Economy Of Scale Will Drive Down Prices Of LEDs

Avnet entered the high brightness LED market several years ago, for a variety of reasons. "One is our belief that this new technology, along with other energy efficient, 'green' solutions, can truly improve the quality of life,"says Cary Eskow, director, LightSpeed, Avnet Electronics Marketing's solid state lighting and LED unit. Eskow has worked closely with OEMs, LED manufacturers and advanced analogue IC and secondary optics vendors since his first patent using LEDs was issued two decades ago. In a conversation with Srabani Sen of Electronics Bazaar, Eskow shares his opinion about the Indian LED market and Avnet's India plans and the latest innovations.

EB: How is the Indian LED market different from other Asian markets?

India enjoys the dual benefits of world renowned engineering talent and a large domestic potential to serve rural areas with LEDs. I believe the scale and scope of the Indian market will accelerate cost effective production,and this coupled with regional power design expertise and creativity, will create opportunities for innovative lighting products. This will not only serve India's needs but also the needs of other countries.

One of the key drivers is the initiative by the Indian government to provide solar based LED lanterns to areas where there is still no power. There is also a strong possibility of the state governments rating office complexes and incentivising them based on the energy saved. Work is under-way in many of the states to use solar based LED lights for lighting up streets, roads and bridges.

EB: How do you see the Indian LED market growing? What potential does it hold?

From a global perspective, sales of high brightness LED components (just the LED device itself) were about $5.1 billion in 2009, according the analyst firm Strategies Unlimited. In 2010, it is forecasted to exceed $8 billion. But most of that revenue growth will be in LED back-light units for TVs. Their outlook for the general purpose LED lighting segment is 32 per cent growth this year, up from 24 per cent in 2009. I believe India will also enjoy a fast growth rate, considering the lower operating and maintenance costs for LED based lighting in the cities, the utility of off grid (solar, etc) LED based lighting in rural areas and home lights. There are a myriad of other markets such as signalling and headlights for two wheelers. In short, the future for LEDs in India is very bright.

EB: What is Avnet's investment plan for India?

Avnet Electronics Marketing has made substantial investments in an engineering and development lab in Bengaluru, staffed with senior LED lighting and electrical engineers. Our Bengaluru team has developed MCU-controlled LED lights, LED driver boards for two wheelers, appliances and many other products. Avnet LightSpeed is our brand for LED focused services and offerings, it is the resource to all our customers in India. As a global company with regional focus, we can also leverage design experts from our Avnet LED development labs in Singapore, Hong Kong, Shenzhen, Taiwan and Shanghai if needed. Some of these labs have advanced photometric analysis equipment, and even anechoic chambers for doing EMI testing. Avnet India also has a large team of field applications engineers (FAEs) who work directly with customers on specific designs.

EB: Do you have any plan to start LED manufacturing in India?

The traditional business model of Avnet Electronics Marketing is to bring value to customers by supplying components from the manufacturers we represent, and providing design and commercial resources such as development labs, local FAEs and sales representatives. We also provide logistics services and supply chain solutions. We don't manufacture end products; our customers do. We design evaluation boards to help customers, and some LED suppliers now offer light modules to simplify the task of designing an LED product and reduce time-to-market. Today, that is about as close as we come to off-the shelf LED lighting products.

EB: What challenges are you facing in India? How do you intend to resolve them?

Most people, irrespective of their technical training or background, are not as familiar as they need to be with high brightness LEDs. This is the first challenge we face--not just in India but globally. Very careful attention must be paid to optics, thermal management, interpreting LED manufacturer data sheets and selecting the optimum LEDs. Today, Avnet Light Speed has authored and published over 40 articles on LED based design techniques and issues; delivered technical papers at many industry, architectural and academic symposiums and made presentations at major LED conferences--all in an effort to close the 'knowledge gap' between the science of designing LED semiconductors and the art of developing real world products that incorporate them.

EB: How the prices of LED products can be brought down?

Economy of scale will drive down the prices of LEDs and low cost production processes such as printing will drive down the cost of OLEDs. On the other hand, the costs associated with alternative light sources will rise. Energy costs are at a premium, this will only worsen, thus promoting low energy lighting. Ecological concerns are becoming more important, and the fact that LEDs (unlike tubelights) have no mercury is the key. Faced with these issues, many governments are making LEDs even more cost effective through incentives, tax rebates and outlawing incandescents. Safe, efficient and eco-friendly lighting is here to stay.

EB: What are the latest innovations that are happening in the LED sector?

Three areas of focus for LED manufacturers are efficiency, uniformity and light output. Efficiency in terms of lumens per watt is increasing steadily but data reported in the laboratory is rarely seen in commercial practice. This is because efficiency drops as the LED die size increases or die temperature is raised or when the phosphor mix used is towards the 'warm white' end of the colour temperature scale. It's not uncommon to see high brightness LEDs operating with greater than 80-100 lumens/watt in available lighting products now, although some LED manufacturers tout greater than 200 lumens/watt in the lab. Uniformity comes into play with architectural lighting. Specifiers want lights that have the same colour temperature when they are placed side-byside, to avoid the visually unpleasant odd 'bluish' or 'reddish' light in a row.Crafting white LEDs with a specific correlated colour temperature (CCT) within a narrow range is difficult.

Light output is increasing with steady improvements in the semiconductor materials used, better phosphors, innovative physics (such as photonic lattices) and engineered packaging. It may seem odd that packaging can impact light output, but it does. This relates to the temperature of the LED's die. It is important to keep it as cool as possible so that the LED can operate for tens of thousands of hours as per customers' expectations. But if the LED die is placed in a package which has a significantly large thermal resistance, less heat flows through the package into a heat sink or SynJet cooler. To prevent overheating, LEDs in such packages must be underdriven. Underdriving LED yields less light. So, we generally want the best LED die with the high conversion efficiency phosphor placed in a package with low thermal resistance.

EB: What are the Avnet's latest offerings to the Indian market?

There are quite a few, so I'll touch on two of the most interesting products. One is a new family of ultra bright LEDs from Luminus Devices, using a technology called 'photonic lattices'. Essentially, these LEDs have a special nano scale patterning on the semiconductor die. The patterns are spaced at intervals near the wavelength of light and based on the physics of electromagnetic radiation, they act as wave guides and effectively 'tease' more light energy (photons) out of the LED. Think of it as an atomic scale lens. Some of these photonic lattice LEDs can produce over 6,500 lumens of light per device! That's at least six times more light than a typical 75W incandescent light bulb.

Our second offering is a new technology--a special cooling system for LED based products called SynJet. LEDs radiate energy is in the form of visible light and not infrared (heat), so LED products generally need some type of cooling. When very large metal heat sinks are not the option, engineers may opt for fans, however, fans are noisy and notoriously unreliable, which severely compromises the lifetime of the LED. The new SynJet solution from Nuventix cools LEDs without any fan; it creates micro vortexes of air by moving a diaphragm in a precise mo-tion profile. As a result, tiny jets of air are generated which flow across the surface, and these expand into larger air movements--all without any motor or rotating parts. They are about 10 times more reliable than fans.