Interpose Space 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] Embodiments of the present invention generally relate to hard disk drives and, in particular, may relate to the technique of interposing servo bosses.

Background Art

[0002] A hard disk drive (HDD) is a non-volatile memory device that stores digitally encoded data on one or more circular disks having a magnetic surface, housed within a protective enclosure. When the HDD is operating, each magnetic recording disk is rapidly rotated by a spindle system. Data is read from and written to the magnetic recording disk using a read-write head (or "transducer") 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 functions by generating a magnetic field using an electric current flowing through a coil of the write head. Electric pulses are sent to the write head with different patterns of positive and negative currents. The current in the coil of the write head generates a local magnetic field across the gap between the head and the magnetic disk, which then magnetizes a small area on the recording medium.

[0003] An HDD generally includes at least one head gimbal assembly (HGA) that houses a read / write transducer (or "read / write head") and a suspension. Each slider is attached to the free end of the suspension, and then the suspension is cantilevered from the rigid arm of an actuator. Several actuator arms can be combined to form a single movable unit, typically a head stack assembly (HSA) having a rotary pivot bearing system. The suspension of a conventional HDD typically includes a relatively rigid load beam having a mount plate at its base end, the mount plate being attached to the actuator arm, and its free end carrying a flexure that supports 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 towards the rotating disk surface. Next, the function of the flexure is to provide gimbal support to the slider so that the slider can rock back and forth and side to side to adjust its orientation.

[0004] Any technique that may be described in this section is a technique that may be pursued, but not necessarily a technique that has been previously devised or pursued. Thus, unless otherwise indicated, none of the techniques described in this section should be assumed to be eligible as prior art merely by virtue of their inclusion in this section.

Brief Description of the Drawings

[0005] Embodiments are shown by way of example and not limitation in the figures of the accompanying drawings, in which like reference numerals refer to similar elements.

Figure 1

Figure 2A

Figure 2B

Figure 3

Figure 4A

Figure 4B

Figure 5

[0006] In general, a technique that enables a thin carriage arm tip by employing an interpose swage boss in a hard disk drive (HDD) is described. In the following specification, for the purpose 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 Terms References herein to "embodiment", "one embodiment", etc. are intended to mean that a particular feature, structure, or characteristic described is included in at least one embodiment of the invention. However, such instances are not necessarily all directed to the same embodiment.

[0008] The term "substantially" will be understood to describe features that are mostly or nearly structured, configured, dimensioned, etc., but manufacturing tolerances and the like can result in situations where the structure, configuration, dimensions, etc. are not always or necessarily precisely described. For example, if a structure is described as "substantially vertical", the term is assigned its plain meaning such that the side walls are vertical for all practical purposes, but may not be exactly 90 degrees.

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

[0010] Context Increasing the storage capacity of a hard disk drive (HDD) is one of the ongoing goals of HDD technology evolution. In one form, this goal manifests as increasing the number of disks implemented within a given HDD. However, in many cases, customer requirements call for maintaining a standard form factor that is partially characterized by the height of the HDD. This poses an inherent challenge in fitting more disks into a given HDD, such as by requiring a high-density mechanical structure in the height direction for the head gimbal assembly (HGA) intervening between adjacent disks. More specifically, customer specifications and / or common designs and operating constraints include an operating shock (or "op-shock") requirement, which is generally related to the operating resistance or tolerance of the HDD to mechanical shock events. The suspension of an HDD typically includes a relatively rigid load beam having a mount plate at its base end, the mount plate being attached to the actuator arm, and it is to be recalled that its free end carries a flexure that supports 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 reducing the distance between each disk in the disk stack and at the same time reliably meeting the operating shock requirement. In particular, the limited mechanical clearance associated with the HGA, such as for the operating positioning of each suspension intervening with the disks within the disk stack, poses a challenge for meeting such requirements. Put another way, as the spacing between disks decreases, logically, in the context of a typically configured HGA, the operating shock performance can degrade.

[0011] FIG. 2A is a perspective view showing a swage plate, and FIG. 2B is a side cross-sectional view showing a swaged suspension arm assembly using the swage plate of FIG. 2A. The swage plate 200 is shown as being a typical swage plate used to couple an HDD suspension to a corresponding actuator arm. The swage plate 200 includes a body 202 that includes a through swage through-hole 204 surrounded by a swage boss 206. Typically, the swage plate 200 has a suspension (such as the lead suspension 110c of FIG. 1) that is welded or otherwise mechanically coupled (and electrically coupled) prior to swaging (or swage coupling) 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 that typically involves pushing a swage ball 210 into the through-hole 204 to deform or change the dimensions of the swage boss 206 (e.g., rotary swaging), cold working the metal to form a connection or interconnection between the swage plate 200 / suspension 110c sub-components and the actuator arm 132 sub-components. That is, the swage boss 206 is inserted into an 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 apply a compressive force to the inner surface of the swage boss 206 to swage-couple the swage boss 206 to the aperture 132a, causing the swage boss 206 to expand to hold the actuator arm 132 to the suspension 110c.

