In-situ installation of quadrature flux magnet in voice coil motor actuator

Abstract

A method of assembling a voice coil motor (VCM), such as for a hard disk drive, includes: forming an opening in a yoke; attaching a main magnet to an inner surface of the yoke; mounting a quadrature flux magnet into the channel of the main magnet through an opening in the yoke; and mounting the plug into the opening in the yoke. Thus, the number of components is minimized, and the manufacturing process is easily incorporated into existing VCM manufacturing processes.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Non-Provisional Application No. 18 / 224,398, filed in the U.S. Patent and Trademark Office on July 20, 2023, entitled “IN-SITU INSTALL OF CROSS-FLUX MAGNET IN VOICE COILMOTOR ACTUATOR,” and the entire contents of that U.S. Non-Provisional Application are incorporated herein by reference for all purposes, and claims priority to U.S. Provisional Application No. 63 / 435,405, filed on December 27, 2022. Technical Field

[0003] Embodiments of the present invention relate generally to voice coil motors, and particularly to hard disk drive rotary voice coil actuators having orthogonal flux magnets mounted through a main magnet housing. Background Art

[0004] A hard disk drive (HDD) is a non-volatile storage device that is housed in a protective housing and stores digitally encoded data on one or more circular disks with magnetic surfaces. When the 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 in a slider that is positioned above 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 operates using an electric current flowing through its coil, thereby generating a magnetic field. Electrical pulses are sent to the write head in different patterns of positive and negative currents. The current in the coil of the write head generates a local magnetic field in the gap between the head and the magnetic recording disk, which in turn magnetizes a small area on the recording medium.

[0005] A voice coil motor ("VCM") is a type of actuator typically employed in HDDs to move the read / write heads to access portions of the corresponding magnetic recording disks for read and write operations. A VCM relies on permanent magnets to achieve its own persistent magnetic field. This field is typically strongest at the surface of the magnet and decreases with distance from it, so the magnetic flux density also decreases with distance from the magnet. In addition, the cost of permanent magnets is typically relative to the corresponding grade of the magnet and the material from which the magnet is made, with higher grades indicating stronger magnets. Increasing areal density (a measure of the number of bits of information that can be stored on a given area of ​​the disk surface) is one of the continuing goals of the evolution of hard disk drive technology. Given the trend towards higher and higher areal density in HDDs, performance improvements in VCMs might be expected.

[0006] Any approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any approaches described in this section qualify as prior art merely by virtue of their inclusion in this section. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Embodiments are illustrated by way of example and not limitation in the accompanying drawings in which like reference numerals refer to similar elements and in which:

[0008] Figure 1 is a plan view illustrating a hard disk drive (HDD) according to an embodiment;

[0009] Figure 2 is a perspective view illustrating a modified voice coil motor (VCM) assembly having a cross-traffic magnet according to one embodiment;

[0010] Figure 3A is an example according to one embodiment Figure 2 A perspective view of a half assembly of a modified VCM assembly;

[0011] Figure 3B According to an implementation scheme Figure 3A A front view of a half assembly of a modified VCM assembly;

[0012] Figure 3C According to an implementation scheme Figure 3A A top view of a half assembly of a modified VCM assembly;

[0013] Figure 3D According to an implementation scheme Figure 3A A bottom view of a half assembly of a modified VCM assembly;

[0014] Figure 4A is an example of a method for Figure 3A A perspective view of a first stage of the assembly process of a half assembly of a modified VCM assembly;

[0015] Figure 4B is an example of a method for Figure 3A A perspective view of a second stage of the assembly process of a half assembly of a modified VCM assembly;

[0016] Figure 4C is an example of a method for Figure 3A A perspective view of a third stage of the assembly process of a half assembly of a modified VCM assembly;

[0017] Figure 4D is an example of a method for Figure 3AA perspective view of a fourth stage of the assembly process of a half assembly of a modified VCM assembly;

[0018] Figure 4E is an example of a method for Figure 3A A bottom perspective view of a fourth stage of the assembly process of a half assembly of a modified VCM assembly;

[0019] Figure 4F is an example of a method for Figure 3A a perspective view of a fifth stage of the assembly process of the half assembly of the modified VCM assembly; and

[0020] Figure 5 is a flow chart illustrating a method of assembling a VCM assembly having orthogonal traffic magnets according to one embodiment. DETAILED DESCRIPTION

[0021] Generally, methods of a modified voice coil motor (VCM) assembly having a orthogonal flux magnet, such as for use in a hard disk drive (HDD), are described. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the embodiments of the invention described herein. However, it will be apparent that the embodiments of the invention described herein can be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form in order to avoid unnecessarily obscuring the embodiments of the invention described herein.

