Technology | Jul 28, 2010

Compact 72-W Neutral White and 18-W Warm White LED Emitter with Record Lumen Efficiency

Optoelectronics Packaging & Materials Labs at the University of California developed a multi-chip integrated compact white LED single emitter with an import power of 72,84W, producing a total of 6543 lm at a CCT of 4455K that has reached a record lumen efficiency of 89,8 lm/W, and a multi-chip integrated warm white LED compact single emitter with an input power of 18,62W, producing a total of 1444lm at a CRI of 91,3 and a CCT of 3928K that has reached a record lumen efficiency of 77,4lm/W, according to the reports issued by the US National Institute of Standards and Technology on December 8, 2008.

This breakthrough results from the combination of innovations in the package design, the packaging process development, the white LED phosphors  as well as materials processing optimization, and no special prototype  blue LED chip is used, thus the innovative warm white LED product is ready for mass production.Moreover,  this breakthrough results from the combination of innovations in the package design, the packaging process development, the white LED phosphors as well as packaging materials processing optimization, and no special prototype  blue LED chip is used, thus the innovative neutral white LED product is ready for mass production.

72W Multi-Chip LED:
The multi-chip integrated compact white LED single emitter with an import power of 72,84W, producing a total of 6543 lm at a CCT of 4455K, developed by the Optoelectronics Packaging & Materials Labs at the University of California, Irvine, has reached a record lumen efficiency of 89,8 lm/W, according to the report issued by  the US National Institute of Standards and Technology.   
      
The measurement is performed after a thermal equilibrium being reached between the emitter and  its  heat sink at a steady-state temperature of 37°C. Thus, the efficiency is estimated as high as 95lm/W, if the LED junction temperature is kept at 25°C, which is normal industrial standard LED junction temperature in reporting the lumen measurement (which can be done by the so-called instantaneous measurement).   
        
The blue LED chips used for this emitter are available from open market, and the optical power for each bare die is about 260mW. However, the optical output of a bare blue chip is now as high as 571mW, according to a major LED chip producer. Thus,  if those 571-mW blue chips are used for the present innovative emitter,  the lumen output could be as high as  197lm/W.

18W Multi-Chip LED:           
The multi-chip integrated warm white LED  compact single emitter with an input power of 18.62W, producing a total of 1444lm at a CRI of 91.3 and a CCT of 3928K, developed by the Optoelectronics Packaging & Materials Labs at the University of California, Irvine, has reached a record lumen efficiency of 77,4lm/W, according to the measurement performed  by  the US National Institute of Standards and Technology.

The measurement is conducted after a thermal equilibrium being reached between  the emitter and  its  heat sink with a steady-state temperature of 37°C. Thus, the lumen efficiency is estimated as high as 82lm/W, if the LED junction temperature is kept at 25°C, which is normal industrial standard LED junction temperature in reporting the lumen measurement (which can be done by the so-called instantaneous measurement).   

The blue LED chips used for this emitter are available from open market, and the optical power for each bare die is about 260mW@350mA. However, the optical output of a bare blue chip is now as high as 571mW@350mA, according to a major LED chip producer. Thus,  if the present innovative packaging technology and white LED technologies are applied to those 571-mW@350mA blue chips,  the lumen output could be as high as 170lm/W.

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