Modular architecture for hard disk drive storage system

Abstract

The invention relates to a modular architecture for a hard disk drive storage system. A modular data storage system includes a shared master PCB including at least one system controller configured to operate with a plurality of stacked storage devices, such as modified hard disk drives, the plurality of stacked storage devices being configured to store a plurality of data stored in the shared master PCB, the plurality of stacked storage devices being configured to store a plurality of data stored in the shared master PCB. Wherein a majority of the driver-specific components are held on each driver. Each storage device is mechanically and electrically connected to the main PCB at or near one end of the storage device, and the controller is centrally positioned on the main PCB such that the total electrical transmission line length between the storage device and the controller circuitry is minimized. In addition, the controller circuit may be positioned on the main PCB such that each electrical transmission line length between a respective storage device and the controller circuit is substantially equal. For high-speed interfaces, signal integrity is significantly simplified, and for low-speed interfaces, shorter interconnects help meet timing requirements.

Description

Technical Field

[0001] Various embodiments of the present invention may relate generally to data storage, and more specifically to high-density and flexible hard disk drive storage platforms. Background Technology

[0002] A hard disk drive (HDD) is a non-volatile storage device that is housed in a protective casing and stores digitally encoded data on one or more circular disks with magnetic surfaces. When an HDD is in operation, each magnetic recording disk is rapidly rotated by a spindle system. Read / write heads (or transducers), positioned above specific locations on the disk by actuators, read data from and write data to the magnetic recording disk. The read / write heads use magnetic fields to write data onto and read data from the surface of the magnetic recording disk. The write head operates by using current flowing through its coils, thereby generating a magnetic field. Electrical pulses are delivered to the write head in different modes of positive and negative current. The current in the coils of the write head generates a localized magnetic field in the gap between the head and the disk, which in turn magnetizes a small area on the recording medium.

[0003] As the number and capacity of networked computing systems grow, the demand for data storage capacity also increases. Enterprises, cloud computing / storage, and large-scale data processing environments further increase the need for digital data storage systems (typically "data centers") capable of delivering and accommodating large amounts of data. One approach to providing sufficient data storage for data centers is to use arrays of data storage devices that are typically configured and configured as one or more data storage systems. For example, one such approach for large-scale data storage is called a JBOD (Disk Cluster or Drive Cluster), which is typically a collection of hard disk drives (HDDs) that can be exposed as individual devices or combined to operate as a single logical volume.

[0004] Furthermore, the demand for archived data storage (also known as "cold storage") is constantly increasing. Magnetic tape is a common solution for data backup, but accessing the stored data is very slow. Current archives are increasingly becoming "active" archives, meaning a certain degree of continuous random access is required. In addition to faster access times, disk databases offer many advantages over conventional tape libraries. In terms of magnetic media cost, disks in HDDs have the lowest cost per terabyte (e.g., $ / Tb). Furthermore, disks are known to have a relatively long lifespan (especially when kept in a controlled environment), whereby the magnetic potential on the medium remains stable for a relatively long period.

[0005] Any method that may be described in this section is a feasible method, but not necessarily a method that has been previously conceived or implemented. Therefore, unless otherwise stated, no method described in this section should be considered prior art simply because it is included in this section. Attached Figure Description

[0006] The embodiments are illustrated in the accompanying drawings by way of example rather than limitation, in which the same reference numerals refer to similar elements and wherein:

[0007] Figure 1 This is a plan view illustrating a hard disk drive (HDD) according to an implementation scheme;

[0008] Figure 2 This is a schematic perspective view illustrating a modular data storage system according to the implementation plan;

[0009] Figure 3A This is a perspective view illustrating a hard disk drive with interposer electrical connections according to an embodiment;

[0010] Figure 3B This is a perspective view illustrating a hard disk drive with custom-designed housing electrical connections according to an implementation scheme;

[0011] Figure 4A This is a schematic diagram illustrating a single-channel modular data storage system according to the implementation plan;

[0012] Figure 4B This is a schematic diagram illustrating a dual-channel modular data storage system according to the implementation plan;

[0013] Figure 5A This is a side view schematic diagram illustrating a modular data storage system with interposer electrical connectors according to an embodiment;

[0014] Figure 5B This is a side view schematic diagram illustrating a modular data storage system with customized housing electrical connections according to an implementation scheme;

[0015] Figure 6A This is a perspective view illustrating a modular data storage system with interpolator electrical connections according to an implementation scheme;

[0016] Figure 6B This is an example based on the implementation plan. Figure 6A A perspective view of the electrical connections of a modular data storage system;

[0017] Figure 6C This is an example based on the implementation plan. Figure 6A A perspective view of the interposer board of a modular data storage system;

[0018] Figure 7 This is a side view schematic diagram illustrating a modular data storage system with interpolator electrical connections according to an embodiment; and

[0019] Figure 8This is a table illustrating the options for interposer electrical connections according to the implementation scheme. Detailed Implementation

[0020] Generally, methods for high-density modular data storage platforms are described. In the following description, numerous specific details are set forth for purposes of explanation in order to provide a thorough understanding of the embodiments of the invention described herein. However, it will be apparent, however, that the embodiments of the invention described herein can be practiced without these specific details. In other instances, well-known structures and devices may be shown in block diagram form to avoid unnecessarily obscuring the embodiments of the invention described herein.

