Osram Opto Semiconductors GmbH of Regensburg, Germany says that, even at high temperatures and high currents, its new MicroSideled 3806 ensures stable light conditions on the display. The brightness of the light-emitting diode, which is available in white and blue, remains constant throughout its lifetime. They also offer high efficiency, so the light sources suit portable devices such as tablets and smartphones. Multifunctional devices such as tablets, ultrabooks and even smartphones need high brightness levels and good color rendering without draining the batteries too quickly. Osram Opto says that the MicroSideled 3806 has been designed specifically to meet these requirements. It is very efficient in white and also in blue, offers constant brightness throughout its lifetime of 15,000 hours, and can withstand high temperatures and high currents. At the end of its rated life, half of the LEDs will still provide 70% of their initial brightness (L70/B50).
The white version is a classic LED with chip and converter, achieving high luminous efficiency of 150 lumen/watt (lm/W). "For white in particular we offer very fine binning, so there is always a uniform color over the entire backlit surface," says Matthias Winter, marketing director, consumer. The color temperature range is 2700-10,000K.
The blue MicroSideled has 55% external quantum efficiency (EQE, the ratio of the electrical power used to the optical power emitted). The LED is designed for display technology that uses quantum dots (nano-particles) in the conversion material. This conversion technology features a thin sheet containing quantum dots (a quantum dot sheet) in the backlighting. This sheet is illuminated by the blue LEDs. This in turn leads to a very narrow-band emission spectrum that accurately hits the color filters of the backlighting unit. Light losses are therefore kept to a minimum and the colors are more vibrant, says the firm. System efficiency is hence 10-15% greater than with classic white LED solutions, it is reckoned. Also, coverage of the color space is 33% better than with classic white LED systems.
Both versions are compact, measuring only 3.8mm by 1.0mm (by 0.6mm high), and have good thermal conductivity with a thermal resistance of 66K/W.
"The new MicroSideled offers extraordinarily high efficiency, constant brightness and brilliant color rendering, irrespective of which technology is used to create white light," summarizes Winter.
