SK Hynix has struggled with HBM4 back-end issues for over a year, Samsung tipped to lead HBM market next year
zephyr_z9 · x · 2026-10-14
SK Hynix's HBM4 back-end packaging troubles have reportedly persisted for over a year. The company's MR-MUF process gave it the lead over Samsung and Micron in HBM2E/3/3E, but is now the source of its HBM4 problems.
The core issue: to meet JEDEC specs, the gap between stacked DRAM dies was narrowed so much that the viscous underfill (MUF) material is hard to inject stably. MUF protects and insulates the dies; uneven application with voids causes chip defects. The attached report says Hynix's new packaging strategy includes thickening some upper-layer DRAMs (previously ground down to 775 micrometers, making them fragile) while further shrinking die spacing for power efficiency, claiming stable yield without major process changes, with positive recent internal test results.
The poster predicts Samsung will take the highest HBM market share next year. ZDNet reported in March that Hynix was struggling with underfill injection.
More from Infra
- RouterPlus pools demand so small teams get bulk-rate LLM inference pricing — rohanpaul_ai · 2026-10-14
- llama.cpp ships inside Google's Android AICore powering Gemini Nano — ggerganov · 2026-10-14
- FLAT brings open-source linear attention training kernels to TPUs, up to 3x faster — SonglinYang4 · 2026-10-14
- Artist built a 300-clip immersive exhibition with MiniMax H3, benchmarks GPU render times — komarco · 2026-10-14
- Nvidia reportedly to announce $28B AI investment in Europe this week — rchardkovacs · 2026-10-14
- RISC-V crypto accelerator SoC gets full place-and-route done with ~$2,000 of LLM tokens — IgorCarron · 2026-10-14