Category Archives: LED Packaging and Testing

The lighting control systems marketplace has been in a state of transition in recent years. Changing energy efficiency codes, new construction project increases, wireless technology benefits, increases in LED lighting adoption and conservation initiatives have been the key factors driving the growth of the lighting control systems market in the US. The total United States lighting controls market is estimated to be well over $1 billion by the end of 2013. This figure includes lighting controls, devices, systems and gears. The market is expected to show a considerable growth through the forecast period. The systems market is expected to grow at a much faster rate.

Title 24 in California is at the forefront of establishing a national standard. By January 2014, this change in code will require automatic daylight harvesting controls be added to many commercial buildings. Additionally, occupancy sensing functionality will also be mandated for many applications. This change in code is the most significant driver in the market, as end-users tend not to adopt control technology improvement unless mandated.

Due to the increasing complexity of lighting control system specification, design, sales and installation, value-chain participants have had to adapt to the changing market dynamics. This circumstance has led to a number of end-users looking at alternative sales channels and other value-chain participants adjusting their business model appropriately. One such example is a change in the electrical distribution model. In recent years, many electrical distributors have established sales channels through energy audit teams, specifically targeting the retrofit marketplace. Some of these distributors include Graybar, Gexpro, Rexel, Facility Solutions Group (FSG), Crescent (CESCO), among others.

“The market is very much in a state of transition,” states principal analyst Anthony Miller. “I expect a great deal of consolidation and a change in the structure of how manufacturers sell to and support their customer base.”

Project specification can be influenced by a variety of different value-chain stakeholders. Lighting specification can occur by architects, lighting designers, electrical engineers, manufacturers, sales representatives, lighting agents or value added resellers (VARs).

The key participants in the distributed lighting control systems market include Acuity, Lutron, WattStopper, Encelium, Enlighted, Daintree, Redwood Systems, Digital Lumens, among others.

Quantum Electro Opto Systems Sdn. Bhd. (QEOS), a leading innovator in LED technology, announced today that it is entering the LED lighting and LED lighting systems business.  QEOS had previously commercialized its Tilted Charge Dynamics (TCD) device technology to produce the world’s fastest LED, which also featured lower cost, smaller size, and importantly, extremely low total power usage; thus providing a highly “Green Energy” product for the communications industry.  The company is now leveraging its R&D capability in materials and device design, optical lens technology and packaging, to bring forth new “Smart+” LED Lighting Systems, combining eco-friendly green technology with digitally-driven and Internet-enabled smart lighting.

Dr. Gabriel Walter, CEO of QEOS, said, “Through the use of advanced designs and packaging we can drive down cost and energy usage, while creating new uses of intelligent LED Lighting Systems.  It is our honor to enter the LED lighting systems market to create new innovations in applications on the 85th birthday of Nick Holonyak, Jr., a founder of QEOS and the inventor of the LED.  Product development for this market is a natural extension of our R&D.”

The worldwide LED lighting markets are expected to achieve significant growth as buildings, communities and governments convert to more cost effective systems. New QEOS Smart+ LED Lighting Systems continue the innovation by delivering better energy efficiency, lower heat emission, lower cost, lower environmental impact, and lower-maintenance systems; while leveraging digital control and Internet-enabled device integration and access.

Dr. Raymond Chin, Chairman of QEOS, said, “We foresee LED lighting systems rapidly becoming more integrated into the fabric of the Internet, and there is substantial room to create advanced products. At QEOS innovation is part of our DNA.   We also see integration between our Advanced Video Surveillance Security business and our new Smart+ LED Lighting Systems business,” he said. “Lighting Systems and Video Surveillance Security are complimentary to each other, and when integrated together can result in much better solutions for customers.”

Quantum Electro Opto Systems Sdn Bhd. is located in Melaka, Malaysia with operations in Cupertino, California in the heart of Silicon Valley. Its founders and management include Dr. Gabriel Walter and Dr. Raymond Chin, who are former students of Professor Holonyak; and also Professor Milton Feng, a co-inventor of the Transistor Laser.  QEOS has over 50 patents granted and pending

In either a cautious or a more aggressive scenario, LED applications will certainly be the key drivers for the bulk GaN market, according to Yole Développement.

There is no doubt that LED technology will take market share over the traditional lamp and tube business. The recent announcements from LED makers (> 150 lm/W now in production) are proving that the performance roadmap is in line with expectations: LED does as well and even better than traditional bulbs and tubes.

