Colors are playing an increasingly important role in the automotive sector. Now it's not only the exterior color of the vehicle that you can choose, you can also tailor the interior lighting to your individual taste. Thanks to the very wide blue color range of the new RGB MultiLED, lighting designers have a free 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 rev counters, in displays, as backlighting for switches and for ambient lighting. Vehicles are therefore becoming objects of individual design.
The main feature of the new MultiLED from Osram Opto Semiconductors is a very broad blue color range with a wavelength of up to 447 nanometers (nm) and high brightness. Deep saturated blue tones can now be produced to meet the demand of the market. This is thanks to the use of three LED chips in red, green and blue (RGB). Other properties of the MultiLED, such as its integrated ESD protective diode (electrostatic discharge), its improved corrosion resistance and its long market availability, make these LEDs ideal for use in automobiles.
All shades of blue
The new MultiLED consists of a red chip, a green chip and a blue chip (RGB LED). At 370 miilicandela (mcd) the blue is much brighter than in other multi-chip LEDs on the market. This brightness is a huge advantage because the specific sensitivity of the human eye means that the color blue is perceived to be darker than it actually is. "The new LED can offset this darker perception so that the brightness requirements of the applications can be met for all color ranges", said Stephan Pawlik, LED Automotive Marketing at Osram Opto Semiconductors. "What's more, a short-wave blue color has a pleasant saturated appearance. We have now succeeded to implement 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 state-of-the-art technology: Blue and green in UX:3 technology, red in the latest thin-film technology. The light is therefore extracted from the chip with high efficiency. This results in high luminous intensity. In the upper blue wavelength range, for example, a figure of up to 560 millicandelas is achieved at an operating current of 20 mA. Luminous intensity in candela (cd) corresponds to luminous flux in lumen (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.
The MultiLED was developed specifically for applications in the automotive sector and has been equipped with appropriate properties. It has been designed for long availability, has improved corrosion resistance and integrated ESD protective diodes (2 kilovolts). It therefore meets all the requirements of an automotive certified component.
The standard SMT package measures 3.3 x 3.0 x 1.8 mm and has the same footprint as the predecessor version.
|Component size||3.3 mm x 3.0 mm x 1.8 mm|
|Luminous intensity (typical)||750 mcd (red), 370 mcd (blue), 1630 mcd (green)|
|Conducting current (max.)||40 mA (red), 50 mA (blue, green)|
|Forward voltage (typical)||2.05 V (red), 3.2 V (blue, green)|