JPH06195761A - Manufacture for nickel stamper and manufacturing apparatus therefor - Google Patents

Abstract

PURPOSE:To obtain a manufacture and a manufacturing apparatus of a highly reliable stamper whereby the thickness of the nickel stamper is made uniform and a polishing process of the rear face is eliminated. CONSTITUTION:The manufacturing apparatus of a nickel stamper is constituted of an electrode basket 4 accommodating a nickel material for feeding nickel ions, an electrode 2 for fixing a disc original, a motor 3 for rotating the electrode 2, an electrode brush 5 for supplying a current to the electrode 2, a power source 7 for feeding the current, and a switch 8 for switching the running direction of the current. In order to obtain the nickel stamper, a plating current is repeatedly turned into a conductive state and a conduction stopping state until the nickel is formed 300mum thick or so. Thereafter, the running direction of the plating current is changed by the switch 8, and the electrolytic polishing and removing of the projections and recesses on the surface of the nickel are executed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing an optical disk stamper used as a master for copying an optical disk.

[0002]

2. Description of the Related Art A conventional stamper manufacturing method is disclosed in JP-B-60.
-28048, "Method for manufacturing master stamper"
It will be explained using a part of the contents described in. Figure 3
FIG. 4 is a manufacturing process diagram of a nickel stamper, and FIG. 4 is a diagram showing a relationship between a plating time and a plating current during electroplating.

First, the glass master disk 20 is thoroughly cleaned in a cleaning process, and a resist layer 21 having a thickness of about 1000 Å is formed in a resist coating process.

Next, the unevenness which becomes a signal in the exposure step, or the place where the track groove is to be formed is exposed with a laser beam,
Development is performed in the developing process to form uneven signals or track grooves.

Next, in the step of forming the metal layer 1, the metal layer 2 having a thickness of about 600 Å is formed on the surface of the resist layer 21 on which irregularities or grooves are formed by a method such as vacuum deposition and sputtering.
Form 2.

Further, nickel electroplating is performed in the metal layer forming step 2 to form a metal layer 23 made of nickel and having a thickness of 300 μm. At this time, the initial cathode current flowing through the glass master 20 on the cathode side is a low current I1 for about T1 hours to prevent the metal layer 22 from being destroyed by the cathode current, and then a high current I2 is passed for T2 hours. Next, the unevenness generated on the back surface is polished with an emery paper or the like to make it smooth, and finally, the resist layer 21, the metal layers 22 and 23 are peeled from the glass master 20 in the peeling step, and the layers peeled in the resist cleaning step are The resist layer 21 adhering to the surface is washed off with a resist solution to manufacture a master stamper.

[0007]

However, the above manufacturing process has the following problems.

The first problem is that when nickel is formed on the surface of the glass master by electroplating, the variation in nickel film thickness between the central portion and the outer peripheral portion of the glass master is 50 to 1.
It is about 00 μm, and tends to be thickly formed on the outer peripheral portion. This is a phenomenon that occurs when the cathode current is continuously applied because the nickel ion concentration on the surface of the glass master disc differs between the central portion and the outer peripheral portion.Therefore, the actual nickel stamper is larger than the desired shape. After manufacturing, the thick outer peripheral part is cut with a mold to manufacture a nickel stamper. In the step of cutting with this mold, it was difficult to eliminate burrs on the cut surface, warpage of the nickel stamper, and the like.

The second problem is that since the back surface is polished with emery paper or the like, the number of steps is increased, and the nickel stamper is easily warped or the signal surface is easily scratched. Nickel stamper warpage and scratches on the signal surface cause resin flow and uneven thickness of the replica when the stamper is mounted on a resin molding machine and injection-molded to produce a replica, resulting in poor signal quality during signal reproduction. Had an influence.

Therefore, according to the present invention, a step of cutting with a die by making the thickness of the nickel stamper uniform in the plating step,
Moreover, it is an object of the present invention to provide a highly reliable stamper manufacturing method and a manufacturing apparatus therefor, in which the step of polishing the back surface is reduced.

[0011]

The present invention for solving the above-mentioned problems is a method for producing a nickel stamper by electroplating from a disk master having an uneven signal or groove, which comprises nickel sulfamate, The electrode basket containing the nickel material that supplies nickel ions in the electrolyte containing nickel chloride and boric acid as the anode is the anode, and the disk master is the cathode, and the plating current is intermittently applied to form nickel. After forming nickel of about 300 μm on the surface of the master, the nickel surface is electropolished by reversing the polarities of the electrode basket and the master of the disk.

Further, in a manufacturing apparatus for manufacturing a nickel stamper by electroplating from a disk master having an uneven signal or groove, a rotating mechanism for rotating the disk master, an electrode basket containing nickel material, and a power supply for supplying an electric current. , Has a configuration including a switching device that switches the direction of current flow.

