JP2002056643A - Magnetic disk device and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable magnetic disk device which is capable of suppressing the occurrence of the chemical reaction of constituting members, the rotation failure of a magnetic disk, head crash, etc., by lessening the infiltration of harmful gases, dust etc., into an exterior case. SOLUTION: A filter 7a built into the exterior case 4 is a gas selective filter which allows the selective permeation of the specific gas and is more particularly a membrane to allow the selective permeation of nitrogen.

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 in which a filter for equalizing the pressure inside an outer case and the atmospheric pressure is incorporated.

[0002]

2. Description of the Related Art Conventionally, an outer case of a magnetic disk drive has a breathable upper surface of the outer case to prevent the outer case from being deformed by a pressure difference caused by a temperature difference between the inside of the outer case and the outside air. Filter is installed.

[0003] This breathing filter usually incorporates a filter made of non-woven fabric or the like, and is configured to eliminate the pressure difference by circulating the air and the outside air in the outer case. Not only does it function as a respiratory filter, but it also has the purpose of preventing dust from entering from outside and eliminating dust inside.Furthermore, the filter is combined with activated carbon to absorb harmful gas molecules. In some cases, the inside of the outer case is cleaned.

[0004]

However, in the above-mentioned conventional respiratory filter, sulfur oxides (SOx) and nitrogen oxides (NOx) generated by air pollution due to exhaust gas and industrial exhaust accompanying the recent increase in automobiles and the like. Harmful substances such as SOx and NOx inside the outer case.
Penetrates and causes a chemical reaction with the components, and the products (eg, sulfides, nitrides or peroxides) on the surface
Problem.

In recent years, as a magnetic disk as a recording medium, a thin film magnetic disk using a cobalt-based alloy as a magnetic film has been started to be used for improving a recording density. Such a thin film magnetic disk is used. in case of,
The following problems are caused by the above SOx and NOx.

A thin film magnetic disk is generally provided with a protective film for preventing damage or corrosion of a magnetic film. In particular, a magnetic disk having a magnetic disk having a protective film containing carbon as a main component is mounted. In the apparatus, when the contact start / stop is repeatedly performed, the frictional force between the magnetic head and the magnetic disk increases, so that the magnetic disk becomes unrotatable or a head crash occurs. This head crash is due to the smoothing of the surface due to the abrasion of the carbon protective film, and the mechanism of this abrasion is not merely mechanical abrasion, but vaporization (oxidative abrasion) due to oxidation of carbon in the atmosphere. It is said that.

The present invention solves the above-mentioned problems and reduces the invasion of harmful gases and dusts into the interior of the outer case, thereby suppressing the occurrence of chemical reactions of the constituent members, the inability to rotate the magnetic disk, and the head crash. It is an object of the present invention to provide a highly reliable magnetic disk device.

[0008]

The magnetic disk drive of the present invention is characterized in that a gas selective permeable filter is incorporated in an outer case.

According to the present invention, a more stable and highly reliable magnetic disk drive is realized by reducing the intrusion of harmful gases, dusts, oxygen and the like into the outer case which may interfere with the operation of the magnetic disk drive. it can.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A magnetic disk drive according to a first aspect of the present invention is a magnetic disk drive in which a filter for equalizing the internal pressure of an outer case and the external atmospheric pressure is incorporated. It is a gas selection filter for selecting and transmitting a specific gas.

According to this configuration, the harmful gas is prevented from entering the inside of the outer case, and the components inside the outer case are selectively transmitted to the outside, so that adverse effects on the magnetic disk drive are suppressed, and Stabilization can be achieved.

According to a second aspect of the present invention, there is provided a method of manufacturing a magnetic disk drive, comprising: assembling the magnetic disk drive according to the first aspect of the present invention under reduced pressure; To make the pressure inside the outer case equal to the atmospheric pressure.

According to a third aspect of the present invention, there is provided a magnetic disk drive, comprising: a motor for driving the magnetic disk; and a magnetic head for accessing the magnetic disk and recording / reproducing information therein. In a magnetic disk drive in which a filter for equalizing the internal atmospheric pressure and the atmospheric pressure is incorporated, the filter is a film that selectively transmits nitrogen into the outer case.

