High Bandwidth Memory in NVIDIA HGX B300: Examining the Micron HBM3E Package

An Analysis of the Interconnect and Packaging Architecture

TechInsights completed an interconnect and packaging analysis of the Micron 12Hi HBM3E memory package extracted from an NVIDIA HGX B300 Blackwell Ultra accelerator. This is the first Micron high-bandwidth memory (HBM) device analyzed by TechInsights. Using cross-section imaging, X-ray inspection, scanning electron microscopy (SEM), and delayering, the analysis characterizes the full 3D die stack.

High bandwidth memory packaging has become an important differentiator in AI accelerator performance. Micron's entry into HBM3E supply for NVIDIA marks the third major HBM supplier in a market previously dominated by SK hynix and Samsung. TechInsights' analysis provides an independent physical view of Micron's interconnect and packaging architecture and the data needed to compare its implementation with competing HBM designs.

Figure 1 – Interconnect and packaging analysis of the Micron 12Hi HBM3E package (Source: TechInsights)

Reverse Engineering the NVIDIA Blackwell Ultra HGX B300

The NVIDIA HGX B300 is a high-priority target for competitive intelligence because of its role in AI training infrastructure and the strategic importance of HBM supply to NVIDIA's accelerator roadmap. Its current competitive landscape includes AMD’s MI350 series, Intel's Gaudi 3, and various hyperscaler-developed Application-Specific Integrated Circuits (ASICs), each addressing different parts of the AI infrastructure market. In particular, AMD's MI350 series represents the most direct GPU competition, with notable performance gains.

To understand the innovations used during manufacturing, TechInsights has completed a series of structural and materials analyses stemming from the initial NVIDIA HGX B300 server teardown. At the server level, we benchmarked a single physical node, the ASRock 8U16X-GNR2-B300 AI GPU rackmount server, using workloads representative of actual production conditions. We’ve now moved deeper into the system’s High Bandwidth Memory (HBM) package, providing information on the form factor and insights into architectural attributes that may affect performance or thermal management.

Examining High Bandwidth Memory Interconnect and Packaging

The Micron HBM3E uses a Micro Pillar Grid Array (MPGA) package with 36 GB of memory capacity in a 12Hi configuration. Compared with competing HBM3E 8H 24 GB devices, it provides 50% more memory capacity and, according to Micron, up to 20% lower power consumption.

The analysis covers the full packaging stack, from the CoWoS-L interposer interface through the 12-layer DRAM die stack to the controller die. It characterizes interconnect pitch, through-silicon via (TSV) density, bonding materials, underfill chemistry, and dicing methods. Teams evaluating HBM3E supplier qualification, second-sourcing risk, or packaging roadmap positioning will find the structural and dimensional data needed to benchmark Micron's implementation against published and reverse-engineered data from competing devices.