integral structure and has a wiring trace  105  as described later. In a flexure tang (not shown) of the flexure assembly  100 , head/sliders  103  are mounted on both sides facing to the magnetic disk  66 . 
     The flexure assembly  100  is fixed to the load beams  75   a ,  75   b  and the hinge  77  by spot welding or adhesives, and the mount plate  79  and the load beams  75   a ,  75   b  and the hinge  77  are also fixed integrally by spot welding or adhesives. The mount plate  79  is subjected to swath processing to fix the head suspension assembly  62  to the actuator arm  56 . The load beams  75   a ,  75   b  rotate along with the actuator assembly  57  to carry the head/slider  103  to a fixed track and supply a pressing load for pressing the head/slider  103  on the surface of the magnetic disk  66 . The head/slider  103  flies above while maintaining a certain distance from the surface of the magnetic disk  66  which rotates under the balance between the positive pressure which is a floating force received by an air bearing surface from an air flow and a pressing load caused by the load beam  75 . 
     The wiring trace  105  has one end connected to the slider pad (not shown) and the other end connected to a relay terminal  73 . The wiring integral flexure assembly generally has a metallic layer as a structure for supporting the head/slider and carrying out the gimbals movement, a conductor layer constituting a wiring trace, and a dielectric layer insulating the metallic layer and the conductor layer laminated, and provides a suitable cover layer on the conductor layer for preventing corrosion or applies plate treatment. The wiring integral flexure assembly provided with the lamination structure as described includes three types, that is, an additive type, a subtractive type, and a flexible base plate type depending on the difference of a manufacturing method. 
     The additive type is a method for stacking up layers in order using the photolithography technique. The subtractive type is a method for applying etching to a sheet formed in advance with a metallic layer, a dielectric layer, a conductor layer and a cover layer to form a fixed structure. The flexible base plate type is a method for pasting on the metallic layer the flexible print circuit base plate formed into a fixed shape by the dielectric layer, the conductor layer and the cover layer. The flexure assembly  100  according to the present embodiment is of the additive type, but the present invention can be applied to any type of wiring integral flexure assemblies. Further, the present invention is not limited to the wiring integral flexure assembly, but can be applied to all types of flexure assemblies in which the slider pad and the lead pad are connected by solder ball. 
       FIGS. 4 and 5  are views explaining the structure of the wiring integral flexure assembly  100 .  FIG. 4(A)  is a plan view of the flexure assembly  100  shown in  FIG. 3  enlarged from the top of the load beam, and  FIG. 4(B)  is a plan view from the bottom.  FIG. 4(B)  shows various welding spots illustrating positions of spot welding for assembling the flexure assembly.  FIG. 4(B)  shows a flexure tang  101  which is a place where the head/slider  103  is mounted. The flexure assembly  100  is fixed to the load beam  75   a  at three locations of welding spots  112   a ,  112   b  and  112   c , and the flexure tang  101  is not fixed to the load beam  75   a  in order to enable the gimbals movement. 
       FIG. 5  is a view showing the lamination structure of the wiring integral flexure assembly  100  shown in  FIG. 4 . The flexure assembly  100  is formed using the semiconductor processing technique such as the photolithographic etching step, the evaporation step or the like as mentioned above.  FIG. 5(A)  shows the flexure assembly  100  completed by laminating a plurality of layers, and  FIGS. 5(B) to 5(E)  show the structure of layers constituting the flexure assembly  100 .  FIG. 5(A)  is a view showing the completed flexure assembly  100  from the magnetic disk  66  side, the head/slider  103  being omitted for simplicity&#39;s sake.  FIGS. 5(B) to 5(E)  depict the order of lamination toward the surface of the magnetic disk. 
       FIG. 5(B)  shows a plane of a metallic layer  111 , and as a material, there is selected SUS304 having a thickness of 0.02 mm among stainless steel of 300 series. Further, the material of the metallic layer  111  is not limited to stainless steel, but other hard spring materials such as beryllium copper or titanium can be selected. The metallic layer  111  includes a flexure tang  101  and a platform  214 . 
       FIG. 5(C)  shows a plane of a dielectric layer  113  formed of polyimide for insulating the metallic layer  111  and a conductor layer  115  (see  FIG. 7(D) ). The dielectric layer  113  is laminated on the metallic layer  111  in the shape adjusted to a pattern of the conductor layer  115 . In the present embodiment, the thickness of the dielectric layer selected is 0.01 mm. A part of the dielectric layer  113  is laminated also on the flexure tang  101 . 
       FIG. 5(D)  shows a conductor layer  115  which is a wiring pattern with respect to a head. In the present embodiment, pure copper is laminated so as to have a thickness of 0.01 mm into pattern. The material of the conductor layer is not limited to copper, but other material such as aluminum or silver may be employed.  FIG. 5(E)  shows a pattern of a cover layer  117  for protecting the surface of the conductor layer  115 , and a polyimide layer having a thickness of about 0.003 mm is adhered to the conductor layer  115 . The dielectric layer  113 , the conductor layer  115  and the cover layer  117  are integrated to form a wiring trace  105 . Thicknesses of the metallic layer  111 , the dielectric layer  113 , the conductor layer  115  and the cover layer  117  are indicated as an illustration, and the range of the present invention is not limited thereto. 
