JP2007099279A - Disk accommodating body and disk accommodating case - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a disk accommodating body and a disk accommodating case capable of reliably preventing any trouble attributable to deposition of particles on a surface of a disk by preventing the particles from generating. <P>SOLUTION: In the disk accommodating body 1, a plurality of insertion grooves 38 with an outer peripheral end part 26 of a magnetic recording disk 2 inserted therein are formed at a predetermined spacing on the inner side of the disk accommodating case 3. In a condition that the magnetic recording disk 2 is inserted in the insertion grooves 38, chamfered portions 262 and 263 of the outer peripheral end part 26 are respectively brought into contact with inclined surface portions 382 and 383 of the insertion grooves 38. The inclined surface portions 382 and 383 are formed in a mirror face by the polishing, and the surface roughness Ra thereof is less than the surface roughness Ra of the outer peripheral end part 26. Thus, no dust is generated even when the inclined surface portions 382 and 383 are rubbed by the outer peripheral end part 26 of the magnetic recording disk 2. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a disk storage body in which a magnetic recording disk (including a magneto-optical recording disk) or an intermediate product thereof is stored in a disk storage case, the disk storage case, and a method of manufacturing the disk storage case.

A magnetic recording disk has a structure in which at least an underlayer, a magnetic layer, a protective layer, and a lubricating layer are laminated on the surface of a nonmagnetic substrate. In such a magnetic recording disk, a convex portion formed by particles on the surface. Is known to have a negative effect on electromagnetic conversion as a result of thermal asperity, which generates heat in the magnetoresistive head and fluctuates the resistance value of the head. With regard to particles that cause such thermal asperity, the present inventor puts the magnetic recording disk or a product in the middle of its manufacture into or out of a disk storage case made of polycarbonate or the like, and stores them in the disk storage case 3. Obtained knowledge that the inner circumferential surface of the disk storage case and the end surface of the disk come into contact with each other during transport, and that particles generated from the end surface adhere to the surface of the magnetic recording disk or a product that is being manufactured. Has a surface roughness Ra of less than 1 μm and further a mirror surface of 0.5 μm or less (see Patent Document 1).
Japanese Patent No. 3527075

  However, as described in Patent Document 1, there is a problem that even when the surface roughness Ra of the end of the disk is reduced, the generation of particles cannot be completely prevented. The defects caused by the particles are not limited to thermal asperity when a magnetoresistive head (MR head) or a large magnetoresistive head (GMR head) is used. The wear dust is scraped up and transferred to and deposited on the magnetic head to cause fly stiction failure. Such fly stiction failure is the reliability of HDI (Head-Disk-Interface). It will cause the decrease.

  In view of the above problems, an object of the present invention is to provide a disk storage body and a disk storage case capable of reliably preventing the occurrence of defects caused by particles adhering to the disk surface by preventing the generation of particles. Is to provide.

  As a result of various studies on the above problems, the present inventor has found that the reason why the generation of particles cannot be completely prevented even if the surface roughness Ra of the end surface of the disc is reduced is that the disc storage case is related to particles. We obtained new knowledge that it was because no improvement was made. In other words, if the disc storage case rubs between the end surface of the disc and the end surface of the disc in a state where the disc is stored in the disc storage case, dust is generated in the disc storage case, and particles are attached to the surface of the disc. I got it.

  The present invention has been made based on such knowledge. In the present invention, a magnetic recording disk in which at least an underlayer, a magnetic layer, a protective layer, and a lubricating layer are laminated on the surface of a nonmagnetic substrate, or a product in the middle of its manufacture. And a disk storage case having a disk support portion that supports the disk in contact with the end portion of the disk, the surface roughness Ra of the disk support portion is set to the end portion of the disk. It is characterized by being made smaller than the surface roughness Ra.

  In the present invention, the “intermediate product” means to include a non-magnetic substrate such as a glass substrate in which a thin film layer such as an underlayer is not formed on the surface.

