| 摘要 |
PURPOSE:To prevent the cracking and peeling of a resinous layer, and to avoid the deterioration of the reading and S/N ratio by working the surface of the substrate on the writing side of an optical recording medium or at least the surface on the optical recording layer side into a porous state. CONSTITUTION:Borosilicate glass is most suitable as a substrate, and the surfaces of substrates 1a and 1b worked into a porous state can be used as a heat-insulating layer of the optical recording medium and as an antireflection layer of the glass surface on the air side. the glass surface of the optical recording medium is etched with acid treatment. Namely, the alkaline borosilicate glass is heat-treated in a heating furnace at 400-700 deg.C for 6-2hr to separate and form a phase contg. a small amt. of the SiO2 component on the surface of the glass. The phase is etched at room temps.-100 deg.C for 30sec-15min with acids such as HCl, H2SO4, H3PO4, NaOH, and HF to form porous layers 2a and 2b composed of <=100Angstrom pores and having 0.2-3mum thickness on the surface of the glass. The film of the optical recording medium 3 is formed by sputtering, etc. |
