Recessed base for magnetic memory device

Abstract

The basis for magnetic storage devices requires magnetic storage devices and manufacturing methods that help reduce power loss resulting from the resistance when the disk rotates. [Solution] The base 130 for the magnetic memory device 100 includes a base plate 152, a side wall 154 extending from the base plate, and an internal cavity 114 defined by the base plate and the side wall. The base plate includes an outer surface 101 and an inner surface 106 opposite to the outer surface. The inner surface at least partially defines the internal cavity. The inner surface includes a substantially flat surface and grooves 108 formed on the substantially flat surface. The thickness of the base plate varies. The minimum thickness of the base plate is defined by at least one of the grooves.

Description

Technical Field

[0001] The present disclosure generally relates to magnetic storage devices, and more specifically, to a recessed base for magnetic storage devices.

Background Art

[0002] Magnetic storage devices such as hard disk drives (HDDs) are widely used to store digital data or electronic information such as corporate data processing systems, computer workstations, portable computing devices, digital audio players, and digital video players. Generally, an HDD includes a read / write head that helps facilitate data storage on a magnetic disk. Each read / write head is supported on a suspension assembly. Some HDDs include a suspension assembly having a flexure.

Summary of the Invention

[0003] There is a need for a magnetic storage device and a manufacturing method that helps reduce power loss resulting from the resistance of gas between the disk and the base of a magnetic storage device when the disk rotates. The subject matter of the present application has been developed in view of the current state of magnetic storage devices, and specifically, in view of the problems and needs in the art as described above that have not yet been fully solved by currently available magnetic storage devices. Accordingly, embodiments of the present disclosure overcome at least some of the disadvantages of the prior art.

[0004] The following is a non-exhaustive list of examples of the subject matter disclosed herein, which may or may not be claimed.

[0005] This specification discloses a base for a magnetic storage device. The base includes a base plate, side walls extending from the base plate, and an internal cavity defined by the base plate and the side walls. The base plate includes an outer surface and an inner surface opposite to the outer surface. The inner surface at least partially defines the internal cavity. The inner surface includes a substantially flat surface and grooves formed on the substantially flat surface. The thickness of the base plate varies. The minimum thickness of the base plate is defined by at least one of the grooves. The subject matter described herein is characterized by Embodiment 1 of this disclosure.

[0006] Each groove has a substantially circular shape. The subject matter described above in this paragraph is characterized by Embodiment 2 of the present disclosure, which also includes the subject matter described in Embodiment 1.

[0007] The minimum thickness of the base plate defined by at least one of the grooves is 20 percent or more of the maximum thickness of the base plate. The subject matter described herein is characterized by Example 3 of the present disclosure, which also includes the subject matter described in any one of Examples 1 to 2 above.

[0008] The grooves are spaced at equal distances. The subject matter described above in this paragraph is characterized by Embodiment 4 of the present disclosure, which also includes the subject matter described in any one of Embodiments 1 to 3 above.

[0009] Furthermore, a magnetic storage system is disclosed herein. The magnetic storage system includes a base and a number of disks configured to rotate about an axis. The base includes a base plate, side walls extending from the base plate, and an internal cavity defined by the base plate and side walls, which receives the number of disks. The base plate includes an outer surface and an inner surface opposite to the outer surface. The inner surface at least partially defines the internal cavity. The inner surface includes a substantially flat surface and grooves formed on the substantially flat surface. The thickness of the base plate varies. The minimum thickness of the base plate is defined by at least one of the grooves. The subject matter described herein is characterized by Embodiment 5 of the present disclosure.

[0010] The groove extends radially outward in a direction away from the axis. The subject matter described above in this paragraph is characterized by Embodiment 6 of the present disclosure, which also includes the subject matter described in Embodiment 5.

[0011] At least one of the grooves has a length of 20 percent or more and 90 percent or less of the radius of each disk of the above-mentioned quantity of disks. The subject matter described herein is characterized by Example 7 of the present disclosure, which also includes the subject matter described in Example 6.

[0012] The entire groove is confined within the outer circumference of the disk. The subject matter described above in this paragraph is characterized by Embodiment 8 of the present disclosure, which also includes the subject matter described in Embodiments 5 to 7 above.

[0013] Each groove has a substantially conical shape. The grooves are arranged along multiple lines, each line extending radially outward away from the axis. The subject matter described above in this paragraph is characterized by Embodiment 9 of the present disclosure, which also includes the subject matter described in any one of Embodiments 5 to 8 above.

[0014] The groove of the first of the multiple lines is radially offset from the groove of the second of the multiple lines, and the second line is adjacent to the first line. The subject matter described herein is characterized by Example 10 of the present disclosure, which also includes the subject matter described in Example 9.

[0015] Each groove has a circular shape concentric with a number of disks. The subject matter described above in this paragraph is characterized by an embodiment 11 of the present disclosure, which also includes the subject matter described in any one of embodiments 5 to 10 above.

[0016] In the circumferential direction centered on the axis, the distance from the axis to each groove of the groove changes. The subject matter described above in this paragraph is characterized by Example 12 of the present disclosure, which also includes the subject matter described in any one of Examples 5 to 11 above.

[0017] The disk is configured to rotate in a first direction, and the distance increases in the circumferential direction opposite to the first direction. The subject matter described herein is characterized by an embodiment 13 of the present disclosure, which also includes the subject matter described in embodiment 12.

