JP2009163802A - Magnetic disk manufacture assistance method and method of manufacturing magnetic disk - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a magnetic disk manufacture assistance method capable of improving yield of a magnetic disk by preventing adhesion of dust and a foreign matter to a glass substrate just before putting in a clean room and forming a magnetic layer on the glass substrate which is not contaminated by particles and to provide a manufacturing method of a magnetic disk. <P>SOLUTION: The magnetic disk manufacture assistance method for assisting manufacture of the magnetic disk manufactured from the glass substrate 100 for the magnetic disk doubly packed by using first and second packing bags includes: a first opening step of opening the first packing bag 210 in a first room 310; a second opening step of opening the second packing bag 220 in a second room 320; and a carrying step of carrying the glass substrate for the magnetic disk in the clean room 330. In the first and the second opening steps, an air flow is made to flow from the second room to the first room. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a magnetic disk manufacturing support method and a magnetic disk manufacturing method.

  In recent years, with the advancement of information technology, information recording technology, particularly magnetic recording technology, has made remarkable progress. As a substrate for magnetic recording media such as HDD (Hard Disk Drive), which is one of the magnetic recording media, a substrate replacing the aluminum substrate that has been widely used with the miniaturization, thinning, and high-density recording of magnetic disks. A glass substrate excellent in surface flatness and substrate strength has been used.

  As the magnetic recording technology increases in density, the magnetic head has been changed from a thin film head to a magnetoresistive head (MR head) and a giant magnetoresistive head (GMR head). The flying height from the center is narrowed to about 20 nm to 5 nm. A magnetic head equipped with such a magnetoresistive element may cause a head crash failure or a thermal asperity failure as an inherent failure. Since these obstacles are caused by minute irregularities on the surface of the magnetic disk, the surface of the magnetic disk is required to have extremely high smoothness and flatness.

  As described above, the glass substrate for a magnetic disk in which smoothness and flatness are important does not like that particles due to dust adhere to the surface of the glass substrate and are contaminated. This is because when a magnetic layer is formed on a glass substrate to which particles are attached, a convex defect including particles is formed on the surface of the magnetic disk, which causes head crash injury and thermal asperity failure. Therefore, the operation of forming the magnetic layer on the surface of the glass substrate is usually performed in a clean room. Here, there is a problem of particles adhering to the glass substrate while the manufactured glass substrate is transported to the clean room.

  In order to prevent the adhesion of such particles, the manufactured glass substrate is stored in a storage container, for example, double-packed with a first packing bag and a second packing bag, and then a magnetic disk manufacturing facility with a clean room (For example, Patent Document 1). At this time, since the glass substrate is sealed in the packaging bag, it is possible to prevent intrusion of particles and foreign matters into the packaging bag.

For example, a technique for preventing contamination of a glass substrate during transportation using a packaging bag made of a material such as that disclosed in Patent Document 2 has been proposed. In Patent Document 2, the glass substrate is hermetically packaged together with the holder by a packaging member having a water vapor transmission rate of 5 g / m ² · day or less, thereby preventing deterioration of the main surface of the glass substrate during transportation or storage. Yes.
Japanese Patent Laid-Open No. 11-157591 JP 2001-240178 A

  However, as disclosed in Patent Document 1 or Patent Document 2, only by devising a packaging method during transportation, the glass substrate may be contaminated when unpacking and carrying the glass substrate into a clean room. . The packed glass substrate may be transported by ship, airplane, train, etc., and is placed in a dusty space or exposed to the outside air, so particles and foreign substances adhere to the packing bag during delivery. To do. Such particles may contaminate the glass substrate that has been protected from contamination during transportation immediately before entering the clean room.

  In the magnetic disk manufacturing process, cleaning is first performed as a glass substrate receiving operation. Therefore, it was thought that there was no big problem even if particles adhered to the unpacked glass substrate. However, even if cleaning is performed in the receiving operation, not all particles can be removed. Therefore, if there are many particles adhering from the beginning, the amount of particles remaining on the substrate surface also increases. Moreover, there is a possibility that particles adhering to the substrate surface may be damaged on the substrate surface during cleaning. Furthermore, with the further increase in recording density in the future, small convex defects and concave defects (scratches), which were not a problem in the past, are no longer allowed. Therefore, a smooth magnetic layer cannot be formed on the glass substrate in the film forming process, and the yield rate of the final magnetic disk is reduced.