  In the present invention, since the surface roughness Ra of the disk support portion is smaller than the surface roughness Ra of the end portion of the disk, when the disk is put in and out of the disk storage case, the disk is further stored in the disk storage case. When transported by, the disc support portion of the disc storage case and the end surface of the disc rub against each other, so the friction is small, so that no dust is generated at the disc support portion. Therefore, it is possible to prevent particles from adhering to the disk surface.

  The present invention can be applied to the case where the disc support portion supports either the outer peripheral end portion of the disc or the inner peripheral end portion of the center hole. However, the disc support portion supports the outer peripheral end portion of the disc. It is preferable to adopt.

  The present invention is effective when applied to the case where the non-magnetic substrate is a glass substrate. That is, since the glass substrate is superior in strength and flatness to a metal substrate such as aluminum, the non-magnetic substrate is being switched from the metal substrate to the glass substrate, but the glass substrate has a high hardness. For this reason, when a glass substrate is used, the disk case tends to be cut more easily than when a metal substrate is used. However, in the present invention, since the surface roughness Ra of the disk support portion is smaller than the surface roughness Ra of the end portion of the disk, particles are not generated even if the disk support portion is rubbed. Therefore, even when a glass substrate is used as the nonmagnetic substrate, the generation of particles from the disk case can be prevented, and the occurrence of defects due to the particles can be reliably prevented.

  The present invention is effective when applied to a case where the disk is a magnetic recording disk as a finished product. Since the magnetic recording disk is inspected in the middle of its manufacture, even if particles are generated in the middle of production, it can be found in the middle of inspection, but if particles are generated in the middle of transporting the magnetic recording disk as a finished product, After the magnetic recording disk is mounted on the disk drive, a problem occurs. Therefore, when the present invention is applied to a disk storage body in which a magnetic recording disk as a finished product is stored in a disk storage case, generation of particles during transportation can be prevented, and after the magnetic recording disk is mounted on a disk drive device, It is possible to prevent problems from occurring.

  In the present invention, it is possible to employ a configuration in which the disc support portion supports at least two portions in the circumferential direction among the end portions of the disc. Since the generation of particles from the disc case can be prevented when the contact portion between the end portion of the disc and the disc support portion is smaller, the disc support portion supports two places in the circumferential direction among the end portions of the disc. It is preferable to adopt the configuration.

  In the present invention, the surface roughness Ra of the end portion of the disk is, for example, 1 μm or less. Further, the surface roughness Ra of the end portion of the disk is further preferably 0.5 μm or less, and more preferably, the surface roughness Ra of the outer peripheral end portion of the disk is preferably 0.05 μm or less. . In either case, in the present invention, the surface roughness Ra of the disk support portion is made smaller than the surface roughness Ra of the end portion of the disk.

  In the present invention, a magnetic recording disk in which at least an underlayer, a magnetic layer, a protective layer, and a lubricating layer are laminated on the surface of a nonmagnetic substrate, or a disk that supports the disk in contact with the end of a disk that is in the process of being manufactured. In the disc storage case provided with the support portion, at least a region including the disc support portion is polished.

  In the disc storage body and the disc storage case according to the present invention, the surface roughness Ra of the disc support portion is smaller than the surface roughness Ra of the end portion of the disc, so that the disc support portion of the disc storage case and the end surface of the disc are rubbed. However, particles are not generated from the disk support portion. Therefore, it is possible to reliably prevent particles from adhering to the surface of the disk.

  Embodiments of the present invention will be described below with reference to the drawings.

(Overall configuration of disc housing)
FIG. 1 is a schematic perspective view showing a disk storage case to which the present invention is applied. 2A and 2B are a front view of a disk storage case to which the present invention is applied, and a cross-sectional view taken along line II ′.

