Abstract:
A head arm assembly comprises a slider, a drive arm, a trace; and a load beam having a hinge portion and a slider mounting portion; wherein the slider mounting portion has a slider support portion to support flying attitude of the slider. The slider support portion has a slider mounting frame with a flexible lifter to maintain the slider position in a predetermined position. In the present invention, the flexible lifter has a spring structure. The load beam may further comprise a stiffener formed in a longitudinal direction of the head arm assembly. The invention also discloses a head stack assembly and a disk drive using the head arm assembly.

Description:
FIELD OF THE INVENTION 
   The present invention relates to head arm assemblies, head stack assemblies and disk drive units. 
   BACKGROUND OF THE INVENTION 
   Disk drives are information storage devices that use magnetic media to store data. A typical disk drive unit in related art comprises a magnetic disk and a head stack assembly (abbreviated as “HSA”, HSA with only one HGA is referred as “HAA” (head arm assembly)). The magnetic disk is mounted on a spindle motor which causes the magnetic disk to spin and a voice-coil motor (VCM) is provided for controlling the motion of the HSA and thus controlling slider (not labeled) on the HSA to move from track to track across the surface of the magnetic disk to read data from or write data to the magnetic disk. 
   Referring to  FIGS. 1 and 2 , a traditional HAA  13  comprises a drive arm  34 , a suspension  14  coupled with the drive arm  34 , and a slider  203  mounted on the suspension  14  (the suspension  14  with the slider  203  is referred as “HGA”). In the related art, as shown in  FIG. 1 , the suspension  14  comprises a flexure  32  and a load beam  33 . A dimple  329  is formed on the load beam  33  to support the flexure  32 . Referring to  FIG. 3 , when the slider  203  is mounted on the flexure  32 , the loading force keeps being applied to the center area of the slider  203  through the dimples  329  of the load beam  33 . 
   However, the traditional HAA has not a good shock performance because of its rather large and complicated structure. The structures of the traditional HAA not only influence its static performance, but also influence its dynamic performance. At the same time, with the disk drive units being widely used in many consumer electronics products, such as PDA, cell phone, digital camera, digital video, etc, the shock performance of the HAA used by the disk drive unit is more important for these precise products. In addition, the complicated structure of the HAA also makes the manufacturing and assembly process of the disk drive unit rather time-consuming, and accordingly increases the cost of manufacturing disk drive unit. 
   Hence, it is desired to provide a head arm assembly which can attain a better shock performance and overcome the above-mentioned shortcomings. 
   SUMMARY OF THE INVENTION 
   A main feature of the present invention is to provide a HAA with small mass and a good shock performance, and a disk drive unit having such a HAA. 
   Another feature of the present invention is to provide a HSA with small mass and a good shock performance, and a disk drive unit having such a HSA. 
   To achieve the above-mentioned features, a HAA of the present invention comprises a slider, a drive arm, a trace; and a load beam having a hinge portion and a slider mounting portion. The slider mounting portion has a slider support portion to support flying attitude of the slider. In the present invention, the slider support portion has a slider mounting frame with a flexible lifter to maintain the slider position in a predetermined position. The flexible lifter has a spring structure. In an embodiment, the load beam further comprises a stiffener formed in a longitudinal direction of the head arm assembly. As an embodiment, the stiffener is at least one rail formed between the hinge portion and a slider mounting portion. Each of the rails is formed by bending the side portion of the load beam. In a further embodiment, a lift tab extends from the hinge portion to front end of the slider mounting portion. 
   A head stack assembly comprises at least one head arm assemblies; wherein each of the head arm assemblies comprises a slider, a drive arm, a trace; and a load beam having a hinge portion and a slider mounting portion. In the present invention, the slider mounting portion has a slider support portion to support flying attitude of the slider. 
   A disk drive unit of the present invention comprises a disk, a spindle motor to spin the disk; and at least one head arm assemblies. Each of the head arm assemblies comprises a slider, a drive arm, a trace; and a load beam having a hinge portion and a slider mounting portion; wherein the slider mounting portion has a slider supporter to support flying attitude of the slider. 
   Compared with the prior art, firstly, because the HAA (HSA, disk drive) of the present invention has no additional flexure so as to omit the manufacturing process of the flexure and the assembly process with the load beam. Thus, it makes manufacturing HAA (HSA, disk drive) much easily and accordingly lows down the manufacturing cost thereof. In addition, omitting the additional flexure can also reduce the whole height and weight of the HAA (HSA, disk drive), that is, reducing the whole mass of the HAA (HSA, disk drive). This is because the related art must superpose the flexure with the load beam in a certain area for assembling them together, and accordingly the superposing portions of the flexure and the load beam will increase the whole height and weight of the HAA (HSA, disk drive). At the same time, reducing the weight of HAA (HSA, disk drive) will decrease its inertia and then attain a good shock performance. Furthermore, a stiffener, i.e. rails, is provided on the hinge portion so that the load beam is stiff enough to urge the slider to maintain a desired position relative to disk surface. 
