Abstract
The 10 key on-going technologies to make the LEDs to generate more light than heat and finally take the competitive lead in lighting markets.
A new Yole Développement / EPIC report
Breaking the Profit-barrier with Ultra-High Brightness LEDs
LED component volumes have been driven mainly by mobile phone sales recently, showing an incredible annual compound growth rate of more than +45% per year.
Due to the strong pressure on component prices, revenue growth has been moderate: only +8% over the last 2 years.
"It is now clear that LED market needs to expand into new and profitable sectors with higher margins. We believe that this growth will come from 3 additional application areas: automotive lighting, architectural lighting and general illumination, in addition to the LCD backlighting market." says Philippe Roussel senior analyst at Yole Développement, in charge of Compound Semiconductor activity.
To capture the profits in these application sectors, significant improvements are needed in LED performance, especially in $/lumen and in Lumens/Watt at full power. New approaches manufacturing technologies are required at all levels: materials, design, front-end, back-end and packaging, in order to profit from the potential of Ultra-High Brightness LED: UHB-LEDs.
More power and efficiency leads to higher margins and profits
EPIC Secretary General Tom Pearsall points-out: "Recent announcements from LED manufacturers show very impressive results on the lm/W efficiency parameter. (150 lm/W has been proved in laboratory), but only at low-current (<20mA) low-power operation.
The difficulty in obtaining both high power and high efficiency simultaneously underscores the immediate need for dramatic improvements in manufacturing technologies. Today, no more than 70 lm/W has been demonstrated with high-power LEDs (> 1 Watt). In other words, LEDs still lag behind the performance of fluorescent lamps for general lighting applications.
Today high power LED are generating on the average 75% heat versus only 25% light. Several parameters have to be dramatically improved like:
- Internal Quantum Efficiency
- Electrical losses
- Extraction efficiency
- Phosphor conversion and optics quality
This report describes 10 key manufacturing technologies, in use or under investigation that considerably improved the LED optical output power among:
- New substrate materials
- Laser Lift-Off
- Temporary Bonding
- Transparent top contacts
- Binning
- Surface Texturing
- Phosphor composition and deposition
- …
Table of Contents
- Glossary
- Executive summary
- LED market main metrics and players
- Market segmentation
- LED market volume as a function of LED type
- LED market revenues as a function of LED type
- LED 2006 applications breakdown
- 2001-2012 GaN LED market
- Average retail price of conventional packaged LED
- Estimated worldwide blue LED dies capacity by region in million units
- Major worldwide players and related position on the value-chain: Europe, Japan, Korea, Taiwan, China, North America
- General Illumination market
- Worldwide estimation of generated lumens (lm.hr/year)
- Evolution of white LEDs needs for general lighting
- Market estimation for White-LEDs for general illumination
- Wafers needs for general illumination (2" equivalent wafers, million units)
- Projection systems & light-engines market
- Introduction: Definition of a light engine
- Products which require a light engine
- Light engines market forecast 2006-2011
- Market introduction roadmap for light-engine-based products
- Light engine roadmap for displays
- Digital Cinema Projectors market
- Conclusions: What light sources for projection displays: LED or LD?
- Current status of the LED performance and related technologies p44
- Number of lm requested for various applications and related time-to-market for mass-production
- Main manufacturing steps and related options for GaN-based LED
- Examples of current LED companies process flow-chart
- LED: lateral or vertical structure
- GaN-LED: Emitting colour as a function of In concentration
- Global LED efficiency is the ratio of the final luminous output power over the wall-plug input power
- Internal QE has now reached ~73% for low power LED (I=20mA)…
- … but this value significantly drops as the current (so the power) increases !
- How is the input power dissipated? Average LED optical output power vs. heat generation at different current levels
- Extraction efficiency (?extr.) is strongly linked to the die size….
- Different options to optimize LED performance
- Expected efficiency gains for the future white power LED generation
- Influence of selected improvements on the four key efficiency parameters
- The perfect white LED would include…
- New LED manufacturing techno. to enhance luminous efficiency
- Various techniques to improve white LED efficiency
- New growth substrates for nitride LEDs p62
- Sensitivity to dislocations density in the active layer for optical nitride devices
- Estimated volume of substrates for GaN-based LED production (SiC & Sapphire) 2005-2012
- 2006 sapphire substrates market for LED: price, units and diameter analysis
- 2005-2012 Sapphire substrates market volume for LEDs by diameter & related market value
- 2005-2012 Sapphire substrates market value for LEDs, segmented by diameter
- 2005-2012 SiC wafer diameter evolution for GaN/SiC LED production
- 2005-2012 SiC substrates market volume for LEDs by diameter & related market size
- Sapphire substrates main manufacturers
- Different substrates for GaN epitaxy
- GaN substrates / applications matrix
- Conclusion: Tentative time-to-market of various substrates
- Photonic crystals and textured surface
- Goal of the LED surface modification: enhance light extraction and directional emission
- Photonic crystal vs. Surface texturing
- Photonic crystals: the principle
- Example of photonic crystals based LED Luminus PhlatLight®
- Nano-imprint lithography, a key technology for photonic crystals LED
- Photonic crystals LEDs: New developments
- Photonic crystals LEDs by Laser Holography
- Conclusion
- Laser Lift-Off (LLO) & Flip-Chip p85
- LLO Technique: definition
- OSRAM LED chip technology (ThinGaN® technology)
- LLO equipments
- LLO technique & Flip chip mounting
- The flip-chip mounting: transparent substrates only!
- Flip-chip can be coupled with back-face contact reflector technique
- Schematic fabrication process for wafer-bonded transparent substrate AlGaInP/GaP LEDs
- Transparent top contacts with ZnO
- Temporary Bonding p96
- Temporary bonding: introduction
- Thin wafer handling: different solutions
- Temporary bonding: principle
- Main temporary bonding methods comparison
- Temporary bonding using wax
- Temporary bonding using adhesive tapes
- Example of EVG and TEL temporary bonding tools
- Dicing and Scribing
- Definition
- Techniques, Throughputs and costs
- Number of dies / wafer
- Laser Scribing & Dicing
- Diamond Scribing & Dicing
- Example of JPSA, NWR, Synova and Oxford Laser tools
- Binning
- Binning: Definition
- What is Binning?
- Binning: the criteria
- Binning must prioritize on only one parameter to achieve a proper yield
- Binning: conclusions
- Patents and licenses status in the LED business: The phosphor battlefield
p122
- Patent is part of global IP
- "The NICHIA story": 1995 - 1999
- Some Examples of the GaN LED patent situation
- Main agreements and cross-licenses in LED business
- US and Asia remain the most active regions in LED patents
- EU patents status
- Ranking of the most active companies in LED technology patents
- Main phosphor-related patents from various manufacturers
- Main phosphor technologies in use
- Main phosphor suppliers
- Conclusions
- UV-LED and bulk-AlN: The future of white LEDs?
- Introduction
- What are UV wavelengths ?
- UV emission wavelength depends on the Al content in the AlGaN alloy
- Why bulk AlN to make UV LEDs?
- Current UV-LED state-of-the-art
- Main initiatives in AlN bulk single crystal developments
- Tentative roadmap for 2" AlN single crystal market price & useable area
- Example of current available offers in AlN substrates
- Conclusion
- The "Green Gap"
- Introduction: green is missing…
- Why green wavelengths so hard to get?
- Conclusions
- LED lifetime: new business models are needed…
- Long lifetime can be a market driver for adoption but not a money maker for light source vendors
- General conclusions
- Annexes: Company profiles
- CREE
- Philips Lumileds
- OSRAM
