Sealed hard disk drive base insert

Abstract

To increase the number of disks while maintaining sufficient rigidity and airtight sealing in a standard form factor drive.SOLUTION: The HDD300 includes a main base 306a having at least one bottom opening therethrough, a base insert 306a - 1, 306a - 2 constructed of a second material having a higher Young's Modulus than the first material and inserted into a corresponding opening 306c - 1, 306c - 2 of the main base, and a friction-stir weld (FSW) joining the base insert to the main base. The base further includes a thin film sealing material 306f between the base insert flanges 306f - 1, 306e - 2 and the main base that is heated by the FSW process and further hermetically seals the interface between the base insert and the main base. Such a base insert supports the spindle motor assembly 302 and / or the actuator assembly 304 with additional rigidity.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] Embodiments of the present invention may relate generally to hard disk drives and, more particularly, to approaches for increasing the rigidity of an enclosure base plate while maintaining a robust seal within a sealed hard disk drive. [Background technology]

[0002] A hard disk drive (HDD) is a nonvolatile storage device that stores digitally encoded data on one or more circular disks with magnetic surfaces housed in a protective enclosure. 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 disk using a read-write head (or "transducer") housed on a slider positioned over specific locations 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 current flowing through the write head's coil. Electrical pulses are sent to the write head with different patterns of positive and negative current. The current in the write head's coil generates a localized magnetic field across the gap between the head and the magnetic-recording disk, which in turn magnetizes small areas on the recording medium.

[0003] As the number and power of networked computing systems increases, more data storage system capacity is required. Cloud computing and large-scale data processing further increase the need for digital data storage systems capable of transferring and retaining large amounts of data. To this end, increasing the storage capacity of HDDs is one of the continuing goals in the evolution of HDD technology. In one form, this goal manifests itself in increasing the number of disks within a given HDD.

[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. 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 explanation 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 numerals refer to similar elements and in which: [Figure 1] 1 is a plan view illustrating a hard disk drive (HDD), according to one embodiment. [Figure 2] FIG. 2 is a cross-sectional side view showing the power system of the HDD. [Figure 3] 1 is a cross-sectional side view of an HDD according to one embodiment. [Figure 4] 4 is a cross-sectional side view illustrating a mounting approach for the HDD of FIG. 3, according to one embodiment. [Figure 5A] 1 is a cross-sectional side view of an HDD according to one embodiment. [Figure 5B] FIG. 5B is a perspective view of a base insert for the HDD of FIG. 5A, according to one embodiment. [Figure 6] 1 is a flowchart illustrating a method for manufacturing a hard disk drive enclosure base, according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0006] Generally, an approach for increasing or maintaining the rigidity of thinner enclosure base plates while maintaining a robust seal within a sealed hard disk drive (HDD) is described. 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. It will be apparent, however, 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 shown 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," etc. 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., but 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 describes a structure as "substantially vertical," the term is assigned its obvious meaning, such that the sidewalls are for all practical purposes vertical, but may not be at exactly 90 degrees.

[0009] Although terms such as "optimal," "optimize," "minimum," "minimize," "maximum," "maximize," and the like may not have specific values ​​associated with them, when such terms are used herein, it is intended that one of ordinary skill in the art will understand such terms to include affecting a value, parameter, metric, etc. in a beneficial direction consistent with the entirety of this disclosure. For example, describing something 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] The term "airtight" will be understood to describe a sealing arrangement that is designed to have nominally no (or negligible) leakage or permeation paths for gases. It should be noted that although terms such as "airtight," "negligible leakage," and "leak-free" may be used herein, such systems often still have a certain amount of permeability and therefore are not absolutely leak-free.

[0011] context Recall that increasing the storage capacity of hard disk drives (“HDDs,” or simply “drives”) is one of the continuing goals in the evolution of HDD technology, and increasing the number of recording disks to provide more disk storage space is one approach to increasing overall storage capacity. However, maintaining a standard form factor, as characterized in part by the HDD’s z-height, is often required, which inherently presents challenges with fitting more disks into a given HDD. More specifically, customer specifications and / or common design and operational constraints include operational shock (or “op-shock”) requirements, which generally relate to the HDD’s operational tolerance to mechanical shock events. Furthermore, the ability of a servo system to position a read-write head over a target tracking position (“track center”) and track the target tracking position due to disk rotation (e.g., “track following”) can be affected by many factors, including drive disturbances such as internal and external operational vibration (“op-vibe”) events or occurrences.