[0021] introduction

[0022] the term

[0023] References to "implementation," "an embodiment," etc., herein are intended to mean that a particular feature, structure, or characteristic described is included in at least one embodiment of the invention. However, instances of such phrases do not necessarily refer to the same embodiment.

[0024] The term "substantially" should be understood as describing features that are mostly or nearly structured, configured, sized, etc., but in practice, manufacturing tolerances and other factors may cause the structure, configuration, dimensions, etc., to not always or necessarily be as precise as described. For example, describing a structure as "substantially vertical" would give the term its general meaning that the structure is vertical in all practical applications, but its overall orientation may not be exactly 90 degrees.

[0025] While terms such as “optimal,” “minimum,” “maximum,” “maximize” may not have certain values ​​associated with them, if such terms are used herein, it is intended that those skilled in the art will understand that such terms will include values, parameters, measures, etc., that influence in a beneficial direction consistent with the whole of this disclosure. For example, describing the value of something as “minimum” does not require that the value is actually equal to some theoretical minimum (e.g., zero), but should be understood in a practical sense as the corresponding objective being to move that value toward the theoretical minimum in a beneficial direction.

[0026] Context

[0027] To recap, the demand for archived data storage continues to grow alongside the ongoing needs of enterprises, cloud computing, storage, and large-scale data processing data centers. One approach to meeting the broad demand for storage of any form involves using decomposed storage, where compute resources are typically separated from storage resources. This allows different types of resources to be suited for separate provisioning, control, maintenance, etc. However, maximizing the potential benefits of decomposed storage can also benefit from flexible, high-density storage platform architectures. For example, one aspect of storage platform flexibility can include enabling the use of both faster (relatively high IOPS or input / output per second) and slower (relatively low IOPS) storage devices. Furthermore, any architecture implemented for a high-density storage platform should not avoid considering the performance and cost associated with the underlying storage devices.

[0028] Previous known methods for archiving storage platforms utilizing shared electronics relied on significantly large PCBs (printed circuit boards) to serve data storage arrays, requiring long electrical transmission lengths and potentially high-frequency electrical multiplexers. These requirements, in turn, could necessitate the use of low-loss, high-cost PCB laminates, for example, up to five times the cost of conventional PCB laminates.

[0029] Modular architecture for hard disk drive storage platforms

[0030] According to the implementation scheme, the hard disk drive (HDD) multi-modal (HD-MM) architecture / design enables HDDs to be configured in a variety of ways and capacities. Therefore, an HDD can operate in a single drive mode or as part of a group of other HDDs operating via a shared printed circuit board (PCB) comprising one or more electronic controllers (also referred to as controller circuitry or a “SOC” (System-on-a-Chip)). Thus, such data storage systems implemented in HD-MM form can accommodate both low-latency / IOPS and high-latency / IOPS configurations. For example, an HD-MM storage system can be configured using an “NxHDD T” configuration with a single controller or an “NxHDD Parallel” configuration with multiple controllers. In an NxHDD T configuration, one or more T-connectors (“T-connectors”) can be implemented to branch from multiple HDDs (e.g., interchangeable HDDs primarily utilizing existing electronics) to a single controller. Alternatively, the NxHDD parallel configuration can be used to emulate a multi-actuator architecture, where each controller operates independently with a corresponding logic unit of memory corresponding to the HDD, while utilizing existing HDD mechanisms. In either type of configuration, it is intended that the constituent HDDs be interchangeable with both the NxHDD parallel configuration and the NxHDD T configuration.

[0031] Figure 2This is a schematic perspective view illustrating a modular data storage system according to the implementation plan. Figure 2 An example “8x” data storage system 200 with eight HDDs 202 is illustrated only. Each HDD is coupled to or mounted to a common (i.e., shared) main PCB 204, for example, communicating with the common (i.e., shared) main PCB mechanically and electrically. Exemplary dimensions are included herein to depict a four-stack configuration (four HDDs stacked one on top of the others). Such systems can be mounted in 4U slots in multiple orientations (e.g., main PCB down, main PCB rearward), where “U” or “RU” refers to a standard rack unit or a unit of measurement defined as 1.75 inches (44.45 mm) in height. With rack mounting of the main PCB 204 downwards (on the bottom), the system / box can be serviced from the top, and therefore the HDDs 202 can be easily replaced.

