Abstract:
A wireless disk drive suspension and method of manufacture in which curvilinear deflections of the plastic film and conductive traces relative to the flexure metal layer provide for containment of the strains accompanying pitch and roll adjustment of the flexure and allow adjustment free of adjusting difficulties and spring back compromise of the adjustment. The curvilinear deflection of the laminate toward the flexure central longitudinal axis and an accompanying bringing in of the flexure frame struts provides a less wide flexure that can more closely approach a disk drive hub for greater capacity in a disk drive.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of U.S. Provisional Application Ser. No. 60/681,588, filed May 16, 2005 

   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 wireless disk drive suspensions, and more particularly to improvements in wireless suspension enabling more precise making and retaining of pitch and roll adjustments in the flexure portions of the suspensions. 
   2. Description of the Related Art 
   Pitch (Pitch Static Attitude, PSA) and roll (Roll Static attitude, RSA) adjustment of suspensions is a final step in manufacture intended to place the flexure carried slider in its designed disposition. In wireless suspensions this adjustment remains problematical since the stainless steel layer and the polyimide and trace layers have differing responses to the adjustment. In wireless suspensions incorporating flexures, known variously as CIS, TSA and FSA, a typical thickness range for the stainless steel layer is 0.02 to 0.025 mm., the polyimide thickness is about 0.006 to about 0.025 mm., and the copper traces are about 0.008 to about 0.018 mm. Typically, the pitch/roll adjustment of the flexure puts the traces under compression or tension or both sequentially depending on the adjustment being made. Often the adjustment is repeated in a trial and error process, further stressing the traces and putting strain energy into the traces that will springback or return to other than their adjusted state after the adjustment process, compromising the PSA/RSA changes made. 
   BRIEF SUMMARY OF THE INVENTION 
   It is an object of the invention to provide an improved suspension, and particularly an improved suspension flexure. It is another object to provide a suspension and flexure therefor where strain energy build-up in the flexure during PSA/RSA adjustments and consequent difficult adjustments and post-adjustment, springback losses of precision are minimized. It is a further object to provide an improved wireless flexure design. Yet another object is to provide a relief from the straight path, minimum material approach of the prior art to introduce curves into the flexure trace and plastic film laminate that offset or absorb the strains imposed by pitch and roll adjustments, making the fact of different materials in the flexure less significant. A further object is to deflect the laminate locally to provide curvilinear shapes for stress take-up. Another object is to deflect the laminate toward the flexure central longitudinal axis and bring the flexure struts in a like amount to narrow the width of the flexure, enabling closer approach of the suspension to the disk drive hub for increased disk drive capacity. 
   These and other objects of the invention to become apparent hereinafter are realized in a wireless disk drive suspension comprising a beam portion and a flexure frame having a given length between transverse members and subject to tension and compression forces during pitch and roll adjustment of the flexure, the frame comprising a metal layer portion and a laminate portion of trace conductors and an insulative plastic film supported by the metal layer, the flexure having a tongue for supporting a slider, the metal layer portion defining longitudinal struts, the laminate portion of the flexure having a greater length than the flexure frame given length to reversely deflect along its greater length against accumulation of tension or compression forces during the pitch and roll adjustment and adjustment compromising springback. 
   In this and like embodiments, typically, the metal layer comprises stainless steel, the insulative plastic comprises polyimide, the trace conductors comprise copper, the laminate portion reverse deflection defines a curvilinear lateral displacement of the laminate portion, the flexure frame has a central longitudinal axis, the curvilinear lateral displacement of the laminate portion being away from the frame central longitudinal axis, or the curvilinear lateral displacement of the laminate portion being toward the frame central longitudinal axis, or the curvilinear lateral displacement of the laminate is both toward and away from the frame central longitudinal axis, the curvilinear lateral displacement of the laminate is serpentine and has an intermediate section displaced toward the frame central longitudinal axis, and/or the flexure frame metal layer portion is displaced oppositely from the laminate portion intermediate section displacement relative to the frame central longitudinal axis. 
   In a further embodiment, the invention provides a wireless disk drive suspension comprising a beam portion and a flexure frame comprising a metal layer portion and a laminate portion of trace conductors and an insulative plastic film supported by the metal layer, the flexure having a tongue for supporting a slider, the metal layer portion defining left and right longitudinal struts between the transverse members, the laminate portion of the flexure having left and right extents reversely deflected to have their respective intermediate sections displaced inward toward the central longitudinal axis of the frame, the metal layer portion struts having middle regions lying along the laminate portion displaced intermediate sections to reduce the width of the flexure by approximately the displacement of the intermediate sections for relatively closer positioning of the flexure to a disk drive hub. As in the previous embodiment the flexure preferably comprises stainless steel, polyimide and copper, and the laminate portion reverse deflection defines a curvilinear lateral displacement of the laminate portion. 
   The invention methods include a method of manufacturing a wireless disk drive suspension comprising a beam portion and a flexure frame having a central longitudinal axis and comprising a metal layer portion and a laminate portion of trace conductors and an insulative plastic film supported by the metal layer, including reversely deflecting the laminate portion along its metal layer supported length, pitch and roll adjusting the flexure, and blocking accumulation of tension or compression forces in the laminate portion with the reverse deflection in the laminate portion during the pitch and roll adjustment and adjustment against adjustment compromising springback thereof. 
   In this and like embodiments, typically, the method includes selecting stainless steel as the metal layer, polyimide as the insulative plastic, and copper as the trace conductors, defining a curvilinear lateral displacement of the laminate portion with the reverse deflection thereof, displacing the curvilinear lateral displacement of the laminate portion away from the frame central longitudinal axis or toward the frame central longitudinal axis, displacing the flexure frame metal layer portion oppositely from the laminate portion displacement relative to the frame central longitudinal axis, displacing the curvilinear lateral displacement of the laminate both toward and away from the frame central longitudinal axis, serpentine-displacing the curvilinear lateral displacement of the laminate, and displacing an intermediate section thereof toward the frame central longitudinal axis, and/or displacing the flexure frame metal layer portion oppositely from the laminate portion intermediate section displacement relative to the frame central longitudinal axis. 
   In a further embodiment, the invention provides a method of manufacturing a wireless disk drive suspension comprising a beam portion and a flexure frame having a central longitudinal axis and longitudinally spaced transverse members comprising a metal layer portion and a laminate portion of trace conductors and an insulative plastic film supported by the metal layer, defining middle regions in left and right longitudinal struts between the transverse members, defining in the laminate portion left and right extents reversely deflected to have their respective intermediate sections displaced inward toward the central longitudinal axis of the frame, displacing the metal layer portion struts middle regions to lie along the laminate portion displaced intermediate sections, whereby the width of the flexure is reduced by approximately the displacement of the intermediate sections for relatively closer positioning of the flexure to a disk drive hub. 