According to this configuration, by selectively permeating nitrogen into the outer case, the intrusion of harmful gas into the outer case can be reduced, adverse effects on the magnetic disk device can be suppressed, and the device can be stabilized. .

According to a fourth aspect of the present invention, in the magnetic disk drive according to the third aspect, the filter is a nitrogen-enriched film. In the magnetic disk drive according to a fifth aspect of the present invention, when assembling the magnetic disk drive according to the third aspect, the atmosphere in the outer case is assembled at a pressure lower than the atmospheric pressure, and then returned to the atmospheric pressure and the gas selection filter is returned. And the internal pressure of the outer case is made equal to the atmospheric pressure.

According to this configuration, when the pressure inside the outer case is reduced to the atmospheric pressure by assembling the inside of the outer case, nitrogen preferentially enters the inside of the outer case when the atmospheric pressure is returned to the atmospheric pressure. Can be suppressed from entering.

According to a sixth aspect of the present invention, there is provided a magnetic disk drive, comprising: a motor for driving the magnetic disk; and a magnetic head for accessing the magnetic disk and recording / reproducing information therein. In a magnetic disk drive in which a filter for equalizing the internal atmospheric pressure and the atmospheric pressure is incorporated, the filter is a film capable of selecting a gas type to be transmitted through control by an electromagnetic field.

According to a seventh aspect of the present invention, in the magnetic disk drive according to the sixth aspect, the filter is a polymer / liquid crystal composite film. The magnetic disk drive according to claim 8 of the present invention is characterized in that, in claim 6, the filter is a film that does not allow oxygen molecules to pass through.

According to a ninth aspect of the present invention, there is provided a magnetic disk drive, comprising: a motor for driving the magnetic disk; and a magnetic head for accessing the magnetic disk and recording / reproducing information therein. In a magnetic disk drive in which a filter for equalizing the internal atmospheric pressure and the atmospheric pressure is incorporated, the filter includes a film for selectively transmitting nitrogen into the exterior case and a film for selectively transmitting nitrogen to the exterior case. And characterized by the following.

According to this configuration, nitrogen preferentially permeates into the outer case and permeates preferentially to the outside of the outer case, so that oxygen and other harmful gases from the outside enter the outer case. Intrusion can be reduced, and the pressure inside the outer case can be made equal to the atmospheric pressure, so that the device can be stabilized.

According to a tenth aspect of the present invention, in the ninth aspect, the film for selectively transmitting nitrogen into the outer case and the film for selectively transmitting nitrogen out of the outer case are both provided. It is a nitrogen-enriched film.

In the magnetic disk drive according to the present invention, the film for selectively transmitting nitrogen into the outer case and the film for selectively transmitting nitrogen to the outer case may be combined. It is a polymer / liquid crystal composite film.

According to a twelfth aspect of the present invention, there is provided a magnetic disk drive according to the ninth aspect, wherein the film for selectively transmitting nitrogen into the outer case and the film for selectively transmitting nitrogen to the outside of the outer case. One of them is a nitrogen-enriched film, and the other is a polymer / liquid crystal composite film.

According to a thirteenth aspect of the present invention, there is provided a magnetic disk drive, comprising: a motor for driving the magnetic disk; and a magnetic head for accessing the magnetic disk and recording / reproducing information therein. In a magnetic disk drive in which a filter for equalizing the internal atmospheric pressure and the atmospheric pressure is incorporated, the filter includes a film for selectively transmitting nitrogen into the outer case and a film for selectively transmitting oxygen to the outside of the outer case. It is characterized by consisting of.

According to a fourteenth aspect of the present invention, in the magnetic disk drive according to the thirteenth aspect, the film for selectively transmitting nitrogen into the outer case is a nitrogen-enriched film, and oxygen is selectively removed from the outer case. Wherein the membrane that is permeable to oxygen is an oxygen-enriched membrane.

