LEDs: Lighting the FuturePresenter:

Ted Kretschmer, Mechanical EngineeringMentors:

Dr. Xuejun Fan, Mechanical EngineeringDr. Liangbiao Chen, Mechanical Engineering

OUTLINE

• Importance of LEDs• LED Basics• Technical Challenges• Proposed Research• Summary

Why LEDs?

*Energy Savings Forecast of SSL in General Illumination Applications (DOE) : August 2014

ADVANTAGES OF LEDs

• Efficiency• Longevity• Color• Color Temperature• Inherently Safe

• Incandescent• 15 lm/W

• Halogens• 20 lm/W

• CFLs• 73 lm/W

• LEDs• 94 lm/W

•2030 LED Projections• 220 lm/W *2014 DOE SSL Multi-Year Program (DOE): April 2013

0

50

100

150

200

250

Incandesent

Halogens

CFLs

LEDs

LED Projections

15

20

73

94

220lm/W

LED Efficacy Vs Traditional Lighting

PRINCIPALS OF LEDS

PRINCIPLES OF LEDs

Current

LED HISTORY

1970 1975 1980 1985 1990 1995 2000 2005 20100.001

0.01

0.1

1

10

100

Year

Lumens

Information attained from the DOE Website

MAKING WHITE LIGHT– Phosphorous Conversion– Color Mixing• Red Green Blue

– Hybrid Method

*LED Basics (DOE)

COMPONENTS

TECHNICAL CHALLENGES Thermal Management

TECHNICAL CHALLENGES

• Thermal effects are unique to LEDs• Components have individual reliability

statistics• True system reliability is unknown• Hammer Testing Method

WHAT I PLAN TO DO

• Previous years work• Optimization of white LED with variable currents and

temperatures• One dimensional heat transfer analysis

• Moving Forward• Advanced thermal analysis of LED components• Design of heat sinks that better dissipate heat

• Reliability Study• Individual Components

THERMAL ANALYSIS

• Study of available LED lamps

• Design of optimal heat sink

• FEA Model

RELIABILITY STUDY

• Research component level failure mechanisms

• Correlation study between thermal management and component failure

SUMMARY• LEDs are Efficient• Many Advantages• Technical Challenges• Proposed Research

• Thermal Analysis• Reliability Study

Questions