Native bulk GaN emerges as an alternative to sapphire or silicon, allowing further improvement of LED performance. Despite potential performance benefits for UHB-LEDs, massive adoption of GaN wafers remains hypothetical. Taking into account the historical price reductions of bulk GaN substrates, a base scenario outlines where the GaN on GaN LEDs will be limited only to niche markets.

“If the GaN industry succeeds in replying to the cost pressure from LED makers and the price of four inch GaN wafers falls below the breakeven price, a more significant adoption could be forecast. We see an about three times difference in terms of market volume for LED manufacturing between the two scenarios,” explains Dr Hong Lin, Market & Technology Analyst, Compound Semiconductors, at Yole Développement.

The demand of GaN substrates for LD applications will probably decrease below 20k TIE/yr threshold in the coming years.

Blu-ray applications now represent the largest market for blue LD applications. This market will increase in the short term with the arrival of the new generation game stations. However, Yole Développement believes that this growth will not persist, as more and more people will play games and watch movies online instead.

Despite the recent rapid development of blue and green laser diodes, Yole Développement sees two scenarios for the adoption of GaN based laser diodes for the emerging projector market. The price of LDs is the essential factor to consider.

Combining all applications, the demand for two inch GaN substrates will be more than two times higher in the aggressive scenario than in the base scenario. In the best case, the demand would keep relatively stable until 2020.

In R&D, non-polar and semi polar substrates have been proposed for LD manufacturing. In principle, the semi polar approach seems to be the most promising in terms of device performance. In practice, c-plane based devices still have better performance.

More than 85% commercial GaN wafers are produced by HVPE, dominated by Japanese companies.

Today, essentially all commercial GaN wafers are produced by HVPE, but the details of the growth process and separation techniques vary from company to company – for example, ammonothermal growth at Mitsubishi Chemical, and the new acidic ammonothermeral method at Soraa. Na-flux LPE growth seems promising, but Yole Développement’s analysts have not yet seen many GaN devices based on those substrates. It will take some time to convince the device producers.

Non-polar and semi polar substrates have attracted significant attention. However, the substrate size is still very small and unsuitable for mass production.

As of today, the GaN substrates market is currently heavily concentrated with 87 percent held by Japanese companies. Non-Japanese players are currently in small volume production or in R&D stage, too early to challenge the market leaders. Without exception, Japan will continue to dominate the Bulk/FS GaN market for the coming years.

LED GaN1

GaN substrates worldwide players (Yole Développement, November 2013)

Bulk GaN substrates for power electronics applications, a very challenging mission.

The GaN power device industry probably generated less than $2.5M in revenues in 2012. However, overall GaN activity has generated extra revenues as R&D contracts, qualification tests, and sampling for qualified customers was extremely buoyant. 16 out of 20 established power electronics companies are involved or will be involved in the GaN power industry.

Among the numerous substrates proposed for GaN power devices, bulk GaN solution is definitely beneficial to the device performance. However, Yole Développement remains quite pessimistic that bulk GaN could widely penetrate the power electronics segment unless 4” bulk GaN wafers can be in the $1,500 range by 2020.

The main reason is that, GaN power devices are positioned as a cost-effective solution, between incumbent Silicon and the ramping-up SiC technologies. If the $1,500 cost cannot be reached, then Yole Développement assumes no bulk GaN substrate will penetrate this market.

Growth of the LED industry has come initially from the small display application and has been driven forward by the LCD display application. In 2012, General lighting has surpassed all other applications, representing nearly 39 percent of total revenue of packaged LEDs. Indeed, the LED TV crisis of 2011 (following an overestimation of the market) had the benefit of decreasing LED prices and intensifying the competitive environment. As a matter of fact, LED-based lighting product prices have decreased more rapidly than expected, increasing the penetration rate of the technology.

Illustration_LED and lighting industries_YOLE DEVELOPPEMENT_September 2013

Click to view full screen.

Yole Développement estimates packaged LED will reach a market size of $13.9B in 2013 and will peak to $16B by 2018. Growth will be driven mainly by general lighting applications (45 percent to 65 percent of total revenue during this period), completed by display applications.

Other applications are still in motion

Regarding display and other applications, most products currently on the market integrate LED technology. Saturation mixed with strong price pressure and competition from OLED will make most of these markets decline starting from 2013 / 2014. Contrary to general lighting, overcapacity (inducing price pressure) has engendered a decrease in market size more rapidly than predicted.

