Disc hub for holding a magnetic recording medium for film thickness measurement

Abstract

A disc hub is configured to hold a magnetic recording medium, the magnetic recording medium including an annular shape and a layer configured for magnetic recording. The disc hub includes a base plate portion for supporting an inner diameter region of the magnetic recording medium and a stem portion on the base plate portion. The stem portion includes a frustoconical portion on the base plate portion and a top portion on the frustoconical portion. At least the top portion of the stem portion includes a material having a hardness less than a hardness of stainless steel. The disc hub can reduce surface damage (e.g., scratches) on a surface of the medium during medium testing.

Description

Technical Field

[0001] This disclosure generally relates to an information storage device, and particularly to a hub for holding a magnetic recording medium during a process of characterizing a lubricant film on a magnetic recording medium. Background Technology

[0002] Computer systems and various electronic devices can use magnetic storage devices to store data and information. To read and / or write data, magnetic storage drives (e.g., hard disk drives) can employ a recording head (e.g., a slider) that flies very close to the surface of the magnetic recording medium. The magnetic recording medium can have a lubricant film formed on its surface to protect the magnetic recording medium and the recording head (e.g., to prevent potential contact events between them). In some examples, the lubricant film can be formed from lubricants, such as perfluoropolyether (PFPE) lubricants. PFPE lubricants can provide excellent tribological and contamination robustness for hard disk media applications. The thickness of the lubricant film is often a parameter of concern in the manufacturing process of magnetic recording media (e.g., the lubrication process). In some examples, controlling the PFPE lubricant film thickness to the tenth of an angstrom level can be helpful. Summary of the Invention

[0003] The following is a simplified summary of some aspects of this disclosure to provide a basic understanding of these aspects. This invention is not a broad overview of the features contemplated by this disclosure, nor is it intended to identify all essential or key elements of all aspects of this disclosure, nor to indicate the scope of any or all aspects of this disclosure. Its purpose is merely to present various concepts of some aspects of this disclosure in a simplified form as a prelude to the more detailed description that follows.

[0004] One aspect of this disclosure provides a hub for holding a magnetic recording medium, the magnetic recording medium comprising an annular shape and layers configured for magnetic recording. The hub includes a base plate portion for supporting an inner diameter region of the magnetic recording medium and a rod portion on the base plate portion. The rod portion includes a truncated conical portion on the base plate portion and a top portion on the truncated conical portion. At least the top portion of the rod portion comprises a material with a hardness less than that of stainless steel.

[0005] One aspect of this disclosure provides an apparatus for characterizing a magnetic recording medium for a data storage device. The apparatus includes a hub configured to hold and allow the magnetic recording medium to rotate to one or more positions. The hub includes a base plate portion for supporting an inner diameter region of the magnetic recording medium. The hub also includes a rod portion on the base plate portion. The rod portion includes a truncated conical portion on the base plate portion and a top portion on the truncated conical portion. At least the top portion of the rod portion comprises a material with a hardness less than that of stainless steel. The apparatus further includes a measuring component configured to measure the thickness of at least one film on the data recording surface of the magnetic recording medium at one or more locations.

[0006] One aspect of this disclosure provides a method for manufacturing a hub for holding a magnetic recording medium comprising an annular shape and layers configured for magnetic recording. The method uses a thermoplastic polymer to form the hub by providing a base plate portion for supporting the inner diameter of the magnetic recording medium and a rod portion on the base plate portion. The rod portion comprises a truncated conical portion on the base plate portion and a top portion on the truncated conical portion.

[0007] These and other aspects of this disclosure will become more fully understood by reading the following detailed description. Other aspects, features, and implementations of this disclosure will become more apparent to those skilled in the art by reading the following description of specific implementations of this disclosure in conjunction with the accompanying drawings. While features of this disclosure are discussed with respect to certain implementations and the following drawings, all implementations of this disclosure may include one or more of the advantages discussed herein. In other words, while one or more implementations may be discussed as having certain advantageous features, one or more of these features may also be used according to the various implementations of this disclosure discussed herein. Similarly, while some implementations may be discussed below as apparatus, system, or method implementations, it should be understood that these implementations can be implemented as various apparatuses, systems, and methods. Attached Figure Description

[0008] Figure 1 This is a top view schematic diagram of a disk drive comprising a slider and a magnetic recording medium configured for magnetic recording according to one aspect of this disclosure.

