JPH05284A - Cleaning method, parts cleaning method, cleaning liquid, processing liquid, magnetic recording medium manufacturing method, magnetic recording medium, and magnetic recording device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a cleaning liquid, a cleaning method, etc. for removing minute foreign matter adhering to the surface of a component such as a magnetic disk, and to provide a component with high cleanliness and an apparatus using the same. [Structure] By rubbing while supplying a cleaning liquid containing fine particles (16), the fine particles (16) are dispersed in the treatment liquid due to the binding energy of the fine particles (16) and high conformability at the fine surface irregularities. The fine particles (16) move the minute shavings (9) adhering to the target surface or adsorb the shavings (9) themselves to disperse the deposits in the treatment liquid. This effectively removes the adhering shavings (16) from the surface of the magnetic film 2 of the magnetic recording medium.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cleaning method, a part cleaning method, a magnetic recording medium manufacturing method, a magnetic recording medium, a magnetic recording device, a cleaning liquid, and a processing liquid, and particularly ensures high cleanliness. , A method for cleaning parts suitable for ensuring high cleanliness, a method for manufacturing a magnetic recording medium suitable for ensuring high cleanliness, a magnetic recording medium ensuring high cleanliness, The present invention relates to a magnetic recording device equipped with a magnetic recording medium of cleanliness, a cleaning liquid suitable for ensuring high cleanliness, and a processing liquid suitable for ensuring high cleanliness.

[0002]

2. Description of the Related Art A magnetic disk will be described below as an example of a manufacturing process of precision parts. In recent years, a magnetic disk device employs a coating type medium composed of high coercive force fine magnetic powder and a binder or a thin film magnetic recording medium having a large residual magnetism from the viewpoint of improving the recording density.

The general structure of a magnetic disk using a coated medium is as follows. That is, on a non-magnetic substrate, a thin film coating of a magnetic coating composed of a magnetic powder, a binder-resin and a coating film reinforcing agent, after performing a magnetic field orientation treatment and curing treatment, the surface is processed, washed, A magnetic disk is formed by forming a lubricating film.

The general structure of a magnetic disk using a thin film magnetic recording medium is as follows. That is, a non-ferromagnetic metal layer is formed on a non-magnetic substrate, a magnetic film is further formed on the non-magnetic metal layer, a protective film is formed on the magnetic film, an appropriate surface protrusion treatment is performed, and then a lubricating film is formed if necessary. It is a structure that has formed. Here, the formation of the non-ferromagnetic metal layer may be omitted.

Prior arts relating to the present invention include Japanese Examined Patent Publication No. 60-42440 and Japanese Unexamined Patent Publication No. 61-14.
There are inventions disclosed in Japanese Patent Application Laid-Open No. 8398, Japanese Patent Application Laid-Open No. 61-500351 and Japanese Patent Application Laid-Open No. 62-95400.

[0006]

As an example of the adhesion of the processed powder in the manufacturing process of precision parts, the magnetic disk manufacturing process will be described below as an example. In a situation where the recording device is required to have a large capacity, the magnetic disk must achieve high recording density and high reliability. In order to achieve high recording density, it is necessary to improve the magnetic characteristics of the magnetic medium, and it is also necessary to reduce the flying height between the magnetic disk and the magnetic head.

Therefore, in the coating type medium, fine magnetic powder having a high coercive force tends to be used. When such a fine magnetic powder is used, the amount of shavings generated when the surface of the magnetic disk is polished is small and remains on the disk surface. On the other hand, in the thin-film magnetic recording medium, it became clear that the shavings generated in the step of removing the surface protrusions have high adhesiveness due to the smoothness of the medium itself and remain on the disk surface as well.

As a result, in the coated medium and the magnetic disk, the head starts contact / stop (c).
ontact start stop, hereafter CSS
Abbreviated. ), It was found that the shavings remaining on the surface of the recording medium adhered to the surface of the head slider of the magnetic head, causing a reliability problem. Therefore, it is necessary to ensure the cleanliness of the surface of the magnetic disk, but it has been clarified that the conventional cleaning technology cannot handle it because the particle size of the shavings remaining on the surface of the magnetic disk is small.

The present invention has been made in view of the above-mentioned problems of the prior art, and is a cleaning method, cleaning liquid and processing for cleaning the shavings adhering in the manufacturing process of precision parts such as magnetic disks with high cleanliness. Provided is a magnetic disk manufacturing method which provides a liquid and enables cleaning of shavings or minute adherents adhering to the surface of a magnetic disk with high cleanliness, and a magnetic recording medium ensuring high cleanliness, and It is an object to provide a magnetic disk device equipped with this.

