Load beam nesting structure for head stack assembly protection

Abstract

An embodiment of a head stack assembly arm is disclosed. The head stack assembly arm includes an upper nested load beam including a lift tab having an inner edge. The head stack assembly arm includes a lower nested load beam including a lift tab having an inner edge. The inner edge of the lower nested load beam is a different size than the inner edge of the upper nested load beam.

Description

[Technical field]

[0001] The present invention relates generally to an improved head stack assembly (HSA) arm, and more particularly to a nesting structure for the head stack assembly. [Background technology]

[0002] A typical hard disk drive includes a head disk assembly (HDA) and a printed circuit board assembly (PCBA) attached to the hard disk drive base of the HDA. The HDA typically includes a disk drive base and a disk drive cover that together enclose at least one disk (e.g., a magnetic disk, a magneto-optical disk, or an optical disk), a spindle motor for rotating the disk, and a head stack assembly (HSA). The PCBA contains electronics for controlling the rotation of the spindle motor and the position of the HSA, and for providing a data transfer channel between the hard disk drive and its host.

[0003] The HSA includes an actuator arm having an actuator arm tip to which a head gimbal assembly (HGA) is attached, typically by a process known as swaging. The HGA typically includes a read / write head and a suspension assembly that suspends or supports the read / write head.

[0004] In a typical swaging connection, the thickness of the actuator arm must be sufficient to accommodate the suspension. As the number of disks and suspensions in a hard disk drive increases to increase capacity, the thickness of the head stack arm, the ramp pitch, and the gap between the disks decrease to accommodate the disks and suspensions. As the thickness of the arm decreases, the gap between the load beams decreases. A decrease in the gap between the load beams can endanger the disk drive because the load beams can contact each other during lift-off and deactivation shocks. Such metal-to-metal contact can cause metal particles to fly onto the disk media, causing drive failure. Thus, the amount by which the distance between the disks can be decreased is limited, limiting the recording density of the unit.

[0005] Therefore, there is a need for an improved head stack assembly, and more specifically, an improved low profile design that maximizes the gap between the suspensions as the thickness of the actuator arm decreases. Summary of the Invention

[0006] Described herein are examples of head stack assembly (HSA) arms. The HSA arm may include an upper nested load beam including a lift tab having an inner edge. The HSA arm may also include a lower nested load beam including a lift tab having an inner edge. The inner edge of the lower nested load beam is sized differently than the inner edge of the upper nested load beam. In some embodiments, the upper nested load beam and the lower nested load beam are coupled with a rigid anchor arm.

[0007] In some embodiments, the load beam of the lower nested structure is coupled to the rigid anchor arm via a first base plate. Alternatively, the load beam of the upper nested structure is coupled to the rigid anchor arm via a second base plate. The load beam of the upper nested structure and / or the load beam of the lower nested structure may further include a slider connected to the load beam via a flexure at a distal end. The load beam of the upper nested structure and / or the load beam of the lower nested structure may also include a pair of side rails configured to have a predetermined stiffness and load bearing capacity.

[0008] In some embodiments, the lift tab of the upper nested load beam is formed with a lift tab width that is smaller than the lift tab of the lower nested load beam. In some embodiments, the lift tab of the upper nested load beam is formed with a lift tab width that is larger than the lift tab of the lower nested load beam. In additional embodiments, the lift tab of the upper nested load beam is configured to have a width that is larger than the lift tab of the lower nested load beam, and the lift tab of the upper nested load beam and the lift tab of the lower nested load beam are configured to nest with each other.

[0009] In another aspect, a head stack assembly (HSA) arm is disclosed having an upper nested load beam including a lift tab with an inner edge and a lower nested load beam including a lift tab with an inner edge, the lower nested load beam and the upper nested load beam being asymmetric, the upper nested load beam and the lower nested load beam being coupled with a rigid anchor arm.

[0010] In some embodiments, the inner edge of the load beam of the upper nested structure is aligned with the center of the inner edge of the load beam of the lower nested structure. Additionally, the load beam of the inner edge of the lower nested structure may be aligned with the center of the inner edge of the load beam of the upper nested structure.

[0011] In yet another aspect, a head stack assembly arm is disclosed that includes a first suspension including a load beam and at least one side rail configured to have rigidity and load bearing capacity, and a second suspension including a load beam and at least one side rail configured to have rigidity and load bearing capacity. At least one side rail of the first suspension and at least one side rail of the second suspension are asymmetric. In some embodiments, at least one side rail of the first suspension and at least one side rail of the second suspension are staggered. In some embodiments, at least one side rail of the first suspension is sized differently than at least one side rail of the second suspension. In some embodiments, the first and / or second suspension includes a base plate connected to the load beam at a proximal end. In some embodiments, the second suspension includes a base plate connected to the load beam at a proximal end. The first and / or second suspension may be attached to a rigid anchor arm at a proximal end. In some embodiments, the load beam of the first suspension includes a lift tab having an inner edge and the load beam of the second suspension includes a lift tab having an inner edge. The inner edge of the load beam of the first suspension may be of a different size than the inner edge of the load beam of the second suspension.

