The competitive landscape for High Bandwidth Memory (HBM) is undergoing a fundamental shift. As the demand for AI computing power rapidly expands, the rivalry between Samsung Electronics Co., Ltd., SK Hynix, and Micron Technology is extending beyond the race for stacking layers and capacity, moving into a new battleground centered on thermal management.
According to reports, AI chip giants like NVIDIA and AMD are pressuring HBM suppliers to enhance thermal control and low-power design capabilities. Concurrently, reports indicate that starting with HBM5, Samsung and SK Hynix will officially introduce chip-level thermal dissipation technologies. At the COMPUTEX exhibition, Samsung showcased its HBM5 model featuring its HPB (Heat Path Block) technology, while SK Hynix unveiled its iHBM solution, which integrates cooling elements directly into the package.
This strategic pivot is driven by increasingly severe thermal management challenges. The power consumption of next-generation AI server GPUs from companies like NVIDIA is approaching 1000 watts per chip, significantly increasing the overall system cooling pressure. Meanwhile, as HBM stacking layers progress towards approximately 20 layers, heat dissipation has become a critical bottleneck constraining performance and scalability.
Divergent Technological Paths
The three major players have chosen different technical approaches. Samsung is focusing on building independent heat conduction channels within the chip. SK Hynix is embedding cooling elements directly into the HBM package. Micron Technology, on the other hand, is charting a distinct path, prioritizing low-power design and Through-Silicon Via (TSV) trench cooling technology.
Samsung's HPB: Creating a Dedicated Thermal Path for D2D PHY
The HPB (Heat Path Block) technology demonstrated by Samsung at COMPUTEX is based on the core logic of creating additional heat conduction paths within the HBM structure to more effectively manage heat generated inside the chip. Samsung DS CTO Song Jae-hyuk stated that HPB has already been implemented in HBM4E, with its reliability and stability verified.
Within the HBM structure, the D2D PHY (die-to-die physical layer), responsible for ultra-high-speed data transfer between the HBM and the external GPU, has been identified as one of the primary heat sources in the base die. Samsung's HPB solution introduces an independent thermal path in the D2D PHY region, aiming to improve overall system stability by enhancing heat conduction and reducing thermal resistance.
HPB technology has been first applied in application processors like the Samsung Exynos 2600. By placing a copper structure above the chip to create a more efficient heat dissipation path, thermal resistance can be reduced by up to 16%. Song Jae-hyuk indicated that for HBM, Samsung is exploring a silicon-based HPB architecture, focusing on optimizing the arrangement of the base die and core dies. This means HPB will be integrated into the overall memory stack design rather than merely added as a top-layer cooling accessory.
SK Hynix's iHBM: Cooling Elements Integrated Directly into the Package
The iHBM solution released by SK Hynix in late May integrates cooling elements (ICEs) directly into the HBM package interior. The company plans to adopt this architecture in its next-generation products, including HBM5.
Echoing a similar focus to Samsung, SK Hynix is also targeting the thermal issues at the D2D PHY interface. The company explains that unlike traditional HBM, which relies on heat dissipation from core dies, iHBM integrates ICEs—a thermally conductive but electrically insulating silicon-based material—directly into the D2D PHY region between the HBM stack and the GPU. By constructing an additional heat dissipation path within the package, it addresses thermal management challenges at the structural level. The company claims this design can reduce thermal resistance by 30% and significantly improve operational stability.
Regarding manufacturing feasibility, iHBM relies on SK Hynix's wafer-level packaging (WLP) process and its proven MR-MUF technology to support stable mass production.
Micron's Alternative Approach: Low-Power Focus and TSV Trench Cooling
In contrast to the focused investment on in-package thermal paths by its two South Korean counterparts, Micron Technology has adopted a differentiated strategy. It centers on low-power HBM design, supplemented by Through-Silicon Via (TSV) trench cooling technology.
Trench cooling technology involves etching micro-trenches within the silicon die of an AI accelerator chip, allowing coolant to circulate and reduce internal heat accumulation. The patent and technology analysis platform PatSnap notes that a stacked memory cooling patent granted to Micron Technology in the US in 2025 describes a vertical thermal management structure based on electrically passive cooling TSVs. It involves embedding a thermally conductive layer in the base interface die, with TSVs extending through the entire memory stack to a top heat removal layer. According to PatSnap, these TSVs are dedicated to heat conduction, aligned within the same package footprint as signal TSVs without occupying additional chip area, and form a low-resistance vertical thermal path in parallel with the electrical TSV network.
Industry Trend: Thermal Management Emerges as a New Dimension in 3D Packaging Competition
PatSnap further points out that the industry as a whole is moving towards dedicated heat conduction channels. This involves bypassing high thermal resistance underfill materials and silicon die heat paths in 3D architectures to improve cooling efficiency. The platform notes that multiple players, including Micron Technology and several major Chinese memory manufacturers, are pursuing similar design directions.
As HBM stacking layers approach 20 and AI chip power consumption continues to climb, thermal management is evolving from a system-level challenge into a core proposition of package design. The technological reserves and patent portfolios of the three giants in this field are increasingly becoming crucial indicators for measuring their competitiveness in the next phase of the market.
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