THIN-FILM ELECTRONIC DEVICE

PURPOSE:To prepare an enamel substrate having desirable surface flatness and to produce a high-quality thin film electronic device with the enamel substrate, by coating a metallic core with porous glass containing voids of a diameter of 2mum or less to provide the enamel substrate, and forming an electronic circuit thereon with thin film elements. CONSTITUTION:A coating of an enamel substrate must contain therein voids with a maximum diameter of 2mum or less. In order to obtain such substrate, glass frit powder having a mean particle diameter of 1mum or less and 80% or more of which has a diameter of 6mum or less is slurried, and a metallic core 1 is dipped in the slurry so that the glass frit is closely adhered on the surface thereof by electrophoresis or the like. The metallic core thus coated is baked at a temperature lower than the resistive temperature of the material of the metallic core 1, so that the glass frit particles in the resulting coating can form a composition fusion bonded with each other or to the surface of the metal with their particle diameter substantially unchanged in comparison with those before the baking. The enamel substrate is allowed to have fine voids occupying less volume therein and therefor the grade of integration as an integrated circuit thereof can be improved.