  In view of such problems, the present invention prevents the adhesion of dust and foreign matter to the glass substrate immediately before entering the clean room, and forms a magnetic layer on the glass substrate that is not contaminated with particles, thereby yielding the magnetic disk. It is an object of the present invention to provide a magnetic disk manufacturing support method and a magnetic disk manufacturing method capable of improving the above.

  As a result of intensive studies on the method for removing particles and foreign substances in the unpacking process by the inventors of the present application, the unpacking method immediately before bringing the double-packed glass substrate into the clean room and the environment of the room for unpacking are improved. This prevents particles and foreign substances from adhering to the glass substrate immediately before the film formation process, forms a smooth magnetic layer on the glass substrate in the film formation process, and consequently improves the yield rate of the final magnetic disk. The headline and the present invention were completed.

  In order to solve the above problems, a typical configuration of a magnetic disk manufacturing support method according to the present invention is a magnetic disk manufactured from a glass substrate for a magnetic disk that is double-packed in first and second packing bags. In the magnetic disk manufacturing support method for supporting the manufacturing of the first, the first unpacking step of unpacking the first packing bag in the first chamber and the second unpacking of unpacking the second packing bag in the second chamber. Including a bundling process and a loading process of loading the magnetic disk glass substrate into the clean room, and in the first unpacking process and the second unpacking process, air flows from the second chamber toward the first chamber. It is characterized by.

  With this configuration, most of the particles and foreign matter adhering to the outer first packing bag during transportation can be removed when the first packing bag is opened in the first chamber, and the second chamber Reduces the amount of particles and foreign objects brought into the final clean room compared to unpacking the first and second packaging bags in the same room. It becomes possible. In addition, by flowing an air flow from the second chamber to the first chamber, particles and foreign matter scattered in the first chamber are prevented from entering the second chamber, and the glass substrate is still packed inside. It is possible to prevent the dust and foreign matter from adhering to the second packing bag. Thus, if the 2nd packing bag protected from adhesion of dust is opened in the 2nd chamber immediately before a clean room, the number of particles adhering to a glass substrate will reduce markedly. Therefore, the yield of the magnetic disk can be improved.

  Another configuration of the magnetic disk manufacturing support method according to the present invention is a magnetic disk manufacturing support that supports manufacturing of a magnetic disk manufactured from a glass substrate for a magnetic disk that is double-packed in the first and second packing bags. In the method, a first unpacking step of unpacking the first packing bag in the first chamber, a second unpacking step of unpacking the second packing bag in the second chamber, and a magnetic disk glass substrate And a loading step of loading the sample into a clean room, wherein the pressure in the second chamber is higher than the pressure in the first chamber.

  With this configuration, it is possible to generate an air flow from the second chamber toward the first chamber. Therefore, as described above, it is possible to prevent the particles or foreign matter scattered in the first chamber from entering the second chamber during the first unpacking step.

  The above airflow may be flowed by a fan. By using the fan, an air flow can be forcibly generated from the second chamber toward the first chamber.

  The pressure in the second chamber may be set higher than the pressure in the first chamber by pressurization using an air compressor (compressor).

  By making the pressure in the second chamber higher than the pressure in the first chamber using an air compressor, an air flow from the second chamber toward the first chamber can be generated. The pressure in the first chamber is preferably lower than the pressure in the second chamber by reducing the pressure using a decompressor.

  By making the pressure in the first chamber lower than the pressure in the second chamber using the decompressor, as described above, an air flow from the second chamber to the first chamber can be generated.

  In order to solve the above-described problems, a magnetic disk manufacturing method according to the present invention performs a film forming process for forming at least a magnetic layer on the surface of a glass substrate unpacked by the above-described manufacturing support method for a magnetic disk. It is characterized by that.

  The above-described components based on the technical idea of the magnetic disk manufacturing support method and the description thereof can also be applied to the magnetic disk manufacturing method.

  According to the present invention, it is possible to improve the yield of magnetic disks by preventing the adhesion of dust and foreign matter to the glass substrate immediately before entering the clean room, and forming the magnetic layer on the glass substrate that is not contaminated with particles. It is possible to provide a magnetic disk manufacturing support method and a magnetic disk manufacturing method that can be used.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The dimensions, materials, and other specific numerical values shown in the embodiment are merely examples for facilitating understanding of the invention, and do not limit the present invention unless otherwise specified. In the present specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals, and redundant description is omitted, and elements not directly related to the present invention are not illustrated. To do.

