What are the electrical characteristic parameters or quality reliability tests related to capacitors? What are the definitions of the parameters? What are the purposes of the tests?

  • Capacitance (C):
    “Capacitance” is the ratio of electric-charge’s quantity (Q) to voltage (V) between electrodes. (Q = CV) The purpose of measurement is to check permittivity, thickness, integrity of dielectric and effective area between electrodes.
  • Equivalent series resistance (ESR/Rs):
    “Equivalent series resistance” is the sum of lead, electrode, contact resistance, and equivalent resistance caused by loss of dielectric hysteresis and polarization. The purpose of measurement is to check lead, electrode, contact, and dielectric polarization. In high current charge and discharge application, the resistance causes temperature rising to affect the characteristics of capacitors.
  • Dissipation factor (D):
    “Dissipation factor” is the ratio of equivalent series resistance (ESR/Rs) to capacitive reactance (X). (D = ESR/X) About the purpose of measurement, please refer to “capacitance” and “equivalent series resistance”.
  • Leakage current (LC) and insulation resistance (IR):
    “Leakage current” and “insulation resistance” is the current and resistance measured at constant voltage after the dielectric completely polarized. The purpose of measurement is to check crystallographic defects, impurity density, and bandgap width of the dielectric.
  • Ripple current test:
    “Ripple current test” is a reliability test by applying a AC ripple current on DC voltage output for a long period of time. The purpose of test is like “equivalent series resistance”, but also including the evaluation of heat dissipation design.