Ceramic capacitors are chip components that consist of alternating layers of dielectric material and metal conductors (typically AgPd or Ni alloys). Ceramic capacitors are primarily used to filter high-frequency electrical signals and because of their extremely high capacitance-to-volume (C/V) values.
As with electrolytic capacitors, insulation resistance, and therefore leakage current, is driven primarily by the behavior of the dielectric. Insulation resistance is relatively high for ceramic capacitors, with resulting negligible leakage current. ESR is primarily driven by the behavior of the electrolyte. Physically, impedance (Z) is a summation of all the resistances throughout the capacitor, including resistances due to packaging. Electrically, Z is the summation of ESR and either the capacitive reactance (XC), at low frequency, or the inductance (LESL), at high frequency (see Error! Reference source not found.). Dissipation factor is the ratio of ESR over XC. Therefore, a low ESR tends to give a low impedance and a low dissipation factor.