       FIG. 6  is a view in which the extreme end portion of the flexure assembly  100  shown in  FIG. 5  is enlarged. In the present disclosure, the merge lip  70  side of the head suspension assembly  62  is referred to as the extreme end side, and the actuator arm  56  side is referred to as the support end side (see  FIG. 2 ). The flexure tang  101  which is a part of the metallic layer  111  is formed between a welding spot  112   a  on the extreme end side of the flexure assembly  100  and a welding spot  112   b  on the support end side. In the flexure tang  101 , there is defined a dimple contact point (hereinafter referred to as DCP)  205  on the center line joining the welding spots  112   a  and  112   b  and nearly in the central portion of the flexure tang  101 . In the DCP  205 , the flexure tang comes in contact, at the back (corresponding to the back of paper surface), with a dimple formed on the load beam  75   a  to constitute a support point of the gimbals movement. Further, the head slider  103  is mounted by means of adhesives to the surface side (corresponding to this side of paper surface) of the flexure tang  101 . 
     A support region  220  on the extreme end side is a part of the metallic layer  111 , which is spot-welded to the load beam  75   a  at the welding spot  112   a . From the edge near the welding spot  112   a , a pair of web-like main arms  204  extend to the support end side in symmetry with the center line joining the welding spots  112   a  and  112   b . The main arms  204  extend to the support end side surrounding the periphery of the flexure tang  101 , and become integrated with sub-arms  206  at a pair of positions  225  to form a pair of support arms  208 , supporting a leading edge  223  of the flexure tang  101 . All of the main arm  204 , the sub-arm  206  and the support arm  208  are a part of the metallic layer  111 . 
     The leading edge  223  termed herein is an end of the flexure tang on the side opposite to the side where the head is positioned when the head/slider  103  is mounted. An end on the side opposite to the leading edge of the flexure tang  101  is called a trailing edge. In the present disclosure, the terms of the leading edge and the trailing edge are to be used also with respect to the head slider  103  mounted on the flexure tang. 
     The flexure assembly  100  according to the present embodiment is applied to the magnetic disk drive of progressive rotation. In  FIG. 2 , the magnetic disk  66  rotates in the direction shown by arrow A from the support end side toward the extreme end side with respect to the flexure tang  101 . A viscous air current generated in the surface of the magnetic disk flows so that it moves into a region between the air bearing surface and the disk surface from the leading edge side of the head/sliver  103  and flows out of the trailing edge to give the head/slider  103  a floating force. 
     A support region  222  which is a part of the metallic layer  111  is spot-welded to the load beam  75   a  at the welding spot  112   b . A pair of sub-arms  206  extend symmetrically toward the extreme end side from the neighborhood of the welding spot  112   b . A plurality of polyimide isle-like regions  224  which are a part of the dielectric layer  113  are adhered to the flexure tang  101 . The isle-like regions  224  are provided to control an attitude of the slider when the head/slider  103  is adhered onto the flexure tang  101  by means of adhesives, and are laminated on the metallic layer  101  in the adhesion step of the dielectric layer  113  or the cover layer  117  shown in  FIG. 5(C) . Further, a pair of wiring traces  105  extend in parallel with the center line from the support region  222  on the support end side to the trailing edge side of the flexure tang  101 . The wiring traces  105  are adhered to the metallic layer  111  in the support region  222 , but extend to the support arm  208  near the flexure tang  101  without being adhered to other regions of the metallic layer  111  after having been separated from the support region  222 . 
     In the pair of wiring traces  105 , the conductor layer is divided into two and four lead wires in total are included. On the trailing edge side of the flexure tang  101 , there is formed a platform  214  for locating the end of the lead wire to the slider pad when the lead wire is connected to the slider pad provided on the side of the trailing edge side of the head/slider  103 . The platform  214  is a part of the metallic layer  111  is inclined in the direction mounting the slider  103  at 10 to 20 degrees with respect to the plane including the flexure tang  101  together with the dielectric layer  113  and the conductor layer  115 . 
       FIG. 7  is a side view for explaining the embodiment of the connection structure of the head/slider and the lead wire. A lead wire  230  is an element constituting the wiring trace  105  and is also a part of the conductor layer  115 . The connection structure of  FIG. 7  shows a part of X-X section in the state that the head/slider  103  is mounted on the flexure tang  101  of  FIG. 6 . The flexure tang  101  locks a bottom  135  of the slider  103  through a polyimide isle-like region  224 . A head  102  is formed at a corner formed by a side  131  on the trailing edge side of the head/slider  103  and an air bearing surface  133 . The head  102  is provided with a function of recording and reproducing or one of them. 
