Abstract:
A disk drive suspension and method has a limiter structure that limits movement of the tongue relative to a surrounding frame by extending the plastic film layer and optionally the metal layer components of a flexure-defining flexible circuit laminate beyond the flexure tongue distal end and attaching the terminal regions of the extended components to the surrounding frame laterally of the tongue. The flexure-defining laminate is attached to the suspension rigid portion proximally and optionally distally as well as laterally with the limiter structure. A lift tip can be used to enable lifting of the suspension and to stiffen the suspension in lieu of the distal attachment of the flexible circuit.

Description:
RELATED APPLICATIONS 
   This application is a continuation of application Ser. No. 10/010,997 filed Nov. 30, 2001, now U.S. Pat. No. 6,757,137 issued Jun. 29, 2004, which application claims the benefit of Provisional Application Ser. No. 60/326,509, filed Sep. 30, 2001. 

   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 relates to disk drive suspensions, and more particularly to disk drive suspensions of the wireless type that use a flexible circuit supported by a rigid portion of a load beam or stiffener. The invention provides bonding legs laterally of the flexure portion of the suspension that are continued extents of the insulative plastic film or laminates of that film and a base layer for purpose of limiting lateral and vertical shock and thus damage. The continued extents turn reversely from the tongue distal end to lie along the tongue edges spaced laterally of and supported beyond the tongue in tongue excursion limiting relation. Stiffness control is achieved as well as a limiter function. 
   2. Description of the Related Art 
   Disk drive suspensions previously known tend to be too stiff for small form factor applications, and limiters continue to need improvement in formability and effectiveness. 
   BRIEF SUMMARY OF THE INVENTION 
   It is an object of the invention therefore to provide an improved disk drive suspension. It is a further object to provide a disk drive suspension of the wireless type in which the flexible circuit comprising the trace conductors is used to define a flexure. A further object is to tether the flexure tongue laterally of the flexure tongue edges to limit undue tongue travel. Another object is to provide multiple points of attachment for the flexure and its tethers to effect flexure attachment while controlling stiffness to desired values. A further object is the provision of a front-end lifter and stiffener that reduces or eliminates gluing at the flexure trailing edge. Yet another object is the provision of a suspension using copper-based laminate, or other material-based laminates, as the flexible circuit in preference to stainless steel-based laminates. 
   These and other objects of the invention to appear hereinafter are realized in a disk drive suspension comprising a rigid portion defining a first dimple locus, a flexible circuit supported by the rigid portion, the flexible circuit comprising a plurality of trace conductors and an insulative plastic film, a flexure at the distal end of the rigid portion comprising a tongue and a tongue support, the tongue comprising a section of the insulative plastic film and defining a second dimple locus opposite the first dimple locus, the insulative plastic film having continued extents arranged to tether the tongue and limit tongue travel away from the rigid portion. 
   In a further embodiment, the invention provides a disk drive suspension comprising a rigid portion defining a dimple, a flexible circuit supported by the rigid portion, the flexible circuit comprising a plurality of trace conductors and an insulative plastic film, a flexure at the distal end of the rigid portion comprising a cantilevered tongue having left and right side edges and connected to a tongue support between the side edges, the tongue comprising a section of the insulative plastic film and defining a dimple locus opposite the dimple, the insulative plastic film being attached to the tongue support and connecting the tongue support and the tongue, the section having a continued extent beyond the tongue, the continued extent comprising a center continued extent leading away from the section and reversely extending left and right side extents spaced respectively from the tongue left and right side edges, the side extents having respective left and right terminal regions, the terminal regions being attached to the rigid portion left and right of the tongue, the side extents limiting tongue travel away from the rigid portion. 
   In the foregoing and like embodiments, typically, the flexible circuit is also attached to the rigid portion proximally of the flexure section, the flexible circuit is attached to the rigid portion distally of the flexure section, the flexible circuit is also attached to the rigid portion proximally of the flexure section, or a lift-stiffener may be used, the flexible circuit further including a copper metal layer opposite the traces across the film, the tongue is connected to the tongue support between the side edges, and the continued extent comprises a center continued extent leading away from the section, and the left and right side extents extend reversely relative to the center continued extent. 