  First, the glass substrate for magnetic disks according to this embodiment will be described. FIG. 1 is a view for explaining a glass substrate for a magnetic disk according to the present invention, and FIG. 1 (a) is a perspective view of the glass substrate for a magnetic disk. The magnetic disk glass substrate 100 has a disk shape, and an inner hole is formed at the center thereof. Since the main surface 110 is an area for recording and reproducing information, the main surface 110 is substantially smooth for the recording head to fly.

  FIG.1 (b) is XX sectional drawing of Fig.1 (a). The magnetic disk glass substrate 100 is interposed between a main surface 110 serving as an information recording / reproducing area, an end surface 120 orthogonal to the main surface 110, and the main surface 110 and the end surface 120. And a chamfered surface 130. In addition, since the boundary between the end surface 120 and the chamfered surface 130 may become unclear due to an end surface polishing process described later, in the present embodiment, the end surface 120 and the chamfered surfaces 130 on both sides constitute a single curved surface. Including the case of doing.

  If particles or foreign matter adhere to the magnetic disk glass substrate 100, particularly its main surface 110, before the magnetic disk film forming process, a smooth magnetic layer cannot be formed on the glass substrate in the film forming process, and the final product The yield rate of a certain magnetic disk is reduced.

  FIG. 2 is a diagram illustrating a state in which the glass substrate is stored in the case. FIG. 2A is an enlarged view of a plastic substantially rectangular parallelepiped glass substrate case which is a container for storing a glass substrate. The case 200 can store 25 glass substrates, and the glass substrate 100 is stored in the case 200. A plurality of cases 200 in which the glass substrates 100 are housed can be stacked as shown in FIG.

  FIG. 3 is a diagram for explaining a packing state of the case in which the glass substrate is stored. The case 200 in which the glass substrate 100 is housed is removed by a second packing bag 220 made of an aluminum laminate film in a state where a plurality of (in this embodiment, four) cases as shown in FIG. The package is hermetically packaged with care, resulting in a package 222 shown in FIG.

  After that, the first packing bag 210 made of plastic film is hermetically packed with or without deaeration, resulting in a double packing body 212 shown in FIG. This plastic film may be, for example, polyethylene. In the present embodiment, a plurality of cases 200 are packed in a stacked state. However, each case 200 may be packed.

  Next, the magnetic disk manufacturing support method according to the present embodiment will be described.

  The glass substrate 100 packed as described above is shipped from the glass substrate manufacturing facility and transported to the magnetic disk manufacturing facility. After arriving at the magnetic disk manufacturing facility, the unpacking process is performed.

  FIG. 4 is a diagram illustrating a chamber in which an unpacking process is performed. The film forming process is performed on a production line installed in the clean room 330. The room adjacent to the clean room 330 is the second room 320 for unpacking the second packing bag, and the room adjacent to the opposite side of the clean room 330 of the second room 320. Is a first chamber 310 for unpacking the first packing bag.

  The double-packed glass substrate 100, that is, the double-packed body 212 is carried into the first chamber 310. Then, the outer first packing bag 210 is unpacked in the first unpacking step, and the packing body 222 is packed with only the second packing bag 220. The package 222 is carried into the second chamber 320, and the second packaging bag 220 is unpacked in the second unpacking step. Thereafter, the glass substrate 100 is carried into the clean room 330 in a carrying-in process described later in a state where the packaging bag is removed and stored in the case 200.

  With this configuration, even if particles or foreign matter adhering to the first packing bag 210 are scattered in the first chamber 310, the second packing bag 220 is unpacked in the second chamber 320. It is possible to prevent adhesion of particles and foreign matters to the glass substrate 100 when the second packing bag 220 is unpacked. In addition, since the second chamber 320 is provided between the first chamber 310 and the clean room 330, it is possible to prevent particles and foreign substances from entering the clean room 330.

