Advanced Packaging – A must for the next-gen AI and HPC Hardware and not only!

This article explores the growing importance of advanced packaging (AP) technologies for enabling next-generation AI and high-performance computing (HPC) hardware. It focuses on how these technologies, including chiplet-based architectures, interposers, fan-out packaging, and hybrid bonding, are essential to meet the rising demands of computing density, memory bandwidth, energy efficiency, and cost.

Key points from the paper include:

1. AI and HPC Demand: The increasing complexity of AI workloads, such as large language models (LLMs), has put pressure on traditional semiconductor architectures. The performance gap between processing power and memory bandwidth, referred to as the "memory wall," has become a bottleneck, making advanced packaging technologies critical for continued progress in AI and HPC.

2. Advanced Packaging Solutions:

• 2.5D/3D Packaging: These technologies integrate multiple dies on a single substrate, enabling more efficient communication between chiplets. The paper discusses how 2.5D/3D packaging addresses the limitations of traditional designs, such as power efficiency and bandwidth, by using interposers and TSVs (Through-Silicon Vias).

• Chiplets and Modular Architectures: Chiplets—discrete dies integrated into a single package—are highlighted as a key design philosophy for AI chips. They offer benefits such as higher yield, reusability, and the ability to mix and match process nodes, making them more cost-effective compared to monolithic chips.

• Fan-Out Wafer-Level Packaging (FO-WLP): This technique is increasingly used in AI and HPC applications due to its ability to integrate multiple chips on a single package. It provides low-cost alternatives to silicon interposers, with the ability to scale up to larger dies and achieve higher integration densities.

3. Hybrid Bonding: Hybrid bonding, a technique that joins dies with Cu-to-Cu and oxide-to-oxide bonds, is discussed as a key enabler for high-density 3D integration. It allows for finer pitch connections, better power delivery, and reduced latency between stacked dies, making it highly suitable for AI and HPC hardware.

4. Power Delivery and Thermal Challenges: As AI and HPC chips draw increasing amounts of power, managing power delivery and heat dissipation becomes a major challenge. The paper discusses advanced power delivery methods, such as vertical power delivery (PowerVia), embedded voltage regulators, and embedded capacitors, to ensure efficient power management.

5. IC Substrate Innovations: The article also covers the evolution of IC substrates, including the use of organic build-up substrates and new materials like glass, which offer improved performance and reduce warping issues in large packages. These innovations support the increasing complexity of AP designs required for AI and HPC applications.

6. Future Trends: Looking ahead, the paper highlights key trends such as the emergence of Co-Packaged Optics (CPO) to address bandwidth and power efficiency limits, and the development of next-generation interconnects like UCIe (Universal Chiplet Interconnect Express) for chiplet communication.

Overall, the paper emphasizes how advanced packaging is reshaping the semiconductor landscape, enabling AI and HPC applications to overcome current limitations. It also underscores the importance of industry collaboration and standardization, particularly in chiplet integration and hybrid bonding technologies, for the future scalability and performance of AI and HPC systems.