JP2828665B2 - Manufacturing method of stamper for optical disk duplication - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for manufacturing a stamper for duplicating an optical disk.

2. Description of the Related Art Conventionally, as a method of manufacturing a stamper for duplicating an optical disc, a conductive film is formed on a pregroove pattern formed on a glass substrate, and then the conductive film is used as a cathode.
A master is obtained by plating and peeling the glass substrate,
A mother obtained by subjecting the master to a release coating treatment and then Ni plating and peeling from the master, obtaining a mother by subjecting the mother to a release coating treatment and then Ni plating and peeling from the mother to obtain a sun (stamper). Are known, for example, from JP-A-60-197959 and JP-A-61-221392.

Here, in such a conventional method, after the mother is separated from the master and after the sun is separated from the mother, the surfaces of the mother and the sun are washed with water. In this case, a pit inhibitor (surface tension reducing agent) in the plating bath
The surface active agent has a hydrophobic group adsorbed on the surfaces of the master and mother on the side to be originally copied, and a hydrophilic group protrudes from the plating solution. The mother and the sun are duplicated on this surface by plating.

Problems to be Solved by the Invention However, considering, for example, a case where the mother is duplicated from the master, the mother is plated on the hydrophilic groups of the surfactant adsorbed on the master, so that the mother after the separation is removed. Has a hydrophobic group on the surface because the hydrophilic group of the surfactant is adsorbed, and thus becomes water-repellent.

Such a phenomenon will be described with reference to FIG. First,
As shown in FIG. 2 (a), the surfactant in the plating bath usually directs the hydrophilic group indicated by the symbol to the aqueous solution side, so that the hydrophobic group indicated by the symbol Ni is adsorbed on the surface of the master 1 made of Ni. The illustrated example is a case of using the lauric acid ester sodium salt _{(C 12 H 25 -OSO 3 -Na} ) as a surfactant, the hydrophobic group is C ₁₂ H ₂₅ becomes an alkyl group, a hydrophilic group OSO ₃ And represents Na. As shown, such a surfactant is an anionic (anionic) surfactant, and when dissolved in water, a portion having a hydrophobic group becomes an anion. When the mother 2 is duplicated from the master 1, the outermost surface of the mother 2 is adsorbed by the anions having a hydrophobic group of the surfactant (the anion portion is hydrophilic). As shown in FIG. 2 (b), the side that comes into contact with water has a hydrophobic group protruding to become water repellent.

Therefore, the washing water cannot be completely removed in the drying step, remains as stains, and has many defects.

This is the same in the step of duplicating the sun from the mother.

Means for Solving the Problems After forming a conductive film on a pre-groove pattern formed on a glass substrate, a Ni is plated with the conductive film as a cathode, and the glass substrate is peeled off to obtain a master. In the method of manufacturing a stamper for optical disc duplication, a mother is obtained by subjecting a release coating to Ni plating and peeling from the master to obtain a mother by subjecting the mother to a release coating and then peeling off from the mother by Ni plating. After the mother was peeled off from the master, the mother surface was subjected to a hydrophilic treatment for 2 minutes or more, and after the sun was peeled from the mother, the sun surface was subjected to a hydrophilic treatment for 2 minutes or more.

Action After the mother is peeled off from the master, this mother surface is treated with hydrophilicity, and after peeling off the sun from the mother, the sun surface is treated with hydrophilicity. Is replaced by Therefore, a high-quality stamper having few defects without producing stains or the like is manufactured.

Embodiment A first embodiment of the present invention will be described with reference to FIG.
First, a conductive film is formed on a pre-groove pattern formed on a glass substrate.
A master is obtained by plating and peeling the glass substrate. Next, after the master is subjected to a release coating treatment, it is plated with Ni, and then separated from the master to obtain a mother.
After the peeling, the mother is subjected to a hydrophilic treatment for infiltrating into isopropyl alcohol for 2 minutes, then washed with water and dried. After the surface of the mother having been subjected to such a treatment is subjected to release coating treatment, it is plated with Ni and peeled from the mother to obtain a sun. After this peeling, a hydrophilic treatment for infiltrating the sun in isopropyl alcohol for 2 minutes is performed, and then the water is washed and dried.

About 10 suns duplicated by such processing,
When the defect rate of the data portion was measured, the characteristic A was found in FIG.
As shown by, the variation is 10 ^-7 or less, and the variation is small. In the figure, the defect rate is shown with a variation width of ± 2σ _n−1 centered on the average value of 10 suns.

Next, a second embodiment of the present invention will be described with reference to FIG. In this embodiment, reproduction is performed by the same method as in the above embodiment, except that hydrophilic treatment of mother and sun by isopropyl alcohol infiltration is performed for 3 minutes instead of 2 minutes. The defect rate of the data portion was measured for the 10 suns replicated by such a process. In this case, too, as shown by the characteristic B in FIG. 1, the defect ratio was 10 ^-7 or less, and the variation was small. It is.

By the way, as a comparative example, when duplicating by the same method as the above-mentioned example, the hydrophilic treatment by isopropyl alcohol infiltration of the mother and the sun was performed for only 1 minute, and the data of 10 suns duplicated. When the defect rate was measured, in this case, as shown by the characteristic C in FIG. 1, it was about 10 ⁻⁶ , and the variation was widened. Therefore, hydrophilic treatment for mother and sun is 2
It is good to be more than minutes.

Effects of the Invention The present invention provides a hydrophilic treatment of the mother surface for 2 minutes or more after the mother is peeled from the master as described above, and a hydrophilic treatment of the sun surface for 2 minutes or more after the sun is removed from the mother. Since the surface of the mother and the sun after peeling can be replaced from water repellent to hydrophilic, and therefore, a stain due to water repellency does not occur, so that a high quality stamper with few defects can be manufactured. is there.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a characteristic diagram showing defect rate characteristics according to the first and second embodiments of the present invention, and FIG. 2 is an explanatory diagram showing a water repellent phenomenon by a surfactant.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields investigated (Int. Cl. ⁶ , DB name) G11B 7/26 B29D 17/00 B29C 33/38 B29L 17:00

Claims (1)

(57) [Claims] A master is obtained by forming a conductive film on a pregroove pattern formed on a glass substrate, Ni plating using the conductive film as a cathode, and peeling the glass substrate to obtain a master. In the method for manufacturing a stamper for optical disc duplication, the mother is obtained by treating the motherboard by Ni plating and peeling the master from the master, and by removing the mother from the mother by subjecting the mother to a release coating treatment and then peeling the mother from the mother. After separating the mother from the master, the mother surface is subjected to hydrophilic treatment for 2 minutes or more, and after the sun is separated from the mother, the sun surface is subjected to hydrophilic treatment for 2 minutes or more. To manufacture a stamper for duplicating an optical disk.