JP2009289338A - Magnetic recording medium and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for manufacturing a perpendicular magnetic recording medium with stable product quality by organizing a production apparatus to conduct stable surface working and a manufacturing method to install the surface working in-line immediately before a sputtering step. <P>SOLUTION: A working apparatus 3 to simultaneously work a plurality of substrates is made to synchronize with production capacity of the following step and made in-line, in a substrate working step of the perpendicular magnetic recording medium. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a magnetic recording medium mounted on various magnetic recording devices including an external recording device of a computer and a method for manufacturing the same.

  In recent years, magnetic recording media that require high recording density and low noise have been switched from the longitudinal recording method to the perpendicular recording method.

  The special feature of perpendicular recording is that there is no need for a special shape on the surface of the substrate to distribute magnetism, and that a mirror surface and a uniform substrate surface that are uniformly controlled are required to stably float the magnetic head. Many methods have been adopted to control the surface quality with low roughness and uniform surface processing by using, and to control the surface quality by batch-type substrate processing (surface polishing machine) and omit the texture process to form a magnetic film (for example, patents) Reference 1).

JP 2001-62704 A

  In perpendicular magnetic recording media that require high recording density, anisotropic processing marks and processing irregularities that occur during substrate surface processing adversely affect the orientation of the magnetic film in the sputtering process, and cause recording errors in electromagnetic conversion. It is a cause of making a defect. In addition, the flying characteristics of the magnetic head deteriorate due to processing traces and processing unevenness, and as a result, the target characteristics cannot be obtained, and defects are generated as variations in the mass production process, ensuring stable product quality. Is difficult.

  The present invention provides an apparatus and a system capable of producing a perpendicular magnetic recording medium having a stable product quality by constructing a production apparatus that performs stable surface processing and a manufacturing method in which it is configured in-line immediately before a sputtering process. It is an object.

In order to solve the above problems, the present invention realizes a surface polished surface (mirror surface with random roughness) as the substrate surface quality, and eliminates the occurrence of circumferential processing marks due to texture processing.
In addition, by reducing the size and automation of the surface polishing equipment for double-side polishing the substrate surface, the processing capacity per unit is optimized, and downtime such as pad replacement is shortened. By providing a polishing process automatically and in-line before film formation to obtain a stable surface quality, a method for producing a high-performance perpendicular magnetic recording medium is provided.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, exemplary embodiments of the invention will be described with reference to the accompanying drawings.
In the production process shown in FIG. 1, the present invention is directly connected to the subsequent process by arranging the processing machines according to the input capacity of the production line and balancing the capacity in order to perform the surface processing step in-line. A manufacturing method is provided.

  A schematic diagram of the process is shown in FIG. The surface processing machine used here is a device that uses a dedicated pad to simultaneously process both sides of the substrate to be processed. However, it is necessary to replace the pad itself with the dressing time for removing processing abrasive grains clogging the pad surface. Therefore, the number of equipment is set in consideration of downtime according to the output required for the line.

  To reduce downtime, the platen size of the processing equipment is 600 to 800 mm, preferably about 660 mm, the dressing time is 30 sec / cycle, and the pad is changed once per 24 hours. As a design, the downtime is 90 minutes or less.

  When considering the layout of the process layout, it is desirable that the size of the processing equipment be as small as possible, and because it is inlined as a pre-sputtering process for perpendicular magnetic recording media that require high recording density, it is a clean room class 100 environment. A mechanism that can automatically supply and take out a dedicated cassette is provided.

  FIG. 3 shows an outline of the processing process of the surface processing apparatus. The number of substrates to be processed simultaneously for the purpose of in-line processing is characterized by processing in units of dedicated cassettes (25 sheets) with a 2.5 inch glass substrate, and the surface processing machine automatically takes out the substrates to be processed from the dedicated cassette, After automatic supply, automatic processing, and automatic cleaning, it is automatically stored in a dedicated cassette for sending to the next process. These processes are carried out with a single device, and with regard to the washing process, it is possible to carry out washing for 5 seconds per sheet in two stages, and processing to washing in 60 seconds. It can be processed in 350 seconds or less per (25 sheets).

  6 shows an AFM image of a conventional longitudinal magnetic recording medium, and FIG. 7 shows an AFM image of the substrate surface of the perpendicular magnetic recording medium processed by the present invention.

