High Power LED for Solid-state Lighting

Transcription

1 SJ Hon High Power LED for Solid-state Lighting

2 Motivation

3 Outline Market Trends for HB-LED and Lighting Technical Trends & Challenges for LED Lighting AC LED for Lighting Summary

5 10,000 12, ,000 6,000 8,000 0 ($ Milion/USD) HB LED Market Forecast Illumination Signals Automotive Signs Displays Other Mobile Phones and Global HB LED Market Forecast Source : Strategies Unlimited

6 -20%-10% Signs Mobile and Other Illumination Automotive -10%0% Displays Phones Signals Mobile Other 0%10% CAGR 10%20% (2007~2012) 20%30% 30%40% 40%50% CAGR by HB LED Application Source : Strategies Unlimited

7 Revenue 150, , , ,000 90,000 75,000 60,000 45,000 30,000 15,000 0 ($ million, USD) Global Lighting Market Forecast 5.90% Revenue 5.85% Growth Rate 5.80% 5.75% 5.70% 5.65% 5.60% 5.55% 5.50% 5.45% 5.40% Growth Rate Source : Freedona, World lighting F ixture (summarized by DIGITIMES, 2008/12) Revenue will be ~120, 000 Million USD in Market size is about 10 time larger than HB-LED s

8 Lighting Market by Region Incandescent still dominates!

9 Phase-out of incandescent light bulbs Region Country Australia Year '09 '10 '11 '12 '13 '14 '15 '16 '17 '18 Description the Australian Federal Government announced that by 2010, incandescent light bulbs would be banned Asia NZ Philippines Indonia will be doing something very similar as Australia Once put in effect, the country will be the first in Asia to ban incandescent bulbs arrange 50 million pcs of energy saver bulbs at lowest possible price Pakistan arrange 10 million pcs of energy saver bulbs at lowest possible price Japan ban to use incandescent bulb from 2012 Taiwan ban to produce incandescent bulb Ireland proposes to ban traditional incandescent light bulbs in January 2009 UK plans to phase out the sale of incandescent light bulbs by 2011 retailers will voluntarily decline to stock 150 watt bulbs from January 2008, 100 watt bulbs from January 2009, 40 watt bulbs in 2010, and all remaining bulbs by 2011 Europe Holand wants a ban on incandescent light bulbs within 4 years Finland banning incandescent light bulbs in Finland by 2011 Italy banning incandescent light bulbs in Italy by 2010 Belgium intent on banning incandescent light bulbs EU proposed a ban on incandescent light bulbs, planned to come into effect in the near future, but this will not affect existing incandescent bulbs, only the production of new bulbs North America South America Canada United States The plan would ban the sale of incandescent light bulbs, but not their use banned (by January 2014) incandescent bulbs that produce lumens of light. Bulbs outside this range (roughly, light bulbs currently less than 40 Watts or more than 150 Watts) California phase out the use of incandescent bulbs by 2018 New Jersey switch to fluorescent lighting in government buildings over the next three years Brazil Venezuela attempt to phase out the use of incandescent light bulbs attempt to phase out the use of incandescent light bulbs.

11 History of Success for Solid State Technology

12 Haitz s Law

13 OIDA Roadmap 2009 Multi-Year Program Plan FY 09-FY 15 March 2009

14 OIDA Luminaire Roadmap 2009 Multi-Year Program Plan FY 09-FY 15 March 2009

15 Phosphor-Converting LED Multi-Year Program Plan FY 09-FY 15 March 2009

16 Rationale for 200lm/W From Dr. Y. Ohno/NIST October 2007

17 Thermal Issue

18 Power Chip Portfolio Venus-Series Generic approach Saturn-H Series p-pad ITO p-cladding Layer Active Layer n-cladding Layer n-pad p-pad ITO p-cladding Layer Active Layer n-cladding Layer n-pad p-pad ITO p-cladding Layer Active Layer n-cladding Layer n-pad Buffer Layer ESS Lambertian Reflector Bonding Layer Al 2 O 3 Substrate Al 2 O 3 Substrate AlN Substrate ITO on rough p-gan Leaf vein finger design ITO on flat p-gan ESS technology Advanced Epi structure ITO on flat p-gan Lambertian reflector High k thermal substrate Separation of heat dissipation and current path