[0012] Thus, challenges remain for increasing the number of disks while maintaining a standard form factor and ensuring operational shock and vibration requirements are met. For example, one issue that may arise with increasing the number of disks in a standard form factor drive is that a thinner enclosure base plate (e.g., a thinner floor) may be implemented to provide more available z-height to pack more disks and corresponding actuator arms into the drive enclosure. HDD operation requires the operation of both the disk spindle motor and the head stack assembly (HSA) actuator, both of which are mechanically coupled to the base plate in some way. One possible approach to meeting design and operational requirements is to use a high-rigidity material, such as steel, for the base plate; however, steel is difficult to cast in large quantities and, being a harder material, requires longer post-cast machining times.

[0013] Another approach to meeting the requirements involves inserting different materials to connect to the base plate in the area of ​​the disk spindle motor and / or actuator assembly to increase the stiffness of each power system. Figure 2 is a cross-sectional side view of a power system of an HDD. The HDD 200 includes a disk spindle motor system 202 and an HSA actuator system 204 housed within an HDD enclosure 206, which includes a base 206a (or "enclosure base" or "base plate"; see, e.g., housing 168 in Figure 1) and a cover 206b, typically made of cast aluminum. Here, the motor shaft 203a of the spindle motor 203 of the disk spindle motor system 202 may be made of steel rather than aluminum like the base 206a. Similarly, the pivot shaft 205a of the pivot 205 of the actuator system 204 may also be made of steel rather than aluminum like the base 206a. However, such steel shaft inserts 203a, 205a have a relatively small mechanical interface with the base 206, are not structurally integral with the base 206, and therefore may be insufficient to provide the desired base plate stiffness. Therefore, the robustness of both electrical systems, e.g., the disk spindle motor system 202 and the actuator system 204, may be reduced with such thinner, less stiff base plates.

[0014] Yet another approach to this base stiffness problem involves inserting support structures with a higher Young's modulus (i.e., the mechanical property of a solid material that characterizes its tensile or compressive stiffness, e.g., defined as the ratio of tensile stress to tensile strain) into the base plate in the region of the disk spindle motor and / or actuator assembly to locally increase the stiffness of the base plate. However, high-capacity HDDs (e.g., those used in data centers) are currently likely to be hermetically sealed drives operating with an internal lighter-than-air gas (e.g., helium, as a non-limiting example) from a total cost of ownership (TCO) perspective. For example, because helium has a density one-seventh that of air, there are various advantages to sealing and operating HDDs in a helium atmosphere. Therefore, operating an HDD in helium reduces the drag forces acting on the rotating disk stack and the mechanical power used by the disk spindle motor. Furthermore, operating in helium reduces disk and suspension flutter, allowing for smaller, narrower data track pitches, allowing disks to be placed closer together and disks to increase areal density (a measure of the number of information bits that can be stored in a given area of ​​the disk surface). Helium's lower shear forces and more efficient heat conduction also mean that HDDs run cooler and emit less acoustic noise. However, the rigid structure inserted into the baseplate casting introduces potential new leak paths. Given the above, the challenge remains to increase the number of disks while maintaining sufficient rigidity in standard form-factor drives and maintaining an effective, hermetically sealed enclosure.

[0015] High rigidity material insert into base plate 3 is a cross-sectional side view of an HDD, according to an embodiment. The HDD 300 includes a disk spindle motor assembly 302 and an HSA actuator assembly 304 ("actuator assembly 304") housed within an HDD enclosure 306, which includes a main base 306a (or "enclosure base" or "base plate"), typically cast aluminum, and a cover 306b. The motor shaft 303a of the spindle motor 303 of the disk spindle motor assembly 302 may be constructed from steel rather than aluminum like the main base 306a. Similarly, the pivot shaft 305a of the pivot 305 of the actuator assembly 304 may also be constructed from steel rather than aluminum like the main base 306a. According to at least one embodiment, the main base 306a is constructed from a first material and includes at least one bottom opening therethrough, shown herein as first opening 306a-1 and second opening 306a-2. The enclosure 306 further comprises at least one base insert, herein designated as first base insert 306c-1 and second base insert 306c-2, each constructed from a second material having a higher Young's modulus (e.g., more rigidity) than the first material, inserted into a corresponding bottom opening 306a-1, 306a-2 in the main base 306a. For example, the main base 306a may be constructed from aluminum / aluminum alloy, and each base insert 306c-1, 306c-2 may be constructed from steel / steel alloy.

