| 摘要 |
PURPOSE:To reduce the temperature rise of a mirror and improve durability and reliability by forming the substrate of the mirror with aluminum nitride ceramic, forming a surface smoothing film on the surface, and forming a reflecting film on it. CONSTITUTION:A surface smoothing film 2 is provided on a substrate 1 made of aluminum nitride ceramic (AlN 99.9wt.% or above), a reflecting film 3 is formed on it, a reflecting film 3 is formed on it, and the surface is formed as the reflecting surface of a mirror. Multiple lugs 1a are formed as cooling fins on the back face of the substrate 1 on the opposite side to the reflecting surface 4. The heat conductivity of the substrate 1 is very high, the heat of the reflecting surface 4 is easily transferred to the back face side of the substrate 1, and the temperature rise of the reflecting surface 4 can be reduced. When the lugs 1a are cooled with cooling water, the cooling efficiency of the mirror can be increased. When SiC or AlN is used for the material of the smoothing film 2, the heat of the reflecting surface 4 can be easily released. When gold, platinum, and SiO2 are laminated to form the reflecting film 3, the heat resistance can be further improved. |
