Niobium oxide is a sister metal to tantalum, and shares many chemical characteristics with it, in addition to a few advantages of its own when used as a capacitor dielectric.
Niobium capacitor technology has existed for decades, but its inherent direct current leakage instability and the lack of high purity niobium metal powders combined to arrest the development of this class of capacitors until recently. Now the development of special doping techniques to improve the DCL performance of niobium oxide capacitors and the scaling up of niobium powder production have resulted in viable commercial production, and manufacturers such as AVX and Vishay produce several series of surface mount niobium capacitors for commercial, industrial and automotive applications.
ADVANTAGES OF NIOBIUM OXIDE CAPACITORS
Its thin dielectric oxide layer and high dielectric strength combine to produce high volumetric capacitance ratings than compare favourably with tantalum capacitors. It is this affinity with long-established tantalum technology, plus the advantages outlined below, that make niobium oxide devices a growing sector of today’s capacitor marketplace.
- Abundance: an important advantage of niobium is the abundance of niobium ore in nature relative to tantalum ore; this relative abundance equates to lower cost and better availability within the capacitor marketplace.
- Flame Retardant: niobium oxide has a far higher ignition energy than tantalum which results in a significant reduction (up to 95%) of the ignition failure mode of niobium oxide capacitors when compared to conventional tantalum devices
- High Stability: niobium oxide capacitors are by nature highly stable over time in regards to capacitance, ESR and leakage current
- High Reliability: the natural high reliability performance of niobium oxide capacitors makes them suitable for high performance industrial and automotive applications such as airbag controls, in-cabin entertainment systems, and seat position modules
- Light Weight: Niobium oxide powder is half the density of tantalum powder which makes niobium capacitors a practical choice for portable and wearable electronic devices
- Superior Audio Performance: the clear, noiseless filtering of niobium oxide capacitors meets the requirements of coupling circuits in audio devices, both consumer and professional.
Niobium oxide capacitors are produced using the same moulded case styles and industry standard footprints as conventional surface mount tantalum capacitors, in capacitance ratings up to 1,000µF and voltage ratings from 1.8Vdc to 10Vdc