  As shown in FIG. 1 and FIGS. 2 (a) and 2 (b), a disk storage body 1 to which the present invention is applied includes a disk and a disk storage case 3 in which a plurality of disks are stored. Here, the disk storage case 3 can store either the magnetic recording disk 2 as a completed product or a product in the process of manufacturing as a disk. In the following description, the disk is a magnetic recording disk as a completed product. The case of 2 will be described. Note that the “intermediate product” means to include a nonmagnetic substrate such as a glass substrate on which a thin film layer such as an underlayer described below is not formed.

(Configuration of magnetic recording disk 2)
The magnetic recording disk 2 has a structure in which at least an underlayer, a magnetic layer, a protective layer, and a lubricating layer are laminated in this order on the surface of a circular nonmagnetic substrate having a center hole 21. The nonmagnetic substrate is made of, for example, chemically strengthened glass such as aluminosilicate glass, and the surface of the nonmagnetic substrate is mirror-polished so that the surface roughness Ra is 0.3 nm or less and the Rmax is 3 nm or less. ing. Further, the inner peripheral end and the outer peripheral end of the nonmagnetic substrate are each chamfered, and such a shape remains as it is in the state of the magnetic recording disk 2. As shown in FIG. 2B, the outer peripheral end portion 26 is formed with an outer peripheral wall surface 261 and chamfered portions 262 and 263 formed by chamfering on both sides thereof. Here, the outer peripheral wall surface 261 and the chamfered portions 262 and 263 are rubbed when the magnetic recording disk 2 is put in and out of the disk storage case 3 or when the magnetic recording disk 2 is transported in the state of being stored in the disk storage case 3. In order to prevent generation of particles, it is precisely polished by mechanical polishing or the like (brush, pad), and has a mirror surface with a surface roughness Ra of 1 μm or less. In addition, the outer peripheral wall surface 261 and the chamfered portions 262 and 263 may be mirror surfaces having a surface roughness Ra of 0.5 μm or less, or even 0.05 μm or less.

  Such mirror finishing may be performed after any of the steps of grinding and polishing the glass substrate as the nonmagnetic substrate, or after each step. Here, the steps of grinding and polishing the glass substrate are generally roughly divided into (1) roughing (rough grinding), (2) sanding (fine grinding, lapping), (3) first polishing (polishing), (4) It consists of each process of 2nd grinding | polishing (final grinding | polishing, polishing). Depending on the state of the surface before grinding, any or all of (1) roughening, (2) sanding, and (3) first polishing may be omitted. In addition, when a glass substrate is manufactured by a high precision press, it is not necessary to grind and polish. Further, the mechanical polishing of the outer peripheral edge portion 26 of the glass substrate is performed after the sanding (fine grinding, lapping) step, the first polishing (polishing) or the polishing in addition to the roughening (rough grinding) step, for example. You may perform after a 2nd grinding | polishing (final grinding | polishing, polishing) process.

  The structure of each thin film will be described below while explaining the outline of the process of manufacturing the magnetic recording disk 2 using such a nonmagnetic substrate. In order to manufacture the magnetic recording disk 2, first, a base layer is formed on the surface of the nonmagnetic substrate by sputtering or the like. The underlayer is, for example, a CrW thin film having a thickness of 10 nm, and is formed to improve the crystal structure of the magnetic layer. Next, a magnetic layer is formed on the upper layer of the base layer by sputtering or the like. The magnetic layer is made of, for example, a CoCrPtB alloy having a thickness of 15 nm, and the thickness is 15 nm. The contents of Co, Cr, Pt, and B in the magnetic layer 13 are, for example, Co: 62 at%, Cr: 20 at%, Pt: 12 at%, and B: 6 at%. Next, a protective layer is formed on the upper layer of the magnetic layer by sputtering. The protective layer is made of hydrogenated carbon having a thickness of 5 nm, for example, and has a function of improving the wear resistance and protecting the magnetic layer. Next, a lubricating layer is formed on the surface of the protective layer by an immersion film forming method. The lubrication layer has a function of mitigating the impact when it comes into contact with the magnetic head, and is composed of a thin bafluoropolyether layer having a thickness of 3 nm or less. Here, the lubricating layer tends to be thinned to 2 nm or less, for example, about 1.0 nm.

