Tantalum SMD

Tantalum capacitors are a kind of electrolytic capacitor, just like regular aluminum electrolytic capacitors. The difference is that tantalum capacitors use an oxide film based on tantalum (Ta). This results in a very thin dielectric material with higher capacitance per volume and improved high frequency properties. Tantalum capacitors are available as both through-hole (TH) and surface-mounted (SMD). They are typically manufactured in capacitances from 0.1 μF to 100 μF.

An important thing to note is that tantalum capacitors are commonly marked on the positive terminal, not the negative.

Tantalum capcitors have many advantages, for instance much lower ESR (equivalent series resistance) and lower leakage current than electrolytic capacitors, they can also withstand higher operating temperatures (especially in relation to size). They also have relatively good temperature stability. The big advantage of tantalum capacitors is the smaller physical size with its relatively high capacitance and a long life.

Disadvantages of tantalum capacitors include that they cannot deliver high current levels, and that they are only manufactured for lower operating voltages, commonly up to 35 volts. They are also relatively expensive compared to other capacitor types.

One last disadvantage is that tantalum capacitors are highly intolerant of incorrect polarization or overvoltages. If they are exposed to either of these, they are destroyed, with potential for smoke release or explosive results. This sensitivity means that tantalum capacitors are often subject to replacement during repairs, giving them a somewhat undeserved bad reputation. As long as they are protected from harmful voltages, tantalum capacitors are high-reliability components and are often used in equipment with high demands for such, e.g. medical, aerospace or military equipment.