[0022] introduction

[0023] the term

[0024] Reference herein to "an embodiment," "one embodiment," etc., is intended to mean that a particular feature, structure, or characteristic being described is included in at least one embodiment of the present invention. However, instances of such phrases are not necessarily all referring to the same embodiment.

[0025] The term "substantially" should be understood to describe a feature that is mostly or nearly structured, constructed, dimensioned, etc., but in practice manufacturing tolerances, etc. cause the structure, configuration, dimensions, etc. not always or necessarily to be exactly as described. For example, describing a structure as "substantially vertical" would give the term its ordinary meaning, such that the sidewalls are vertical for all practical purposes, but may not be exactly at 90 degrees throughout.

[0026] While terms such as "best," "optimize," "minimum," "minimize," "maximum," "maximize," etc. may not have certain values ​​associated with them, if such terms are used herein, it is intended that one of ordinary skill in the art will understand that such terms will include affecting values, parameters, metrics, etc. in beneficial directions consistent with the present disclosure as a whole. For example, describing a value of something as "minimum" does not require that the value actually equal some theoretical minimum value (e.g., zero), but should be understood in a practical sense that the corresponding goal is to move the value in a beneficial direction toward the theoretical minimum value.

[0027] Scenario

[0028] Recall that it may be desirable to observe performance improvements in VCMs. The torque produced in a VCM is proportional to the magnetic flux density produced by the corresponding permanent magnets, because as the magnetic flux density increases, the motor efficiency also increases. Therefore, the higher the magnetic field gradient produced by the permanent magnets, the more efficiently the VCM may perform. However, because the space of HDDs is very limited, the available methods for building better VCMs are also limited.

[0029] HALBACH voice coil motor with opening installed

[0030] Figure 2 2 is a perspective view illustrating a modified voice coil motor (VCM) assembly with a orthogonal flux magnet according to one embodiment. The VCM assembly 200 ("VCM 200") includes a first magnet assembly 202a and a second magnet assembly 202b coupled together. For example, the first main magnet assembly 202a and the second main magnet assembly 202b may be combined together or may be manufactured as an integrated assembly.

[0031] The first magnet assembly 202a includes a first main permanent magnet 204a, which is magnetized to have a magnetic north pole 204a-n (N) and an adjacent magnetic south pole 204a-s (S) on the respective sides of the first boundary, and is coupled to a corresponding first yoke 206a. The first yoke 206a includes an opening 206a-o passing therethrough, which is filled with a first plug 206a-p. According to one embodiment, the first yoke 206a and the first plug 206a-p are composed of the same material, such as, for example, stainless steel. It is noteworthy that the first magnet assembly 202a also includes a first orthogonal traffic magnet 205a, which is embedded in the first main magnet 204a through the opening 206a-o in the first yoke 206a and coupled to the first main magnet. According to an embodiment, the first orthogonal traffic magnet 205a is embedded in a pre-formed channel or groove in the first main magnet 204a (see, for example FIG. 4B to FIG. 4C), extending from the proximal side (yoke 206a side) or surface of the first main magnet 204a toward the distal side (air gap side) or surface but not to the distal side (air gap side) or surface, and extending from the front side or surface of the first main magnet 204a to the rear side or surface. The first orthogonal flux magnet 205a is magnetized in a direction substantially orthogonal (i.e., perpendicular) to the direction of the N / S poles 204a-n, 204a-s (here, for example, in the direction from N to S), thereby forming a so-called Halbach array. In general, a Halbach array is a special arrangement of permanent magnets that enhances the magnetic field (e.g., enhances the flux) on one side of the array while canceling the field (e.g., canceling the flux) to near zero on the other side by having a spatially rotating magnetization pattern.