[0032] According to the implementation plan, the HDD configured for this HD-MM architecture can be one of two types. Figure 3A This is a perspective view illustrating a hard disk drive with interposer electrical connectors according to an embodiment. Figure 3A An HDD 302 configured for an interpolator electrical connector is illustrated; this HDD is referred to herein as an HDD-IC (HDD-Interpolator Connector). The HDD-IC form factor shows almost no physical placement change compared to a conventional HDD PCB because it utilizes current / conventional electronics other than the main controller / SOC. For example, the preamplifier, actuator controller (e.g., voice coil motor (VCM), trimmer actuator), motor controller (e.g., disk spindle motor), and sensor (e.g., temperature, rotational vibration, etc.) circuitry are all maintained on a modified PCB 304 to support the low-cost end connector 305 bus input; that is, the interpolator board / bus is thus used to support the HDD-IC with a separate main PCB (see example...). Figure 2 The main PCB 204 contains I / O (multiple inputs / outputs) between the main controller and additional control (if required). According to the implementation, by utilizing the HDD-IC form factor, the conventional HDD housing can be used to minimize manufacturing complexity and cost, and the associated interpolator PCB is a low-cost, minimal-layer PCB (e.g., for a non-limiting example, a four-layer PCB with fewer through-holes).

[0033] Figure 3B This is a perspective view illustrating a hard disk drive with custom-designed housing electrical connections according to an implementation scheme. Figure 3BAn example is an HDD 312 configured for custom housing electrical connections, referred to herein as HDD-CH (HDD-Custom Housing). The HDD-CH configuration utilizes a new end connector 315 for bus inputs to support connections from a separate main PCB housing the main controller / SOC (see example...). Figure 2 The main PCB 204's I / O is removed, and the HDD PCB (see example) is eliminated. Figure 3A (PCB 304). For example, circuitry such as actuator controllers (e.g., VCM, trimmer actuators), motor controllers (e.g., disk spindle motors), and sensors (e.g., temperature, rotational vibration, etc.) are internally moved to the HDD housing or may be placed on the main PCB 204. The housing for the spindle motor connector will be placed internally or using a jumper connection scheme that will be reconnected to connector 315.

[0034] Data storage system signal integrity

[0035] As discussed elsewhere in this paper, previously known methods for archiving storage platforms utilizing shared electronics rely on significantly large PCBs to serve data storage arrays, requiring long electrical transmit lengths (e.g., up to 300 mm) and potentially high-frequency electrical multiplexers. These requirements, in turn, may necessitate the use of low-loss, high-cost PCB laminates, for example, five times or more the cost of conventional PCB laminates. For instance, the fabrication of such low-loss dielectrics increases costs, and the large laminates require special pre-conditioning for heat dissipation due to the possibility of component misalignment. Furthermore, opportunities for electrical T-connectors with such long transmit lengths are limited, as electrical multiplexers are typically required in this context.

[0036] According to the implementation plan, by using the HDD (see example) Figure 2 The HDD 202) is stacked mechanically and electrically with the motherboard (see example). Figure 2 The main PCB 204 is used to reduce PCB interconnect losses. HDDs 202 are stacked one on top of the next (e.g., vertically stacked), and thus connected to the main PCB 204 via end connectors (at or near the vertical ends / rear ends of HDDs 202), achieving efficient electrical transmission line lengths. In other words, stacking HDDs 202 (e.g., rather than placing them all in an array above the main PCB) allows the main controller / SoC to be centrally positioned on the main PCB 204, minimizing the total electrical transmission line length between the HDDs 202 and the controller. According to the implementation, the controller is positioned on the main PCB 204 such that each electrical transmission line length between the respective HDD 202 and the controller is substantially equal (e.g., similar but not necessarily absolutely identical).

[0037] Figure 4A This is a schematic diagram illustrating a single-channel modular data storage system according to an implementation scheme. Figure 400 illustrates a 4×2 HDD 402 (or "HDDC" for an HDD assembly including head disk assembly (HDA) mechanical components and interposer connectors) configuration in which a single single-channel controller 406 is reasonably centered on the main PCB 404 such that (i.e., at a given rate corresponding to the single-channel controller 406) equal / nearly equal line lengths are provided between the groups of HDD 402. In the case of dual-channel controller 406 (e.g., costing approximately 1.5 times more than a single-channel controller) or two single-channel controllers 406, the system can operate at approximately twice the rate of a single controller 406.

[0038] exist Figure 4A The example configuration depicts a main PCB 404, which includes a multiplexer circuit 408 (“multiplexer” or simply “multiplexer 408”) and an electrical T-connector 409. The multiplexer circuit is located between a system controller circuit 406 (simply “controller 406”) and multiple groups of HDD storage devices 402 (simply “HDD 402”). The electrical T-connector is located between the multiplexer 408 and each pair of HDDs 402 in each group of storage devices. Continuing with the example of an 8x storage system, each group of HDDs 402 contains two groups (e.g., a first group and a second group) of four stacked (shown herein as vertically stacked) HDDs 402 (2×4 configuration). Therefore, the first multiplexer 408a is used to select the signal transmitted from the controller 406 and route the signal to each of the first and second packets; the second multiplexer 408b is used to select each of the signals transmitted from the first multiplexer 408a and route the signal to each of the two pairs in the first packet; and the third multiplexer 408c is used to select each of the signals transmitted from the first multiplexer 408a and route the signal to each of the two pairs in the second packet. Furthermore, the T-connector 409 is used to route each of the signals transmitted from each of the second multiplexer 408b and the third multiplexer 408c to each HDD 402 in each pair of the first and second packets.

