JPH03291392A - Method for electroforming electroformed master disk and electroformed master disk - Google Patents

Abstract

PURPOSE:To produce an electroformed master disk as an Ni master disk in a flaw-free state by attaching a conductive ring for electroforming to the outside periphery of an electroformed recording master disk and electrifying the recording surface of the recording master disk via the ring in an Ni plating bath at the time of producing an electroformed master disk to which an information recording master disk is transferred. CONSTITUTION:After an information 13 is cut by means of laser beam in a photoresist 4 applied to a glass plate 6 and a conductive film 5 is formed on the above by means of silver mirror reaction to form a photoresist master disk 10, Ni is electroformed to form an Ni master disk 1. A conductive ring 2 for electroforming having a diameter practically equal to that of the master disk 10 is placed on the outside periphery of the master disk 10, which is set in a member consisting of a cathode 8 and a presser part 7. The photoresist master disk 10 is immersed into an Ni plating bath and the conductive film 5 is electrified via a conductive plate 9 and the ring 2 to form an Ni electroformed layer 3, by which a pattern for the master disk 1 consisting of the electroformed layer 3 and the ring 2 is formed. Subsequently, the above pattern is taken out of the Ni plating bath and the surface of the Ni electroformed layer is polished, and then, the photoresist master disk 10 and the Ni electroformed layer 3 are peeled off, by which the Ni master disk 1 can he completed.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for manufacturing an optical disc in which information signals are recorded by optical changes that can be detected with light, and in particular to a method for producing an optical disc in which information is transferred from a recording master to an electroformed master plate. This invention relates to an electroforming method for producing.

[Conventional technology]

In recent years, optical disk media such as compact disks (CDs), laser disks (LDs), and magneto-optical disks, which record and reproduce information signals using optical spots, have been put into practical use. These are characterized in that they enable very high density recording, are fast to access, and do not wear out the signal surface.

This popular optical disc medium increases the dynamic range and records data by converting analog information signals into digital signals, making it resistant to noise. In general, conversion from analog signals to digital signals is performed by pulse code modulation (PCM), and the information signal modulated into the PCM signal is transmitted by a light spot to the recording film on the disk, such as uneven pits, presence or absence of a reflective film, etc. It is recorded by writing marks such as deformation, refractive index change, and magnetization reversal.

Conventionally, the manufacturing process for such optical discs involves forming a photoresist or metal layer, which is a recording material, to a predetermined thickness on a glass disc, and exposing and recording information (bit strings) with a laser beam spot to create a recording master disc. Create. Then, the recording master disk is subjected to nickel electroforming to obtain a nickel master disk on which pit rows are transferred from the surface of the recording master disk. Then, the nickel master disk that has been treated with a peeling film is electroformed under the same plating conditions and peeled off to obtain several mother disks.

Further, each mother disk is subjected to the same treatment and electroformed to obtain several stamper disks.

Therefore, a large amount of plastic substrates are produced by plastic molding using the stamper board. Further, on the plastic substrate onto which the focus row of the recording master is transferred by these methods, various films are deposited depending on the intended use, and the plastic substrate is assembled into a final disk.

In addition, in this specification, the nickel master disc,
Transfer disks made of electroformed layers obtained by electroforming in order to transfer the bit strings, such as mother disks and stamper disks, are collectively referred to as "electroformed original plates," and For convenience, nickel master discs and mother discs whose backs are in close contact with glass discs are collectively referred to as "recording master discs."

For example, to explain the manufacturing process of a nickel master disk with reference to the drawings, as shown in FIG. It is produced by cutting the pit row 13 with a laser beam spot and then developing it. In order to obtain a nickel master disk 11 by electroforming the photoresist master disk 10, a conductive film 5 is formed on the surface of the photoresist 4 by silver mirror reaction or the like.

Then, the photoresist master 10 is immersed in an electrolytic solution of, for example, a nickel sulfamate bath, and the conductive film 5 is
By applying current to the conductive film 5, about 0.3 m-
However, if the conductive film 5 is directly energized by the negative electrode 8 of the mounting plate, the structure of the negative electrode 8 becomes complicated. At the same time, it is difficult to form the nickel electroformed layer 3 with a uniform thickness on the conductive film 5.

Therefore, a conductive ring 12 for electroforming is placed on the outer periphery of the photoresist master disk 1O, and electricity is supplied from the entire periphery of the conductive film 5 via the conductive ring 12 for electroforming. That is, the electroforming conductive ring 12 is a ring-shaped member made of nickel or other conductive material with a thickness of about 0.2++n, and is configured to protrude appropriately from the outer periphery of the photoresist master 10. Therefore, the photoresist master 1
The part protruding from 0 is held between a member called a mounting plate consisting of a negative electrode 8 and a holding part 7, and current is passed from the negative electrode 8 to the conductive film 5 via the electroforming conductive ring 12. It is now possible to do so.