[0032] Here, the Halbach array effect is achieved by an embedded and appropriately magnetized first orthogonal traffic magnet 205a, which is embedded within and between the N / S poles 204a-n, 204a-s (i.e., substantially at the first boundary between the N / S poles). This arrangement and in-situ assembly technique is achieved by using openings 206a-o through the first yoke 206a, through which the first orthogonal traffic magnet 205a is inserted into the first main magnet 204a and the opening is filled with the first plug 206a-p, which produces a modification of the classic Halbach array that requires fewer total parts (compared to composite magnets or other forms of Halbach array assemblies manufactured outside the first magnet assembly 202a) and significantly reduces manufacturing complexity at the expense of a small amount of optimality.

[0033] Similarly, the second magnet assembly 202b includes a second main permanent magnet 204b that is magnetized to have a magnetic north pole 204b-n (N) and an adjacent magnetic south pole 204b-s (S) on respective sides of the second boundary and is coupled to a corresponding second magnetic yoke 206b. The second magnetic yoke 206b includes an opening 206b-o therethrough (not visible here; see e.g. Figure 4A ), which is filled with a second plug 206b-p (not visible here; see e.g. Figure 3D , Figure 4F According to one embodiment, the second yoke 206b and the second plug 206b-p are composed of the same material, such as, for example, stainless steel.

[0034] The second magnet assembly 202b also includes a second orthogonal flux magnet 205b that is embedded in the second main magnet 204b through an opening 206b-o in the second yoke 206b and is coupled to the second main magnet. According to an embodiment, the second orthogonal flux magnet 205b is embedded in a pre-formed channel or groove in the second main magnet 204b (see, e.g., FIG. 4B to FIG. 4C The second main magnet 204b is provided with a channel 204b-c), extending from the proximal side (yoke 206b side) or surface of the second main magnet 204b toward the distal side (air gap side) or surface but not to the distal side (air gap side) or surface, and extending from the front side or surface of the second main magnet 204b to the rear side or surface. The second orthogonal traffic magnet 205b is magnetized in a direction substantially orthogonal to the direction of the N / S poles 204b-n, 204b-s (here, for example, in the direction from S to N), thereby forming a Halbach array. Here, the Halbach array effect is also achieved by the embedded and appropriately magnetized second orthogonal traffic magnet 205b, which is embedded in and between the N / S poles 204b-n, 204b-s (i.e., substantially at the first boundary between the N / S poles), and requires fewer overall components and reduced manufacturing complexity.

[0035] Note that while the first main magnet 204a and the second main magnet 204b are depicted here and throughout as having portions magnetized in a particular direction (i.e., N / S poles 204a-n, 204a-s and N / S poles 204b-n, 204b-s) for purposes of illustration, the direction in which each pole 204a-n, 204a-s, 204b-n, 204b-s is magnetized may vary depending on the specific implementation. For example, the poles depicted as poles 204a-n and 204b-n may actually be magnetized in the S direction, while the poles depicted as poles 204a-s and 204b-s may actually be magnetized in the N direction. Similarly, while for purposes of illustration, the first and second orthogonal traffic magnets 205a, 205b are depicted as being magnetized in a particular direction, the direction in which each orthogonal traffic magnet 205a, 205b is magnetized may vary from implementation to implementation, and thus, each may be magnetized in a direction opposite to that depicted herein, provided that each is magnetized in a direction substantially orthogonal to the direction of the N / S poles 204a-n, 204a-s, 204b-n, 204b-s. In addition, a complete VCM assembly may be implemented with only one half assembly (e.g., magnet assembly 202a or 202b) configured in a Halbach array arrangement with a corresponding embedded orthogonal traffic magnet (e.g., orthogonal traffic magnet 205a or 205b), while the opposing cooperating VCM half assembly is configured conventionally, i.e., without a Halbach array arrangement with an embedded orthogonal traffic magnet.