According to a fifteenth aspect of the present invention, in the magnetic disk drive according to the thirteenth aspect, the film for selectively permeating nitrogen into the outer case is a polymer / liquid crystal composite film, and selectively selectively covers oxygen. The membrane to be permeated out of the case is an oxygen-enriched membrane.

According to a sixteenth aspect of the present invention, in the magnetic disk drive according to the thirteenth aspect, the film for selectively transmitting nitrogen into the outer case is a nitrogen-enriched film, and oxygen is selectively removed from the outer case. The film that transmits light through the substrate is a polymer / liquid crystal composite film.

According to a seventeenth aspect of the present invention, in the magnetic disk drive according to the thirteenth aspect, both the film for selectively transmitting nitrogen into the outer case and the film for selectively transmitting oxygen to the outside of the outer case are provided. It is a polymer / liquid crystal composite film.

Hereinafter, embodiments of the present invention will be described with reference to FIGS.
This will be described with reference to FIG. (Embodiment 1) FIGS. 1 to 3 show (Embodiment 1) of the present invention.

This (Embodiment 1) differs from the above-mentioned conventional example in that a gas selection filter is used as a breathing filter. As shown in FIG. 1, the magnetic disk device includes a motor 2 for driving the magnetic disk 1 and a magnetic head 12 for accessing and recording / reproducing information by accessing the magnetic disk 1 inside an outer case 4. On the upper surface of the outer case 4, a filter 7a for equalizing the atmospheric pressure inside the outer case 4 with the atmospheric pressure is incorporated. Reference numeral 3 denotes a tension arm unit that supports the magnetic head 12.

The outer case 4 includes a lower cover 5a to which the motor unit 2, the tension arm unit 3 and other main components are attached, and an upper cover 5b covering the upper surface of the lower cover 5a. The packing material 8 is interposed between the cover 5b and the upper cover 5b is fastened to the lower cover 5a with screws 9 to shield the outer case 4.

As shown in FIG. 2, the upper cover 5b has
A hole 6a through which gas flows between the outside and the inside of the outer case 4 is formed, and a filter 7a is attached to the upper cover 5b with an adhesive or the like so as to cover the upper surface thereof.

The outer case 4 thus shielded
Can prevent intrusion of dust and the like from the outside, and allow gas to flow between the outside and the inside of the outer case 4 via the filter 7a covering the hole 6a.

The filter 7a is a gas selection filter having a configuration specific to this (Embodiment 1), and selects a specific gas so that oxygen, harmful gas, dust, and the like are not taken into the exterior case 4. It is configured to be transparent.

More specifically, as shown in FIG. 3, when a gas in which gas molecules 10 to be permeated and gas molecules 11 not to be permeated mixed together reaches the filter 7a inside the outer case 4, a non- On the surface of the filter 7a made of a porous film, a small amount of gas is dissolved and reaches equilibrium at the interface. The dissolved gas diffuses into the filter 7a, reaches the opposite side of the filter 7a, and is desorbed. By this dissolution and diffusion, the gas molecules 10 to be permeated can be selectively transmitted to the opposite side of the membrane, and the other gas molecules 11 can be selectively prevented from permeating, so that the so-called gas can be separated. Become.

Therefore, by using the filter 7a having gas selection characteristics corresponding to the molecules 11 not to be permeated such as harmful gas and the gas molecules 10 to be permeated such as nitrogen, for example, Internal deterioration can be reduced.

In the magnetic disk drive constructed as described above, when the magnetic disk drive is assembled at a reduced pressure lower than the atmospheric pressure at the time of manufacture and then returned to the atmospheric pressure, the outer case 4 is positively activated via the filter 7a. Since the gas molecules 10 to be permeated are permeated into the inside, gas permeation can be performed more efficiently.

For example, when the gas molecules 10 to be permeated are nitrogen, if a nitrogen-enriched film is used as the filter 7a, when the assembly is performed at a pressure lower than the atmospheric pressure and the pressure is returned from the reduced pressure to the atmospheric pressure, the nitrogen is reduced. Nitrogen more selectively permeates into the outer case 4 from the enriched film, and a magnetic disk device with a lower oxygen concentration inside the outer case 4 can be obtained.