[0012] Other features and advantages of the embodiments of the present disclosure will become apparent from the accompanying drawings and from the detailed description that follows. Embodiments of the present disclosure are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like reference numerals indicate similar elements. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 illustrates an upper telescoping load beam and a lower telescoping load beam of an exemplary head stack assembly arm according to an alternative embodiment of the present disclosure. [Diagram 2] FIG 2A shows a perspective view of FIG 1 with an upper load beam lift tab having a smaller footprint than the lower load beam lift tab according to one embodiment of the present disclosure. FIG 2B shows a side view of an upper ramp design and a lower ramp design for the nested suspension to park on during a non-operational mode according to one embodiment of the present disclosure. FIG 2C shows a cross section of the upper load beam lift tab, lower load beam lift tab, and inner radius edge of the nested suspension at a point along the ramp according to one embodiment of the present disclosure. [Diagram 3] FIG. 3 illustrates an example asymmetric load beam in upper and lower nested configurations of an example head stack assembly arm according to one embodiment of the present disclosure. [Figure 4] FIG. 4 illustrates a side view of the upper and lower load beams assembled on the head stack arm according to one embodiment of the present disclosure. [Diagram 5] FIG. 5 illustrates an exemplary head stack assembly arm having asymmetric load beam rails according to one embodiment of the present disclosure. [Figure 6] FIG. 6 illustrates an exemplary head stack assembly arm having staggered load beam rails according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Described herein are embodiments of a head stack assembly (HSA) arm with nested suspension. The HSA arm may include a load beam in an upper nesting configuration including a lift tab having an inner edge. The HSA arm may include a load beam in a lower nesting configuration including a lift tab having an inner edge. The inner edge of the lower nesting configuration load beam is a different size than the inner edge of the upper nesting configuration load beam.

[0015] FIG. 1 illustrates an upper nested load beam 212 and a lower nested load beam 214 of an exemplary head stack assembly (HSA) arm according to one embodiment of the present disclosure. The upper nested load beam 212 includes an upper tab 203 including a lift tab 207 having an inner edge 211. The lower nested load beam 214 includes a lower tab 205 including a lift tab 209 having an inner edge 213. The lift tab 207 may be formed with a lift tab width C that is smaller than the lift tab width D of the lift tab 209. As a result, the lift tab 207 can nest into the lift tab 209 during an impact event. Because the contact point is within the inner edge 213, the gap A between the lift tabs may be increased compared to conventional designs to provide a more generous clearance.

[0016] FIG. 2A shows a perspective view of FIG. 1 showing the upper and lower load beam lift tabs according to one embodiment of the present disclosure. The upper load beam lift tab is narrower than the lower load beam lift tab so that the profile of the upper load beam lift tab appears to be within the profile of the lower load beam lift tab. FIG. 2B shows a side view of the suspension ramp design of the nested suspension where the suspension parks during non-operational mode. The upper ramp 301 and the lower ramp 302 are configured at the edge of the rotating disk. The suspension slides onto the ramps and simultaneously stops on the horizontal surface of the ramps 301, 302, as in conventional designs. FIG. 2C shows a cross section of the upper load beam lift tab, the lower load beam lift tab, and the inner radial edge of the nested suspension at a point along the ramp. Initially, the narrower upper load beam lift tab engages with ramp #1 at the proximal end and the wider lower load beam lift tab engages with ramp #2 at the proximal end. According to one embodiment of the present disclosure, the two lift tabs slide along the ramp to the horizontal distal end and remain in the non-operational mode.

[0017] In conventional designs, the upper and lower load beams have the same lift tab width and the upper lift tab impacts edge-to-edge with the half-moon shaped portion of the lower lift tab under an impact event. In comparison, in some embodiments, the half-moon shaped portion of the upper load beam lift tab is narrower than the half-moon shaped portion of the lower load beam lift tab and the half-moon shaped portion of the upper lift tab may impact the inner surface of the half-moon shaped portion of the lower lift tab during an impact event. As a result, the present invention allows the upper lift tab to travel a greater vertical distance under an impact event, as shown in FIG. 1, which reduces the chance of lift tab contact and reduces the generation of metal particles.

