Load beam including slit features - Patent application
Patent Information
- Application Number
- JP2024503423
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-07-15
- Filing Date
- 2022-07-18
- Publication Date
- 2025-07-25
- Estimated Expiration
- 2042-07-18
AI Technical Summary
Conventional load beams in hard disk drives face issues with buckling due to excessive deformation and increased dust pan formation angles, which can lead to structural instability and performance degradation.
The introduction of a slit feature around the tip weld in the load beam design, shifting the dust pan formation line towards the dimple, reduces buckling by allowing a smaller dust pan formation angle and maintaining lift tab offset height, thereby enhancing structural integrity.
The slit design in the load beam reduces rail buckling and maintains structural rigidity, ensuring stable operation and improved performance by minimizing deformation and maintaining desired lift characteristics.
Smart Images
Figure 00000000_0000_ABST
Abstract
Description
[Technical field]
[0001] FIELD OF THE DISCLOSURE The present disclosure relates to the field of suspensions for hard disk drives. More specifically, the present disclosure relates to the field of load beams for hard disk drives. [Background technology]
[0002] Disk storage devices use rotating disks to store information. Disk storage devices typically include a frame that provides mounting points and orientation for other components, and a spindle motor attached to the frame to rotate the disk. A head slider includes a read / write head for writing data to and reading data from the disk surface. The head slider is supported and properly oriented relative to the disk by a suspension that provides both the force and compliance required for proper head slider operation. As the disk in the storage device rotates under the head slider and head suspension, the air above the disk also rotates, thus creating an air bearing that works with the aerodynamic design of the suspension to create a lift force. The lift force is countered by the spring force of the suspension to position the head slider at a desired height and alignment above the disk, called the "flying height."
[0003] A suspension for a disk drive includes a load beam and a flexure. The load beam typically includes a mounting region for mounting the suspension to an actuator of the disk drive, a rigid region, and a spring region between the mounting region and the rigid region. The spring region provides a spring force that suppresses aerodynamic lift generated on the suspension during drive operation as described above. The flexure typically includes a gimbal region having a slider mounting surface to which a head slider is attached. The gimbal region is elastically movable relative to the rest of the flexure in response to aerodynamic forces generated by an air bearing. The gimbal region allows the head slider to move in pitch and roll directions to follow variations in the disk surface. Summary of the Invention
[0004] Described herein is an improved load beam. According to some embodiments of the present disclosure, the load beam comprises a main surface including a distal end and a proximal end, the distal end including a tip weld, a dustpan, and a lift tab, side rails extending from the main surface and the dustpan, and a slit disposed in the main surface around the tip weld.
[0005] According to some embodiments of the present disclosure, the convex portion of the slit is distal to the tip weld. According to some embodiments of the present disclosure, the dustpan forming line is disposed through the tip weld.
[0006] According to some embodiments of the present disclosure, the dustpan forming angle θ may be between 15 and 25°. According to some embodiments of the present disclosure, the slit is semi-circular in shape around the tip weld.
[0007] According to some embodiments of the present disclosure, the slit is U-shaped around the tip weld. According to some embodiments of the present disclosure, the dustpan includes a proximal end and a distal end, the proximal end including a dustpan forming line and the distal end including a lift tab.
[0008] According to some embodiments of the present disclosure, the lift tab is located distally from the dustpan. According to some embodiments of the present disclosure, the major surface includes dimples.
[0009] According to some embodiments of the present disclosure, the major surface includes a window. A suspension comprising a load beam according to some embodiments of the present disclosure is also provided.
[0010] While multiple embodiments are disclosed, still other embodiments of the present disclosure will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the present disclosure. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive.
[0011] To illustrate how the above and other advantages and features of the present disclosure can be obtained, the above principles will be more particularly described by reference to specific examples shown in the accompanying drawings. These drawings depict only exemplary aspects of the present disclosure and therefore should not be considered as limiting the scope of the disclosure. The principles will be described and explained with further specificity and detail using the following drawings: [Brief description of the drawings]
[0012] [Figure 1A] FIG. 2 illustrates a top view of an exemplary suspension according to some embodiments of the present disclosure. [Figure 1B] FIG. 2 illustrates a bottom view of an exemplary suspension according to some embodiments of the present disclosure. [Diagram 2] FIG. 2 illustrates a top view of an exemplary load beam according to some embodiments of the present disclosure. [Diagram 3]FIG. 2 is a side view of an exemplary load beam according to some embodiments of the present disclosure. [Figure 4] FIG. 13 is a top view of a second exemplary load beam according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0013] A load beam is described herein. A load beam according to some embodiments of the present disclosure is part of a suspension for a magnetic disk drive unit. The disk drive unit includes a rotating magnetic or optical disk, which includes a pattern of magnetic ones and zeros that constitute the data stored on the disk drive. The magnetic or optical disk is driven by a drive motor. The disk drive unit according to some embodiments includes a suspension having a load beam, a base plate, and a gimbal, with a head slider attached to the gimbal proximate to a distal end of the gimbal. The proximal end of the suspension or load beam is the end that is supported, i.e., the end closest to the base plate that is swaged or otherwise attached to the actuator arm. The distal end of the suspension or load beam is the end opposite the proximal end, i.e., the distal end is the cantilevered end.
