Classification of Surface Mount Capacitors

Surface mount capacitors have developed into many varieties and series, classified by shape, structure and usage, which can reach hundreds of kinds. They are also called chip capacitors, chip capacitors, with C as the circuit representation symbol. In the SMT SMD practical applications, about 80% belong to multilayer chip ceramic capacitors, followed by chip electrolytic capacitors and chip tantalum capacitors, chip organic film capacitors and mica capacitors are less.

1. Chip ceramic capacitors

Chip ceramic capacitors, also known as chip ceramic capacitors, no polarity distinction, the appearance of the same shape and chip resistors. The main body is generally gray-yellow or gray-brown ceramic substrate, and the number of internal electrode layers is determined by the capacitance value, generally there are more than ten layers.

The size of chip capacitor is similar to that of chip resistor, there are 0603, 0805, 1210, 1206 and so on. Generally, there is no label on the surface, so the capacitance and withstand voltage value cannot be distinguished from the capacitor itself, and must be identified from the package label.

2. SMD tantalum capacitors

SMD tantalum capacitor is called tantalum electrolytic capacitor, which is also one kind of electrolytic capacitor, but it uses tantalum metal as medium instead of electrolyte. Many capacitors with high capacity per unit volume, capacity over 0.33F are tantalum electrolytic capacitors. It has positive and negative polarity distinction, and its negative pole is usually marked on the body. Tantalum capacitors have high capacity, low loss, small leakage, long life, high temperature resistance, high accuracy, and excellent high frequency filtering performance.

The common SMD tantalum capacitors are yellow tantalum and black tantalum, the front and back of the SMD yellow tantalum capacitor, and the black tantalum capacitor. The marked end on the main body (the upper end in the example picture) is their negative pole, and the three numbers marked on the main body are the capacitance value indicated by the three-digit scale method, the unit is PF by default, and the voltage value represents the magnitude value of voltage resistance.

3. Chip electrolytic capacitors

Chip electrolytic capacitors are mainly used in various consumer electronic products, and are inexpensive. They can be divided into rectangular electrolytic capacitors (resin encapsulated) and cylindrical electrolytic capacitors (metal encapsulated) according to different shapes and packaging materials. Chip electrolytic capacitors generally have larger capacity and use electrolyte as dielectric, the distinction between positive and negative polarity is the same as that of tantalum capacitors, but the capacitance value size is generally marked on its main body by the straight label method, and the unit is μF by default. cylindrical chip electrolytic capacitors.