As described above, by selecting a specific gas and positively taking it into the outer case 4, it is possible not only to reduce intrusion of dust into the outer case 4 but also to reduce oxygen, SOx, Oxidation and breakage of the components can be reduced by reducing the intrusion of NOx, phenomena such as head crash can be suppressed, and a highly reliable magnetic disk device can be realized.

In the above description, the case where a specific gas is taken into the exterior case 4 through the filter 7a has been described as an example. However, the exterior case 4 is used as the filter 7a.
By using a filter having a characteristic of discharging a specific gas from the inside through the filter 7a, deterioration inside the outer case 4 can be reduced as compared with the related art. For example, filter 7a
When an oxygen-enriched film is used, oxygen inside the outer case 4 permeates to the outside and oxidation of components inside the outer case 4 can be suppressed.

(Embodiment 2) This (Embodiment 2) is different in that a polymer / liquid crystal composite film is used as the filter 7a as a gas selection filter. This is the same as the embodiment 1).

As the polymer / liquid crystal composite film used as the filter 7a, a liquid crystal in which low-molecular liquid crystal is dispersed as a three-dimensional continuous layer is usually used, and the orientation of the liquid crystal molecules is changed by control by an electromagnetic field. By doing so, the gas to be permeated can be selected, and so-called gas can be separated.

When such a filter 7a is used, it is possible to control such that harmful substances do not enter the inside of the outer case 4, and a specific gas is selectively transmitted from the outside of the outer case 4 to enter the inside of the outer case 4. Can be configured to enter.

For example, when the electromagnetic field is controlled so that the polymer / liquid crystal composite film selectively transmits nitrogen, nitrogen can be positively taken into the outer case 4 in the same manner as in the first embodiment. If the magnetic disk device is assembled under reduced pressure at the time of assembling, a magnetic disk device having a low oxygen concentration inside the outer case 4 can be obtained.

(Embodiment 3) FIGS. 4 and 5 show (Embodiment 3) of the present invention. In this (Embodiment 3),
The difference is that a plurality of gas selection filters are provided, but the other basic configuration is the same as in each of the above embodiments.

As shown in FIG. 4, holes 6b and 6c are formed in the outer case 4 in which the magnetic disk 1 is incorporated, and the upper surface thereof is covered with filters 7b and 7c as shown in FIG. The gas flows between the outside and the inside of the case 4.

The filters 7b and 7c are the same gas selection filters as in the above embodiments. When the plurality of filters 7b and 7c are provided in the outer case 4 as described above, not only the pressure inside and outside the outer case 4 becomes equal, but also nitrogen selectively permeates into the outer case 4 and the outer case 4 Since nitrogen selectively permeates outside the outer case 4, the oxygen concentration inside the outer case 4 is reduced, and a highly reliable magnetic disk device can be obtained.

For example, when the filters 7b and 7c are both nitrogen-enriched films, as shown in FIGS. 6 (a) and 6 (b), nitrogen is selectively supplied from the exterior of the exterior case 4 to the interior of the exterior case 4. And nitrogen is selectively transmitted from the inside to the outside of the outer case 4. FIG. 6A shows a pattern (A) in which nitrogen is taken into the exterior case 4 by the filter 7b and nitrogen is exhausted from the inside to the outside by the filter 7c, and FIG. Case 4
(B) is a pattern in which nitrogen is discharged to the outside from the inside and nitrogen is taken into the exterior case 4 by the filter 7c.

The nitrogen-enriched film is a film that allows nitrogen to pass through one way, and both the pattern (A) and the pattern (B) can be made by changing the mounting of the film up and down. Therefore, it is only necessary that the membranes of the filters 7b and 7c are mounted upside down, and the pattern of (A) or the pattern of (B) is not limited.