(Configuration of disc storage case 3)
In this embodiment, the magnetic recording disk 2 as a finished product is stored in the disk storage case 3 and transported in units of a plurality of sheets after various inspections are completed.

  In this embodiment, the disk storage case 3 is a rectangular frame that opens upward and downward, and the magnetic recording disk 2 can be taken in and out of the disk storage portion 32 inside the upper opening 31. The disk storage case 3 includes a pair of side plate portions 33 and 34 extending in parallel in the front-rear direction, and a pair of connecting plate portions 35 and 36 in the width direction connecting the respective end portions of the side plate portions 33 and 34. Thus, the dimension between the thin plate portions 331 and 341 is slightly larger than the outer diameter of the magnetic recording disk 2.

  As can be seen from FIG. 2A, each of the side plate portions 33 and 34 includes thin plate portions 331 and 341 in order from the upper side, and tapered portions 332 and 342 whose thickness gradually increases inward toward the lower side. Yes. A plurality of ribs 37 are formed on the inner surfaces of the side plate portions 33 and 34 so as to face each other. Each of the plurality of ribs 37 has a trapezoidal cross-sectional shape extending from the upper portion of the thin plate portions 331 and 341 to the tapered portions 332 and 342, and is formed on the inner surfaces of the side plate portions 33 and 34 at predetermined intervals in the front-rear direction. Has been. Accordingly, trapezoidal cross-section grooves are formed between the ribs 37, and these grooves function as insertion grooves 38 into which the outer peripheral end portion 26 of the magnetic recording disk 2 can be inserted.

  In this embodiment, when the magnetic recording disk 2 is inserted into the insertion groove 38 between the side plate portions 33 and 34 and the magnetic recording disk 2 is stored, the two chamfered portions 262 and 263 of the outer peripheral end portion 26 are respectively While the bottom portion of the insertion groove 38 is in contact with the slope portions 382 and 383 (disk support surfaces) on both sides sandwiching the insertion groove 38, the outer peripheral wall surface 261 of the outer peripheral end portion 26 is slightly from the bottom surface portion 381 of the insertion groove 38. Is in a floating state. Such a state is the same for the insertion groove 38 formed in any of the side plate portions 33 and 34, and the magnetic recording disk 2 is supported at two locations in the circumferential direction.

  In addition, flange portions 336 and 346 projecting outward are formed at the upper end portions of the side plate portions 33 and 34, which are gripped by a robot hand or the like, and a disk storage case 3 in which the magnetic recording disk 2 is stored. The (disk storage body 1) can be transported. Further, substantially U-shaped cutouts 351 and 361 are formed in the connecting plate portions 35 and 36, respectively. Accordingly, when the magnetic recording disk 2 is stored in the disk storage case 3, the central portion including the central hole 21 of the magnetic recording disk 2 is exposed from the notches 351 and 361.

  Further, in the disk storage case 3 of this embodiment, the slope portions 382 and 383 of the insertion groove 38 that are in contact with at least the outer peripheral end 26 of the magnetic recording disk 2 have a surface roughness Ra of the outer peripheral end of the magnetic recording disk 2 described above. Surface polishing is performed using a buffing machine or the like so as to be smaller than the surface roughness Ra of the portion 26. That is, even when the surface roughness Ra of the outer peripheral wall surface 261 and the chamfered portions 262 and 263 is formed on any mirror surface of 1 μm or less, 0.5 μm, or 0.05 μm or less, the surface roughness of the inclined surface portions 382 and 383 is increased. The depth Ra is smaller than the surface roughness Ra of the outer peripheral wall surface 261 and the chamfered portions 262 and 263.