[0018] At least some of the grooves intersect the plane along which the axis is located. The subject matter described herein is characterized by Embodiment 14 of the present disclosure, which also includes the subject matter described in Embodiment 12 or 13 above.

[0019] The ratio of the number of discs to the number of grooves is between 0.05 and 10, including the values ​​at both ends. The subject matter described herein is characterized by Example 15 of the present disclosure, which encompasses Examples 5 to 14 above.

[0020] The outer surface is substantially flat and groove-free. The subject matter described herein is characterized by Example 16 of the present disclosure, which also includes Examples 5 to 15.

[0021] The base has a monolithic, integrated, and seamless structure. The subject matter described above in this paragraph is characterized by Example 17 of the present disclosure, which also includes Examples 5 to 16.

[0022] The maximum distance between the bottom disk and the inner surface of the above-mentioned number of disks closest to the base plate is 0.5 mm or more and 2.5 mm or less. The subject matter described herein is characterized by Example 18 of the present disclosure, which also includes Examples 5 to 17.

[0023] Each groove defines a recess in the base plate. The distance between the bottom disk of the above-mentioned number of disks closest to the base plate and the inner surface in the recess is greater than the distance between the bottom disk and any other part of the inner surface. The subject matter described herein is characterized by an embodiment 19 of the present disclosure, which also includes embodiments 5 to 18.

[0024] This specification further discloses a magnetic storage system. The magnetic storage system includes a base and a plurality of disks configured to rotate about an axis. The base includes a base plate, side walls extending from the base plate, and an internal cavity defined by the base plate and side walls and receiving the aforementioned number of disks. The base plate includes an outer surface and an inner surface opposite to the outer surface. The inner surface defines at least partially the internal cavity. The inner surface includes a substantially flat surface and means for varying the thickness of the base plate, so that the minimum thickness of the base plate is defined by the means for varying the thickness. The subject matter described herein is characterized by 20 embodiments of this disclosure.

[0025] The features, structures, advantages, and / or properties described in this disclosure can be combined in any preferred manner in one or more embodiments and / or implementations. Numerous specific details are provided in the following description to give a complete understanding of embodiments of the subject matter of this disclosure. Those skilled in the art will recognize that the subject matter of this disclosure may be implemented without one or more specific features, details, components, materials, and / or methods of a particular embodiment or implementation. In other examples, additional features and advantages may be recognized in certain embodiments and / or implementations that may not be present in all embodiments or implementations. Furthermore, in some examples, well-known structures, materials, or operations are not shown in detail or described in order to avoid obscuring aspects of the subject matter of this disclosure. The features and advantages of the subject matter of this disclosure may be more fully apparent from the following description and the accompanying claims, or may be acquired by implementing the subject matter as described below. [Brief explanation of the drawing]

[0026] To facilitate an understanding of the advantages of the present disclosure, a more specific description of the present disclosure, briefly described above, will be made by referring to specific embodiments shown in the accompanying drawings. It is understood that these drawings show only typical embodiments of the present disclosure and should not be considered as limiting its scope. Through the use of the accompanying drawings, the subject matter of the present application will be described and explained with additional particularity and detail. [Figure 1A] FIG. 1A is a perspective view of a magnetic storage device according to one or more embodiments of the present disclosure. [Figure 1B] FIG. 1B is a cross-sectional side view of the magnetic storage device taken along plane A of FIG. 1A according to one or more embodiments of the present disclosure. [Figure 1C] FIG. 1C is a close-up cross-sectional side view of the magnetic storage device taken along plane A of FIG. 1A according to one or more embodiments of the present disclosure. [Figure 2A] FIG. 2A is a plan view of the base of the magnetic storage device according to one or more embodiments of the present disclosure. [Figure 2B] FIG. 2B is a cross-sectional side view of the base of the magnetic storage device taken along plane B of FIG. 2A according to one or more embodiments of the present disclosure. [Figure 3A] FIG. 3A is a plan view of the base of the magnetic storage device having a circular groove according to one or more embodiments of the present disclosure. [Figure 3B] FIG. 3B is a cross-sectional side view of the base of the magnetic storage device taken along plane B of FIG. 3A according to one or more embodiments of the present disclosure. [Figure 4A] FIG. 4A is a plan view of the base of the magnetic storage device having a plurality of grooves according to one or more embodiments of the present disclosure. [Figure 4B] FIG. 4B is a cross-sectional side view of the base of the magnetic storage device taken along plane B of FIG. 4A according to one or more embodiments of the present disclosure. <​​​​​​​​Throughout this specification, references to “one example,” “an example,” or similar terms mean that certain features, structures, or characteristics described in relation to these examples are included in at least one example of this disclosure. Throughout this specification, the phrases “in one example,” “in an example,” and similar terms do not necessarily all refer to the same example. Similarly, the term “implementation” means an implementation having certain features, structures, or characteristics described in relation to one or more examples of this disclosure. However, unless there is an express correlation to indicate otherwise, an implementation may be associated with one or more examples.

