JPS61221392A - Stamper - Google Patents

Abstract

PURPOSE:To provide a stamper which has excellent durability in the stage of reproduction and permits easy working by forming the 1st electroforming Ni film having a specific thickness on a substrate by using an insoluble electrode then forming the 2nd electroforming Ni film having a prescribed thickness thereon by using a soluble electrode. CONSTITUTION:The electroforming Ni film is formed on the master disk having a fine pattern by using the insoluble electrode in an Ni bath and is stripped to form a mother stamper. The surface of the mother stamper is subjected to a treatment for accelerating stripping and thereafter the 1st electroforming Ni film is formed thereon to 1-10mum thickness by an electroforming device for which the insoluble electrode is used. The 2nd electroforming Ni film is then formed thereon to about 250mum thickness by an electroforming device for which the soluble electrode made of granular Ni is used. The film is stripped from the mother stamper and a stamper for forming an optical disk, etc. is obtd. The durability of the stamper is improved and the drawing property is improved by the formation of two layers of the Ni films.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a stamper used when producing a copy of a master by transferring a fine pattern recorded on the master.

[Technical background of the invention and its problems]

It is well known that a thin disc-shaped metal plate called a stamper is used in the manufacturing process of, for example, record discs. Such a stamper is made by the following process.

First, a master disc is created by carving a pattern in the form of grooves on a car board using a needle. Next, a conductive layer is provided on this master by silver mirror reaction or the like, and then nickel plating is applied to a thickness of 200 to 300 μm to form a peeled nickel at master stamper. Although it is possible to make copies using this master stamper, only one copy of this master stamper can be taken from the master, which limits the number of copies that can be made in one climat. Therefore, peeling usually begins on this master surface f!
! ! Then, a plurality of mother stampers made of the peeled nickel film were prepared, and the surface of the mother stamper was subjected to peeling treatment, and then nickel plating was applied to the nickel film thus obtained. was used as a stamper to make a copy.

On the other hand, for the purpose of increasing the recording density, master discs are known in which fine patterns are engraved by optically etching a photosensitive resin film coated on a glass plate, for example. A stamper can also be obtained from this master in the same manner as described above.

The stamper thus obtained was used as a mold to produce a replica in which the fine pattern recorded on the master was transferred onto the surface by injection molding, compression molding, or John molding.

In the conventional manufacturing process of stampers using electroforming, a molten electrode was used as an anode during electroforming, so the surface hardness of the resulting stamper was as low as about 20 QHv, and high durability was expected. However, only a small number of copies were made.

For this reason, for example, in stampers used for copying records, the surface hardness has been increased by applying chromium plating to the surface, but this method also applies when the signal pattern is fine, such as on optical discs. In such cases, there is a problem in that the pattern is damaged by the chromium plating applied to the surface of the stamper.

In addition, in response to these issues,
No. 6, No. 2003-11-103, discloses that the surface hardness of the cis-stamper can be made approximately 500 Hv by plating the anode using an insoluble anode. However, the stamper formed by this method is difficult to form when used by drawing, etc., which is performed during the production of copies, and a new problem arises in that the stamper is prone to cracking during stamping. Occurred.

[Purpose of the invention]

An object of the present invention is to provide a stamper that has excellent durability during duplication and is easy to shape.

[Summary of the invention]

The stamper according to the present invention first has a first stamper having a thickness of 1 μm or more and less than 10 μm on a master formed using an insoluble anode in a nickel bath. It is characterized by having a cast nickel film and a second electroformed nickel film formed on the first electroformed nickel film using a molten anode in a nickel melt.

FIG. 1 shows a schematic cross-sectional view of an example of a stamper according to the present invention. In the figure, 1 is a first electroformed nickel film formed using an insoluble anode, and 2 is a second electroformed nickel film formed using a molten anode. Further, 3 is a fine pattern formed on the surface of the stamper. As described above, the stamper according to the present invention has films each having different characteristics, and the synergistic effect of these two layers of films provides a stamper with durability and workability.

Examples of insoluble anodes used here include a nickel plate coated with gold or platinum, and a titanium plate coated with gold or platinum. Examples of the melted anode include granular nickel or plate-shaped nickel. Further, as the nickel solution, it is desirable to select a nickel sulfamate solution that can deposit a film with low stress.

