JPH07241856A - Method of manufacturing electroformed duplicate stamper - Google Patents

Abstract

(57) [Summary] [Object] The present invention can obtain an electroformed duplication stamper having a uniform film thickness and can obtain a film thickness accuracy comparable to that of a conventional record disk, excluding the conventional drawbacks. Moreover, it is an object of the present invention to provide a method for manufacturing an electroformed duplication stamper that can manufacture a large stamper that cannot be handled by the conventional method. [Structure] First, the electrode mold (10) is kept in a flat plate shape in the electrodeposition tank (1
2) Electrodeposit it, take it out of the bath and release it from the electroform (10) to form a shell (13). With the surface (15) of the shell facing inward, apply silicone rubber or rubber. While winding around the coated cylinder roll (19) and fixing it, rotating the cylinder roll (19) together,
Further, it is a method for producing an electroformed duplication stamper in which the back surface of the shell is electrodeposited to obtain a uniform current density and an accurate film thickness.

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 an electroformed duplication stamper used as a precision stamper for producing optical products such as fly-eye lenses, lenticular lenses and Fresnel lenses.

[0002]

2. Description of the Related Art Conventionally, as a method of manufacturing a Fresnel lens or a fly's eye lens (22), as shown in FIG. 2 (a), a stamper (21) having a lens mold formed on the surface by cutting a metal plate with a lathe or the like. ) Is prepared and directly pressed onto a resin sheet by using this stamper, and the Fresnel lens (22)
The method of forming the like is general. However, it takes a long time to cut the metal plate to be the stamper (21), and if a defect occurs even once during the cutting process, there is a problem that the whole cannot be used. Then, as shown in FIG. 2B, the lens mold is once press-transferred from the stamper (21) to the resin plate to produce an electroformed stamper (23), and the electroformed stamper (24) is formed from the electroformed stamper. Since multiple Fresnel lenses (22) are manufactured by making a plurality of sheets of the electroformed stamper on a resin sheet using this electroformed stamper, the original metal plate stamper (21) should be used for a long period of time. You can

Further, conventionally, for a relatively small stamper having a diameter of about 30 cm, such as a record board or a CD, a duplication method by electroforming is generally used. Further, as a method for mass-producing flat plate for practical printing plate, electrodeposition (metal plating) is applied to the surface of the cylinder, a stamper mold is formed on this surface by etching or cutting, and then this electrodeposition is performed. A method for producing a practical plate is known in which layers are peeled off to form a shell, and the shell is flatly spread.

However, in the above method, it is necessary to directly process the cylinder roll. For example, when forming a groove or hole in one direction like a lenticular lens, it is relatively easy to place a bite in the rotation direction of the cylinder roll and cut while rotating the cylinder roll,
It can perform accurate processing, but when it is necessary to perform cutting in a direction other than the rotation direction of the cylinder roll such as Fresnel lens or fly eye lens,
There was a problem that it could not be processed accurately.
In particular, when processing a Fresnel lens on the surface of a cylinder roll, it is necessary to calculate in advance so that a circular groove will be carved when it is developed on a flat surface, but this method is very difficult. Has not been produced.

Further, in the electroforming method used for a record board or the like, unlike the practical plate for printing, the electrodeposited surface is not cut, but first, the original plate is cut. It is a duplicate of the shape. In the process, a thin conductive film is formed on the surface of the original plate, a metal layer is electrodeposited on the conductive film by the principle of electroplating, and an electroformed stamper is obtained from this metal layer having a predetermined thickness. According to the electroforming method, the stamper can be accurately formed from the original plate.

Further, as a method adopted when mass-producing flat plates by electroforming, there is known a method of electrodepositing while rotating the electrode (34) as shown in FIG. 3 (c). ing. Compared with the method shown in FIG. 3A, this has the advantage that the difference in film thickness is small because the variation in current density is small, and the plating effect is not caused even at high current density because the stirring effect is large. On the other hand, the disadvantage is that turning a large object with high precision requires large-scale equipment and is not practical. Therefore, a large plate-shaped stamper cannot be produced by the conventional method for producing a stamper for a record board.

Further, as shown in FIG. 3 (a), a conventional electrodeposition method in which a flat plate-shaped electric mold (32) is swung by a cathode rocker (33) suspended in an electrodeposition tank (plating bath) is also used. However, as described above, it is difficult to control the current density, and the peripheral portion is thick and the central portion is thin in many cases. Therefore, a polishing process for the obtained shell is required, but if this is also larger than a stamper such as a record, it becomes difficult to polish it with high precision.

[0008]

Therefore, the present invention can obtain an electroformed duplication stamper having a uniform film thickness and can obtain an accuracy of the film thickness comparable to the duplication of a conventional record board, except for the drawbacks of the prior art. It is an object of the present invention to provide a method for manufacturing an electroformed duplication stamper that can manufacture a large stamper that cannot be handled by the conventional method.

