- Category:
Structure of Advanced Semiconductor Packages
As mentioned in Part 1
, the widespread adoption of AI has rapidly brought advanced semiconductor packaging technologies—namely 2.5D and 3D packages—into the spotlight.
In this article, we explore the structure of these advanced semiconductor packages.
Structure of 2.5D Packages
A 2.5D package consists of an interposer—a silicon-based intermediate substrate—mounted on the package substrate. Logic chips and memory devices are placed side by side on top of the interposer. The interposer features ultra-fine wiring at the submicron level, enabling high-density connections between different chips through its surface terminals. Signals and power are then transmitted to the underlying package substrate via TSVs (Through-Silicon Vias).
Structure of a 2.5D Package
This architecture significantly shortens the distance between logic and memory chips compared to conventional 2D packages, reducing signal transmission loss and enabling high-speed, wide-bandwidth interconnects. For example, placing a GPU and HBM (High Bandwidth Memory) side by side on the same silicon interposer allows efficient utilization of HBM’s wide memory bandwidth—a configuration already in mass production.
Data transfer paths between processor and memory in advanced vs. conventional packages
Conventional：
Processor and memory each assembled The distance for transmitting electrical signals is long.
It takes time
Advanced：
Processor and memory in one package The distance for transmitting electrical signals is short.
Very fast transmission
In addition, the interposer allows direct integration of logic, memory, and analog ICs manufactured using different process technologies, making it highly compatible with the emerging chiplet approach. This approach breaks down the functions traditionally integrated into a single large chip into smaller, function-specific dies. Combining multiple chiplets improves manufacturing yield compared to large monolithic chips. Notable examples of 2.5D packaging for HPC applications include TSMC’s CoWoS (silicon interposer-based) and Intel’s EMIB 2.5D (embedded silicon bridge).
Structure of 3D Packages
3D packaging represents a cutting-edge approach where multiple chips are stacked vertically and integrated into a single unit. Because the chips are directly interconnected, the inter-chip distance is virtually zero, reducing signal delay and power consumption. This also minimizes the footprint on the substrate, enabling higher integration density.
Connections between stacked chips typically use TSVs or hybrid bonding. Hybrid bonding directly joins chips using metal and dielectric materials, achieving ultra-fine pitch and high-density interconnects. Various stacking configurations are being explored, including memory-to-memory, logic-to-logic, and logic-to-memory combinations.
Representative examples of 3D packaging include Intel’s Foveros Omni (featuring multiple base dies and TSV-based power delivery), Foveros Direct (structured with hybrid bonding for chip stacking), and TSMC’s SoIC.
Structure of a 3D Package
Summary and Next Topic
In this article, we explained the structure and benefits of advanced semiconductor packages. These technologies are essential evolutions to meet the semiconductor industry’s key demands for higher performance, smaller form factors, and lower power consumption.
In the next installment, we will discuss “Manufacturing Processes and Materials Used in Advanced Semiconductor Packages.”
Published: January 23, 2026
Related Recommendations
-
Column
The Evolution of Semiconductor Packaging
As the limits of semiconductor miniaturization become apparent, packaging technology is increasingly recognized as a key driver for performance improvement. In this article, we explain how semiconductor packaging has evolved—from lead-frame packages in the 1970s to today’s cutting-edge 3D packages.
-
Column
Manufacturing Processes and Materials Used in Advanced Semiconductor Packaging
A comprehensive guide to the manufacturing processes of advanced semiconductor packages—from interposer formation to assembly on the package substrate—along with the materials used in each step.
-
Column
Technical Challenges in Advanced Semiconductor Packaging
Key technical challenges in 3D packaging include thermal management, warpage, increased manufacturing complexity and cost, and defect detection. Each of these issues can be effectively addressed through design and process optimization, as well as the use of appropriate materials.