JPH05242544A - Production of magneto-optical disk - Google Patents

Abstract

(57) [Summary] (Modified) [Objective] The present invention makes it possible to easily, efficiently and inexpensively manufacture a magneto-optical disk by forming a recording film on a disk substrate without using a mask plate. It is intended to provide a method. A method of manufacturing a magneto-optical disk according to the present invention comprises:
In a magneto-optical disk medium composed of a substrate and a recording film for recording information on this substrate, a recording film is formed on a substrate made of a machinable material without using a mask plate, and then the recording film is formed. Inner perimeter and / or where no membrane is required
Alternatively, the recording film formed on the outer peripheral portion is removed by cutting.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a magneto-optical disk, and more particularly to a method for manufacturing a magneto-optical disk in which a recording film is formed on a substrate without using a mask.

[0002]

2. Description of the Related Art In recent years, with the progress of information-oriented society, a recording medium of high density and large capacity is required. Therefore, it is possible to rewrite information, and the medium can be exchanged and the magneto-optical disk is portable. Is getting attention. This magneto-optical disk recording medium is supposed to have a recording film such as a dielectric film, a magnetic film, and a reflective film laminated on a substrate made of transparent plastic or glass by vacuum deposition or sputtering.

However, in order to prevent the film formation of the recording film on the substrate, the disk substrate or the film forming apparatus is provided with a substrate 11 as shown in FIGS. Is placed on the substrate support 14, and an inner peripheral mask 12 and an outer peripheral mask 13 are provided on the substrate 11 to perform masking, and a film is not formed on the mask installation site, or a target 15 and a cathode 16 are provided on the mask. Since this method is adopted, this step is complicated.

[0004]

In order to attach the mask plate to the substrate or the like, it is necessary to provide a structure for providing the mask plate on the substrate or the sputtering device. It becomes complicated and the operation rate decreases due to the increase in maintenance time.In this case, if this mask plate is made of metal, the processing cost will be high and it will not be disposable. Therefore, there is also a disadvantage that the dust generation rate at the time of film formation becomes high and the pitting corrosion of the recording film and the error rate of the medium increase.

For this reason, the metal mask plate requires periodic maintenance for cleaning it in order to suppress dust generation. For cleaning, the mask plate is immersed in an acidic liquid or sandblasted. When surface treatment is performed, moisture and foreign substances adhere to the mask plate, which significantly increases the time required to reach the vacuum, which causes composition changes, which lowers manufacturing efficiency and gradually changes the mask plate dimensions. It also has the disadvantage of affecting the quality control of the product.

When manufacturing a magneto-optical disk using a mask plate, it is considered that the mask plate is attached and detached using a robot in order to save labor and reduce dust generation. Such a robot is complicated and expensive to operate, and even when the robot is used, the mask parts contact each other when the mask plate is attached or detached, and the recording film already attached or the robot itself becomes a dust source. There is also a problem that dust is generated and adheres to the substrate, which increases the pitting corrosion and the error rate as described above, which causes quality deterioration.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a method of manufacturing a magneto-optical disk which has solved such disadvantages, and it is a magneto-optical disk comprising a substrate and a recording film for recording information on the substrate. In a disk medium, a recording film is formed on a substrate made of a machinable material without using a mask plate, and then a recording film is formed on the inner and / or outer periphery where the film formation is unnecessary. The recording film is removed by cutting.

That is, as a result of various investigations by the inventors of the present invention on various methods for solving the disadvantages in the method of manufacturing a magneto-optical disk using a mask plate, it was determined that this substrate was made of a material capable of being cut and recorded on it. After the film is formed by a known method without using a mask plate, the recording film adhering to the inner peripheral portion and / or the outer peripheral portion where the film formation is unnecessary is removed by cutting. The present invention has been completed based on the finding that a magneto-optical disk that can be manufactured can be manufactured easily and efficiently. This will be described in more detail below.