[0009]

In order to achieve the above object, according to the method of manufacturing an electroformed duplication stamper according to the present invention, the electroform (10) is first kept in a flat plate shape in the electrodeposition tank (1).
2) Electrodeposit it, take it out of the bath and release it from the electroform (10) to form a shell (13). With the surface (15) of the shell facing inward, apply silicone rubber or rubber. While winding around the coated cylinder roll (19) and fixing it, rotating the cylinder roll (19) together,
Further, by electrodepositing the back surface of the shell, the current density is made uniform to obtain an accurate film thickness.

The present invention will be described in detail below with reference to the drawings. FIG. 1 is an explanatory view of a method for manufacturing an electroformed duplicate stamper according to the present invention.

First, an electroforming type (10) for electroforming as shown in FIG. 1 (a) is manufactured by a pressing method or the like. This has the reverse shape of the metal original plate formed by cutting etc.,
The material is a thermoplastic resin such as polymethylmethacrylate, polystyrene, polyvinyl chloride or polycarbonate, a thermosetting resin such as an epoxy resin, a pomide resin, a polyamide resin or nylon, or a copolymer such as an MS resin or an ABS resin. Polymethylmethacrylate, polystyrene,
Thermoplastic resins such as polyvinyl chloride and polycarbonate are suitable for production by the pressing method.

Next, as shown in FIG.
A conductive film (11) is formed on the surface of (0). This conductive film (11) may be a wet method such as a silver mirror method or electroless plating, or a dry method such as vapor deposition, sputtering, or thermal spraying, and the kind of metal may be gold, silver, nickel, chromium, or an alloy containing them. desirable.

Then, as shown in FIG. 1 (c), it is placed in an electrodeposition tank (12) for electrodeposition. The film thickness of electrodeposition here is
The smaller the thickness, the smaller the variation in the film thickness. Therefore, at least the strength is required so that the shape is not damaged when peeled from the electric mold after this. In this case, 50
A film thickness of μm to 300 μm, preferably 70 μm to 150 μm is required.

After electrodeposition, as shown in FIG. 1D, the shell (13) is formed by removing the electrode mold (10) from the electrodeposition tank and peeling it off. . Then, the shell (13) obtained as shown in FIG. 1 (e) is wound around a silicone rubber or a rubber-coated cylinder roll (19). The winding shell (13) is oriented so that the surface (15) (the surface on which the shape is transferred) is inward. This cylinder roll may be made of iron or copper for ordinary printing plate plating, but a roll whose surface is preferably coated with silicone rubber or viton rubber does not impair the surface shape of the shell. However, it is necessary that the length of one round of the cylinder roll (19) is larger than the length of the shell (13).

In the case of a conductive cylinder roll (19), the plating solution is sealed so as not to enter the inside of the shell (13), and in the case of a non-conductive roll, it is conducted to the shell (13). Then, as shown in FIG. 1 (f), the cylinder roll (19) is placed in the electrodeposition tank (12) again, and the cylinder roll is rotated to perform electrodeposition on the back surface (16) of the shell. The electrodeposition here needs to have an appropriate thickness in order to obtain sufficient strength as a stamper and to be used as a flat plate stamper after peeling from the cylinder roll, and preferably about 200 μm to 700 μm.

After completion of electrodeposition, the cylinder roll is taken out of the electrodeposition tank and peeled off to obtain an electroformed duplicate stamper. Here, if desired, the back surface (16) can be subjected to the polishing step while the electroformed duplication stamper is fixed to the cylinder roll. Polishing is preferably buffing, which is performed while rotating a cylinder, which is usually performed in a printing process. Then, as shown in FIG. 1 (h), a flat electroformed duplication stamper is obtained.

[0017]

According to the present invention, the current density unevenness occurs in the case of plate-shaped electrodeposition up to now, but the unevenness disappears when the electrodeposition is performed while being wound around a cylinder roll and rotated, so that a uniform current can be obtained. As a result, the uniform film thickness can be obtained. Further, since polishing can be performed while being set on the cylinder roll, polishing can be performed more easily than that of a flat plate type, so that an electroformed duplication stamper having a uniform film thickness and no pits or protrusions can be obtained. it can.

【Example】

Specific examples of the present invention will be described below.

