JPH0215927B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for manufacturing a replica disk.

A general method for manufacturing a duplicate disc from a master disc containing video and/or audio information is, as shown in FIG. Based on the signal light obtained, it is shaped so that it exhibits a change according to the information (Fig. 1A), and then
Nickel 3 is electroformed on the molded photoresist layer 2 (Figure 1B), and a Nickel master (No. 1
Figure C) is manufactured, and a duplicate disk 5 is manufactured based on this master 4. This duplicate disk 5 is then subjected to a post-processing process in which an aluminum evaporated film 6 is formed on its surface (FIG. 1D), and a transparent protective film 7 is further formed above it (FIG. 1D). e). Incidentally, as a method for manufacturing the duplicate disk 5 from the master 4, an in-die extraction method has conventionally been used, but as another method, a method using an ultraviolet curing resin has been proposed in Japanese Patent Laid-Open No. 138406/1983. ing. The outline is that a liquid ultraviolet curing resin is applied to the surface of a nickel master, a transparent plate is placed above this coating layer, and ultraviolet rays are irradiated from above the transparent plate to cure the resin. Thereafter, the cured resin is separated from the master. Here, if you select a UV curing resin that does not adhere to metal (nickel) after curing but has strong adhesion strength to transparent plates (resin such as acrylic), the cured resin on the master A duplicate disk can be manufactured by peeling off the disk together with a transparent plate. In all of the conventional examples described above, the master is manufactured once, so a master manufacturing process is required.

In order to easily manufacture a duplicate disk, the present invention has the following advantages:
This master manufacturing process is intended to be omitted. Next, one embodiment of the present invention will be described with reference to the process diagram shown in FIG.

In the method for manufacturing a duplicate disk of the present invention, the base 10
The first step is to form the photoresist layer 11 coated on the surface of the formed photoresist layer so as to exhibit a shape change 12 according to the information based on the signal light modulated by the information (Fig. 2A), and Metal film 14 having shape change 13 commensurate with shape change 12
(FIG. 2 b) The second step of forming the metal film 14
A third step of applying a radiation-curable liquid lacquer 15 on top of the lacquer (FIG. 2C), and disposing a transparent plate 16 made of, for example, acrylic resin on the top surface of this lacquer (FIG. 2D); Radiation is irradiated from above 16 to harden the liquid lacquer 13 (not shown)
and a fifth step of separating the hardened lacquer layer 17 from the metal film 13 (FIG. 2(e)), and the duplicate disk 18 manufactured in this way is subjected to post-treatment similar to the conventional example, i.e. A light-reflecting aluminum evaporated film 19 is formed on the upper surface of the hardened lacquer layer 17, and a protective transparent film 20 is further formed above it to produce a replica disk as shown in FIG. 2F.

The first step is a conventionally well-known photoresist method,
It is recognized that supplementary explanation is not necessary. The metal film in the second step is a metal that has excellent adhesion to the photoresist and low adhesion to the ultraviolet curable resin and is easily deposited (silver, copper, aluminum, silica, bismuth, tin, etc.). As a result of experimental evaluation mainly regarding peeling properties, it was found that silver, copper, and aluminum were excellent in that order (some samples did not have the desired properties with aluminum), and other materials were found to be unsuitable. Here, the peeling property is an evaluation of whether the metal film or photoresist adheres to the duplicate disk separated in the fifth step. Metal film 14
Figure 3 shows the detection signal ratio (%) characteristics of the VLP system signal with respect to its thickness (angstroms (Å)), and from this result, it is clear that attenuation will occur unless the thickness is 2000 Å or less. Turns out it's too big. On the other hand, another experiment showed that
It has been found that the adhesion strength to the molded photoresist layer 11 is sufficient when the metal film 14 has a thickness of 1500 to 2500 (Å). Therefore, the metal film 14 is a silver or copper film, and a film thickness of 1500 to 2000 (Å) is suitable. As the liquid lacquer 15 used in the third step, for example, resin material number 35768 manufactured by Loctite Co., Ltd. can be used. or,
In carrying out the fourth step and the fifth step, the technology described in the above-mentioned publication may be used.

As described above, in the method of the present invention, a metal film having a shape change commensurate with the shape change of the photoresist is formed on the formed photoresist layer, and the liquid lacquer provided thereon is solidified, so that it is possible to A duplicate disc can be obtained directly, the master disk manufacturing process can be omitted, and the duplicate disc can be manufactured at a low cost.

[Brief explanation of drawings]

Fig. 1 A to H are process diagrams of a conventional general method for manufacturing a replica disk, and Fig. 2 A to F are process diagrams of the method of the present invention.
It is a process diagram of an example. FIG. 3 shows the metal film thickness versus detection output ratio characteristics. Explanation of main drawing numbers, 10...base, 11...photoresist layer, 13...metal film, 15...liquid lacquer, 17...hardened lacquer, 16...transparent plate.

Claims (1)

[Scope of Claims] 1. A step of forming a photoresist layer applied on the surface of the base so as to exhibit a shape change according to information based on signal light modulated by information, and forming the photoresist layer on the formed photoresist layer. forming a metal film having a shape change commensurate with the shape change; applying a radiation-curable liquid lacquer on the metal film;
Furthermore, a step of disposing a transparent plate on the upper surface of the lacquer, a step of curing the liquid lacquer by irradiating radiation from above the transparent plate, a step of separating the hardened lacquer layer from the metal film, and a step of separating the cured lacquer layer from the metal film are performed. A method for manufacturing a replica disk comprising the steps of forming a vapor deposited film for light reflection on a separated surface of the layers, and further forming a protective film on the vapor deposited film. 2. The method for manufacturing a duplicate disk according to claim 1, wherein the metal film is made of silver or copper. 3. The method for manufacturing a replica disk according to claim 1 or 2, wherein the metal film has a thickness of 1500 to 2000 angstroms.