Accelerated Lifetime Testing and Failure Analysis for Advanced Automotive Grade Ceramic Capacitors (MLCC)

Abstract:
Accelerated lifetime tests for multi-layer ceramic capacitors (MLCC) are performed under increased voltage, e.g. exceeding the rated voltage by a factor of 2 to 5, and elevated temperatures, e.g. 150 °C - 200 °C. This study presents a test setup that allows the online monitoring of leakage current and capacitance during testing. The setup was used to conduct a parameter screening as well as an accelerated aging test for ceramic capacitors of different material classes such as paraelectric, ferroelectric and antiferroelectric dielectrics. Typical failure modes were identified both electrically and by microstructural failure analysis. In addition, the failure location of the devices was correlated to the test parameters such as voltage and temperature to identify possible relations. Screening tests were performed at temperatures up to 200 °C and voltages up to 2500 V. 48 Samples were tested in a 1000 h lifetime test at 1000 V and 175 °C.