19 Power Chip Portfolio Venus-Series Saturn-N Series Saturn-H Series p-pad ITO p-cladding Layer Active Layer n-cladding Layer Buffer Layer n-pad N-pad N-GaN Active layer P-GaN Metal layer p-pad ITO p-cladding Layer Active Layer n-cladding Layer Lambertian Reflector n-pad Al 2 O 3 Substrate Conductive substrate Bonding Layer AlN Substrate ITO on rough p-gan Leaf vein finger design Backside electrode Flat surface Lambertian transmittance High k thermal Si substrate Narrower view angle Eutectic layer Advanced Epi structure ITO on flat p-gan Lambertian reflector High k thermal substrate Separation of heat dissipation and current path

20 Evolution of Power Chip Performance 55 Efficiency Evoluation 100 lm/w ma 700 ma EQE (%) 45 AC55 80 lm/w V45 V45B V45C Saturn-N Saturn-H Venus Series Product Portfolio At this moment, only Venus related technique have been applied to AC LED chip. Some advanced techniques for Generic and Saturn can be applied to further improving the performance of AC LED in the future

22 From Power to Illumination Most of the lighting source are powered by AC!!!

23 Worldwide Main Voltage & Frequency

24 From Light Bulb to LED Conventional Lighting AC Electricity Switch / Dimmer $$ & η Bulb / Lamp Conventional DCLED lighting AC Electricity Converter / Adapter Control circuit LED driven via DC AC Electricity Switch / Dimmer LED via AC B

25 AC LED Introduction What is AC LED? AC LED is a single process-integrated LED with multi-cells that can be directly driven by AC utility without extra external device The chip size and the number of cells can be customized to fit for all demands. Different approaches AC LED Module Conventional approach Fabricated by packaging AC LED Single Chip (on-chip AC LED) Innovative concept Integrated by wafer-level process Complete system within a chip

26 Circuit Layout for AC LED Circuit Layout Anti-parallel Type (Diode) Bridge Type Rectifying diode / LED

27 Principle (I) : Dynamic Current Driven Operation Point for DCLED is static V I I v 1 I 1 Q I 1 t v 1 V i-v transfer function of diode t Constant voltage Constant current Operation Point for ACLED is dynamic V I v 2 I 2 I I 2 v 1 t I 1 t I 1 v 1 v 2 V i-v transfer function of diode Alternating sinusoid voltage Alternating non-sinusoid current

28 Principle (II) : Operation Current vs. Efficiency Operation Current VS efficiency If V s-peak =40V V =20V f-on Then Duty cycle (turn off) 1/3 T ( ** power consumption=0) Duty cycle (turn on) 2/3 T Namely, 20~35V, 1/3 T 35~40V, 1/3 T Diodes operate in High voltage regime in a considerably long time High Current Higher Current Density η 1/12T 1/6T Time

29 Principle (III): Power Factor I-V Characteristics of AC LED P optical -P elctrical -I Characteristics of AC LED Power Factor Real Power: Preal Apparent power: apparent 1 = V( t) I( t) dt T The PF of AC LED is 0.8~0.9 T 0 P = V I Preal P. F. = P rms apparent rms Power factor is the ratio of the real power to apparent power: Voltage Current Time How to increase the PF?? 1. Decrease the cell number 2. Reduce the operation current 3. Add resistor

30 A Simple Design Concept DC LED + converter AC LED AC input control circuit AC input Converter LED LED chip Design User-friendly Reliability DC LED + converter worse worse (converter) AC LED better better

31 Lower Cost (lm/$) Approach (4W) Cost Simulation DC LED 300 4W ~35 lm/ USD (if 4 chip per package) USD$0.6~1.0 Driver IC USD$~2.0 Other component USD$~3.0 MCPCB USD$ 1.0 Package USD$ 0.3 Fixture USD$ 0.5 EPI cost $0.5/W cost $ W ~40 lm/ USD (if 4 chip per package) AC LED USD$0.9~1.5 MCPCB USD$ 1.0 Package USD$ 0.3 Fixture USD$ 0.5 Note: The cost of LED chip are only for reference because it depended on performance and chip size.

