JP2011204322A - Magnetic disk and method for manufacturing magnetic disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic disk and a method for manufacturing magnetic disk which can raise a yield in a manufacturing process of the magnetic disk, while improving manufacturing efficiency in the manufacturing process of an HDD device.SOLUTION: In the manufacturing process of the HDD device, quality data containing a defective address obtained by a glide check or a certify check is read from the magnetic disk manufactured in the manufacturing process of the magnetic disk and is made usable by recording, in a specific area, quality data containing at least either of the defective address of a rugged defect found by the glide check to check a rugged defect of a disk surface and the defective address of a magnetic defect found by the certify check to check the magnetic defect.

Description

  The present invention relates to a magnetic disk and a magnetic disk manufacturing method, and more particularly to a magnetic disk mounted on a hard disk drive device (HDD device) and a magnetic disk manufacturing method.

  There is a magnetic disk as a magnetic recording medium mounted on the HDD device. The magnetic disk is manufactured by using an aluminum substrate, a glass substrate or a ceramic substrate coated with a NiP film, and laminating a magnetic layer and a protective layer thereon. The manufactured magnetic disk is subjected to a glide inspection and a certification inspection as a quality evaluation inspection in a magnetic disk manufacturer, and then shipped to a magnetic disk (HDD) device manufacturer.

  The glide inspection process is a process for inspecting the irregularities on the surface of the magnetic disk. This is because the spacing between the recording / writing head (hereinafter referred to as “head”) of the HDD device and the magnetic disk (hereinafter referred to as “flying height”) is very narrow, from several tens of nanometers to several nanometers. This is to avoid a collision between the irregular defect and the head. For this reason, in the glide inspection process, the irregularity defect on the surface of the magnetic disk is inspected, and the magnetic disk having the irregularity defect is excluded from the manufacturing process as a defective product.

  In the certification inspection process, data read / write and the like are actually inspected by the head with respect to the magnetic disk that has passed the glide inspection process. The magnetic disk that has passed the certification inspection process is shipped to the HDD device manufacturer. The data written at this time is generally subjected to head erase or bulk erase (collective degaussing) and is shipped to the HDD device manufacturer. In the HDD device manufacturer, after assembling the HDD device, the contact inspection and defect inspection of the product head are performed for the same purpose as the magnetic disk manufacturer.

JP 2001-155333 A

  However, since HDD device manufacturers perform contact inspections and defect inspections of product heads for each disk, it has been difficult to improve the manufacturing efficiency of HDD devices. On the other hand, even a magnetic disk manufacturer cannot ship a magnetic disk in which a concavo-convex defect is detected in a glide inspection to an HDD apparatus manufacturer, and it has been difficult to improve the yield of the magnetic disk.

  The present invention has been made in view of such a situation, and can improve the manufacturing efficiency in the manufacturing process of the HDD device and can improve the yield in the manufacturing process of the magnetic disk and the magnetic disk. It aims at providing the manufacturing method of.

  The magnetic disk of the present invention has at least one of the defect address of the concavo-convex defect obtained by the glide inspection for inspecting the concavo-convex defect on the disk surface and the defect address of the magnetic defect obtained by the certify inspection for inspecting the magnetic defect. The quality data included is recorded in a specific area.

  The method for manufacturing a magnetic disk according to the present invention includes at least one of a step of manufacturing a magnetic disk, a glide inspection for inspecting a rugged surface defect on the surface of the manufactured magnetic disk, and a certify inspection for inspecting a magnetic defect. And writing quality data including a defect address of the defect obtained by the performed inspection at a specific position.

  According to these configurations, in the HDD device manufacturing process, the quality data including the defect address obtained by the glide inspection and the certifying inspection can be read from the magnetic disk manufactured in the magnetic disk manufacturing process and used. For example, the HDD apparatus manufacturer can omit or simplify the second defect inspection by using the defect address at the time of the certification inspection recorded by the magnetic disk manufacturer, and improve the manufacturing efficiency of the HDD apparatus. On the other hand, the magnetic disk manufacturer notifies the magnetic disk device manufacturer of the defect address by recording the defect address in a specific area at the time of the glide inspection, and avoids the collision between the concavo-convex defect and the head in the HDD device manufacturing process in advance. Can be made. For this reason, the magnetic disk manufacturer can effectively use the magnetic disk that has been disposed of as a defective product, and can improve the yield.

  According to the present invention, in the magnetic disk, the quality data recording method can be a magnetic or optical recording method.