[0009]

The present invention relates to a method for manufacturing a magneto-optical disk, which is a magneto-optical disk comprising a substrate and a recording film, the substrate being made of a material capable of being cut, and a mask plate being provided on the substrate. After the recording film is formed without using it, the recording film adhered to the inner and / or outer peripheral portions, which originally do not require the formation of the recording film, is removed by cutting. According to this, the target magneto-optical disk can be easily used without the disadvantage of using a mask plate,
And the advantage that it can be manufactured efficiently.

Since the substrate used in the present invention removes unnecessary portions of the recording film formed on the substrate by cutting, a material that can be cut, for example, polycarbonate, polyolefin, polymethyl acrylate, etc. It is supposed to be made from transparent resin. This substrate has Si
A dielectric film made of N, SiC, BN, SiCN, etc., a recording film made of a transition metal and a rare earth element such as TbFeCo, a recording film made of a reflective film made of Al, etc. are formed. A known vacuum vapor deposition method or sputtering method may be used to form a film having a predetermined thickness.

According to the conventional method, however, the recording film is formed only on a predetermined portion. Therefore, a metal mask plate is installed on a portion where the film formation is unnecessary, and after the film formation, the recording film is formed. The method of removing the mask plate was carried out. However, because of the various disadvantages described above, this film formation is carried out without using the mask plate in the present invention.

Therefore, the recording film according to the present invention is formed on the entire surface of the disk substrate 1 held by the substrate holder 2 as shown in FIG. In addition to the disk substrate recording film forming portion 3 required for a magnetic disk, a disk substrate outer peripheral recording film unnecessary portion 4 and a disk substrate inner peripheral recording film unnecessary portion 5 which do not require the formation of a recording film are formed. Be filmed.

However, since the recording films formed on the disk substrate outer peripheral recording film unnecessary portion 4 and the disk substrate inner peripheral recording film unnecessary portion 5 are unnecessary portions, it is necessary to remove them. In the present invention, this unnecessary portion is then removed by cutting. This is, as shown in FIG. 1, connecting the substrate holder 2 to the lathe rotating shaft 6 and providing the cutting tool 7 on the surface thereof to rotate it. While doing so, the unnecessary portions 4 and 5 may be removed by cutting with the cutting tool 7.

In this case, as shown in FIG. 2, the disk substrate 1 may be fixed by the substrate holder 8 so that the rotation axis of the substrate and the rotation axis of the lathe may coincide with each other. It is preferable to prevent the space 10 where the light is irradiated from coming into contact with the bite. The disk substrate from which the recording film of the unnecessary portions 4 and 5 has been removed by cutting the bite has a disk substrate outer peripheral recording as shown in FIG. The target magneto-optical disk is obtained by removing the recording film from the film unnecessary portion 4 and the disk substrate inner peripheral recording film unnecessary portion 5 and forming the recording film only on the disk substrate recording film forming portion 3.

In the present invention, as described above, the recording film unnecessary portions 4, 5 in the outer peripheral portion and the inner peripheral portion of the disk substrate are used.
Since the recording film is removed by cutting with a bite or the like, the disk substrate 1 is also slightly cut at this time, but the cut of the substrate itself should be minimized.

Further, in the cutting process of the recording film unnecessary portion, cutting chips are naturally generated by the cutting, but since the chips easily adhere to the substrate due to static electricity, the chips are removed by, for example, electrostatic blow. This is often done by providing an opening near the cutting tool so that the cutting chips can pass through sufficiently, and by cutting the suction chip while suctioning the cutting chips to prevent cutting chips from adhering. Although this may be used together with the electrostatic blow described above, it is preferable to apply the resin liquid to the processed portion from which the chips have been removed for the purpose of protecting the cut surface of the recording film and improving the appearance.

