Optimization Of Aluminum Electrolytic Capacitors For High Voltage Anode Foil Etching Process

High pressure and high specific capacitance of aluminum electrolytic capacitor will become a trend of development in the future with the electronics industry and integrated development. Mainly using increase the surface area of the anode foil to improve the specific capacitance, the extended surface corrosion will be affected by many factors and the specific capacitance be limited to the complexity of the process. In this paper, the orthogonal experiment, quantum chemistry calculations, impedance spectra method and scanning electron microscopy were used to analyze the current density, respectively, solution temperature, concentration, etching time to impact of corrosion on aluminum foil anode corrosion law. To draw the biggest factor affecting contrast capacitance. The technology and equipment was improved and analyzes the inhibition mechanism of corrosion inhibitor by the factors.First of all, on the basis of the anode foil etching process parameters by orthogonal experiment to determine the scope of hair holes and reaming experimental parameters. The optimal corrosion conditions of pitting had been chosen that the concentration of hydrogen chloride was 0.8～1.2 mol/L, the concentration of sulfuric acid was 2.5～3.5 mol/L, the current density was 0.25～0.35 A/cm2, the current time was 50～70 s, the corrosion temperature was 73～79 ℃. On the basis of the hair hole process parameters, the chemical etching was used to reaming hole. The optimal corrosion conditions of etching had been chosen that the concentration of nitric acid was 1.8～2.2 mol/L, the corrosion time was 11～13 min, the corrosion temperature was74～78 ℃. Draw the greatest effect on the corrosion process factors.Secondly, the corrosion inhibitor was added to increase at tunnel widening process, Quantum chemistry software modules of Material Studio6.0 was used to different types of inhibitor molecules volume chemical analysis, to determine the activity of the molecule inhibitors position with aluminum foil surface adsorption capacity and strength. By the form of bond to analyze the mechanism of corrosion inhibition.Finally, to improve the existing experimental equipment is not good insulation properties of defects, the design of the automatic thermostatic cell cycle by experiment temperature as the main factors. The best solution washair hole was hydrochloric acid 0.8 mol/L, sulphate 3 mol/L, current density of 0.3 A, time 70 s, a temperature of 73 ℃; reaming nitrate 2 mol/L, the etching time was 11 min, corrosion temperature 77 ℃, oleic imidazoline corrosion inhibitor in an amount of 0.1 g/L. In this process can be further increased capacitance.