JPH0890565A - Regeneration of stamper for molding disk - Google Patents

Abstract

PURPOSE: To reutilize a stamper having unevenness generated on the contact surface with a mold thereof by a simple technique. CONSTITUTION: After the contact surface with a mold of a stamper 4 is smoothed by grinding, a plating film M is formed on the smoothed surface of the stamper 4 to exclude the unevenness 4a generated on the surface of the stamper 4 to compensate the thickness and strength of the stamper 4. By this constitution, the stamper 4 can be reutilized and the cost load in the replacement of the stamper 4 can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for reproducing a stamper used for molding a substrate such as an optical disk.

[0002]

2. Description of the Related Art FIG. 3 shows a conventional disk molding die of this type. In the figure, 1 is a fixed type, 2 is a sprue bush, 3 is a movable type, 4 is a stamper, 5 is an inner ring, 6 is an outer ring, and 7 is an ejector pin.

The stamper 4 is for transferring a predetermined groove to the disk, is made of nickel or its alloy, and has a spiral or concentric projection on its surface. The stamper 4 is placed on the mirror surface 3a of the movable die 3, and its inner and outer peripheral edges are held by the inner peripheral ring 5 and the outer peripheral ring 6.

The outer peripheral ring 6 plays a role of defining the outer diameter of the disk. In the mold closed state, the mirror surface 1a of the fixed mold 1, the stamper 4, and the inner and outer peripheral rings 5, 6 define a disk-shaped cavity. .

[0005]

It is said that the number of durable shots of the stamper 4 used for disk molding is usually several tens to tens of thousands. However, as shown in FIG. 4, it is between the stamper 4 and the mirror surface 3a. When foreign matter A such as dust enters, irregularities are generated on the back surface of the stamper after only a few shots, which appear on the disk side and cause defective molding.

The present invention has been made in view of the above problems, and provides a method of remanufacturing a stamper for molding a disk, which allows a stamper having a surface on the side in contact with a mold to be reused by a simple method. To provide.

[0007]

In order to achieve the above object, the invention of claim 1 is a method of regenerating a stamper used in molding a disk, wherein a surface of the stamper which is in contact with the mold is polished to be smooth. It is characterized by forming a plating film on the same surface after conversion.

According to a second aspect of the present invention, there is provided a method for remanufacturing a stamper used for molding a disk, which comprises forming a plating film on the surface of the stamper which is in contact with the mold, and polishing the surface of the plating film to smooth it. It is characterized by becoming.

[0009]

According to the first aspect of the present invention, the surface of the stamper that is in contact with the mold is polished and smoothed, and then a plating film is formed on the same surface to eliminate irregularities and to improve the stamper thickness and strength. Can be supplemented.

According to the second aspect of the present invention, a plating film is formed on the surface of the stamper die which is in contact with the mold, and the surface of the plating film is polished and smoothed to eliminate irregularities, and the stamper thickness and The strength can be supplemented.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A stamper regenerating method according to the present invention will be described below with reference to FIG.
Will be explained.

FIG. 1 shows a first reproducing method. First, the inner and outer peripheral rings 5 and 6 are removed, and the stamper 4 having irregularities 4a on the back surface is taken out from the movable die 3.

Next, the stamper 4 taken out is placed face down on a flat surface, and the back surface of the stamper 4 is flat-polished by using a commercially available metal-based abrasive, ceramic-based abrasive, abrasive cloth, or the like. I do. Basically, polishing should be done until the unevenness is eliminated, and further polishing should be avoided as much as possible because the stamper thickness is inadvertently thinned.

Next, on the back surface of the stamper after polishing, a plating film is formed by electrolytic plating or the like, for example, when the stamper 4 is made of nickel or an alloy thereof, a plating film M of the same or similar metals. The initial thickness of the stamper 4 is taken into consideration for the thickness of the plating film M so that the difference between the stamper thickness after plating and the initial thickness is minimized.

After reproduction, the stamper 4 is arranged again on the mirror surface 3a of the movable die 3, and the inner and outer peripheral edges of the stamper 4 are arranged on the inner ring 5.
It is held and used by the outer ring 6. Even when the back surface of the stamper 4 is uneven again due to the disk molding, one stamper 4 can be repeatedly used by reproducing it in the same procedure as above.

FIG. 2 shows a second reproducing method. First, the inner and outer rings 5, 6 are removed, and the stamper 4 having the unevenness 4a on the back surface is taken out from the movable die 3.

Next, on the uneven surface of the stamper 4 taken out,
If the plated film, for example, the stamper 4 is made of nickel or an alloy thereof by electrolytic plating or the like, the plated film M of the same or similar metal is formed. Basically, the thickness of the plating film M should be such that the irregularities are concealed, and if the plating film M is thicker than that, the thickness of the stamper is only carelessly increased, so avoiding it as much as possible.

Next, the stamper 4 after plating is placed on a flat surface with the plated surface facing upward, and the plated surface is coated with a commercially available metal-based abrasive, ceramic-based abrasive, or abrasive cloth paper. The surface is polished. In this polishing, the initial thickness of the stamper 4 is taken into consideration so that the difference between the stamper thickness after plating and the initial thickness is minimized.

After reproduction, the stamper 4 is again arranged on the mirror surface 3a of the movable die 3, and the inner and outer peripheral edges of the stamper 4 are arranged on the inner ring 5.
It is held and used by the outer ring 6. Even when the back surface of the stamper 4 is uneven again due to the disk molding, one stamper 4 can be repeatedly used by reproducing it in the same procedure as above.

In the embodiment, the stamper 4 is provided on the movable die 3 side, but the same reproducing method as above can be applied even when the stamper 4 is provided on the fixed die 1 side. Further, when the thickness of one plating process becomes insufficient, the plating process may be repeated a plurality of times.

[0021]

As described in detail above, according to the present invention,
By simply polishing and plating the surface of the stamper that contacts the mold, the same surface can be smoothed to supplement the stamper thickness and strength, which allows reuse of the stamper and the cost burden of stamper replacement. Can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a first reproduction method.

FIG. 2 is a diagram showing a second reproducing method.

FIG. 3 is a sectional view of an essential part of a disk molding die.

FIG. 4 is an explanatory diagram of a conventional problem

[Explanation of symbols]

1 ... Fixed type, 3 ... Movable type, 4 ... Stamper, 4a ... Roughness,
M ... Plating film.

Claims (2)

[Claims] 1. A method for remanufacturing a stamper used for molding a disc, comprising polishing a surface of the stamper on a side in contact with the mold to smooth the surface, and then forming a plating film on the same surface. Reproduction method of stamper for disk molding. 2. A method for remanufacturing a stamper used for molding a disc, comprising forming a plating film on the surface of the stamper that is in contact with the mold, and polishing the surface of the plating film to smooth the surface. And a method for reproducing a stamper for molding a disc.