Light emitting diode(LED) plays important role in illumination applications such as general lighting, automotive, and outdoor lights due to their high reliability and energy saving elements. The long lifetime is one of the main advantages of LED and thus, the Accelerated Life T(ALT) is used to help achieving the target life time. This paper presents the investigation of ALT models and failures for LED in recent literatures. LED reliability improvement technologies will be discussed finally.

Abstract
 1. INTRODUCTION
 2. LIFE PREDICTION METHODS AND RELATED RESEARCHES
  2.1 Defining LED useful life
  2.2 Life prediction methods
 3. FAILURES OF LED REPORTED IN RECENT RESEARCHES
  3.1 Failure mode and mechanism
  3.2 Failure causes.
 4. LED RELIABILITY IMPROVEMENT TECHNOLOGY
 5. CONCLUSION
 REFERENCE

• Liu Qiang(Department of Industrial and Management Engineering Daegu University)
• Won Jung(Department of Industrial and Management Engineering Daegu University)