Research Of Manufacturing Technology For Niobium Oxide Electrolytic Capacitor

The electrolytic capacitor has been recognized by the market for its light weight,small volume and excellent properties. Tantalum electrolytic capacitor has goodperformances, but its price is higher and higher since the shortage of resources oftantalum came up in1999. Although aluminum electrolytic capacitor is cheap, itscapacitance changes a lot when used and it will be likely to fail in the long time storage.The quantity of resources of Niobium is dozens of times of that of Tantalum and theniobium electrolytic capacitor also has as good electrical properties as that of tantalum.In the last few years, scientists have improved that the niobium electrolytic capacitorusing pure niobium as substrate can’t meet the market requirements for its bad leakagecurrent characteristic and instability. So scientists paid attention to the NbO. NbO hasconductive capability as metal. The niobium electrolytic capacitor using NbO assubstrate called Niobium oxide electrolytic capacitor may overcome the defect and meetthe market requirements. It’s necessary to explore and discuss the manufacturingtechnology for Niobium oxide electrolytic capacitor.The manufacturing technology for Niobium oxide electrolytic capacitor is similarto that of Tantalum electrolytic capacitor. So the thesis is based on the themanufacturing technology for Tantalum electrolytic capacitor and the production line ofTantalum electrolytic capacitor. This thesis mainly does researches on pellet weldingprocess, anode oxidation process and MnO₂decomposition.Firstly the relationship between the density of pellet and the electrical properties ofNbO capacitor is studied. And then the most suitable density for the production of NbOcapacitor is chosen. The fluidity of the NbO powder has a decisive impact on the qualityof anode pellet in pellet welding process. The relationship between the fluidity of theNbO powder and the quality of anode pellet is explored by observing the surfacemorphology of the pellets. Heat treatment can improve the leakage current characteristic,so a serie of temperatures is designed to investigate how the heat treatment affects theleakage current characteristic. Then the most suitable heat treatment temperature ischosen. In anode oxidation process, a detailed study is made on the effects on the threemain technical parameters on the properties of the anode by orthogonal experiments and analysis of variance. Using the two methods, the most suitable technical parameters foranode oxidation process are chosen. In the MnO₂decomposition, there is always aproblem that after the MnO₂decomposition, the capacitance of anode decreases. So theeffect of the times of the lightest manganese nitrate solution on the rate of capacitancewithdrawing is studied and the most suitable times of the lightest manganese nitratesolution is determined.