[0039] With the controller 406 typically positioned centrally on the main PCB 404 (129mm × 230mm in this example) and between the mounted HDDs 402, and taking into account the vertical and horizontal gaps between the stacked HDDs 402, the transmission line length between the controller 406 and each HDD 402 in this example (via a series of multiplexers 408a-408c and T-connectors 409) is shown as approximately 90mm to 95mm (approximately 2mm to 5mm from the controller 406 to the first multiplexer 408a, plus approximately 88mm from the first multiplexer 408a through the corresponding multiplexers 408b, 408c to each HDD 402 (the top left HDD is shown in dashed lines). Therefore, at least in part, the symmetrical / balanced layout of the HDDs 402 enables the minimization of bus length (and associated interconnect losses) and the near-equalization of individual line (trace) lengths / paths. Therefore, for high-speed interfaces, signal integrity is significantly simplified, and for low-speed interfaces, shorter interconnects help meet timing requirements, meaning performance can be improved compared to alternative memory systems. Furthermore, and to reiterate, relatively low-cost minimum-layer PCB materials can be used in this paper, instead of the relatively high-cost low-loss PCB materials used in alternative systems. It should be noted that in the specific implementation utilizing a main PCB 404 with multiple controllers 406, even shorter trace lengths can be expected, as each controller 406 can be positioned closer to the corresponding group of HDDs 402 with which each controller 406 operates.

[0040] Figure 4B This is a schematic diagram illustrating a dual-channel modular data storage system according to an implementation scheme. Figure 410 illustrates a 4×2 HDD 402 configuration in which a single dual-channel controller 416 is reasonably centered on the main PCB 414 such that (i.e., at a given rate corresponding to the parallel channels of the dual-channel controller 416) equal / nearly equal line lengths are provided between the groups of HDD 402. Figure 4BThe example configuration depicts a main PCB 414 comprising multiple (one for each channel of controller 416) multiplexer circuits 408 and T-connectors 409. These multiplexer circuits are located between the dual-channel system controller circuit 416 (referred to as "controller 416") and multiple groups of HDDs 402. The T-connectors are located between each multiplexer 408 and each pair of HDDs 402 within each group. Continuing with the 8x storage system example herein, each group of HDDs 402 comprises two groups (e.g., a first group and a second group) of four stacked (shown herein as vertically stacked) HDDs 402 (2×4 configuration). Therefore, a first multiplexer 408a is used to select a signal transmitted from the first channel of controller 416 and route that signal to each of the first and second groups, and a second multiplexer 408b is used to select a signal transmitted from the second channel of controller 416 and route that signal to each of the first and second groups. From here, the T-connector 409 is used to route each of the signals transmitted from each of the first multiplexer 408a and the second multiplexer 408b to each HDD 402 in each pair of the first and second packets. Alternatively, multiplexers 408 may be implemented instead of the T-connector 409. Also, at least in part, the symmetrical / balanced layout of the HDDs 402 enables the minimization of bus length (and associated interconnect losses) and the substantially equal lengths / paths of the individual lines (traces) and the corresponding signal integrity benefits.

[0041] Storage device power management

[0042] Power large-scale integrated circuits (PLSIs) are power chips that control the two main movable components of an HDD (spindle motor and VCM). The System-on-a-Chip (SoC) (Master Drive Controller) sends control signals to the PLSI, which in turn controls the VCM movement and spindle motor speed. PLSIs are primarily analog and therefore are not integrated into digitally-based SoCs. In the context of the modular data storage system (HD-MM) architecture described in this paper, the placement of the PLSI depends on the configuration used, such as HDD-IC (...). Figure 3A ) or HDD-CH ( Figure 3B ).

[0043] Figure 5A This is a side view schematic diagram illustrating a modular data storage system with interpolator electrical connections according to an embodiment. According to the embodiment, in the scenario of an HDD configured in the form of an HDD-IC as described herein, each HDD 502 (see also...) Figure 2 HDD 202 Figure 3A HDD 302, Figures 4A to 4B The HDD 402 includes a corresponding PLSI 503 chip. Further, according to the implementation scheme, the main PCB 504 (see also...) Figure 2 Main PCB 204 Figures 4A to 4B The main PCB 404 also includes a PLSI 505 chip, which confines the power plane to the main PCB 504 area. In this paper, the actuator and spindle motor control signals from the PLSI 505 are not actually used, as the actuator and spindle motor control signals are dedicated to each PLSI 503 on each corresponding HDD 502. Regarding the EPO (Emergency Power Off) condition, the BEMF (Back Electromotive Force) can be provided by the PLSI 503 of the active HDD 502, while being routed to the PLSI 505 on the main PCB 504.

