Tantalum Capacitors 101

A capacitor functions much like a battery in that it stores and charges electrical energy. It is composed of two conductive plates separated by a non-conductive substance called a dielectric. One plate is positively charged (the anode) and the other is negatively charged (the cathode). The dielectric is necessary to keep the opposing charges separate.

Any non-conductive material can be a dielectric, but tantalum is a common choice. According to global electronics company Vishay, tantalum powder creates a thin dielectric layer in the capacitor, which produces high capacitance values. A capacitance value indicates the ability of a capacitor to store electrical charge and is measured in farads.

The capacitance of a tantalum capacitor can be improved by increasing the surface area of the tantalum powder that is used in the device.

Tantalum is a blue-gray metallic chemical element that is great for conducting heat and energy. It is also ductile and malleable, making it very flexible for different applications. However, the majority of tantalum is used to manufacture capacitors for the electronics industry.

Tantalum capacitor applications

Tantalum capacitors play a primary role in the electronics sector, particularly with smaller devices. They can charge circuit boards with electricity and are therefore useful for anything containing a circuit board, such as a smartphone or computer. They are best suited to charging smaller electronics rather than larger ones because they are minimal in size and can function long-term in these situations.

In addition, the high quality and reliability of tantalum capacitors makes them a good fit for high-stakes uses like medical electronics and space equipment.

Comparison: Tantalum and aluminum capacitors

Aluminum capacitors are the base, standard choice of capacitor, but tantalum has a few advantages over this type. For instance, aluminum electrolytic capacitors are unable to withstand and operate in harsh, hot environments, so they are often replaced by tantalum capacitors. The latter are much more tolerant of sustained heat and are also more reliable under these conditions.

Additionally, tantalum capacitors are less likely to dry out over time compared to aluminum ones. This is an important feature because drying causes a capacitor’s ability to store an electrical charge to decrease. However, tantalum capacitors tend to be more expensive than other options, including aluminum ones.

Comparison: Tantalum and ceramic capacitors

Ceramic is another element that is frequently utilized as a dielectric in a capacitor. According to Engineers Edge, it functions well as a dielectric because it allows electrostatic repulsion and attraction to occur across its surface.

The two main types of ceramic capacitors available are disc and multi-layer ceramic (MLC). All types generally have a fixed capacitance value, unlike tantalum capacitors, but they usually fall on the lower end of capacitance. Ceramic disc capacitors are beneficial in situations that require accuracy in a small space at a low cost. MLC capacitors are good when a device needs a high capacitance in small space, according to Engineers Edge.

Because they are less costly than tantalum capacitors, ceramic capacitors are the most cost effective solution and also leave the smallest footprint.