  Further, in FIG. 4, a fan 340 is installed in the first chamber 310, and an air flow is generated by discharging the air in the first chamber 310 to the outside, and the second chamber 320 moves to the first chamber 310. Air is flowing in. As described above, by generating an air flow from the second chamber 320 toward the first chamber 310, particles and foreign matters adhering to the first packing bag 210 are scattered in the first chamber 310. In addition, it is possible to reduce intrusion of particles and foreign substances from the first chamber 310 to the second chamber 320.

  In this embodiment, the fan 340 is installed in the first chamber 310, but the fan 340 is installed in the second chamber 320 or both the first chamber 310 and the second chamber 320. Also good. Further, as another means for generating the above-described air flow, there is a method of providing a difference in height between the pressure in the first chamber 310 and the second chamber 320. At this time, the pressure in the second chamber 320 is set to be higher than the pressure in the first chamber 310. Examples of a method for providing such a height difference include a method of pressurizing the pressure in the second chamber 320 using an air compressor, and a method of reducing the pressure in the first chamber 310 using a decompressor.

  As described above, according to the magnetic disk manufacturing support method according to the present embodiment, it is possible to prevent particles and foreign matter from adhering to the glass substrate during the unpacking process and to prevent particles and foreign matter from entering the clean room. Can do. Therefore, it is possible to improve the yield of the magnetic disk by forming a smooth magnetic layer on the glass substrate in the film forming process.

(Example)
Embodiments of a magnetic disk manufacturing support method and a magnetic disk manufacturing method to which the present invention is applied will be described below. The glass substrate 100 for magnetic disk and the magnetic disk are 0.8 inch type disk (inner diameter 6 mm, outer diameter 21.7 mm, plate thickness 0.381 mm), 1.0 inch type disk (inner diameter 7 mm, outer diameter 27.4 mm). , Plate thickness 0.381 mm), 1.8 inch type magnetic disk (inner diameter 12 mm, outer diameter 48 mm, plate thickness 0.508 mm) and the like. Further, it may be manufactured as a 2.5 inch type disc or a 3.5 inch type disc.

(1) Shape processing step and first lapping step Examples of the material of the glass substrate 100 in this embodiment include soda lime glass, aluminosilicate glass, borosilicate glass, and crystallized glass. Among these, aluminosilicate glass is preferable. is there. Since the aluminosilicate glass is smooth and has high rigidity, the magnetic spacing, particularly the flying height of the magnetic head, can be more stably reduced. Aluminosilicate glass can obtain high rigidity and strength by chemical strengthening.

First, the melted aluminosilicate glass was molded into a disk shape by direct pressing using an upper mold, a lower mold, and a barrel mold to obtain an amorphous plate glass. In addition, the glass for chemical strengthening was used as aluminosilicate glass. In addition to direct pressing, a disk-shaped glass substrate 100 for a magnetic disk may be obtained by cutting a sheet glass formed by a downdraw method or a float method with a grinding wheel. As the aluminosilicate _glass, SiO 2: 58 to 75 _{wt%, Al} 2 O 3: _{5~23 wt%,} Li 2 O: 3 to 10 _wt%, Na 2 O: 4 to 13 principal component weight% The chemically strengthened glass contained as was used.

  Next, both main surfaces of the plate glass were lapped to form a disk-shaped glass base material. This lapping process was performed using alumina free abrasive grains with a double-sided lapping apparatus using a planetary gear mechanism. Specifically, the lapping platen is pressed from above and below on both sides of the plate glass, a grinding liquid containing free abrasive grains is supplied onto the main surface of the plate glass, and these are moved relatively to perform lapping. went. By this lapping process, a glass base material having a flat main surface was obtained.

(2) Cutting process (coring, forming)
Next, the glass base material was cut using a diamond cutter, and a disk-shaped glass substrate was cut out from the glass base material. Next, using a cylindrical diamond drill, an inner hole was formed in the central portion of the glass substrate to obtain an annular glass substrate 100 (coring). Then, the inner peripheral end face and the outer peripheral end face 120 were ground with a diamond grindstone and subjected to predetermined chamfering (forming).

(3) Second Lapping Step Next, the second lapping process was performed on both main surfaces 110 of the obtained glass substrate 100 in the same manner as in the first lapping step. By performing this second lapping step, the fine irregularities formed on the main surface in the cutting step and end surface polishing step, which are the previous steps, can be removed in advance, and the subsequent polishing step for the main surface 110 can be performed. It can be completed in a short time.