[0016] According to at least one embodiment, each base insert 306c-1, 306c-2 includes a respective flange 306f-1, 306f-2 structure to increase strength for mitigating the effects of external shock and vibration. According to at least one embodiment, base insert 306c-1 is positioned below and coupled to motor shaft 303a of spindle motor assembly 302. According to at least one embodiment, base insert 306c-2 is positioned below and coupled to pivot shaft 305a of HSA actuator assembly 304. According to at least one embodiment, as depicted in FIG. 3, base insert 306c-1 is positioned below and coupled to motor shaft 303a of spindle motor assembly 302, and base insert 306c-2 is positioned below and coupled to pivot shaft 305a of HSA actuator assembly 304.

[0017] The enclosure 306 further comprises friction stir welds (FSW), herein designated as FSW 306d-1-1 and FSW 306d-1-2 for the first base insert 306c-1 and FSW 306d-2-1 and FSW 306d-2-2 for the second base insert 306c-2, which couple each of the at least one base insert 306c-1, 306c-2 to the main base 306a. Generally, FSWs such as FSW306d-1-1, FSW306d-1-2, FSW306d-2-1, and FSW306d-2-2 are produced by friction stir welding, a joining process considered to have very high weld strength, which uses a tool to join parts by generating heat through friction between the rotating tool and the target part material, softening the area near the tool and effectively forging the high-temperature softened metal, thereby mechanically mixing the two metal pieces. According to at least one embodiment, base insert 306c-1 comprises flange 306f-1 having an outer diameter (e.g., of a thinner outer portion) where (optionally, a “first”) FSW 306d-1-1 is created at the outer interface of flange 306f-1 and main base 306a at opening 306a-1, and an inner diameter (e.g., of a thinner outer portion) where (optionally, a “second”) FSW 306d-1-2 is created at the inner interface of flange 306f-1 and main base 306a at opening 306a-1. Similarly, according to at least one embodiment, base insert 306c-2 comprises flange 306f-2 having an outer diameter where (optionally, a "first") FSW 306d-2-1 is created at the outer interface of flange 306f-2 and main base 306a at opening 306a-2, and an inner diameter where (optionally, a "second") FSW 306d-2-2 is created at the inner interface of flange 306f-2 and main base 306a at opening 306a-2.

[0018] At least in part due to the relatively large flange profile of each of the at least one base insert 306c-1, 306c-2, it may be difficult to join, bond, or attach each entire interface solely by friction stir welding due to the risk of gaps in the flange 306f-1, 306f-2 region between each base insert 306c-1, 306c-2 and the main base 306a. According to at least one embodiment, a membrane is inserted and utilized in the flange region between the base insert and the main base to eliminate this risk of gaps. Figure 4 is a cross-sectional side view illustrating an attachment approach for the HDD of Figure 3, according to one embodiment. 4 illustrates the interface between the main base 306a and representative base inserts 306c-1, 306c-2, further depicting FSWs 306d-1-1, 306d-2-1 at the outer diameter of the base insert flanges 306f-1, 306f-2 and FSWs 306d-1-2, 306d-2-2 at the inner diameter of the base insert flanges 306f-1, 306f-2, as described in more detail elsewhere herein. According to at least some embodiments, the enclosure 300 further includes a sealing material 306e between at least a portion of the flanges 306f-1, 306f-2 of the corresponding base inserts 306c-1, 306c-2 and the main base 306a. For example, the sealing material 306e may be implemented as a thin-film material that may melt at a lower temperature than steel and aluminum. For example, according to an embodiment, the encapsulation material may be selected from at least one of a lead-free solder, a brazing material, and a thermoplastic resin. Such thin-film encapsulation material 306e may be melted by the heat residue (represented by the wavy arrows) from the FSW process, and this molten material fills any gaps and further welds, bonds, connects, or attaches one or both base inserts 306c-1, 306c-2 to the main base plate 306a. Preferably, according to an embodiment, the thickness of the thin-film encapsulation material 306e (as applied before heating) should be thinner (e.g., as a non-limiting example, less than 0.1 mm), annular in shape, and smaller in size than the radius of the corresponding flanges 306f-1, 306f-2.