[0014] The gimbal is coupled to a base plate, which in turn is coupled to a voice coil motor. The voice coil motor is configured to move the suspension in an arc to position the head slider over the correct data track on the magnetic disk. The head slider is mounted on a gimbal, which allows the slider to pitch and roll to follow the appropriate data track on the rotating magnetic disk, thus tolerating such variations without degrading performance. Such variations typically include disk vibrations, inertial events such as bumping, and disk surface irregularities.
[0015] In some embodiments, the gimbals described herein are part of a dual stage actuation (DSA) suspension. The DSA suspension can include a base plate and a load beam. The load beam includes a gimbal. The gimbal can include an attached actuator and a gimbal assembly. The actuator is operable to directly act on the gimbal-type assembly of the DSA suspension configured to include a read / write head slider.
[0016] In some embodiments, the gimbal may include at least one actuator joint configured to receive an actuator. The gimbal, according to some embodiments, includes two actuator joints located on opposite sides of the gimbal. Each actuator joint includes an actuator mounting shelf.
[0017] In some embodiments, each actuator spans a respective gap in the actuator joint. The actuators are affixed to the tongue of the slider by adhesive. The adhesive may include conductive or non-conductive epoxy strategically applied to each end of the actuator. Positive and negative electrical connections from the actuators to the gimbal can be made by a variety of techniques. When actuated, the actuators expand and contract to move a read / write head attached to the distal end of the suspension, thereby changing the length of the gap between the attached ends.
[0018] In some embodiments, the suspension may be configured as a single-stage actuation suspension, a two-stage actuation device, a three-stage actuation device, or other configurations. In some embodiments, the three-stage actuation suspension includes actuators disposed simultaneously on the mount plate area and the gimbal, respectively. Possibly, any variation of actuators may be incorporated onto the suspension for purposes of the embodiments disclosed herein. In other words, the suspension may include more or less components than those shown without departing from the scope of the present disclosure. However, the components shown are sufficient to disclose an exemplary embodiment for implementing the disclosed principles.
[0019] As shown in more detail in Figures 1 and 2, the suspension 10 includes a number of separate components attached together. The suspension 10 includes a load beam 12 to which a flexure is attached. The load beam 12 is a generally flat structure formed from a metal substrate, such as stainless steel. The load beam 12 includes a major surface 14 (e.g., a top or bottom surface of the load beam 12) that is flat and extends across a majority of the load beam 12. The load beam 12 is generally rigid such that separate portions of the major surface 14 do not move relative to one another during normal operation of the suspension 10. The major surface is interrupted by various features, such as windows 38 as shown in Figure 2. The load beam 12 may also include other windows. The windows are open on a first side (e.g., top) and a second side (e.g., bottom) of the load beam 12 by extending through the substrate of the load beam 12. The windows may be used for alignment during assembly, the windows may lighten and / or strengthen the load beam 12, and / or other components may extend through one or more windows.
[0020] The load beam 12 includes a mounting region at its proximal end to which a base plate is attached. The mounting region and base plate are attached to an actuator arm of a disk drive unit in a known manner. The load beam 12 further includes a rigid region at a distal portion of the load beam 12 and a spring region located proximal to the rigid region and distal to the mounting region. A flexure is attached to the rigid region of the load beam 12 and provides a resilient connection between the load beam 12 and the slider.
[0021] The spring region of the load beam 12 provides the desired gram load to counter the force applied to the slider by the air bearing generated by the rotating disk. To this end, the spring region may include a preformed bend or radius that provides the precise gram load force. The gram load is transferred to the flexure through the rigid region of the load beam 12. A dimple 9 may extend between the rigid region of the load beam 12 and the flexure to provide a transfer point for the gram load.
[0022] In some embodiments, the load beam 12 includes side rails 22, 24. In some embodiments, the side rails 22, 24 have high lateral stiffness to achieve high torsional and sway frequencies. In some embodiments, the side rails 22, 24 are made of stainless steel. In some embodiments, the side rails 22, 24 extend generally perpendicularly from the load beam 12. In some embodiments, the load beam 12 and the side rails 22, 24 comprise a unitary piece. In some embodiments, the load beam 12 and the side rails 22, 24 comprise a unitary piece made of stainless steel.