[0012] As can be seen from FIG. 2B, the distance (D) from the outer surfaces of the "up" suspension (e.g., the upper suspension 110c that houses the "up" (UP) head that interacts with the lower surface of the corresponding upper disk) and the "down" suspension (e.g., the lower suspension 110c that houses the "down" (DN) head that interacts with the upper surface of the corresponding lower disk) is a drive 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. Thus, this clearance C will affect the likelihood that either the HGA (or a component sub-component) mechanically interacts (e.g., "collides") with its corresponding disk surface as a result of an impact event, which can similarly affect the overall operating shock performance of the HDD. Considering the above and the goal of increasing the number of recording disks within the disk stack, a technique for reducing the distance D between a pair of suspensions swaged onto a given actuator arm while maintaining the necessary clearance C with the corresponding disk surface may be desirable.

[0013] The aforementioned techniques for the space problem can include, for example, reducing the arm tip thickness within the constraints allowed by swage boss buildup, reducing the total thickness of the stamped swage plate part (however, this can result in easy bending due to the lower yield strength after annealing), and reducing the thickness of the medium to allow for a greater clearance between the medium and the arm mounting surface.

[0014] Interpose swage boss enabling a thinner carriage arm tip As suggested, the current general approach for HGA assembly involves swaging, by which both UP / DN heads are swaged in the same holes of the carriage arm (or "actuator arm" or simply "arm"), excluding the end arms and corresponding heads. However, with the movement to increase the storage capacity of HDDs by incorporating more disks, the thickness of the arm tip tends to become thinner, and thus the height of the swage boss tends to become lower. This is likely to result in a lower holding torque for the swage joint and also poses difficulties in manufacturing.

[0015] Figure 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 the DN head) extends upwardly into a corresponding swage hole (see, for example, swage hole 132a in FIGS. 1 and 2B) of the arm 132 (see, for example, arm 132 in FIGS. 1 and 2B), while the swage boss 304 of the upper swage plate 300 (for the UP head) extends downwardly into the corresponding swage hole 132a of the arm 132. Due to the tendency of the thinner arm 132 tip, i.e., the corresponding suspension (see, for example, lead suspension 110c in FIGS. 1 and 2B) to be swaged to the arm 132 through the swage plate 300 towards the portion including the swage hole 132a, there is a tendency towards a shorter swage boss 304. That is, since each swage boss 304 occupies a part 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 of the arm 132 (for example, approximately twice the height 2h).

[0016] Figure 4A is an exploded perspective view showing an exemplary interpose swage boss according to one embodiment. The first swage plate 410a (for the UP head) of this embodiment includes a base plate 412 and, for example, a first series of intermittent swage boss structures 414a, 414b, 414c that extend around the through-hole 415 from the base plate 412 and are separated by slots. Similarly, the second swage plate 410b (for the DN head) of this embodiment includes a base plate 412 and, for example, a second series of intermittent swage boss structures 414d, 414e, 414f that extend around the through-hole 415 from the base plate 412 and are separated by slots. The number of swage boss structures (for example, 412a to 412c and 412d to 412f) corresponding to the first and second series of intermittent swage boss structures of each of the respective first and second swage plates 412a, 412b can vary for each implementation, and here, for illustrative purposes, three each (412a to 412c for 410a and 412d to 412f for 410b) are shown.

