Taiyo Holdings Achieves 700-nm RDL Formation for Advanced Packaging

Taiyo Holdings Co., Ltd. has announced a major advancement in semiconductor packaging technology with its next-generation FPIM Series, a fine-pitch redistribution layer (RDL) material designed for advanced packaging applications. The company presented the latest research results on September 10, 2026, at the 11th IEEE Electronics System-Integration Technology Conference (IEEE ESTC 2026) in Helsinki, Finland.

The research was conducted jointly with imec, a leading global semiconductor research and innovation center. Taiyo Holdings developed the FPIM Series as a negative-tone i-line photosensitive insulating material intended for fine-pitch RDL formation using a dual damascene process. RDL technology plays an important role in advanced semiconductor packages by creating efficient electrical connections between different components and enabling increasingly compact interconnect structures.

Semiconductor manufacturers have traditionally relied heavily on the semi-additive process (SAP) for RDL manufacturing. However, as chip architectures continue to demand finer wiring pitches, the dual damascene process is expected to become increasingly important. According to imec, this approach is particularly relevant for interconnect pitches of approximately 1.6 micrometers or below.

Taiyo Holdings began collaborating with imec in October 2022 to develop materials capable of meeting these increasingly demanding requirements. Their joint progress was demonstrated in November 2025, when the companies reported successful formation of a three-layer RDL structure with a critical dimension (CD) of 1.6 micrometers on 12-inch wafers.

The latest research marks another significant step forward. Using the FPIM Series, the partners successfully produced a three-layer RDL structure on 12-inch wafers with a 700-nanometer CD for both interconnects and vias. The 700-nm metal 1 (M1) layer also showed favorable electrical performance, including low leakage current and suitable resistance characteristics.

The evaluation further confirmed that the FPIM Series combines high resolution with strong electrical characteristics and compatibility with chemical mechanical polishing (CMP) processes. These capabilities could support the development of submicron-class RDL design rules for future advanced semiconductor packages.

Taiyo Holdings plans to continue improving the technology, with a target of achieving RDL structures featuring CDs of 500 nm or less on wafers. The company will also conduct further evaluations of long-term electrical performance and reliability. Small-volume samples of the FPIM Series have already been supplied for research and development applications since 2025.

Chemical Commodity Price Impact

Taiyo Holdings’ FPIM Series could strengthen demand for advanced semiconductor-packaging materials as AI processors, high-performance computing, and heterogeneous integration require increasingly fine RDL structures. Achieving 700-nm CD demonstrates the material’s commercial potential and could support future adoption in high-end packaging. Further progress toward 500 nm may increase demand for photosensitive insulating materials, specialty polymers, resins, solvents, and associated electronic chemicals. For ChemAnalyst-tracked commodities, the immediate price impact is likely limited because R&D volumes remain small. However, successful commercialization could gradually lift demand and provide upward price support for high-purity semiconductor-grade chemicals and specialty materials, particularly as advanced packaging capacity expands globally.