Ceramic capacitors

Porcelain is another material that works well as a dielectric. Sheets of metal are stacked alternately with wafers of ceramic to make these capacitors. The meshing/layering geometry of Fig. 1 is used. Ceramic, like mica, has quite low loss, and therefore allows for high efficiency.
For low values of capacitance, just one layer of ceramic is needed, and two metal plates can be glued to the disk-shaped porcelain, one on each side. This type of component is known as a disk-ceramic capacitor. Alternatively, a tube or cylinder of ceramic can be employed, and metal ink applied to the inside and outside of the tube. Such units are called tubular capacitors.

Ceramic capacitors have values ranging from a few picofarads to about 0.5 μF. Their voltage ratings are comparable to those of paper capacitors.

Fig. 1: Meshing of plates to increase capacitance.