LED 亮度 LED 呂 e-mail: cclu@epistar.com.tw
Outline FPD Current Status LED Used in FPD BLU Status LED Efficiency Improve and Cost Down Summary
Outline FPD Current Status LED Used in FPD BLU Status LED Efficiency Improve and Cost Down Summary
Market Status Overview FPD (TV ) LCD Monitor Monitor Forecast CRT Total WW TV Forecast LCD Source: 2006 display search
Source: 2007 ICDL LG. PHILIPS LCD Growth of LCD Market
Source: 2006 display search TFT BOM Cost
Source: 2006 display search LED BLU Weakness
Outline FPD Current Status LED Used in FPD BLU Status LED Efficiency Improve and Cost Down Summary
Source: 2007 ICDL SAMSUNG LCD Advantage of LED BLU
White LED Source: 2007 ICDL LG. PHILIPS LCD
Better Color 100% NTSC Color Image Blue Light R, G, B LED Backlight Module White Light Green Light Red Light R, G, B LED Color Filter 度 LED + CCFL CF LED 不 380 380 430 430 480 480 530 530 580 580 630 630 680 680 730 730 780 780 (nm) 100% NTSC 70~92% NTSC 40~60% NTSC 380 430 480 530 580 630 680 730 780 380 430 480 530 580 630 680 730 780 (nm)
Dynamic Backlight Control 度 10000 1 Saved power ~50% Luminance range: 0~500 cd/m2 (2006FPD ) LED 量 了 1000 LED 亮度 0.05cd/m 2 量
Dynamic Backlight Control Source: 2007 ICDL SAMSUNG LCD
Source: 2007 ICDL PHILIPS Dynamic Backlight Control
Data Control Source: 2006 FPD Yakohama - LGL High Luminance Wide Color Gamut Low Power Consumption High Contrast Ratio
2005 CF less
LED BLU Market Status SONY 40 & 46 Samsung 40 NEC 21.3 SONY 23 Samsung 20.1 SONY 11.1 Fujitsu 7 Toshiba 10.6 SONY 13.3
Source: 2007 ICDL BLU Light Source
Backlight Comparison 1.2x OK Limited Source: 2006 Display Search
Value vs. Require Cost Down What s s your requirement? Best price or additional value? Value up Better Color (over 100% NTSC) Energy Saving Environment Friendly
Challenge of LED BLU Rapid cost down and increase LED efficiency to reach consumers sweet spot. To reduce the power consumption and improve the thermal management would increase the LED efficiency and keep good reliability. Cost LED Cost LED Efficiency Efficiency CCFL BLU Cost Timing
Outline FPD Current Status LED Used in FPD BLU Status LED Efficiency Improve and Cost Down Summary
Factors Affecting Chip Efficiency Internal Quantum Efficiency: Light Extraction Efficiency: Total efficiency = Internal Eff. X Extraction Eff.
Chip Efficiency AlGaInP LED (12 mw @ 20 ma, 620 nm) External QE. = Internal QE. X Light EE. 30% = 80% X 36% InGaN LED (21 mw @ 20 ma, 450 nm) External QE. = Internal QE. X Light EE. 38% = 50% X 72%
Improvement of Extraction Efficiency with or w/o DBR surface texturing DBR design Transparent substrate design Mirror reflector design Chip shaping Surface texturing
High Efficiency AlGaInP Products Current spreading P on N DBR design Metal Mirror Adhesive Organic Mirror Adhesive N-P N on P ITO GaAs GaAs Si Si Absorption substrate P on N Thick GaP Transparent substrate P on N Thick GaP High Brightness GaAs GaP 15 lm/w 25 lm/w 50 lm/w (5 mmφ package @ 615 nm, 20 ma, after 2 min drive) Bonding Ultra High Brightness
InGaN LED Performance Improvement Chip Shaping Bonding OSRAM Surface texturing Epistar TCL ITO ITO with cavity
Performance Record LAB AlGaInP Lumileds Osram Epistar Epistar Announce Apr-01 Apr-04 Apr-05 Apr-05 LPW 102 lm/w 108 lm/w 122 lm/w 101 lm/w Wd(nm) 611 615 594 617 IF(mA) - 10 10 10 chip size 14 mil 14 mil 14 mil 14 mil InGaN Nichia Lumileds Osram Cree Epistar Announce Dec-06 Feb-07 Feb-07 Jan-07 Mar-07 LPW 150 lm/w 115 lm/w 480 mw 70 lm/w >380 mw Wd(nm) white white ~460 white ~460 IF(mA) 20 350 350 350 350 chip size ~ ~ ~ ~ MP Epistar 80lm/W 615nm 20mA 14mil Epistar 320mW 615nm 350mA 45mil
Epitaxy Technology MOVPE (MOCVD): Metal-Organic Vapor Phase Epitaxy AlGaInP InGaN
Cost Down Key Factor R G B
Source: Blue 2006 Substrate Trend and ASP
Wafer Size Scale up Source: Mar. 2007 Compound semiconductor Source: Apr. 2007 Compound semiconductor
Cost and Performance Chip Size Cost Efficiency Wafer Size chip size LED cost Wafer size edge effect Cost wafer size Cost down
Current Density and Junction Temperature Effect InGaN LED QE drops as increasing current whereas AlGaInP LED keeps constant. Source: OIDA / US DOE Source: Lumileds White LED life drops in half for every 10 o C increase of junction temperature. 100% Relative Intensity 80% 60% 40% 20% Source: OIDA / US DOE +30 o +20 o +10 o T j,ref 0% 10 100 1,000 10,000 100,000 hrs
Outline FPD Current Status LED Used in FPD BLU Status LED Efficiency Improve and Cost Down Summary
White LED Performance Improvement 200 White LED @ 20 ma OIDA / US DOE Efficacy (lm/w) 150 100 50 Lab. level Production level White LED @ 300 ma Japan 21 OIDA / US DOE Tube fluorescent Compact fluorescent Incandescent / Halogen 0 2000 2005 2010 2015 2020 Source: Nichia/Cree Year HID
Key Issue of LED Application Market Pull Reliability Lm/$ Patent issued Technology Push!
Lighting Your Life Through Diode Emitting