[0028] Referring to Figure 1A, a magnetic storage device 100 according to one embodiment is depicted as a hard disk drive (HDD). However, in other embodiments, the magnetic storage device 100 may be any of various magnetic storage devices without departing from the essence of the subject matter of this disclosure. The magnetic storage device 100 includes a housing 102 that seals or encloses an internal cavity 114 defined within the housing. The housing 102 includes a base 130 and a cover 132 (shown with dashed lines so as not to obscure the internal mechanism of the magnetic storage device 100 within the internal cavity 114 of the housing 102). The cover 132 is coupled to the base 130 so as to enclose the internal cavity 114 from the environment outside the housing 102. In some implementations, a seal or gasket is positioned between the base 130 and the cover 132 to facilitate sealing between the base 130 and the cover 132. In some embodiments, the base 130 is made of a metallic material such as stainless steel or aluminum.

[0029] Referring to Figures 1A to 5, in some embodiments, the base 130 includes a base plate 152 and side walls 154 extending from the base plate 152. In one or more embodiments, the internal cavity 114 is defined by the base plate 152 and the side walls 154. In some embodiments, the base plate 152 includes an outer surface 101 and an inner surface 106 opposite to the outer surface 101. The inner surface 106 defines the internal cavity 114 at least partially.

[0030] The magnetic storage device 100 includes various mechanisms located within an internal cavity 114 of the housing 102. Referring to Figure 1A, in some embodiments, the magnetic storage device 100 includes a carriage 103, a disk 115, a spindle motor 121, and a voice coil motor (VCM) 125 within the internal cavity 114. Referring again to Figure 1A, the carriage 103 includes a head stack assembly which includes a plurality of carriage arms 105 and at least one head gimbal assembly 109 (e.g., suspension) coupled to the distal end of each carriage arm of the plurality of carriage arms 105. Each head gimbal assembly 109 includes a suspension assembly and a slider 142. The slider 142 includes at least one read / write head coupled to (e.g., embedded in) the housing of the slider 142. The magnetic storage device 100 in Figure 1A is shown to have five carriage arms 105 and four disks 115, but in other embodiments, the magnetic storage device 100 may have fewer or more carriage arms 105 or fewer or more disks 115. In one embodiment, each side of each carriage arm 105 facing a disk 115 has a head gimbal assembly 109 (for example, one of the bottom and top carriage arms 105 may have one head gimbal assembly 109, and one of the intermediate carriage arms 105 between the bottom carriage arm 105 and the top carriage arm 105 may have two head gimbal assemblies 109). Similarly, the magnetic storage device 100 is shown to have one spindle motor 121 and one VCM 125, but in other embodiments, the magnetic storage device 100 may have any number of spindle motors 121 and VCM 125.

[0031] The spindle motor 121 is coupled to the base 130. In some embodiments, the spindle motor 121 is coupled to the base 130 at a base plate 152. Generally, the spindle motor 121 includes a stationary portion fixed immovably to the base 130 and a spindle 122 that is rotatable relative to the stationary portion and the base 130. Thus, the spindle 122 of the spindle motor 121 can be considered as part of the spindle motor or as an integral part of the spindle motor. Generally, the spindle motor 121 is operable to rotate the spindle 122 relative to the base 130. The disks 115, or platters, are rotatably fixed to the spindle 122 of the spindle motor 121 via respective hubs that are rotatably fixed to each disk 115 and the spindle 122. As the spindle 122 of the spindle motor 121 rotates, the disks 115 rotate accordingly. In this way, the spindle 122 of the spindle motor 121 defines the axis of rotation for each disk 115. The spindle motor 121 can be controlled to operate in a way that rotates the disks 115 in the rotational direction 190 by a controlled amount at a controlled speed.

[0032] Referring to Figures 1A and 1B, each of the disks 115 may be one of various types of magnetic recording media. Generally, in one embodiment, each disk 115 includes a substrate and a magnetic material applied directly or indirectly on the substrate. For example, the magnetic material of the disk 115 may be a conventional granular magnetic recording disk or wafer having magnetic layer bits, each bit having multiple magnetic particles. In a granular magnetic medium, all bits are coplanar, and the surface 116 of the disk is substantially smooth and continuous. In one embodiment, each bit has a magnetic dipole moment that can have in-plane (longitudinal) or out-of-plane (perpendicular) orientation.

[0033] As the disk 115 rotates in read / write mode, the VCM 125 electromagnetically engages with the voice coil of the carriage arm 105, causing the carriage arm 105 and the head gimbal assembly 109 coupled to it to rotate relative to the disk 115 along a plane parallel to the read / write surface of the disk 115. Rotating the carriage arm 105 allows the read / write head of the head gimbal assembly 109 to be positioned on a specific radial area of ​​the corresponding read / write surface 116 of the disk 115 for read and / or write operations. The VCM 125 is fixed to the base 130 in engagement with the voice coil of the carriage arm 105, and the carriage arm is rotatably coupled to the base 130 via a spindle 127 extending through the carriage 103. Generally, the spindle 127 defines the axis of rotation on which the carriage arm 105 rotates when actuated by the VCM 125.

[0034] The carriage arms 105 are fixed immovably to the base of the carriage 103 (e.g., integrally formed as a single monolithic body) and extend away from it, spaced apart from each other. In some implementations, the carriage arms 105 are equidistant from each other and extend parallel to each other. One of each disk 115 is positioned between adjacent carriage arms 105. In idle mode (e.g., when no read-write operations are being performed), the VCM 125 is activated to rotate the carriage arms 105 radially outward relative to the disks 115, thereby placing the head gimbal assembly 109 on or unloading it from the ramp support 117 fixed to the base 130.

