Osram Opto Semiconductors GmbH of Regensurg, Germany has introduced what it claims is the first compact laser multi-chip package. The new PLPM4 450 module can pack up to 20 blue laser chips into a single butterfly package for projection applications.
Picture: The PLPM4 450, which provides blue light output of 50W.
Blue laser diodes in combination with a converter wheel (which converts part of the blue light into the two primary colors of red and green) are used as the light source for laser projectors. Up to now, to achieve sufficient brightness for professional applications, more than 20 individual laser diodes had to be combined.
Osram Opto says that, instead of taking the laborious approach and constructing a light source from individual laser diodes, in order to achieve high optical output in the PLPM4 450 it has optimized the chip parameters to double the single-chip output from 1.6W to 3.2W and also improved the thermal resistance of the module.
The PLPM4 450's 25.5mm by 35mm package accommodates four copper bars with up to five blue laser chips emitting at wavelengths of 440-460nm (with an emission surface of 16mm x 16.5mm) connected in series and operated at a current of 2.3A each. The multi-chip module can hence offer overall light output of 50W (at a package temperature of 50°C) from a typical electrical input of 165W, achieving efficiency of 30%.
Professional laser projectors can hence achieve brightness of more than 2000 lumen with only one packaged component. If several modules are installed in a projector, brightness levels far in excess of 5000 lumen are then possible (e.g. for devices in large conference rooms). Also, lifetime (until a 50% reduction in light) is up to 20,000 hours (depending on ambient conditions).
Osram Opto also says that, due to the special design and the improved optical output power of the individual chip, the price per optical watt can be reduced significantly. Another price benefit comes from the greatly reduced production costs – installation and alignment of a multi-chip package involve less time and lower costs than for a large number of individual metal can packages. The light from all the laser chips can therefore be collimated with a single lens array. "The innovative package simplifies the integration of laser technology in projectors considerably, enabling a breakthrough in the projection market," reckons marketing manager Stephan Haneder.
Volume production of the PLPM4 450 will start at the end of 2014. Samples will be available in the summer. The Osram Specialty Lighting business unit will also be integrating the multi-chip package in a new generation of phaser light modules for projection applications (where 'phaser' is a hybrid of 'phosphor' and 'laser'). Phaser light modules based on the multi-chip package will feature a particularly compact design and be capable of being used in combination, making them easy to integrate into existing projector architectures, says the firm.