(Manufacturing method of the disc storage case 3)
In manufacturing the disk storage case 3 of this embodiment, first, the disk storage case 3 is resin-molded using the above-described resin (resin molding process). In this resin molding step, it is possible to use general resins such as various polyolefins such as polyethylene and polypropylene, polyvinyl chloride, and Teflon (registered trademark / PTFE). In particular, when the disk storage case 3 is manufactured by a normal injection molding method, examples of the resin include polycarbonate, polyamide, thermotropic liquid crystal polymer (LCP), polyether ether ketone (PEEK), polyether ketone (PEK), PEEK alloy resin (for example, PEEK / thermotropic liquid crystal polymer, PEEK / polybenzimidazole (PBI), etc.), polybenzimidazole (PBI), polyphenylene sulfide (PPS), polyethersulfone (PES), polyetherimide (PEI) ), A fluororesin such as polytetrafluoroethylene (PTFE), or the like can be used.

  Next, in the disk storage case 3, the surfaces of the slope portions 382 and 383 of the insertion groove 38 are polished, and the slope portions 382 and 383 are mirror-finished (polishing process). In this polishing step, buffing is preferably performed. In this buffing, a buff made of a flexible material such as woven fabric or leather is used, and the abrasive is bonded to the buff or temporarily held as a buff abrasive. In this way, the buff is provided with a function as a polishing tool, and the buff that rotates at high speed is brought into pressure contact with the inclined portion of the insertion groove 38 of the disk storage case 3 for polishing.

(Main effects of this form)
As described above, in the disk housing 1 of the present embodiment, both the outer peripheral end portion 26 of the magnetic recording disk 2 and the slope portions 382 and 383 where the outer peripheral end portion 26 of the magnetic recording disk 2 contacts with the insertion groove 38 are both. It is a mirror surface, and the surface roughness Ra of the slope portions 382 and 383 is smaller than the surface roughness Ra of the outer peripheral end portion 26 of the magnetic recording disk 2. For this reason, when the magnetic recording disk 2 is inserted into the insertion groove 38 and after the insertion, even if vibration is applied, the frictional resistance generated between the inclined surface portions 382 and 383 and the outer peripheral end portion 26 is small. Even if the portions 382 and 383 and the outer peripheral end portion 26 of the magnetic recording disk 2 are rubbed, no wear powder is generated from either the inclined portion 382 or the outer peripheral end portion 26 of the magnetic recording disk 2. Therefore, even if the disk storage body 1 in which the magnetic recording disk 2 is stored in the disk storage case 3 is transported, particles that cause a decrease in the reliability of the HDI and the like may adhere to the surface of the magnetic recording disk 2. Absent.

  Further, in the present embodiment, since the present invention is applied to the disk storage case 3 that stores the magnetic recording disk 2 as a finished product, it is possible to reliably prevent problems caused by particles. That is, since the magnetic recording disk 2 is inspected in the middle of its manufacture, even if particles are generated in the middle of manufacture, it can be detected by the inspection in the middle. If this occurs, a defect will occur after the magnetic recording disk 2 is mounted on the disk drive. Therefore, when the present invention is applied to the disk storage body 1 in which the magnetic recording disk 2 as a finished product is stored in the disk storage case 3, the generation of particles in the middle of conveyance can be prevented, and the magnetic recording disk 2 becomes a disk drive device. It is possible to prevent problems from occurring after being installed.

  Further, in the present embodiment, since the present invention is applied to the disk storage case that stores the magnetic recording disk 2 whose nonmagnetic substrate is a glass substrate, problems caused by particles can be reliably prevented. That is, the glass substrate is superior in strength and flatness to a metal substrate such as aluminum, but has a high hardness. For this reason, when the glass substrate is used, the disk storage case 3 tends to be cut more easily than when the metal substrate is used. However, in the present invention, the surface roughness Ra of the inclined surface portions 382 and 383 as the disk support portions. However, since the surface roughness Ra of the outer peripheral end portion 26 of the magnetic recording disk 2 is smaller, the slope portions 382 and 383 and the outer peripheral end portion 26 of the magnetic recording disk 2 are not rubbed to generate particles. Therefore, even when a glass substrate is used as the nonmagnetic substrate, the generation of particles from the disk storage case 3 can be prevented, so that the occurrence of defects due to the particles can be reliably prevented.