[0023] In some embodiments, the distal end of the load beam 12 includes a dustpan 18 and a lift tab 16. In some embodiments, the dustpan 18 includes a proximal end 26 and a distal end 28. In some embodiments, the lift tab 16 is located at the distal end 28 of the dustpan 18. In other words, the lift tab 16 is distal to the dustpan 18. In some embodiments, the proximal end 26 defines a dustpan formation line 30 between the dustpan 18 and the major surface 14 of the load beam 12.
[0024] In some embodiments, the side rails 22, 24 also extend from the dustpan 18. In some embodiments, the side rails 22, 24 extend generally perpendicularly from the dustpan 18.
[0025] In some embodiments, the distal end 28 of the load beam 12 further includes a tip weld 20. In some embodiments, the tip weld 20 is disposed on the flat major surface 14. The dustpan-shaped forming line in a conventional load beam (without slits) is disposed distal to the tip weld. In some embodiments of the present disclosure, the dustpan-shaped forming line 30 extends through the tip weld 20. In other words, the dustpan-shaped forming line 30 is shifted toward the dimple 9 compared to a conventional load beam (without slits). For some embodiments, the dustpan-shaped forming line 30 is shifted toward the dimple 9 by 0.05 mm to 0.5 mm compared to a conventional load beam. As shown in FIG. 2, the dustpan-shaped forming line 30 is shifted toward the dimple 9 by 0.1 mm compared to the dustpan-shaped forming line in a conventional load beam (without slits).
[0026] In some embodiments, the distal end of the load beam 12 further includes a slit 32 disposed about the tip weld 20. In some embodiments, the slit 32 is disposed in the flat major surface 14. In some embodiments, the slit 32 is semicircular in shape, as shown in FIG. 2. In some embodiments, the slit 32 is U-shaped, as shown in FIG. 4. In some embodiments, the convex portion of the slit 32 (e.g., semicircular or U-shaped) is distal to the tip weld 20.
[0027] In a conventional load beam, the load beam dustpan line is shifted toward the lift tab (i.e., distal to the tip weld) due to the additional tip weld at the distal end of the load beam. To maintain the same load beam length, the dustpan angle is increased to achieve the target lift tab offset height. However, in a conventional load beam, an increased dustpan angle can easily cause excessive deformation of the load beam material, potentially causing buckling of the load beam rail.
[0028] Without being bound to any particular theory, the improved load beam 12 reduces buckling problems of the side rails 22, 24 of the load beam 12. The slits 32 allow the dustpan forming line 30 to be shifted toward the dimple 9 (i.e., away from the lift tab 16) as compared to a conventional load beam. The slits 32 also allow the dustpan forming angle θ to be smaller as compared to a conventional load beam (without the slit), thereby reducing the buckling problems of the side rails at the dustpan forming line in a conventional load beam.
[0029] In some embodiments, the lift tab offset height h can be maintained while the dustpan angle θ can be reduced by 2.0° to 8.0° compared to the dustpan angle θ in a conventional load beam (without slits). In some embodiments, the dustpan angle θ can be reduced by 4.0° to 8.0° compared to the dustpan angle θ in a conventional load beam (without slits). In other words, the dustpan angle θ of the exemplary embodiment of FIG. 2 is smaller than the dustpan angle θ of a conventional load beam (without slits). As shown in FIG. 3, the slits 32 allow the lift tab offset height h to be maintained (which height h is 0.250 mm for some embodiments) while the dustpan angle θ can be reduced to 24.7°. In some embodiments, the dustpan angle θ can be 15 to 25°, 18 to 25°, or 20 to 25°. In addition, since the slits 32 are narrow and disposed on the flat main surface 14, the rigidity of the lift tab 16 can be maintained.
[0030] FIG. 4 illustrates a second exemplary embodiment of the load beam 212. As shown in FIG. 4, the dustpan forming line 230 is shifted toward the dimple 229 compared to the dustpan forming line in a conventional load beam (without slits). In some embodiments, the dustpan forming line 230 is shifted toward the dimple 229 more (i.e., more than 0.1 mm) compared to the dustpan forming line in a conventional load beam (without slits) than in the exemplary embodiment of FIG. 2. In some embodiments, the distal end of the load beam 212 further includes a slit 232 disposed about the tip weld 220. In some embodiments, the slit 232 is disposed in the flat major surface 214. In some embodiments, the slit 232 is U-shaped, as shown in FIG. 4. In some embodiments, the convex portion of the slit 232 is distal to the tip weld 220. In some embodiments, the load beam 212 also includes a window 238.
