GoKawiilSK hynix delays hybrid bonding for HBM until HBM5, cites 775-micron package limit
At Hot Chips 2026, SK hynix's Jaesik Lee said hybrid bonding won't be ready in time for HBM4E and will instead debut with HBM5, as current HBM4 packages are already constrained by a 775-micron thickness ceiling matching standard logic wafers. To keep scaling within that limit, 16-Hi HBM4 stacks now use dies thinned to about 50 microns with half the interlayer gap of 12-Hi designs, while SK hynix continues using its existing MR-MUF bonding method through upcoming Nvidia Rubin-generation products.
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The delay shows that even leading memory makers are running into physical packaging limits as AI chips demand ever-taller, faster HBM stacks, meaning thermal and mechanical engineering—not just process nodes—will decide how fast AI memory bandwidth can grow. It also signals that Nvidia's near-term GPU roadmap, including Rubin, will rely on incremental improvements to proven bonding techniques rather than a leap to hybrid bonding.
- SK hynix will not deploy hybrid bonding until HBM5, skipping HBM4E for this transition.
- HBM stacks are capped at 775 microns to match logic wafer thickness, forcing thinner dies and tighter gaps.
- SK hynix's MR-MUF process and iHBM cooling will continue supporting HBM4 through Nvidia's Rubin GPU generation.
SK hynix Platinum P41 NVMe SSD — If SK hynix's memory engineering has you curious, its Platinum P41 is the consumer NVMe drive you can actually buy and drop into a desktop or gaming rig. It's a PCIe 4.0 M.2 SSD built with the same in-house DRAM and NAND expertise driving the company's HBM roadmap.
See SK hynix Platinum P41 NVMe SSD on Amazon → Affiliate link — we may earn a commission on purchases, at no extra cost to you. Product picked by AI based on this article; it is not a tested recommendation.Source: tomshardware.com — Luke James, 2026-08-24
Published there as: “Hot Chips 2026: SK hynix pushes hybrid bonding to HBM5 as AI memory hits 775-micron ceiling — firm extends MR-MUF through Nvidia Rubin”
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