Micro LEDs

Korean researchers at the Korea Institute of Machinery and Materials are checking samples of micro LED displays made with roll to roll transfer process equipment.

A mass production technology of micro LEDs, which are attracting attention as a next generation display after organic light emitting diodes (OLEDs), was developed by Korean researchers.

The Korea Institute of Machinery and Materials (KIMM) under the Ministry of Science, ICT and Future Planning announced on July 24 that the institute developed technology of manufacturing micro-LED (LED) display using 'roll transfer process' for the first time in the world.

Using a roll to roll transfer process, the Nano Applied Mechanics Team at the institute developed technology to produce 'micro LED displays', which have luminous efficacy three times higher and a 50% reduction of power consumption.

Using this research result, it will be possible to manufacture micro LED displays, which are attracting attention as next generation displays such as transparent displays with high mechanical reliability and can be changed freely, 10,000 times faster than conventional LED displays.

The roll to roll transfer process is a technology whose patent belong to the Korea Institute of Machinery and Materials. The TFT element is lifted and put on the desired substrate like putting ink on a roll, and the LED element is lifted up and placed on the substrate on which the TFT element is placed, completing an active matrix type micro LED display of a structure in which the two elements are combined.

Production speeds have been dramatically improved as production steps have been cut down. Current die bonder equipment, which makes conventional LED displays, can mount 1 to 10 LEDs on a substrate per second but through roll transfer technology more than 10,000 LEDs can be transferred per second. It takes more than 30 days to produce a full-HD 2-megapixel 100-inch digital signage via the current method, but the roll transfer process can finish the process within an hour and substantially slash process cost.

According to market research firm Market and Market, the micro LED market is expected to grow at a CAGR of 54.7% from US$ 250 million in 2017 to US$ 19.92 billion in 2025. The display sector is expected to account for 98% of the total micro LED market in 2025.