Interpose swage for hard disk drive

Abstract

To provide a head gimbal assembly (HGA) for hard disk drives.SOLUTION: A HGA includes a carriage arm 132 with a swage processing hole, two lead suspensions 110C, and two swage plates 200 to which the two suspensions are respectively coupled. Each swage plate includes a respective series of intermittent swage bosses 206 extending from a base plate, the swage bosses of each swage plate are respectively positioned relative to each other by extending to the swage processing hole 132a from each side of the carriage arm, and each of the one series of swage bosses interposes with the other series of swage bosses. By having both series of interposed swage bosses occupy the same swage hole height, the height of each swage boss can be effectively doubled, and a higher retention torque of the swage coupling is enabled even if it is considered in a thinner arm tip and shorter corresponding swage holes.SELECTED DRAWING: Figure 2B

Description

[Technical field]

[0001] FIELD OF THE DISCLOSURE Embodiments of the present invention may relate generally to hard disk drives and, more particularly, to an interpose swage boss approach. [Background technology]

[0002] A hard disk drive (HDD) is a non-volatile storage device that stores digitally encoded data on one or more circular disks that are housed in a protective enclosure and have magnetic surfaces. When an HDD is in operation, each magnetic recording disk is rapidly rotated by a spindle system. Data is read from and written to the magnetic recording disks using a read-write head (or "transducer") that is positioned over a specific location on the disk by an actuator. The read-write head uses a magnetic field to write data to and read data from the surface of the magnetic recording disk. The write head works by generating a magnetic field using an electric current that flows through the coil of the write head. Electrical pulses are sent to the write head with different patterns of positive and negative currents. The electric current in the coil of the write head creates a localized magnetic field across the gap between the head and the magnetic disk, which then magnetizes small areas on the recording medium.

[0003] HDDs include at least one head gimbal assembly (HGA) that typically includes a slider that houses a read / write transducer (or "read / write head") and a suspension. Each slider is attached to the free end of a suspension, which is then cantilevered from a rigid arm of an actuator. Several actuator arms can be combined to form a single movable unit, usually a head stack assembly (HSA) with a rotating pivot bearing system. A conventional HDD suspension typically includes a relatively rigid load beam with a mount plate at its base end, which is attached to an actuator arm, and whose free end carries a flexure that carries the slider and its read / write head. A compliant "hinge" is positioned between the mount plate and the functional end of the load beam in a vertical bending direction (perpendicular to the disk surface). The hinge allows the load beam to suspend and load the slider and read / write head toward the rotating disk surface. The function of the flexure is then to provide a gimbal support for the slider so that it can rock back and forth and side to side to adjust its orientation.

[0004] Any approach that may be described in this section is an approach that could be pursued, but not necessarily an approach that has been previously conceived or pursued, and thus, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section. [Brief description of the drawings]

[0005] Embodiments are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings in which like reference numbers refer to similar elements and in which: [Figure 1] 1 is a plan view showing a hard disk drive according to an embodiment. [Figure 2A] FIG. [Figure 2B]FIG. 2B is a side cross-sectional view showing a swaged suspension arm assembly utilizing the swage plate of FIG. 2A. [Diagram 3] FIG. 13 is an exploded perspective view showing a conventional swage boss. [Figure 4A] FIG. 1 illustrates an exploded perspective view of an exemplary interpose swage boss according to one embodiment. [Figure 4B] FIG. 13 is an exploded perspective view illustrating another exemplary interpose swage boss, according to one embodiment. [Diagram 5] FIG. 1 is a flow diagram illustrating a method for manufacturing a head gimbal assembly, according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0006] In general, a technique is described that enables a thin carriage arm tip by employing interposed swage bosses in a hard disk drive (HDD). In the following specification, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the invention described herein. However, it will be apparent that the embodiments of the invention described herein may be practiced without these specific details. In other instances, well-known structures and devices may be represented in block diagram form in order to avoid unnecessarily obscuring the embodiments of the invention described herein.

[0007] introduction term References herein to "an embodiment," "one embodiment," and the like are intended to mean that the particular feature, structure, or characteristic being described is included in at least one embodiment of the invention. However, instances of such phrases do not necessarily all refer to the same embodiment.

[0008] It will be understood that the term "substantially" describes features that are largely or approximately structured, configured, dimensioned, etc., however, that manufacturing tolerances and the like may result in situations where in practice the structure, configuration, dimensions, etc. are not always or necessarily precisely as described. For example, if one were to describe a structure as being "substantially vertical," the term would be assigned its obvious meaning such that the sidewalls are for all practical purposes vertical, but may not be at exactly 90 degrees.