   
     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 plan view of the invention suspension and flexure; 
       FIG. 2  is a plan view of another embodiment thereof; 
       FIG. 3  is a plan view of a further embodiment thereon; and 
       FIG. 4  is a cross section view of the suspension and flexure of  FIG. 1  taken along line  4 - 4 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   With reference now to the drawings in detail, in  FIGS. 1 and 2  a wireless disk drive suspension  10  comprises a beam portion  12  and a flexure  13  comprising a frame  14  having a given length  16  between longitudinally spaced transverse members  18 ,  22 . Flexure frame  14  is subject to tension and compression forces during pitch and roll adjustment of the flexure  13 . Flexure frame  14  comprises a metal layer portion  24  and a laminate portion  26  of trace conductors  28  and an insulative plastic film  32  supported by the metal layer. Flexure frame  14  has a tongue  34  supporting a slider  36 . Flexure metal layer portion  24  defines longitudinal struts  38 ,  42 . Laminate portion  26  of the flexure frame  14  divides into left and right extents  44 ,  46 . Each laminate portion part  44 ,  46  has a greater length  48  than the flexure frame given length  16  and to fit within the given extent  16  is reversely deflected as shown at  52  along its greater length  48  against accumulation of tension or compression forces therein during the pitch and roll adjustment and adjustment compromising springback. 
   As noted, metal layer portion  24  can comprise stainless steel, the insulative plastic film  32  of laminate portion  26  comprises polyimide, and the trace conductors  28  comprise copper. 
   The laminate portion  26  reverse deflection  52  defines a curvilinear lateral displacement  54  of the laminate portion. Flexure frame  14  has a central longitudinal axis A-A. The curvilinear lateral displacement  54  of the laminate portion  26  can be away from the frame central longitudinal axis A-A, see  56  in  FIG. 1 , or toward the frame central longitudinal axis, see  58  in  FIG. 2 . Alternatively, again with reference to  FIG. 1 , the curvilinear lateral displacement of the laminate is both toward  62  and away  56  from the frame central longitudinal axis A-A, such that the curvilinear lateral displacement  56 ,  62  of the laminate portion  26  is serpentine  64 . When serpentine, laminate portion  26  has an intermediate section  66  displaced toward the frame central longitudinal axis A-A. And, the flexure frame metal layer portion  24  can be displaced oppositely, (i.e. outwardly from axis A-A), from the laminate portion intermediate section  66  displacement relative to the frame central longitudinal axis. The inward deflection of intermediate sections  66  in  FIG. 2 , provides good access to struts  38 ,  42  which is useful for RSA and PSA adjustments. 
   As shown in  FIG. 2 , the laminate portion in the area longitudinally between the longitudinal struts, intermediate section  66 , is displaced inward toward axis A-A from the laminate portion proximate to and distal to the area longitudinally between the struts. 
   In a further embodiment, shown in  FIG. 3 , a wireless disk drive suspension  10  comprises a beam portion  12  and a flexure  13  comprising a frame  14 . Flexure frame  14  comprises a metal layer portion  24  and a laminate portion  26  of trace conductors  28  and an insulative plastic film  32  supported by the metal layer. Flexure frame  14  has a tongue  34  for supporting a slider  36 . Metal layer portion  24  defines left and right longitudinal struts  38 ,  42  between transverse members  18 ,  22 . The laminate portion  26  of the flexure frame has left and right extents  44 ,  46  reversely deflected at  52  to have their respective intermediate sections  66  displaced inward toward the central longitudinal axis A-A of the frame  24 . Metal layer portion struts  38 ,  42  have middle regions  68  lying along the laminate portion displaced intermediate sections  66 , rather than spaced well outboard thereof as in  FIGS. 1 and 2 , to reduce the width  72  of the flexure frame  14  by approximately the displacement d of the intermediate sections  66  for relatively closer positioning of the flexure  13  to a disk drive hub (not shown). 
   Typical pitch, roll and stiffness values for the  FIGS. 1-3  embodiments are provided in the TABLE following. 
   