[0009] Figure 2 It is based on one aspect of this disclosure. Figure 1 A side view of the slider and magnetic recording medium.

[0010] Figure 3 This is a side view schematic diagram of a magnetic recording medium according to one aspect of this disclosure.

[0011] Figure 4 This is a conceptual block diagram of an apparatus for measuring the film thickness of a lubricant layer on a magnetic recording medium, according to one aspect of this disclosure.

[0012] Figure 5 This is a conceptual illustration of one aspect of this disclosure. Figure 4 An illustration of the surface of the magnetic recording medium shown.

[0013] Figure 6 It is an illustration providing a top view and a side view of a hub according to one or more aspects of this disclosure.

[0014] Figure 7 This is a flowchart illustrating a process for measuring the thickness of a lubricant film in a magnetic recording medium, according to some aspects of this disclosure.

[0015] Figure 8 This is a flowchart illustrating the process of manufacturing a disc hub according to some aspects of this disclosure. Detailed Implementation

[0016] In the following detailed description, reference is made to the accompanying drawings, which form part of the detailed description. Other aspects, features, and characteristics will become apparent from the accompanying drawings and the following detailed description, in addition to the illustrative aspects, features, and characteristics described above. The description of elements in each drawing may refer to elements in preceding drawings. The same reference numerals may refer to the same elements in multiple drawings, including alternative aspects of the same elements.

[0017] This disclosure relates in some aspects to a disk hub for holding and positioning a magnetic recording medium, and a method for characterizing a film on the magnetic recording medium using the disk hub. Magnetic recording media can be used in various data storage devices, such as hard disk drives.

[0018] Figure 1This is a top view schematic of a data storage device 100 (e.g., a disk drive or magnetic recording device) configured for magnetic recording according to one or more aspects of this disclosure, comprising a slider 108 and a magnetic recording medium 102. The data storage device 100 may include one or more disks / mediums 102 for storing data. The disks / mediums 102 are located on a spindle assembly 104, which is mounted to a drive housing 106. Data may be stored or recorded along tracks in the magnetic recording layer of the disk 102. Reading and writing data is accomplished using a recording head 108 (slider), which may have both a writing element (e.g., writer 108a) and a reading element (e.g., reader 108b). The writing element 108a is used to modify the properties of the magnetic recording layer of the disk 102 and thereby write information to it. In one aspect, the head 108 may have a magnetoresistive (MR)-based element (such as a tunneling magnetoresistive (TMR) element) for reading and a write pole with a coil that can be energized for writing. In operation, a spindle motor (not shown) rotates the spindle assembly 104, thereby rotating the disk 102 to position the head 108 at a specific location along the desired disk track 107. The positioning of the head 108 relative to the disk 102 can be controlled by control circuitry 110 (e.g., a microcontroller). Some embodiments of the data storage device 100 are HAMR (heat-assisted magnetic recording), EAMR (energy-assisted magnetic recording), or non-EAMR magnetic data recording systems, incorporating perpendicular magnetic recording (PMR) and shingled magnetic recording (SMR) disk drives or magnetic tape drives.

[0019] Figure 2 Based on one or more aspects of this disclosure Figure 1 A side view schematic diagram of the slider 108 and the magnetic recording medium 102. The magnetic recording medium 102 may have a lubricant layer (e.g., Figure 3 The lubricant layer 316 is shown. The slider 108 includes a writing element (e.g., a writer) 108a and a reading element (e.g., a reader) 108b positioned along the air bearing surface (ABS) 108c of the slider to write information to and read information from the medium 102, respectively.