[0009] Terms such as "optimal," "optimize," "minimal," "minimize," "maximum," "maximize," and the like may not have a specific value associated with them, but when such terms are used herein, it is intended that one of ordinary skill in the art will understand that such terms include affecting values, parameters, metrics, and the like in a beneficial direction consistent with the entirety of this disclosure. For example, describing some value as a "minimum" does not require that the value actually be equal to a theoretical minimum (e.g., zero), but should be understood in a practical sense in that the corresponding goal would be to move the value in a beneficial direction toward the theoretical minimum.

[0010] context Increasing the storage capacity of hard disk drives (HDDs) is one of the ongoing goals of HDD technology evolution. In one form, this goal manifests itself in increasing the number of disks implemented within a given HDD. However, customer demands often dictate maintaining a standard form factor as characterized in part by the z-height of the HDD. This inherently creates challenges with regard to fitting more disks into a given HDD, such as by requiring a dense mechanical structure in the z-height direction for the head gimbal assembly (HGA) that interposes between adjacent disks. More specifically, customer specifications and / or common design and operational constraints include operational shock (or "op-shock") requirements, which generally relate to the operational resistance or operational tolerance of the HDD to mechanical shock events. Recall that the suspension of an HDD typically includes a relatively rigid load beam having a mount plate at its base end, which is attached to an actuator arm, the free end of which carries a flexure that carries the slider and its read / write head. Thus, it remains a challenge to increase the number of disks while maintaining a standard form factor, thereby decreasing the distance between each disk in the disk stack, while at the same time ensuring that operational shock requirements are met. In particular, the limited mechanical clearances associated with HGAs, such as for operational positioning of each intervening suspension with the disks in the disk stack, pose a challenge to meeting such requirements. Stated another way, reduced disk-to-disk spacing may logically result in reduced operational shock performance in the context of a typically configured HGA.

[0011] FIG. 2A is a perspective view of a swage plate, and FIG. 2B is a side cross-sectional view of a swaged suspension arm assembly utilizing the swage plate of FIG. 2A. Swage plate 200 illustrates what may be considered a typical swage plate used to couple HDD suspensions to corresponding actuator arms. Swage plate 200 includes a body 202 that includes a swage through hole 204 therethrough, circumscribed by a swage boss 206. Typically, swage plate 200 has a suspension (such as lead suspension 110c of FIG. 1) welded or otherwise mechanically coupled (as well as electrically coupled) to it prior to swaging (or swaging coupling) of the suspension to a corresponding actuator arm (such as arm 132 or "carriage arm 132" of FIG. 1). Swaging is a well-known forging process, and is typically performed by forcing a swage ball 210 into the through hole 204 to deform or change the dimensions of the swage boss 206 (e.g., rotary swaging) and cold working the metal to form the bond or interconnection of the swage plate 200 / suspension 110c subcomponent and the actuator arm 132 subcomponent. That is, the swage boss 206 is inserted into the aperture 132a (or "swage hole 132a") of the actuator arm 132, and a swage ball 210, having a diameter larger than the inner diameter of the swage boss 206, is inserted into the swage through hole 204 of the swage boss 206 to swage the swage boss 206 into the aperture 132a by applying a compressive force to the inner surface of the swage boss 206, such that the swage boss 206 expands to hold the actuator arm 132 to the suspension 110c.

[0012] As can be seen from FIG. 2B, the distance (D) from the outer surface of the "up" suspension (e.g., upper suspension 110c housing an "up" (UP) head that interacts with the lower surface of a corresponding upper disk) and the "down" suspension (e.g., lower suspension 110c housing a "down" (DN) head that interacts with the upper surface of a corresponding lower disk) is a driving dimension related to the amount of dimensional clearance (C) provided between each suspension 110c and the corresponding disk surface on which the corresponding read / write transducer operates. This clearance C will therefore affect the likelihood that any of the HGA (or constituent subcomponents) will mechanically interact (e.g., "crash") with its corresponding disk surface as a result of a shock event, which in turn can affect the overall operational shock performance of the HDD. In view of the above and the goal of increasing the number of recording disks in a disk stack, an approach that reduces the distance D between a pair of suspensions swaged to a given actuator arm while maintaining the required clearance C with the corresponding disk surface may be desirable.

[0013] Approaches to the aforementioned space issues may include, for example, reducing the arm tip thickness within the constraints allowed by swage boss build-up, reducing the overall thickness of the stamped swage plate components (however, this may result in easy bending due to lower yield strength after annealing), and reducing the thickness of the media to allow for greater clearance between the media and the arm mounting surface.