[0044] Figure 5B This is a side view schematic diagram illustrating a modular data storage system with customized housing electrical connections according to an embodiment. According to the embodiment, in the case of an HDD configured in the HDD-CH form as described herein, the main PCB 514 (see also...) Figure 2 Main PCB 204 Figures 4A to 4B The main PCB 404 includes a PLSI 515 chip, thereby confining the power plane to the main PCB 514 area. Herein, actuator and spindle motor control signals from the PLSI 515 chip (e.g., via multiplexer 518) are transmitted to each HDD 512. Alternatively, the main PCB 514 may include a corresponding PLSI 515 chip for each HDD 512. For the HDD-CH configuration, EPO is inherently handled. Therefore, in scenarios where only one PLSI 515 chip serves multiple HDDs 512, the PLSI 515 will operate as an active PLSI to obtain BEMF to provide the required power for the EPO process.

[0045] Intercalator connection between main PCB and HDD

[0046] Figure 6A This is a perspective view illustrating a modular data storage system with interpolator electrical connections according to an implementation scheme; Figure 6B This is an example based on the implementation plan. Figure 6A A perspective view of the electrical connections of a modular data storage system; and Figure 6C This is an example based on the implementation plan. Figure 6A A perspective view of the interpolator board of a modular data storage system. In the context of the modular data storage system (HD-MM) architecture described herein, each HDD 602 ​​(see also...) Figure 2 HDD 202 Figure 3A HDD 302, Figures 4A to 4B HDD 402 Figure 5A HDD 502, Figure 5B HDD 512) and main PCB 604 (see also) Figure 2 Main PCB 204 Figures 4A to 4B Main PCB 404 Figure 5A Main PCB 504 Figure 5B The electrical interconnects (and mechanical interconnects) between the main PCB 514, configured for electrical connection to one or more hosts via host connector 604a, are required for electrical transmission / communication (e.g., bus) purposes. For this connection purpose, interposer electrical connectors are employed according to the implementation.

[0047] Figure 7 This is a side view schematic illustrating a modular data storage system with interposer electrical connections according to an embodiment. The interposer connections include a board connector 607a electrically connected to a main PCB 604, an interposer board 607b electrically connected to the board connector 607a, and an HDD connector 607c electrically connected to an HDD 602. According to one embodiment, the interposer board 607b includes a solid board (e.g., a PCB). According to another embodiment, the interposer board 607b includes a flexible board (e.g., a flexible printed circuit or "FPC"). Furthermore, in... Figure 8 The table presents options for the appropriate type of electrical connector for each of the board connector 607a and HDD connector 607c.

[0048] Figure 8 This is a table illustrating interposer electrical connection options according to the implementation scheme. While such connection options are primarily applicable to HDD-ICs, these connection options, or related hybrid options, can be utilized in the form of HDD-CHs without a PCB 304 (see, for example...). Figure 6A Compared to the solid inserter plate 607b ( Figure 7 ()( Figure 8 The use of connectors 1 to 4, board connector 607a ( Figure 7 The following connector types can be selected: (i) edge connectors; (ii) standard board-to-board (B2B) connectors; (iii) floating B2B connectors; and (iv) crimp connectors. In this scenario, for edge connectors and standard B2B connectors, each HDD 602 ​​( Figures 6A to 6B , Figure 7 ) and main PCB 604 ( Figures 6A to 6C , Figure 7 The alignment between them should have higher precision because the positioning margin for the connector mating is smaller. Similarly, compared to the use of the flexible inserter board 607b ( Figure 8For connectors 5, 6, and 8, board connector 607a can be selected from the group consisting of the following connector types: (ii) standard B2B connectors; (iii) floating B2B connectors; and (iv) crimp connectors. In this document, also for standard B2B connectors, the alignment between each HDD 602 ​​and the main PCB 604 should have higher precision due to the smaller positioning margin for the connector mating. Furthermore, compared to flexible insert board 607b (… Figure 8 In the use of connector 607a (number 7), board connector 607a can be a board-to-board (B2F) flexible connector. In this scenario, for the B2F connector, the alignment between each HDD 602 ​​and the main PCB 604 can be relaxed for connector mating, compared to the aforementioned scenario. In the aforementioned connector implementation (… Figure 8 In specific implementations of each connector (numbers 1 to 8), according to the implementation scheme, a standard B2B connector is used for HDD connector 607c ( Figure 6C , Figure 7 Finally, regarding the use of the flexible interposer board 607b and the B2F HDD connector 607c ( Figure 8 For board connectors 607a (numbers 9 through 12), the board connector can be selected from the group consisting of the following connector types: (i) board edge connector; (ii) standard board-to-board (B2B) connector; (iii) B2F connector; and (iv) crimp connector.

[0049] According to the implementation described herein for a data storage system based on modular hard disk drives, most of the unique HDD components are retained on each drive, while other electronics (depending on the implementation, particularly the controller and associated circuitry, and including the host connector, DRAM, etc.) are moved to a shared main PCB. By stacking the HDDs to connect to the motherboard mechanically and electrically, PCB interconnect losses are reduced, resulting in efficient electrical PCB transmission line lengths. In other words, stacking the HDDs instead of placing them all in an array on top of the main PCB allows the main controller / SoC to be centrally positioned on the main PCB, minimizing the total electrical transmission line length between the HDD 202 and the controller.

