METHOD FOR FORMING SEMICONDUCTOR BARIUM TITANATE FILM, APPLICATION TO HEATER MIRROR MADE OF PTC THIN FILM LAYER, AND MANUFACTURE OF THE SAME

摘要

PROBLEM TO BE SOLVED: To lower a heat treatment temperature, by carrying out heat treatment on the surface of a substrate with barium titanate fine particles provided between semiconductor barium titanate sintered particles. ;SOLUTION: In a method for manufacturing a positive thermal coefficient(PTC) heater mirror, a reflective film is formed on the back side of a transparent glass substrate, and a solution prepared by mixing semiconductor barium titanate sintered particles having a grain size exhibiting the PTC characteristic and a sol solution containing a barium titanate material component is applied on the surface of the reflective film and then dried. Next, the substrate is heat-treated at 600 to 800°C to precipitate barium titanate fine particles, and the semiconductor barium titanate sintered particles are connected with one another by providing the barium titanate fine particles between the semiconductor barium titanate sintered particles, thus forming a semiconductor barium film exhibiting the PTC characteristic on the surface of the reflective film. Next, lead wires are led out from both positive and negative electrodes formed as films on the semiconductor barium titanate film surface, and an insulating protective film is applied on the back side of the substrate so as to cover the semiconductor barium titanate film and both positive and negative electrodes.;COPYRIGHT: (C)1999,JPO