[0014] Interposed swage bosses allow for thinner carriage arm tips As suggested, currently, the common approach for HGA assembly involves swaging, whereby both UP / DN heads are swaged in the same hole in the carriage arm (or "actuator arm" or simply "arm"), except for the end arm and corresponding head. However, with the move to increase storage capacity of HDDs by incorporating more disks, the thickness of the arm tip tends to become thinner, and therefore the height of the swage boss tends to become lower. This will likely result in a lower holding torque of the swage joint, and also creates manufacturing difficulties.

[0015] 3 is an exploded perspective view showing a conventional swage boss. Each swage plate 300 includes a base plate 302 and a swage boss 304 extending from the base plate 302 around a through hole 305. When assembled, the swage boss 304 of the lower swage plate 300 (for a DN head) extends upward into a corresponding swage hole (see, e.g., swage hole 132a in FIG. 2B) of the arm 132 (see, e.g., arm 132 in FIG. 1, FIG. 2B), while the swage boss 304 of the upper swage plate 300 (for a UP head) extends downward into a corresponding swage hole 132a in the arm 132. The trend toward shorter swage bosses 304 arises because of the trend toward thinner arm 132 tips, i.e., the portions that contain the swage holes 132a where the corresponding suspensions (see, e.g., lead suspensions 110c in FIGS. 1 and 2B) are swaged to the arm 132 via the swage plate 300. That is, because each swage boss 304 occupies a portion of the height of the swage hole 132a, the height h of each swage boss 304 is limited by the thickness of the arm 132 tip and thus the equivalent height of the swage hole 132a in the arm 132 (e.g., approximately twice the height 2h).

[0016] 4A is an exploded perspective view showing an exemplary interposed swage boss, according to one embodiment. The first swage plate 410a (for a UP head) of this embodiment comprises a base plate 412 and a first series of interrupted swage boss structures 414a, 414b, 414c, e.g., extending from the base plate 412 around a through hole 415 and separated by slots. Similarly, the second swage plate 410b (for a DN head) of this embodiment comprises a base plate 412 and a second series of interrupted swage boss structures 414d, 414e, 414f, e.g., extending from the base plate 412 around a through hole 415 and separated by slots. It should be noted that the number of swage boss structures (e.g., 412a-412c and 412d-412f) corresponding to each respective first and second series of intermittent swage boss structures on each swage plate 412a, 412b may vary from implementation to implementation, with three of each shown here (412a-412c for 410a, and 412d-412f for 410b) for illustrative purposes.

[0017] When assembled, each of the first series of intermittent swage boss structures 414a, 414b, 414c of the upper swage plate 410a extends downwardly from a first side of the carriage arm 132 (e.g., see arm 132 in Figures 1 and 2B) into a corresponding swage hole in the carriage arm 132 (e.g., see swage hole 132a in Figure 2B), and each of the second series of intermittent swage boss structures 414d, 414e, 414f of the lower swage plate 410b (for the DN head) extends upwardly from a second side of the carriage arm 132 into a corresponding swage hole 132a. According to one embodiment, each intermittent swage boss structure of the first series 414a, 414b, 414c is positioned between adjacent intermittent swage boss structures of the second series 414d, 414e, 414f, i.e., within a corresponding slot of the other series. The respective swage boss structures of swage plate 410a and swage plate 410b are considered "interlocked" because the respective swage boss structures are clocked, interlockingly keyed, and interposed with one another. Thus, the first swage plate 410a couples a first suspension assembly (e.g., see lead suspension 110c in FIG. 1) to a first side of the carriage arm 132 via a first series of intermittent swage boss structures 414a, 414b, 414c extending in one direction within the swaged hole 132a of the carriage arm 132, and the second swage plate 410b couples a second suspension assembly (e.g., see lead suspension 110c in FIG. 1) to a second, opposite side of the carriage arm 132 via a second series of intermittent swage boss structures 414d, 414e, 414f extending in the opposite direction within the swaged hole 132a of the carriage arm 132, such that the respective first and second series of intermittent swage boss structures 414a-414c, 414d-414f do not interfere with each other.

[0018] Here, because both the first and second series of interleaved intermittent swage boss structures 414a-414c, 414d-414f effectively occupy the same height of swage hole 132a, the height H1 of each swage boss 414a-414f can effectively be about twice the height h of FIG. 3, e.g., H1=about 2h. Thus, compared to the configuration of swage plate 300 of FIG. 3, a higher holding torque of the swage connection is possible, even considering the thinner arm tips and corresponding shorter swage holes. The height h of swage boss 304 of swage plate 300 of FIG. 3 and the height H of each swage boss 414a-414f of FIG. 4A are approximately 2 times the height h of swage boss 304 of swage plate 300 of FIG. 3 and approximately 2 times the height H of swage boss 414a-414f of FIG. l It should be noted that the diagrams are not intended to be drawn to scale, but are drawn to depict a general sense of doubling in height / size. According to one embodiment, the height of the swage boss structures of the first series of intermittent swage boss structures 414a-414c that extend in one direction into the swage hole 132a of the carriage arm 132 is substantially equal to the height of the swage boss structures of the second series of intermittent swage boss structures 414d-414f that extend in the opposite direction into the swage hole 132a of the arm 132.

