Taiyo Holdings Unveils FPIM Series for Advanced Semiconductor Packaging

Taiyo Holdings, a Tokyo-based company, has unveiled a groundbreaking next-generation semiconductor-packaging material called the FPIM Series. The material, presented at the 11th IEEE Electronics System-Integration Technology Conference (IEEE ESTC 2026) in Helsinki, Finland, marks a significant step forward in the field of advanced semiconductor packaging.

The FPIM Series is a fine-pitch RDL (redistribution layer) negative-tone i-line photosensitive insulating material designed for dual damascene processes. This innovation aims to enhance the efficiency of electrical connections in semiconductor packaging, a critical component in the development of advanced packaging technologies.

In a joint research effort with imec, one of the world's largest semiconductor research institutes, Taiyo Holdings achieved a notable milestone. The collaboration resulted in the successful formation of a three-layer RDL structure with a critical dimension (CD) of 700 nm on 12-inch wafers. This breakthrough is particularly significant as it paves the way for submicron-class RDL design rules, which are essential for the future of advanced packaging.

The research, presented at the MIP 1: Dielectric and Glass Materials for Advanced Substrates session of the IEEE ESTC 2026, demonstrated that the FPIM Series material can achieve a 700-nm CD for both interconnects and vias. The material also showed favorable electrical characteristics, including low leakage current and resistance, which are crucial for the performance of next-generation AI semiconductors.

Imec and Taiyo Holdings began their joint research in October 2022, with the aim of developing materials suitable for the dual damascene process. Their efforts led to the successful formation of a three-layer RDL structure with a CD of 1.6 micrometers and a via CD of 2 micrometers on 12-inch wafers in November 2025. This achievement underscores the material's potential for fine-pitch wiring, which is essential for advancing semiconductor packaging technology.

According to Taiyo Holdings, the FPIM Series material is compatible with the chemical mechanical planarization (CMP) process, ensuring high-resolution performance. The company is now focused on achieving even finer pitch CD formation, aiming for a CD of 500 nm or less on wafers. This ongoing research will be crucial in further enhancing the performance and reliability of semiconductor packaging materials.

Taiyo Holdings has already begun shipping small-volume samples of the FPIM Series for R&D applications, signaling its commitment to the rapid advancement of semiconductor packaging technology. The material's development is part of the company's broader strategy to contribute to the growth of the semiconductor packaging field, enabling the continued evolution of advanced packaging solutions.

In the coming years, the FPIM Series material is expected to play a pivotal role in the development of next-generation semiconductor packaging technologies, driving innovation and efficiency in the industry. As Taiyo Holdings continues its research and development efforts, the semiconductor packaging landscape is poised for significant transformation, with the FPIM Series at the forefront of this change.