| 摘要 |
PURPOSE:To eliminate the wiping of a bled out adhesive and the working of an outside shape after curing by providing a step in the outer peripheral part of each optical disk substrate and sticking the substrates by utilizing the steps. CONSTITUTION:A protective layer 2 consisting of SiAlN, a recording layer 3 consisting of NdDyFeCo, a protective layer 4 consisting of SiAlN and a protective layer 5 consisting of Al are superposed on each polycarbonate substrate 1 and these substrates are stuck to each other by the adhesive 6. Grooves for tracking are previously molded by an injection compression molding on the substrates 1. The step is provided on the outer periphery of each substrate 1. The adhesive 6 overflowing at the time of the sticking, therefore, accumulates in the step part and does not bleed out to the outer periphery of the disk. The generation of double refractions in the disk and the deformation of the substrates are obviated even if the adhesive cures. As a result, the need for wiping away the adhesive and working the outside shape after the curing of the adhesive is eliminated. |