[0019] Other variations are contemplated. According to one embodiment, the swage boss structures of the first series of intermittent swage boss structures 414a-414c and the swage boss structures of the second series of intermittent swage boss structures 414d-414f are equidistant, and according to an alternative embodiment, the swage boss structures of the first series of intermittent swage boss structures 414a-414c, 414d-414f are not equidistant. Further, according to one embodiment, each of the swage boss structures in the first series of intermittent swage boss structures 414a-414c and / or each of the swage boss structures in the second series of intermittent swage boss structures 414d-414f have substantially equal circumferential spans, while according to alternative embodiments, each of the swage boss structures in the first series of intermittent swage boss structures 414a-414c and / or each of the swage boss structures in the second series of intermittent swage boss structures 414d-414f have substantially unequal circumferential spans. Thus, swage plates 410a, 410b may be optimized for a particular design scenario based, for example, on mechanical configurations and constraints, loads, design goals, etc.

[0020] As noted above, the number of swage boss structures (e.g., 412a-412c and 412d-412f) corresponding to each respective first and second series of intermittent swage boss structures of each swage plate 412a, 412b may vary from implementation to implementation based on, for example, mechanical configuration and constraints, loads, design goals, etc. FIG. 4B is an exploded perspective view showing another exemplary interposed swage boss according to one embodiment. The first swage plate 420a (for the UP head) of this embodiment comprises a base plate 422 and a first series of intermittent swage boss structures 424a-1-424a-n separated by slots, where n represents any number of intermittent swage boss structures (here eight) that may vary from implementation to implementation, extending from the base plate 422 around the through hole 425. Similarly, the second swage plate 420b (for a DN head) of this embodiment comprises a base plate 422 and a second series of intermittent swage boss structures 424b-1 to 424b-n separated by slots extending from the base plate 422 around a through hole 425.

[0021] When assembled, each of the first series of intermittent swage boss structures 424a-1 to 424a-n of the upper swage plate 420a extends downwardly from a first side of the carriage arm 132 (e.g., see arm 132 in Figures 1 and 2B) into a corresponding swage hole (e.g., see swage hole 132a in Figure 2B) of the carriage arm 132, while each of the second series of intermittent swage boss structures 424b-1 to 424b-n of the lower swage plate 420b (for DN head) extends upwardly from a second side of the carriage arm 132 into a corresponding swage hole 132a. According to one embodiment, again, each intermittent swage boss structure of the first series 424a-1 through 424a-n is positioned between adjacent intermittent swage boss structures of the second series 424b-1 through 424b-n, i.e., within a corresponding slot of the other series. The swage boss structures of swage plate 420a and swage plate 420b are considered to be interposed or "interlocked." Thus, the first swage plate 420a couples a first suspension assembly (e.g., see lead suspension 110c in FIG. 1 ) to a first side of the carriage arm 132 via a first series of intermittent swage boss structures 424a-1 to 424a-n that extend in one direction within the swaged hole 132a of the carriage arm 132, and the second swage plate 420b couples a second suspension assembly (e.g., see lead suspension 110c in FIG. 1 ) to a second, opposite side of the carriage arm 132 via a second series of intermittent swage boss structures 424b-1 to 424b-n that extend in the opposite direction within the swaged hole 132a of the carriage arm 132, such that the respective first and second series of intermittent swage boss structures 424a-1 to 424a-n and 424b-1 to 424b-n do not interfere with each other.

[0022] Again, because both the first and second series of interleaved intermittent swage boss structures 424a-1-424a-n, 424b-1-424b-n effectively occupy the same height of swage hole 132a, the height H2 of each swage boss 424a-1-424b-n can be effectively approximately doubled from the height h of FIG. 3, e.g., H2=approximately 2h. Thus, a higher holding torque of the swage connection is possible, even considering the thinner arm tips and shorter corresponding swage holes, as compared to the configuration of swage plate 300 of FIG. 3. It should be noted that the height h of swage boss 304 of swage plate 300 of FIG. 3 and the height H2 of each swage boss 424a-1-424b-n of FIG. 4B are not intended to be drawn to scale, but are drawn to depict the general sense of doubling in height / size. According to one embodiment, the height of the swage boss structures of a first series of intermittent swage boss structures 424a-1 to 424a-n extending in one direction within the swage hole 132a of the carriage arm 132 is substantially equal to the height of the swage boss structures of a second series of intermittent swage boss structures 424b-1 to 424b-n extending in the opposite direction within the swage hole 132a of the arm 132.