[0010]

To remove the shavings (or simply particles) adhering to precision parts such as magnetic disks, which is the object of the present invention, it is necessary to consider the behavior of the shavings. The reason why the shavings remain on the surface is that the surface attachment energy is high because the particle size is small. Further, since the magnetic medium itself (the precision component itself) has good smoothness, it is possible to raise the attraction force. Therefore, in order to positively remove the shavings or particles adhering to the surface, the fine particles are previously dispersed in a processing liquid such as a working grinding liquid or a cleaning liquid,
When the magnetic medium (precision component) is scraped by using the treatment liquid, the fine particles dispersed in the treatment liquid are targeted due to the binding energy of the dispersed fine particles and the high followability of the fine surface irregularities. It is possible to move the shavings or particles adhering to the surface to be adsorbed, or to adsorb the shavings or particles to disperse the adhering material in the treatment liquid and remove it from the magnetic recording medium surface (precision component surface).

[0011]

[Function] It is possible to remove shavings generated during processing and grinding of precision parts such as magnetic disks, or deposits adsorbed on the surface by scraping with a cleaning liquid in which fine particles are dispersed. .

[0012]

The present invention will be described in detail below with reference to examples in which the present invention is applied to the manufacture of magnetic disks.

Example 1 The following compositions were kneaded using a kneader and a ball mill.

Magnetic powder (Co-Fe ₂ O ₃ ) 100 parts by weight Alumina powder (α-Al ₂ O ₃ ) 10 parts by weight Epoxy resin 25 parts by weight Phenol resin 25 parts by weight Polyvinyl butyral resin 7 parts by weight Cyclohexanone 300 parts by weight Isophorone 150 parts by weight Dioxane 50 parts by weight The obtained magnetic paint was spin-coated on an aluminum substrate whose surface had been cleaned beforehand, subjected to magnetic field orientation treatment, and heat-cured to 0.3 to 0. A magnetic film having a film thickness of 9 μm was formed. Next, the magnetic film is processed to obtain a finished film thickness of 0.2 to 0.
A 6 μm magnetic disk was prepared. At this time, the finishing process was performed by a wrapping tape. The magnetic disk processed by the above method was quickly washed and dried, and then a lubricating film was formed to complete the magnetic disk. This manufacturing method is the same as the conventional magnetic disk manufacturing method.

FIG. 1 is a partial cross-sectional view of the magnetic disk and the magnetic head formed as described above. In FIG. 1, 1 is an aluminum substrate, 2 is a magnetic film, 3 is alumina particles, 4 is a lubricating film, and 5 is a magnetic head.

As a result of performing a CSS test on the magnetic disk formed as described above, it was found that deposits were generated on the head slider surface of the magnetic head 5. As a result of elemental analysis of the deposit, a magnetic medium constituent was detected. Next, the surface of the magnetic disk is scanned with a high resolution scanning electron microscope (S
As a result of observation with EM), it was confirmed that shavings of tens to hundreds of nanometers adhered to the surface of the magnetic disk. FIG. 2 is a model of deposit formation, and in FIG.
1 is an aluminum substrate, 2 is a magnetic film, 3 is alumina powder, 7 is a wrapping tape, 8 is a rubber roller, 9 is shavings attached to a magnetic disk, and 10 is a film thickness after coating. As is apparent from FIG. 2, by rubbing the surface of the magnetic film 2 with a wrapping tape through the rubber roller 8, large powder adhering to the surface of the magnetic film 2 is removed. Adhere to the surface of the magnetic film 2.

Next, the case where the cleaning process of the present invention is applied to the magnetic disk manufactured by the above-mentioned conventional method to clean it to a high degree of cleanliness will be described.

FIG. 3 is a perspective view showing a magnetic disk finishing method. In FIG. 3, 6 is a magnetic disk, 7 is a wrapping tape (or cotton tape), 8 is a rubber roller, and 15 is a processing liquid supply pipe. Shows. For cleaning the surface after processing, a cotton tape was used in the same mechanism as in FIG. 2, and a liquid in which alumina powder having an average particle size of 0.4 μm was dispersed was supplied from the treatment liquid supply pipe 15 and scraped off. 4 and 5 show the deposit removing mechanism. 4 and 5,
Reference numeral 2 is a magnetic film, 9 is an adhering shaving, and 16 is a fine particle dispersed in the treatment liquid. As shown in the figure, the fine particles 16 dispersed in the treatment liquid are the shavings 9 attached to the surface of the magnetic film 2.
Is moved, or the shavings 9 themselves are adsorbed, and this is dispersed in the treatment liquid, whereby it is removed from the surface of the magnetic recording medium. Here, the above treatment will be referred to as fine particle cleaning.

The processing conditions are shown below.

Fine particle cleaning conditions Alumina concentration 10 wt% Treatment liquid supply amount 100 cc / min Cotton tape feed 100 mm / min Pressing load 0.2 kg Heavy disc rotation speed 300 rpm Treatment time 20 sec At a magnification of 20,000 times for disc surface observation by SEM The amount of deposits present in the visual field was quantified. As a result, fine cleaning without ----- 6.3 / 24.3μm ² particles washed there ----- 0.4 / 24.3μm ² that results.