[0020] Figure 3This is a side view schematic diagram of a magnetic recording medium 300 according to one aspect of the present disclosure. In some embodiments, the magnetic recording medium 300 may be configured for PMR. In other embodiments, the structures, systems, and / or methods described herein (for measuring lubricant thickness) may be used with other media types, including media configured for SMR, MAMR, or HAMR. The magnetic recording medium 300 has a stacked structure having a substrate 302 at a bottom / base layer, an amorphous soft magnetic underlayer (SUL) 304 on the substrate 302, a seed layer 306 on the SUL 304, an intermediate layer 308 on the seed layer 306, a bottom layer 310 on the intermediate layer 308, a magnetic recording layer (MRL) 312 on the bottom layer 310, and an overlayer 314 on the MRL 312. In some embodiments, the medium 300 may have a lubricant layer 316 on the overlayer 314. In some aspects, the substrate 302 may be made of one or more materials, such as Al alloys, NiP-plated Al, glass, glass ceramics, and / or combinations thereof. In one embodiment, substrate 302 may be a rigid substrate (e.g., glass or ceramic).

[0021] In some aspects, the amorphous SUL 304 can be made of a material (such as CoFe) having high permeability, high saturation magnetization, and low coercivity, and one or more elements selected from the group consisting of Mo, Nb, Ta, W, B, Zr, and combinations thereof. In some aspects, the seed layer 306 can be made of any suitable material known in the art. The seed layer 306 has certain lattice structures and crystallographic orientations that determine the crystallographic orientation of the layer grown / deposited on it (e.g., the intermediate layer 308). In one embodiment, the seed layer 306 can be made of a Ni alloy. In some aspects, the MRL 312 can be made of a CoPt alloy with or without additional elements or oxides. In some aspects, the MRL 312 can be made of FePt or an alloy selected from FePtX, where X is a material selected from Cu, Ni, and combinations thereof. In some examples, the crystallographic orientation of the MRL 312 can promote PMR, SMR, MAMR, or HAMR. In some aspects, the overlayer 314 can be made of carbon.

[0022] As used herein, the terms “above,” “below,” “up,” and “between” refer to the relative position of a layer with respect to other layers. Thus, a layer deposited or disposed on, above, or below another layer may be in direct contact with other layers or may have one or more intermediate layers. Furthermore, a layer deposited or disposed between multiple layers may be in direct contact with said multiple layers or may have one or more intermediate layers.

[0023] The lubricant layer 316 can provide protection for the magnetic recording medium 300 and / or the slider 108 during read / write operations when the slider 108 flies over the surface of the magnetic recording medium 300 at a close distance (e.g., as small as about 1 nm). In some aspects, the lubricant layer 316 can be made of polymer-based or liquid lubricants, such as linear perfluoropolyether (PFPE) lubricants, which provide excellent tribological and contamination robustness for the magnetic recording medium. The thickness of the lubricant layer 316 (e.g., a PFPE lubricant film) can be an important parameter in the manufacturing process of the magnetic recording medium 300 (e.g., the lubrication process). For example, the thickness of the lubricant layer 316 may need to be controlled to as small as one-tenth of an angstrom. Scale level.

[0024] Several techniques exist for measuring the thickness of PFPE lubricant films, such as FTIR (Fourier Transform Infrared Spectroscopy), ESCA (Electron Spectroscopy for Chemical Analysis), XRR (X-ray Reflectance), and ellipsometry. FTIR is particularly suitable for the production of magnetic media due to its ease of handling, rapid analysis, and robustness to harsh environments. For example, FTIR testing can be used to determine the thickness of lubricant layer 316 (e.g., PFPE lubricant film) based on the spectral characteristics obtained from FTIR testing.

[0025] Figure 4 This is a conceptual block diagram illustrating an apparatus 400 for measuring the film thickness of a lubricant layer according to one aspect of this disclosure. Apparatus 400 may include a hub 402 mounted on an FTIR testing apparatus 404. A magnetic recording medium 406 may be used, for example, during a lubrication process (e.g., in the manufacture of magnetic recording media such as...). Figure 3 After being loaded onto the disk hub 402, the magnetic recording medium (one of the final steps in the process) is used. In one example, the magnetic recording medium 406 can be associated with... Figure 3 The magnetic recording medium 300 described is the same. The FTIR testing apparatus 404 may have an infrared (IR) source 408, which can generate and face the surface of the magnetic recording medium 406 (e.g., Figure 4 An IR beam 410 is output from the bottom surface of the magnetic recording medium 300. The IR beam 410 is reflected by the bottom surface (e.g., or top surface, on which an arbitrary surface with a lubricant layer is disposed) of the magnetic recording medium 406 and can be detected by an IR detector 412 for signal processing and analysis using a measurement assembly 414 (e.g., an FTIR processing unit). The film thickness of the lubricant layer on the bottom surface of the magnetic recording medium 300 can be characterized or measured by the reflected IR beam 410, for example, proportional to the intensity of the reflected IR beam. In one example, the FTIR processing unit 414 can determine the film thickness of the lubricant layer based on a pre-established calibration curve between IR reflection and film thickness.

