Goldeneye targets simpler LED chips
LEDs manufactured using just epitaxy will be able to provide illumination at a fraction of the cost of their competitors, thanks to the simple process used to make them.
That s the word coming out of Carlsbad, California, where Goldeneye, Inc. is touting its EpiChip, ahead of commercial introduction in the fall of 2008.
“Based on improved efficiencies, a reduced number of process steps and associated yield losses, the cost of manufacture is significantly less than conventional methods,” the company told compoundsemiconductor.net.
“Our intention is to use this technology in the design and fabrication of complete packaged light sources, not the sale of bare die,” it added.
The general lighting market will benefit from the first packages featuring these die, which promise improved extraction efficiencies and thermal management.
To date Goldeneye has made blue and green GaN EpiChips, with high-quality, robust, epilayers ranging from 10 to 50 µm thick. Driving currents are better spread across these thick layers than in thinner LEDs and the chip's contacts are better separated, making packaging more straightforward.
Typical measured output for one of Goldeneye s 200 x 200 µm 520 nm EpiChips is 5 mW at 20 mA driving current. The company has also made EpiChips up to 1 mm2 in area, which attain a similar output at 500 mA to the 200 x 200 µm chips at 20 mA, it says.
EpiChips were originally developed to go into Goldeneye's light recycling systems - reflective cavities where the brightness of outputs from the similarly reflective LEDs they accomodate are enhanced. However, now the company has patented its “epi-only” approach for a wider range of applications.
Although Goldeneye is reluctant to release details about how and where its thick epilayer LEDs are made, its patents suggest that HVPE is used. Otherwise, the company says it outsources to an “ensemble of strategic partners, contract manufacturers, and primary vendors”.