[0036] Figure 3A is an example Figure 2 A perspective view of a half assembly of a modified VCM assembly, Figure 3B yes Figure 3A Front view of the modified VCM assembly half assembly, Figure 3C yes Figure 3A A top view of the half assembly of the modified VCM assembly, and Figure 3D yes Figure 3A Bottom view of a half assembly of a modified VCM assembly, all of which are according to one embodiment. As previously described, FIG. 3A to FIG. 3D yes Figure 2 200b) to further illustrate the details of the second magnet assembly 202b. According to one embodiment, multiple half assemblies can be manufactured in this same form and then coupled with another such half assembly to form a VCM magnet assembly (such as VCM assembly 200( Figure 2 )).

[0037] Collectively, FIG. 3A to FIG. 3DA second magnet assembly 202b is illustrated, which includes a second main permanent magnet 204b that is magnetized to have a magnetic north pole 204b-n (N) and an adjacent magnetic south pole 204b-s (S) on respective sides of a boundary 207, and is adhered or otherwise bonded to a corresponding second magnetic yoke 206b. The second magnetic yoke 206b includes an opening 206b-o therethrough (not visible here; see, e.g. Figure 4A ), which is filled with a second plug 206b-p ( Figure 3D Also shown is a second orthogonal flux magnet 205b ( FIG. 3A to FIG. 3B ). The second orthogonal flux magnet 205b is magnetized in a direction substantially orthogonal to the direction of the N / S poles 204b-n, 204b-s (here, for example, in a direction from S to N), thereby forming a Halbach array. As with the rotating VCM, the yoke 206b and the main permanent magnet 204b are configured in an annular shape, wherein different N / S poles of the main permanent magnet 204b are positioned relative to each other in the circumferential direction and are polarized in a direction substantially orthogonal to the main surface of the main permanent magnet 204b.

[0038] Method of assembling a VCM assembly having a cross-traffic magnet

[0039] 4A to 4F They are respectively exemplified according to one embodiment for Figure 3A A perspective view of stages of the assembly process of the half assemblies of the modified VCM assembly. In particular, Figure 4A is an example for Figure 3A A perspective view of a first stage of the assembly process of a half assembly of a modified VCM assembly; Figure 4B is an example for Figure 3A A perspective view of a second stage of the assembly process of a half assembly of a modified VCM assembly; Figure 4C is an example for Figure 3A A perspective view of a third stage of the assembly process of a half assembly of a modified VCM assembly; Figure 4D is an example for Figure 3A A perspective view of a fourth stage of the assembly process of a half assembly of a modified VCM assembly; Figure 4E is an example for Figure 3A a bottom perspective view of a fourth stage of the assembly process of the half assembly of the modified VCM assembly; and Figure 4F is an example for Figure 3A A perspective view of a fifth stage of the assembly process of a half assembly of a modified VCM assembly, all according to one embodiment.

[0040] Figure 5is a flow chart illustrating a method of assembling a VCM assembly having a cross-traffic magnet according to one embodiment. 4A to 4F The assembly phase describes Figure 5 A method for mounting an opening half assembly of a VCM assembly having a positive flow magnet, such as Figure 3A A half assembly of a modified VCM assembly.

[0041] Figure 4A The first stage of illustrative embodiment depicts a yoke 206b, such as a stamped plate, having openings 206b-o therethrough. Figure 4B The second stage depicts an uncharged primary magnet 204b bonded, adhered, attached or otherwise coupled to a yoke 206b, wherein the primary magnet 204b has grooves or channels 204b-c grounded or otherwise formed therein at a boundary 207. Figure 4C The third stage depicts the main magnet 204b being coupled to the yoke 206b, wherein the magnet 204b is now magnetized, charged, polarized, or otherwise configured with N / S poles 204b-n, 204b-s. Consistent with current typical manufacturing processes, the main magnet 204b is magnetized after being coupled to the yoke 206b, thus incorporating this process stage into the existing manufacturing process.