[0026] In one example, film thickness data can be collected at multiple locations on the media surface (e.g., at four points spaced 90 degrees apart) to determine whether the lubricant layer is uniformly applied to the surface of the magnetic recording medium 406. For this purpose, the magnetic recording medium 406 can be rotated around a hub 402 during FTIR testing, such that the IR beam 410 can be reflected from different locations on the bottom surface of the recording medium 406. In some examples, the hub 402 can be made of a metal suitable for cleanroom operation (e.g., stainless steel). However, a metal hub may easily scratch the surface of the magnetic recording medium 406 during FTIR testing. For example, scratches can form on the bottom surface of the recording medium 406 as the medium rotates around the hub. Test results have shown that stainless steel hubs can result in an undesirably high rate of surface scratches (e.g., 10% to 25%) on the medium measured by FTIR.

[0027] Figure 5 The diagram illustrates when the medium is installed... Figure 4 The illustration shows the bottom surface of the magnetic recording medium 406 on the hub 402 as described. In some examples, the magnetic recording medium 406 has an annular shape and layers configured for magnetic recording (e.g., MRL312). When a metal (e.g., stainless steel) hub is used to hold and retain the magnetic recording medium 406 during FTIR testing, surface damage (e.g., scratches) may occur on the surface of the medium. Scratches typically occur in the inner diameter region between the inner diameter (ID) of the opening 502 and the intermediate diameter (MD) of the magnetic recording medium. The MD can be located anywhere between the ID and the outer diameter (OD) of the magnetic recording medium. Additionally, scratches or damage may occur anywhere between the ID and OD of the magnetic recording medium. Surface damage can be caused by accidental surface contact between the magnetic recording medium 406 and the hub 402 when the magnetic recording medium is mounted on the hub 402. Furthermore, any rotation of the magnetic recording medium 406 about the hub 402 may occur in the disk-to-hub contact area of ​​the magnetic recording medium 406 (e.g., Figure 5 Scratches (e.g., annular scratches) are introduced into region 504 of the magnetic recording medium. Scratches may produce tiny particles, which reduce the reliability of the magnetic recording medium 406.

[0028] Figure 6 This is an illustration of a side view and a top view of a hub 600 according to one or more aspects of this disclosure. The hub 600 can be used with respect to... Figure 4 The hub 402 described is identical. Hub 600 has certain features that can reduce surface damage on the magnetic recording medium during FTIR testing and film thickness measurement. In some examples, hub 600 can reduce the medium scratch rate by about 15 percent, resulting in an increase in yield of about 0.02 percent.

[0029] The hub 600 differs from typical hubs (e.g., metal hubs) in shape and material to reduce potential surface damage to the magnetic recording medium during FTIR testing. In some embodiments, the hub 600 may have a height between about 12 mm and about 30 mm (inclusive). Figure 6 (H1 in the original text). On the other hand, the hub 600 has a base plate portion 602 and a rod portion 604 on the top side of the base plate portion 602. The rod portion 604 extends in a height direction that is substantially perpendicular to the top side of the base plate portion 602. In one embodiment, the rod portion 604 has a top portion 606 and a truncated tapered portion 608. The top portion 606 has a top surface 610 (e.g., a flat surface) and a curved surface 612 extending between the top surface 610 and the truncated tapered portion 608.

[0030] In one embodiment, the rod portion 604 further includes a cylindrical portion 614 on the base plate portion 602. A truncated conical portion 608 extends between the top portion 606 and the cylindrical portion 614. In some embodiments, the cylindrical portion 614 may have a height between about 0.5 mm and about 5 mm (inclusive). Figure 6 (H2 in the original text). The base plate portion 602 forms the bottom or base of the hub 600 to support and hold the magnetic recording medium during FTIR testing. In some embodiments, the base plate portion 602 may have a thickness of approximately 1.1 mm. Figure 6 (H3 in the text). During FTIR testing and film thickness measurement, the magnetic recording medium 406 is positioned on the base plate portion 602, and the rod portion 604 passes through the opening 502 of the magnetic recording medium 406 (see H3 in the text). Figure 5 ).