[0023] Similar to the exemplary embodiment of FIG. 4A, and referring again to FIG. 4B, according to one embodiment, the swage boss structures of the first series of intermittent swage boss structures 424a-1 to 424b-n and the swage boss structures of the second series of intermittent swage boss structures 424b-1 to 424b-n are equidistant, and according to an alternative embodiment, the swage boss structures of the first series of intermittent swage boss structures 424a-1 to 424b-n, 424b-1 to 424b-n are not equidistant. Further, according to one embodiment, each of the swage boss structures of the first series of intermittent swage boss structures 424a-1-424b-n and / or each of the swage boss structures of the second series of intermittent swage boss structures 424b-1-424b-n have substantially equal circumferential spans, and according to alternative embodiments, each of the swage boss structures of the first series of intermittent swage boss structures 424a-1-424b-n and / or each of the swage boss structures of the second series of intermittent swage boss structures 424b-1-424b-n have substantially unequal circumferential spans. Thus, swage plates 420a, 420b may also be optimized for a particular design scenario based, for example, on mechanical configurations and constraints, loads, design goals, etc.

[0024] How to assemble the head gimbal assembly 5 is a flow diagram illustrating a method of manufacturing a head gimbal assembly, according to one embodiment. A head gimbal assembly (HGA) assembled, manufactured, or produced according to the method of FIG. 5 is designed, configured, and intended for incorporation into a hard disk drive (HDD) (see, e.g., FIG. 1).

[0025] At block 502, a first suspension is swaged to a first side of the actuator arm via a first interpose swage boss of a first swage plate, the first interpose swage boss comprising a first intermittent group of extending swage boss structures extending around a through hole in the first swage plate. For example, a first suspension (see, e.g., lead suspension 110c in FIG. 1) is swaged to a first side of an actuator arm (see, e.g., arm 132 in FIG. 1) via a first interposed swage boss of a first swage plate 410a (FIG. 4A), 420a (FIG. 4B), which includes a first interposed group of extended swage boss structures 414a, 414b, 414c (FIG. 4A), 424a-1 through 424a-n (FIG. 4B) that extend around a through hole 415 (FIG. 4A), 425 (FIG. 4B) of the first swage plate 410a, 420a. According to one embodiment, the first suspension 110a is swaged to a first side of the actuator arm 132 such that each extended swage boss structure 414a, 414b, 414c, 424a-1 to 424a-n of the first intermittent group 424a-414c, 424a-1 to 414a-n is positioned between adjacent extended swage boss structures of the second intermittent group 414d-414f (FIG. 4A), 424b-1 to 424b-n (FIG. 4B).

[0026] At block 504, a second suspension is swaged to an opposing second side of the actuator arm via a second interpose swage boss of a second swage plate, the second interpose swage boss comprising a second intermittent group of extending swage boss structures extending around a through hole in the second swage plate. For example, a second suspension (see, e.g., lead suspension 110c in FIG. 1) is swaged to an opposing second side of actuator arm 132 via a second interposed swage boss of second swage plate 410b (FIG. 4A), 420b (FIG. 4B), which includes a second interposed group of extended swage boss structures 414d, 414e, 414f (FIG. 4A), 424b-1 through 424b-n (FIG. 4B) that extend around through holes 415 (FIG. 4A), 425 (FIG. 4B) of second swage plates 410b, 420b. Similarly, according to one embodiment, the second suspension 110a is swaged to the second side of the actuator arm 132 such that each extended swage boss structure 414d, 414e, 414f, 424b-1 to 424b-n of the second intermittent group 414d-414f, 424b-1 to 424b-n is positioned between adjacent extended swage boss structures of the first intermittent group 414a-414c, 424a-1 to 424a-n.