   In a further embodiment, the invention provides a disk drive suspension comprising a rigid portion having an elongated body terminating distally in a flexure support frame and a dimple, a flexible circuit comprising a plurality of trace conductors and an insulative plastic film, a flexure supported by the support frame, the flexure comprising a flexure frame having a base and a tongue cantilever-supported by the frame base, the tongue having left and right side edges, the tongue comprising a section of the insulative plastic film and defining a dimple locus opposite the dimple, and left and right reversely turned continued film extents beyond the tongue attached to the support frame inward of the flexure frame to connect the tongue to the support frame in tongue travel limiting relation. 
   In this and like embodiments, typically, the flexible circuit is also attached to the rigid portion body proximally of the flexure section, the flexible circuit is attached to the rigid portion support frame distally of the flexure section, the flexible circuit is also attached to the rigid portion body proximally of the flexure section, the flexible circuit further including a copper metal layer opposite the traces across the film, the tongue is connected to the tongue support between the side edges, and there is a center continued extent leading away from the section, the left and right side extents extending reversely relative to the center continued extent. 
   In all embodiments, the invention can include a lifter structure formed at the distal end of the rigid portion, the lifter structure tending to stiffen the rigid portion, the lifter structure extending distally of the rigid portion, and the flexible circuit can be free of attachment to the rigid portion distally of the flexure section. 
   In certain embodiments, the rigid portion is deflected as needed to have its distal end substantially parallel with an opposing disk. 
   In certain embodiments, the flexure includes a frame having a distal part extending laterally of the rigid portion, the rigid portion being locally shaped opposite the frame distal part against wearing engagement of the rigid portion with the flexure frame. 
   The invention further provides a flexure for a disk drive suspension comprising for support by a rigid portion a flexible circuit laminate of a metal layer, a plurality of trace conductors and an insulative plastic film separating the metal layer from the traces, the laminate being arranged into a tongue and a tongue support, the tongue comprising the insulative plastic film and metal layer and defining a dimple locus, the insulative plastic film having continued extents beyond the tongue arranged to limit tongue travel away from the rigid portion. 
   In another embodiment, there is provided in accordance with the invention, a disk drive suspension comprising a rigid portion defining a first dimple locus, a flexible circuit supported by the rigid portion, the flexible circuit comprising a laminate of a copper-based metal layer, a plurality of trace conductors and an insulative plastic film separating the metal layer from the traces, a flexure at the distal end of the rigid portion comprising a tongue and a tongue support, the tongue comprising the insulative plastic film and metal layer and defining a second dimple locus opposite the first dimple locus, the insulative plastic film having continued extents arranged to limit tongue travel away from the rigid portion. 
   In yet another embodiment, the invention disk drive suspension comprises a rigid portion defining a first dimple locus, a flexible circuit supported by the rigid portion, the flexible circuit comprising a laminate of a metal layer, a plurality of trace conductors and an insulative plastic film separating the metal layer from the traces, a flexure at the distal end of the rigid portion comprising a tongue and a tongue support, the tongue comprising the insulative plastic film and metal layer and defining a second dimple locus opposite the first dimple locus, the insulative plastic film having continued extents arranged to limit tongue travel away from the rigid portion. 
   A further embodiment includes a disk drive suspension comprising a rigid portion defining a dimple, a flexible circuit supported by the rigid portion, the flexible circuit comprising a metal layer, a plurality of trace conductors and an insulative plastic film, a flexure at the distal end of the rigid portion comprising a cantilevered tongue having left and right side edges and connected to a tongue support between the side edges, the tongue comprising a section of the metal and insulative plastic film and defining a dimple locus opposite the dimple, the insulative plastic film being attached to the tongue support and connecting the tongue support and the tongue, the section having a continued extent beyond the tongue, the continued extent comprising a center continued extent leading away from the section and reversely extending left and right side extents spaced respectively from the tongue left and right side edges, the side extents having respective left and right terminal regions, the terminal regions being attached to the rigid portion left and right of the tongue, the side extents limiting tongue travel away from the rigid portion. 
