Optical recording disk mfg. method and apparatus therefor

Abstract

Provided is a method and a device for manufacturing an optical recording disk, capable of forming a good-surface light transmissive layer without involving air bubbles even when the light transmissive layer is formed by using a radiation curable resin such as the ultraviolet ray curable resin of high viscocity and spin-coating. The manufacturing method of an optical recording disk comprizes setting a disk substrate 2 having a recording layer 3 on the stage 21 of a spin-coating device, setting a cap 55 having a gripping shaft capable of gripping on the center of a top surface on the substrate to cap a center hole formed on the center of the substrate, positioning a discharge nozzle on the top surface of the cap so as to set a discharge distance between a discharge surface for discharging a liquid ultraviolet ray curable resin 60 and the mouth of a discharge nozzle 41 to 0.5mm to 5mm, and discharging the liquid ultraviolet ray curable resin from the mouth of the discharge nozzle.

Description

technical field [0001] The present invention relates to a method and an apparatus for manufacturing an optical recording disc. More specifically, it relates to the possibility of preventing air bubbles from being mixed in even when a light-transmitting layer is formed by rotating coating using a radiation-curable resin such as a high-viscosity ultraviolet-curable resin. A method and apparatus for manufacturing an optical recording disc having a light-transmitting layer having excellent surface properties as described above. Background technique [0002] In recent years, optical recording discs typified by CDs and DVDs have been widely used as recording media for recording large-capacity digital data. [0003] These optical recording discs can be roughly divided into so-called ROM-type optical recording discs, which cannot add or rewrite data, such as CD-ROM and DVD-ROM, and so-called ROM-type optical recording discs, which can add data but cannot write data, such as CD-R and...

AI Technical Summary

Problems solved by technology

[0018] However, in order to use an objective lens with a large numerical aperture NA, it is required to form a light-transmitting layer with a thickness of about 100 μm, but it is difficult to form it with a rotary coating device when a liquid ultraviolet curable resin with low viscosity is used as the coating liquid. It has a light-transmitting layer with a thickness of about 100 μm. In addition, when a coating film is formed by a rotary coating device, a large amount of ultraviolet curable resin is scattered from the outer peripheral part of the substrate due to centrifugal force, and there is a problem of low efficiency.

[0019] Therefore, in order to form a light-transmitting layer having a thickness of about 100 μm, it is necessary to use a liquid ultraviolet curable resin with a high viscosity of 2,000 to 10,000 centipoise as the coating liquid. When coating a high-viscosity UV-curable resin on the recording layer to form a light-transmitting layer, when the high-viscosity liquid UV-curable resin is sprayed onto the cover, air is entrained in the liquid UV-curable resin, and Bubbles are generated in the light-transmitting layer, and the quality of the resulting optical recording disc may decrease.

[0020] In the case of spraying a high-viscosity liquid ultraviolet curable resin on a cover rotating at a high speed, air is easily entrained in the liquid ultraviolet curable resin and bubbles are easily formed in the light-transmitting layer. The problem of a significant drop in the quality of optical recording discs

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