Therefore, as shown in FIG. 4, a master disk 11 in which the nickel electroforming layer 3 and the electroforming conductive ring 12 are integrated is formed on the photoresist master disk IO.

Thereafter, after the photoresist master disk 10, the nickel electroformed layer 3, and the electroforming conductive ring 12 are taken out from the electrolytic solution, a nickel master disk 11 is placed on the surface of the nickel electroformed layer 3. The portion that will become the back surface of the nickel electroformed layer 3 and the electroformed conductive ring are polished and smoothed, and then the photoresist master 10 and the nickel electroformed layer 3 are separated. Nickel master board 11 is completed by combining 12 with nickel master board 11.

In addition, when the back side of the nickel master disk 11 is brought into close contact with a glass disk and electroformed under similar plating conditions, polished and peeled to obtain several mother disks, or when the mother disk is subjected to similar treatment. In the case where a stamper plate is obtained by the same method, the nickel electroforming layer and the electroforming conductive ring are formed integrally.

[Problem to be solved by the invention]

However, the electroformed original plate comprising the electroformed layer and the conductive ring obtained in the electroforming process as described above is tightly attached to the glass disk with the outer peripheral end of the conductive ring protruding from the outer peripheral end of the glass disk. Therefore, the outer peripheral edge of the conductive ring tends to come into contact with other members during post-processes such as washing with water and polishing the back surface after the electroforming process, resulting in problems such as separation of the pre-electromotive Yusuhara plate and the glass plate. .

As described above, the above-mentioned separation between the electroforming original plate and the glass disk immediately after electroforming may occur during the subsequent manufacturing process, for example, if the secure fixation of the photoresist layer is lost, each layer formed by the photoresist layer will peel off. There may be problems such as scratches occurring on the replication layer, etc. Also, if the polishing liquid or electrolyte enters between the electroformed original plate and the glass disk from this peeled part, foreign matter may adhere and cause scratches. There was an extremely serious problem in that the number of occurrences increased.

The purpose of this invention is to solve the above problems, and is an electroforming method that can prevent separation between the glass disk and the electroformed original plate, and prevent moisture from entering between the glass disk and the electroformed original plate. Our goal is to provide the following.

[Means to solve the problem]

The above-mentioned object of the present invention is to provide an electroforming method for producing an electroformed original plate to which information of the recording master is transferred by forming an electroformed layer on the recording surface of the recording master, the outer diameter of which is equal to or less than the outer diameter of the recording master. An electroforming conductive ring having a diameter is placed on the outer periphery of the recording surface of the recording master, and electricity is applied to the recording surface of the recording master through the electroforming conductive ring. This is achieved by an electroforming original plate electroforming method characterized by producing an electroforming original plate by electroforming a cast layer.

According to another means, there is provided an electroformed original plate comprising an electroformed layer formed on the recording surface of the recording master in order to transfer information on the recording master, the outer diameter of which is equal to or less than the outer diameter of the recording master. a conductive ring for electroforming that has a diameter and is placed on the outer periphery of the recording surface of the recording master; and by applying electricity to the recording surface of the recording master through the conductive ring for electroforming, the recording surface of the recording master is [Embodiment] Hereinafter, one embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a sectional view of a main part showing the electroforming process of a nickel master disk using the electroforming method of the present invention in the manufacturing process of an optical disk recording medium.

First, as before, photoresist master (recording master) 1
0 is produced by cutting pit rows 13 with a laser beam spot on a photoresist 4 coated on an optically polished glass disk 6, and then developing the photoresist 4. Then, in order to obtain a nickel master disk 1 by electroforming the photoresist master disk IO with nickel, a conductive film 5 is formed on the surface of the photoresist 4 by silver mirror reaction or the like.

Then, an electroforming conductive ring 2 having an outer diameter approximately the same as the outer diameter of the photoresist master 10 is placed on the outer periphery of the surface of the photoresist master g110, and the photoresist master 1
0 is set on a member called a mounting plate consisting of a negative electrode 8 and a holding part 7. At this time, the annular conductive plate 9 connects the electroforming conductive ring 2 and the cathode 8.
The conductive ring 2 for electroforming and the negative electrode 8 are connected to each other.

Therefore, the photoresist master 1O is immersed in an electrolytic solution such as a sulfamic acid nickel bath, and electricity is applied from the entire periphery of the conductive film 5 through the conductive plate 9 and the conductive ring 2 for electroforming. The electroformed nickel layer 3 can be formed on the film 5 with a uniform thickness. By removing the photoresist master 10 from the mounting plate and also removing the conductive plate 9 from the electroforming conductive ring 2, as shown in FIG. The original shape of the master disk 1 in which the cast layer 3 and the electroforming conductive ring 2 are integrated is formed.