(4) End surface polishing step Next, end surface polishing of the outer periphery of the glass substrate 100 is performed. First, the end surface 120 is polished independently prior to the chamfered surface 130. The polishing method may be, for example, a method in which a plurality of glass substrates 100 are simultaneously polished with a brush, but the machining allowance increases. Therefore, for example, a single wafer polishing method may be used.

  Subsequently, the chamfered surface 130 was mirror-polished. Thereby, the difference of the surface roughness in the perimeter of the outer periphery of the chamfered surface 130 of one glass substrate 100 became the range of 0.001 micrometer or less. And the glass substrate 100 which finished the end surface grinding | polishing process was washed with water. By this end face polishing step, the end face 120 of the glass substrate 100 was processed into a mirror state that can prevent the precipitation of sodium and potassium.

  In this embodiment, it has been described that the chamfered surface 130 is polished after the end portion is polished. However, this order is arbitrary, and the end face 120 may be polished after the chamfered surface 130 is polished first.

  Next, regarding the inner peripheral end surface, a glass substrate block in which a large number of sheets are laminated may be formed, and the chamfered inner peripheral end portion may be simultaneously polished with a brush roll. At this time, as the abrasive grains, a slurry (free abrasive grains) containing cerium oxide abrasive grains was used.

(5) Main surface polishing step As the main surface polishing step, first, a first polishing step was performed. The first polishing step is mainly intended to remove scratches and distortions remaining on the main surface 110 in the lapping step described above. In the first polishing step, the main surface 110 was polished using a hard resin polisher by a double-side polishing apparatus having a planetary gear mechanism. As the abrasive, cerium oxide abrasive grains were used.

  The glass substrate 100 which finished this 1st grinding | polishing process was immersed in each washing tank of neutral detergent, a pure water, and IPA (isopropyl alcohol) sequentially, and was wash | cleaned.

  Next, a second polishing step was performed as the main surface polishing step. The purpose of the second polishing step is to finish the main surface 110 in a mirror shape. In the second polishing step, mirror polishing of the main surface 110 was performed using a soft foam resin polisher by a double-side polishing apparatus having a planetary gear mechanism. As the abrasive, cerium oxide abrasive grains finer than the cerium oxide abrasive grains used in the first polishing step were used.

  The glass substrate 100 which finished this 2nd grinding | polishing process was immersed in each washing tank of neutral detergent, a pure water, and IPA (isopropyl alcohol) one by one, and was wash | cleaned. Note that ultrasonic waves were applied to each cleaning tank.

(6) Chemical strengthening process Next, the glass substrate 100 which finished the above-mentioned lapping process and polishing process was chemically strengthened. For chemical strengthening, a chemical strengthening solution prepared by mixing potassium nitrate (60%) and sodium nitrate (40%) is prepared, and the chemically strengthened solution is heated to 400 ° C. and the cleaned glass substrate 100 is heated to 300 ° C. This was done by preheating and immersing in a chemical strengthening solution for about 3 hours. In this immersion, in order to chemically strengthen the entire surface of the glass substrate 100, the plurality of glass substrates 100 were stored in a holder so that the glass substrate 100 was held by the end surface 120.

  Thus, by immersing in the chemical strengthening solution, the lithium ions and sodium ions in the surface layer of the glass substrate 100 are replaced with sodium ions and potassium ions in the chemical strengthening solution, respectively, and the glass substrate 100 is strengthened. The thickness of the compressive stress layer formed on the surface layer of the glass substrate 100 was about 100 μm to 200 μm.

  The glass substrate 100 that had been subjected to the chemical strengthening treatment was immersed in a water bath at 20 ° C. for rapid cooling and maintained for about 10 minutes. And the glass substrate 100 which finished quenching was immersed in the concentrated sulfuric acid heated at about 40 degreeC, and was wash | cleaned. Furthermore, the glass substrate 100 that had been subjected to the sulfuric acid cleaning was sequentially immersed and cleaned in each cleaning tank of pure water and IPA (isopropyl alcohol). In addition, ultrasonic waves were applied to each cleaning tank.

  As described above, by applying the first lapping step, the cutting step, the end surface polishing step, the second lapping step, the first and second polishing steps, and the chemical strengthening step, a flat and smooth high-rigidity magnetic disk glass A substrate 100 was obtained.

