HBM5 Cooling Revolution! SK Hynix integrates cooling elements into the package: thermal resistance reduced by 30%

According to a report by Fast Technology on November 12, as the power consumption of AI accelerators continues to rise, the competitive focus for HBM is shifting from the number of stacked layers to the heat dissipation capabilities within the package. SK hynix's iHBM technology, released in May this year, reduces thermal resistance by over 30% by directly embedding cooling elements inside the HBM package. The goal is to introduce it starting from the HBM5 generation.

The heat dissipation path of traditional HBM is indirect: heat is first conducted outward through the core chip and then transferred to an external heat sink. However, the area with the highest power density in the entire package is precisely the D2D PHY channel that connects the HBM base die to the GPU, and it is difficult to effectively dissipate the heat from this area.

The solution of iHBM is to directly embed an integrated cooling element (ICE) in the D2D PHY area, using an insulating and highly thermally conductive silicon-based material to open a dedicated heat dissipation channel inside the package, structurally bypassing the bottleneck of indirect conduction.

The feasibility of mass production is a key advantage of this technology. iHBM adopts SK hynix's advanced MR-MUF wafer-level packaging process, which has been validated on a large scale, and is highly compatible with customers' existing system-level packaging environments. Customers can adopt it without major design modifications, significantly lowering the actual threshold.

Lee Kang-wook, head of packaging development at SK Hynix, said that iHBM is the optimal solution that combines memory design with advanced packaging technology and minimizes heat generation.

At the supply chain level, SK hynix has begun discussions with suppliers of materials, components, and equipment regarding the product introduction and mass production plans for iHBM. According to the roadmap, iHBM will be applied starting with HBM5, which is expected to be launched in 2029. During the same period, the industry is expected to shift to hybrid bonding.

The market landscape is intensifying the urgency of this technological race. According to Counterpoint data, Samsung regained its position as the global leader in the fourth quarter of 2025 with $19.2 billion in DRAM revenue, followed closely by SK Hynix with $17.1 billion.

However, in the HBM segment, SK Hynix still holds an absolute dominant position with a share of approximately 57%, while Samsung and Micron hold 22% and 21% respectively.

Source: MyDrivers (Fast Technology). Content is presented with source attribution. Read the original report.