32 AC LED Target Market Advantages Lower the total cost Less space needed Without reliability concern about converter Easy to be dimmable Niche Market Spot lighting: 3W/200lm; 5W/300lm; 7W/400lm Lamp holder: GU10; E12, E14, E27 100V/110V; 220V/230V

33 Episatr--AC55 Product Type: ES-CABLAC55 10mA: ~ V Wld: ~ nm PS:1.No Resistor 2.η is estimated (Customer Packaging Data) 1W Name X Y Lumen CCT I V Efficiency No./Unit lm K Irms Vrms lm/w Min Max Avg StdDev

34 AC LED Applications Chandelier Table Lamps Recessed Downlight Applications Bulb Type Replace 40W Candle Light 4W AC LED 60W Incandescent 6W AC LED 50W PAR38 15W AC LED AC LED

35 Use AC55 to Form Lamps 4W AC LED 6W AC LED 15W AC LED Type AC LED Module AC55 (1W) X 4 AC55 (1W) X 6 AC55 (1W) X 15 LED Luminous 5700K Luminous 3000K 230 lm 350 lm 160 lm 250 lm 900 lm 650 lm

36 Epistar--AC99 Product Name: ES-CABLAC99 Under development 50mA: 92.5 ~ 95.0 V Wld: ~ nm (Customer Packaging Data) PS:1.No Resistor 2.η is estimated 4W Name X Y Lumen CCT I V Efficiency No./Unit lm K Irms Vrms lm/w Min Max Avg StdDev

37 Technology Challenges of AC LED Luminous Efficiency & Droop Effect Heat Dissipation Electric Power System Variation Pulse and Reverse-bias Driven

38 Efficiency Simulation EPI DC LED 80 lm/w 65 lm/w AC LED η 15~30% η Total Efficiency Comparison AC/DC converter Package MCPCB Fixture 70~85% lm/w ~20% 65 lm/w MCPCB Package Fixture Note: The cost of LED chip are only for reference because it depended on performance and chip size.

39 Efficiency Droop Effect DC LED EQE Constant current Constant η J DC EQE AC LED EQE J RMS J Shorter Duration Longer Duration J RMS η J Peak Varied current Varied η J J Peak J Normally, η@ J RMS < η@j DC due to the longer duration between Jpeak and Jrms

40 Heat Dissipation Venus-Series Saturn-H Series p-pad p-pad ITO ITO p-cladding Layer p-cladding Layer Active Layer n-cladding Layer n-pad Active Layer n-cladding Layer n-pad Buffer Layer Lambertian Reflector Bonding Layer Al 2 O 3 Substrate heat AlN Substrate heat Sapphire k=35 w/m-k AlN k=150 w/m-k Apply bonding technology to AC LED for good heat dissipation!

41 Solution for Power System Variation Adding a resistor I exp { V } I V I larger I smaller I V V Adding a capacitor V rms V V t

42 Pulse and Reverse-bias Driven Compared to DC LED, it s a brand-new operation mode. Therefore, it needs Advanced epitaxial structure : breakdown voltage Modified chip process : reverse leakage Optimized device layout : efficiency Rectifying diode / LED Voltage V f time Bridge type V f

44 Summary Higher energy efficiency and longer life time enable LED to play an important role in driving the transition of lighting industry for next few years. AC LED, a simple and user-friendly solution, is suitable for spot light with relatively lower power fixture like candle light, Incandescent and PAR38. White light AC LED chip with luminous efficiency of 70 lm/w is achieved. Several technology challenges of AC LED have been addressed and need to be further improved for broadening application scope.

45 Thanks for Your Attention