[0050] Hard drive configuration

[0051] As discussed, the implementation scheme can be used in scenarios employing multiple data storage devices (DSDs) (including hard disk drives (HDDs)). Therefore, according to the implementation scheme, Figure 1A plan view illustrating a typical HDD 100 is shown to illustrate exemplary operating components. However, HDDCs (e.g., HDA mechanisms and interpolators with some but fewer electronics than typical ones) (such as HDD-IC and / or HDD-CH as described herein) are preferred candidates for the HD-MM modular storage system architecture / platform described herein.

[0052] Figure 1 The functional arrangement of components of an HDD 100, including a slider 110b, is illustrated. The slider includes a magnetic read / write head 110a. The slider 110b and head 110a may be collectively referred to as the head slider. The HDD 100 includes at least one head gimbal assembly (HGA) 110 with the head slider, a lead suspension 110c typically attached to the head slider via a bend, 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 (also 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 can be attached to the spindle 124 using a disk clip 128.

[0053] HDD 100 also includes an arm 132 attached to HGA 110, a carriage 134, and a voice coil motor (VCM) including an armature 136 and a stator 144. The armature includes a voice coil 140 attached to the carriage 134, and the rotor includes a voice coil magnet (not visible). The armature 136 of the VCM is attached to the carriage 134 and configured to move the arm 132 and HGA 110 to access the portion of media 120, which are collectively mounted on a pivot shaft 148 having an inserted pivot bearing assembly 152. In the case of an HDD with multiple disks, the carriage 134 may be referred to as an "E-block" or comb because the carriage is arranged to carry a linked array of arms, thus giving it a comb-like appearance.

[0054] An assembly including a head universal joint assembly (e.g., HGA 110) with a bend to which the head slider is coupled, an actuator arm (e.g., arm 132) and / or load beam to which the bend is coupled, and an actuator (e.g., VCM) to which the actuator arm is coupled, can be collectively referred to as a head stack assembly (HSA). However, an HSA may include more or fewer components than those described above. For example, an HSA may refer to an assembly that also includes electrical interconnect components. Generally, an HSA is an assembly configured to move the head slider to access portions of the medium 120 for read and write operations.

[0055] Further reference Figure 1Electrical signals, including write signals to and read signals from the magnetic head 110a (e.g., current to the voice coil 140 of the VCM), are transmitted by a flexible cable assembly (FCA) 156 (or “flexible cable”, or “flexible printed circuit”). The interconnect between the flexible cable 156 and the magnetic head 110a may include an arm electronics (AE) module 160, which may have an onboard preamplifier for the read signal and other read and write channel electronics. The AE module 160 may be attached to a carriage 134, as shown. The flexible cable 156 may be coupled to an electrical connector block 164, which in some configurations provides electrical communication via an electrical feedthrough provided by the HDD housing 168. The HDD housing 168 (or “housing base”, “substrate”, or simply “base”) together with the HDD cover provides a semi-sealed (or hermetically sealed, in some configurations) protective enclosure for the information storage components of the HDD 100.

[0056] Other electronic components, including the disk controller and servo electronics including a digital signal processor (DSP), provide electrical signals to the drive motor, the voice coil 140 of the VCM, and the magnetic head 110a of the HGA 110. The electrical signals provided to the drive motor cause it to rotate, thereby providing torque to the spindle 124, which is then transmitted to the medium 120 attached to the spindle 124. The medium 120 thus 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 is mounted, allowing the slider 110b to fly above the surface of the medium 120 without contacting the thin magnetic recording layer on which information is recorded. Similarly, in HDDs utilizing gases lighter than air (such as helium used in a non-limiting example), the rotating medium 120 forms an air cushion that acts as a gas or fluid bearing on which the slider 110b is mounted.

[0057] The electrical signal supplied 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 recorded. Therefore, the armature 136 of the VCM swings through an arc 180, allowing the head 110a of the HGA 110 to access the individual tracks on the medium 120. Information is stored in multiple radially nested tracks on the medium 120, which are arranged in sectors (such as sector 184) on the medium 120. Accordingly, each track is composed of multiple sectorized track portions (each sectorized track portion may also be referred to as a "track sector") such as sectorized track portion 188. Each sectorized track portion 188 may include recorded information and a data header containing error correction code information and a servo burst signal pattern, such as the ABCD-servo burst signal pattern (which is information identifying track 176). When accessing track 176, the read element of the head 110a of the HGA 110 reads a servo burst signal pattern, which provides a positioning error signal (PES) to the servo electronics. This controls the electrical signal supplied to the voice coil 140 of the VCM, enabling the head 110a to follow track 176. Upon locating track 176 and identifying a specific sectored track portion 188, the head 110a either reads information from track 176 or writes information to track 176 according to instructions received by the disk controller from an external agent (e.g., the microprocessor of a computer system).