[0027] As a result of performing blocks 502-504, swaging the first suspension (block 502) includes swaging a first intermittent group of extending swage boss structures 414a-414c, 424a-1-424a-n extending in one direction (e.g., downward) from a first side (e.g., an upper side) of the actuator arm 132 into a swage hole 132a (see, e.g., FIG. 2B ) of the actuator arm 132, and swaging a second suspension (block 504). 4) includes swaging a second intermittent group of extending swage boss structures 414d-414f, 424b-1-424b-n extending in an opposite direction (e.g., upward) from a second side (e.g., underneath) into the swage hole 132a of the actuator arm 132 such that the second intermittent group 414d-414f, 424b-1-424b-n does not substantially interfere (e.g., mechanically, structurally) with the first intermittent group 414a-414c, 424a-1-424a-n. This is not to say that after swaging, there is absolutely no contact between any of the first intermittent swage boss structures 414a-, 414b, 414c, 424a-1 through 424a-n and the second intermittent swage boss structures 414d, 414e, 414f, 424b-1 through 424b-n, whereby such structures are cold worked to form an interconnection of the components. Rather, there may be some contact after swaging, but such contact is not expected to interfere with the intended purpose of producing a viable swage joint or joint. Thus, a higher holding torque of the swage joint is expected, even considering the thinner arm tips and shorter corresponding swage holes, as compared to the configuration of the swage plate 300 of FIG. 3.

[0028] Illustrative physical description of the operating context The embodiments may be used in the context of a digital data storage device (DSD), such as a hard disk drive (HDD). Thus, according to an embodiment, a plan view showing a conventional HDD 100 is shown in FIG. 1 to help describe how a conventional HDD typically operates.

[0029] FIG. 1 shows a functional arrangement of components of a HDD 100, including a slider 110b that includes a magnetic read-write head 110a. Collectively, the slider 110b and the head 110a may be referred to as a head slider. The HDD 100 includes at least one head gimbal assembly (HGA) 110 that includes the head slider, a lead suspension 110c that is typically attached to the head slider via a flexure, and a load beam 110d that is attached to the lead suspension 110c. The HDD 100 also includes at least one recording medium 120 that is rotatably mounted on a spindle 124, and a drive motor (not visible) that is attached to the spindle 124 to rotate the medium 120. The read-write head 110a, which may also be referred to as a transducer, includes a write element and a read element for writing and reading information stored on the medium 120 of the HDD 100, respectively. The medium 120 or multiple disk media may be secured to a spindle 124 with a disk clamp 128 .

[0030] The HDD 100 further includes an arm 132 mounted to the HGA 110, a carriage 134, and a voice coil motor (VCM) including an armature 136 including a voice coil 140 mounted to the carriage 134, and a stator 144 including a voice coil magnet (not shown). The VCM armature 136 is attached to the carriage 134 and is configured to move the arm 132 and HGA 110 to access portions of the media 120, all collectively mounted on a pivot shaft 148 with an intervening pivot bearing assembly 152. In a HDD with multiple disks, the carriage 134 may be referred to as an "E-block" or comb because the carriage is arranged to carry an array of interlocking arms that give the carriage the appearance of a comb.

[0031] An assembly comprising a head gimbal assembly (e.g., HGA 110), including a flexure to which a head slider is coupled, an actuator arm (e.g., arm 132) and / or a load beam to which the flexure is coupled, and an actuator (e.g., VCM) to which the actuator arm is coupled, may be collectively referred to as a head stack assembly (HSA). However, an HSA may include more or less components than those listed. For example, an HSA may refer to an assembly that further includes electrical interconnect components. In general, an HSA is an assembly configured to move a head slider to access portions of the medium 120 for read and write operations.

[0032] With further reference to FIG. 1 , electrical signals including write signals to and read signals from head 110a (e.g., current to the voice coil 140 of the VCM) are transmitted by a flexible cable assembly (FCA) 156 (or “flex cable,” or “flexible printed circuit” (FPC)). The interconnect between flex cable 156 and head 110a may include an arm-electronics (AE) module 160, which may have on-board preamplifiers for the read signal, as well as other read channel and write channel electronics. The AE module 160 may be mounted to the carriage 134 as shown. The flex cable 156 may be coupled to an electrical connector block 164, which in some configurations provides electrical communication through an electrical feedthrough provided by an HDD enclosure 168. The HDD housing 168 (or “enclosure base”, or “base plate” or simply “base”), together with the HDD cover, provides a semi-sealed (or, in some configurations, hermetically sealed) protective enclosure for the information storage components of the HDD 100.

[0033] A disk controller including a digital-signal processor (DSP) and other electronic components including servo electronics provide electrical signals to the drive motor, the voice coil 140 of the VCM, and the head 110a of the HGA 110. The electrical signals provided to the drive motor enable the drive motor to rotate providing a torque to the spindle 124, which is then transferred to the medium 120 attached to the spindle 124. As a result, the medium 120 rotates in a direction 172. The rotating medium 120 forms a cushion of air that acts as an air bearing on which the air-bearing surface (ABS) of the slider 110b rides so that the slider 110b flies above the surface of the medium 120 without contacting the thin magnetic recording layer on which the information is recorded. Similarly, in HDDs where a lighter-than-air gas such as helium is utilized as a non-limiting example, the rotating medium 120 creates a cushion of gas that acts as a gas or fluid bearing on which the slider 110b rides.