  As shown in FIG. 4, an embodiment of the present invention is a process that realizes automatic in-line processing of a substrate processing machine, and a substrate stored in a dedicated cassette supplied to a product supply / delivery conveyor 2 is processed in an automatic line after processing. This is a production line that is supplied to a subsequent process.

  The product supply / delivery conveyor 2 is returned with a dedicated cassette containing a substrate before processing and an empty cassette after processing, and the dedicated cassette with a substrate before processing is automatically supplied to the surface processing machine 3 by automatic conveyance 1.

The process layout is composed of, for example, a width of about 2.5 m, a length of about 15 m, and about 38 m ² , and the configuration of four surface processing machines has a processing capacity of about 1,000 per hour.
The surface processing machine 3 shown in FIG. 5 is designed with, for example, about 5 m ² having a width of about 3.0 m and a depth of about 1.7 m in order to enable the above-mentioned small space and high output. As a result, it is possible to process 260 sheets per hour.

  The substrate to be processed that has entered the dedicated cassette supplied from the supply / conveyor 2 is supplied to the surface processing machine 3 by the automatic conveyance 1.

  The supply conveyor 4 of the surface processing machine 3 receives an unprocessed dedicated cassette from the automatic transfer machine, automatically supplies the substrate to be processed to the supply standby unit 5 by single wafer processing, and the empty dedicated cassette is supplied to the automatic transfer machine 1. Discharge.

  The automatic carrier 1 receives the empty dedicated cassette from the supply conveyor 4 and automatically returns it to the product supply / conveyor 2.

  The substrates to be processed supplied to the supply standby unit 5 are collected into 25 batches here, supplied to the surface polishing unit 6 by batch supply, and double-sided simultaneous polishing is performed by 25 sheets processing.

  Twenty-five substrates after processing are simultaneously moved to the discharge standby unit 7, and at the same time, unprocessed substrates are supplied from the supply standby unit 5 and the processing cycle is repeated.

  The substrate moved to the discharge standby unit 7 is supplied from here to the scrub cleaning unit 8 by single wafer processing, and two scrub cleanings are automatically performed one by one.

  The cassette storage unit 10 is composed of an immersion mechanism by submerging, and a dedicated cassette for storing 25 empty sheets is supplied from the next process by the automatic transfer system 1 and is in a standby state. The substrate after cleaning is supplied by the discharge conveyor 9 and when 25 sheets are supplied to the dedicated cassette, the substrate is moved from the cassette storage unit 10 to the automatic transfer system 1 and supplied to the next process.

  As described above, stable production of a high-quality perpendicular magnetic recording medium substrate can be realized by realizing an in-line production process according to the present invention.

1 is a process flow schematic diagram of a perpendicular magnetic recording medium of the present invention. It is a process outline figure of the present invention. It is a surface processing machine process schematic diagram. It is a layout schematic diagram of the present invention. It is a surface processing machine schematic diagram. It is a substrate surface AFM image of a conventional longitudinal magnetic recording medium. It is a substrate surface AFM image of a perpendicular magnetic recording medium processed according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automatic conveyance system 2 Product supply taking-out conveyor 3 Surface processing machine 4 Surface processing machine supply conveyor 5 Surface processing machine supply standby part 6 Surface processing machine processing part
7 Surface processing machine discharge standby section 8 Surface processing machine scrub cleaning section
9 Surface processing machine discharge conveyor 10 Cassette storage

Claims (4)

  A manufacturing method of a perpendicular magnetic recording medium, wherein in a substrate processing step of a perpendicular magnetic recording medium, a processing apparatus for simultaneously processing a plurality of substrates is in-lined in synchronization with a production capacity of a subsequent process.   2. A substrate processing machine for a perpendicular magnetic recording medium, wherein the substrate processing machine is used in the manufacturing method according to claim 1, wherein a plurality of substrates are simultaneously processed and can be inlined.   An aluminum or glass substrate for a perpendicular magnetic recording medium having a uniform and isotropic surface quality, the surface of which is processed using the substrate processing machine according to claim 2.   A magnetic recording medium using the substrate according to claim 3, wherein an adhesion layer, a soft magnetic layer, an intermediate layer, a granular magnetic layer, a protective film, and a liquid lubricant layer are sequentially laminated.