(7) Inspection Step The main surface 110 of the obtained magnetic disk glass substrate 100 was inspected for smoothness. The inspection process uses light such as a surface defect detector (AOI: Automatic Optical Inspection) and an OSA (Optical Surface Analyzer) to irradiate the magnetic disk glass substrate 100 with light and reflect the light from the magnetic disk glass substrate 100. One or both of the strength and displacement of the substrate is measured, whether or not there are deposits, concave portions and convex portions is measured, and the substrate state is evaluated.

(8) Packing process 25 magnetic disk glass substrates 100 are accommodated in a case 200, four cases 200 are stacked, placed in a second packing bag 220 made of an aluminum laminate film, and the inside of the second packing bag 220 is filled. It was sealed and packaged under reduced pressure to obtain a package 222. Next, the packing body 222 was put in a first packing bag 210 made of a plastic film, and the first packing bag 210 was hermetically packed while decompressing to form a double packing body 212. Thus, by double-packing while sealing the glass substrate 100, the permeation of water vapor and gas into the packaging bag is effectively prevented, preventing the water vapor and gas from contacting the glass substrate 100, and being delivered. It becomes possible to keep the quality of the glass substrate 100 in a good state.

  As described above, the double packing body 212 in which the glass substrate 100 is housed in the case 200 and double-sealed and packed in the first packing bag 210 and the second packing bag 220 is shipped from the glass substrate manufacturing facility. They were transported to a magnetic disk manufacturing facility by ship, airplane or train. The details of the magnetic disk manufacturing support process and the magnetic disk manufacturing process performed at the magnetic disk manufacturing facility will be described below.

(9) First Unpacking Step Of the double packing bags of the double packing body 212, the first packing bag 210, which is the outer packing bag, is unpacked in the first chamber 310 to obtain a packing body 222. . The first chamber 310 is adjacent to the second chamber 320, and airflow flows from the second chamber 320.

(10) Second unpacking step The second packing bag 220 of the packing body 222 was unpacked in the second chamber 320. The second chamber 320 is adjacent to the first chamber 310 and the clean room 330 where the production line is installed, and an air flow is generated toward the first chamber 310.

(11) Carrying-in process In order to perform the film-forming process which forms a magnetic layer on the glass substrate 100, the glass substrate 100 accommodated in case 200 is conveyed to the clean room 330 where the production line is installed.

[Evaluation]
The effectiveness of the present embodiment in the glass substrate unpacked by the manufacturing support process will be described. The effectiveness is verified by the number of particles. In FIG. 5 described later, 100 glass substrates were counted by the surface defect detection device, and the average value was defined as “number of particles”.

  FIG. 5 is a diagram showing the results of counting the number of particles in the example and the comparative example. Here, the embodiment means that a fan is used to forcibly flow an air flow from the second chamber toward the first chamber, the first unpacking step is performed in the first chamber, and the second unpacking step is performed in the first chamber. In the case where the first unpacking step and the second unpacking step are performed in the same chamber, the comparative example 2 is performed between the first chamber and the second chamber. When the first unpacking process is performed in the first chamber and the second unpacking process is performed in the second chamber, the comparative example 3 uses the fan in the reverse direction, that is, the first chamber. This is a case where the air flow is forced to flow from the first chamber to the second chamber, the first unpacking step is performed in the first chamber, and the second unpacking step is performed in the second chamber.

  As shown in FIG. 5, the number of particles in the example is significantly smaller than the number of particles in Comparative Example 1, Comparative Example 2, and Comparative Example 3. As such a cause, since the first unpacking step and the second unpacking step are performed in the same chamber in Comparative Example 1, particles and foreign matter adhered to the outer first packing bag during the first unpacking step It is considered that particles and foreign matters adhere to the glass substrate when the inner second packaging bag is unpacked in the second unpacking step. In addition, if the room where the first unpacking process and the second unpacking process are performed is adjacent to the clean room, particles and foreign matter adhering to the second packing bag scattered inside the room may be brought into the clean room. Conceivable.