[0018] 3 illustrates an exemplary asymmetric upper nested load beam 412 and a lower nested load beam 414 of an exemplary head stack assembly arm 500 according to one embodiment of the present disclosure. The upper nested load beam 412 includes an upper tab 403 including a lift tab 407 having an inner edge 411. The lower nested load beam 414 includes a lower tab 405 including a lift tab 409 having an inner edge 413. The upper nested load beam 412 and the lower nested load beam 414 are asymmetric such that the inner edge 411 of the lift tab 407 is substantially aligned with a center of the lift tab of the inner edge 413. Additionally, the inner edge 413 of the lower lift tab 409 is substantially aligned with a center of the lift tab 407 of the inner edge 411.

[0019] As a result, the upper lift tab 407 and the lower lift tab 409 can nest within one another during an impact event. Because the contact points are at the center of each half-moon portion, the lift tab-to-lift tab (LT-LT) gap B' can be enlarged to allow for more clearance compared to conventional designs in which the contact points between the upper and lower lift tabs are at the edges of the lift tab half-moon portions.

[0020] 4 illustrates a side view of an exemplary head stack assembly (HSA) arm 600 having nested load beam designs 620, 640, according to one embodiment of the present disclosure. The HSA arm 600 includes a distal end 20 and a proximal end 10. The HSA arm 600 includes a first suspension 50 and a second suspension 60 adjacent to the first suspension. The two adjacent suspensions 50, 60 may be attached to a rigid anchor arm 113 at the proximal end 10. The two adjacent suspensions 50, 60 may be positioned to move between an upper nested load beam and a lower nested load beam at the distal end 20.

[0021] The first suspension 50 includes a load beam 620 and a base plate 115 or connecting member connected to the load beam 620 at a proximal end 10. The first suspension 50 may also include a slider or read / write transducer head, as known in the art, connected to the load beam 620 by a flexure at a distal end 20.

[0022] The second suspension 60 includes a load beam 640 and a base plate 116 or connecting member connected to the load beam 640 at a proximal end 10. The second suspension 60 may also include a slider or read / write transducer head, as known in the art, connected to the load beam 640 via a flexure at a distal end 20.

[0023] The load beam 620 of the first suspension 50 may include a pair of side rails 118 configured to provide the first suspension 50 with a predetermined stiffness and load bearing capacity. The load beam 640 of the second suspension 60 may include a pair of side rails 119 configured to provide the second suspension 60 with a predetermined stiffness and load bearing capacity.

[0024] In some embodiments, the load beams 620, 640 are made from stainless steel. In some embodiments, the pair of side rails 118, 119 face away from each other to accommodate the reduced actuator arm thickness Ω. In other embodiments, the pair of side rails 118, 119 face inward and the rigid anchor arm 113 has a thickness to accommodate the load beams 620, 640.

[0025] Each of the load beams 620, 640 has a base plate or connection element 115, 116 associated therewith, respectively. As the number of disks and suspensions increases to increase the capacity of the hard disk drive, the thickness Ω of the rigid anchor arm 113 decreases to accommodate the disks and suspensions. The arm thickness Ω is one of the main parameters of the gap between the load beams, including the load beam rail gap A. The arm thickness Ω is also the main parameter that defines the lift tab gap E between the lift tabs 126, 128. As the thickness Ω of the rigid anchor arm 113 decreases, the gap A between the load beams also decreases. The load beams 620, 640 constructed according to the above-mentioned technology can reduce the arm thickness Ω, ramp pitch, and gap between disks compared to current technology, allowing the hard disk drive to accommodate more disks and occupy less space than current technology.

[0026] FIG. 5 illustrates a cross-sectional view of an exemplary head stack assembly arm 113 with the load beam rails of FIG. 4. In a conventional design, the rails of the upper load beam and the rails of the lower load beam may contact each other during an impact event due to the small gap between the rails. FIG. 5 also illustrates a nested load beam design with rail gap H for an exemplary head stack assembly arm 800 with load beams 820, 840 according to one embodiment of the present disclosure. Compared to the conventional design, the offset of the rails 825, 835 of the upper load beam may move a greater distance during an impact event before contacting the inner surface of the lower rails 845, 815, even though they do not contact the rails 845, 815 of the lower load beam. Thus, the value of H is larger than the conventional rail gap where edges contact.

[0027] 6 illustrates another exemplary head stack assembly arm with asymmetric nested load beam rails according to one embodiment of the present disclosure. FIG. 6 illustrates an exemplary head stack assembly arm with load beams 920, 940 according to one embodiment of the present disclosure. The offset of the upper load beam rails 925, 935 compared to conventional contacts allows the rails 945, 915 of the lower load beam to not come into contact and travel a much greater distance during an impact event than conventional designs, helping to reduce the chance of contact between the upper and lower rails and metal particles generated by impact.