From these results, it has been clarified that the fine particle cleaning is effective in removing the submicron particles and the like adhering to the minute irregularities.

Example 2 A magnetic disk was manufactured in the same manner as in Example 1 except that the average particle diameter of alumina particles was 0.2, 0.4, 0.5 and 1.0 μm, and the disk surface was adhered by SEM. The physical quantity was evaluated. As a result, 0.2 μm −−−−− 0.28 / 24.3 μm ² 0.4 μm −−−− 0.44 / 24.3 μm ² 0.5 μm −−−−− 0.86 / 24.3 μm ² 1.0 μm −−−−− 2.6 / 24.3 μm ² No fine particle cleaning −−−− 6.3 / 24.3 μm ^{2 From these} results, it was found that the smaller the particle size, the higher the cleaning effect. . It was also confirmed that the effect was obtained even with 1.0 μm particles.

Example 3 A magnetic disk was manufactured in the same manner as in Example 1 except that alumina carbide (aluminum oxide), silicon carbide, cerium oxide, and silicon nitride were used.
The amount of deposits on the disk surface due to M was evaluated. Each particle had an average particle diameter of 0.5 μm. Consequently alumina particles ------ 0.86 / 24.3μm ² silicon carbide ------ 0.39 / 24.3μm ² cerium oxide ------ 0.57 / 24.3μm ² Silicon nitride -------- 0.48 / 24.3 [mu] m < ² > From these results, it was found that an effect other than alumina particles was also effective. It is easily conceivable that not only the materials used here but also oxides, carbides, and nitrides can be expected to be effective. Furthermore, it is conceivable that this effect can be expected for all particles.

(Embodiment 4) A nickel-phosphorus alloy is applied to a flatly finished aluminum substrate by electroless plating,
In order to obtain surface accuracy, polishing is performed using abrasive grains.
Hereinafter, this is referred to as a nickel-phosphorus substrate. This nickel-phosphorus substrate is subjected to texture processing to form processing grooves of substantially concentric circles. For texture processing, diamond particles were dispersed in a processing liquid, and the processing liquid was supplied and processed in the same manner as in Example 1 (see FIG. 3). This processing method is
It was found that the shavings can be removed from the disk surface at the same time as the processing, and as a result, scratches (defects) generated on the disk surface can be reduced. After washing and drying the texture-processed substrate by these treatments, a chromium underlayer film, a cobalt alloy magnetic film, a sputtering method,
After forming the protective film, the surface protrusions were scraped off and a lubricating film was formed to obtain a magnetic disk. If necessary, the fine particle cleaning described in Example 1 was performed to ensure high cleanliness of the magnetic disk surface. The magnetic disk using the thin film magnetic medium obtained by the above manufacturing method is
Due to the smoothness of the surface, a low flying height of the head could be achieved.

(Embodiment 5) FIG. 6 shows a schematic sectional view of a magnetic recording apparatus. In FIG. 6, the magnetic disk 6 is attached to a support 12 that is rotatable by a rotation drive mechanism 13. The magnetic head 5 is carried to a desired position on the magnetic disk 6 by the voice coil 14. These are stored in the case 11.

When the magnetic disk having the surface cleanliness obtained according to each of the above-mentioned embodiments is stored in this magnetic recording apparatus and operated under CSS conditions, the magnetic head slider portion, which is conventionally found, is not contaminated. I understood.

In each of the above embodiments, a magnetic disk was described as an example, but the present invention is not limited to this, and removal of minute foreign substances and minute removal of minute foreign particles required for electronic device parts and the like. It is clear that the present invention is also effective when applied to the removal of minute foreign matter existing on the uneven surface.

Although alumina particles, silicon carbide, cerium oxide, and silicon nitride are used as the fine particles dispersed in the treatment liquid in the above-mentioned embodiments, the present invention is not limited to this and, for example, silicon oxide is used. , Zirconium oxide,
Alternatively, a mixture of these may be used.

Further, in the above embodiment, the fine particles are dispersed in the cleaning liquid, but the same effect can be obtained by processing the fine particles dispersed in a working liquid such as lapping. Furthermore, by performing the cleaning of the present invention according to each stage of the manufacturing process of the magnetic recording medium, it becomes possible to manufacture a magnetic recording medium having higher reliability.

[0030]

According to the present invention, it is possible to obtain a precision component having a high cleanliness and a magnetic recording medium having a high surface cleanliness which secures a high recording density and high reliability. Also,
It has an effect that such a precision component and a magnetic recording medium can be easily manufactured. Furthermore, it was possible to obtain a magnetic recording device having a magnetic recording medium with high surface cleanliness, which ensured high recording density and high reliability.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view showing a magnetic disk and a magnetic head to which the present invention is applied.

