Course Overview

This course will cover the latest progress in understanding of failure mechanisms of LEDs that occur at the die, interconnects, and within the package including electrostatic discharge, delamination, and phosphor thermal quenching. The driving factors for precipitating these mechanisms will be discussed to help the developers and users of LEDs control the mechanisms and assess reliability. The course will also inform on the relevant standards for LED testing and reliability assessment, the qualification methods currently in use by major LED manufacturers, and the qualification philosophies that will be most suitable to meet future needs for LED lighting applications.

Course Outline

1. Introduction to LEDs 
  • Characteristics
  • Application areas
  • History
  • Supply chain
  • Structure
  • Types
2. Assessing Reliability
  • Current methods by LED manufacturers
  • Reliability science approach
  • Failure Modes, Mechanisms, and Effects Analysis (FMMEA)
3. Failure Modes and Mechanisms in LEDs
  • Die level
  • Defects (Dislocation, Dark-line, and Dark-spot)
  • Diffusion of dopants/impurities into quantum well
  • Interconnect level
  • Wirebond fatigue
  • Delamination
  • Package level
  • Carbonization of encapsulant
  • Encapsulant yellowing
  • Cracking (Epitaxial, Lens, Substrate)
  • Solder joint fatigue
  • Tarnishing
  • Electrochemical migration
4. Qualification methods for LEDs
  • LED lifetime
  • Current standards and test procedures for LEDs
  • Issues with current qualification methods
5. PHM technology of LEDs
  • Diagnostic techniques
  • Prognostic techniques
6. Thermal Management Techniques
  • Die level
  • Package level
  • System level
7. Summary
*This course has also been presented as a public offering in College Park, MD.

Past Customers

  • 3M
  • Arcelik R&D
  • Astronics LSI
  • Boeing Co.
  • Case Western Reserve University
  • Ciena Corp.
  • Cisco Systems, Inc.
  • DirectTV
  • Daktronics Inc.
  • ERA Technology Ltd.
  • General Electric Global Research
  • Lamar University
  • Microsoft Corp.
  • Teradyne, Inc.
  • U.S. Air Force Research Lab.
  • Whirlpool Corp.


Dr. Diganta Das
301-405-5323 |
Bldg. 89, Room 1103
University of Maryland
College Park, MD 20742