[0034] An electrical signal provided to the voice coil 140 of the VCM enables the head 110a of the HGA 110 to access the track 176 on which information is to be recorded. Thus, the armature 136 of the VCM swings through an arc 180 to enable the head 110a of the HGA 110 to access various tracks on the medium 120. Information is stored on the medium 120 in a number of radially nested tracks arranged in sectors on the medium 120, such as sector 184. Correspondingly, each track is made up of a number of sectorized track portions (or "track sectors"), such as sectorized track portion 188. Each sectorized track portion 188 may include the recorded information and a header that includes error correction code information and a servo burst signal pattern, such as an ABCD servo burst signal pattern, which is information identifying the track 176. When accessing track 176, a read element of head 110a of HGA 110 reads a servo burst signal pattern that provides a position-error-signal (PES) to the servo electronics, which enables head 110a to follow track 176 by controlling an electrical signal provided to the voice coil 140 of the VCM. Upon locating track 176 and identifying a particular sectored track portion 188, head 110a reads information from track 176 or writes information to track 176 in response to instructions received by a disk controller from an external agent, e.g., a microprocessor of a computer system.

[0035] The electronic architecture of an HDD includes numerous electronic components, such as a hard disk controller ("HDC"), an interface controller, an arm electronics module, a data channel, a motor driver, a servo processor, a buffer memory, etc., each performing its respective function for the operation of the HDD. Two or more of such components may be combined on a single integrated circuit board, referred to as a "system on a chip" ("SOC"). Some, but not all, of such electronic components are typically located on a printed circuit board that is coupled to the bottom side of the HDD, such as in the HDD housing 168.

[0036] References herein to hard disk drives, such as HDD 100 shown and described with reference to FIG. 1, may encompass information storage devices that may be referred to as "hybrid drives." A hybrid drive generally refers to a storage device that has the functionality of both a traditional HDD (see, e.g., HDD 100) combined with a solid-state storage device (SSD) that uses non-volatile memory such as electrically erasable and programmable flash or other solid-state (e.g., integrated circuit) memory. Because the operation, management, and control of different types of storage media are typically different, the solid-state portion of the hybrid drive may include its own corresponding controller functionality, or the controller functionality may be integrated into a single controller along with the HDD functionality. A hybrid drive may be designed and configured to operate and utilize the solid-state portion in several ways, such as by using the solid-state memory as a cache memory, as a non-limiting example, to store frequently accessed data, to store I / O intensive data, and the like. Additionally, a hybrid drive may be designed and configured essentially as two storage devices in a single enclosure, i.e., a traditional HDD and an SSD, with either one or multiple interfaces for host connection.

[0037] Augmentations and Alternatives In the foregoing description, the embodiments of the invention have been described with reference to numerous specific details that may vary from implementation to implementation. Accordingly, various modifications and changes may be made without departing from the broader spirit and scope of the embodiments. Thus, the sole and exclusive reference of what is, and what the applicants intend to be, the invention is the set of claims originating from this application, in the particular form in which such claims originate, including any subsequent amendments. The definitions expressly set forth herein for the terms contained in such claims shall govern the meaning of the terms as used in the claims. Hence, any limitations, elements, characteristics, features, advantages or attributes not expressly recited in the claims should in no way limit the scope of such claims. Hereby, the specification and drawings are to be regarded in an illustrative and not restrictive sense.

[0038] Additionally, certain process steps may be described herein in a particular order, and alphabetic and alphanumeric symbols may be used to identify particular steps. Unless otherwise specified herein, embodiments are not necessarily limited to any particular order of performing such steps. In particular, symbols are used merely for convenient identification of steps, and are not intended to specify or require a particular order of performing such steps.

Claims

1. A head gimbal assembly (HGA), comprising: an arm having a swaged hole; a first suspension assembly; a first swage plate to which the first suspension assembly is coupled, the first swage plate coupling the first suspension assembly to a first side of the arm and comprising a first series of intermittent swage boss formations extending from a first base plate around a through hole in the first base plate; a second suspension assembly; a second swage plate to which the second suspension assembly is coupled, the second swage plate coupling the second suspension assembly to a second opposing side of the arm and comprising a second series of intermittent swage boss formations extending from a second base plate around a through hole in the second base plate; A head gimbal assembly (HGA), wherein each intermittent swage boss structure of the first series of intermittent swage boss structures is positioned between adjacent intermittent swage boss structures of the second series of intermittent swage boss structures.

