Aluminum Electrolytic Capacitor Anode Foil With The Expansion Of Surface Corrosion Research

With the rapid development of household electrics, automobile and communication techniques, the demand to LSI is increasingly high. In order to further reduce the volume of aluminum electrolytic capacitors and improve the performance, the higher requirement was put forward for the covering corrosion process. In order to improve electrostatic capacity, three kinds of methods have been studied in this paper which are different pretreatments, process parameter for expanding the surface anode corrosion foil and Inhibitor choose.The main study results are as follows:Different pretreatments of aluminum foil have been used in this experiment. The result shows:pretreatments can improve surface environment and enhance effect of corrosion process. Pitting liquid pretreatment is best; it is19.85%higher than those which do not use pretreatments.Different corrosion conditions have different effects. Electrostatic capacity from aluminum foil increase with increasing temperature when it is under70℃, while the pore size decrease in certain range. If it is out of range, electrostatic capacity will steady decline. In addition, density of the foil increased with increasing current density when it is under0.3A/cm2.Orthogonal design has been used to research process parameter for expanding the surface anode corrosion foil in the system of sulfuric acid and hydrochloric acid, based on many single factors experiments. Corresponding factors have been investigated such as concentration of etching solution, current density, temperature, and corrosion time. The optimal corrosion conditions have been chosen through orthogonal test that corrosion temperature is70℃,Ψ (HCl: H2SO4)=1:3, current density is0.25A/cm2, and corrosion time is105sec, et al. The results show that:corrosion foil of high specific volume can be got and specific electric-capacity is as high as99.72μf·cm-2.The research of two corrosion inhibitors (PEG and TU) showed that better surface morphology, higher electrostatic capacity (104.16μf·cm-2and102.54μf·cm-2) and less weightlessness was gained, by adding in adequate amount of inhibitors, which also showed that the result of PEG was a little better than TU.We adopt chemistry surface-enlarging method to the secondary corrosion. The result showed that length of the tunnel hole would not change at invariable temperature.However, to lengthen in duration, holes would be incorporated,10min is great. At the same time, we need to consider the energy bill and weightlessness,70℃is great.