Professor Sung-Hoon Kwon designed a new fabrication process for micro-LEDs, where simply placing it in water and shaking it completes the process. (Science Chosun, 2023.07.13)

July 28, 2023l Hit 441

Professor Sung-Hoon Kwon’s research team designed a new fabrication process involving fluidic self-assembly. The work, which was the culmination of 5 years of micro-LED mass production research with LG Electronics, was published on the Nature journal.

Professor Sung-Hoon Kwon of SNU Department of Electrical and Computer Engineering
/Photo provided by the Ministry of Science and ICT

Sung-Hoon Kwon and his research team have introduced a technology for stable mass production of micro-LEDs that leverages on fluidic self-assembly. The research was published in the international academic journal 'Nature' on the 12th (local time). Professor Chang-Soon Kim's team from the Organic Electronics and Nanophotonics Laboratory at SNU also participated in this study.

The advantage of micro-LEDs is that they do not suffer from the "burn-in" phenomenon, a critical drawback, found in OLEDs. Burn-in occurs when the components that make up the display reach the end of their lifespan, leaving residual images on the screen. OLEDs are made of organic materials sensitive to light and heat, and thus experience a decline in brightness and color reproduction as the usage time increases, making them susceptible to burn-in. On the other hand, micro-LEDs are made of durable inorganic materials and thus are much less prone to burn-in compared to OLEDs.

The process of creating fluidic self-assembled micro-LEDs involves soldering on the substrate, gently melting the solder in water in 88 degree Celsius, then placing the mixture, the assembly solution and micro-LED components into a container and shaking it. The components automatically move to their positions, resulting in the assembly of the LED.

To confirm the performance of the micro-LEDs, the research team created prototypes. They successfully assembled a blue LED panel with 20,000 micro-LEDs produced through fluidic self-assembly fabrication technology, and confirmed that the panel functioned without any error. The produced micro-LEDs were approximately 45 micrometers in length and had a thickness of 5 micrometers, making them 16 times thinner than the thickness of an average human hair, which is around 80 micrometers.

Professor Kwon commented, "The yield achieved in this research is a groundbreaking number in the research field of micro-LED mass production." He further commented that "Through more follow-up research, we will strive to reach the 'dream yield' of 99.999999%, which is the yield envisioned in the display industry." Professor Kwon's research team collaborated with LG Electronics for the past five years to develop this technology.

The blue display panel assembled using 20,000 micro-LEDs produced through fluidic self-assembly. The photo shows the panel in normal operation. / Photo provided by SNU

Source: https://ee.snu.ac.kr/community/news?bm=v&bbsidx=53764

Translated by: Do-Hyung Kim, English Editor of the Department of Electrical and Computer Engineering, kimdohyung@snu.ac.kr

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Professor Sung-Hoon Kwon designed a new fabrication process for micro-LEDs, where simply placing it in water and shaking it completes the process. (Science Chosun, 2023.07.13)