| 摘要 |
PROBLEM TO BE SOLVED: To make it possible to obtain thicknesses uniform over inner and outer peripheries even if the thickness of the adhesives for bonding two sheets of substrates to each other is set slightly thick. SOLUTION: This optical disk is formed by disposing and bonding substrates 2a, 2b having first bonding surfaces (c), (f) which are disposed on a center hole H side, have first bonding widths (b), (e) and are formed toward the outer peripheral side from the center hole H and second bonding surfaces 2a1 , 2b1 which have the second bonding widths (a), (d) larger than the bonding widths (b), (e) and are formed toward the outer peripheral side than the first bonding surfaces, to each other. When the first bonding surfaces and the second bonding surfaces are adhered to each other via the adhesive materials 5, the optical disk is so constituted that the thickness of the adhesive layers at the adhesive surfaces of the second bonding surfaces to each other is made larger than the thickness of the first bonding surfaces to each other and that the adhesive layers at the adhesive surfaces of the first bonding surface to each other exist between the bonding surfaces. |