This report presents all applications of LED and associated market metrics within the period 2008- 2020, detailing for each application: drivers & challenges, associated volume and market size (packaged LED, LED die surface), penetration rate of LEDs, and alternative technologies (…). For general lighting, a deeper analysis is developed with details on each market segment.

To keep the momentum, LED-based lighting product costs still need to be reduced

“Cost represents the main barrier LEDs must overcome to fully compete with incumbent technologies,” explained Pars Mukish, Market and technology analyst, LED at Yole Développement. “Since 2010, the price of packaged LEDs have sharply decreased, which has had the consequence of decreasing the price of LED-based lighting products.”

However, to maintain the growth trajectory, more efforts are needed in terms of price. LED still has some potential for cost reduction, but widespread adoption will also require manufacturers to play on all components of the system (drivers, heat sink, PCB…).

The report presents LED-based lighting product cost reduction opportunities, detailing: cost structure of packaged LED and LED lamp, key technologies and research areas.

Emerging substrates could change the rules in an industry dominated by sapphire

Sapphire (and SIC) remain the most widely used substrates for GaN epitaxy but many research teams are working on finding better alternatives in terms of performance and total cost of ownership. In that context, Si and GaN are the main new substrates developed in the LED industry:

Benefits of GaN-on-Si LEDs rely on decreasing manufacturing cost by using cheaper Silicon substrate but mainly by switching to an 8” substrate and using fully depreciated and highly automated CMOS fabs.

Benefits of GaN-on-GaN LEDs stem from the lower defect density in the epitaxial layers, allowing the device to be driven at higher current levels and to use a lower number of LED devices per system. 
However, several barriers need to be overcome:

GaN-on-Si LEDs are closer to GaN-on-Sapphire LED performance but increased manufacturing yields and full compatibility with CMOS fab still need to be achieved.

GaN-on-GaN LEDs suffer from GaN substrate availability and its cost. 
While GaN (GaN-on-GaN LEDs) holds some potential on specific high-end niches, we consider Silicon (GaN-on-Si LEDs) as the more serious contender as a potential alternative to the widespread use of Sapphire. But the success of GaN-on-Si LEDs will depend on the development of associated LEDs performance and development of manufacturing techniques.

 

Commercial uses for ultraviolet (UV) light are growing, and now a new kind of LED under development at The Ohio State University could lead to more portable and low-cost uses of the technology.

The patent-pending LED creates a more precise wavelength of UV light than today’s commercially available UV LEDs, and runs at much lower voltages and is more compact than other experimental methods for creating precise wavelength UV light.

The LED could lend itself to applications for chemical detection, disinfection, and UV curing. With significant further development, it might someday be able to provide a source for UV lasers for eye surgery and computer chip manufacture.

Read more: Imec and Veeco to collaborate on GaN-on-Si devices for LEDs and power electronics

In the journal Applied Physics Letters, Ohio State engineers describe how they created LEDs out of semiconductor nanowires which were doped with the rare earth element gadolinium.

The unique design enabled the engineers to excite the rare earth metal by passing electricity through the nanowires, said study co-author Roberto Myers, associate professor of materials science and engineering at Ohio State. But his team didn’t set out to make a UV LED.

“As far as we know, nobody had ever driven electrons through gadolinium inside an LED before,” Myers said. “We just wanted to see what would happen.”

When doctoral students Thomas Kent and Santino Carnevale started creating gadolinium-containing LEDs in the lab, they utilized another patent-pending technology they had helped develop—one for creating nanowire LEDs. On a silicon wafer, they tailor the wires’ composition to tune the polarization of the wires and the wavelength, or color, of the light emitted by the LED.

“We believe our device works at significantly less voltage precisely because of the LED structure.”

Gadolinium was chosen not to make a good UV LED, but to carry out a simple experiment probing the basic properties of a new material they were studying, called gadolinium nitride. During the course of that original experiment, Kent noticed that sharp emission lines characteristic of the element gadolinium could be controlled with electric current.

Different elements fluoresce at different wavelengths when they are excited, and gadolinium fluoresces most strongly at a very precise wavelength in the UV, outside of the range of human vision. The engineers found that the gadolinium-doped wires glowed brightly at several specific UV frequencies.

Read more: Demand for key raw material set to double as LED market booms

Exciting different materials to generate light is nothing new, but materials that glow in UV are harder to excite. The only other reported device which can electrically control gadolinium light emission requires more than 250 volts to operate. The Ohio State team showed that in a nanowire LED structure, the same effect can occur, but at far lower operating voltages: around 10 volts. High voltage devices are difficult to miniaturize, making the nanowire LEDs attractive for portable applications.