[0017] When assembled, each of the first series of intermittent swage boss structures 414a, 414b, 414c of the upper swage plate 410a extends downward into the corresponding swage hole (see, e.g., swage hole 132a in FIGS. 1 and 2B) of the carriage arm 132 (see, e.g., arm 132 in FIGS. 1 and 2B) from the first side of the carriage arm 132, 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 upward into the corresponding swage hole 132a from the second side of the carriage arm 132. According to one embodiment, each intermittent swage boss structure of the first series of intermittent swage boss structures 414a, 414b, 414c is positioned between adjacent intermittent swage boss structures of the second series of intermittent swage boss structures 414d, 414e, 414f, i.e., within the other series of corresponding slots. The respective swage boss structures of the swage plate 410a and the swage plate 410b are keyed so that the respective swage boss structures are clocked and interlock, and are interposed between each other, and thus are considered to be "interlocked". Accordingly, the first swage plate 410a couples the first suspension assembly (see, e.g., lead suspension 110c in FIG. 1) to the first side of the carriage arm 132 via the first series of intermittent swage boss structures 414a, 414b, 414c that extend in one direction within the swage hole 132a of the carriage arm 132, and the second swage plate 410b couples the second suspension assembly (see, e.g., lead suspension 110c in FIG. 1) to the second opposite side of the carriage arm 132 via the second series of intermittent swage boss structures 414d, 414e, 414f that extend in the opposite direction within the swage 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, since both the first and second series of intervening intermittent swage boss structures 414a - 414c, 414d - 414f effectively occupy the same height of the swage hole 132a, the height H of each swage boss 414a - 414f 1 is effectively approximately twice the height h in FIG. 3, for example, H 1 = can be approximately 2h. Thus, even considering the thinner arm tip and the shorter corresponding swage hole compared to the configuration of the swage plate 300 in FIG. 3, a higher holding torque for the swage joint is possible. The height h of the swage boss 304 of the swage plate 300 in FIG. 3 and the height H of each swage boss 414a - 414f in FIG. 4A l are not intended to be drawn to an exact scale and it should be noted that they are drawn to depict the general meaning of a height / size doubling. According to one embodiment, the height of the swage boss structure of the first series of intermittent swage boss structures 414a - 414c extending in one direction within the swage hole 132a of the carriage arm 132 is substantially equal to the height of the swage boss structure of the second series of intermittent swage boss structures 414d - 414f extending in the opposite direction within 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 of the first series of intermittent swage boss structures 414a-414c and / or each of the swage boss structures of the second series of intermittent swage boss structures 414d-414f has a substantially equal circumferential span, and according to an alternative embodiment, each of the swage boss structures of the first series of intermittent swage boss structures 414a-414c and / or each of the swage boss structures of the second series of intermittent swage boss structures 414d-414f has a circumferential span that is not substantially equal. Thus, the swage plates 410a, 410b can be optimized for a particular design scenario, for example, based on mechanical configuration and constraints, load, design goals, etc.

[0020] As described above, the number of swage boss structures (e.g., 412a-412c and 412d-412f) corresponding to each of the first and second series of intermittent swage boss structures of each of the swage plates 412a, 412b can vary from implementation to implementation, for example, based on mechanical configuration and constraints, load, design goals, etc. FIG. 4B is an exploded perspective view showing another exemplary interpose swage boss according to one embodiment. The first swage plate 420a (for the UP head) of this embodiment includes a base plate 422 and a first series of intermittent swage boss structures 424a-1 to 424a-n separated by slots, where n represents any number (here 8) of intermittent swage boss structures that can vary from implementation to implementation and that extend around the through hole 425 from the base plate 422. Similarly, the second swage plate 420b (for the DN head) of this embodiment includes a base plate 422 and a second series of intermittent swage boss structures 424b-1 to 424b-n separated by slots that extend from the base plate 422 around the 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 downward into the corresponding swage hole (see, for example, the swage hole 132a in FIGS. 1 and 2B) of the carriage arm 132 from the first side of the carriage arm 132 (for example, refer to the arm 132 in FIGS. 1 and 2B), while each of the second series of intermittent swage boss structures 424b-1 to 424b-n of the lower swage plate 420b (for the DN head) extends upward into the corresponding swage hole 132a from the second side of the carriage arm 132. According to one embodiment, here too, each intermittent swage boss structure of the first series of intermittent swage boss structures 424a-1 to 424a-n is positioned between adjacent intermittent swage boss structures of the second series of intermittent swage boss structures 424b-1 to 424b-n, that is, within the other series of corresponding slots. The respective swage boss structures of the swage plate 420a and the swage plate 420b are considered to be intervening or "connected". Thus, the first swage plate 420a couples the first suspension assembly (for example, refer to the lead suspension 110c in FIG. 1) to the first side of the carriage arm 132 via the first series of intermittent swage boss structures 424a-1 to 424a-n that extend in one direction within the swage hole 132a of the carriage arm 132, and the second swage plate 420b couples the second suspension assembly (for example, refer to the lead suspension 110c in FIG. 1) to the second opposite side of the carriage arm 132 via the second series of intermittent swage boss structures 424b-1 to 424b-n that extend in the opposite direction within the swage 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] Here too, since both the first series and the second series of intervening intermittent swage boss structures 424a-1 to 424a-n, 424b-1 to 424b-n effectively occupy the height of the same swage hole 132a, the height H of each swage boss 424a-1 to 424b-n 2 can be effectively approximately doubled from the height h in FIG. 3. For example, H 2 = approximately 2h. Therefore, even considering the thinner arm tip and the shorter corresponding swage hole compared to the configuration of the swage plate 300 in FIG. 3, a higher holding torque for the swage joint becomes possible. The height h of the swage boss 304 of the swage plate 300 in FIG. 3 and the height H of each swage boss 424a-1 to 424b-n in FIG. 4B 2 are not intended to be drawn to an exact scale and it should be noted that they are drawn to depict the general meaning of a two-fold increase in height / size. According to one embodiment, the height of the swage boss structure of the 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 structure of the 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, referring also to FIG. 4B here, 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 to 424b-n and / or each of the swage boss structures of the second series of intermittent swage boss structures 424b-1 to 424b-n has a substantially equal circumferential span, and according to an alternative embodiment, each of the swage boss structures of the first series of intermittent swage boss structures 424a-1 to 424b-n and / or each of the swage boss structures of the second series of intermittent swage boss structures 424b-1 to 424b-n has a circumferential span that is not substantially equal. Thus, the swage plates 420a, 420b can also be optimized for a particular design scenario, for example, based on mechanical configurations and constraints, loads, design goals, etc.