FIG. 2 is a model diagram showing a state in which shavings adhere to the surface of a magnetic film during magnetic disk finishing.

FIG. 3 is a perspective view showing a magnetic disk finishing method.

FIG. 4 is a diagram showing a mechanism for removing shavings adhering to the magnetic film.

FIG. 5 is a diagram showing a mechanism for removing shavings adhering to the magnetic film.

FIG. 6 is a schematic cross-sectional view showing a state where the magnetic disk obtained in the example of the present invention is housed in a magnetic recording device.

[Explanation of symbols]

1 Al substrate 2 Magnetic film 3 Alumina powder 4 Lubrication film 5 magnetic head 6 magnetic disk 7 wrapping tape 8 rubber roller 9 Adhering shavings 10 Film thickness after application 11 cases 12 Support 13 Rotary drive mechanism 14 voice coils 15 Processing liquid supply pipe 16 Fine particles dispersed in treatment liquid

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yoshiki Kato             2880 Kozu, Odawara City, Kanagawa Stock Association             Hitachi, Ltd. Odawara factory (72) Inventor Masaki Oura             2880 Kozu, Odawara City, Kanagawa Stock Association             Hitachi, Ltd. Odawara factory (72) Inventor Mitsuyoshi Otake             292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa             Inside the Hitachi, Ltd. production technology laboratory (72) Inventor Masahiro Watanabe             292 Yoshida-cho, Totsuka-ku, Yokohama-shi, Kanagawa             Inside the Hitachi, Ltd. production technology laboratory

Claims (21)

[Claims] 1. A cleaning method characterized in that a cleaning liquid in which fine particles are dispersed is used for cleaning a minute uneven surface. 2. The cleaning method according to claim 1, wherein the fine particles have an average particle diameter of 1 micron or less. 3. The cleaning method according to claim 1, wherein the fine particles are made of aluminum oxide, silicon carbide, silicon oxide, cerium oxide, silicon nitride, zirconium oxide, or a mixture thereof. . 4. While supplying a cleaning liquid in which fine particles are dispersed,
A method for cleaning a part, which comprises scraping the surface of the part. 5. The method for cleaning a component according to claim 4, wherein the fine particles have an average particle diameter of 1 micron or less. 6. The component according to claim 4, wherein the fine particles use aluminum oxide, silicon carbide, silicon oxide, cerium oxide, silicon nitride, zirconium oxide, or a mixture thereof. Cleaning method. 7. A cleaning liquid in which fine particles are dispersed. 8. The processing liquid according to claim 7, wherein the fine particles have an average particle diameter of 1 micron or less. 9. The treatment liquid according to claim 7, wherein the fine particles use aluminum oxide, silicon carbide, silicon oxide, cerium oxide, silicon nitride, zirconium oxide, or a mixture thereof. . 10. A processing liquid in which fine particles are dispersed. 11. The processing liquid according to claim 10, wherein the fine particles have an average particle diameter of 1 micron or less. 12. The treatment liquid according to claim 10, wherein the fine particles use aluminum oxide, silicon carbide, silicon oxide, cerium oxide, silicon nitride, zirconium oxide, or a mixture thereof. . 13. A method of manufacturing a magnetic recording medium, comprising a step of scraping the surface of an object to be cleaned while supplying a cleaning liquid in which fine particles are dispersed. 14. The method of manufacturing a magnetic recording medium according to claim 13, wherein the fine particles have an average particle diameter of 1 micron or less. 15. The magnetic recording according to claim 13, wherein the fine particles use aluminum oxide, silicon carbide, silicon oxide, cerium oxide, silicon nitride, zirconium oxide, or a mixture thereof. Medium manufacturing method. 16. A magnetic recording medium manufactured by a manufacturing method comprising a step of scraping the surface of an object to be cleaned while supplying a cleaning liquid in which fine particles are dispersed. 17. The magnetic recording medium according to claim 16, wherein the fine particles have an average particle diameter of 1 micron or less. 18. The magnetic recording according to claim 16, wherein the fine particles use aluminum oxide, silicon carbide, silicon oxide, cerium oxide, silicon nitride, zirconium oxide, or a mixture thereof. Medium. 19. A magnetic recording apparatus comprising a magnetic recording medium manufactured by a manufacturing method including a step of scraping the surface of a magnetic film while supplying a cleaning liquid in which fine particles are dispersed. 20. The magnetic recording apparatus according to claim 19, wherein the fine particles have an average particle diameter of 1 micron or less. 21. The magnetic recording according to claim 19, wherein the fine particles use aluminum oxide, silicon carbide, silicon oxide, cerium oxide, silicon nitride, zirconium oxide, or a mixture thereof. apparatus.