CBB is one of the most used electronic components in capacitor electronic equipment. It is widely used in circuits such as direct-pass communication, coupling, bypass, filtering, tuning loop, control and so on.
It has the characteristics of small size, high sensitivity, low power consumption, good reliability, low cost and good frequency characteristics, so it is widely used for sound production of various electrical products. Commonly used as a sounding device on small electronic products such as music greeting cards, electronic watches, pocket calculators, electronic doorbells, and electronic toys.
CBB capacitors are a layer of metal film directly evaporated on the paper as an electrode, also known as metalized paper dielectric capacitors. The electrode is a thinner metal film than aluminum foil, which is characterized by its self-healing effect. If the voltage is too high and the dielectric inside the capacitor is broken at a certain point, the short-circuit current will evaporate the metal film where the dielectric is damaged, thereby avoiding a short circuit between the two pole pieces and allowing the capacitor to continue working. Of course, the range of breakdown should not be too large, otherwise it will affect the capacitance of the capacitor. Metal film paper capacitors are usually encapsulated with epoxy resin, so they have good moisture resistance.
Disadvantages of CBB capacitors
1. The capacity stability is not as good as foil capacitors. This is because metallized capacitors are prone to capacity loss in long-term operating conditions and can reduce capacity after self-healing. Therefore, if used in oscillating circuits that require high capacity stability, It is better to use metal foil capacitors.
2, the ability to withstand large currents is poor, because the metallized film layer is much thinner than the metal foil, and the ability to carry large currents is weak. In order to change this shortcoming of metallized film capacitors, there are currently improved high current metal film capacitor products in the manufacturing process. Because the resistance of the metal film capacitor is more excellent, and it is also satisfactory in terms of solderability and self-recovering properties, which greatly saves size space.