JP3137772B2 - Magnetic disk drive and evaluation method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk drive having a large storage capacity and a method for evaluating the same, and more particularly, to the generation of gas in the magnetic disk drive, which is an index of performance deterioration of the magnetic disk drive. The present invention relates to a magnetic disk device to be checked and an evaluation method thereof.

[0002]

2. Description of the Related Art Generally, in order to increase the capacity of a magnetic disk drive, it is indispensable to reduce the spacing between the magnetic head and the magnetic disk and to reduce the space. However, accompanying this, the frequency of contact between the head and the disk and the frequency of friction increase, and it becomes susceptible to a small amount of mixed gas, which is a serious problem in maintaining the reliability of the magnetic disk device. In order to maintain reliability, research on the sliding of the head / disk has been repeated, and various improvements have been made to both the head and the disk. For example,
“Tribology and Mechanics
of Magnetic Storage Device
es "(edited by B. Bushan, Springer-V
erlag, New York, 1990) p.
As shown on page 337 or the like, a method of measuring a wear speed or a frictional force by rotating a disk at a low speed so that the head does not float, or a method of detecting a contact vibration detecting element such as an AE sensor or a piezo element on the head. It has been practiced to analyze sliding phenomena by a method of mounting and examining a floating state, and to provide feedback to a design. In addition, non-contact, non-destructive analysis methods, such as infrared absorption spectroscopy, ellipsometry,
Analysis of gas generated during sliding is also used at the experimental level as an effective means for analyzing phenomena. In particular, gas analysis by a mass spectrometer is effective.
On page 94, the results of a disk sliding test performed in a vacuum chamber and the generated gas analyzed by a mass spectrometer are reported.

[0003]

In the prior art described above, in many cases, a special head or special operating conditions are required for the analysis of the sliding phenomenon, and the phenomenon occurring in the magnetic disk drive in the experiment is directly used. It cannot be analyzed directly. For example, mass spectrometry of gas generated at the time of sliding is an effective means, but for analysis, the inside of the apparatus must be evacuated. The floating head cannot be used in a vacuum, and the gas generation mechanism is completely different between a vacuum and the atmosphere. Therefore, the analysis result cannot be directly applied to an actual apparatus. For this reason, conventionally, there has been no idea of predicting the degree of deterioration of the magnetic disk device based on the state of gas generation and the like in the state of use of the magnetic disk device, and the analysis of the sliding phenomenon in the actual magnetic disk device has It could only be done in the form of a post-mortem analysis after a slide that caused significant damage occurred.

In order to improve such a situation, a mechanism for capturing a sliding phenomenon or a precursory phenomenon (precursor phenomenon) is required in an actual magnetic disk drive or an experimental apparatus under the same conditions as the actual magnetic disk drive. It is indispensable to apply a technique capable of measuring at high sensitivity under atmospheric pressure.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems of the prior art, and to provide an actual magnetic disk drive or an experimental apparatus under similar conditions to a magnetic disk serving as an index of a sliding phenomenon or a precursory phenomenon thereof. It is an object of the present invention to provide a magnetic disk device capable of detecting and measuring a gas generation state in the device at an early stage, and an evaluation method thereof.

[0006]

In order to achieve the above object, a method for evaluating a magnetic disk drive according to the present invention uses a mass spectrometer that ionizes a sample under atmospheric pressure and uses a mass spectrometer inside the magnetic disk drive. It detects the generated gas or gas that has entered from the outside.

The gas detected by the mass spectrometer is
Gas generated from a component of a magnetic disk or a magnetic head (a gas caused by a component) or a gas that causes damage to a magnetic disk or a magnetic head (a cause of head-to-disk failure or sliding phenomenon) Known gas), and when this gas is detected,
It is determined that an abnormality has occurred.

Further, when this abnormality occurs, an alarm may be generated, the magnetic disk device is stopped, the magnetic head is evacuated, or the recorded contents on the magnetic disk are backed up.

Further, one mass spectrometer can be connected to a plurality of magnetic disk devices to evaluate the entire magnetic disk system at the same time, or to evaluate each device in a time-division manner. Further, if the mass spectrometer is provided with a mechanism for collecting gas from the magnetic disk device, it can be used as a general-purpose evaluation means for appropriately evaluating the internal environment of an arbitrary magnetic disk device.