     
       
             
           
             
             
             
             
           
             
             
             
             
           
         
             
               TABLE 1 
             
           
           
             
                 
             
             
               Flexure Stiffness (CIS) 
             
           
        
         
             
                 
               Pitch Stiffness 
               Roll Stiffness 
               Lateral Stiffness 
             
             
                 
               (μNM/deg) 
               (μNM/deg) 
               (N/mm) 
             
             
                 
                 
             
           
        
         
             
               Case 1 (FIG. 1) 1   
               0.71 
               0.67 
               2.40 
             
             
               Case 2 (FIG. 2) 1   
               0.72 
               0.68 
               2.41 
             
             
               Case 3 (FIG. 3) 2   
               0.70 
               0.70 
               2.20 
             
             
                 
             
             
                 1 Stainless Steel: 25 μm; Polyimide: 6 μm: Copper Layer: 10 μm. 
             
             
                 2 Stainless Steel: 25 μm; Polyimide: 10 μm; Copper Layer: 10 μm. 
             
           
        
       
     
   
   The invention methods include a method of manufacturing a wireless disk drive suspension  10  comprising a beam portion  12  and a flexure  13  comprising a frame  14  having a central longitudinal axis A-A and comprising a metal layer portion  24  and a laminate portion  26  of trace conductors  28  and an insulative plastic film  32  supported by the metal layer portion  24 . The method includes reversely deflecting the laminate portion  26  along its metal layer  24  supported length, pitch and roll adjusting the flexure  13 , and blocking accumulation of tension or compression forces in the laminate portion with the reverse deflection  52  in the laminate portion during the pitch and roll adjustment against adjustment-compromising springback thereof. 
   The foregoing embodiment of the invention method further includes selecting stainless steel as the metal layer  24 , polyimide as the insulative plastic  32 , and copper as the trace conductors  28 . According to the method a curvilinear lateral displacement  54  of the laminate portion  26  is defined with the reverse deflection  52  thereof, displacing the curvilinear lateral displacement  56  of the laminate portion away from the frame central longitudinal axis A-A, or toward  58  the frame central longitudinal axis, displacing the flexure frame metal layer portion  24  oppositely from the laminate portion displacement relative to the frame central longitudinal axis, displacing the curvilinear lateral displacement of the laminate both toward and away  56 ,  62  from the frame central longitudinal axis, serpentine  64 -displacing the curvilinear lateral displacement  56 ,  62  of the laminate, and displacing an intermediate section  66  thereof toward the frame central longitudinal axis, and/or displacing the flexure frame metal layer portion oppositely from the laminate portion intermediate section displacement relative to the frame central longitudinal axis. 
   In a further invention embodiment a method of manufacturing a wireless disk drive suspension  10  comprising a beam portion  12  and a flexure  13  comprising a flexure frame  14  having a central longitudinal axis A-A and longitudinally spaced transverse members  18 ,  22  comprising a metal layer portion  24  and a laminate portion  26  of trace conductors  28  and an insulative plastic film  32  supported by the metal layer, includes defining middle regions  68  in left and right longitudinal struts  38 ,  42  between the transverse members, defining in the laminate portion left and right extents  44 ,  46  reversely deflected at  52  to have their respective intermediate sections  66  displaced inward toward the central longitudinal axis of the frame, displacing the metal layer portion strut middle regions to lie along the laminate portion displaced intermediate sections, whereby the width  72  of the flexure  13  is reduced by approximately the displacement d of the intermediate sections for relatively closer positioning of the flexure to a disk drive hub (not shown). 
   The invention thus provides an improved wireless suspension and suspension flexure design wherein strain energy build-up in the flexure during PSA/RSA adjustments and consequent difficult adjustments and post-adjustment, springback losses of precision are minimized by providing relief from the straight path, minimum material approach of the prior art to introduce curves into the flexure trace and plastic film laminate that offset or absorb the strains imposed by pitch and roll adjustments, making the fact of different materials in the flexure less significant. The invention further provides a local deflection in the flexure laminate to provide curvilinear shapes for stress take-up. The invention further provides for the deflection of the laminate toward the flexure central longitudinal axis and the bringing in of the flexure struts a like amount to narrow the width of the flexure, enabling closer approach of the suspension to the disk drive hub for increased disk drive capacity. 
   The foregoing objects are thus met.