[0042] Figure 4D The fourth stage of FIG. 2 depicts the main magnet 204b coupled to the yoke 206b, wherein the orthogonal traffic magnet 205b is now installed, embedded within the main magnet 204b. According to one embodiment, the orthogonal traffic magnet 205b is pre-charged or pre-magnetized before being installed into the main magnet 204b. It is noteworthy that the orthogonal traffic magnet 205b is embedded within the channel 204b-c ( FIG. 4B to FIG. 4C ) and through the opening 206b-o in the yoke 206b ( Figure 4A ) is coupled to the main magnet 204b. According to one embodiment, the orthogonal traffic magnet 205b is embedded in the pre-formed channel 204b-c so that the orthogonal traffic magnet 205b extends from the proximal side (yoke 206b side) or surface of the main magnet 204b (e.g., coplanar with the main magnet 204b on the proximal side so as to be more like a traditional Halbach array) toward the distal side (air gap side) or surface but not to the distal side or surface, and extends from the front side or surface of the main magnet 204b to the back side or surface (see, e.g. Figure 4E). The portion of the main magnet 204b between the orthogonal traffic magnet 205b and the top surface of the main magnet 204b provides a single-piece main magnet 204b, thereby limiting the number of components and simplifying manufacturing. As described elsewhere herein, the second orthogonal traffic magnet 205b is magnetized in a direction substantially perpendicular to the direction of the N / S poles 204b-n, 204b-s (here, for example, in the direction from S to N), thereby effectively forming a Halbach array. Note that although for the purpose of illustration, the orthogonal traffic magnet 205b and the channels 204b-c in which the orthogonal traffic magnet 205b is embedded are each depicted as being generally rectangular in shape here and throughout the text, the formation shape of the orthogonal traffic magnet 205b and the corresponding channels 204b-c may vary with the specific implementation. For non-limiting example, the orthogonal traffic magnet 205b and corresponding channels 204b-c may be formed into a more trapezoidal shape whereby their respective sidewalls are tapered / chamfered (eg, wider on the proximal side and narrower on the distal side) to facilitate installation.

[0043] Figure 4E Illustrated Figure 4D A bottom perspective view of the fourth stage, again depicting the main magnet 204b coupled to the yoke 206b with the orthogonal flux magnet 205b mounted therein. Figure 4E Also illustrated are openings 206b-o in the yoke 206b through which the orthogonal flux magnet 205b is mounted into and between the N / S poles 204b-n, 204b-s of the main magnet 204b. Figure 4F The fifth stage depicts FIG. 4D to FIG. 4E configuration, and further having a plug 206b-p ( Figure 4E ), wherein the use of plugs 206b-p provides the desired substantially uninterrupted flux path for the yoke 206b.

[0044] Reference now Figure 5 At block 502, an opening is created in the yoke. For example, machining or other common manufacturing techniques are used to form openings 206b-o in the source yoke 206b (see, e.g., Figure 4A ).

[0045] At block 504, a main magnet is attached to the inner surface of the yoke. For example, the main magnet 204b is attached to the inner surface of the yoke 206b (see, e.g., Figure 4B According to one embodiment, before attaching the main magnet 204b, a channel 204b-c having a shape consistent with the orthogonal traffic magnet 205b is formed in the main magnet 204b ( FIG. 4B to FIG. 4C ). However, the channels 204b-c may alternatively be formed in situ after the main magnet 204b is coupled to the yoke 206b.

[0046] At block 506, the orthogonal traffic magnet is installed into the channel of the main magnet through the opening in the yoke. For example, the orthogonal traffic magnet 205b ( FIG. 4D to FIG. 4F ) is mounted to the channel 204b-c of the main magnet 204b ( FIG. 4B to FIG. 4C According to one embodiment, after attaching the main magnet (block 504) and before installing the orthogonal traffic magnet (block 506), the main magnet 204b is charged to provide a charge on the respective sides or portions of the main magnet (i.e., the N / S poles 204b-n, 204b-s, such as the boundary 207 (depicted between the poles 204b-n, 204b-s) Figure 4B According to one embodiment, before being installed in the main magnet 204b, the orthogonal flux magnet 205b is charged to set the magnetization direction to be substantially orthogonal to the magnetization direction of the main magnet 204b.

[0047] At block 508, a plug is installed into the opening in the yoke. For example, a stainless steel plug 206b-p ( Figure 4F ) is mounted into the opening 206b-o in the stainless steel yoke 206b. In addition to stainless steel, different iron alloy materials can also be implemented, however, it is preferred to use the same material for the plugs 206b-p and the yoke 206b.