[0010]

The operation based on the above configuration will be described.

Generally, in a magnetic disk drive, various phenomena occur due to a sliding phenomenon such as contact and friction between a magnetic head and a magnetic disk. Above all, the generation of gas accompanying the decomposition of the lubricating film and the protective film of the disk is important information that reflects the state of sliding. For example, carbon as a protective film material for magnetic disks and fluororesin as a lubricant for magnetic disks react or decompose with oxygen in the air due to frictional heat generated by the sliding phenomenon, resulting in gases containing carbon gas and fluorine. Occurs. Also, gas may be generated from the protective film of the magnetic head and the lubricant. The way these gases are generated is completely different in a vacuum and in the atmosphere, so to accurately understand the phenomena occurring in actual magnetic disk drives, apply a method that can be analyzed under atmospheric pressure. is necessary.

A mass spectrometer that ionizes a sample under atmospheric pressure is an excellent analytical technique that can analyze gas in a magnetic disk device, which is usually at atmospheric pressure, as it is and with high sensitivity. According to the present invention, by adopting this method, it is possible to catch the head / disk sliding phenomenon at a slight stage (precursor stage) in the actual operating state of the magnetic disk device, and to issue an alarm. By taking measures such as stopping the apparatus and backing up the recorded contents, it is easy to prevent the worst situation such as loss of recorded data beforehand. Further, it is known that a certain kind of gas enters the magnetic disk device from the outside and causes a sliding phenomenon. For example, if sulfurous acid gas in a hot spring area or chlorine-based gas in a coastal area invades from the outside, the magnetic disk is deteriorated and causes a failure.
Further, when the siloxane gas enters, it adheres and bonds to the surfaces of the magnetic disk and the magnetic head, causing sliding. This mass spectrometer is also effective for detecting these invading gases.

[0013]

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

(Embodiment 1) In this embodiment, a mass spectrometer for ionizing a sample under atmospheric pressure is mounted on a magnetic disk drive. FIG. 1 shows a schematic diagram of this embodiment. In FIG. 1, 1 is a magnetic disk device, 2 is a mass spectrometer of the atmospheric pressure ionization type, 3 is a sampling tube, 4 is an output monitor of analysis results, 5 is an alarm, and 6 is a gas cylinder.

A small amount of gas generated inside the magnetic disk drive 1 is taken into the mass spectrometer 2 through the sampling tube 3, and the type and amount of generated gas are analyzed. The analysis result is output to the monitor 4 or the like in real time, and an alarm is transmitted from the alarm 5 as necessary. A gas cylinder 6 may be connected to control the internal environment (in order to prepare the experimental environment by filling the disk device with high-purity, uncontaminated air or nitrogen before the experiment). This apparatus makes it easy to detect the occurrence of head / disk sliding at a very small precursor stage and to take measures to prevent accidents such as loss of recorded data. Further, a mechanism for automatically taking an accident prevention measure may be added.

FIG. 2 shows an example in which a fluorine-based organic substance corresponding to a decomposition product of a lubricating film on the disk surface is analyzed by this apparatus. The detection sensitivity of the target substance was on the order of ppb. For example, when detection of about 1 to 10 ppb or more is detected, it is considered that an abnormality has occurred, and an accident prevention measure can be taken.

(Embodiment 2) In this embodiment, a mass spectrometer for ionizing a sample under atmospheric pressure is incorporated in a magnetic disk drive. FIG. 3 shows a schematic configuration of the apparatus of the present embodiment. 3, parts having the same names as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. 7 is a signal cable, 8
Is a disk controller, and 9 is an air intake hole.
The trace gas generated from the magnetic disk drive 1 is taken into the mass spectrometer 2. The analysis result is output to an output device such as the monitor 4. When an abnormality is detected, an alarm is issued from the alarm device 5, and at the same time, a control signal is sent to the controller 8 through the signal cable 7 to stop the magnetic disk device and to stop data transmission. Perform backup, head retraction, etc. The magnetic disk device 1 is provided with an air intake 9 provided with a filter for supplementing the air extracted from the sampling tube 3. The condition for determining the presence or absence of an abnormality can be set arbitrarily. For example, it is preferable that an abnormality is determined when a predetermined concentration of a fluorine-based organic substance, which is a decomposition product of a lubricating film on a disk, is detected.

