Reliability Failures in Small Optocoupling and DC/DC Converter Devices

In power electronics, often control and power part are at different electric potentials. Thus, electrically isolated coupling of them is performed by optocoupling devices. Also, isolating DC/DC converters are in use. While such systems are dedicated for high reliability application, weak points within these small components generate problems to the system reliability. The paper outlines most common weakness, as optocoupling internal LEDs, packaging problems and hybrid components in use at their electrical limits