2. the first swage plate couples the first suspension assembly to the first side of the arm via the first series of intermittent swage boss structures extending unidirectionally into the swage holes of the arm; 2. The HGA of claim 1, wherein the second swage plate couples the second suspension assembly to the second side of the arm via the second series of intermittent swage boss structures that extend in opposite directions into the swage holes of the arm, such that the second series of intermittent swage boss structures do not interfere with the first series of intermittent swage boss structures.

3. 2. The HGA of claim 1, wherein a height of the swage boss structure of the first series of intermittent swage boss structures extending in one direction into the swage hole of the arm is substantially equal to a height of the swage boss structure of the second series of intermittent swage boss structures extending in an opposite direction into the swage hole of the arm.

4. 2. The HGA of claim 1, wherein said swage boss structures of said first series of intermittent swage boss structures are equidistant.

5. 2. The HGA of claim 1, wherein said swage boss structures of said first series of intermittent swage boss structures are not equidistant.

6. The HGA of claim 1 , wherein each of said swage boss structures in said first series of intermittent swage boss structures has a substantially equal circumferential span.

7. The HGA of claim 1 , wherein at least two of said swage boss structures of said first series of intermittent swage boss structures have unequal circumferential spans.

8. A hard disk drive comprising the HGA of claim 1.

9. A hard disk drive (HDD), A plurality of recording disk media rotatably mounted on a spindle; means for writing to and reading from a first one of the plurality of recording disk media; a voice coil actuator configured to move the means for writing and reading to access portions of the first recording disk medium; a head gimbal assembly (HGA) coupled to the voice coil actuator, the HGA comprising: a carriage arm having a swaged hole; a first suspension assembly including a load beam and a flexure; a first swage plate to which the first suspension assembly is coupled, the first swage plate coupling the first suspension assembly to a first side of the carriage arm and comprising a first series of intermittent swage boss formations extending from a first base plate around through holes in the first base plate; a second suspension assembly including a load beam and a flexure; a second swage plate to which the second suspension assembly is coupled, the second swage plate coupling the second suspension assembly to a second side of the carriage arm and comprising a second series of intermittent swage boss formations extending from a second base plate around through holes in the second base plate; each intermittent swage boss structure of the first series of intermittent swage boss structures is positioned between an adjacent intermittent swage boss structure of the second series of intermittent swage boss structures.

10. the first swage plate of the HGA couples the first suspension assembly to the first side of the carriage arm via the first series of intermittent swage boss structures extending unidirectionally into the swage holes of the carriage arm; 10. The HDD of claim 9, wherein the second swage plate of the HGA couples the second suspension assembly to the second side of the carriage arm via the second series of intermittent swage boss structures that extend in opposite directions into the swage holes of the carriage arm, such that the second series of intermittent swage boss structures do not interfere with the first series of intermittent swage boss structures.

11. 10. The HDD of claim 9, wherein a height of the swage boss structure of the first series of intermittent swage boss structures extending in one direction into the swage hole of the carriage arm is substantially equal to a height of the swage boss structure of the second series of intermittent swage boss structures extending in an opposite direction into the swage hole of the carriage arm.

12. 10. The HDD of claim 9, wherein the swage boss structures of the first series of intermittent swage boss structures of the HGA are equidistant.

13. 10. The HDD of claim 9, wherein the swage boss structures of the first series of intermittent swage boss structures of the HGA are not equidistant.

14. 1. A method for assembling a head gimbal assembly (HGA), comprising: swaging a first suspension to a first side of an actuator arm via a first interpose swage boss of a first swage plate, the first interpose swage boss comprising a first intermittent group of extending swage boss structures extending around a through hole in the first swage plate; swaging a second suspension to an opposing second side of the actuator arm via a second interpose swage boss of a second swage plate, the second interpose swage boss comprising a second intermittent group of extending swage boss structures extending around a through hole in the second swage plate.

15. 15. The method of claim 14, wherein swaging the first suspension includes swaging through the first interposing swage bosses such that each extended swage boss structure of the first intermittent group is positioned between adjacent extended swage boss structures of the second intermittent group.

16. 16. The method of claim 15, wherein swaging the second suspension includes swaging through the second interposing swage bosses such that each extended swage boss structure of the second intermittent group is positioned between adjacent extended swage boss structures of the first intermittent group.

17. swaging the first suspension includes swaging the first intermittent group of extending swage boss structures extending in one direction from the first side into swage holes in the actuator arm; 17. The method of claim 16, wherein swaging the second suspension includes swaging the second intermittent group of extending swage boss structures extending in an opposite direction from the second side into the swage hole of the actuator arm such that the second intermittent group does not interfere with the first intermittent group.

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