26 , March
On March 19, according to South Korean media The Elec, LG Display (LGD) is developing defective pixel inspection and repair processes for Micro LED panels, aiming to address the yield and cost challenges commonly faced by the industry.
According to industry sources on March 17, LG Display has been participating in a national-level Micro LED inspection and repair R&D project led by the Ministry of Trade, Industry and Energy (MOTIE) of South Korea since April last year. The project is jointly promoted by the Ulsan National Institute of Science and Technology (UNIST), Korea Display Industry Association and related enterprises. As a core panel manufacturer, LG Display is mainly responsible for process verification and performance evaluation, conducting actual tests and verification especially for widely used small and medium‑size sizes such as 10.1‑inch and 15.6‑inch. The project adopts a division‑of‑labor collaboration model: equipment manufacturers and research institutes are responsible for the development of inspection and repair technologies, while LG Display verifies technical feasibility and mass‑production stability from the perspective of actual production.
Micro LED displays are fabricated by transferring and arranging hundreds of thousands to millions of micron-scale LED chips onto a substrate. Using inorganic light-emitting materials, they offer superior advantages over OLEDs in terms of brightness, lifespan, and energy efficiency, and are widely recognized as the next-generation mainstream display technology. However, as the chip size is only 5–100 micrometers, defective pixels are highly likely to occur during mass transfer and bonding processes. Even with a yield rate of 99.99%, high-resolution panels may still contain tens of thousands of dead pixels, a phenomenon particularly evident in medium-to-large size products such as 12.1-inch and 15.6-inch panels.
Current inspection technologies commonly used in the industry have obvious limitations. Traditional electroluminescence (EL) inspection requires physical contact, which poses a risk of chip damage. Although optical-based photoluminescence (PL) inspection enables non-contact operation, it lacks sufficient precision and cannot meet the requirements of high-end Micro LED panels. Therefore, an efficient process integrating inspection and repair has become the key to the large-scale mass production of Micro LED.
Industry insiders note that, due to the characteristics of the manufacturing process, defective pixels in Micro LED are almost unavoidable, and inspection and repair technologies directly determine product yield. To achieve true commercialization, stable technologies throughout the entire process—including transfer, bonding, inspection, and repair—must be ensured. Among these, inspection and repair are core processes that affect both yield rate and manufacturing cost. Industry experts point out that although breakthroughs in repair technology do not directly accelerate product launches, they can significantly reduce production costs by improving yield rates, laying the foundation for the commercialization and popularization of mainstream sizes such as 10.1-inch and 12.1-inch panels.
Notably, this R&D project is part of the “Inorganic Light Emitting Diode (iLED) Display Technology Development Ecosystem Construction Project”. This upper-level program was launched last year and will continue until 2032, with a total investment of 484 billion KRW, covering next-generation inorganic light-emitting technologies including Micro LED. The project includes sub-tasks such as “Development of Inspection and Repair Process Technologies for Chip-Replaceable Small-to-Medium Size Micro LED Display Panels” and “Development of Inspection and Repair Process Technologies for Non-Chip-Replaceable Panels”. Each sub-task has an implementation period of approximately 45 months and will continuously provide technical support for the mass production of small-to-medium size Micro LED panels.