[0048] The classic Halbach array requires a minimum of three magnetic components, each of which is pre-magnetized, to be assembled together and bonded while applying forces to each other. This presents a challenging process given the size and strength of the magnets used in the HDD VCM. In general, the methods described herein are improved over conventional HDD VCMs primarily in terms of VCM magnetic field strength and the total amount of magnetic material required. In addition, fewer total components are used and the manufacturing process is easily incorporated into the existing VCM manufacturing process, wherein such ease of manufacturing can result in a greater cost advantage over existing implementations of the Halbach array for HDD VCMs.

[0049] Physical Description of an Illustrative Operational Context

[0050] Embodiments may be used in the context of a digital data storage device (DSD) such as a hard disk drive (HDD). Thus, according to one embodiment, Figure 1 A plan view illustrating a conventional HDD 100 is shown to help describe how a conventional HDD generally operates.

[0051] Figure 1The functional arrangement of components of the HDD 100 including a slider 110b is illustrated, the slider including a magnetic read-write head 110a. The slider 110b and the head 110a may be collectively referred to as a head slider. The HDD 100 includes at least one head gimbal assembly (HGA) 110 having a head slider, a lead suspension 110c attached to the head slider typically 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 respectively writing and reading information stored on the medium 120 of the HDD 100. The medium 120 or a plurality of disk media may be attached to the spindle 124 using a disk clamp 128.

[0052] The HDD 100 also includes an arm 132 attached to the HGA 110, a carriage 134, a voice coil motor (VCM) including an armature 136 including a voice coil 140 attached to the carriage 134, and a stator 144 including a voice coil magnet (not visible). 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 the portion of the media 120, which are collectively mounted on a pivot shaft 148 with an interposed pivot bearing assembly 152. In the case of an HDD having multiple disks, the carriage 134 may be referred to as an "E-block" or comb because the carriage is arranged to carry an array of linked arms, giving it the appearance of comb teeth.

[0053] The assembly including a head gimbal assembly (e.g., HGA 110) having a flexure to which a head slider is coupled, an actuator arm (e.g., arm 132) to which the flexure is coupled, and / or a load beam, 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 also includes an electrical interconnect component. Generally speaking, the HSA is an assembly that is configured to move a head slider to access a portion of the medium 120 for read and write operations.

[0054] Further references Figure 1, electrical signals including write signals to the head 110a and read signals from the head (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" (FPC)). The interconnect between the flexible cable 156 and the head 110a may include an arm electronics (AE) module 160, which may have an onboard preamplifier for the read signal and other read channel and write channel electronic components. The AE module 160 may be attached to the carriage 134, as shown. The flexible cable 156 may be coupled to an electrical connector block 164, which in some configurations provides electrical connectivity through an electrical feed-through provided by the HDD housing 168. The HDD housing 168 (or "housing base" or "baseboard" or "motor base assembly" or simply "base") together with the HDD cover provides a semi-sealed (or hermetically sealed, in some configurations) protective housing for the information storage components of the HDD 100.

[0055] Other electronic components, including a 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 head 110a of the HGA 110. The electrical signal provided to the drive motor causes the drive motor to rotate, thereby providing torque to the spindle 124, which in turn is transmitted to the medium 120 attached to the spindle 124. As a result, the medium 120 rotates in the 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 flies above the surface of the medium 120 without making contact with the thin magnetic recording layer that records information. Similarly, in an HDD that utilizes a lighter-than-air gas (such as helium for non-limiting example), the rotating medium 120 forms an air cushion that acts as a gas or fluid bearing on which the slider 110b rides.

[0056] 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 on which the information is recorded. As a result, the armature 136 of the VCM swings through the arc 180, which enables the head 110a of the HGA 110 to access the respective tracks on the medium 120. The information is stored in a plurality of 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 a plurality of sectorized track portions (or "track sectors") 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 an ABCD-servo burst signal pattern (which is information identifying the track 176). When accessing track 176, a read element of head 110a of HGA 110 reads a servo burst signal pattern which provides a position error signal (PES) to the servo electronics, which in turn controls an electrical signal provided to the voice coil 140 of the VCM, thereby enabling head 110a to follow track 176. Upon finding track 176 and identifying a particular sectorized track portion 188, head 110a either reads information from track 176 or writes information to track 176 in accordance with instructions received by the disk controller from an external agent, such as a microprocessor of a computer system.