  According to the present invention, the manufacturing efficiency can be improved in the manufacturing process of the HDD device, and the yield can be improved in the manufacturing process of the magnetic disk.

It is a figure which shows embodiment of the magnetic disc which concerns on this invention, and is a flowchart of the manufacturing process of a magnetic disc. It is a figure which shows embodiment of the magnetic disc based on this invention, and is explanatory drawing of the defect address of an uneven | corrugated defect and a magnetic defect.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, these figures, Examples, etc. and description illustrate the present invention, and do not limit the scope of the present invention. It goes without saying that other embodiments may belong to the category of the present invention as long as they match the gist of the present invention.

  As a material for the magnetic disk substrate used in the magnetic disk, aluminosilicate glass, soda lime glass, borosilicate glass, aluminum-magnesium alloy, or the like can be used. In particular, aluminosilicate glass can be preferably used in that it can be chemically strengthened and can provide a magnetic disk substrate excellent in flatness of the main surface and substrate strength. In the present embodiment, the case where the magnetic disk substrate is a glass substrate will be described.

  Hereinafter, each process of manufacturing the magnetic disk will be described with reference to FIG.

(1) Glass substrate manufacturing process For example, a glass substrate is formed by cutting out a glass disk from a glass base material such as aluminosilicate glass and applying a lapping process, a polishing process, etc. to form an outer shape, and applying chemical strengthening thereto. It is formed.

(2) Magnetic disk manufacturing process (recording layer formation process)
A perpendicular magnetic recording disk is manufactured by sequentially forming, for example, an adhesion layer, a soft magnetic layer, a nonmagnetic underlayer, a perpendicular magnetic recording layer, a protective layer, and a lubricating layer on a chemically strengthened glass substrate. Examples of the material constituting the adhesion layer include a Cr alloy. Examples of the material constituting the soft magnetic layer include a CoTaZr-based alloy. Examples of the nonmagnetic underlayer include a Ru alloy. An example of the perpendicular magnetic recording layer is a granular magnetic layer. Examples of the material constituting the protective layer include hydrogenated carbon. Examples of the material constituting the lubricating layer include fluorine-containing polymers such as perfluoropolyether. For example, these recording layers are more specifically formed on a glass substrate by using a sputtering apparatus, a CrTi adhesion layer, a CoTaZr / Ru / CoTaZr soft magnetic layer, a Ru nonmagnetic underlayer, a CoCrPt A granular magnetic layer of SiO ₂ · TiO ₂ and a hydrogenated carbon protective film are sequentially formed, and a perfluoropolyether lubricating layer is formed by a dipping method.

(3) Inspection process The magnetic disk manufactured by such a process is subjected to a glide inspection for inspecting the irregularities on the disk surface and a certification inspection for inspecting the magnetic defects on the disk surface. In the glide inspection, an inspection head is levitated on the surface of a rotating magnetic disk, the contact between the inspection head and the uneven shape on the surface of the magnetic disk is electrically detected, and the uneven defect of the magnetic disk is detected. A certify test is performed on a magnetic disk that has reached a certain quality level in the glide test.

  In the certification inspection, an inspection head is floated on the surface of a rotating magnetic disk, and writing and reading are performed in this state to detect a magnetic defect. Note that the track pitch of the certification inspection in the magnetic disk manufacturing process is, for example, 0.2 μm. The magnetic disk after the certification inspection is subjected to head erase or bulk erase (demagnetization). Quality data including the defect address of the concavo-convex defect detected by the glide inspection and the defect address of the magnetic defect detected by the certify inspection is written in a specific area of the magnetic disk.

  In this case, as shown in FIG. 2, in the glide inspection and the certification inspection, the position information of the concavo-convex defect and the magnetic defect is obtained from the distance R from the rotation center of the disk and the rotation angle θ from the reference angle.

  The specific area in which the quality data of the magnetic disk is written is an area defined in advance between the magnetic disk manufacturer and the HDD device manufacturer. Thus, by predefining a specific area between manufacturers, the HDD device manufacturer can read and use quality data from the specific area in the manufacturing process of the HDD device. The specific area is provided, for example, on the outer periphery of the magnetic disk.

  The quality data of the magnetic disk is not limited to the configuration written in a single specific area, and may be configured to be written in a plurality of specific areas. Thereby, in the manufacturing process of the HDD device, when one specific area cannot be read due to the unevenness defect and the magnetic defect, the quality data can be read from the other specific area.

