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

Besi (BE Semiconductor Industries)/Besi hybrid bonding systems

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.

• 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.