[0057] The electronic architecture of the HDD includes multiple electronic components for performing their respective HDD operating functions, such as a hard disk controller ("HDC"), an interface controller, an arm electronic module, a data channel, a motor driver, a servo processor, a buffer memory, etc. Two or more such components may be combined on a single integrated circuit board called a "system on a chip" ("SOC"). Several, if not all, of such electronic components are typically arranged on a printed circuit board that is coupled to the bottom side of the HDD, such as to the HDD housing 168.

[0058] Reference herein to hard disk drives, such as reference Figure 1The HDD 100 shown and described may include an information storage device sometimes referred to as a "hybrid drive." A hybrid drive generally refers to a storage device that has the functionality of a conventional HDD (see, for example, HDD 100) combined 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, which is electrically erasable and programmable. Because the operation, management, and control of different types of storage media are generally different, the solid-state portion of the hybrid drive may include its own corresponding controller functionality, which may be integrated into a single controller along with the HDD functionality. The hybrid drive may be constructed and configured to operate and utilize the solid-state portion in a variety of ways, such as, as a non-limiting example, using the solid-state memory as a cache memory, for storing frequently accessed data, for storing I / O intensive data, and the like. In addition, the hybrid drive may be constructed and configured to be essentially two storage devices in a single housing, namely a conventional HDD and an SSD, with one or more interfaces for host connection.

[0059] Extensions and replacements

[0060] In the foregoing description, embodiments of the present invention have been described with reference to a large number of specific details, which may vary according to different specific implementations. Therefore, various modifications and changes may be made to the embodiments without departing from the broader essence and scope of the embodiments. Therefore, the present invention and the applicant's sole and exclusive indicator of the present invention are a set of claims issued by this patent application in the specific form in which such claims are issued, including any subsequent corrections. Any definition of the terms contained in these claims explicitly set forth herein should determine the meaning of these terms used in the claims. Thus, limitations, elements, characteristics, features, advantages or attributes that are not explicitly cited in the claims should not limit the scope of this claim in any way. Therefore, this specification and the drawings are considered to be illustrative rather than restrictive.

[0061] Additionally, in this description, certain process steps may be shown in a particular order, and letters and alphanumeric labels may be used to identify certain steps. Unless expressly indicated in the specification, the embodiments are not necessarily limited to any particular order of performing such steps. In particular, these labels are used only to facilitate identification of the steps and are not intended to specify or require a particular order of performing such steps.

Claims

1. A method of assembling a voice coil motor (VCM), the method comprising: forming an opening in the yoke; attaching a main magnet to an inner surface of the yoke; installing a cross-traffic magnet into the passage of the main magnet through the opening in the yoke; as well as A plug is installed into the opening in the yoke.

2. The method according to claim 1, further comprising: After the main magnet is attached and before the orthogonal traffic magnet is installed, the main magnet is charged to set opposite magnetization directions on respective sides of the boundary. 3 . The method of claim 2 , wherein installing the cross-traffic magnet comprises installing the cross-traffic magnet substantially at the boundary.

4. The method according to claim 1, further comprising: Prior to installation into the main magnet, the orthogonal traffic magnet is charged to set a magnetization direction substantially orthogonal to the magnetization direction of the main magnet.

5. The method according to claim 1, further comprising: The channel is formed in the main magnet before the main magnet is attached, the channel having a shape consistent with the orthogonal traffic magnet. 6 . The method of claim 5 , wherein forming the channel comprises forming a channel extending from a proximal side toward a distal side of the main magnet but not extending to the distal side.

7. The method of claim 1, wherein installing the plug comprises installing a plug composed of the same material as the yoke.

8. The method according to claim 1, further comprising: forming an opening in the second yoke; attaching a second main magnet to an inner surface of the second yoke; charging the second main magnet to set opposite magnetization directions on respective sides of the magnetic boundary; installing a pre-charged orthogonal traffic magnet into the channel of the second main magnet through the opening in the second yoke; as well as A plug is installed into the opening in the second yoke.

9. The method according to claim 8, further comprising: The yoke, the main magnet, and the orthogonal traffic magnet assembly are coupled to the second yoke, the second main magnet, and the second orthogonal traffic magnet assembly.