[0031] In some embodiments, the lift tab offset height h can be maintained while the dustpan angle θ can be reduced by 2.0° to 8.0° compared to the dustpan angle θ in a conventional load beam (without slits). In some embodiments, the dustpan angle θ can be reduced by 4.0° to 8.0° compared to the dustpan angle θ in a conventional load beam (without slits). In some embodiments, the dustpan angle θ can be reduced (i.e., more than 4.0°) compared to the dustpan angle θ in a conventional load beam (without slits) than the exemplary embodiment of FIG. 2. In other words, the dustpan angle θ in the exemplary embodiment of FIG. 4 is less (i.e., less than 24.7°) than the dustpan angle θ in a conventional load beam (without slits) as well as the dustpan angle θ in the exemplary embodiment of FIG. 2. In some embodiments, the dustpan angle θ can be 15 to 25°, 18 to 25°, or 20 to 25°. Without being bound to any particular theory, the improved load beam 212 reduces the problem of buckling of the side rails 222 , 224 of the load beam 212 .
[0032] Load beams according to the embodiments described herein are configured for use with hard drive suspensions, including those described herein. Although multiple embodiments are disclosed, still other embodiments within the scope of the present disclosure will be apparent to those skilled in the art from the Detailed Description provided herein, which shows and describes exemplary embodiments. Therefore, the drawings and Detailed Description should be considered exemplary in nature and not restrictive. Features and modifications of the various embodiments are discussed herein and shown in the drawings. Although multiple embodiments are disclosed, still other embodiments of the present disclosure will be apparent to those skilled in the art from the Detailed Description provided below, which shows and describes exemplary embodiments of the present disclosure. Therefore, the drawings and Detailed Description should be considered exemplary in nature and not restrictive.
Claims
1. A load beam, comprising: a main surface including a distal end portion and a proximal end portion, the distal end portion including a tip welding portion, a chamfered portion, and a lift tab; side rails extending from the main surface and the chamfered portion; and a slit disposed around the tip welding portion on the main surface. The tip welding portion is disposed on a chamfered portion forming line between the main surface and the chamfered portion.
2. The convex portion of the slit is on the distal side of the tip welding portion. The load beam according to claim 1.
3. The chamfered portion forming line is disposed so as to pass through the tip welding portion or through the proximal end portion of the tip welding portion. The load beam according to claim 1.
4. The chamfered portion forms an angle θ of 15 to 25°. The load beam according to claim 1.
5. The slit is semi-circular around the tip welding portion. The load beam according to claim 1.
6. The slit is U-shaped around the tip welding portion. The load beam according to claim 1.
7. The chamfered portion includes a proximal end portion and a distal end portion, the proximal end portion includes the chamfered portion forming line, and the distal end portion includes a lift tab. The load beam according to claim 1.
8. The lift tab is disposed more distally than the chamfered portion. The load beam according to claim 7.
9. The main surface includes dimples. The load beam according to claim 1.
10. The main surface includes a window. The load beam according to claim 1.
11. A suspension including a load beam, the load beam comprising: a main surface including a distal end portion and a proximal end portion, the distal end portion including a tip welding portion, a chamfered portion, and a lift tab; side rails extending from the main surface and the chamfered portion; and a slit disposed around the tip welding portion on the main surface. The tip welding portion is disposed on a chamfered portion forming line between the main surface and the chamfered portion.
12. The convex portion of the slit is on the distal side of the tip welding portion. The suspension according to claim 11.
13. The chamfered portion forming line is disposed so as to pass through the tip welding portion. The suspension according to claim 11.
14. The dust removal portion forms an angle θ of 15 to 25°, the suspension according to claim 11.
15. The slit is semi-circular around the tip welding portion, the suspension according to claim 11.
16. The slit is U-shaped around the tip welding portion, the suspension according to claim 11.
17. The dust removal portion includes a proximal end portion and a distal end portion, the proximal end portion includes the dust removal portion formation line, and the distal end portion includes a lift tab, the suspension according to claim 11.
18. The lift tab is disposed more distally than the dust removal portion, the suspension according to claim 17.
19. The main surface includes dimples, the suspension according to claim 11.
20. The main surface includes a window, the suspension according to claim 11.
21. A suspension, A load beam, the load beam including an attachment region at the proximal end of the load beam and a rigid region at the distal portion of the load beam, a load beam, A base plate attached to the attachment region of the load beam, A flexure attached to the rigid region of the load beam, comprising, The load beam is A main surface including a distal end portion and a proximal end portion, the distal end portion including a tip welding portion, a dust removal portion, and a lift tab, a main surface, A side rail extending from the main surface and the dust removal portion, A slit disposed around the tip welding portion on the main surface, further comprising, The tip welding portion is disposed on the dust removal portion formation line between the main surface and the dust removal portion, the suspension.