[0031] On the other hand, the curved surface 612 is formed by a smooth, sloping edge or a chamfer with an appropriate radius (e.g., between about 5 mm and about 10 mm, including the end value). The curved surface 612 removes sharp edges on the top portion, such that potential damage to the medium surface (e.g., surface scratches) can be reduced or avoided if the magnetic recording medium is accidentally struck by the top portion 606 of the hub during FTIR testing, because the curved surface 612 reduces the impact force on the magnetic recording medium. In some embodiments, the curved surface 612 may be formed by one or more smooth surfaces that may have the same or different radii. In some embodiments, the curved surface 612 may not have a fixed radius. In some embodiments, the curved surface 612 may be replaced by a plurality of flat surfaces joined together without forming any sharp angles.

[0032] On the other hand, the truncated conical portion 608 may have different diameters (or radii) at different distances from the base plate portion 602. For example, the truncated conical portion 608 has a first diameter near a first end close to the cylindrical portion 614 and a second diameter near a second end close to the top portion 606 (e.g., the curved surface 612). The diameter of the truncated conical portion 608 may gradually change from the first diameter to the second diameter. The first diameter (lower diameter) may be equal to or greater than the second diameter (upper diameter). The cylindrical portion 614 may have a fixed diameter (…). Figure 6 D1 in the figure is equal to the maximum diameter (e.g., the lower diameter) of the truncated conical portion 608.

[0033] The base plate portion 602 may have a diameter ( Figure 6 The diameter D2 of the magnetic recording medium is appropriately sized to improve the stability of the magnetic recording medium when rotated to different angles or positions during FTIR testing and film thickness measurement. In one example, an operator may use clamps (or the like) to hold the outer edge of the magnetic recording medium in order to rotate it. In some embodiments, the base plate portion 602 may have a diameter between about 27 mm and about 30 mm (inclusive). In one example, the diameter of the base plate portion 602 may be about 28.3 mm. In some embodiments, the diameter D2 of the base plate portion 602 may be larger than the diameter D1 of the cylindrical portion 614 or the truncated conical portion 608, for example, by about 2.2 mm to about 5.2 mm.

[0034] To further reduce potential media surface damage due to any contact between the media surface and the hub, the hub 600 is made of a soft and chemically stable material (e.g., a thermoplastic polymer). When the hub is made of a material softer than metal (e.g., stainless steel), media surface damage due to contact between the hub and the magnetic recording medium can be reduced or avoided. In some embodiments, the hub may be made of a thermoplastic polymer, for example, from the polyaryletherketone (PAEK) family, which can be used in various engineering applications. The PAEK family may include polyetherketone (PEK), polyetherketoneketone (PEKK), polyetheretherketoneketone (PEEKK), polyetherketoneketone (PEKEKK), and polyetheretherketone (PEEK). In one example, the hub 600 may be made of PEEK material. Compared to other materials in the PAEK family, PEEK provides a suitable combination of properties for use as a material in the manufacture of hub 600, which is typically used in cleanroom environments. For example, PEEK has a suitable combination of fatigue resistance and chemical resistance, and good frictional and abrasion resistance properties. PEEK also possesses low moisture absorption, indeterminate dielectric (insulating) properties, good dimensional stability, and inherently low flammability. Furthermore, PEEK materials exhibit crystalline properties, which are desirable for discs used in FTIR testing in cleanroom settings.

[0035] With the aforementioned properties, PEEK discs can provide stable performance over extended periods in FTIR testing applications. For example, PEEK discs can maintain FTIR measurement accuracy over long periods by effectively eliminating or reducing corrosion, wear, friction, and degassing contaminants from the disc. PEEK material is also versatile, allowing for the formation of complex disc geometries (e.g., molding) without the labor-intensive post-processing steps required for manufacturing metal discs. This, in turn, helps reduce the cost of manufacturing PEEK discs.

