More efficient and constant display backlighting with Osram-LEDs

15,000 hours of constant output for portable device displays with MicroSideled 3806

Even at high temperatures and high currents the MicroSideled 3806 from Osram Opto Semiconductors ensures stable light conditions on the display. The brightness of this light emitting diode, which is available in white and blue, remains constant throughout its lifetime, and the color rendering leaves nothing to be desired. They also offer particularly impressive efficiency so these semiconductor light sources are ideal for 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. The MicroSideled 3806 has been designed specifically to meet these requirements. It is extremely 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 it does not simply go dark. At this time, half of the light emitting diodes will still provide 70 percent of their initial brightness (L70/ B50).

Impressive luminous efficacy and external quantum efficiency

The white version is a classic LED with chip and converter, achieving a high efficiency of 150 lumen/watt (lm/W). Matthias Winter, Marketing Director Consumer at Osram Opto Semiconductors mentions another benefit: “For white in particular we offer very fine binning so there is always a uniform color over the entire backlit surface.”

The efficiency of the blue MicroSideled is an impressive 55 percent, measured as the external quantum efficiency (EQE), in other words the ratio of the electrical power used to the emitted optical power. This LED is designed for special display technology that uses quantum dots (special nano particles) as conversion material. This conversion technology features a thin sheet with quantum dots (the quantum dot sheet) in the backlighting. This sheet is illuminated by the blue LEDs. This in turn leads to an extremely narrow-band emission spectrum which accurately hits the color filters of the backlighting unit. Light losses are therefore kept to a minimum and the colors are more vibrant. System efficiency with this conversion technology is 10 to 15 percent greater than with classic white LED solutions. Coverage of the color space is also 33 percent better than with classic white LED systems.

Both versions are compact, measuring only 3.8 x 1.0 x 0.6 mm (length x width x height), and have good thermal conductivity with a thermal resistance of 66 K/W.

“The new MicroSideled offers extraordinarily high efficiency, constant brightness and brilliant color rendering, irrespective of which technology is used to create white light” is how Matthias Winter sums it up.