[0017]

EXAMPLES Next, examples of the present invention will be given. Example As a disk substrate, a polycarbonate resin plate having a diameter of 130 mmφ and a thickness of 1.2 mm and formed with a tracking guide group is prepared, and a SiN film as a first derivative film is provided on the polycarbonate resin plate without using a mask plate. A TbFeCo film as a recording film with a thickness of 1,100 nm and then a thickness of 230 nm
And a SiN film as a second dielectric film with a thickness of 350 nm and an Al film as a reflective film with a thickness of 420 nm by sputtering respectively, and a hard coat on the reading surface. The surface was overcoated with a spin coater.

Then, the disk substrate having the recording film formed on the entire surface thereof is attached to a lathe rotating shaft 6 as shown in FIG. 1, and a single crystal diamond bite 7 is pressed against the recording film forming surface, While rotating the lathe rotary shaft 6 at 200 to 2,000 rpm, the disk 7 outer peripheral recording film unnecessary portion 4 and the disk substrate inner peripheral recording film unnecessary portion 5 which are unnecessary in this film formation are cut and processed by the cutting tool 7. When the cutting dust was removed by electrostatic blow, a magneto-optical disk as shown in FIG. 3 was obtained in which the polycarbonate substrate was also cut by 50 to 100 μm by this cutting process.

[0019]

The present invention relates to a method for manufacturing a magneto-optical disk, which, as described above, is used for forming a recording film on a disk substrate in the method for manufacturing a magneto-optical disk without using a mask plate. Then, it is characterized by cutting and removing the film formation unnecessary portion with a cutting tool etc. According to this, since the mask plate is not used, the number of steps for mounting the mask plate can be reduced, and the mask cleaning, Since a step such as degassing is also unnecessary, there is an advantage that the desired magneto-optical disk can be manufactured easily, efficiently and inexpensively.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of an apparatus for removing an unnecessary portion of a recording film according to the present invention.

FIG. 2 is a schematic vertical sectional view of another apparatus for removing a recording film unnecessary portion according to the present invention.

FIG. 3 is a plan view of a magneto-optical disk obtained according to the present invention.

FIG. 4 is a vertical sectional view of an apparatus for forming a recording film using a mask plate according to a conventional example.

FIG. 5 is another vertical cross-sectional view of an apparatus for forming a recording film using a mask plate according to a conventional example.

FIG. 6 is a further vertical sectional view of an apparatus for forming a recording film using a mask plate according to a conventional example.

[Explanation of symbols]

1, 11 ... Disk substrate, 2 ... Substrate holder,
3 ... Disk substrate recording film forming portion, 4 ... Disk substrate outer peripheral recording film unnecessary portion, 5 ... Disk base inner peripheral recording film unnecessary portion,
6 ... lathe rotary axis, 7 ... bite,
8 ... Substrate support, 9 ... Hollow part,
12 ... inner mask, 13 ... outer mask,
14 ... Substrate support, 15 ... Target,
16 ... Cathode.

Front page continuation (72) Inventor Ikuo Yoshida 3-2-1 Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa Shin-Etsu Chemical Industry Co., Ltd. Corporate Research Center No. 1 Shin-Etsu Chemical Co., Ltd. Corporate Research Center (72) Inventor Shin 2-3-1, Sakado, Takatsu-ku, Kawasaki-shi, Kanagawa Shin-Etsu Chemical Co., Ltd. Corporate Research Center

Claims (4)

[Claims] 1. In a magneto-optical disk medium comprising a substrate and a recording film for recording information on the substrate, a recording film is formed on a substrate made of a machinable material without using a mask plate, Next, a method for manufacturing a magneto-optical disk, characterized in that the recording film formed on the inner peripheral portion and / or the outer peripheral portion where the recording film is not required to be formed is removed by cutting. 2. The method for manufacturing a magneto-optical disk according to claim 1, wherein an electrostatic blow for removing cutting dust is provided in the vicinity of a cutting edge of a tool for cutting. 3. A gas inlet for sucking chips is provided in the vicinity of a cutting edge of a tool for cutting.
A method for manufacturing a magneto-optical disk described in. 4. The method of manufacturing a magneto-optical disk according to claim 1, wherein the gas suction amount is set to be larger than the discharge amount of the electrostatic blow.