[0035] The read / write head embedded in the slider 142 includes at least one read transducer and at least one write transducer. The read transducer is configured to detect the magnetic properties (e.g., magnetic bit pattern) of the disk 115 and convert the magnetic properties into electrical signals. The write transducer, in turn, changes the magnetic properties of the disk 115 in response to the electrical signals. For each head gimbal assembly 109, electrical signals are transmitted to and from the read / write head via electrical traces or wires formed in or coupled to the slider 142 and the flexure. The electrical traces of the slider 142 and the flexure are electrically interconnected (e.g., via solder welds electrically connecting the corresponding electrical contact pads (and corresponding electrical traces) of the slider 142 and the flexure) to facilitate the transmission of electrical signals between the read / write head of the magnetic storage device 100 and the flex connector 104. The flex connector 104 communicates with the control module 107 of the magnetic storage device 100 (see, for example, Figure 1A). The control module 107 is configured to process electrical signals and facilitate the communication of electrical signals between the magnetic storage device 100 and one or more external computing devices. Generally, the control module includes software, firmware, and / or hardware used to control the operation of various components of the magnetic storage device 100. The control module may include a printed circuit board on top of or inside which the hardware is mounted.

[0036] Figures 1B and 1C are cross-sectional side views of the base 130 of the magnetic storage device 100, taken along plane A in Figure 1A. Referring to Figures 1B and 1C, the disk 115 is displaced from the inner surface 106. As the disk 115 rotates around the axis 110, it can dissipate energy when it encounters resistance, such as air resistance or resistance between the disk 115 and the gas (e.g., air or helium). The rotation of the disk 115 creates airflow, resulting in friction between the disk 115 and the gas in the cavity 114, which can lead to power loss. This power loss can contribute to excess heat generated within the magnetic storage device 100, potentially reducing the overall efficiency and performance of the magnetic storage device 100. In some embodiments, increasing the gap between the inner surface 106 and adjacent disks 115A may help reduce this power loss. However, reducing the maximum thickness t1 of the base plate 152 may reduce the rigidity of the base plate 152, and as a result, reduce the resistance of the magnetic storage device 100 to shock and vibration. Embodiments of the present disclosure include a magnetic storage device 100 having grooves 108 formed in the inner surface 106 that vary the thickness of the base plate 152, and thus can help reduce power loss caused by gas resistance between the disk 115 and the inner surface 106 while maintaining the rigidity of the base plate 152.

[0037] Referring to Figures 1B, 1C, 2B, 3B, and 4B, in some embodiments, the inner surface 106 includes a substantially flat surface in which grooves 108 are formed. In some embodiments, at least one of the grooves 108 defines a minimum thickness tmin of the base plate 152 (see, for example, Figure 1C). In other words, the thickness of the base plate 152 is minimum where the grooves 108 are located (for example, the minimum thickness tmin is equal to the distance between the bottom surface of the groove 108 and the outer surface 101). The distance d2 between the inner surface 106 and the surface 116 of the disk 115A adjacent to the inner surface 106 (i.e., the closest) is maximum at the grooves 108. In some embodiments, the grooves 108 are formed by recessing the inner surface 106 away from the disk 115A. In some embodiments, each of the grooves 108 defines a recess 118 in the base plate 152. The base plate 152 includes one or more non-recessed areas 119 adjacent to each recessed area 118. At least one of the non-recessed areas 119 defines the maximum thickness t1 of the base plate 152.

[0038] Referring to Figures 1B, 1C, 2A, 3A, 4A, and 5A, in some embodiments, the entirety of each groove 108 is confined within the outer circumference 111 of the disk 115. Each groove 108 extends from a first end 156 to a second end 158 (see, for example, Figure 2A). Thus, both the first end 156 and the second end 158 of each groove 108 are located within the outer circumference 111 in certain embodiments. In some embodiments, the area of ​​the base plate 152 within the outer circumference 111 of the disk 115 includes a plurality of grooves 108 on both sides of the shaft 110. The base plate 152 includes a plurality of recesses 118 and non-recesses 119 on both sides of the shaft 110 but within the outer circumference 111.

[0039] Referring to Figure 1B, in some embodiments, the inner surface 106 extends substantially parallel to the surface of the disk 115 in both recessed areas 118 (e.g., the bottom surface) and non-recessed areas 119 (e.g., the flat portions between grooves). In the radially inward direction toward the axis 110, the thickness of the base plate 152 decreases to a minimum (i.e., tmin) where any non-recessed area 119 contacts an adjacent recessed area 118. In some embodiments, the base plate 152 is coupled to the side wall 154 in the non-recessed areas 119.

[0040] Referring to Figures 2A, 3A, 4A, and 5A, in some embodiments, portion 160 of the base plate 152 over which the carriage arm 105 moves does not include the groove 108. Portion 160 interrupts the pattern of the groove 108. According to some embodiments, the thickness of the base plate 152 in portion 160 is less than the thickness t1 of the non-recessed portion 119. In at least one embodiment, the thickness of the base plate 152 in portion 160 is less than the minimum thickness tmin described herein. In some embodiments, the height of the base plate 152 is lower in portion 160.

[0041] In some embodiments, the outer surface 101 is substantially flat and substantially grooveless, so as to help maintain the minimum thickness tmin of the base plate 152 while increasing the maximum distance d2 between the disk 115 and the inner surface 106. Thus, the portion of the outer surface 101 opposite the groove 108 does not contain the groove. In some embodiments, the outer surface 101 is substantially parallel to one of the surfaces of the disk 115.

