Abstract:
A low manufacturing cost electrical connector for a disk drive suspension comprises lower cost, metal layer-free first flexible conductive laminate segment to connect to signal circuitry, a more expensive metal layer containing flexible conductive laminate second segment to connect to a slider, and a lower cost, easily variously shaped jumper segment supported on the actuator arm and coupled between said first and second segments to connect the slider to the signal circuitry in a manufacturing cost efficient way.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation in part of my copending application Ser. No. 09/304242 filed May 3, 1999, which is in turn a continuation in part of application Ser. No. 08/897,660 filed Jul. 21, 1997, now U.S. Pat. No. 5,901,016 issued May 4, 1999 which claims benefit to provisional application 06/162422 filed Oct. 28, 1999. 
     Statement Regarding Federally Sponsored Research or Development 
     Not applicable. 
     Reference to a Microfiche Appendix 
     Not applicable. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention has to do with disk drive suspensions, and more particularly with improvements in the design and structure of disk drive suspension electrical connectors that are used to carry current between a load beam-supported slider and suspension-associated signal circuitry. In a specific aspect, the invention provides a disk drive suspension in which the advantages of metal layer-free flexible conductive laminate segments, including lower cost and easier fabrication in various configurations to meet suspension design needs, are maximally obtained while retaining the benefits of a metal layer containing flexible conductive laminate segment from the load beam rigid portion forward. 
     2. Related Art 
     Signal circuitry has been electrically connected to the slider, including the recording head carried by the slider, by various types of electrical connectors including wire bundles and flexible circuitry exclusively or in combination with varying effectiveness and cost efficiencies. There is a considerable cost disparity between the available conductive laminates, the metal layer type conductive laminates being more expensive than the laminates of only trace conductors and an insulative film. Different suspension designs will require that the connector extending between the signal circuitry and the slider be configured differently, and take on unusual shapes in many instances. Configuring these shapes in the conductive laminate connector will often require much waste of material as the needed contours will not always nest or otherwise fall into an economical cutting pattern. In this case the added material costs of the metal layer laminate can be prohibitive. It is, however, often necessary to have the greater stiffness properties of the metal layer containing laminate at the slider or distal end of the suspension. 
     SUMMARY OF THE INVENTION 
     It is an object, therefore, of the invention to provide a disk drive suspension having electrical connectors that provide substantially the benefits of a flexible conductive circuit connection at lower cost and with easier fabrication. It is a further object to provide a hybrid of electrical connectors that avoid incurring the higher cost of the metal layer laminate over much of the length of the conductor and offer increased design freedom in the bulk of the conductor without unneeded added expense. A still further object is realized is to provide a suspension having the needed properties of the metal layer conductive laminate at the distal end where the slider is located, but not much beyond that end. Only lower cost, simple conductive trace and insulative layer laminate is used where the conductor must be specially configured with possible excessive waste of material. Other objects include retaining the manufacturing advantages of flexible conductive circuit, including ready automation of slider-to-flexure assembly and substantially bias-free attachment to the slider. 
     These and other objects of the invention to become apparent hereinafter are realized in a disk drive suspension comprising a load beam adapted to mount to an actuator arm of an actuator, the load beam having a distal rigid portion, and supported by the load beam a flexure for carrying a slider, an electrical connector running substantially the length of the actuator arm and the load beam to the slider, the connector comprising an electrically integrated hybrid of different segments including a first flexible conductive laminate segment free of a metal support layer and supported by the actuator and connected to signal circuitry, a second flexible conductive laminate segment including a metal support layer that is supported by the load beam and connected to the slider, and a third flexible conductive laminate jumper segment that is supported by the actuator arm and connected between the first and second segments, the segments being arranged sequentially and in such manner that the slider head is electrically coupled to the signal circuitry by the first flexible conductive laminate segment at the proximal end of the load beam, by the second flexible conductor laminate segment at the load beam distal rigid portion, and by the jumper segment between the first and second segments. 
     In this and like embodiments, typically, the first, second and jumper flexible conductive laminate segments each comprise at least one pair of conductive leads laminated with plastic film, the second segment further comprising a stainless steel layer laminated with the plastic film, and the second flexible conductive laminate segment is electrically connected to the slider substantially in slider movement bias free relation. 