[0019] Reduced disc windage losses 5A is a cross-sectional side view of an HDD according to one embodiment. Similar to the HDD 300 of FIGS. 3 and 4, the HDD 500 includes a disk spindle motor assembly 502 housed within an HDD enclosure 506 including a main base 506a and a cover 506b, typically made of cast aluminum. The motor shaft 503a of the spindle motor 503 of the disk spindle motor assembly 502 may be constructed from steel rather than aluminum like the main base 506a. Similar to the HDD 300, according to at least one embodiment, the main base 506a is constructed from a first material and includes at least one bottom opening therethrough, herein shown as first opening 506a-1. The enclosure 506 further includes at least one base insert, herein designated as base insert 506c-1, constructed of a second material having a higher Young's modulus (e.g., greater stiffness) than the first material, inserted into a corresponding bottom opening 506a-1 of the main base 306a. For example, the main base 506a may be constructed of aluminum / aluminum alloy, and each base insert 506c-1 may be constructed of steel / steel alloy. Again, the base insert 506c-1 is constructed with a flange structure for increased strength to mitigate the effects of external shock and vibration, and the base insert 506c-1 is positioned below and coupled to the motor shaft 503a of the spindle motor assembly 502. It should be noted that the enclosure 506 of the HDD 500 may further comprise a second base insert, such as base insert 306c-2 (FIG. 3), positioned below and coupled to a pivot shaft, such as pivot shaft 305a (FIG. 3) of the HSA actuator assembly 304 (FIG. 3). Similar to the HDD 300 of FIGS. 3 and 4, the enclosure 506 further comprises friction stir welds (FSWs), shown herein as FSWs 506d-1-1 and 506d-1-2, respectively, at each of the outer and inner diameters of the flange (e.g., in the thinner outer portion of flange 506f), which couple the base insert 506c-1 to the main base 506a.Also herein, according to at least one embodiment, a thin film encapsulant 506e is utilized on the outer flange area between the base insert 506c-1 and the main base 506a. Also herein, the encapsulant 506e may have the same attributes as those described with reference to the encapsulant 306e (FIGS. 3 and 4).

[0020] “Windage” generally refers to the air resistance of a moving object or the retarding force of air friction on a moving object. In the context of HDDs, windage often refers to the effect of air / gas resistance on a rotating disk due to nearby structures. For example, tight disk clearance corresponding to the HDD enclosure and disk shroud structure creates more windage drag, requiring the spindle motor to use more power. Thus, reducing windage-based power loss (“windage loss”) is typically considered beneficial. Of note with respect to the HDD 500, according to at least one embodiment, the base insert 506c-1 includes a portion that extends beyond the spindle motor assembly 502 to below the disk stack 508, and this portion includes one or more grooves 506f-1 in a surface facing the bottom disk 508b. Thus, disk windage loss can be reduced by having a larger gap between the bottom disk 508b and the base insert 506c-1. As depicted, flange 506 f may extend further radially below disc stack 508 to provide a surface for mating, adhering, or bonding with a surface of main base 506 .

[0021] Figure 5B is a perspective view illustrating a base insert for the HDD of Figure 5A, according to one embodiment. Base insert 556c-1 illustrates an exemplary implementation of base insert 506c-1 of Figure 5A, depicting a set of five annular grooves 556f-1 etched, machined, or otherwise formed around annular base insert 556c-1, rather than the simplified diagram of Figure 5A depicting two groove sets for base insert 506c-1. Note that the number of grooves formed in a given base insert may vary from implementation to implementation, based on, by way of non-limiting example, design goals and operating parameters, manufacturing process, cost, etc. As an alternative to providing one or more grooves 506f-1, 556f-1 in the base insert 506c-1, 556c-1, a simple gap or recess may be implemented and formed in the base insert, such as the base insert 506c-1, 556c-1, facing the bottom disk 508b surface, to reduce windage loss.