(Embodiment 3) In this embodiment, a mass spectrometer of the atmospheric pressure ionization type is attached to a magnetic disk system composed of a plurality of magnetic disk devices. FIG. 4 shows a schematic configuration of the present embodiment. 4, the same reference numerals are given to the parts having the same names as those in FIGS. 1 and 3, and the description is omitted. In this embodiment, the mass spectrometer 2 is provided in common for each magnetic disk device 1.

As shown in FIG. 4, the gas collected from all the magnetic disk devices 1 may be analyzed at the same time. However, the sample gas from each magnetic disk device can be analyzed in time by separately providing a collecting tube 3 and combining with a valve. A configuration in which measurement is performed separately may be employed. Further, a plurality of mass spectrometers may be provided. When the mass spectrometer of the atmospheric pressure ionization method is used, the pressure does not always have to be strictly the atmospheric pressure (1 atm). For example, the detection measurement can be performed up to about 1/2 atm.

It is to be noted that a mass spectrometer provided with a sample collection tube is installed so that an arbitrary magnetic disk device can be appropriately evaluated, and can be used for general purposes.

As for the magnetic disk device, it is particularly effective for a closed type device when detecting gas generated inside, but even for a non-closed type device, the air flow flowing between the head and the disk can be checked. , It is possible to analyze the gas generation status.

[0022]

As described above in detail, according to the present invention, in a magnetic disk drive and a method of evaluating the quality of the magnetic disk drive by analyzing the gas generated inside the magnetic disk drive, the analysis can be performed. Since a mass spectrometer that ionizes a sample under atmospheric pressure or a pressure close to this is used, the magnetic flux generated in the magnetic disk drive that is actually operating without affecting the magnetic disk drive Minor abnormal phenomena such as gas generation due to disk / magnetic head sliding can be detected, and the effect of easily preventing data loss and other accidents from occurring can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a method for evaluating a magnetic disk drive using an atmospheric pressure ionization mass spectrometer according to an embodiment of the present invention.

FIG. 2 is a diagram showing an example in which a fluorine-based organic substance is analyzed by an atmospheric pressure ionization type mass spectrometer according to an embodiment of the present invention.

FIG. 3 is a diagram showing an example in which an atmospheric pressure ionization type mass spectrometer is incorporated in the magnetic disk drive of the embodiment of the present invention.

FIG. 4 is a diagram showing an example in which a mass spectrometer is attached to a plurality of magnetic disk devices according to an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic disk apparatus 2 Atmospheric pressure ionization type mass spectrometer 3 Sampling tube 4 Output monitor of analysis result 5 Alarm 6 Gas cylinder 7 Signal cable 8 Disk controller 9 Air intake hole

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Norio Nakagawa 2880 Kozu, Odawara-shi, Kanagawa Hitachi, Ltd. Storage Systems Division (72) Inventor Yasuhiro Mitsui Yasuhiro Mitsui 1-280, Higashi-Koikekubo, Kokubunji-shi, Tokyo Hitachi, Ltd. Inside the research institute (72) Inventor Toshiaki Mizogami 3-3-2 Fujibashi, Ome-shi, Tokyo Hitachi Tokyo Electronics Co., Ltd. (56) References Proceedings of the Japan Society of Lubrication Society Tribology Conference (1992-5), pp. 491-494 Proceedings of the 34th Annual Meeting of the Japanese Society of Lubrication, Proceedings (1989), pp. 429-432, Anal. Chem. Vol. 59 (1987), no. 24, p. 2924-2927 (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 27/62-27/70 H01J 49/00-49/48 G11B 5/00 G11B 33/14 501 JICST file (JOIS)

Claims (3)

(57) [Claims] An evaluation of a magnetic disk drive characterized by detecting a gas generated inside a magnetic disk drive or a gas entering from the outside using a mass spectrometer that ionizes a sample under atmospheric pressure. Method. 2. The gas detected by the mass spectrometer is a gas generated from a component of a magnetic disk or a magnetic head, or a gas causing damage to a magnetic disk or a magnetic head. The method for evaluating a magnetic disk drive according to claim 1. 3. When a gas generated inside the magnetic disk device or a gas entering from the outside is detected by a mass spectrometer that ionizes a sample under atmospheric pressure, an alarm is generated and the magnetic disk device is stopped. A magnetic head device for retracting the magnetic head or backing up recorded contents on the magnetic disk.