South Korea Excels at HBM Production, but Key Materials Are Japanese... 'Validation Barrier' Stalls Localization

Professor Yoon Changmin of Inha University: "Domestic Materials Companies Lack the Ability to Evaluate Materials in Actual Manufacturing Processes"
Japan Has Testing Facilities and a Joint Evaluation System; China Is Also a Packaging Powerhouse

South Korea has secured global competitiveness in producing high-bandwidth memory (HBM), but observers say it still relies heavily on Japanese companies for advanced packaging materials used to connect and protect semiconductor chips. Some domestic materials companies have developed materials but lack the equipment and data needed to verify whether they can be used in actual semiconductor manufacturing processes, making localization difficult, according to an analysis.

Professor Yoon Changmin of the Department of Polymer Science and Engineering at Inha University said on October 29 at the Press Day for the Korean Society of Industrial and Engineering Chemistry’s 2026 Fall Meeting, held at BEXCO in Busan: "In the HBM market, South Korean companies are essentially manufacturers. From the materials perspective, you could say they have nothing of their own."

Yoon Changmin, a professor in the Department of Polymer Science and Engineering at Inha University, presents at the press day for the Korean Industrial Chemistry Association's 2026 Fall Meeting at BEXCO in Busan on the 29th. Provided by the Korea Science Journalists Association.

Professor Yoon, who previously worked on semiconductor packaging and materials development at Samsung Electronics, compared the competitiveness of advanced packaging technologies and materials industries in South Korea and abroad.

HBM is high-performance memory that stacks multiple DRAM chips vertically to increase data processing speeds. It is a key component for improving the performance of artificial intelligence (AI) semiconductors. As more chips are stacked, technologies that ensure electrical connections, heat dissipation, and structural stability become increasingly important.

Asked which advanced packaging materials South Korea relies on most heavily from overseas and why localization is difficult, Professor Yoon cited underfill, a material for which Japanese companies hold a high market share. Underfill fills gaps between chips to protect joints and ensure structural stability.

Professor Yoon said Japanese companies maintain a high share of the HBM packaging materials market because of their ability to precisely combine the properties of multiple materials. He explained that it is necessary to ensure not only the performance of each material individually but also the stability of different materials when combined.

HBM uses multiple materials with different thermal expansion properties. As the temperature rises while a chip is operating, the materials expand at different rates, which can cause the package to bend or warp. Developing and validating materials is challenging because they must minimize this deformation while also ensuring insulation and heat dissipation performance.

Professor Yoon expects heat-dissipation materials to become even more important in next-generation HBM. He said technological development could move toward using alumina fillers, which have higher thermal conductivity than the silica fillers commonly used today.

"Japan Has Its Own Testing Facilities, but South Korea Lacks Evaluation Data"

Professor Yoon identified the domestic materials industry's biggest weakness as its ability to verify material performance in actual manufacturing processes. "Japanese companies don't just make materials; they have their own company-operated test beds for applying those materials to actual packaging," he said.

By contrast, some domestic materials companies have struggled to demonstrate their technological capabilities to customers because they have not secured enough evaluation data from actual processes.

A research image related to low-temperature hybrid bonding technology for next-generation semiconductor packaging, developed by a research team led by Professor Yun Changmin of Inha University. The technology bonds copper (Cu) interconnects to insulating layers and can be used in the stacking and interconnection processes of high-performance semiconductors. Courtesy of Professor Yun Changmin's laboratory.

Professor Yoon explained that domestic materials companies sometimes cannot provide data when semiconductor manufacturers request results from evaluations conducted in packaging processes.

Verifying advanced semiconductor materials requires expensive equipment and testing facilities. Japanese companies have built up relevant facilities and process experience over many years, while small and medium-sized materials companies in South Korea find it difficult to test their materials sufficiently in actual semiconductor manufacturing environments, according to the analysis.

"The biggest difference between Japan and South Korea is that Japanese companies have spent decades building these systems and have all the equipment and process facilities needed for evaluation," he emphasized.

He also drew attention to China's competitiveness in packaging technology. Professor Yoon explained that U.S. export restrictions on advanced semiconductor equipment have led China to invest actively in packaging technology instead of advanced manufacturing processes.

"China has considerable technological capabilities and market share in conventional packaging," he said. "But since there have been no examples of highly advanced packaging like HBM, some areas remain uncharted."

This content was produced with the assistance of AI translation services.