When the magnetic disk drive rotates, heat is generated inside the outer case 4 by driving the motor and the internal pressure becomes higher than the outside, so that the nitrogen-enriched film “takes nitrogen” into the outer case 4. The internal pressure increases only if the orientation is provided only in the direction, and the disk device may be deformed. However, as described above, the direction in which one of the nitrogen-enriched films "takes" nitrogen into the exterior case 4 is used. If the other nitrogen-enriched film is oriented so as to “exhaust” nitrogen to the outside, the pressure difference between the inside and outside of the outer case 4 can be eliminated to prevent deformation of the disk device. In addition, since the flow of air inside the outer case 4 is improved, the internal heat can be actively released to the outside, and even if the flow of air is improved, the flow of excess oxygen in and out due to the effect of the nitrogen-enriched film. Therefore, the oxygen concentration inside the outer case 4 can be reduced.

The gas selection filters 7b and 7c
Are not only nitrogen-enriched films, but also both may be polymer / liquid crystal composite films, or one may be a nitrogen-enriched film and the other may be a polymer / liquid crystal composite film. . As described above, the filter 7a, 7b is not particularly limited as long as it is a film selectively permeating a specific gas, particularly nitrogen, and the two gas selection filters 7b, 7c are used in the above description. Although provided, the number is not particularly limited.

(Embodiment 4) This (Embodiment 4) differs from the above (Embodiment 3) in that the filters 7b and 7c select different types of gases, respectively.

For example, if the filter 7b is a membrane for selectively transmitting nitrogen into the container and the filter 7c is configured to transmit oxygen to the outside of the container, a nitrogen-enriched film is used as the filter 7b and an oxygen-enriched film is used as the filter 7c. An enriched membrane can be suitably used.

In the magnetic disk drive provided with these filters 7b and 7c, when nitrogen reaches the surface of the nitrogen-enriched film from the outside of the outer case 4, nitrogen selectively permeates into the outer case 4 according to the principle. Then, oxygen inside the outer case 4 is transmitted to the outside of the outer case 4 by the oxygen-enriched film.

With this configuration, not only the pressure inside and outside the outer case 4 becomes equal, but also the oxygen concentration inside the outer case 4 is low, and a highly reliable magnetic disk device can be realized.

The oxygen-enriched film has the property of permeating and diffusing oxygen only in the surface layer, and the opposite side is formed of a sheet (for example, a nonwoven fabric or a porous sheet) supporting the surface layer. ing. Therefore, when viewed as a whole, the oxygen-enriched film permeates oxygen one way from the surface of the film to the opposite side, but does not permeate in the opposite direction, so that the oxygen inside is transmitted to the outside. If a film is provided in the direction, external oxygen does not permeate inside.

In the above description, the nitrogen-enriched film is taken as an example of the filter 7b, and the oxygen-enriched film is taken as an example of the filter 7c. However, the present invention is not limited to this. 7b is a polymer / liquid crystal composite film,
The filter 7c is an oxygen-enriched film, the filter 7b is a nitrogen-enriched film, the filter 7c is a polymer / liquid crystal composite film, and the filters 7b and 7c are both a polymer / liquid crystal composite film. Is mentioned. In the above description, two gas selection filters 7b and 7c are provided.
The number is not particularly limited.

[0058]

As described above, according to the magnetic disk drive of the present invention, there is provided a magnetic disk drive in which a filter for equalizing the internal pressure of the outer case and the external atmospheric pressure is incorporated. A gas selection filter that selectively permeates specific gases to reduce the intrusion of harmful gases and dust into the interior of the outer case. A highly reliable magnetic disk drive capable of suppressing a crash or the like can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view of a magnetic disk drive according to a first embodiment of the present invention.

FIG. 2 is a longitudinal sectional view of an installation portion of a filter 7a in FIG.

FIG. 3 is a diagram showing the principle of gas separation of a filter.

FIG. 4 is a perspective view of a magnetic disk drive according to a third embodiment of the present invention.

FIG. 5 is a longitudinal sectional view of an installation portion of the filters 7b and 7c in FIG.