[0036] Figure 7 This is a flowchart illustrating a process 700 for measuring the film thickness of a magnetic recording medium using a hub 600 according to some aspects of this disclosure. In one example, process 700 may be used to measure the lubricant film thickness of a magnetic recording medium 300 or 406 using apparatus 400. At block 702, the magnetic recording medium may be mounted on the hub of an FTIR testing apparatus, and the magnetic recording medium has at least one film (e.g., lubricant layer 316) on its surface. For example, the testing apparatus may be as described above. Figure 4 The described FTIR measuring device 400. The hub can be used with... Figure 6The described hub 600 is identical. In one example, the hub may be made of a soft material (e.g., PEEK) and have a smooth top surface or shape that reduces potential surface damage to the magnetic recording medium during the FTIR measurement process and manipulation. In block 704, the magnetic recording medium is rotated to one or more positions (e.g., angular positions). For example, the magnetic recording medium may be rotated around the hub by a person or machine using clamps to hold the outer edge of the magnetic recording medium. In block 706, the device 400 may measure the thickness of at least one film (e.g., a lubricant film) at one or more locations.

[0037] In one embodiment, the process may perform a sequence of actions in a different order. In another embodiment, the process may skip one or more actions. In still other embodiments, one or more actions may be performed simultaneously. In some embodiments, additional actions may be performed.

[0038] Figure 8 This is a flowchart illustrating a process 800 for manufacturing a hub according to some aspects of this disclosure. Process 800 can be used to manufacture the hub 600 described above for holding a magnetic recording medium during FTIR testing. In one embodiment, the method can use a soft material to form the hub, such as a thermoplastic polymer (e.g., PEEK). At block 802, the method manufactures the hub to provide a base plate portion for supporting an inner diameter region of the magnetic recording medium. At block 804, the method manufactures the hub to provide a rod portion on the base plate portion. The rod portion includes a frustoconical portion on the base plate portion and a top portion on the frustoconical portion. In some embodiments, the hub can be made of a material selected from the group consisting of PEK, PEKK, PEEKK, PEKEKK, and PEEK.

[0039] As used herein, the terms “above,” “below,” and “between” refer to the relative position of a layer with respect to other layers. Thus, a layer deposited or disposed above or below another layer may be in direct contact with other layers or may have one or more intermediate layers. Furthermore, a layer deposited or disposed between multiple layers may be in direct contact with said multiple layers or may have one or more intermediate layers.

[0040] Those skilled in the art will understand from this disclosure that while various exemplary manufacturing methods are discussed herein with reference to magnetic recording discs, methods with or without modification can be used to manufacture other types of recording discs, such as optical recording discs (e.g., compact discs (CDs) and digital multifunction discs (DVDs)), or magneto-optical recording discs, or ferroelectric data storage devices.

[0041] While the foregoing description includes many specific embodiments of the invention, these should not be construed as limiting the scope of the invention, but rather as examples of specific embodiments. Therefore, the scope of the invention is not determined by the described embodiments, but by the appended claims and their equivalents.

Claims

1. A hub for holding a magnetic recording medium during FTIR testing, the magnetic recording medium comprising an annular shape and layers configured for magnetic recording, the hub comprising: The base plate portion is used to support the inner diameter region of the magnetic recording medium during the FTIR test; as well as The rod portion on the base plate portion, wherein the base plate portion and the rod portion are integrally formed, the rod portion comprising: The truncated conical portion on the base plate portion; and The top portion of the truncated conical section At least the top portion of the rod portion comprises a material with a hardness less than that of stainless steel; and The FTIR test is used to determine the thickness of at least one film on the data recording surface of the magnetic recording medium based on the spectral characteristics obtained by the FTIR test.

2. The disc hub according to claim 1, wherein the material comprises thermoplastic or polyaryletherketone (PAEK) polymer.

3. The disc hub according to claim 2, wherein the material is selected from the group consisting of: polyetherketone (PEK), polyetherketoneketone (PEKK), polyetheretherketoneketone (PEEKK), polyetherketoneketone (PEKEKK), polyetheretherketoneketone (PEEKK), and combinations thereof.