[0024] Method of assembling a head gimbal assembly FIG. 5 is a flow diagram showing a method of manufacturing a head gimbal assembly according to one embodiment. The head gimbal assembly (HGA) assembled, manufactured, and produced according to the method of FIG. 5 is designed, configured, and intended for implementation into a hard disk drive (HDD) (see, for example, FIG. 1).

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

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

[0027] As a result of executing blocks 502 to 504, swaging the first suspension (block 502) includes swaging a first intermittent group of extending swage boss structures 414a to 414c, 424a-1 to 424a-n that extend in one direction (e.g., downward) from a first side (e.g., upper side) of the actuator arm 132 into the swage hole 132a (e.g., see FIG. 2B) of the actuator arm 132. Swaging the second suspension (block 504) includes swaging a second intermittent group of extending swage boss structures 414d to 414f, 424b-1 to 424b-n that extend in the opposite direction (e.g., upward) from a second side (e.g., lower side) into the swage hole 132a of the actuator arm 132, and ensuring that the second intermittent group 414d to 414f, 424b-1 to 424b-n does not substantially (e.g., mechanically, structurally) interfere with the first intermittent group 414a to 414c, 424a-1 to 424a-n. This means that after swaging, there is no contact at all between any of the first intermittent swage boss structures 414a-, 414b, 414c, 424a-1 to 424a-n and the second intermittent swage boss structures 414d, 414e, 414f, 424b-1 to 424b-n, so that such structures are not cold-worked to form a mutual connection of components. Rather, there may be some contact after swaging, but such contact is not expected to prevent the intended purpose of generating a viable swage joint or connection. Therefore, a higher holding torque for the swage joint is expected, even considering the thinner arm tip and the shorter corresponding swage hole as compared to the configuration of the swage plate 300 in FIG. 3.

[0028] Physical Description of an Exemplary Operating Context 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 HDD100 is shown in FIG. 1 to facilitate describing how a conventional HDD typically operates.

[0029] FIG. 1 shows a functional arrangement of components of an HDD100 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 HDD100 includes at least one head gimbal assembly (HGA) 110 that includes the head slider, a read suspension 110c typically attached to the head slider via a flexure, and a load beam 110d attached to the read suspension 110c. The HDD100 also includes at least one recording medium 120 rotatably mounted on a spindle 124, and a drive motor (not visible) attached to the spindle 124 for rotating 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, respectively, information stored on the medium 120 of the HDD100. The medium 120 or a plurality of disk media may be fixed to the spindle 124 by a disk clamp 128.

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

[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, the HSA may include more or fewer components than those described. For example, the HSA may refer to an assembly that further includes electrical interconnect components. Generally, the HSA is an assembly configured to move a head slider to access a portion of the medium 120 for read and write operations.

