JPH05339774A - Production of stamper - Google Patents

Abstract

PURPOSE:To produce the stamper having high transfer accuracy by forming conductive layers on a duplicated disk, removing the duplicated disk from the conductive layers and using the conductive layers as a stamper. CONSTITUTION:The duplicated disk (replica) 4 is produced from an optical master disk 1. The conductive layers (Ni layers) 5, 6 consisting of a conductive material are formed on the duplicated disk 4. The duplicated disk 4 is removed from the conductive layers 5, 6. The conductive layers 5, 6 are thus formed as the stamper 7. PMMA, PC or glass is used as the substrate material for the duplicated disk. The conductive layers are formed by electroless plating on the duplicated disk. As a result, the stamper having the same rugged shape as the rugged shape of the optical master disk is produced.

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 stamper for an optical disk master having good releasability without depending on the material of the disk surface, and a method for manufacturing a stamper having the same concavo-convex shape as the optical disk master.

[0002]

2. Description of the Related Art A conventional stamper manufacturing method will be described with reference to FIG.

FIG. 2 shows a conventional stamper manufacturing method in the order of steps. In the figure, a, b, c, d
Shows the optical disc master, the first layer forming process on the optical disc master surface, the second layer forming process on the first layer, and the stamper peeling process from the optical disc master.

First, an optical disk master 1 on which a signal is recorded by forming an uneven shape on the surface of the disk master.
Then, the Ni layer 5 is formed to a thickness of about 50 to 60 nm by using a method such as a sputtering method (b). Next, Ni plating is performed using the Ni layer 5 as a cathode electrode (c). The plating thickness is about 300 μm. Next, the formed Ni plating is performed (c). The plating thickness is about 300 μm. Next, the formed Ni layers (5, 6) are peeled off from the optical disk master (d), and the back surface of the Ni layer is mirror-polished if necessary to obtain the stamper 7.

[0005]

However, the conventional N
In the i stamper manufacturing method, when the surface of the optical disc master is made of metal or the like, the optical disc master and the N formed on it are
The peelability from the i layer is poor. Further, even when peeling is possible, the dropout occurrence rate such as the deformation of the pit shape is high, and high transfer accuracy cannot be obtained.

In view of the above-mentioned problems of the prior art, the present invention is a method for manufacturing a stamper from an optical disk master that does not depend on the material of the master surface, suppresses the occurrence of dropout, and has the same unevenness as the optical disk master. An object of the present invention is to provide a method for manufacturing a stamper while suppressing the occurrence of dropout.

[0007]

In order to achieve the above object, the present invention provides a step of producing a duplicate disc (replica) from an optical disc master and a step of forming a conductive layer made of a conductive substance on the duplicate disc. , And the step of removing the duplicate disk from the conductive layer are sequentially performed to use the conductive layer as a stamper.

Preferably, in the step of forming the conductive layer on the duplicate disc, after forming a layer made of a conductive material as the first layer, a metal layer (second layer) is formed on the first layer by plating. It is desirable to form.

Preferably, at least N is used as the conductive layer.
It is desirable to use a substance containing either i (nickel) or Ti (titanium).

Preferably, it is desirable to use PC (polycarbonate) or PMMA (polymethylmethacrylate) as the substrate material of the duplicate disc in the step of producing the duplicate disc.

It is preferable to form a conductive layer made of a conductive material on the duplicate disk by electroless plating.

It is preferable that the surface of the master disk be made of metal.

[0013]

When a duplicate disc is prepared from the optical disc master by the above method and a conductive layer is formed on the duplicate disc, the adhesive force between the duplicate disc and the conductive layer is not strong. Good releasability.

As a result, it is possible to manufacture a stamper with high transfer accuracy and less dropout, regardless of the material of the surface of the optical disc master.

Further, according to the above means, the transfer process is performed an even number of times until the stamper is obtained from the optical disc master, so that it is possible to manufacture a stamper having the same unevenness as the optical disc master. At that time, the obtained stamper has high transfer accuracy and little dropout.

[0016]

The present invention will be described in detail below with reference to specific examples.

A case of manufacturing a Ni stamper for an optical disk master having a diameter of 200 mm and having a master surface made of Cu (copper) by the stamper manufacturing method of the present invention will be described.

FIG. 1 shows a method of manufacturing the stamper of this embodiment in the order of steps. In FIG. 1, a, b,
c, d, e, f are the ultraviolet curing resin dropping step,
It shows a replica manufacturing process by the photopolymer method, a replica peeling process from the optical disc master, a first layer forming process on the transfer surface, and a stamper peeling process from the replica.

First, the ultraviolet curable resin 2 is dropped and spread on the optical disc master 1 (a), and then the replica substrate 3 is formed thereon.
Then, PMMA (diameter: 200 mm, thickness: 1.2 mm) is placed on the plate, and ultraviolet rays are applied while being pressurized. As a result, the ultraviolet curable resin 2 is cured (b). The replica substrate 3 is peeled from the optical disc master 1 together with the cured ultraviolet curable resin 2 to obtain a replica 4 (c). According to this method, regardless of the material and shape of the optical disc master 1,
The shape of the optical disc master 1 can be accurately transferred.