[0028] It should be understood that terms such as "upper," "lower," "above," "best," and x-, y-, and z-directions used herein are terms of convenience to indicate the spatial relationship of parts relative to one another, rather than any particular spatial or gravitational orientation. These terms are therefore intended to encompass an assembly of components, whether the assembly is oriented in the particular orientation shown in the drawings and described herein, or upside down from that orientation, or any other rotational variation.

[0029] It should be understood that the term "the present disclosure" as used herein is not to be interpreted as meaning that only a single disclosure having a single essential element or group of elements is presented. Similarly, it should be understood that the term "the present disclosure" encompasses several separate innovations, each of which may be considered as a separate disclosure. Although the present disclosure has been described in detail with reference to the preferred embodiment and drawings thereof, it will be apparent to those skilled in the art that various adaptations and modifications of the embodiments of the present disclosure may be accomplished without departing from the spirit and scope of the present disclosure.

Claims

1. an upper nested load beam including a lift tab having an inner edge; a lower nested load beam including a lift tab having an inner edge, the inner edge of the lower nested load beam being a different size than the inner edge of the upper nested load beam; The load beam of the upper telescoping structure and the load beam of the lower telescoping structure are coupled to a rigid anchor arm, a head stack assembly arm.

2. The head stack assembly arm of claim 1 , wherein the load beam of the lower nesting structure is coupled to the rigid anchor arm via a first base plate.

3. 3. The head stack assembly arm of claim 2, wherein the load beam of the lower nested structure includes a slider connected to the load beam at a distal end via a flexure.

4. 3. The head stack assembly arm of claim 2, wherein the load beam of the lower nesting structure includes a pair of side rails configured to have a predetermined stiffness and load bearing capacity.

5. The head stack assembly arm of claim 1 , wherein the load beam of the upper telescoping structure is coupled to the rigid anchor arm via a second base plate.

6. 6. The head stack assembly arm of claim 5, wherein the load beam of the upper nested structure includes a slider connected to the load beam at a distal end via a flexure.

7. 6. The head stack assembly arm of claim 5, wherein the load beam of the upper telescoping structure includes a pair of side rails configured to have a predetermined stiffness and load bearing capacity.

8. 2. The head stack assembly arm of claim 1, wherein the lift tab of the load beam of the upper nested structure is formed with a lift tab width that is smaller than the lift tab of the load beam of the lower nested structure.

9. 2. The head stack assembly arm of claim 1, wherein the lift tab of the load beam of the upper nested structure is formed with a lift tab width greater than the lift tab of the load beam of the lower nested structure.

10. 2. The head stack assembly arm of claim 1, wherein the lift tab of the load beam of the upper nested structure is configured to have a width greater than the lift tab of the load beam of the lower nested structure, and the lift tab of the load beam of the upper nested structure and the lift tab of the load beam of the lower nested structure are configured to nest within each other.

11. an upper nested load beam including a lift tab having an inner edge; a lower nested load beam including a lift tab having an inner edge, the lower nested load beam and the upper nested load beam being asymmetric; The load beam of the upper telescoping structure and the load beam of the lower telescoping structure are coupled to a rigid anchor arm, a head stack assembly arm.

12. The head stack assembly arm of claim 11 , wherein the inner edge of the load beam of the upper nested structure is aligned with a center of the inner edge of the load beam of the lower nested structure.

13. The head stack assembly arm of claim 11 , wherein the load beam of the inner edge of the lower nested structure is aligned with a center of the inner edge of the load beam of the upper nested structure.

14. a first suspension including a load beam and at least one side rail configured to have stiffness and load bearing capacity; a second suspension including a load beam and at least one side rail configured to have stiffness and load bearing capacity; The at least one side rail of the first suspension and the at least one side rail of the second suspension are asymmetric.

15. The head stack assembly arm of claim 14 , wherein the at least one side rail of the first suspension and the at least one side rail of the second suspension are staggered.

16. The head stack assembly arm of claim 14 , wherein the at least one side rail of the first suspension is a different size than the at least one side rail of the second suspension.

17. The head stack assembly arm of claim 14 , wherein the first suspension includes a base plate connected at a proximal end to the load beam.

18. The head stack assembly arm of claim 14 , wherein the second suspension includes a base plate connected at a proximal end to the load beam.

19. The head stack assembly arm of claim 14 , wherein the first suspension is attached at a proximal end to a rigid anchor arm.

20. The head stack assembly arm of claim 14 , wherein the second suspension is attached at a proximal end to a rigid anchor arm.

21. the load beam of the first suspension including a lift tab having an inner edge; the load beam of the second suspension including a lift tab having an inner edge; 15. The head stack assembly arm of claim 14, wherein the inner edge of the load beam of the first suspension is sized differently than the inner edge of the load beam of the second suspension.

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