   For the purpose of making the invention easier to understand, several particular embodiments thereof will now be described with reference to the appended drawings in which: 

   
     DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is an exploded, perspective view of a traditional HAA; 
       FIG. 2  is a perspective view of the assembled HAA of  FIG. 1 ; 
       FIG. 3  is a cross-sectional view of  FIG. 2  according to slider area of the HAA; 
       FIG. 4  is an exploded, perspective view of a HAA according to a first embodiment of the present invention; 
       FIG. 5  is a perspective view of the assembled HAA of  FIG. 4 ; 
       FIG. 6  is an enlarged, partial perspective view of  FIG. 5  according to a first angle of view; 
       FIG. 7  is an enlarged, partial perspective view of  FIG. 5  according to a second angle of view; 
       FIG. 8  is a cross-sectional view of  FIG. 5  according to slider area of the HAA; 
       FIG. 9  is a perspective view of an assembled HAA according to a second embodiment of the present invention; 
       FIG. 9A  is a perspective view of an assembled HAA according to a third embodiment of the present invention; 
       FIG. 9B  is an exploded, perspective view of a load beam of the HAA in  FIG. 9A ; 
       FIG. 9C  is a cross-sectional view of the HAA in  FIG. 9A  taken along line A-A; and 
       FIG. 10  is a perspective view of a disk drive unit according to an embodiment of the present invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   According to a first embodiment of the present invention, referring to  FIG. 4 , a HAA  13 ′ comprises a slider  203 ′, a drive arm  34 ′ and a load beam  33 ′ to load the slider  203 ′. The load beam  33 ′ has an integral structure and electric traces  309  formed thereon. 
   In the present invention, the load beam  33 ′ is an interconnecting piece where the electric traces  309  is integrated therewith and provide conductivity between a PCBA (not shown) and the slider  203 ′. In the invention, the load beam  33 ′ can be made by a laminate, such as trace suspension assembly (TSA), circuit integrated suspension (CIS), or flex suspension assembly (FSA). After the load beam  33 ′ are formed, it will be coupled to the drive arm  34 ′ by welding or other traditional method. 
   Referring to  FIG. 4 , the load beam  33 ′ comprises a hinge portion  391 , a slider mounting portion  392  and a connecting portion  399  to connect the hinge portion  391  and the slider mounting portion  392 . In the present invention, when a force is applied to the slider  203 ′, it will cause a shearing force to exert in the load beam  33 ′. As is known to all, an object is easily deformed when being applied to a shearing force while pressing force and/or pulling force only cause a little deformation of the object to which being applied. In order to transfer the shearing force exerted in the load beam  33 ′ into pressing force and/or pulling force, a stiffener is formed in a longitudinal direction of the load beam  33 ′. Thus, the deformation of the load beam  33 ′ can be reduced, accordingly, the stiffness of the load beam  33 ′ is increased greatly so that a load-unload operation can be successfully processed. In an embodiment, referring to  FIG. 6 , the stiffener is at least one rails, such as two rails  393 ,  394 , which is formed by bending two side portions of the connecting portion  399 . In addition, the rail  394  also serves as a lift tap which engages with and is lifted by a ramp  121  (see  FIG. 10 ). 
   Referring to  FIG. 4 , the slider  203 ′ has a plurality of electrical pads  209  on one end thereof. The slider mounting portion  392  has a slider support portion (not labeled) to support flying attitude of the slider  203 ′. In an embodiment of the invention, referring to  FIGS. 6 and 7 , the slider support portion has two side beams  409  each of which has an open end, and a slider mounting frame  402  to connect with the two side beams  409  by their open ends. The slider mounting frame  402  has a flexible lifter  400  to maintain the position of the slider  203 ′ upper than the position of the two beams  409 . The slider mounting frame  402  comprises two side beams  403  and a bottom beam  405  to connect with the side beams  403 . The flexible lifter  400  has a spring structure which extends from the bottom beam  405 . In an embodiment, the flexible lifter  400  comprises a suspension tongue  328  to support the slider  203 ′, and a connection part  401  to connect the bottom beam  405  with the suspension tongue  328 . In the present invention, because the load beam  33 ′ has a stiffener (e.g. two rails  393 ,  394 ) for improving the stiffness thereof so that the load beam  33 ′ is stiff enough to urge the slider  203 ′ to maintain a desired position relative to disk surface. In addition, the flexible lifter  400  has a spring structure to make the slider  203 ′ freely fly above the disk. 
   In the present invention, referring to  FIGS. 5 ,  6  and  7 , the suspension tongue  328  has a plurality of electrical pads  420  disposed on a predetermined position thereof corresponding to the electrical pads  209  of the slider  203 ′. Referring to  FIG. 8 , when the electrical pads  209  of the slider  203 ′ are positioned corresponding to the electrical pads  420  of the suspension tongue  328 , a plurality of metal balls (GBB or SBB, not shown) are provided to electrically connect the slider  203 ′ with the suspension tongue  328 . In the present invention, there is no dimple to support the suspension tongue  328 , however, the slider  203 ′ can still freely fly on the disk surface due to the spring structure of the flexible lifter  400 . 
