PURPOSE: To improve the absorption factor for solar heat and the heat resisting property of the absorber by a method wherein copper electroless plating is applied over the surface of a substrate, at least the surface of which is nickel, and said plated layer is oxidatively treated in order to obtain a selective absorber film of cupric oxide.
CONSTITUTION: The solar heat absorber uses a substrate, which is made of solid nickel or on the surface of which a nickel film is applied, as a metal basis. Said nickel substrate is copper electroless plated and, after that, oxidatively treated with chemical conversion treatment solution in order to convert the copper plated layer over the surface of the substrate into the selective absorber film consisting of cupric oxide. Said copper plating is performed with the contact of the surface of the substrate with acid solution containing copper ions by immersing the nickel substrate into the acid solution containing copper ions. In such a manner as described above, the solar heat absorber with enlarged absorption factor and excellent heat resisting propety can easily be obtained.
HATSUSHIRO MASAHIKO
FUJII MASAHARU