[0058] The electronic architecture of an HDD includes multiple electronic components for performing its respective HDD operating functions, such as a hard disk controller (HDC), interface controller, arm electronics module, data channel, motor driver, servo processor, buffer memory, etc. Some (but not all) of these components may be included as part of the HDDC described herein. Two or more of these components may be combined on a single integrated circuit board known as a “System-on-a-Chip” (“SOC”). Several (if not all) of these electronic components are typically arranged on a printed circuit board attached to the bottom side of the HDD, such as to the HDD housing 168.

[0059] This article references hard drives, such as references Figure 1The illustrated and described HDD 100 may include an information storage device sometimes referred to as a “hybrid drive.” A hybrid drive generally refers to a storage device that combines the functionality of a conventional HDD (see, for example, HDD 100) with a solid-state storage device (SSD) that uses non-volatile memory (such as flash memory or other solid-state (e.g., integrated circuit) memory) that is electrically erasable and programmable. Because the operation, management, and control of different types of storage media typically differ, the solid-state portion of a hybrid drive may include its own corresponding controller functionality, which may be integrated with the HDD functionality into a single controller. Hybrid drives can be built and configured to operate and utilize the solid-state portion in a variety of ways, such as, by way of non-limiting example, using the solid-state memory as cache memory for storing frequently accessed data, for storing I / O-intensive data, etc. Additionally, hybrid drives can be built and configured essentially as two storage devices, namely a conventional HDD and an SSD, in a single housing, with one or more interfaces for host connectivity.

[0060] Extensions and alternatives

[0061] In the foregoing description, embodiments of the invention have been described with reference to numerous specific details, which may vary depending on the specific implementation. Therefore, various modifications and changes can be made without departing from the broad spirit and scope of the embodiments. Accordingly, the invention, and the applicant's intended sole and exclusive indicator of the invention, is the set of claims in the specific form issued by this patent application, including any subsequent amendments. Any definitions of terms expressly set forth herein that are included in these claims shall determine the meaning of those terms as used in the claims. Therefore, any limitations, elements, characteristics, features, advantages, or attributes not expressly cited in the claims shall not in any way limit the scope of the claims. Therefore, this specification and the drawings are to be considered illustrative rather than restrictive.

[0062] Furthermore, in this description, certain process steps may be shown in a specific order, and alphanumeric labels may be used to identify certain steps. Unless explicitly specified in the specification, the implementation is not necessarily limited to any particular order in which such steps are performed. Specifically, these labels are used only for the convenience of identifying the steps and are not intended to specify or require a particular order in which such steps are performed.

Claims

1. A data storage system, the data storage system comprising: a main printed circuit board (PCB) including at least one system controller circuit; and a plurality of stacked storage devices each mechanically and electrically connected with the main PCB at or near a longitudinal end of the storage device; wherein the system controller circuit is centrally positioned on the main PCB such that a total electrical transmission line length between the plurality of storage devices and the system controller circuit is minimized.

2. The data storage system of claim 1, wherein the system controller circuit is positioned on the main PCB such that each electrical transmission line length between a respective storage device and the system controller circuit is substantially equal.

3. The data storage system of claim 1, wherein the plurality of storage devices includes a plurality of hard disk drives (HDDs).

4. The data storage system of claim 1, wherein: the system controller circuit includes a single channel circuit; and the main PCB includes: a multiplexer circuit between the system controller circuit and at least two groupings of the storage devices; and a T-connector between the multiplexer circuit and each pair of storage devices in each grouping of storage devices.

5. The data storage system of claim 1, wherein the system controller circuit includes a dual channel circuit.

6. The data storage system of claim 5, wherein the main PCB includes: a first multiplexer circuit between one channel of the system controller circuit and at least one first set of the storage devices; and a second multiplexer circuit between another channel of the system controller circuit and at least one second set of the storage devices.

7. The data storage system of claim 6, wherein the main PCB further includes: a first T-connector between the first multiplexer circuit and one pair of the first set of storage devices; and a second T-connector between the first multiplexer circuit and another pair of the first set of storage devices.

8. The data storage system of claim 1, wherein: the plurality of storage devices includes a plurality of hard disk drives (HDDs) each including: a plurality of disk media rotatably mounted on a motor spindle, a plurality of head sliders each housing a read-write transducer configured to read from and write to a disk media of the plurality of disk media, one or more actuators configured for moving the head slider to access portions of the disk media; and electronics including a preamplifier, an actuator controller, a motor controller, and a sensor circuit; and the plurality of HDDs are configured to be operated in a RAID configuration. The main PCB further includes power large scale integration (PLSI) circuitry configured to send signals to the electronics of each HDD through multiplexers on the main PCB.

9. The data storage system of claim 1, wherein: The plurality of storage devices includes a plurality of hard disk drives (HDDs), each HDD including: a plurality of disk media rotatably mounted on motor spindles, a plurality of head sliders each housing a read-write transducer configured to read from and write to a disk media of the plurality of disk media, one or more actuators configured to move the head sliders to access portions of the disk media; and electronics including power large scale integration (PLSI) circuitry, preamplifiers, actuator controllers, motor controllers, and sensor circuitry.