[0042] In some embodiments, the minimum thickness tmin of the base plate 152 defined by the groove 108 is 50 percent or more of the maximum thickness t1 of the base plate 152. In one embodiment, the maximum thickness t1 is the thickness of the non-recessed 119 adjacent to the recessed 118. In some embodiments, the minimum thickness tmin is 40 percent or more of the maximum thickness t1 of the base plate 152. In some embodiments, the minimum thickness tmin is 20 percent or more of the maximum thickness t1 of the base plate 152. In one or more embodiments, the minimum thickness tmin is 80 percent or less of the maximum thickness t1. In even more specific embodiments, the minimum thickness tmin is 60 percent to 80 percent of the maximum thickness t1, including both ends. In some embodiments, the minimum thickness tmin is 65 percent to 75 percent of the maximum thickness t1, including both ends. According to at least one embodiment, the maximum thickness t1 is 1.5 millimeters ("mm") to 3.5 mm, including both ends.

[0043] In some embodiments, the difference between the distance d3 (between the disk 115 and the non-recessed 119 of the inner surface 106) and the distance d2 (between the disk 115 and the recessed 118 adjacent to the non-recessed 119) defines the groove depth d1. The groove depth d1 can also be defined as the difference between the maximum thickness t1 and the minimum thickness tmin, where the portion of the base plate 152 directly adjacent to the groove 108 defines the maximum thickness t1, and the groove 108 defines the minimum thickness tmin. In some embodiments, the groove depth d1 is constant throughout the length L1 of the groove 108. In some embodiments, the groove depth d1 is about 0.7 millimeters ("mm"). In some embodiments, the groove depth d1 is between 0.3 mm and 1.1 mm, including the values ​​at both ends. In some embodiments, the groove depth d1 is about 0.5 mm. In some embodiments, the groove depth d1 is approximately equal to the distance d3 between the non-recessed 119 of the inner surface 106 and the disk 115. In some alternative embodiments, the groove depth d1 is variable through the length L1 of at least one of the grooves 108.

[0044] In various embodiments, the maximum distance d2 (between the bottom disk 115 closest to the base plate 152 and the inner surface 106 in the recess 118) is greater than the distance d3 (between the bottom disk 115 and any other part of the inner surface 106, such as the non-recessed 119). In some embodiments, the distance d2 varies within the groove 108. In other embodiments, the distance d2 remains constant along the length L1 of the groove 108. In some embodiments, the distance d3 between the disk 115 and the non-recessed 119 varies within the outer circumference 111 of the disk 115. In other embodiments, the distance d3 between the disk 115 and the non-recessed 119 is constant within the outer circumference 111. In some embodiments, the distance d3 between the disk 115 and the non-recessed 119 is less than or equal to the depth d1 of the groove 108.

[0045] In some embodiments, the maximum distance d2 between the bottom disk 115A and the inner surface 106 is approximately 1 mm. In some embodiments, the maximum distance d2 is 2.5 mm or less. In some embodiments, the maximum distance d2 is less than or equal to the depth d1 of the groove 108. In some embodiments, the maximum distance d2 is greater than the thickness t2 of the disk 115.

[0046] In some embodiments, a minimum thickness tmin is sufficient to maintain the rigidity of the base plate 152 in the recess 118. In one or more embodiments, the rigidity of the base plate 152 in the recess 118 is 1100 Newtons per millimeter ("N / mm") or greater. In some embodiments, the rigidity in the recess 118 is 1150 N / mm or greater. In some embodiments, the rigidity in the recess 118 is 95 percent or greater of the rigidity of the base plate 152 in the non-recessed 119. In some embodiments, the rigidity in the recess 118 is 95 percent to 99 percent of the rigidity of the base plate 152 in the adjacent non-recessed 119, including both ends. In some embodiments, the rigidity in the recess 118 is 95.1 percent to 98 percent of the rigidity of the adjacent non-recessed 119, including both ends.

[0047] In some embodiments, the base plate 152 has a monolithic, integrated, and seamless structure. In various embodiments, the base 130 also has a monolithic, integrated, and seamless structure. In such embodiments, the recessed 118 and non-recessed 119 of the base plate 152 are monolithic in structure. The non-recessed 119 is connected to the spindle motor 121.

[0048] Referring to Figures 2A, 3A, 4A, and 5A, in some embodiments, all or at least a subset of the grooves 108 are spaced at equal distances. As shown in Figure 2A, in some embodiments, each of the grooves 108 is spaced equally apart in the circumferential direction around the axis 110 with respect to adjacent grooves. The angle θ defined between adjacent grooves 108 can be equal for each pair of adjacent grooves 108. Referring to Figures 3A and 3B, in some embodiments, at least some of the grooves 108 are spaced at equal distances in the radial direction extending outward from the axis 110. In some embodiments, only a subset of the grooves 108 are spaced at equal distances.

[0049] Referring to Figure 4A, in some embodiments, grooves 108 located on a particular line 112 are spaced equidistant from each other in the radial direction extending outward from the axis 110. In various embodiments, the lines 112 on which the grooves 108 are located are spaced equidistant from each other in the circumferential direction. In some embodiments, the grooves 108 are located in concentric circles of grooves 108 that are equidistant from each other. Thus, in certain embodiments, the grooves 108 can be spaced equidistant in both the radial and circumferential directions.

