LightBundle™ — Using microLEDs to “move data” (Source: Avicena)

The performance of an interconnect (Source: Avicena)

Micro LED, which has been attracting attention as a next-generation display technology, is finding commercialization possibilities in new applications. Although its entry into the display market has been delayed due to low yields and complex manufacturing processes, the practicality of Micro LED is drawing attention again as demand for high-speed optical communication (Co-Packaged Optics, CPO) between AI semiconductors has recently increased. The CPO field is a field that matches well with the characteristics of Micro LED, which are small, high-speed, and low-power, and commercialization in this market is likely to act as a turning point that can accelerate its entry into the display market.

Micro LED is a display technology that combines the advantages of OLED and LCD to provide high brightness, long lifespan, no burn-in characteristics, and excellent color reproducibility. However, there are technical, manufacturing, and economic challenges that must be resolved for full-scale market expansion.

Technologically, millions of RGB chips of several μm in size must be precisely arranged and bonded, and the mass transfer process for this still has room for improvement in terms of speed, precision, and yield. In the bonding process, precision control technologies such as thermal stress and alignment errors need to be continuously advanced.

The manufacturing process also requires optimization. Since more than one pixel can affect the overall screen quality, high-precision inspection and advanced correction technologies are essential, and the current yield remains at around 10-30% based on the pilot line. The level of automation and the precision of inspection equipment are also major improvement tasks for securing future productivity.

In terms of economic feasibility, efficiency in yield and process cost structure is required. For example, Samsung Electronics’ 110-inch Micro-LED TV ‘The Wall’ is currently sold at around $150,000, and the material and equipment ecosystem also needs additional expansion to establish a full-scale mass production system.

Currently, Micro-LED is being introduced to the premium market centered on ultra-high-end TVs and large commercial signage, and expansion to various product groups such as AR and IT devices is expected in the future. Process standardization and supply chain establishment are gradually progressing across the industry, and this trend is expected to lead to a practical foundation for market expansion. Although various technology and process-related challenges still exist, they are recognized as step-by-step tasks that can be solved through improvement and evolution. In particular, the expansion of technology application in the non-display field is acting as a positive opportunity to verify the practicality and reliability of Micro-LED. AI servers and high-performance semiconductor systems require a high-speed, low-power optical communication environment, which is exactly aligned with the technical characteristics of Micro-LED. Existing electrical-based interconnects show limitations such as heat generation and bandwidth bottlenecks, and CPO technology, an optical signal-based communication structure, is being rapidly adopted to solve these problems.

Avicena, a US startup, is a leading company pioneering this field, and is implementing high-speed, low-power interconnects suitable for AI and HPC systems through its LightBundle™ solution, an optical communication technology based on Micro-LED. Avicena drives thousands of Micro-LED arrays in parallel to realize transmission speeds of tens to hundreds of Gbps, and demonstrates technological advantages in terms of low heat generation, low operating voltage, miniaturization, and parallelization compared to existing VCSELs. In addition, since it can be manufactured based on a CMOS process, it is also advantageous for integration with semiconductor packages.

Micro-LEDs for optical communication have simpler implementation conditions than those for displays. Since multi-color elements or high resolution are not required and the number of chips is limited to the thousands to tens of thousands, productization is possible even with a somewhat low yield. In fact, some companies including Avicena are entering the AI ​​server market with Micro-LED-based optical communication solutions, and in this market, actual communication performance and long-term reliability are key competitive factors rather than yield.

The expansion of demand in the AI ​​optical communication market is becoming an important catalyst for strengthening the mass production base of Micro-LED. Increased production, equipment investment, and expansion of the material supply chain can also lead to a virtuous cycle of yield improvement, process automation, and cost reduction in the display market. In fact, some equipment companies are developing integrated equipment that can simultaneously handle display and optical communication processes, and this is working as a positive signal for the entire industrial ecosystem.

Micro-LED is no longer a simple display technology. It is first proving its technical feasibility in practical applications such as AI optical communication and laying the foundation for commercialization, and this foundation is expected to be an important key to making full-scale entry into the display market a reality.

Changwook Han, Executive Vice President/Analyst at UBI Research (cwhan@ubiresearch.com)

UBI Research’s Micro Display Reports