3D-MiM (MUST-in-MUST) Technology for Advanced System Integration

An advanced 3D Multi-stack (MUST) system integration technology, 3D MUST-in-MUST (3D-MiM) fan out package, has been developed as next generation wafer-level fan-out package technology. 3D-MiM technology utilizes a more simplified architecture which eliminates BGAs between packages for system-level performance, power and form-factor (PPA) purpose. This technology also makes use of a modularized approach for both design and integration flow to improve design flexibility and integration efficiency. Known-good pre-stacked memory cube and/or logic-memory cubes are fabricated by leveraging the established integrated fan-out technology platform (InFO) in tools, materials, design rules, and processes to shorten development cycle time and achieve cost effectiveness. Two 3D-MiM fan-out examples are presented in this paper. The first 3D-MiM package integrates a SoC with 16 memory chips in a 15 × 15 mm² footprint with 0.5 mm package height (final BGA included) for mobile application. The other 3D-MiM package integrates 8 SoCs with 32 memory chips in a 43 × 28 mm² footprint to mimic a system integration of multiple logic cores and multiple memory chips for HPC applications.