[0032] Referring further to FIG. 1, electrical signals (e.g., current to voice coil 140 of the VCM) including a write signal to head 110a and a read signal from head 110a are transmitted by a flexible cable assembly (FCA) 156 (or "flex cable", or "flexible printed circuit" (FPC)). The interconnection between the flex cable 156 and the head 110a may include an arm-electronics (AE) module 160 that may have an on-board preamplifier for the read signal, as well as other read and write channel electronics. The AE module 160 may be attached to the carriage 134 as shown. The flex cable 156 may, in some configurations, be coupled to an electrical connector block 164 that provides electrical communication through an electrical feedthrough provided by the HDD housing 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 a drive motor, the voice coil 140 of the VCM, and the head 110a of the HGA 110. The electrical signal provided to the drive motor enables the drive motor to rotate while providing torque to the spindle 124, and then the torque is transmitted to the medium 120 attached to the spindle 124. As a result, the medium 120 rotates in direction 172. The rotating medium 120 forms an air cushion that acts as an air bearing on which the air bearing surface (ABS) of the slider 110b rides so that the slider 110b floats above the surface of the medium 120 without contacting the thin magnetic recording layer on which information is recorded. Similarly, in an HDD in which a gas lighter than air, such as helium as a non-limiting example, is used, the rotating medium 120 generates a gas cushion that acts as a gas or fluid bearing on which the slider 110b rides.

[0034] The electrical signal provided to the voice coil 140 of the VCM enables the head 110a of the HGA 110 to access the track 176 where information is recorded. Thus, the armature 136 of the VCM swing passing through the arc 180 enables the head 110a of the HGA 110 to access various tracks on the medium 120. Information is stored on the medium 120 within a plurality of radially nested tracks disposed in sectors on the medium 120 such as sector 184. Correspondingly, each track is composed of a plurality of sectored track portions (or "track sectors") such as sectored track portion 188. Each sectored track portion 188 may include a header containing the recorded information, error correction code information, and a servo burst signal pattern such as the ABCD servo burst signal pattern that identifies the track 176. When accessing the track 176, the read element of the head 110a of the HGA 110 reads the servo burst signal pattern, which provides a position-error-signal (PES) to the servo electronics, and the servo electronics enables the head 110a to follow the track 176 by controlling the electrical signal provided to the voice coil 140 of the VCM. After finding the track 176 and identifying a particular sectored track portion 188, the head 110a reads information from the track 176 or writes information to the track 176 in response to a command received by the disk controller from an external agent, such as a microprocessor of a computer system.

[0035] The electronic architecture of an HDD includes a number of electronic components for performing their respective functions for the operation of the HDD, such as a hard disk controller (HDC), an interface controller, an arm electronic module, a data channel, a motor driver, a servo processor, and a buffer memory. 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 disposed on a printed circuit board coupled to the bottom side of the HDD, such as the HDD housing 168.

[0036] References in this specification to hard disk drives, such as the HDD 100 shown and described with reference to FIG. 1, may include information storage devices sometimes referred to as "hybrid drives". A hybrid drive generally refers to a storage device having both functions of a conventional HDD (e.g., refer to HDD 100) combined with a solid-state storage device (SSD) that uses non-volatile memory such as flash or other solid-state (e.g., integrated circuit) memory that is electrically erasable and programmable. Since the operation, management, and control of different types of storage media are usually different, the solid-state portion of a hybrid drive may include its own corresponding controller function, and the controller function may be integrated with the HDD function into a single controller. A hybrid drive may be designed and configured to operate and utilize the solid-state portion in several ways, such as using the solid-state memory as a cache memory for storing frequently accessed data, storing I / O-intensive data, etc. Further, a hybrid drive may be essentially designed and configured as two storage devices in a single enclosure, namely a conventional HDD and an SSD, with any one of one or more interfaces for host connection.

[0037] Extensions and alternatives In the foregoing description, embodiments of the present invention have been described with reference to numerous specific details that may vary for each implementation form. Accordingly, various modifications and changes can be made without departing from the broader spirit and scope of the embodiments. Thus, the sole and exclusive indicator of what is the present invention and what the Applicants intend to be the present invention is the set of claims arising from this application, and such claims take a specific form, including any subsequent amendments. The definitions explicitly set forth herein for terms encompassed by such claims shall govern the meaning of the terms as used in the claims. Therefore, limitations, elements, characteristics, features, advantages or attributes not explicitly recited in the claims should never limit the scope of such claims. Accordingly, the present specification and drawings are to be regarded as illustrative rather than restrictive in nature.

[0038] In addition, in this specification, specific process steps may be described in a specific order, and the alphabet and alphanumeric symbols can be used to identify specific steps. Unless otherwise specified in this specification, the embodiments are not necessarily limited to any specific order of performing such steps. In particular, the symbols are merely used for convenient identification of the steps and are not intended to specify or require a specific 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 a second side of the arm via the second series of intermittent swage boss structures extending in an opposite direction 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; a hard disk drive (HDD) 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;

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 that extend 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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