[0050] Referring to Figure 3A, in some embodiments, equidistant grooves 108 are equidistant along the entire length of the groove 108. Although not shown in the figure, in some embodiments, the grooves 108 are equidistant at the first groove end 156 but not at the second groove end 158 opposite to the first groove end 156. Referring to Figures 2A and 5, in some embodiments, the circumferential distance between adjacent grooves 108 varies along the length L1 of the groove 108. The circumferential distance between the first ends 156 of adjacent grooves 108 is less than the circumferential distance between the second ends 158 of adjacent grooves 108. The second end 158 is on the opposite side of the first end 156.

[0051] Referring to Figures 2A and 2B, in some embodiments, the grooves 108 extend radially outward in the radial direction away from the axis 110. These grooves 108 may be elongated grooves. Each groove is substantially perpendicular to the axis 110. Furthermore, each groove 108 is substantially parallel to the radius d4 of the disk 115. Referring to Figures 1B, 1C, and 2A, 2B, in some embodiments, at least one groove 108 has a length L1 of at least 20 percent and not more than 90 percent of the radius d4 of each of the above-mentioned disks 115. In some embodiments, the groove length L1 is about 25 percent of the radius d4 of the disk 115. In some embodiments, the groove length L1 is 10 mm to 15 mm, including the values ​​at both ends.

[0052] Figure 2B shows a cross-sectional side view of the base 130 taken along plane "B" of Figure 2A. Referring to Figure 2B, in some embodiments, the base plate 152 includes a gap. In some embodiments, the groove 108 extends along a length L1 between the gap and the side wall 154, or between the gap and the outer circumference 111 of the disk 115. In various embodiments, the inner surface 106 includes a circular groove 129 concentric with the axis 110. The circular groove 129 is located between the gap and the radial groove 108 in the radial direction extending outward from the axis 110.

[0053] In some embodiments, the angle α of the inner surface 106 with respect to the side wall 154 and / or axis 110 is about 90 degrees in the non-recessed 119 and recessed 118, and less than 90 degrees in the inclined portion 164 connecting the recessed 118 and the adjacent non-recessed 119. In some embodiments, the angle α is about 60 degrees.

[0054] In some embodiments, the distance between the gap and the groove 108 is greater than the length L1 of the groove 108. In some embodiments, the length L1 of the groove 108 is less than 70 percent of that distance. In one or more embodiments, the length L1 is between 10 percent and 50 percent of that distance, including the endpoints.

[0055] Referring to Figures 2B, 3B, and 4B, in some embodiments, the height of the base plate 152 varies within the base 130. In some embodiments, the depth d1 of the groove 108 is between 1.9 percent and 5.7 percent of the distance between the top of the inner surface 106 and the recess 118 in a direction substantially parallel to the side wall 154, including the values ​​at both ends.

[0056] Referring to Figures 3A and 3B, in some embodiments, at least one groove 108 is substantially circular in shape. Thus, each of the grooves 108 can have a circular shape concentric with the aforementioned number of disks 115. In such embodiments, the axis 110 defines the center point of the circle formed by at least one of the grooves 108. In some embodiments, a circular groove 108 having one radius is concentric with another circular groove 108 having a different radius.

[0057] Figure 3B is a cross-sectional side view of the base 130 taken along plane "B" of Figure 3A. Referring to Figure 3B, in some embodiments, the inner surface 106 includes a first circular groove 129 that is concentric with the axis 110 and located radially between the gap and the outer groove 108, extending outward from the axis 110. The outer groove 108 is one of several equidistant outer grooves 108. In some embodiments, the distance d8 between each of the equidistant outer grooves 108 is approximately 3 mm. In some embodiments, the distance d8 is between 1.5 mm and 4.5 mm, including the values ​​at both ends.

[0058] In some embodiments, the spacing d8 between the outer grooves 108 is 15 percent or less of the distance between the gap in the base plate 152 and the first outer groove 108. In some embodiments, the spacing d8 between the outer grooves 108 is 4 percent to 15 percent of the distance between the gap in the base plate 152 and the first outer groove 108, including both ends.

[0059] In some embodiments, the groove 108 forms an angle φ of approximately 120 degrees on the inner surface 106. In some embodiments, the angle φ of each groove 108 is the same. In some embodiments, the angle φ is between 90 degrees and 150 degrees, including the values ​​at both ends.

[0060] Referring to Figures 4A and 4B, in some embodiments the grooves are not elongated. Rather, at least one groove 108 may be substantially conical. In some embodiments, at least one of the grooves 108 has a hemispherical, cylindrical, cubic, rectangular, and / or triangular shape.

[0061] In some embodiments, the grooves 108 are arranged on multiple lines 112, each line 112 containing multiple aligned grooves 108, extending radially outward from the axis 110 in a direction parallel to the radius d4 of the disk 115. The grooves 108 of each line 112 are spaced equidistant radially from the axis 110. In some embodiments, the grooves 108 are arranged in a staggered pattern. The grooves 108 of line 112 among the multiple lines 112 are radially offset from the grooves 108 of adjacent lines 112. In some embodiments, the lines 112 are spaced equidistant circumferentially. The angle θ between adjacent lines 112 is approximately 5 degrees. In some embodiments, the angle θ between adjacent lines 112 is between 2 and 8 degrees, including the values ​​at both ends.