  The magnetic disk that has undergone the inspection process is shipped from the magnetic disk manufacturer to the HDD device manufacturer. The magnetic disk shipped to the HDD device manufacturer is incorporated into the HDD device and subjected to an inspection process in the HDD device manufacturing process. In this inspection process, head contact inspection and defect inspection are performed for the same purpose as the magnetic disk manufacturer. At this time, the certification inspection can be omitted or simplified by reading the quality data from the specific area of the magnetic disk.

  That is, in the manufacturing process of the HDD device manufacturer, since the defect address of the magnetic disk is already recorded in the specific area as quality data in the manufacturing process of the magnetic disk, it is not necessary to re-inspect the defect inspection. Further, even when the defect inspection is re-inspected, it is not necessary to re-inspect at least the defective portion, so that the inspection time can be shortened. The track pitch for defect inspection in the HDD device manufacturing process is, for example, 0.2 μm. As described above, since the defect inspection can be omitted or simplified in the manufacturing process of the HDD device, the manufacturing efficiency of the HDD device can be improved.

  Further, in the magnetic disk manufacturing process of the magnetic disk manufacturer, the defect address of the uneven defect is notified to the HDD device manufacturer by writing the defect address of the uneven defect as quality data in a specific area. That is, in the manufacturing process of the HDD device manufacturer, collision between the concave and convex defect and the head is avoided in advance, so that the magnetic disk that has been disposed of as a defective product by the magnetic disk manufacturer can be used effectively.

  In addition, since the concave / convex defect and the magnetic defect position information recorded on the magnetic disk are converted into the CHS method by the HDD device manufacturer, the defect address can be easily specified in the HDD device manufacturing process. It has become. In the above-described embodiment, the position information of the concavo-convex defect and the magnetic defect is converted to the CHS method. However, the present invention is not limited to this configuration. In the manufacturing process of the HDD device, the defect address may be recorded by any method as long as the position information of the concavo-convex defect and the magnetic defect can be specified.

  As described above, according to the magnetic disk according to the present embodiment, in the HDD device manufacturing process, the quality including the defect address obtained from the magnetic disk manufactured in the magnetic disk manufacturing process by the glide inspection or the certification inspection. Data can be read and used. For example, the HDD device manufacturer can use the defect address at the time of the certification inspection recorded by the magnetic disk manufacturer to omit or simplify the second defect inspection and improve the manufacturing efficiency of the HDD device. Become. On the other hand, the magnetic disk manufacturer notifies the HDD device manufacturer of the defect address by recording the defect address in the specific area at the time of the glide inspection, and avoids the collision between the concavo-convex defect and the head in the HDD device manufacturing process in advance. be able to. For this reason, the magnetic disk manufacturer can effectively use the magnetic disk that has been disposed of as a defective product, and can improve the yield.

  In the above-described embodiment, the configuration in which the magnetic disk is mounted on the HDD device has been described. However, the present invention is not limited to this configuration. The magnetic disk only needs to be mounted on the magnetic disk device. For example, the magnetic disk may be configured to be used in a removable disk device.

  In the above-described embodiment, the quality data including the defect addresses of the concavo-convex defect and the magnetic defect may be recorded so as to be readable in a specific area of the magnetic disk. Alternatively, an optically readable configuration may be used.

  In the above-described embodiment, the quality data includes the defect address of the concavo-convex defect and the magnetic defect. However, the quality data may include any one of them. The quality data may include defect addresses of other defects and additional information used in other HDD device manufacturing processes. For example, it is possible to include the magnetostatic characteristics (Hc, Hn, etc.) of the magnetic disk in the quality data, and to select an optimum track pitch in combination with the magnetic head in the HDD device manufacturing process.

  The embodiment disclosed this time is illustrative in all respects and is not limited to this embodiment. The scope of the present invention is shown not by the above description of the embodiments but by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

  As described above, the present invention has an effect that the manufacturing efficiency can be improved in the manufacturing process of the magnetic disk (HDD) device and the yield can be improved in the manufacturing process of the magnetic disk.

Claims (3)

  Quality data including at least one of the defect address of the uneven defect obtained by the glide inspection for inspecting the uneven defect on the disk surface and the defect address of the magnetic defect obtained by the certification inspection for inspecting the magnetic defect is in a specific area. A magnetic disk characterized by being recorded on.   2. The magnetic disk according to claim 1, wherein the quality data recording method is magnetic or optical. Manufacturing a magnetic disk;
The manufactured magnetic disk is subjected to at least one of a glide inspection for inspecting the concave / convex defect on the disk surface and a certification inspection for inspecting a magnetic defect, and includes a defect address of the defect obtained by the inspection performed. And writing the quality data at a specific position.

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