High Dielectric Constant Of Anodic Aluminum Composite Oxide Film Preparation Technique

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 reviewed the development of high dielectric constant oxide films in the world on the basis of how to increase dielectric constant of aluminum oxide films. Three kinds of technologies for composite oxide films growing, which have high dielectric constant, and the related mechanisms were studied. The important results and innovations are as follows:1. Sol-gel technology was used in making composite oxide films which have high dielectric constant. The stable TiO2 sol was prepared by using Ti(OC4H9)4 as precursor and C5H8O2 as chelate additive. The optimal ingredient of TiO2 sol was obtained through many tries based on the principle of the sol-gel technology. A TiO2 layer prepared by dipping in the stable TiO2 sol was deposited on the surface of etched aluminum foils. After heat treatment, the composite oxide films were prepared by a normal formation. The compositions and the configurations of the composite films were tested by means of FT-IR, XPS and AFM. The optimal procedure was obtained by studying the influences of the dipping time, and the annealing temperature on the capacitance increase percentage. The results show that, the capacitance of aluminum foils is increased at the different rated formation voltage, the forming time become so little that the power was mostly saved, but the withstanding voltages of the dipping foils become lower. The dipping time and the annealing temperature are the key factors influencing the capacitance of aluminum foils fabricated by sol-gel technology.2. Cathodic electrodeposition technology was used in making composite oxide films which have high dielectric constant. Titanium peroxide was prepared by Ti(SO4)2 and H2O2, and the optimal ingredient of the solution was obtained through repetitious attempts grounding on the effects of the every composition in the solution of titanium...