     The side  131  of the head/slider is provided with a slider pad  104  connected to the head  102 . The slider pads  104  are formed in line with the side  131  of the slider adjusting to the number of lead wires  230 . The slider pad  104  is formed closer to the air bearing surface  133  from the bottom  135  of the head/slider to prevent the slider pad  104  from short-circuiting with the body of the slider  103  due to the solder ball connection. The metallic layer  111  is bent on the slider pad  104  side in the vicinity of a position crossing the plane including the side  131  of the head/slider, and the platform  214  which is a part of the metallic layer  111 , the dielectric layer  113  adhered thereon, and the lead wire  230  adhered on the dielectric layer  113  are integrally inclined. The bent position is not limited to that of the present embodiment, but it may be bent at any position as long as a connection distance  237  can be formed as will be described later. Further, the bent structure can be formed by press working. An opening  227  is provided between the platform  214  and the flexure tang  101  in order to secure a dimensional tolerance of a mutual positional relation between the head/slider  103  and the lead wire  230 . 
     The dielectric layer  113  located under the lead wire  230  extends through the opening  227  so as to come closer to the slider pad  104  than the end  215  of the platform  214 . The lead wire  230  extends through the opening  227  so as to come closer to the slider pad  104  than the end  114  of the dielectric layer  113 . The dielectric layer  113  is extended from the end  215  of the platform to prevent short-circuiting between the lead wire  230  and the platform  214  because of the solder ball connection. Further, the lead wire  230  is extended from the end  114  of the dielectric layer  113  to prevent the dielectric layer  113  from burning when a laser beam for re-flowing the solder ball  233  is irradiated. 
     At the extreme end of the lead wire  230  is formed a lead pad  235  having a known solder ball holding structure as shown in Japanese Patent Laid-Open No. 2003-123217. The lead pad  235  means a position of the solder ball connection provided in the lead wire irrespective of the shape thereof. The head/slider  103  is fixed to the flexure tang  101  so that the side  131  is positioned close to the opening  227  from the trailing edge  231  of the flexure tang  101  to prevent the flexure tang  101  from short-circuiting with the slider pad  104  or the lead pad  235  at the time of re-flowing of the solder ball  233 . The solder ball  233  is temporarily fixed between the lead pad  235  and the slider pad  104  to re-flow by a laser beam whereby both the pads can be connected. The flexure assembly  100  is constituted so that a crossing angle between the plane including the slider pad  104  and the plane including the lead wire  230  is less than 90 degrees, enabling shortening the connection distance  237  as compared with the connection distance  23  described in  FIG. 1 , and capable of enhancing the quality and yield of the solder ball connection. The crossing angle is preferably in the range of about 70 to 80 degrees, and the lower limit of the crossing angle is determined according to the size of the solder ball  233  to be used. 
       FIG. 8  is a side view for explaining a further embodiment of the connection structure of the head/slider and the lead wire. In the connection structure of  FIG. 8(A) , only a lead wire  230  is separated from a dielectric layer  131  in the vicinity of a position crossing the plane including a side  131  of the head/slider and bent on the slider pad  104  side to form a connection distance  237 . Such a structure as described can be formed by press working in either an additive type wiring integral flexure assembly or a subtractive type wiring integral flexure assembly. 
     In the connection structure of  FIG. 8(B) , a metallic layer  111 , a dielectric layer  113 , and a conductor layer  115  are displaced upward in the figure in the vicinity of a position crossing the plane including the side  131  of the head/slider to form a connection distance  239 . In this structure, the plane including the lead wire  230  crosses with the slider pad  104 , and the connection distance  239  is shorter than the connection distance  23  shown in  FIG. 1 . The amount of displacement is set so that the plane including the lead wire  230  is to be the upper side from the lower side  106  of the slider pad  104 . To provide the structure that the plane including the lead wire  230  is to be the upper side from the lower side  106  of the slider pad  104 , the dielectric layer  113  may be laminated thickly on the metallic layer  111 , or the conductor layer  115  may be laminated thereon. 
       FIG. 9  is a side view for explaining another embodiment of the connection structure of the head/slider and the lead wire. In the connection structure of  FIG. 9 , the plane including the extreme end portion of a lead wire  230  and a slider pad  104  cross at a crossing angle over 90 degrees to form a connection distance  241 . The connection distance  241  is shorter than the connection distance  23  shown in  FIG. 1 . In  FIG. 9 , the lead wire  230  is separated from a dielectric layer  113  and bent upward, but the lead wire  230  and the dielectric layer  113  may be integrally bent. The dielectric layer  113  extends toward the slider pad  104  side beyond an end  215  of a platform  214 , and the lead wire  230  extends toward the slider pad  104  side beyond an end  114  of a dielectric layer. The crossing angle is varied according to a diameter of a solder ball, a connection distance, a head/slider structure, workability of fixing the solder ball, but in the present embodiment, the angle is set to the range of about 100 to 120 degrees. 
     It is to be understood that the above description is intended to be illustrative and not restrictive. Many embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined not with reference to the above description, but instead should be determined with reference to the appended claims alone with their full scope of equivalents.

Technology Classification (CPC): 7