(Other embodiments)
The technical scope of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention, and specific materials and configurations described in the embodiment. Is merely an example and can be changed as appropriate.

  For example, in the above embodiment, the example in which the magnetic storage disk 2 as a finished product is stored in the disk storage case 3 has been described. However, when the magnetic storage disk 2 is manufactured, the intermediate storage product is manufactured. It may be used for transporting between each process. In that case, since the abrasion powder is not attached to the disk surface on which a thin film such as a magnetic layer is to be formed, in the state where the magnetic recording disk 2 is completed, Unnecessary convex portions are not formed on the surface.

  In the above embodiment, the glass substrate is used as the nonmagnetic substrate of the magnetic recording disk 2, but a nonmagnetic substrate formed of aluminum, ceramics, silicon, carbon, titanium, or an alloy thereof is used. The present invention may be applied to the disk storage body 1 in which the magnetic recording disk 2, the magneto-optical recording disk, and their intermediate products are stored in the disk storage case 3.

  Further, in the above embodiment, the outer peripheral end portion 26 of the magnetic recording disk 2 is supported by the slope portions 382 and 383 of the insertion groove 38. However, the bottom surface portion 281 supports the magnetic recording disk 2 as a disk support portion. The present invention may be applied to the disc storage case 3. Further, in the disk storage case 3, the disk support portion is configured to support the outer peripheral end portion 26 of the disk, but the disk storage case 3 provided with a disk support portion that supports the inner peripheral end portion of the center hole of the disk. The present invention may be applied.

It is a schematic perspective view which shows the disc storage case to which this invention is applied. (A) And (b) is a front view of the disc storage case to which the present invention is applied, and is a cross-sectional view taken along the line II ′.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Disc storage body 2 Magnetic recording disk 3 Disc storage case 26 Outer peripheral edge 37 Rib 38 Insertion groove 261 Outer peripheral wall surface 262, 263 Chamfered portion 381 Bottom surface portion 382, 383 Insertion groove slope portion

Claims (10)

A magnetic recording disk in which at least an underlayer, a magnetic layer, a protective layer, and a lubricating layer are laminated on the surface of a non-magnetic substrate, or a disk that is in the process of being manufactured, and a disk that supports the disk in contact with the end of the disk In a disk storage body having a disk storage case with a support portion,
A disc container having a surface roughness Ra of the disc support portion smaller than a surface roughness Ra of an end portion of the disc.   2. The disc storage body according to claim 1, wherein an end portion of the disc that is in contact with the disc support portion is an outer peripheral end portion of the disc.   The disk storage body according to claim 1, wherein the nonmagnetic substrate is a glass substrate.   The disk storage body according to any one of claims 1 to 3, wherein the disk support portion is made of resin.   The disk storage body according to any one of claims 1 to 4, wherein the disk is the magnetic recording disk.   6. The disc storage body according to claim 1, wherein the disc support portion supports at least two portions in the circumferential direction among the end portions of the disc.   The disk storage body according to any one of claims 1 to 6, wherein a surface roughness Ra of an end of the disk is 1 µm or less.   The disk storage body according to any one of claims 1 to 6, wherein the surface roughness Ra of the end portion of the disk is 0.5 µm or less.   7. The disk storage body according to claim 1, wherein a surface roughness Ra of an outer peripheral end portion of the disk is 0.05 μm or less. A magnetic recording disk in which at least an underlayer, a magnetic layer, a protective layer, and a lubricating layer are laminated on the surface of a nonmagnetic substrate, or a disk support portion that supports the disk in contact with an end of a disk that is being manufactured. Disc storage case
A disc storage case, wherein at least a region including the disc support portion is polished.

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