[0062] Figure 4B is a cross-sectional side view of the base 130 taken along plane "B" in Figure 4A. Referring to Figure 4B, in some embodiments, the groove 108 forms an angle φ of approximately 118 degrees on the inner surface 106. The angle φ is equal to twice the apex angle of the conical shape of the groove 108. In some embodiments, the angle φ is between 90 and 150 degrees, including the values ​​at both ends.

[0063] Referring to Figure 5, in some embodiments, the grooves 108 are formed as curves. For example, the grooves 108 may be substantially helical with respect to the axis 110. In some embodiments, the distance d9 from the axis 110 to each of the grooves 108 changes in the circumferential direction centered on the axis 110. According to certain embodiments, the grooves 108 intersect a plane "B" along which the axis is located. In some embodiments, multiple grooves 108 intersect plane "B". In some embodiments, three or more grooves 108 intersect plane "B". In some embodiments, each groove 108 is formed as part of a helix with respect to the axis 110. Each groove 108 may be part of a line that wraps around the axis 110 as a center point, while the distance d9 between the groove 108 and the axis 110 increases along the groove 108. The distance d9 between the groove 108 and the shaft 110 may increase from the first end 156 of the groove 108 to the second end 158 opposite the first end 156.

[0064] In some embodiments, the direction of the helix formed by at least one of the grooves 108 is opposite to the rotation of the disk 115 with respect to the axis 110. In some embodiments, the disk 115 is configured to rotate in a first direction r1, and the distance between the axis 110 and the grooves 108 increases in a circumferential direction r2 that is different from the first direction r1. In some embodiments, the circumferential direction r2 is opposite to the direction r1. In some embodiments, one of directions r1 and r2 is substantially clockwise, while the other of directions r1 and r2 is substantially counterclockwise. In some embodiments, direction r2 is clockwise.

[0065] In some embodiments, the ratio of the number of discs 115 to the number of grooves 108 is 0.05 to 10, including both values. In some embodiments, the number of discs 115 is 10 or more. In some embodiments, the number of discs 115 is 13 or less. In some embodiments, the number of grooves 108 is 2 to 40, including both values. In some embodiments, the recesses 118 of the inner surface 106 constitute 20 percent or more of the surface area of ​​the inner surface 106. In some embodiments, the recesses 118 constitute 70 percent or less of the above surface area.

[0066] Embodiments of the present disclosure include methods for forming grooves 108 in a base plate 152. Some methods include forming the grooves 108 in the base plate 152 during the formation of the base plate 152. Some embodiments include forming a base plate 152 having grooves 108 using a mold or stamp having protrusions corresponding to grooves 108. Some embodiments include forming grooves 108 by etching off material from a base plate substrate. Some embodiments include machining grooves 108 into the base plate 152.

[0067] In the above description, specific terms such as “up,” “down,” “upper,” “lower,” “horizontal,” “vertical,” “left,” “right,” “over,” and “under” may be used. These terms are used to clarify the description when dealing with relative relationships, where applicable. However, these terms are not intended to imply absolute relationships, positions, and / or orientations. For example, with respect to an object, the “upper” surface can become the “lower” surface simply by turning the object inside out. Yet, it is still the same object. Furthermore, the terms “including,” “comprising,” and “having,” and their variations, mean “including, but not limited to,” unless otherwise specified. The list of enumerated items does not implicitly mean that any or all of those items are mutually exclusive and / or mutually exclusive, unless otherwise specified. “A,” “an,” and “the” also mean “one or more,” unless otherwise specified. Furthermore, the term "plural" can be defined as "at least two."

[0068] The terms “about,” “substantially,” or “approximately” are defined in some embodiments to mean within + / - 5% of a given value, but in additional embodiments, any disclosure of “about,” “substantially,” or “approximately” may be further narrowed to mean within + / - 4% of a given value, within + / - 3% of a given value, within + / - 2% of a given value, within + / - 1% of a given value, or the exact given value, and may be claimed. Furthermore, when at least two values ​​of a variable are disclosed, such disclosure is specifically intended to include a range between the two values, whether they are disclosed in relation to a separate embodiment or example, and is specifically intended to include a range less than or equal to the smaller of the two values ​​and / or the larger of the two values. In addition, when at least three values ​​of a variable are disclosed, such disclosure is specifically intended to include a range between any two of the values, regardless of whether they are disclosed in relation to a separate embodiment or example, and is specifically intended to include a range less than or equal to at least value A and / or value B, where A may be any of the disclosed values ​​other than the largest disclosed value, and B may be any of the disclosed values ​​other than the smallest disclosed value.

[0069] As used herein, a system, apparatus, structure, article, element, component, or hardware “configured” to perform a particular function is not merely capable of performing the specified function after further modification, but is actually capable of performing the specified function without any modification. In other words, a system, apparatus, structure, article, element, component, or hardware “configured” to perform a particular function is specifically selected, created, implemented, used, programmed, and / or designed for the purpose of performing a particular function. As used herein, “configured” indicates an existing characteristic of the system, apparatus, structure, article, element, component, or hardware that enables the system, apparatus, structure, article, element, component, or hardware to perform a particular function without further modification. For the purposes of this disclosure, a system, apparatus, structure, article, element, component, or hardware described as “configured” to perform a particular function may be described as “adapted” and / or “operated” to perform that function, in addition or as a substitute.

