Foil Surface Of The Composite Oxide Film Technology

Aluminum electrolytic capacitors have excellent properties such as huge capacitance, high working voltage and preponderant price. Now they have been in the most demand in all kinds of electrolytic capacitors and widely applied in many systems of electronic machines. How to increase capacitance of aluminum foils is the key technology to realize the miniaturization of aluminum electrolytic capacitors. This essay has expatiated the development of high dielectric constant oxide films in the world on the basis of how to increase dielectric constant of aluminum oxide films. A serial of technologies for oxide films growing, which is most fitful for the current etching and formation linkage line. The related mechanisms are also included.The etched aluminum foil treated with phosphoric acid then chromatic acid or with amine solution will do much good for increase of the content of or in the aluminum oxide film and on the conditions of optimized processes the capacitance of homemade aluminum foils can be advanced more than 30 percent at the rated withstanding voltage of 51V. The aluminum composite oxide films with high dielectric constant has been proposed and studied. The processes are described that a layer of valve metal oxide prepared by inorganic salt hydrolyzation is deposited first on the surface of etching aluminum foils. After normal formation, the aluminum composite oxide films can grow up. Using appropriate processes, the capacitance of Aluminum foils is increased about 35% than produce level at the rated withstanding voltage of 51V. The characteristics of resistance to voltage, hydration, fold and pull are all detected.The capacitors made of composite oxide films with high dielectric constant are fabricated. The experiments of lifetime is tested which is done at the temperature of 85℃ for 1100 hours. The rules of tanδand leakage current varying with time are also discussed.The aluminum composite oxide films with high dielectric constant are characterized by analysis of SEM, XPS and other instruments. The growing mechanism and dielectric characteristic of oxide films are investigated.