Read more: Device for capturing signatures uses tiny LEDs created with piezo-phototronic effect

“The other device needs high voltage because it pushes electrons through a vacuum and accelerates them, just like a cathode ray tube in an old-style TV. The high-energy electrons then slam into gadolinium atoms, which absorb the energy and re-emit it as light in the UV,” Myers explained.

“We believe our device works at significantly less voltage precisely because of the LED structure, where the gadolinium is placed in the center of the LED, exactly where electrons are losing their energy. The gadolinium atoms get excited and emit the same UV light, but the device only requires around 10 volts.”

Because the LED emits light at specific wavelengths, it could be useful for research spectroscopy applications that require a reference wavelength, and because it requires only 10 volts, it might be useful in portable devices.

The same technology could conceivably be used to make UV laser diodes. Currently high-powered gas lasers are used to produce a laser at UV wavelengths with applications from advanced electronics manufacturing to eye surgery. The so-called excimer lasers contain toxic gases and run on high voltages, so solid-state lasers are being explored as a lower power—and non-toxic—alternative.

As to cost, Kent pointed out that the team grows its LEDs on a standard silicon wafer, which is inexpensive and easily scaled up to use in industry.

“Using a cheap substrate is good; it balances the cost of manufacturing the nanowires,” he said.

The team is now working to maximize the efficiency of the UV LED, and the university’s Technology Commercialization and Knowledge Transfer Office will license the design—as well as the method for making specially doped nanowires—to industry.

This research was sponsored by the National Science Foundation (NSF) and Ohio State’s Center for Emergent Materials, one of a network of Materials Research Science and Engineering Centers funded by NSF.

The market for lighting controls in commercial buildings has entered a period of dramatic transformation, as the demand for both local controls, such as occupancy sensors and photosensors, and networked controls, rises and the adoption rate of light-emitting diode (LED) lighting systems begins to climb as well. According to a new report from Navigant Research, worldwide revenue from networked lighting controls will grow from $1.7 billion annually in 2013 to more than $5.3 billion by 2020.

“Building owners and managers, who are accustomed to the idea of centrally monitoring and managing their heating, ventilation, and air conditioning systems, are beginning to expect the same level of control from lighting systems,” says Jesse Foote, research analyst with Navigant Research. “To meet this growing demand, a number of different types of vendors – including pure-play startup companies and traditional lighting vendors – are moving aggressively into the lighting controls market.”

As falling prices for LEDs drive up adoption rates of LED lamps, the adoption of lighting controls will also accelerate, the study concludes. The semiconductor nature of LEDs makes them inherently controllable, with a high degree of dimmability, easy integration of controls with drivers, and instantaneous startup. In fact, many LED lamps are being sold with built-in controllability, whether or not there are plans to make use of those features.

The report, “Intelligent Lighting Controls for Commercial Buildings,” analyzes the global market for lighting controls for commercial buildings, including both new construction and retrofits. Sensors, ballasts, drivers, switches, relays, controllers, and communications technologies are examined, with a specific focus on networked lighting controls. The report details the market drivers for these technologies, as well as barriers to adoption, and includes profiles of select industry players. Market forecasts for unit shipments and revenue for each type of equipment, segmented by region and building type, extend through 2020. Forecasts are also broken out for control equipment in buildings with networked lighting controls, as well as for wireless lighting controls and LED drivers.

Researchers at the Georgia Institute of Technology want to put your signature up in lights – tiny lights, that is. Using thousands of nanometer-scale wires, the researchers have developed a sensor device that converts mechanical pressure – from a signature or a fingerprint – directly into light signals that can be captured and processed optically.

The sensor device could provide an artificial sense of touch, offering sensitivity comparable to that of the human skin. Beyond collecting signatures and fingerprints, the technique could also be used in biological imaging and micro-electromechanical (MEMS) systems. Ultimately, it could provide a new approach for human-machine interfaces.

