Chip capacitors destined for high reliability testing are often designed with an added margin of safety, namely maximization of the dielectric thickness, and tested extensively for electrical properties prior to burn-in (e.g., capacitance, dissipation factor, and insulation resistance).
Meters such as the Fluke 110, 170, and 180 series can provide the required data necessary to determine the presence of a failed capacitor. Although other test methods are available, such as live testing, this technical note is centered on testing capacitors in their de-energized state.
Due to their relatively low capacitance (0.20uF to 100.00uF), testing of the capacitors can be done with many standard digital multi-meters (DMM's). Meters such as the Fluke 110, 170, and 180 series can provide the required data necessary to determine the presence of a failed capacitor.
The voltage rise varied from 200 to 400 V/sec. Disc ceramic and thin film capacitors of different value and different nominal voltages were tested. Experiments have shown that the breakdown voltage for all types of the capacitors tested is about ten times more than the nominal voltage of the capacitors.
It is therefore recommended that externally fused capacitors be tested before replacement in situations where the external fuse has blown. For internally fused capacitors, testing is required as the fuse is not visible. The following test procedure requires the capacitor/harmonic filter bank to be grounded and disconnected.
Dielectric formulations and chip capacitors are often tested for reliability under voltage and temperature for specified time periods, a process referred to as burn-in or voltage conditioning. The specifications applicable to burn-in of multilayer ceramic capacitors (MLCCs) are MIL-C-55681, MIL-C-123 and MIL-C-49467.