#Japan #Tokyo #semiconductor technology #Taiyo Holdings #FPIM Series

Introduction

On November 13, 2025, Taiyo Holdings Co., Ltd., based in Tokyo, made a significant announcement at the 14th IEEE CPMT Symposium Japan. The company introduced its new semiconductor packaging material, known as the FPIM (TM) Series. This innovative material is designed to enhance fine-pitch redistribution layers (RDLs) crucial for advanced semiconductor packaging.

RDL Technology

Redistribution layers are essential for creating efficient electrical connections in semiconductor structures. They enable the distribution of electrical wiring across the chip surface to meet the growing demands for higher precision and performance. Currently, the standard method for creating RDLs is the semi-additive process (SAP). However, with advancements in technology, the damascene process is gaining attention as a viable alternative for achieving finer wiring with line spacings of 1.6 micrometers or less.

Collaboration with imec

Taiyo Holdings has been collaborating with imec, a prominent semiconductor research institution, since October 2022. Together, they focused on developing the FPIM series, a negative-type photosensitive insulating material specifically designed for the damascene process. The joint research aims to push the boundaries of semiconductor packaging by facilitating finer wiring techniques, which are critical in future applications, especially in AI semiconductors.

Successful Demonstration

In a noteworthy achievement during the symposium, Taiyo Holdings showcased a three-layer RDL structure formed on a 12-inch wafer utilizing the FPIM material. The evaluations demonstrated that the material met the stringent requirements for fine dimensions. The results revealed that the first RDL layer achieved a critical dimension (CD) of 1.6 micrometers, with the via layer reaching a CD of 2.0 micrometers, and the second RDL layer also meeting the 1.6 micrometers target. These findings are significant as they approach the resolution limits of the utilized low NA stepper technology.

Electrical Performance

The electrical characteristics of the RDL, particularly for the first layer with a CD of 1.6 micrometers, yielded positive results regarding leakage current and resistance. Such favorable evaluations indicate that the FPIM series possesses not only high resolution but also excellent electrical properties suited for integration into the chemical mechanical planarization (CMP) process, further showcasing its reliability in advanced semiconductor manufacturing.

Future Prospects

Looking ahead, Taiyo Holdings aims to further innovate by achieving RDLs with wiring pitches of 500 nanometers or less. Ongoing research will continue to verify long-term electrical characteristics and reliability, ensuring the FPIM series contributes significantly to the evolving landscape of semiconductor packaging technology. In 2025, the company began shipping small quantities of this material for research and development purposes, marking an important step towards its broader application in the industry.

Conclusion

Through continuous collaboration and innovation, Taiyo Holdings is poised to enhance the semiconductor packaging field significantly. The launch of the FPIM series represents not only a technological milestone but also a commitment to advancing the future of semiconductor technology, with particular emphasis on boosting the performance of AI-enabled devices and applications. The collaboration with imec is expected to yield further breakthroughs in semiconductor materials, enhancing efficiency and performance in the technology sector.