Samsung and SK hynix deploy cooling packaging on HBM4E chips

Samsung Electronics and SK hynix accelerated thermal packaging deployments on Oct. 12, 2026, targeting heat dissipation limits as AI interposers expand to support 16-layer HBM4E memory stacks.

Larger silicon interposers house multiple accelerator processors alongside high-bandwidth memory stacks. This dense integration concentrates thermal loads and causes structural warpage across the underlying substrate.

SK hynix embeds silicon cooling blocks to cut thermal resistance by 30%, the company said. Samsung Electronics uses power network tuning to lower thermal resistance by 10% on initial high-bandwidth stacks.

Both South Korean manufacturers are redesigning internal die interfaces. The shift reflects physical constraints as accelerator vendors prepare platforms that require data throughput exceeding four terabytes per second.

SK hynix unveiled its integrated cooling architecture, termed iHBM, on May 26, 2026. The architecture inserts non-conductive silicon structures directly into the base layers of the memory stack.

The company places these integrated cooling elements within the die-to-die physical layer. That interface connects the memory stack directly to the host accelerator and generates the highest heat density.

Direct heat channels pull thermal energy outward into external heat sinks. Conventional packages forced heat to travel through upper core memory dies before reaching the surface, SK hynix said.

SK hynix manufactures these packages with advanced mass reflow molded underfill technology. The technique injects liquid protective material between stacked dies to ensure structural stability without altering customer system layouts.

The supplier shipped 12-layer HBM4E samples operating at speeds up to 16 gigabits per second in June 2026. SK hynix plans to introduce the cooling element design across seventh-generation and eighth-generation lines.

Samsung Electronics approaches the thermal bottleneck through low-power circuitry and direct copper interfaces. The company commercialized its sixth-generation HBM4 memory on Feb. 12, 2026, using four-nanometer logic base dies.

Samsung redesigned its internal power distribution network to curb parasitic electrical resistance. That architecture improved heat dissipation by 30% compared to previous-generation HBM3E products, the company said.

Samsung displayed its seventh-generation HBM4E memory at the Nvidia GTC conference on March 17, 2026. The component achieved 16 gigabits per second per pin and 4.0 terabytes per second of bandwidth.

The manufacturer also presented hybrid copper bonding to assemble stacks reaching 16 layers or more. The process bonds copper pads directly between dies without using intermediary micro-bumps.

Eliminating micro-bumps reduces package height and tightens vertical thermal conduction paths. Samsung said the technique reduces thermal resistance by more than 20% compared to traditional thermal compression bonding.

The company completed initial shipments of 12-layer HBM4E samples on May 28, 2026. The design improved thermal resistance characteristics by 14% over baseline sixth-generation silicon, Samsung said.

Thermal dissipation has become the primary operational barrier for advanced accelerators. Expanding interposer surface areas increases thermal expansion mismatches between silicon dies, organic substrates and bonding layers.

When thermal expansion rates diverge under heavy data center workloads, interposers flex unevenly. That mechanical strain cracks micro-bump joints and degrades electrical continuity across memory channels.

Nvidia plans to integrate these dense memory stacks into its Vera Rubin computing platform. The architecture couples high-bandwidth memory with central processors and graphical processing units on single packaging substrates.

Memory suppliers must resolve mechanical warping before cloud service providers deploy these accelerator systems. Thermal degradation reduces overall computational throughput by forcing processors to throttle operating frequencies.

SK hynix relies on its established liquid underfill ecosystem to maintain assembly yields. Samsung relies on its integrated device manufacturing structure, combining in-house foundry fabrication with advanced packaging lines.

Both manufacturers expect qualification testing for 16-layer stacks to finish before volume production begins in early 2027. Customer validation milestones scheduled for November 2026 will determine production ramp allocations.

The companies did not disclose the commercial yield rates of their hybrid copper bonding lines. Neither manufacturer has published volume contract pricing for finished 16-layer HBM4E stacks.

Samsung continues engineering evaluations for custom memory logic dies at its Hwaseong packaging facility. SK hynix runs parallel thermal stress assessments with customer engineering teams in Icheon, South Korea.