The increasing demand for light emitting diodes (LEDs) has been driven by a number of application categories, including display backlighting, communications, medical services, signage, and general illumination. The construction of LEDs is somewhat similar to microelectronics, but there are functional requirements, materials, and interfaces in LEDs that make their failure modes and mechanisms unique. This web seminar will present a review for industry and academic research on LED failure mechanisms and reliability to help LED developers and end-product manufacturers focus resources in an effective manner. The focus is on the reliability of LEDs at the die and package levels. The driving factors for precipitating these mechanisms will be discussed to help the developers and users of LEDs control the mechanisms and assess reliability. We will concentrate on the phosphor thermal quenching mechanism to illustrate the uniqueness of LEDs compared with other semiconductor devices.