Read more: Driven by Apple and Samsung, light sensors achieve double-digit growth

"You can write with your pen and the sensor will optically detect what you write at high resolution and with a very fast response rate," said Zhong Lin Wang, Regents’ professor and Hightower Chair in the School of Materials Science and Engineering at Georgia Tech. "This is a new principle for imaging force that uses parallel detection and avoids many of the complications of existing pressure sensors."

piezo LED

Individual zinc oxide (ZnO) nanowires that are part of the device operate as tiny light emitting diodes (LEDS) when placed under strain from the mechanical pressure, allowing the device to provide detailed information about the amount of pressure being applied. Known as piezo-phototronics, the technology – first described by Wang in 2009 – provides a new way to capture information about pressure applied at very high resolution: up to 6,300 dots per inch. The research was scheduled to be reported August 11 in the journal Nature Photonics. It was sponsored by the U.S. Department of Energy’s Office of Basic Energy Sciences, the National Science Foundation, and the Knowledge Innovation Program of the Chinese Academy of Sciences.

 Piezoelectric materials generate a charge polarization when they are placed under strain. The piezo-phototronic devices rely on that physical principle to tune and control the charge transport and recombination by the polarization charges present at the ends of individual nanowires. Grown atop a gallium nitride (GaN) film, the nanowires create pixeled light emitters whose output varies with the pressure, creating an electroluminescent signal that can be integrated with on-chip photonics for data transmission, processing and recording.

"When you have a zinc oxide nanowire under strain, you create a piezoelectric charge at both ends which forms a piezoelectric potential," Wang explained. "The presence of the potential distorts the band structure in the wire, causing electrons to remain in the p-n junction longer and enhancing the efficiency of the LED."

The efficiency increase in the LED is proportional to the strain created. Differences in the amount of strain applied translate to differences in light emitted from the root where the nanowires contact the gallium nitride film.

Read more: Student develops brighter, smarter and more efficient LEDs

To fabricate the devices, a low-temperature chemical growth technique is used to create a patterned array of zinc oxide nanowires on a gallium nitride thin film substrate with the c-axis pointing upward. The interfaces between the nanowires and the gallium nitride film form the bottom surfaces of the nanowires. After infiltrating the space between nanowires with a PMMA thermoplastic, oxygen plasma is used to etch away the PMMA enough to expose the tops of the zinc oxide nanowires.

piezo LED 2

A nickel-gold electrode is then used to form ohmic contact with the bottom gallium-nitride film, and a transparent indium-tin oxide (ITO) film is deposited on the top of the array to serve as a common electrode. When pressure is applied to the device through handwriting, nanowires are compressed along their axial directions, creating a negative piezo-potential, while uncompressed nanowires have no potential. The researchers have pressed letters into the top of the device, which produces a corresponding light output from the bottom of the device. This output – which can all be read at the same time – can be processed and transmitted. The ability to see all of the emitters simultaneously allows the device to provide a quick response. "The response time is fast, and you can read a million pixels in a microsecond," said Wang. "When the light emission is created, it can be detected immediately with the optical fiber."

The nanowires stop emitting light when the pressure is relieved. Switching from one mode to the other takes 90 milliseconds or less, Wang said.

The researchers studied the stability and reproducibility of the sensor array by examining the light emitting intensity of the individual pixels under strain for 25 repetitive on-off cycles. They found that the output fluctuation was approximately five percent, much smaller than the overall level of the signal. The robustness of more than 20,000 pixels was studied.

A spatial resolution of 2.7 microns was recorded from the device samples tested so far. Wang believes the resolution could be improved by reducing the diameter of the nanowires – allowing more nanowires to be grown – and by using a high-temperature fabrication process.

Displaybank’s recent market report on the cost competiveness of LED chips. This report conducts a thorough analysis on the supply price history, trends and forecast of main materials that compose packaged LEDs across the entire LED value chain. The key materials include sapphire ingot, substrate, LED chip (or die), frame (PCB, lead frame, ceramic), phosphor (YAG, silicate, nitride), and encapsulation. The supply price of the key materials used in the production of a packaged LED was assumed as the production cost. In addition, IHS has researched the average selling price (ASP) of a packaged LED every quarter since 2010, aside from this report.

In 2012, the 4-inch ingot/substrate lost its price premium compared to the 2-inch product, and the 6-inch product had to lower its margin because of excess supply in 2013. However, such drastic fluctuations in price are not expected to occur after 2014.

The LED chip suppliers have reaped great benefits with the falling production cost of 4-inch-substrate-based LED chips. However, it is expected that they will convert their production systems over to 6-inch or 8-inch substrates in the near future, with the falling prices of 6-inch substrates and enhanced yield rates. According to the report, the production cost competitiveness of LED chips produced on 6-inch substrates will outstrip that of 4-inch, by as early as 2015.