   In these and like embodiments, typically, the flexible circuit is also attached to the rigid portion proximally and optionally distally of the flexure section, the metal layer is a copper metal layer opposite the traces across the film, the tongue is connected to the tongue support between the side edges, and the continued extent comprises a center continued extent leading away from the section, and the left and right side extents extend reversely relative to the center continued extent. 
   A further embodiment has a disk drive suspension comprising a rigid portion having an elongated body terminating distally in a flexure support frame and a dimple, a flexible circuit comprising a metal layer, plurality of trace conductors and an insulative plastic film therebetween, a flexure supported by the support frame, the flexure comprising a flexure frame having a base and a tongue cantilever-supported by the frame base, the tongue having left and right side edges, the tongue comprising a section of the insulative plastic film and defining a dimple locus opposite the dimple, and left and right reversely turned continued film extents beyond the tongue attached to the support frame inward of the flexure frame to connect the tongue to the support frame in tongue travel limiting relation. 
   In this and like embodiments, typically, the tongue is connected to the tongue support between the side edges, there is a center continued extent leading away from the section, and the left and right side extents extending reversely relative to the center continued extent. 
   As in certain of the previous embodiments, typically, there can be included a lifter structure formed at the distal end of the rigid portion, the lifter structure tending to stiffen the rigid portion, the lifter structure extends distally of the rigid portion, and the flexible circuit is free of attachment to the rigid portion distally of the flexure section, the rigid portion is deflected as needed to have its the distal end substantially parallel with an opposing disk, and the flexure includes a frame having a distal part extending laterally of the rigid portion, the rigid portion being locally shaped opposite the frame distal part against interference of the rigid portion with the flexure frame. 
   Further, typically, in certain embodiments, the flexure frame has a distal part extending laterally of the rigid portion support frame, the rigid portion being locally shaped opposite the frame distal part against interference of the rigid portion with the flexure frame. 
   In its method aspects the invention contemplates a method of limiting the movement of a flexure tongue relative to a surrounding frame, including maintaining a plastic film layer movable with the tongue, providing an extension of the plastic film beyond the distal perimeter of the tongue and connecting the plastic film extension to the surrounding frame laterally of the tongue and proximally of the tongue distal perimeter. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
     The invention will be further described in conjunction with the attached drawings in which: 
       FIG. 1  is a bottom plan view of the complete invention suspension; 
       FIG. 2A  is a top plan view of a part of the suspension; 
       FIG. 2B  is a bottom plan view of a part of the suspension; 
       FIG. 3A  is a further top plan view thereof; 
       FIG. 3B  is a bottom plane view thereof; 
       FIG. 3C  is a side elevation view thereof; 
       FIG. 4  is a view in vertical section of the distal portion of the suspension; 
       FIG. 5  is an exploded view of the suspension distal portion; and, 
       FIG. 6  is a view like  FIG. 3B  of an alternate form of the invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The invention uses added points of attachment laterally of the flexure to increase control over pitch and roll stiffness and have lower stiffness in very small suspensions such as femto form factor suspensions. The invention uses bonding legs from the flexure tongue area, generally formed from continued extents of the flexible circuit section in the tongue area, as anchors to adjust pitch and roll stiffness and also to act as a limiter structure for slider loading and unloading. Vertical and lateral shock damage to the suspension is prevented by the bonding leg anchors. Compared to conventional trace suspension assemblies, the present device does not require a stainless steel base layer. A flexible circuit is employed that uses no base layer, or preferably a copper metal layer or other metal or plastic base layer, an insulative film layer such as polyimide, and trace conductors such as copper traces. The copper base layer will typically be over-plated with gold or nickel/gold plating composition, or other material to limit environmental degradation. The thickness of a flexible circuit laminate base layer of copper metal will be about 0.005 to about 0.01 mm. A conventional stainless steel base layer, however, can be used as or in addition to the copper metal or other base layer where thickness and stiffness property requirements of the application are met. The new flexible circuit is bondable to the suspension rigid portion. Attachment by gluing, welding or laminating processes is suitable. 