FIG. 6 is a schematic diagram illustrating a specific example of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Magnetic disk 2 Motor unit 3 Tension arm unit 4 Outer case 7a, 7b, 7c Filter 10 Gas molecules to be transmitted 11 Other gas molecules

Claims (17)

[Claims] 1. A magnetic disk drive in which a filter for equalizing an internal pressure of an outer case and an external atmospheric pressure is incorporated, wherein the filter is a gas selection filter for selecting and transmitting a specific gas. Disk device. 2. When assembling the magnetic disk drive according to claim 1, after assembling under reduced pressure, the pressure is returned to the atmospheric pressure, a specific gas is passed through a gas selection filter, and the pressure inside the outer case is reduced to the atmospheric pressure. A method of manufacturing a magnetic disk drive for equalizing. 3. A filter for equalizing the atmospheric pressure and the atmospheric pressure inside the outer case is provided in an outer case incorporating a motor for driving the magnetic disk and a magnetic head for accessing the magnetic disk and recording / reproducing information by accessing the magnetic disk. The magnetic disk device according to claim 1, wherein the filter is a film that selectively transmits nitrogen into the outer case. 4. The filter according to claim 3, wherein said filter is a nitrogen-enriched membrane.
The magnetic disk device according to the above. 5. When assembling the magnetic disk drive according to claim 3, the atmosphere inside the outer case is assembled at a pressure lower than the atmospheric pressure, and then returned to the atmospheric pressure to allow the specific gas to pass through the gas selection filter. A method for manufacturing a magnetic disk drive in which the internal pressure of an outer case is equal to the atmospheric pressure. 6. An external case having a motor for driving a magnetic disk and a magnetic head for accessing the magnetic disk and recording / reproducing information therein is provided with a filter for equalizing atmospheric pressure and atmospheric pressure inside the external case. The magnetic disk device according to claim 1, wherein the filter is a film capable of selecting a gas type to be transmitted through control by an electromagnetic field. 7. The magnetic disk drive according to claim 6, wherein said filter is a polymer / liquid crystal composite film. 8. The magnetic disk drive according to claim 6, wherein said filter is a film that does not allow oxygen molecules to pass through. 9. An external case having a motor for driving a magnetic disk and a magnetic head for accessing and recording / reproducing information by accessing the magnetic disk is provided with a filter for equalizing atmospheric pressure and atmospheric pressure inside the external case. The magnetic disk device according to claim 1, wherein the filter includes: a film that selectively transmits nitrogen to the inside of the outer case; and a film that selectively transmits nitrogen to the outside of the outer case. 10. The magnetic disk drive according to claim 9, wherein both the film for selectively transmitting nitrogen into the outer case and the film for selectively transmitting nitrogen to the outer case are nitrogen-enriched films. 11. The magnetic disk drive according to claim 9, wherein the film for selectively transmitting nitrogen into the outer case and the film for selectively transmitting nitrogen to the outside of the outer case are polymer / liquid crystal composite films. . 12. A film for selectively permeating nitrogen into the outer case and a film for selectively permeating nitrogen to the outside of the outer case, one of which is a nitrogen-enriched film, and the other is a polymer / polymer. 10. The magnetic disk drive according to claim 9, which is a liquid crystal composite film. 13. An outer case having a motor for driving a magnetic disk and a magnetic head for accessing and recording / reproducing information by accessing the magnetic disk is provided with a filter for equalizing atmospheric pressure and atmospheric pressure inside the outer case. The magnetic disk device according to claim 1, wherein the filter includes a film for selectively transmitting nitrogen into the outer case and a film for selectively transmitting oxygen to the outside of the outer case. 14. The film for selectively permeating nitrogen into the outer case is a nitrogen-enriched film, and the film for selectively transmitting oxygen out of the outer case is an oxygen-enriched film.
The magnetic disk device according to the above. 15. The film for selectively permeating nitrogen into the outer case is a polymer / liquid crystal composite film, and the film for selectively transmitting oxygen out of the outer case is an oxygen-enriched film. 14. The magnetic disk drive according to item 13. 16. The film for selectively permeating nitrogen into the outer case is a nitrogen-enriched film, and the film for selectively transmitting oxygen out of the outer case is a polymer / liquid crystal composite film. 14. The magnetic disk drive according to item 13. 17. The magnetic disk drive according to claim 13, wherein both the film for selectively transmitting nitrogen into the outer case and the film for selectively transmitting oxygen to the outer case are a polymer / liquid crystal composite film. .