A capacitor is a discrete passive component formed by two conductors, be they sheets or plates separated by a dielectric. Either air or a material.
When subjected to a potential difference, the sheets of the capacitor acquire a certain electrical charge by storing it. Depending on the nature of the dielectric, we will have the different types of capacitors and they will be more appropriate to work with them depending on the type of signal in terms of frequency, voltage, application, etc. There are many types of capacitors, the most used in electronics are:
• Ceramic disc
• Multilayer ceramic
• Polyester (MKT)
• Polypropylene (MKP)
• Air (variable condensers and trimmer)
• Aluminum electrolytes
• Tantalum (Tantalum Electrolytic)
Aluminum capacitors and tantalum capacitors have different types of dielectrics:
Aluminum Capacitors: Aluminum capacitors generally use an aluminum oxide (Al2O3) dielectric that is formed on the surface of an aluminum plate. This layer of aluminum oxide acts as the dielectric and is very thin, allowing for high capacitance in a relatively small space. These capacitors are known as aluminum electrolytic capacitors and are polarized, meaning they must be connected with the correct polarity in a circuit.
Tantalum Capacitors: Tantalum capacitors use a tantalum oxide (Ta2O5) dielectric. Tantalum oxide has very favorable dielectric properties, which makes it possible to obtain capacitors with high capacitance and small size. These capacitors are known as tantalum electrolytic capacitors. Like aluminum capacitors, tantalum capacitors are also polarized and must be connected with the correct polarity in a circuit.
In summary, both types of capacitors, aluminum and tantalum, use specific dielectrics to achieve their high capacitance and compact size characteristics. Each has its own particular advantages and applications, but it is important to remember that both must be properly polarized for proper operation.