In addition, the report compares the production cost and selling price of packaged LEDs by application; analyzes the margin and cost structure; and forecasts for the cost and price until 2020.

Global demand for precursor, a material used in manufacturing of light-emitting diodes (LEDs), is set to more than double from 2012 to 2016, as the market for LED lighting booms, according to a new report entitled “Precursor for LED MOCVD–Market and Industry Analysis,” from Displaybank, now part of IHS.

The market for precursor used in the metal-organic chemical vapor deposition (MOCVD) manufacturing process for making LEDs will rise to 69 tons in 2016, up a notable 114 percent from 32 tons in 2012.

“The boom in the precursor market reflects the rising operating rate of MOCVD as the LED lighting market grows,” said Richard Son, senior LED analyst at IHS.

Precursor is a core material that ensures the optimal light efficiency for each LED epi layer. It is used in the MOCVD process, which is the most important process in manufacturing LED chips. Major precursors include trimethylgallium (TMGa), trimethylindium (TMIn), trimethyl aluminum (TMA), triethylgallium (TEGa) and C2Mg2. Among these, TMGa is the most widely used and commands about 94 percent of total demand.

Read more: Epi-wafer market to grow to $4 billion in 2020 as LED lighting zooms to $80 billion

Global shipments of MOCVD equipment are on the rise, with shipments expected to climb by 17 percent in 2013.

The largest buyers of MOCVD equipment—South Korea, Taiwan and China—account for about 80 percent of the global demand of precursors. China, which is generating the highest growth in installation of MOCVD equipment among the three countries, is expected to make up 45 percent of the global demand of precursors in 2016.

In the nascent stage of the LED market, Dow Chemical Co. was the unrivaled leader in the precursor market. However, with the recent growth in precursor demand, new players have been investing in R&D and manufacturing facilities while aggressively breaking into the market with low prices for similar-quality product. Such developments will intensify competition further among precursor makers.

Colors are playing an increasingly important role in the automotive sector. Consumers can not only choose the exterior color of the vehicle, you can also tailor the interior lighting to the customer’s individual taste. Thanks to the very wide blue color range of the new RGB MultiLED from Osram Opto Semiconductors, lighting designers have a virtually unlimited choice of colors for ambient lighting, including customer-specific colors. Color design now covers cluster lighting to an increasing extent, notably in combined instruments such as speedometers and RPM indicators, in infotainment and GPS displays, as backlighting for switches and in accent, ambient and trim lighting. Vehicles are fast becoming objects of individual design.

The main feature of the new MultiLED from Osram is a very broad blue color range with a wavelength of 447 to 476nm and high brightness. Deep saturated blue tones can now be produced thanks to the use of three LED chips in red, green and blue (RGB). Other properties of the MultiLED, such as its integrated ESD (electrostatic discharge) protective diode (2 kilovolts), its improved corrosion resistance, and its longtime market availability, make these LEDs ideal for use in automobiles. The MultiLED was developed specifically for applications in the automotive sector and meets all the requirements of an automotive certified component.

OSRAM multi-chip LED

All shades of blue

The new MultiLED consists of a red chip, a green chip and a blue chip (RGB LED). At 370 millicandelas (mcd), the blue is much brighter than in other multi-chip LEDs on the market. This brightness is a significant advantage because the sensitivity of the human eye causes the color blue to be perceived as darker than it actually is.

Read more: LED revenues grow even as prices fall through 2016

"The new LED can offset this darker perception so that customer brightness requirements can be met for all color ranges," said David Rousseau, LED Product Marketing Manager at Osram Opto Semiconductors. "What’s more, a short-wave blue color has a pleasant saturated appearance. We have now succeeded in implementing this color range in an RGB LED version."

The three independently controllable LED chips in blue, red and green in the MultiLED are available in different brightness groups thanks to finely defined grouping (known as binning). They can be individually combined to produce a large color spectrum. All three chip colors are the product of leading-edge technology: blue and green in UX:3 technology, red in the latest thin-film technology. The light is extracted from the chip with very high efficiency, resulting in high luminous intensity. In the upper blue wavelength range, for example, a level of up to 560 millicandelas is achieved at an operating current of 20 mA. Luminous intensity in candelas (cd) corresponds to luminous flux in lumens (lm) emitted by a light source in a particular solid angle. The typical thermal resistance between the chip and the solder point is 127 K/W for blue and green, and 96 K/W for red.