Future Advanced Package Solutions for HPC/AI Applications

The rapid growth of generative AI and large language models (LLMs) has intensified demands for higher bandwidth, lower latency, and improved power efficiency in AI and high-performance computing (HPC) systems. Advanced packaging has become a critical enabler, driving innovations in heterogeneous integration. Key technologies include 2.5D/3D stacking using thermal compression bonding (TCB) and hybrid bonding, large-area interposers (Si-based 2.5D and organic-based 2.3D), and panel-level packaging (PLP) for scalable integration. High-bandwidth memory (HBM) continues to evolve, enabling faster data access with improved thermal and electrical performance. Co-packaged optics (CPO) has emerged as a transformative solution to overcome electrical I/O limitations, particularly as bandwidth scaling reaches physical and power constraints. By integrating photonic engines closely with compute dies, CPO enables terabit-scale interconnects with significantly reduced power consumption and latency compared to traditional pluggable optics. This integration requires not only advanced packaging capabilities, such as high-precision alignment and thermal-mechanical reliability—challenges that are actively addressed through innovations in 3D and 2.5D stacking—but also optical design capabilities, including optical path optimization and low-loss optical coupling. This paper reviews the current landscape and technical challenges in advanced packaging, highlighting how 3D integration, HBM, and CPO areredefining system architecture. We emphasize the role of advanced packaging as a key enabler for next-generation AI compute engines, where performance, power, and scalability are increasingly determined at the package level.