  The reason for the large number of particles in Comparative Example 2 is that there is no flow of airflow between the first chamber and the second chamber, so particles and foreign matter scattered in the first chamber during the first unpacking process Since it is easily brought into the chamber, the amount of particles and foreign matters in the second chamber cannot be reduced, and it is considered that particles and foreign matters adhere to the glass substrate during the second unpacking step. However, the number of particles is smaller than in Comparative Example 1. Thus, under the common condition of no air flow, it can be seen that unpacking each double-packed bag in a separate chamber clearly improves the results than in the same chamber.

  In Comparative Example 3, the number of particles is the largest. The cause is that air current flows from the first chamber to the second chamber, so that when the first packing bag is packed, particles and foreign matter scattered in the first chamber get on the air current and flow into the second chamber. Flow into. Therefore, most of the particles and foreign matter scattered in the first chamber are brought into the second chamber, so when the second packing bag is unpacked in the second unpacking process, a large amount of particles and foreign matters are It is thought to adhere to the substrate. In addition, since the airflow is flowing from the first chamber toward the second chamber, the particles and foreign matters that are on the airflow are adjacent to the second chamber on the opposite side of the first chamber. It is also conceivable that the amount of particles and foreign matters in the clean room will increase by reaching the point.

  From the above results, by flowing an air stream from the second chamber toward the first chamber, particles or particles on the glass substrate after being brought into the clean room where the production line is installed, that is, immediately before the film forming step, It can be seen that adhesion of foreign matter can be prevented. As a result, a smooth magnetic layer can be formed on the glass substrate during the film forming process, and as a result, the yield of the magnetic disk can be improved.

(12) Magnetic disk manufacturing process (film formation process)
On both surfaces of the glass substrate 100 obtained through the manufacturing process and the manufacturing support process described above, an adhesion layer made of a Cr alloy, a soft magnetic layer made of a CoTaZr-based alloy, an underlayer made of Ru, and a CoCrPt group on the surface of the glass substrate 100 A perpendicular magnetic recording disk was manufactured by sequentially forming a perpendicular magnetic recording layer made of an alloy, a protective layer made of hydrogenated carbon, and a lubricating layer made of perfluoropolyether. Although this configuration is an example of a configuration of a perpendicular magnetic disk, a magnetic layer or the like may be configured as an in-plane magnetic disk.

  As mentioned above, although the suitable Example of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to this Example. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  The present invention can be used in a magnetic disk manufacturing support method and a magnetic disk manufacturing method.

It is a figure explaining the glass substrate for magnetic discs concerning this invention. It is a figure explaining the accommodation state to the case of a glass substrate. It is a figure explaining the packing state of the case in which the glass substrate was accommodated. It is a figure explaining the chamber which performs an unpacking process. It is a figure which shows the result of the particle number in an Example and a comparative example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Glass substrate (for magnetic discs) 110 ... Main surface 120 ... End surface 130 ... Chamfering surface 200 ... Case 210 ... First packing bag 212 ... Double packing body 220 ... Second packing bag 222 ... Packing body 310 ... First chamber 320 ... Second chamber 330 ... Clean room 340 ... Fan

Claims (4)

In a magnetic disk manufacturing support method for supporting the manufacture of a magnetic disk manufactured from a glass substrate for a magnetic disk that is double-packed in a first and a second packing bag,
A first unpacking step of unpacking the first packing bag in the first chamber;
A second unpacking step of unpacking the second packing bag in a second chamber;
A loading step of loading the glass substrate for magnetic disk into a clean room;
Including
In the first unpacking step and the second unpacking step, a magnetic disk manufacturing support method is characterized in that an air flow is caused to flow from the second chamber toward the first chamber. In a magnetic disk manufacturing support method for supporting the manufacture of a magnetic disk manufactured from a glass substrate for a magnetic disk that is double-packed in a first and a second packing bag,
A first unpacking step of unpacking the first packing bag in the first chamber;
A second unpacking step of unpacking the second packing bag in a second chamber;
A loading step of loading the glass substrate for magnetic disk into a clean room;
Including
The magnetic disk manufacturing support method, wherein the pressure in the second chamber is higher than the pressure in the first chamber.   3. The magnetic disk manufacturing support method according to claim 2, wherein the pressure in the first chamber is made lower than the pressure in the second chamber by reducing the pressure using a decompressor.   A method of manufacturing a magnetic disk, comprising performing a film forming step of forming at least a magnetic layer on a glass substrate for a magnetic disk unpacked by the method according to any one of claims 1 to 3.

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