   Stiffness control is maintained by placing glue laterally of the flexure on the terminal regions of the anchor legs formed by the flexure section continued extents, and at the trailing edge of the flexure which increases lateral stiffness remarkably. The invention provides good control over flexure stiffness properties, such as a pitch stiffness Kp of 0.79 uNM/deg, roll stiffness Kr of 0.71 uNM/deg and a very high lateral stiffness KI of 22.4 N/mm. 
   In an alternate form, flexure trailing edge gluing is omitted and a stiffener/lifter is added, giving a pitch stiffness Kp of 0.51 uNM/deg, a Kr of 0.70 uNM/deg and a lateral stiffness KI of 8.4 N/mm. 
   In the invention, pitch adjustment is not needed in some embodiments as the suspension rigid portion is formed with a desired angle that forces the flexure tongue to be parallel to the disk opposed in the installed condition of the suspension. A lifter can be readily incorporated into the design, increasing stiffness and optionally making unnecessary any trailing edge gluing of the flexure. 
   With reference now to the drawings in detail, in  FIGS. 1–5  disk drive suspension  10  is shown to comprise a rigid portion  12  integral with or separate from and connected to load beam base portion  14  and spring portion  16 . Rigid portion  12  defines a first dimple locus  18 . A dimple locus herein is a dimple per se, i.e. a rounded protuberance that projects from a surrounding surface such as the surface of the load beam rigid portion, and/or a dimple locus can be a surface that is the target of the projecting dimple that can typically be formed on the tongue. Thus the term dimple locus covers both the protuberant dimple as the locus and the target surface, be it flat or rounded, as the dimple locus. 
   Flexible circuit  22  extends from the device electronics (not shown) along the suspension  10  from base portion  14 , past spring portion  16  and to rigid portion  12  that supports the flexible circuit. 
   Flexible circuit  22  comprises a laminate  23  of a plurality of trace conductors  24  defining read/write circuits between the device electronics and slider  25  ( FIG. 2B ), an insulative plastic film  26 , and a copper metal (or other base material hereinafter described) base layer  28 . 
   In the embodiment of  FIG. 6 , the flexible circuit  221  comprises a laminate  231  of a plurality of trace conductors  241  defining read/write circuits and an insulative plastic film  261 . No base layer of copper, stainless steel or other material is present. The  FIG. 6  embodiment is otherwise like the  FIGS. 1–5  embodiment now to be described with like parts having like numerals plus a terminal  1 , e.g.  26  in  FIGS. 1–5  is  261  in  FIG. 6 . 
   In the embodiment of  FIGS. 1–5 , flexible circuit  22  defines a flexure  30  at the distal end  32  of the rigid portion  12 . Flexure  30  comprises a tongue  34  and a tongue support  36 . Tongue  34  comprises a generally rectangular section  38  of laminate  23  including the insulative plastic film  26  and copper metal base layer  28  ( 28  not present in tongue  341  in  FIG. 6 ). Tongue  34  defines a second dimple locus  42  opposite the first dimple locus  18 . 
   Insulative plastic film  26  (or  261 ) has left and right continued tethers or extents  44  ( 441 ),  46  ( 461 ) arranged to limit tongue  34  ( 341 ) travel away from the rigid portion  12  ( 121 ) for purposes to be described hereinafter. 
   With further reference to  FIGS. 1–5 , the suspension rigid portion  12  defines as the first dimple locus  18  a projecting dimple  48  that extends from the surface  52  of the rigid portion  12  toward the second dimple locus  42  which in this embodiment is a flat  54  that will permit the tongue  34  and its carried slider  25  to gimbal about the dimple. 
   Tongue  34  has left and right side edges  56 ,  58  respectively, and is cantilevered from its proximate end  62  that is connected to tongue support  36  at a location between the side edges. Insulative plastic film  26  and/or base metal layer  28  are attached to the tongue support  36  and connect the tongue support and the tongue  34 . Tongue  34  comprises the section  38  that has an insulative film  26 —constituted continued extent  64  beyond the distal end  66  of the tongue. Continued extent  64  comprises a center continued extent  68  leading away from the section  28  and reversely extending (as shown) left and right side extents  44 ,  46  spaced respectively from the tongue left and right side edges  56 ,  58 . Side extents  44 ,  46  have respective left and right terminal regions  72 ,  74 , attached respectively to the suspension  10  beyond the tongue  34 , e.g. to the rigid portion  12  at locations  35 ,  37  to the left and right of the tongue. These side extents  44 ,  46  are shaped and sized and are sufficiently inextensible under the load imposed by the tongue  34  and the slider  25  during suspension operation to limit tongue travel away from the rigid portion  12  to a degree determined by the design but which typically prevents the slider from touching the disk (not shown). 
