Fine-Pitch RDL with High Reliability Formed on Glass for Heterogeneous Integration

As AI cloud systems and high-speed data transfer systems are expected to become more advanced, mass-produced, and high-speed in the future, chiplet-compatible interposers are attracting attention as semiconductor mounting packages required for AI data servers. In this paper, we report on the development of RDL(Redistribution Layer) interposer suitable for high density, fine wiring, and high-speed transmission, as well as on the formation technology of fine wiring at 2-μm pitch, protective film formation technology to ensure reliability, and demonstration results in a 300 x 400 mm size to accommodate the increase in chip size (13 cm²). Furthermore, we conducted electromigration tests on our proposed inorganic dielectric-coated wiring (wiring widths of 1 μm and 2 μm) and demonstrated that it exhibits superior electromigration result compared to conventional wiring.