10. A voice coil motor produced according to the method of claim 9.

11. A voice coil motor (VCM), the VCM comprising: a first yoke including an opening therethrough, the opening being filled with a first plug; a first main magnet coupled to the first yoke and having a proximal side adjacent to the first yoke and having an opposite distal side, the first main magnet being configured with opposite magnetic poles having opposite magnetization directions on respective sides of a first boundary; a first orthogonal traffic magnet embedded in the first main magnet through the opening in the first yoke and coupled to the first main magnet and having a proximal side adjacent to the first yoke, the first orthogonal traffic magnet being configured with a magnetization direction substantially orthogonal to the magnetization direction of the first main magnet; a second yoke including an opening therethrough, the opening being filled with a second plug; a second main magnet coupled to the second yoke and having a proximal side adjacent to the second yoke and having an opposite distal side, the second main magnet being configured with opposite magnetic poles having opposite magnetization directions on respective sides of the second boundary; and A second orthogonal traffic magnet, which is embedded in the second main magnet and coupled to the second main magnet through the opening in the second yoke and has a proximal side adjacent to the second yoke, and the second orthogonal traffic magnet is configured with a magnetization direction that is substantially orthogonal to the magnetization direction of the second main magnet.

12. The VCM of claim 11, wherein the first orthogonal traffic magnet is substantially embedded at the first boundary and the second orthogonal traffic magnet is substantially embedded at the second boundary.

13. The VCM of claim 11, further comprising: a first channel extending from the proximal side of the first main magnet toward the distal side but not to the distal side, and in which the first orthogonal traffic magnet is embedded; and A second channel extends from the proximal side of the second main magnet toward the distal side but does not extend to the distal side, and the second orthogonal traffic magnet is embedded in the second channel. 14 . The VCM of claim 13 , wherein the first channel extends from a front side to a rear side of the first main magnet, and the second channel extends from a front side to a rear side of the second main magnet.

15. The VCM of claim 11, wherein the first yoke and the first plug are composed of the same material.

16. A hard disk drive (HDD), the HDD comprising: a plurality of magnetic disk media rotatably mounted on a spindle motor; a plurality of head sliders, each of the head sliders accommodating a read-write transducer configured to read from and write to a corresponding disk medium of the plurality of disk media; and a voice coil motor (VCM) assembly configured to move the plurality of head sliders to access portions of the plurality of disk media; The VCM components include: a first yoke including an opening therethrough, the opening being filled with a first plug composed of the same material as the first yoke, a first main magnet coupled to the first yoke and having a proximal side adjacent to the first yoke and having an opposite distal side, the first main magnet being configured with opposite magnetic poles having opposite magnetization directions on respective sides of a first boundary, a first orthogonal traffic magnet embedded in the first main magnet through the opening in the first yoke and coupled to the first main magnet and having a proximal side adjacent to the first yoke, the first orthogonal traffic magnet being configured with a magnetization direction substantially orthogonal to the magnetization direction of the first main magnet, a second yoke including an opening therethrough, the opening being filled with a second plug composed of the same material as the second yoke, a second main magnet coupled to the second yoke and having a proximal side adjacent to the second yoke and having an opposite distal side, the second main magnet being configured with opposite magnetic poles having opposite magnetization directions on respective sides of a second boundary, and A second orthogonal traffic magnet, which is embedded in the second main magnet and coupled to the second main magnet through the opening in the second yoke and has a proximal side adjacent to the second yoke, and the second orthogonal traffic magnet is configured with a magnetization direction that is substantially orthogonal to the magnetization direction of the second main magnet. 17 . The HDD of claim 16 , wherein the magnetization direction of the first orthogonal traffic magnet is opposite to the magnetization direction of the second orthogonal traffic magnet.

18. The HDD of claim 16, wherein the first orthogonal traffic magnet is substantially embedded at the first boundary and the second orthogonal traffic magnet is substantially embedded at the second boundary.

19. The HDD according to claim 16, further comprising: a first channel extending from the proximal side of the first main magnet toward the distal side but not to the distal side, and in which the first orthogonal traffic magnet is embedded; and A second channel extends from the proximal side of the second main magnet toward the distal side but does not extend to the distal side, and the second orthogonal traffic magnet is embedded in the second channel.

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