     In a further embodiment, the invention provides a disk drive suspension comprising a load beam adapted to mount to an actuator arm extending from an actuator, the load beam having a distal rigid portion, and supported by the load beam a flexure carrying a slider, an electrical connector comprising an electrically integrated hybrid of different segments including a first flexible conductive laminate segment supported by the actuator and connected to signal circuitry, a second flexible conductive laminate segment including a metal support layer that is supported by the load beam and connected to the slider, and a third flexible conductive laminate jumper segment connected between the first and second segments and supported by the actuator arm along a major portion of the actuator arm length, the first segment and the jumper segment each comprising a two-component structure of copper conductors and plastic dielectric, and the second segment comprising copper conductors, plastic dielectric, and a stainless steel support laminated to the plastic dielectric, the conductors being joined at the proximate and distal ends of the jumper segment to define an continuous electrical path for carrying current from the slider head to signal circuitry beyond the actuator arm. 
     In this and like embodiments, typically, the first and second flexible conductive laminate segments are each free of junctions, the second and third flexible conductive laminates are respectively on opposite sides of said load beam, said load beam being apertured for interconnection of said second and third segments, or, the second and third flexible conductive laminates are each on the same side of said load beam, and the second flexible conductive laminate segment is electrically connected to the slider substantially in slider movement bias free relation. 
     In a further embodiment, the invention provides in combination: an actuator arm, a load beam and a slider, and the first, second and jumper flexible conductive laminate segments as above described, the segments being electrically coupled into a single electrical connector and arranged to conduct current from the slider to signal circuitry. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The invention will be further described in conjunction with the attached drawings in which: 
     FIG. 1 is a side elevation view, partly schematic, of a head stack assembly of suspensions according to the invention; 
     FIG. 2 is an oblique view of the invention suspension slider side up, the flexible conductive laminate segment being separated for clarity of illustration; 
     FIG. 3 is an oblique view of the invention suspension slider side down; 
     FIG. 4 is a view taken on line  4 — 4  in FIG. 2; and, 
     FIG. 5 is a view taken on line  5 — 5  in FIG.  3 . 
     FIG. 6 is a view like FIG. 1 of an alternative embodiment; and, 
     FIG. 7 is a view like FIG. 3 of the alternative embodiment. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention suspension utilizes a novel electrical connector in which the major portion of electrical connector, that portion that needs to be contoured the most to fit individual suspension requirements, comprises a jumper segment. The jumper segment is preferentially used where shaping of the connector dictates some waste of material. The jumper segment, being only a laminate of trace conductors and an insulative film is lower in cost that a metal layer containing conductive laminate. The jumper segment serves to connect first and second segments attached respectively to the device electronics at the proximate end of the suspension and the slider at the distal end of the suspension. The advantages of the invention include the possible reduction is material cost since the flexible circuit without a metal layer is relatively inexpensive in comparison with the metal layer-including laminate used here in relatively small amounts, just along the rigid portion of the load beam, and an absence of conductor bias at the slider/air bearing through the use of the laminate as opposed to more rigid materials such as wire. 
     In addition, the invention offers advantages in manufacturing. The proximate first segment is readily handled; the distal second segment of the flexible circuit and flexure when formed as a strip also can be handled with known manufacturing procedures, including placement and welding, and automation is feasible. The third or jumper segment is also readily handled, and there are relatively fewer junctions to be made and quality controlled. The product offers substantially the electrical performance of a wire bundle system. 
     With reference now to the drawing in detail, in FIGS.  1 - 5  a first embodiment of the invention disk drive suspension  10  comprises a load beam  12  and a flexure  14  mounted as shown in a stack of like suspensions supported by arms  16  of actuator  25 . Load beam  12  is generally planar and locally flanged to have side rails  18  in its rigid distal portion  20 . Load beam base portion  22  attaches to a mounting plate  24  that in turn mounts the load beam  12  to the actuator  25  via arm  16 . Signal circuitry element  26  is located at the proximate end  28  of the load beam  12  for the purpose of sensing and transmitting signal exchanges through electrical connector  66  with the slider  32  carried on flexure  14  attached to the load beam distal end  36 . Slider  32  defines an air bearing relative to the disk drive disk  34  and carries the electrical and magnetic portions of the head. 
     The load beam  12 , flexure  14 , slider  32  and signal circuitry element  26  shown are typical of suitable structures for their respective functions, with no particular form or design of load beam, flexure, slider or signal circuitry being critical to this invention. 
     The invention is concerned particularly with improvements in the design and form of the electrical connector  66  between the signal circuitry  26  and the slider  32 . The freedom of movement of tongue  38  of the flexure  14 , and rotation of the slider  32  in various axes, is critical to the optimum functioning of the suspension  10 . It is nonetheless required to attach electrical connectors to the flexure and fine leads to the slider  32 , without unduly affecting the movement freedom of these elements. In the present device, the connector  66  comprises an integrated hybrid of different segments namely first segment  40 , second segment  42  and a third or jumper segment  41  interposed between the first and second segments between connections  58  (to the first segment, and  68  to the second segment. Electrical connector first segment  40  and third or jumper segment  41  are each comprised of a flexible conductive laminate typically comprising conductive traces  62 , an insulative film  63  on which the traces are formed and a covering insulated film  65  as needed. First segment  40  is supported by the actuator arm  16  and is electrically coupled to the signal circuitry  26 . 