[0070] In addition, instances in this specification in which one element is "joined" to another element can include direct and indirect joins. A direct join can be defined as one element joined to another element and in some contact with the other element. An indirect join can be defined as a join between two elements that do not directly contact each other but have one or more additional elements between the joined elements. Furthermore, as used herein, fixing one element to another element can include direct and indirect fixings. In addition, as used herein, "adjacent" does not necessarily mean contact. For example, one element may be adjacent to another element without contacting it.

[0071] As used herein, the phrase “at least one of” when used with a list of items means that one or more different combinations of the listed items may be used, and only one of the items in the list may be required. An item may be a specific object, thing, or category. In other words, “at least one of” means that any combination of items or number of items may be used from the list, but not all of the items in the list may be required. For example, “at least one of item A, item B, and item C” could mean item A; item A and item B; item B; item A, item B, and item C; item C; or item B and item C. In some cases, “at least one of item A, item B, and item C” could mean, for example, two of item A, one of item B, and ten of item C; four of item B and seven of item C; or several other preferred combinations.

[0072] Unless otherwise stated, terms such as “First,” “Second,” etc., are used herein solely as labels and are not intended to impose any order, position, or hierarchical requirements on the items they refer to. Furthermore, a reference to, for example, an item “Second,” does not require or exclude the presence of, for example, an item “First” or a lower-numbered item, and / or, for example, an item “Third” or a higher-numbered item.

[0073] This subject matter may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments should be considered in all respects to be illustrative and non-restrictive. All modifications that fall within the meaning and scope of the claims and equivalents should be included within those scopes.

Claims

1. A base for a magnetic memory device, A base plate comprising an outer surface and an inner surface opposite to the outer surface, the inner surface comprising a substantially flat surface and grooves formed on the substantially flat surface, wherein the thickness of the base plate varies and the minimum thickness of the base plate is defined by at least one of the grooves, A side wall extending from the base plate, A base comprising the base plate and the side wall, and the internal cavity defined by the base plate and the side wall.

2. The base according to claim 1, wherein each groove has a substantially circular shape.

3. The base according to claim 1, wherein the minimum thickness of the base plate defined by the at least one groove is 20 percent or more of the maximum thickness of the base plate.

4. The base according to claim 1, wherein the grooves are spaced at equal distances apart.

5. A magnetic memory system, A certain number of disks configured to rotate around an axis, It's the base, A base plate comprising an outer surface and an inner surface opposite to the outer surface, the inner surface comprising at least partially defining an internal cavity, the inner surface comprising a substantially flat surface and grooves formed on the substantially flat surface, wherein the thickness of the base plate varies, and the minimum thickness of the base plate is defined by at least one of the grooves, A side wall extending from the base plate, A magnetic storage system comprising a base, which includes an internal cavity defined by the base plate and the side wall, and which receives the number of disks.

6. The magnetic storage system according to claim 5, wherein the groove extends radially outward in a direction away from the axis.

7. The magnetic storage system according to claim 6, wherein at least one of the grooves has a length of 20 percent or more and 90 percent or less of the radius of each of the disks of the specified number of disks.

8. The magnetic storage system according to claim 5, wherein the entire groove is enclosed within the outer circumference of the disk.

9. Each of the grooves has a substantially conical shape, The magnetic storage system according to claim 5, wherein the grooves are arranged on a plurality of lines, and each line extends radially outward so as to move away from the axis.

10. The magnetic storage system according to claim 9, wherein the groove of the first line among the plurality of lines is radially offset from the groove of the second line among the plurality of lines, and the second line is adjacent to the first line.

11. The magnetic storage system according to claim 5, wherein each groove has a circular shape concentric with the aforementioned number of disks.

12. The magnetic storage system according to claim 5, wherein the distance from the axis to each groove of the groove changes in the circumferential direction centered on the axis.

13. The disk is configured to rotate in a first direction, and The magnetic storage system according to claim 12, wherein the distance increases in the circumferential direction opposite to the first direction.

14. The magnetic storage system according to claim 12, wherein at least some of the grooves intersect with a plane along which the axis is located.

15. The magnetic storage system according to claim 5, wherein the ratio of the number of disks to the number of grooves is 0.05 to 10, including the values ​​at both ends.

16. The magnetic storage system according to claim 5, wherein the outer surface is substantially flat and free of grooves.

17. The magnetic storage system according to claim 5, wherein the base is monolithic, integrated, and has a seamless structure.

18. The magnetic storage system according to claim 5, wherein the maximum distance between the bottom disk of the aforementioned number of disks that is closest to the base plate and the inner surface is 0.5 mm or more and 2.5 mm or less.

19. Each of the grooves defines a recess in the base plate, The magnetic storage system according to claim 5, wherein the distance between the bottom disk of the quantity of disks closest to the base plate and the inner surface of the recess is greater than the distance between the bottom disk and any other portion of the inner surface.

20. A magnetic memory system, A certain number of disks configured to rotate around an axis, It's the base, A base plate comprising: an outer surface; an inner surface opposite to the outer surface, wherein the inner surface comprises a surface that at least partially defines an internal cavity and is substantially flat; and means for changing the thickness of the base plate, wherein the minimum thickness of the base plate is defined by the means for changing the thickness; A side wall extending from the base plate, A magnetic storage system comprising a base, which includes an internal cavity defined by the base plate and the side wall, and which receives the number of disks.

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