[0022] Hard disk drive enclosure base manufacturing method 6 is a flowchart illustrating a method for manufacturing a hard disk drive enclosure base, according to one embodiment. For example, the manufacturing method of FIG. 6 can be used to manufacture HDD enclosure bases such as base 306 (FIGS. 3 and 4), 506 (FIG. 5A), etc.

[0023] In block 602, a main base is formed that is constructed from a first material and has at least one opening through the floor of the main base. For example, main base 306a (FIGS. 3 and 4) with first opening 306a-1 (FIGS. 3 and 4) and / or second opening 306a-2 (FIGS. 3 and 4), or main base 506a (FIG. 5A) with first opening 506a-1 (FIG. 5A) (and / or second opening, such as 306a-2), is cast from aluminum.

[0024] In block 604, a base insert with a flange is inserted into a corresponding opening in the main base, the base insert being made of a second material having a higher Young's modulus than the first material. For example, a first base insert 306c-1 (FIGS. 3 and 4) and / or a second base insert 306c-2 (FIGS. 3 and 4) made of steel (for example, fabricated from steel sheet) is inserted into the corresponding first opening 306a-1, second opening 306a-2 in the main base 306a. In another example, a first base insert 506c-1 (FIGS. 5A and 5B) (and / or a second base insert such as 306c-2) made of steel (for example, fabricated from steel sheet) is inserted into the corresponding first opening 506a-1 (and / or second opening such as 306a-2) in the main base 506a.

[0025] At block 606, a thin film encapsulant is positioned over at least a portion of the flange. For example, a thin film of encapsulant 306e (FIGS. 3 and 4), 506e (FIG. 5A) is positioned over at least a portion of flange 306f-1, 306f-2, 506f of base insert 306c-1, 306c-2, 506c-1.

[0026] At block 608, the base inserts are bonded to the main base using friction stir welds (FSW), thereby melting the thin film sealing material. For example, base inserts 306c-1, 306c-2 are joined to the corresponding main base 306a by FSW 306d-1-1, 306d-1-2, 306d-2-1, 306d-2-2 (FIGS. 3 and 4), thereby melting the sealing material 306e and further hermetically sealing each base insert 306c-1, 306c-2 to the main base 306a. In another example, base insert 506c-1 (and / or a second base insert such as 306c-2) is joined to the corresponding main base 506a by 506d-1-1, 506d-1-2 (FIG. 5), thereby melting the sealing material 506e and further hermetically sealing each base insert 506c-1 to the main base 506a.

[0027] Further, the HDD spindle motor assembly may be coupled to the first base insert, and the head stack assembly actuator assembly may be coupled to the second base insert. For example, the HDD spindle motor assembly 302 (FIG. 3) may be coupled to the first base insert 306c-1, and the head stack assembly actuator assembly 304 (FIG. 3) may be coupled to the second base insert 306c-2.

[0028] Therefore, the HDD enclosure base described throughout this specification, which includes a rigid insert structure to support one or both of the power systems and is robustly sealed to the main base plate via friction stir welds and thin film sealing material at the interface, provides an approach to increasing the number of disks while maintaining sufficient rigidity in standard form factor drives and maintaining an effective hermetically sealed enclosure.

[0029] Illustrative physical description of the operating context Embodiments may be used in the context of a digital data storage device (DSD), such as a hard disk drive (HDD). Accordingly, according to embodiments, a plan view illustrating a conventional HDD 100 is shown in FIG. 1 to help describe how a conventional HDD typically operates.

[0030] FIG. 1 shows the functional layout of components of a HDD 100, including a slider 110b that includes a magnetic read-write head 110a. Collectively, the slider 110b and 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 typically attached to the head-slider via a flexure, and a load beam 110d attached to the lead suspension 110c. The HDD 100 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 information stored on the medium 120 of the HDD 100, respectively. The medium 120 or multiple disk media may be secured to the spindle 124 with a disk clamp 128 .

