[News] LG Display Rumored to develop Micro LED Inspection and Repair Technologies

As per a report by The Elec on March 17, LG Display has been participating since April last year in a national R&D program on Micro LED inspection and repair, led by the Ministry of Trade, Industry and Energy.

The project is jointly carried out by Ulsan National Institute of Science and Technology (UNIST), the Korea Display Industry Association, Hubio, and Justem. As the panel maker, LG Display is responsible for process validation and performance evaluation. Under this framework, equipment vendors and research institutes develop inspection and repair technologies, while LG Display verifies them from the perspective of real-world manufacturing.

Micro LED displays are fabricated by transferring and arranging hundreds of thousands to millions of ultra-small LED chips onto a substrate. Unlike OLED, which relies on organic materials, Micro LED adopts inorganic emitters, offering superior brightness, lifetime, and energy efficiency, and is widely regarded as a next-generation display technology. However, due to process complexity, defective pixels—where some chips fail to function—are inevitable during mass production. With pixel sizes in the 5–100μm range, such defects are difficult to avoid.

As a result, inspection technologies for detecting defective pixels, along with repair processes to replace or fix them, are critical in Micro LED manufacturing. Conventional electroluminescence (EL) inspection requires physical contact, posing a risk of chip damage. Photoluminescence (PL) methods, based on optical techniques, enable non-contact inspection but are limited by lower accuracy.

Industry analysts note that integrating inspection and repair processes is becoming essential. Even assuming a yield rate of 99.99% for high-resolution panels, tens of thousands of defective pixels may still occur, meaning that the efficiency of inspection and repair processes directly impacts overall production efficiency.

A display industry source commented, “Due to the nature of the manufacturing process, defective pixels in Micro LED are unavoidable. Inspection and repair technologies play a crucial role in identifying and replacing these pixels, thereby ensuring yield.”

Stability across the entire process chain—including transfer, bonding, inspection, and repair—is required to enable the commercialization of Micro LED. In particular, inspection and repair technologies are viewed as key factors that simultaneously determine yield and manufacturing cost.

Another industry insider noted, “Rather than directly accelerating commercialization, repair technologies have a greater impact on reducing production costs, as improved yield ultimately lowers overall manufacturing expenses.”

Notably, a broader initiative—the “Ecosystem Development Project for Inorganic Light-Emitting (iLED) Display Technologies”—was launched last year and will run through 2032, with a total investment of KRW 484 billion. Inorganic light-emitting displays encompass next-generation emissive technologies, including Micro LED.

Subprojects under this initiative include “Development of inspection and repair process technologies for chip-replaceable small- and medium-sized Micro LED panels” and “Development of inspection and repair technologies for non-replaceable chip-based panels,” each with an implementation period of approximately 45 months.

(Photo credit: LG)