   According to a second embodiment of the present invention, referring to  FIG. 9 , a HAA  13 ″ comprises a load beam  33 ″, a slider  203 ′ mounted thereon, and a drive arm  34 ′ coupled with the load beam  33 ″. The load beam  33 ″ comprises a hinge portion  391 ′, a slider mounting portion  392 ′ and a connecting portion  399 ′ to connect the hinge portion  391 ′ and the slider mounting portion  392 ′. A lift tab  332 ′ extends from the connecting portion  399 ′ to front end of the slider mounting portion  392 ′. Two rails  80  are formed from two side portions of the connecting portion  399 ′ to two side portions of the slider mounting portion  392 ′ in a longitudinal direction of the HAA  13 ″. In the embodiment, no other change except the above-mentioned is happened on the structure of the HAA  13 ″ comparing with the HAA  13 ′. Therefore, a detailed description thereof is omitted herefrom. 
   According to a third embodiment of the present invention, referring to  FIG. 9A , a HAA  3  comprises a load beam  63 , a slider  203 ′ mounted thereon, and a drive arm  34 ′ coupled with the load beam  63 . In an embodiment, referring to  FIGS. 9B-9C , the load beam  63  is made of FSA, which comprises a stainless steel substrate  67  and a flex on suspension (FOS) portion  62  on the stainless steel substrate  67 . The FOS portion  62  is attached to the stainless steel substrate  67  with adhesive or other traditional method. As an embodiment, the FOS portion  62  is mainly made of polyimide (PI), which is formed a PI layer (insulation layer); electric traces  309  are built on the PI layer. In the embodiment, the load beam  63  comprises a hinge portion  75 , a slider mounting portion  73  and a connecting portion  72  to connect the hinge portion  75  and the slider mounting portion  73 . A lift tab  78  extends from the connecting portion  72  to front end of the slider mounting portion  73 . Also, two rails  66  are formed from two side portions of the connecting portion  72  to two side portions of the slider mounting portion  73  in a longitudinal direction of the HAA  3 . In the embodiment, the slider mounting portion  73  comprises a slider support portion  79  which has a flexible lifter  70 . The flexible lifter  70  comprises a front tongue part  69  and a rear tongue part  68 . The front tongue part  69  is connected with the connecting portion  72  by two side beams  65 , while the rear tongue part  68  extends from the connecting portion  72  directly. A dimple  61  is formed on the end of the rear tongue part  68  adjacent to the front tongue part  69 . When the slider  203 ′ is mounted on the load beam  63 , the dimple  61  leans against the FOS portion  62  and then supports the slider  203 ′ to maintain the position of the slider  203 ′ upper than the position of the two side beams  65 . Obviously, the load beam can also be made of CIS or TSA, which has a similar structure to the load beam  63 . In the present invention, a HSA also can be formed by assembled two or more HAA of the present invention (e.g. HAA  13 ′,  13 ″ or  3 ). 
   Referring to  FIGS. 4-9C , in the present invention, the slider  203 ′ are coupled with the load beam  63 ,  33 ′ or  33 ″ by epoxy glue or an epoxy-free bonding method. In an embodiment of the present invention, connecting the slider  203 ′ with the load beam  63 ,  33 ′ or  33 ″ electrically are performed as follows (using the load beam  33 ′ as an example): using a plurality of metal balls (GBB or SBB) to electrically connect the electrical pads  209  of the slider  203 ′ with the electrical pads  420  so as to electrically connect the slider  203 ′ with the electric multi-traces  309  of the load beam  33 ′. Through the electric multi-traces  309 , the slider  203 ′ can be connected with a PCBA (not shown). 
   In the present invention, referring to  FIG. 10 , a disk drive unit  100 ′ of the present invention can be attained by assembling a disk drive housing  90 , a disk  101 ′, a spindle motor  102 ′ with the HAA  13 ′ (also can be HAA  3 ,  13 ″ or HSA) of the present invention. Because the structure and/or assembly process of a disk drive unit by using the HAA  13 ′ (also can be HAA  3 ,  13 ″ or HSA) of the present invention are well known to persons ordinarily skilled in the art, a detailed description of such structure and assembly is omitted herefrom. 
   Comparing with the related art, the present invention omits an additional flexure so as to omit the manufacturing process of the flexure and the assembly process with the load beam. Thus, it makes manufacturing HAA (HSA, disk drive) much easily and accordingly lows down the manufacturing cost thereof. In addition, omitting the additional flexure can also reduce the whole height and weight of the HAA (HSA, disk drive). This is because the related art must superpose the flexure with the load beam in a certain area for assembling them together, and accordingly the superposing portions of the flexure and the load beam will increase the whole height and weight of the HAA (HSA, disk drive). At the same time, reducing the weight of HAA (HSA, disk drive) will decrease its inertia and then attain a good shock performance.