Thereafter, after the photoresist master disk 10, the nickel electroformed layer 3, and the electroforming conductive ring 2 are taken out from the electrolytic solution, a nickel master disk 1 is placed on the surface of the nickel electroformed layer 3. )
By polishing and smoothing, and then peeling off the photoresist master IO and the nickel electroformed layer 3, the nickel electroformed layer 3 and the electroforming conductive ring 2 are integrated. The nickel master edition is completed.

At this time, based on the present invention (according to the above-mentioned electroforming method), the outer peripheral end of the electroforming conductive ring 2 does not protrude from the outer peripheral end of the glass disk 6, and the nickel master disk l is connected to the photoresist master disk. 10, there is no risk that the outer peripheral end of the electroforming conductive ring 2 will come into contact with other members during the post-processing process as described above, and the nickel master disk 1 and the glass disk 10 will separate. can be avoided.

Therefore, from the part where the nickel master disk 1 and the glass disk 10 are separated, the nickel master disk 1 and the glass disk 1 are separated.
By entering the polishing liquid or electrolyte between the nickel master disk 1 and the nickel master disk 1, it is possible to prevent foreign matter from adhering to the nickel master disk 1 and causing scratches on the nickel master disk 1.

In the above embodiment, the electroforming process of the nickel master disk was described, but the present invention is not limited thereto. The present invention can be similarly applied to the case where several mother disks are obtained by electroforming under certain conditions, polished and peeled, or when a stamper disk is obtained from the mother disk through similar processing.

〔Effect of the invention〕

As described above, according to the present invention, in the electroforming method of producing an electroformed master plate to which information of the recording master is transferred by forming an electroformed layer on the recording surface of the recording master, A conductive ring for electroforming having an outer diameter equal to or less than the outer diameter is placed on the outer periphery of the recording surface of the recording master, and electricity is applied to the recording surface of the recording master through the conductive ring for electroforming, thereby forming the recording master. An electroformed original plate is produced by electroforming an electroformed layer on the recording surface.

That is, since the outer peripheral end of the electroforming conductive ring does not protrude from the outer peripheral end of the recording master, and the electroforming master is in close contact with the recording master, the electroforming during the post-processing process as described above. It is possible to avoid the risk that the outer circumferential end of the conductive ring for casting will come into contact with another member and the recording master and the electroforming master will separate.

Therefore, peeling between the recording master and the electroformed master is avoided, and the intrusion of moisture and the like due to the peeling phenomenon between the recording master and the electroformed master is avoided, so that scratches on the electroformed layer of the electroformed master are avoided. It is possible to provide a good electroforming method that can prevent the occurrence of such problems.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a main part showing the electroforming process of a nickel master disk using the electroforming method in the manufacturing process of an optical disk based on Embodiment 11 of the present invention, and FIG. 2 is an embodiment U of the present invention.
Figure 3 is a cross-sectional view of the main parts of a nickel master disc using the electroforming method in the conventional optical disc manufacturing process, and Figure 4 is a cross-sectional view of a conventional nickel master disc. FIG. (Symbols in the diagram) 1--Nickel master disk 2-Electroforming conductive ring 3-Electroforming layer 5-Conductive film photoresist glass disk negative electrode Photoresist master disk Nickel master disk electroforming conductive ring 13-Bit string. 7 - Retaining part 9 - Conductive plate (3 others) 1. Indication of the case Patent Order No. 90456 of 1990 2. Name of the invention Electroforming original plate Electroforming method and electroforming original plate 3. Person making the amendment Case and Relationship: Patent Applicant Name (520) Fuji Photo Film Co., Ltd. 4, Agent 100 Address: Tosen 1 Boku Koya Hatsutsugu v 13-chome 8-1 Toranomon Mitsui Building U Floor Eiko Patent Office 6, by amendment Increased number of claims: 07, subject of amendment: paddle 8 in the “Detailed Description of the Invention” of the specification, content of the amendment: (1) “Adhesive scratches j” on page 7, line 17 of the specification. later"
Or insert "Defect".

Claims (2)

[Claims] (1) In an electroforming method for producing an electroformed original plate to which information of the recording master is transferred by forming an electroformed layer on the recording surface of the recording master, the outer diameter is equal to or less than the outer diameter of the recording master. An electroforming conductive ring is placed on the outer periphery of the recording surface of the recording master, and electricity is applied to the recording surface of the recording master through the electroforming conductive ring to form an electroformed layer on the recording surface of the recording master. An electroforming method for an electroforming original plate, which is characterized by producing an electroforming original plate by electroforming. (2) An electroformed master plate comprising an electroformed layer formed on the recording surface of the recording master in order to transfer information on the recording master,
an electroforming conductive ring having an outer diameter equal to or less than the outer diameter of the recording master and placed on the outer periphery of the recording surface of the recording master, and supplying electricity to the recording surface of the recording master through the electroforming conductive ring; An electroformed original plate comprising an electroformed layer electroformed on the recording surface of the recording master.