Tatsuya Makino

Material technology for 2.5D/3D package

Packaging material is one of the key components for through-silicon via (TSV) 2.5D/3D package giving a strong impact on the higher density integration and its reliability. We have developed and evaluated our packaging materials by collaborating with 3D system integration program in Interuniversity microelectronics center (IMEC). In this paper, we report the assembly and reliability results on film type underfill, photosensitive dielectric for redistribution layer as well as stress buffer, and molding compound. In the case of using our film type underfill, five-chip stacked package with TSV and 20 μm pitch bumps was demonstrated with excellent electrical yield. Also photosensitive dielectric realizes redistribution layers with 3 μm resolution. Finally we integrated our film type underfill, dielectric and molding compound in the stacked package, passing reliability tests such as thermal cycling and pressure cooker test.

Photosensitive insulation coating for a copper redistribution layer process

Redistribution on a through-silicon via (TSV) with a copper interconnection and dielectric layer is one of the key components for a silicon-based interposer. In this paper, we report lithographic and mechanical performance for a positive-tone photosensitive insulation coating, CA6001B. Minimum resolution for CA6001B is 3 μm determined by electrical measurement with a test wafer having a copper redistribution and the patterned insulation layers. The CA6001B is one of the promising dielectric coatings for interposers possessing TSV and redistribution layer (RDL) structures.

Optical waveguide materials with high thermal reliability and their applications for high-density optical interconnections

This paper describes newly-developed optical waveguide materials and their future applications in optoelectronic circuit boards. The materials achieved low optical loss and high thermal reliability, as well as good flexibility. We fabricated both flexible and rigid optoelectronic circuit board prototypes using these newly-developed materials, and successfully demonstrated light signal transmission faster than 10 Gbps/ch.