[0031] HDD 100 further includes an arm 132 attached to HGA 110, a carriage 134, and a voice coil motor (VCM) including an armature 136 including a voice coil 140 attached to carriage 134, and a stator 144 including a voice coil magnet (not shown). The VCM's armature 136 is attached to carriage 134 and configured to move arm 132 and HGA 110 to access a portion of media 120, all collectively mounted on a pivot shaft 148 with an intervening pivot bearing assembly 152. In HDDs with multiple disks, 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.

[0032] 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 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 fewer components than those listed. For example, an HSA may refer to an assembly that further includes electrical interconnection components. Generally, an HSA is an assembly configured to move a head slider to access portions of medium 120 for read and write operations.

[0033] With further reference to FIG. 1, electrical signals (e.g., current to the voice coil 140 of the VCM), including write signals to and read signals from the head 110a, are transmitted through a flexible cable assembly (FCA) 156 (or "flex cable," or "flexible printed circuit"). The signal is transmitted by a flexible printed circuit (FPC). The interconnection between the flex cable 156 and the head 110a may include an arm-electronic (AE) module 160, which 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 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 electrical feedthroughs provided by the HDD housing 168. The HDD housing 168 (or "enclosure base," or "base plate," or simply "base"), in conjunction 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.

[0034] 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 torque to the spindle 124, which is then transmitted 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 upon which the air-bearing surface (ABS) of the slider 110b rides, acting as an air bearing 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 utilizing a lighter-than-air gas such as helium, as a non-limiting example, the rotating medium 120 creates a cushion of gas on which the slider 110b rides, acting as a gas or fluid bearing.

[0035] An electrical signal provided to the voice coil 140 of the VCM enables the head 110a of the HGA 110 to access tracks 176 where information is to be recorded. Thus, the armature 136 of the VCM swings through an arc 180, enabling the head 110a of the HGA 110 to access various tracks on the medium 120. Information is stored on the medium 120 in a plurality of radially nested tracks arranged in sectors on the medium 120, such as sector 184. Correspondingly, each track is made up of a plurality of sectored track portions (or "track sectors"), such as sectored track portion 188. Each sectored 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, that identifies the track 176. When accessing track 176, a read element of head 110a of HGA 110 reads the servo burst signal pattern, which provides a position-error-signal (PES) to the servo electronics, which in turn controls the electrical signal provided to the voice coil 140 of the VCM, thereby enabling head 110a to follow track 176. 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 in a computer system.

[0036] The electronic architecture of an HDD includes numerous electronic components, such as a hard disk controller ("HDC"), interface controller, arm electronics module, data channel, motor drivers, servo processor, buffer memory, etc., each performing a different function for the operation of the HDD. Two or more of these components may be combined on a single integrated circuit board called a "system on a chip" ("SOC"). Some, if not all, of these electronic components are typically located on a printed circuit board that is coupled to the bottom side of the HDD, such as HDD housing 168.

[0037] References herein to hard disk drives, such as HDD 100 shown and described with reference to FIG. 1, may encompass information storage devices sometimes 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), which 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 a 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 cache memory to store frequently accessed data, I / O-intensive data, etc., as non-limiting examples. Additionally, a hybrid drive may be essentially designed and configured as two storage devices, a traditional HDD and an SSD, in a single enclosure, with either one or multiple interfaces for host connection.

[0038] Extensions and Substitutes In the foregoing description, embodiments of the present 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 to the invention, and what applicants intend to be the invention, is the set of claims issuing from this application, and the particular form from which such claims originate, including any subsequent amendments. The definitions expressly set forth herein for terms contained in such claims shall control the meaning of those terms as used in the claims. Therefore, no limitation, element, property, feature, advantage, or attribute not expressly recited in a claim should in any way limit the scope of such claim. The specification and drawings are hereby to be regarded in an illustrative, and not restrictive, sense.

[0039] It should be noted that certain process steps may be described herein in a particular order, and alphabetic and alphanumeric symbols may be used to identify certain 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 hard disk drive (HDD), a disk medium rotatably mounted on a spindle; a spindle motor assembly configured to rotate the spindle on which the disk media is mounted; a head slider containing a read-write transducer configured to read from and write to the disk medium; a head stack assembly (HSA) actuator assembly configured to move the head slider to access a portion of the disk medium; an enclosure, the enclosure comprising: a main base constructed from a first material and having at least one bottom opening therethrough; a base insert, the base insert being constructed from a second material having a higher Young's modulus than the first material, for insertion into a corresponding bottom opening of the main base; a friction stir weld (FSW) joining the base insert to the main base.

