San Jose, Calif. — OSRAM Opto Semiconductors Inc. has made significant improvements to its proprietary thin-film technology that have resulted in enhancements to the luminous efficacy and color palette of its Power TOPLED line of light-emitting diodes (LEDs) for automotive, signal and signage applications. The new Power TOPLED products are said to offer 150 percent greater efficiency and produce a wide variety of red and yellow tones. In addition, the new devices offer all the benefits of surface-mount technology in a very high brightness LED.
Improvements to the company's thin-film technology enable all generated light to emit through the top of the LED chip, which the company said results in higher luminous efficacy and red indium gallium aluminum phosphide (InGaAlP) LEDs that are bright enough for a wide range of applications including rear light clusters and indicators in automobiles and for display panels in traffic control systems.
"We've married our latest proprietary thin-film chip technology with our Power TOPLED package. This latest version is a more advanced semiconductor process that essentially removes the absorbing layer of the chip. In layman's terms this means the light that used to get caught in the chip and never escape now gets out and is redirected out to the top of the chip as useable light for LED users in their applications," said Jim Loeffler, senior product marketing manager for OSRAM Opto Semiconductor.
OSRAM's Power TOPLED product portfolio now includes yellow, orange, red and super-red versions ranging between 606 and 633 nanometers (nm). The luminous efficiency ratings are 38 lumens per watt (lm/W) for super-red, 49 lm/W for red, 69 lm/W for amber and orange, and 44 lm/W for yellow. At a 50 mA forward current, the luminous intensity of the LEDs is as follows:
- Super-red: 900-2240 millicandela (mcd)
- Red: 900-2240 or 1120-2800 mcd
- Amber: 1120-2800 or 1800-3550 mcd
- Orange: 1400-3550 mcd
- Yellow: 1400-3550 mcd
Key benefits
The new devices range anywhere from 50 to 70 percent brighter than previous generation parts which clearly opens up the door for new applications, said Loeffler. He expects that these new high brightness LEDs will find homes in automotive exterior lighting, lighting for trucking and emergency vehicles, traffic signals, signage and contour lighting on retail and commercial establishments, as well as other applications typically reserved for conventional light sources.
Achieving the levels of light output that these devices offer today has not been previously possible with LEDs using conventional surface-mount manufacturing, Loeffler said.
What this means is that designers can make their products brighter than they are today just by replacing the existing Power TOPLED; they can lower the cost of their product by using fewer LEDs because these new devices are brighter, or they can make their product more energy efficiency by using the same number of LEDs and driving them at a lower drive current, Loeffler explained.
Existing customers can replace their existing TOPLEDs with these brighter Power TOPLEDs without a major redesign, Loeffler said. In some cases, they will be able to drop in these new LEDs as direct replacements, but in other cases, they may have to change the polarity of their circuit board, but it's easy to achieve, he said.
Although there are devices available in the market that offer these brightness levels, they generally aren't in surface-mount type packages. Previously, if a designer wanted this brightness level, he had to make compromises on the LED design, package or the LED assembly techniques, Loeffler said. "Now you can have thin packages, small packages, low-cost and standard manufacturability that surface-mount technology allows with the high brightness output that a designer needs for some of these applications and that is really an industry first."
The company also plans to offer enhanced versions of its Advanced Power TOPLED, SIDELED, Golden DRAGON and miniaturized PointLED in 2006.
Packaged in a white PLCC-4 package, the Power TOPLEDs are priced at approximately $0.35 in sample and low-volume quantities. Delivery for sample quantities is one to two weeks. These devices are lead free and RoHS compliant.
OSRAM Opto Semiconductors, 1-888-446-7726, www.osram-os.com
Editor's note: For more information on automotive electronics, visit Automotive DesignLine.