     The second segment  42  comprises flexible conductive laminate like first segment  40 , but also has a stainless steel layer  43 , FIG.  4 . Electrical connector second segment  42  is supported by the load beam rigid portion  20  and is electrically coupled to the slider  32 . Second connector segment  42  thus comprises metal support layer  43 , conductive traces  62 , and plastic insulative film  65 ; it can function as the flexure  14  and its leads used to electrically couple to the slider  32 . The flexible conductive laminate  42  segment is arranged to add no particular bias to flexure  32  movement. The use of flexible conductive laminate  42  as or with the flexure  14  enables automated attachment of the leads  44 ,  46  to the slider  32  as noted previously and is advantageous in the manufacturing process. 
     The third segment  41  as mentioned comprises flexible conductive laminate of traces  62  and film  63  like that of first segment  40 , for lower cost, over the major portion of the electrical connector  66  for purposes explained above, particularly in allowing great freedom of routing the connector with various shapes being economically feasible. Third segment  41  serves to connect or jump between the first and second segments  40 ,  42  and is readily replaceable should the need arise by simply disconnecting at the junctions  58 ,  68 . Thus, should damage occur to the jumper segment, it can be replaced without having to replace the entire head gimbal assembly or head stack assembly that might otherwise be required with a single electrical connector. 
     In addition to the configuration advantages noted above that use of a jumper segment  41  provides, there are benefits in manufacturing including absence of problematic long flex-wire leads on the jumper segment since this segment does not go to the device electronics. Also, the nature of the jumper segment can be varied to vary the electrical properties of the connector overall. 
     In the embodiment of FIGS.  1 - 5 , the connector jumper segment  41  comprised of metal layer-free conductive laminate does not lie on the same side of the load beam  12  as the slider  32 . Accordingly, the load beam is apertured at  54  just beyond the proximal end  56  of the load beam rigid portion  20 . The leads  44 ,  46  from the flexible conductive laminate second segment  42  are gathered at the rigid portion proximal end  56  and are there accessible through aperture  54  of the load beam  12  for connection to the distal ends of leads  48 ,  50  of third flexible conductive laminate  41 . The connector first flexible conductive laminate segment  40  extends to the junction  58  where it is joined to the third segment  41 . Third segment  41  then extends along the arm  16  and the load beam  12  length (to and through the aperture  54  as needed) for connection to the conductive leads  44 ,  46  of the second segment  42  flexible conductive laminate to form the complete electrical connector  66  running the length of the load beam and electrically interconnecting slider  32  and signal circuitry element  26 . 
     With reference to FIGS. 6 and 7, an alternate embodiment in which like parts have like numbers plus  100 , the connector jumper segment  141  comprised of metal layer-free conductive laminate lies on the same side of the load beam  112  as the slider  132 , that is below the load beam in the Figure, as shown by the segment being in dashed lines when below the load beam. Thus, while the load beam  112  is still shown apertured at  154  just beyond the proximal end  156  of the load beam rigid portion  120 , such aperture is not necessary as the segment  141  is on the same side as the second segment  142  and its slider  132 . The leads  144 ,  146  from the flexible conductive laminate second segment  142  are gathered at the rigid portion proximal end  156  for connection to the distal ends of leads  148 ,  150  of third flexible conductive laminate  141 . The connector first flexible conductive laminate segment  140  extends to the junction  158  where it is joined to the third segment  141 . Third segment  141  then extends along the arm  116  and the load beam  112  length for connection to the conductive leads  144 , 146  of the second segment  142  flexible conductive laminate to form the complete electrical connector  166  running the length of the load beam and electrically interconnecting slider  132  and signal circuitry element  126 . 
     The invention thus provides a disk drive suspension having electrical connectors that provide substantially the benefits of a flexible conductive circuit connection at lower cost and with easier fabrication by using a hybrid of electrical connectors that avoid incurring the higher cost of the metal layer laminate over much of the length of the conductor and offer increased design freedom in the bulk of the conductor without unneeded added expense. A suspension is provided having the needed properties of the metal layer conductive laminate at the distal end where the slider is located, but not much beyond that end. Only lower cost, simple conductive trace and insulative layer laminate is used where the conductor must be specially configured with possible excessive waste of material while retaining the manufacturing advantages of flexible conductive circuit, including ready automation of slider-to-flexure assembly and substantially bias-free attachment to the slider. The foregoing objects of the invention are thus met.