2. 2. The HDD of claim 1, wherein the base insert is positioned below and coupled to a motor shaft of the spindle motor assembly.

3. 3. The HDD of claim 2, wherein the base insert comprises a portion that extends beyond the spindle motor assembly, the portion comprising one or more grooves in a surface facing the disk media.

4. 2. The HDD of claim 1, wherein the base insert is positioned below and coupled to a pivot shaft of the HSA actuator assembly.

5. a first base insert positioned below and coupled to a motor shaft of the spindle motor assembly; 2. The HDD of claim 1, wherein a second base insert is positioned below and coupled to a pivot shaft of the HSA actuator assembly.

6. the base insert includes a flange portion having an inner diameter and an outer diameter; The FSW is a first weld at an interface between the inner diameter of the flange portion and the main base; 10. The HDD of claim 1, further comprising: a second weld at an interface between the outer diameter of the flange portion and the main base.

7. the base insert includes a flange portion; The HDD of claim 1 , wherein the enclosure further comprises a sealing material between at least a portion of the flange portion and the main base.

8. 8. The HDD of claim 7, wherein the sealing material comprises a thin film of one material from the group consisting of lead-free solder, brazing material, and thermoplastic resin.

9. 8. The HDD of claim 7, wherein the sealing material is comprised of a material having a lower melting point than the main base and the base insert, such that the sealing material is melted by heat from fabricating the FSW.

10. 1. A hard disk drive (HDD) enclosure, comprising: a main base constructed from a first material and having at least one floor opening therethrough; a base insert, the base insert being constructed from a second material having a higher Young's modulus than the first material, for insertion into a corresponding floor opening in the main base; a friction stir weld (FSW) joining the base insert to the main base.

11. 11. The HDD enclosure of claim 10, wherein the base insert is configured for positioning beneath a HDD spindle motor assembly.

12. 12. The HDD enclosure of claim 11, wherein the base insert comprises a portion with one or more grooves on a top surface, the portion configured for positioning beneath a HDD disk media.

13. 11. The HDD enclosure of claim 10, wherein the base insert is configured for positioning below a head stack assembly actuator assembly.

14. 11. The HDD enclosure of claim 10, wherein the first base insert is configured for positioning below a HDD spindle motor assembly and the second base insert is configured for positioning below a head stack assembly actuator assembly.

15. the base insert includes a flange portion having an inner diameter and an outer diameter; The FSW is a first weld at an interface between the inner diameter of the flange portion and the main base; 11. The HDD enclosure of claim 10, further comprising a second weld at an interface between the outer diameter of the flange portion and the main base.

16. the base insert includes a flange portion; The HDD enclosure of claim 10 , wherein the enclosure further comprises a sealing material between at least a portion of the flange portion and the main base.

17. 17. The HDD enclosure of claim 16, wherein the sealing material comprises a thin film of one material from the group consisting of lead-free solder, brazing material, and thermoplastic resin.

18. A hard disk drive comprising the HDD enclosure of claim 10.

19. 1. A method of manufacturing a hard disk drive (HDD) enclosure base, the method comprising: forming a main base constructed from a first material, the main base having at least one opening through a floor of the main base; inserting a base insert having a flange into a corresponding opening in the main base, the base insert being constructed from a second material having a higher Young's modulus than the first material; positioning a thin film encapsulant material over at least a portion of the flange; and bonding the base insert to the main base using friction stir welding (FSW), thereby melting the thin film encapsulation material.

20. inserting the base inserts includes inserting a first base insert into a corresponding first opening of the main base and inserting a second base insert into a corresponding second opening of the main base, the flange of each base insert having an inner diameter and an outer diameter; coupling each base insert to the main base includes forming a first FSW weld at an interface between the inner diameter of the respective flange and the main base, and forming a second FSW weld at an interface between the outer diameter of the respective flange and the main base; The method comprises: coupling a HDD spindle motor assembly to the first base insert; 20. The method of claim 19, further comprising: coupling a head stack assembly actuator assembly to the second base insert.

Images