Seoul Viosys Achieves High EQEs In Ultra-tiny Micro-LED Package

Seoul Viosys, a subsidiary of LED chip maker Seoul Semiconductor is poised to become a game changer in the global display industry.

The company said on August 19 that it has successfully developed blue and green micro-LEDs with a 1 μm diameter in a joint R&D project with Santa Barbara-based Solid State Lighting & Energy Electronics Center,

At the same time, the LED chip maker has successfully tackled tough technical challenges in mass-producing red LED chips with less than 70 μm diameter, opening up new market opportunities

Micro-LEDs are a new type of ultra-tiny LED chips, promising to replace LCDs, OLEDs and QLEDs in global display market, especially B2B applications like digital signages.

They boast of wider color gamut, high luminance, low power consumption, excellent stability, and long lifetime, as well as wide view angles, high dynamic range, high contrast, fast refresh rate, transparency, seamless connection, and sensor integration capability.

Yet, they still have more challenges than merits in commercializing, as their external quantum efficiencies, or EQEs are still lower, compared with conventional LEDs.

The most challenging technical hurdle is to miniaturize their footprints without compromising the EQEs.

Seoul Viosys starts mass-production of ultra-tiny, but highly quantum-efficient micro-LEDs

The EQEs is a measure of how bright a micro-LED chip is, referring to the ratio of the number of photons emitted by the LED versus the number of injected electrical charges

 For instance, conventional LEDs can reach external quantum efficiencies (EQEs) to 70%, while those of tiny micro LEDs less than 10µm are just in the neighborhood of 20&. Red LEDs are especially challenging with low EQEs and brittle features.

Seoul Viosys has tackled these challenges, opening the way to assemble 1um diameter-sized blue and green micro-LEDs and red micro-LEDs of 70um in diameter, but ultra-high EQEs in a single package.

Mass-production of this micro-LED package (Model No.: MC 04 and MC 02) has already begun, aiming to address smart phones, AR and VR markets.

By jerking up external quantum efficiency of the red micro-LEDs by 150%, Seoul Viosys has greatly improved the brightness of the MC04 and MC02 micro-LED package      

Seoul’s innovation doesn’t stop there. The company is gearing itself up to release 30μm one-pixel Micro LED products in the second half of 2021 and 10μm one-pixel Micro LED products in 2022.

Led by Shuji Nakamura, Nobel Laureate in physics and professor of University of California, thee Santa Barbara (UCSB)Solid State Lighting and Energy Electronics Center team has been working together with Seoul Viosys to commercialize ultra-small, but highly luminescent LED chips.        

Established in 2001, Seoul Viosys is the world’s largest UV LED chip maker, producing a wide range of LED products including micro-LED chips, UV LEDs, and V-LEDs.  The company is publicly listed in the tech-heavy KOSDAQ stock market, the Korean equivalent of the U.S, Nasdaq