| 摘要 |
PURPOSE:To improve the corrosion resistance mainly of the side surface and peripheral edge and its vicinity of a recording surface by providing a second protective film to cover a first protective film covering the side surface and peripheral edge and its vicinity of the recording surface. CONSTITUTION:A protective film 3 is formed on a substrate 2, and a recording film 1 is formed on the protective film 3. A protective film 5 is then formed to cover the side surface and peripheral edge part of the recording layer 1. As a result, only the side surface and peripheral edge and its vicinity of the recording surface are covered with the protective film 5. A protective film 4 is further formed to cover the part not covered with the protective film 5 and the protective film 5. As a result, the thickness of the protective film at the step can be increased, and the corrosion of the side surface and peripheral edge and its vicinity of the recording layer due to the infiltration of water, oxygen, etc., from the outside is prevented. |