[0013]

As described above, according to the present invention, the nickel ion concentration in the vicinity of the surface of the glass master disk can be always kept uniform by intermittently supplying the cathode current to the master disk, so that the nickel thickness can be made uniform. can do.
In addition, after forming to a desired thickness, by applying a plating current in the direction opposite to that at the time of formation, electrolytic polishing of the irregularities on the back surface does not require polishing with conventional emery paper, etc. No scratches on the surface.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings. FIG. 1 is a configuration diagram of a plating apparatus showing an embodiment of the present invention, and FIG. 2 is a diagram showing a relationship between a cathode current and a plating time, and an anode current and a polishing time. 1, the plating apparatus of the present invention includes an electrode basket 4 containing a nickel material for supplying nickel ions, an electrode 2 for fixing a glass master 1 as a rotating mechanism, and a motor 3 for rotating the electrode 2. , An electrode brush 5 for supplying a current to the electrode 2, a power supply 7 for supplying a current, and a switch 8 for switching the direction in which the current flows.
It consists of

The electrolytic solution 6 in the bath 9 is composed of nickel sulfamate, nickel chloride, boric acid, and a pit preventive agent. A photoresist is applied to a disk-shaped glass plate, and uneven signals or track grooves are formed on the surface thereof. After forming, the glass master 1 on which a nickel metal layer of about 600 Å is formed by sputtering, vacuum deposition or the like is fixed to the electrode 2, and the electrode basket 4 is anodized while rotating in the electrolytic solution 6 at a rotation speed of 10 to 20 rpm. Then, a current is caused to flow using the glass master 1 as a cathode. At this time, the current flowing through the glass master 1 becomes a cathode current.

Next, the relationship between current and time will be described with reference to FIG. At the initial stage of plating, when a high cathode current I2 is applied because the nickel metal layer is thin, the contact between the electrode 2 and the nickel metal layer causes destruction of the metal layer. Gradually form to μm. After that, a high cathode current I2 is applied to form nickel, but the nickel ion concentration on the surface of the glass master 1 gradually differs between the central portion and the outer peripheral portion, and the thickness varies. At this time, by stopping energization for a certain period of time, the nickel ion concentration on the surface of the glass master 1 can be made uniform again. In this way, when the cathode current of plating is in the energized state and the energized state is not applied, the nickel thickness is 300 μm.
By repeating the process intermittently until the thickness reaches about m, the thickness of the central portion and the outer peripheral portion can be made uniform.

After nickel is formed to a thickness of about 300 μm, the direction of current flow is reversed by the switching device 8 of the plating apparatus. By switching the direction of the current flow, the electrode basket 4 changes from the anode to the cathode, and the polarity of the electrode 2 changes from the cathode to the anode. Therefore, the anode current I3 flows through the glass master 1 and nickel on the nickel surface is changed. Melting begins and the surface irregularities are removed. Finally, the stamper is peeled off from the glass master and the resist adhering to the peeled surface is washed off with a resist solution to complete the production of the master stamper.

In the embodiment of the present invention, the glass master is used as the master, but the same effect can be obtained by using a metal master such as gold, copper or aluminum.

[0019]

As described above, according to the method and apparatus for manufacturing a nickel stamper of the present invention, since the thickness of the nickel stamper can be made uniform, it is not necessary to form the shape by a conventional die. Becomes Further, since electrolytic polishing is performed in the plating apparatus, it is not necessary to polish the back surface with emery paper or the like, and an inexpensive and highly reliable nickel stamper can be manufactured.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of an apparatus for manufacturing a nickel stamper of the present invention.

FIG. 2 is a diagram showing the relationship between current and time during plating and polishing in the apparatus of the embodiment.

FIG. 3 is a manufacturing process diagram of a conventional nickel stamper.

FIG. 4 is a diagram showing the relationship between current and time during plating in the conventional manufacturing method.

[Explanation of symbols]

 1 Glass Master 2 Electrode 3 Motor 4 Electrode Basket 5 Electrode Brush 6 Electrolyte 7 Power Supply 8 Switcher 9 Bath 20 Glass Plate 21 Resist 22, 23 Metal Layer

Claims (4)

[Claims] 1. A method of manufacturing a nickel stamper by electroplating from a disk master having an uneven signal or groove, wherein nickel ions are contained in an electrolytic solution containing nickel sulfamate, nickel chloride and boric acid as main components. A method for producing a nickel stamper, characterized in that an electrode basket containing a nickel material to be supplied is used as an anode and a disk master is used as a cathode, and a cathode current is intermittently applied to form nickel. 2. A method for manufacturing a nickel stamper by electroplating from a disk master having an uneven signal or groove formed therein, wherein nickel ions are contained in an electrolytic solution containing nickel sulfamate, nickel chloride and boric acid as main components. The nickel material to be supplied and the electrode basket containing it are used as the anode, and the disk master is used as the cathode.
A method for manufacturing a nickel stamper, which comprises electrolytically polishing the nickel surface by reversing the polarities of the electrode basket and the disk master after forming nickel of about 00 μm. 3. The method for manufacturing a nickel stamper according to claim 2, wherein the electric current during electrolytic polishing is smaller than the electric current during formation. 4. A manufacturing apparatus for manufacturing a nickel stamper from a disk master having an uneven signal or groove formed by electroplating, which comprises a rotating mechanism for rotating the disk master, an electrode basket containing nickel material, and an electric current supply. An apparatus for manufacturing a nickel stamper, comprising a switching device that switches a power source and a current flowing direction.