<Example 1> A Fresnel lens shape was cut on a brass plate according to a conventional method, and a black acrylic plate (acrylic light L, manufactured by Mitsubishi Rayon Co., Ltd.) was formed into a shape by a pressing method using this original plate. Transferred to obtain an electric type (10). This electrotype (10) is washed with a commercially available neutral detergent and pure water, and a conductive film (11) is applied to the surface by silver mirror reaction. After that, electrical continuity is established through a jig, and an electrodeposition tank (1) for a plating bath containing nickel sulfamate as a main component, which is usually used for electrodeposition,
Put in 2). The current density was about 1 A / dm ² , and electrodeposition was performed so that the average film thickness was 100 μm.

After electrodeposition, it is taken out from the electrodeposition tank, washed, and peeled from the electrode mold (10) to form a shell (13). With the surface of this shell (13) inside, wrap it around a cylinder roll (19) coated with silicone rubber,
Fix with a jig to make it conductive. This cylinder roll is placed in a copper electrodeposition bath (copper plating bath), and while the cylinder roll is being rotated, the current density is about 10 A / dm ² , and the shell (13) backside is electrodeposited so that the average film thickness is 500 μm. gave. After electroforming, cleaning and polishing were performed using a normal cylinder roll polishing apparatus to obtain an electroformed duplicate stamper.

Example 2 A shell (13) was obtained by the same steps as in Example 1. The shell (13) was wound around a silicone rubber cylinder roll (19) with the surface inside, and fixed with a jig and brought into conduction. This cylinder roll was again placed in an electrodeposition bath of a plating bath containing nickel sulfamate as a main component, and while the cylinder roll was rotated, electrodeposition was performed at a current density of about 10 A / dm ² and an average film thickness of 400 μm. did. After electrodeposition, it was washed and polished by a normal cylinder roll polishing apparatus to obtain an electroformed duplicate stamper.

[0022]

INDUSTRIAL APPLICABILITY As described above, according to the present invention, the uneven current density, which has been generated by plate-shaped electrodeposition up to now, can be uniformly wound on a cylinder roll by rotating it. Since it can be made to flow and can be polished on the cylinder, the polishing process is easier than the conventional flat plate polishing, and an electroformed duplicate with a uniform film thickness and no pits or protrusions can be obtained. . In addition, since the electrodeposition can be performed while rotating the cylinder roll, the stirring effect is increased, and the electrodeposition can be performed at a high current density like the rotating electrode method used for the stamper of the record board. It was shortened. Further, by performing the electrodeposition with this high current density, the crystals of the deposited metal are made finer, and various excellent effects of improving the quality of plating are produced.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a manufacturing process of an electroformed duplication stamper according to the present invention.

FIG. 2 is an explanatory diagram of an electroforming method.

FIG. 3 is an explanatory diagram of a method of manufacturing a lens sheet.

[Explanation of symbols]

10, 23 ... Electric type 11 ... Conductive film 12 ... Electrodeposition bath (plating bath) 13 ... Shell 15 ... Shell front surface 16 ... Shell back surface 19 ... Silicon rubber or rubber-coated cylinder roll 21 ... Original plate 22 ... Fresnel Lens 24 ... Duplicating stamper 32 ... Electrotype 33 ... Cathode rocker 34 ... Electrode

Claims (3)

[Claims] 1. A method for producing a flat plate electroformed duplication stamper, which is produced by electroforming from an original plate, electrodepositing copper, nickel or the like to a desired thickness to form a shell, and processing the shell. After performing a conductive treatment and a mold release treatment on the surface of a flat plate-shaped electrotype, the surface of the shell is made to be an inner side by duplicating a thin plate-shaped shell by performing electrodeposition on this surface and peeling it from the electrotype. It is wound around a cylinder roll coated with silicone rubber or rubber, and while the cylinder roll is rotated, the back surface of the shell is further electrodeposited, and the back surface of the shell is polished and then flattened into a flat plate. Stamper manufacturing method. 2. A method for producing a flat plate electroformed duplication stamper, which comprises electroforming from an original plate, electrodepositing copper, nickel or the like to a desired thickness to form a shell, and processing the shell. After conducting a conductive treatment and a mold release treatment on the surface of the plate-shaped electric mold, the surface is subjected to electrodeposition to a thickness of 50 to 300 μm, particularly preferably 70 to 150 μm, and this is taken out from the electric mold. A thin plate-shaped shell is duplicated by molding and wound around a cylinder roll coated with silicon rubber or rubber with the surface of the shell inside, and while the cylinder roll is rotated, 200 to 700
A method of manufacturing an electroformed duplication stamper, which comprises subjecting the back surface of the shell to electroplating of μm and polishing the back surface of the shell to form a flat plate. 3. The first electrodeposition is a nickel plating bath containing nickel sulfamate as a main component, and the electrodeposition performed by winding around a cylinder roll is a nickel plating bath containing nickel sulfamate as a main component or copper sulfate. The method for producing an electroformed replication stamper according to claim 1 or 2, wherein the copper plating bath is a main component.