Niobium and tantalum aluminium can form dielectric oxide film on the surface of niobium capacitor. Similar to tantalum capacitors, niobium capacitors are crystallized by amorphous dielectric oxide film.
Effect and dielectric properties of the anode surface and deoxidization reaction and membrane to the metal niobium oxygen diffusion rate is much higher than in ℃ annealing tests showed that the film dissolve nearly but film almost has no effect. In addition, the low-oxygen niobium oxide in the niobium capacitor anodic oxide film is a potential leakage current path caused by conductors and semiconductors. Only by improving the electrical properties of niobium powder and using special niobium capacitor processing technology can dielectric oxide film be stabilized so as to produce capacitors with stable electrical properties. Niobium in the solid electrolytic capacitor can effectively instead of light because tantalum niobium, although cheap metals on the crystal structure and physical and chemical properties are similar but tantalum and niobium electrolytic capacitor is different the electric properties of niobium capacitor during life test the leakage current tend to increase eventually lead to the failure of tantalum capacitor leakage parameters do so within the time had no obvious change but individual has sharply increased some occasional catastrophic failure. The frequency and temperature characteristics of niobium capacitors are very similar to those of tantalum capacitors. One of the important characteristics of niobium capacitors is that there is less ignition during the life test. Typically, the leakage current will become larger and will not be broken down. On the contrary, the failure of tantalum capacitors is that serious breakdown and short circuit will cause the capacitor to catch fire and burn.
Like tantalum and aluminum, niobium can form dielectric oxide film on its surface. The biggest problem of niobium capacitors is that thermal and electrical stress damage the dielectric oxide film, resulting in the increase of DCL, capacitor failure. The degradation of niobium /NbO capacitors is caused by crystallization of amorphous dielectric oxide films and deoxidation of anodic dielectric surfaces. These two effects result in that amorphous dielectric cannot be stable in thermodynamic equilibrium state and oxidation film substrate, and ta-ta2o5 and nb-nb2o5 cannot form thermodynamic equilibrium.
