| 摘要 |
PURPOSE:To treat the extrusion of an adhesive by sticking disk substrates each having a recording medium layer on each other so that the respective recording mediums may be opposed to each other, and forming a recessed groove leading from one substrate to the other substrate and including the stuck boundary part of a center hole. CONSTITUTION:Two disk substrates 13 each having a track groove 11 and a recording medium layer 12 are stuck on each other through an adhesive 4 so that the respective recording medium layers 12 may be opposed to each other, and then a recessed groove part 16 leading from one substrate to the other substrate and including the stuck boundary part of a center hole 15 is formed. At this time, the original center holes 17 of the track groove 11 and the disk substrate 13 are jointly formed by injection molding, etc., and formed with excellent accuracy in concentricity. The accuracy in the position of the track groove and the center hole is not disturbed by the formation of the recessed groove part on the part including the stuck boundary of the center holer part, and the excess adhesive at the center hole part can be removed. |