Next, the replica 4 is formed by the sputtering method.
Ni layer 5 (first layer) of 50 to 60n on the pit transfer surface of
Form about m (c). This is because, when the second layer 6 is formed by the electrolytic plating method, the replica cannot be used as an electrode because it is an insulator, and therefore a Ni layer that is a conductive substance is formed and used as an electrode.

N formed on the pit transfer surface of the replica
Using the i layer 5 as a cathode electrode, Ni is formed by electrolytic plating.
The layer 6 (second layer) is formed with a thickness of about 300 μm (c). In this embodiment, a nickel sulfamate bath (a solution in which nickel sulfamate, nickel chloride, and boric acid are dissolved) is used as a plating bath for electrolytic plating. In this case, the formation rate of the Ni layer 6 (second layer) is about 100 μm / hr. Is.

The replica formed up to the second layer is taken out from the plating bath, and the replica and the Ni layer (first layer and second layer) are formed.
Layer) and (d) and by washing the Ni layer,
The stamper 7 can be obtained.

As described above, according to the present embodiment, the adhesive force between the replica and the Ni layer formed on the signal transfer surface of the replica is not strong, and the releasability between the duplicate disc and the Ni layer is good. Even if the master surface is made of copper, it is possible to manufacture a stamper with high transfer accuracy and less dropout.

Further, according to this embodiment, since the transfer process is performed an even number of times until the stamper is obtained from the optical disc master, it has the same unevenness as the optical disc master.
It is possible to manufacture a stamper with high transfer accuracy.

This is a very effective method especially when the optical disc master is made of metal as in this example.

In the case of this embodiment, PMMA was used as the replica substrate, but a stamper can be similarly produced by using PC or glass. Other substances that are transparent to ultraviolet rays are essentially the same and can be used as the substrate. In particular, a substance having a low coefficient of thermal expansion or a low water absorption rate is very effective because it can prevent the substrate from being deformed during the plating process.

Further, in the case of the present embodiment, the formation of the first layer or the second layer was performed by Ni, but the same treatment can be performed by using a conductive substance, and a stamper can be manufactured. You can In particular, if Ti is used for both or one of the first layer and the second layer, the strength of the stamper is improved, which is very effective.

As the method for forming the first layer, other than the sputtering method, there is no substantial change even if it is formed by a CVD method such as a vacuum deposition method or an electroless plating method. When the electroless plating method is used, the first layer is 30
If the thickness is about 0 μm, the first layer itself can be used as a stamper.

[0029]

As described above, according to the stamper manufacturing method of the present invention, it is possible to manufacture a stamper with high transfer accuracy without depending on the surface material, such as when the surface of the optical disk master is metal. Becomes

Further, according to the present invention, a stamper having the same concavo-convex shape as that of the optical disk master can be manufactured. In the case of a disc master made of metal, one method of obtaining a reproducing disc is a method of directly producing a small number of reproducing discs from the disc master by a photopolymer method or the like. In this case, the reproduction disc is obtained by performing the transfer on the disc master for an odd number of times. On the other hand, when a large number of reproduction discs are required, by performing the stamper manufacturing method of the present invention, the number of transfer times to obtain the reproduction disc on the disc master becomes an odd number. It is possible to manufacture a disk having the same concavo-convex shape as that of the disk used.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a stamper manufacturing process according to the present invention.

[Fig. 2] Conventional stamper manufacturing process diagram

[Explanation of symbols]

 1 Optical disc master 2 UV curable resin 3 Replica substrate 7 Stamper

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Kenji Takamoto, 1006 Kadoma, Kadoma City, Osaka Prefecture, Matsushita Electric Industrial Co., Ltd. (72) Toshiki Miyamoto, 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (6)

[Claims] 1. A step of producing a duplicate disc (replica) from an optical disc master, a step of forming a conductive layer made of a conductive material on the duplicate disc, and a step of removing the duplicate disc from the conductive layer. The method of manufacturing a stamper, wherein the conductive layer is a stamper. 2. In the step of forming a conductive layer on the duplicate disk, after forming a layer made of a conductive material as the first layer, a metal layer (second layer) is formed on the first layer by plating.
The method for producing a stamper according to claim 1, wherein the layer) is formed. 3. The stamper manufacturing method according to claim 1, wherein a material containing at least either Ni (nickel) or Ti (titanium) is used as the conductive layer. 4. In the step of making a duplicate disc,
The stamper manufacturing method according to claim 1, wherein PMMA (polymethylmethacrylate), PC (polycarbonate), or glass is used as the substrate material of the duplicate disk. 5. The stamper manufacturing method according to claim 1, wherein a conductive layer made of a conductive material is formed on the duplicate disk by electroless plating. 6. The stamper manufacturing method according to claim 1, wherein the surface of the master disk is made of metal.