Seoul Viosys Co., Ltd. has begun mass production of WICOP 3, a package-free chip that emits white light without rare earths and can be as small as 10 micrometers (µm).
White LEDs have relied on rare earth materials such as yttrium aluminum garnet (YAG) layered onto a blue LED chip. Seoul Viosys says that while its earlier WICOP technology enabled smaller chips, white light still required a package containing rare earths, preventing white chips from going below 1,000 µm.
WICOP 3 is the third generation of the WICOP architecture, which eliminates the package. The chip produces white light from gallium nitride (GaN) alone and contains no rare earths, synthetic silicone resins, plastics or lead frames, according to the company. In its first mass production, a 25 µm by 10 µm chip produced 0.015 lumens, with chromaticity inside the CIE standard white region and luminous efficacy close to 100 lumens per watt (lm/W).
Seoul Viosys aims to reach 200 lm/W within two years. The company says WICOP 3 costs about half as much to make as a conventional white LED. It also describes possible applications for invisible micro opto-semiconductors embedded in wallpaper or window glass, which could provide lighting without fixtures.
The Seoul Group said it will first supply customers that have relied on its products and respected its intellectual property. It plans to develop new application markets with key customers.
