ABSTRACT
A film element is a thin layer of an electrically conductive material that is applied by different means on an electrically insulating material, often of a ceramic nature. The resistance per square for film elements is normally in the range 1 to 106 ohm, and the thick film elements have the largest span of surface resistance and also the highest resistance. The chapter discusses the influence of locally hampered heat dissipation on the temperature distribution for foil elements. The film elements are divided into thin and thick elements, according to the thickness of the conductive layer. Thin film heaters are used on glass that should remain transparent, such as heating elements on windshields for vehicles, glass for signal lights, and aquariums. A thick conductive film is frequently applied by screen printing. A layer of ceramic material having finely distributed metallic particles can be made conductive by burnishing, that is, rubbing or polishing, for instance, by a rotating polishing wheel.
