The market for high brightness light-emitting diodes is exploding, largely driven applications in displays, signage and general illumination. According a report from PennWell’s Strategies Unlimited, the HBLED market is projected to grow 29.5% per year, reaching over $19 billion by 2014. The application with the highest forecast growth rate is signs/displays, with a CAGR of 60.6% (this includes LED-based TVs). Illumination has the next-highest growth rate, with a projected CAGR of 45.4%.
The LED manufacturing process is somewhat similar to mainstream semiconductor manufacturing, in that it involves a substrate (either sapphire or GaN), deposition of a fairly complex epitaxial structure (by metal organic chemical vapor deposition, MOCVD), followed by wafer processing (contact formation, etch, thinning), die separation and packaging.
As in mainstream semiconductors, the cost of high volume LED production must continually be reduced, both at the chip and packaged device level. We’ll be exploring that in-depth later this month, at the Strategies in Light conference, Feb. 22-24 at the Santa Clara convention center. A four-hour workshop, which I’ll be moderating, will focus on advances in LED manufacturing technology that will be needed to reduce the cost of HB LEDs (to be held Tuesday, Feb. 22nd, 8:00 am -12:00 noon).
Our speakers will be James Brodrick, manager of the solid-state lighting program at the U.S. Department of Energy; Bill Quinn, chief technologist of Veeco’s MOCVD operations; Ravi Kanjolia, chief technology officer of SAFC Hitech; Thomas Uhrmann, business development manager at EVG; Chris Moore, President and CEO of Semilab AMS; and, from Rudolph Technologies, Mike Plisinski, vp and general manager, and Ardy Johnson, vp of corporate marketing.
As with logic and memory devices, LED market growth is largely driven by advances in performance – in this case LED efficiency, measured in lumens/Watt – and reductions in cost. Higher efficiencies are possible through chip design, light extraction technology, packaging methods and driver performance. Costs are a function of the number of LEDS per light output, manufacturing equipment performance/productivity, materials use and, of course, yield.
A roadmap for manufacturing R&D has also been created. Published in July of 2010, the "Solid-State Lighting Research and Development: Manufacturing Roadmap" calls out specific challenges for luminaires, LEDs and OLEDs. The seven big challenges for the first two:
- Luminaire/Module Manufacturing: Automation, manufacturing and design tools for high quality, flexible manufacturing at low cost
- Driver Manufacturing: Improved design for manufacture for flexibility, reduced parts count and cost, while maintaining performance
- Test and Inspection Equipment: High-speed, non-destructive, and standardized equipment
- Tools for Epitaxial Growth: Tools, processes and precursors to lower cost of ownership and improve uniformity
- Wafer Processing Equipment: Tailored tools for improvements in LED wafer processing
- LED Packaging: Improve back-end processes and tools to optimize quality and consistency and to lower cost
- Phosphor Manufacturing and Application: High volume phosphor manufacture and efficient materials application.
Of these tasks, the first two are associated with luminaire manufacturing, and the last four with the LED chip and package. Test and inspection applies to both. Similar challenges exist for OLEDs:
- OLED Deposition and Patterning Equipment: Equipment for high speed, low cost, uniform deposition, and/or patterning of OLED structures and layers.
- Integrated Manufacturing and Quality Control: Methods to integrate the many process steps, to check the quality and compatibility of materials.
- OLED Materials Manufacturing: Advanced manufacturing of organic and inorganic OLED materials
- Back-end Panel Fabrication: Tools and processes for manufacturing OLED panels from OLED sheet material.
While LED manufacturing is similar to that of mainstream semiconductors, it’s perhaps more akin to photovoltaics manufacturing: There are many competitors with similar processes, margins are slim and China has been aggressively building a manufacturing infrastructure.