In addition, in the present invention, the first
The reason why the thickness of the electroformed nickel film was defined as 1 μm or more and less than 10 μm is as follows. That is, as shown in the characteristic diagram of Fig. 2, which shows the relationship between the thickness of the first electroformed nickel film and the stamper life (the number of times it can be replicated), which is an index of the durability of the stamper, This is because if the thickness of the electroformed nickel film is less than 1 μm, the surface hardness will be low and the effect of improving the durability of the stamper will not be sufficiently achieved.

This is because when the thickness of the first electroformed nickel film is 10 μm or more, drawing workability becomes a problem.

EXAMPLES The present invention will be explained in more detail with reference to Examples below.

[Embodiments of the invention]

A 300A to 600A silver layer is formed on the master disk using a vacuum polishing device to form a conductive layer on the patterned surface of the master disk. gave gender. Next, an insoluble anode consisting of a titanium plate coated with platinum was used as an anode. This master disk was attached to the rotating cathode of a casting device so that the pattern surface t-11 was the exit surface. This master was placed in a nickel bath for about 10 minutes.
While rotating with the ORP M, an electroformed nickel film is formed to a thickness of about 250 μm, and then peeled off from the master, and the electroformed nickel film with silver attached to the surface is used as a mask/stambar for forming optical discs. Obtained.

Next, the surface of this mask/stambar was treated with a potassium dichromate solution (5 wt%) to promote peeling, and then an electroformed nickel film was formed on the surface in the same manner as above, and then it was peeled off from the mask/stambar. Formed a mother stanbar.

Next, the surface of the mother stanbar was treated with a potassium dichromate solution (5 wt%) to promote peeling, and then the same process as described above was performed using an electroforming machine using an insoluble anode to form the first layer to a thickness of approximately 5 μm. An electroformed nickel film was formed.

Next, a second cast nickel film was formed to a thickness of about 250 μm in a casting device using a molten anode made of granular nickel,
Peel it off from the mother stanbar to obtain a stanbar for forming an optical disc.

The nickel solution used here was nickel sulfamate 6
001/11, boric acid 40P/λ and bit inhibitor Nystar 806 (manufactured by Uezai Kogyo ■: trade name) 1m1. /
It is composed of.

Using this stanbar, we made a replica by injection molding acrylic resin (using 5-35 manufactured by Mitsubishi Rayon ■), and deposited aluminum as a reflective film on the fine pattern transfer surface to create an optical video. The table shows the surface hardness, stambar life, and drawability of the stambar at the time the disk was manufactured. In addition, as Comparative Example 1, a mother stanbar prepared in the same manner as in the example was treated with a weight of potassium oA acid to promote peeling, and a dissolving anode was used. After casting, only the second electroformed nickel film was formed to a thickness of about 250 μm, and then peeled off from the mother stanbar to obtain a stanbar. Furthermore, as Comparative Example 2, a stand bar made of only the first electroformed nickel film was similarly evaluated using an electroforming apparatus using an insoluble anode instead of the molten anode of Comparative Example 1, and the results are shown in the following table.

This table shows that the surface hardness of the Example is increased by about 3 times compared to Comparative Example 1, and therefore the stand-bar life is also increased by more than 3 times. It can also be seen that the drawability is improved compared to Comparative Example 2.

〔Effect of the invention〕

As described above, the stambar of the present invention has two different electroformed layers, the first and second layers.

By having the Kel film, the durability of the stambar can be improved and the drawability can be improved.

[Brief Description of the Drawings] Figure 1 is a schematic cross-sectional view of the stubber of the present invention. Figure 2 is a characteristic showing the relationship between the thickness of the first t@nickel film and the stubber life of the stubber of the present invention. It is a diagram. 1... First electroformed nickel film formed using an insoluble anode 2... Second electroformed nickel film 3 formed using a molten anode... Fine pattern

Claims (1)

[Claims] In a stamper used to transfer a fine pattern recorded on a master to produce a copy, the first stamper is formed to have a thickness of 1 μm or more and less than 10 μm using an insoluble anode in nickel melt. A stamper comprising: an electroformed nickel film; and a second electroformed nickel film formed on the first electroformed nickel film using a melting anode.