   In further detail, the flexible circuit  22  is also attached to the rigid portion  12  proximally of the flexure section at  76  and optionally distally thereof at  78  along the elongated body  79  of the rigid portion. 
   In  FIG. 6 , the flexible circuit  221  is not glued or otherwise attached to the rigid portion other than at the flexure side extent terminals  721 ,  741  reducing stiffness attributable to the attachment. In  FIG. 6  a front-end lifter  82  is provided extending from the rigid portion  121 . Lifter  82  and its support  84  at the distal end  86  of the rigid portion  121  tend to stiffen the flexure there but with less stiffening than with gluing of the flexure  30  to the rigid portion as shown in  FIGS. 1–5 . 
   With particular reference to  FIGS. 3A ,  3 B and  3 C, the rigid portion  12  is deflected along a transverse line  92  proximally of the flexure  30  to counteract the sag bend  94  condition shown, as needed to have the suspension distal end  96  and the flexure carried slider  25  substantially parallel with an opposing disk. 
   In further reference to  FIGS. 3A ,  3 B, and  3 C the flexure  30  has a generally rectangular frame  98  having a distal cross member  102  defining the tongue support  36  and lateral members  104 ,  105  extending in spaced relation laterally of the rigid portion  12 . Cross-member  102  defines the distal end of flexure frame  98  to extend across the rigid portion  12 . Rigid portion  12  being locally shaped at  106  opposite the frame distal cross-member  102  against wearing engagement of the rigid portion with the flexure frame  28 . 
   With particular reference to  FIGS. 4 and 5 , the invention flexure  30  for a disk drive suspension preferably comprises for support by a rigid portion  12  a flexible circuit laminate  23  comprising a base metal layer  28 , such as copper metal (metal containing a major weight amount of copper), or other suitable base material including stainless steel, the copper base layer having a thickness of between about 0.005 and 0.01 mm., a plurality of trace conductors  24  formed from a trace layer  112  having a thickness of about 0.018 mm., an insulative plastic film layer  26 , such as a polyimide film having a thickness of about 0.025 mm., the laminate being supported by a stiffener or load beam rigid portion  12  suitably of stainless steel and having a thickness of about 0.0760 to 0.1020 mm., and in some cases having a cover layer  114  of plastic having a thickness about 0.005 to about 0.008 mm. 
   Insulative film  26  separates the metal base layer  28  from the traces  24 , the laminate  23  being arranged into the tongue  34  and the tongue support  36 , the tongue comprising the insulative plastic film  26  and base metal layer  28  and defining a second dimple locus  42 , the insulative plastic film having continued extents  44 ,  46  beyond the tongue arranged to limit tongue travel away from the rigid portion  12 . 
   In its method aspects, the invention contemplates a method of limiting the movement of a flexure tongue  34  relative to a surrounding frame  98 , including maintaining a plastic film layer  26  movable with the tongue, providing an extension  64  of the plastic film beyond the distal perimeter  66  of the tongue and connecting the plastic film extension to the surrounding frame laterally of the tongue and proximally of the tongue distal perimeter. 
   The invention thus provides an improved disk drive suspension of the wireless type in which the flexible circuit comprising the trace conductors is used to define a flexure in which the flexure tongue is tethered laterally of the flexure tongue edges to limit undue tongue travel. The invention further provides multiple points of attachment for the flexure and its tethers to effect flexure attachment while controlling stiffness to desired values, and a front-end lifter and stiffener that reduces or eliminates gluing at the flexure trailing edge. The invention provides a suspension using copper-based laminate, or other material-based laminates, as the flexible circuit in preference to stainless steel-based laminates. 
   The foregoing objects are thus met.