JPH0827997B2 - Optical disk stamper - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to an optical disk stamper used when a large number of optical disks are copied.

<Prior Art and Its Problems> An optical disc represented by a compact disc (hereinafter referred to as a CD) is generally mass-produced by injection by forming a stamper.

The stamper is obtained by providing a resist on a glass master, performing exposure with a laser, developing, and then providing a conductive layer (Ni, Ag, etc.) on the resist by vapor deposition, and then performing Ni plating. . The stamper thus obtained has a shape having convex portions 6 forming pits, as shown in FIG. The height of the pit is 0.
The size is 1μ and the width is about 1μ, which is extremely high precision and requires high precision.

For this reason, such stampers can usually be used only for 1000 to 5000 shots due to wear and scratches on the pit surface.

<Means for Solving Problems> The present invention has been made in view of the present situation as described above, and a stamper main body made of metal having pit-shaped irregularities on the surface thereof is provided on the surface of the stamper main body. Etching a damaged surface after injection by forming a heterogeneous metal layer capable of selective etching and a different metal layer capable of selective etching adjacent to the different metal thinly and uniformly between 1 to 4 layers. The stamper for an optical disk is characterized in that a scratch-free surface is obtained by the number of layers on the stamper.

<Examples> Hereinafter, the present invention will be described in detail with reference to the drawings by one example.

First, in order to prepare the stamper of the present invention, a resist layer is provided on a glass master and exposed by a laser. Then, after development, as shown in FIG.
The developed resist 10 is left on the top. Next, according to the present invention, Mo is formed on the resist 10 by vapor deposition so as to have a thickness of 500Å. If necessary, another metal, W, may be formed by vapor deposition to a thickness of 500Å, and third and fourth layers may be further added. In this case, T
a, Cr, etc. can be used. However, on the top layer, Ni such as Cr
When a metal having a weak adhesion to plating is used, it is preferable to further add a Ni layer on the metal in order to improve the adhesion with the Ni plating.

In this way, Ni plating is performed and the desired steps are obtained to obtain the optical disk stamper according to the present invention as shown in FIG.

That is, Ni having a convex portion 6 forming a pit on the surface
On the surface of the stamper main body 4 of, W layer 12, Mo
The layer 14 is formed.

When an optical disk of about 5000 shots is normally copied using such a stamper 2, scratches and abrasion occur on the surface, and accurate copying cannot be performed.

Then, the deteriorated Mo layer 12 is removed by etching with a mixed water of ammonia water and hydrogen peroxide solution, so that the next scratch-free W layer 14 appears on the surface. This will enable a new 5000 shot press.

The W layer deteriorated after pressing is removed cleanly by etching with a mixed water of red blood salt, NaOH and water, and it is possible to newly press about 5000 shots.

In addition, generally, the metal layer formed on the stamper main body is the most preferable layer thickness of 500 to 1000Å, which is the most preferable layer thickness so that etching is not troublesome and does not damage the lower layer. To 5 layers or less is practical,
If it is more than that, the unevenness of the pit may be blurred due to the layer thickness. The material of the metal layer is not particularly limited as long as it is a dissimilar metal capable of being selectively etched with the adjacent metal layers, and the uppermost layer is a metal having a good Ni plating adhesion.

<Effects> The present invention is as described above, the life of the stamper is extended by a multiple of the number of metal films laminated on the pit surface, and further, the preservability is improved by laminating metal films having corrosion resistance and abrasion resistance. By laminating a certain metal, abrasion resistance is improved.

[Brief description of drawings]

FIG. 1 is a sectional explanatory view of a stamper showing an example of the present invention,
FIG. 2 is an explanatory view showing a stamper manufacturing process, and FIG. 3 is a sectional explanatory view showing a conventional stamper. 2 …… Stamper, 4 …… Stamper body 6 …… Pit, 8 …… Glass master 10 …… Resist, 12 …… Mo layer 14 …… W layer

Claims (1)

[Claims] 1. A stamper body made of a metal having pit-shaped irregularities on the surface thereof is provided with a dissimilar metal layer that can be selectively etched with the stamper body on the surface, and can be selectively etched with the adjacent dissimilar metal. It is characterized in that the dissimilar metal layer is thinly and uniformly formed between 1 to 4 layers to etch the scratched surface after injection and obtain a scratch-free surface by the number of layers on the stamper. Stamper for optical discs.