ANSAN, South Korea: Seoul Semiconductor has announced a breakthrough in white LED technology with the development and mass production of a chip that produces white light without using rare earth materials.
The new technology, developed by Seoul Viosys Co., Ltd. (KOSDAQ: 092190), can produce chips as small as 10 micrometers (µm).
For nearly three decades, white LEDs have relied on rare earth materials such as yttrium aluminum garnet (YAG) layered onto a blue LED chip.
Seoul Viosys and its parent company, Seoul Semiconductor Co., Ltd. (KOSDAQ: 046890), said their latest WICOP 3 technology removes this dependence by enabling white light without rare earth elements (REEs).
Seoul Semiconductor and Seoul Viosys previously opened the micro LED market with WICOP, a chip architecture that eliminates the need for a package.
The companies have already developed and mass produced ultraviolet, blue, green, red and infrared LEDs below 100 µm using WICOP technology.
WICOP 3, the third generation of the technology, now extends that capability to white light without rare earth elements.
Seoul Semiconductor Targets White LED Market
White LEDs account for roughly $10 billion of the $15 billion global packaged LED market. Seoul Semiconductor said WICOP 3 can replace conventional white LEDs with a technology that does not use rare earth materials.
The company said WICOP 3 is the world’s first white opto-semiconductor to achieve white light in a micro LED smaller than 100 µm. At this size, the chip is invisible to the naked eye.
WICOP 3 uses neither rare earths nor a package. Rare earths are a major source of environmental pollution, while conventional LEDs use synthetic silicone resins, plastics and lead frames.
According to Seoul Semiconductor, WICOP 3 contains none of these materials and costs about half as much to manufacture as a conventional white LED.
Seoul Semiconductor Sees New Applications for Micro White LEDs
The company believes the miniaturisation of opto-semiconductors could create new markets in the same way that miniaturised transistors replaced vacuum tubes and expanded the electronics industry.
WICOP 3 generates white light from gallium nitride (GaN) alone. GaN is a natural material, and the chip contains no plastics, silicone or other synthetic organic materials. The company said this makes the chip virtually permanent, with the potential to last for decades.
In lighting applications, invisible micro opto-semiconductors could be embedded into wallpaper or window glass, allowing spaces to be illuminated without conventional fixtures.
The technology could also eliminate the need to replace bulbs and reduce the cost associated with lighting fixtures.
Seoul Semiconductor expects this to create a new market tens of times larger than today’s $10 billion white LED market.
WICOP 3 Performance
During its first mass production, a micro LED chip measuring just 25 µm by 10 µm produced 0.015 lumens of white light. Its chromaticity falls within the CIE standard white region.
The luminous efficacy of WICOP 3 is already close to 100 lumens per watt (lm/W), while Seoul Semiconductor aims to reach 200 lm/W within two years.
By comparison, a conventional 1,000 µm by 1,000 µm chip achieves 50 lumens.
Technical Significance of Seoul Semiconductor’s WICOP 3
Until now, WICOP technology could make LED chips smaller, but producing white light still required a package containing rare earth materials.
As a result, white chips could not be reduced below 1,000 µm, limiting further cost reductions.
White micro LEDs below 100 µm, or 0.1 mm, were also out of reach.
The removal of rare earth materials changes this limitation. WICOP 3 enables white light to be produced in both large chips measuring 1,000 µm and above and micro LEDs below 100 µm.
Seoul Semiconductor compares the development with the 1948 transition at Bell Laboratories in the United States from vacuum tubes to transistors.
The company said Seoul Semiconductor and Seoul Viosys have similarly moved beyond LEDs designed only to be seen, developing chips that are too small to see while emitting red, green, blue, infrared, ultraviolet and now white light.
The development expands the application potential of opto-semiconductors across areas including augmented reality (AR) and AI communications.
Seoul Semiconductor also said some products marketed as “flip chip” LEDs replicate WICOP’s patented technology. The company continues to protect its intellectual property worldwide.
Development Background and Evolution
Since the 2010s, more than 10 major Korean groups and over 300 Chinese companies have entered the LED market, intensifying price competition.
Founder Chung Hoon Lee, who studied physics, concluded that the company needed strategic breakthrough technology to survive and grow.
Seoul Semiconductor has since invested about $100 million a year in R&D and new inventions, including during years when the business was not profitable.
Silicon and opto-semiconductors are both made of soft materials that are vulnerable to dust and moisture. For that reason, both have traditionally been packaged for 60 years.
WICOP: First Generation
WICOP began with a question from Lee: “Why do semiconductors have to be packaged?”
After years of research, Seoul Semiconductor developed WICOP in 2018 and brought it into high-volume production. The company said it was the first chip in semiconductor history that requires no package.
Silicon semiconductors evolved from vacuum tubes to transistors and then to integrated circuits containing tens or hundreds of transistors.
Seoul Semiconductor believed WICOP could drive a similar evolution in opto-semiconductors and enable invisible micro LEDs below 100 µm.
The company has also conducted joint R&D with the University of California, Santa Barbara (UCSB) for 20 years. This work has produced devices on the 1 µm scale.
WICOP 2: Second Generation
LEDs historically required lenses to control the direction of light. Lee questioned this requirement as well, asking: “Why must we use a lens?”
He also asked, “Why must semiconductors operate only at 3 volts when household power is 110 or 220 volts?”
These questions led to WICOP 2, which directs light without a lens and operates at higher voltages of 12 or 24 volts.
Electric and hybrid vehicles operate on high-voltage batteries. In these vehicles, high-voltage opto-semiconductors can reduce power consumption by 20%.
WICOP 2 is now supplied to global customers including Tesla.
WICOP 3: Third Generation
The third generation of the technology emerged from another question: “Why must white light require rare earths?”
“We have now successfully developed WICOP 3, which produces white light, and have begun mass production,” said Lee, founder of Seoul Semiconductor.
Seoul Semiconductor’s Future Plans
The Seoul Group comprises Seoul Semiconductor and Seoul Viosys. The group will start mass production of WICOP 3 in the fourth quarter.
The companies will initially supply customers that have respected their intellectual property and relied on their products.
WICOP 3 produces white light without rare earth materials and is designed to provide a semipermanent white light source even at invisible sizes of 100 µm or less.
The group said it will continue to follow its “Keeping Principle” of never competing with its customers. Instead, it plans to open new application markets together with key customers.
Seoul Semiconductor Seeks Micro LED Supply Chain Partners
Seoul Viosys, an affiliate of Seoul Semiconductor, uses WICOP technology to produce micro opto-semiconductors below 100 µm.
Micro LEDs built on WICOP can now carry high volumes of AI data over distances ranging from under 1 cm to tens of meters.
Over short distances, data has traditionally travelled through copper wire as electrons. According to the company, electrons have mass, and the increasing data loads of the AI era can cause copper links to slow down, generate heat and consume significantly more power.
The company instead uses light to transmit data. Photons have no mass.
Seoul Viosys arranges 1,000 WICOP chips of about 10 µm each in a grid within 1 square millimeter or less. The company said this array can transmit data 10 times faster while using one tenth of the power.
Market research firms including Omdia forecast that this technology, together with AR, will create a new $60 billion market within five years. The company said this is equivalent to half of today’s DRAM memory market.
Lee said the company intends to use WICOP 1, WICOP 2 and WICOP 3 to help people around the world live better lives through AR glasses and AI data communications.
These technologies operate at invisible sizes of 10 µm or less. Seoul Viosys and Seoul Semiconductor are therefore seeking trusted upstream and downstream micro LED supply chain partners in AR displays and AI transmitters to build the new $60 billion market together.