4. The hub according to claim 3, wherein the material comprises PEEK.

5. The hub according to claim 1, wherein the diameter of the base plate portion is between 27 mm and 30 mm, inclusive.

6. The hub according to claim 5, wherein the diameter of the base plate portion is 28.6 mm and the thickness of the base plate portion is 1.1 mm.

7. The hub according to claim 1, wherein the rod portion further comprises: The cylindrical portion between the base plate portion and the truncated conical portion.

8. The hub according to claim 7, wherein the diameter of the cylindrical portion is 2.2 mm to 5.2 mm smaller than the diameter of the base plate portion.

9. The hub of claim 7, wherein the truncated conical portion includes a first end extending into the cylindrical portion and a second end extending into the top portion, wherein the diameter of the first end is greater than the diameter of the second end.

10. The hub of claim 1, wherein the top portion includes a top surface and a curved surface extending between the top surface and the truncated tapered portion.

11. The hub of claim 10, wherein the radius of the curved surface is between 5 mm and 10 mm, inclusive.

12. An apparatus for characterizing a magnetic recording medium for a data storage device, comprising: A disk hub configured to hold and allow the magnetic recording medium to rotate to one or more positions during FTIR testing, wherein the disk hub comprises: The base plate portion is used to support the inner diameter region of the magnetic recording medium during the FTIR test; and The rod portion on the base plate portion, wherein the base plate portion and the rod portion are integrally formed, the rod portion comprising: The truncated conical portion on the base plate; and The top portion of the truncated conical portion, wherein at least the top portion of the rod portion comprises a material with a hardness less than that of stainless steel; and A measuring component configured to measure the thickness of at least one film on the data recording surface of the magnetic recording medium at the one or more locations; and The FTIR test is used to determine the thickness of the at least one film based on the spectral characteristics obtained by the FTIR test.

13. The device of claim 12, wherein the material comprises thermoplastic or polyaryletherketone (PAEK) polymer.

14. The device according to claim 13, wherein the material is selected from the group consisting of: polyetherketone (PEK), polyetherketoneketone (PEKK), polyetheretherketoneketone (PEEKK), polyetherketoneketone (PEKEKK), polyetheretherketoneketone (PEEKK), and combinations thereof.

15. The device of claim 14, wherein the material comprises PEEK.

16. The device of claim 12, wherein the diameter of the base plate portion is between 27 mm and 30 mm, including the end value.

17. The device of claim 16, wherein the diameter of the base plate portion is 28.6 mm and the thickness of the base plate portion is 1.1 mm.

18. The device of claim 12, wherein the rod portion further comprises: The cylindrical portion between the base plate portion and the truncated conical portion.

19. The device of claim 18, wherein the diameter of the cylindrical portion is smaller than the diameter of the base plate portion.

20. The device of claim 18, wherein the truncated conical portion includes a first end extending into the cylindrical portion and a second end extending into the top portion, wherein the diameter of the first end is greater than the diameter of the second end.

21. The device of claim 12, wherein the top portion includes a top surface and a curved surface extending between the top surface and the truncated tapered portion.

22. The device of claim 21, wherein the radius of the curved surface is between 5 mm and 10 mm, including the end value.

23. A method of manufacturing a hub for holding a magnetic recording medium during FTIR testing, the magnetic recording medium comprising an annular shape and layers configured for magnetic recording, the method comprising: The disc hub is formed using a thermoplastic polymer, including, A base plate portion is provided for supporting the inner diameter of the magnetic recording medium during the FTIR test; and A rod portion is provided on the base plate portion, the base plate portion and the rod portion are integrally formed, wherein the rod portion includes: The truncated conical portion on the base plate; and The top portion of the truncated conical section; and The FTIR test is used to determine the thickness of at least one film on the data recording surface of the magnetic recording medium based on the spectral characteristics obtained by the FTIR test.

24. The method of claim 23, wherein the thermoplastic polymer is selected from the group consisting of: polyetherketone (PEK), polyetherketoneketone (PEKK), polyetheretherketoneketone (PEEKK), polyetherketoneketone (PEKEKK), polyetheretherketoneketone (PEEKK), and combinations thereof.

25. The method of claim 24, wherein the thermoplastic polymer comprises PEEK.

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