# SK hynix pushes hybrid bonding in HBM back to HBM5, delaying a key market for Besi

Canonical page: https://technooptimist.io/stories/sk-hynix-pushes-hybrid-bonding-in-hbm-back-to-hbm5-delaying-a-key-9637cdf3
Date: 26 Aug 2026
About: [Besi (BE Semiconductor Industries)](https://technooptimist.io/companies/besi.md) · [Besi hybrid bonding systems](https://technooptimist.io/computing/hybrid-bonding.md)
Original source: https://bits-chips.com/article/besi-faces-longer-wait-as-sk-hynix-pushes-hybrid-bonding-to-hbm5/

At Hot Chips 2026, SK hynix said it will keep microbump stacking through HBM4E and move to hybrid bonding a generation later. A JEDEC change raised the maximum stack height from 720 to 775 microns, so dies need less thinning, the main pressure that favoured hybrid bonding.

## Key facts

- SK hynix reportedly ordered a pilot hybrid-bonding line with Applied Materials and Besi tools; follow-up orders may slip.
- Reliable copper-to-copper bonds across 16 or 20 stacked dies remain a major challenge, SK hynix said.
- 12-high HBM is in mass production; 16-high is in customer qualification.

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