10. The data storage system of claim 1, wherein the main PCB further includes a plurality of independent system controller circuitries each configured to operate with a corresponding logical unit of memory corresponding to the plurality of storage devices.

11. The data storage system of claim 1, further comprising: a plurality of solid state interposer circuit boards each configured to electrically connect a corresponding connector of the main board with a corresponding board-to-board connector of a storage device of the plurality of storage devices; wherein each main board connector is one of a group consisting of a board edge connector, a non-floating board-to-board connector, a floating board-to-board connector, and a crimped connector.

12. The data storage system of claim 1, further comprising: a plurality of flexible interposer circuit boards each configured to electrically connect a corresponding connector of the main board with a corresponding board-to-board connector of a storage device of the plurality of storage devices; wherein each main board connector is one of a group consisting of a board-to-flexible connector, a non-floating board-to-board connector, a floating board-to-board connector, and a crimped connector.

13. The data storage system of claim 1, further comprising: a plurality of flexible interposer circuit boards each configured to electrically connect a corresponding connector of the main board with a corresponding board-to-flexible connector of a storage device of the plurality of storage devices; wherein each main board connector is one of a group consisting of a board-to-flexible connector, a non-floating board-to-board connector, a floating board-to-board connector, and a crimped connector.

14. A data storage system, comprising: a main printed circuit board (PCB) including at least one system controller circuitry; and a plurality of stacked hard disk drives (HDDs) each mechanically and electrically connected with the main PCB at or near a longitudinal end of the HDD; The system controller circuit is positioned on the main PCB such that each electrical transmission line between the corresponding HDD and the system controller circuit is substantially the same length.

15. The data storage system according to claim 14, wherein: The plurality of HDDs includes a first group of four stacked HDDs connected to one lateral side of the main PCB and a second group of four stacked HDDs connected to the other lateral side of the main PCB; and Each electrical transmission line between the corresponding HDD and the system controller circuit is less than 100 millimeters (mm) in length.

16. The data storage system according to claim 15, wherein: The system controller circuit includes a single-channel circuit; and The main PCB includes: A first multiplexer circuit is located between the system controller circuit and the first and second packets of the HDD; A plurality of second multiplexer circuits, the plurality of second multiplexer circuits being located between the first multiplexer circuit and each of the first and second packets of the HDD; and T-connectors are located between each second multiplexer circuit and a pair of HDDs in each of the first and second groups of the HDD.

17. The data storage system according to claim 14, wherein: The plurality of HDDs includes a first group of four stacked HDDs connected to one lateral side of the main PCB and a second group of four stacked HDDs connected to the other lateral side of the main PCB; The system controller circuit includes a dual-channel circuit. and The main PCB includes: A first multiplexer circuit is located between a first channel of the system controller circuit and the first group of the HDD. A second multiplexer circuit is located between the second channel of the system controller circuit and the second group of the HDD; The first T-connector is located between the first multiplexer circuit and the first pair in the first group of the HDD; The second T-connector is located between the first multiplexer circuit and the first pair in the second group of the HDD; A third T-connector, located between the second multiplexer circuit and the second pair in the first group of the HDD; and A fourth T-connector is located between the second multiplexer circuit and the second pair in the second group of the HDD.

18. The data storage system according to claim 14, wherein: Each of the plurality of HDDs includes: Multiple disk media, the multiple disk media being rotatably mounted on a motor spindle, Multiple read / write head sliders, each accommodating a read / write transducer configured to read from and write to the plurality of disk media. An actuator system configured to move the plurality of head sliders to access portions of the disk medium; and Electronic devices, including a preamplifier, an actuator controller, a motor controller, and sensor circuitry; and The main PCB also includes a power large-scale integration (PLSI) circuit configured to send signals to at least a portion of the electronics of each HDD via a multiplexer on the main PCB.

19. The data storage system according to claim 14, wherein: Each of the plurality of HDDs includes: Multiple disk media, the multiple disk media being rotatably mounted on a motor spindle, A means for accommodating a read / write transducer configured to read from and write to one of the plurality of disk media. A means for moving the read / write transducer to access portions of the disk medium; and Electronic devices, including power large-scale integrated circuits (PLSI), preamplifiers, actuator controllers, motor controllers, and sensor circuits.

20. A data storage system, the data storage system comprising: A main printed circuit board (PCB) including at least one system controller circuit; and Multiple stacked hard disk drives (HDDs), each HDD being mechanically and electrically connected to the main PCB at or near its longitudinal end, wherein each HDD comprises: A disk medium, which is rotatably mounted on a motor spindle. A means for storing data by reading from and writing to the disk medium. means for moving the device for storage to access portions of the disk medium; and Electronic devices, including a preamplifier, an actuator controller, a motor controller, and sensor circuitry; The system controller circuit is positioned on the main PCB such that the length of each electrical transmission line between the corresponding HDD and the system controller circuit is minimized.

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