[News] Samsung Considers Hybrid Bonding a Must for 16-stack HBM

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According to the latest report by TheElec, though Samsung has been using thermal compression (TC) bonding until its 12-stack HBM, the company now confirms its belief that hybrid bonding is necessary for manufacturing 16-stack HBM.

Regarding its future HBM roadmap, Samsung reportedly plans to produce its HBM4 sample in 2025, which will mostly be 16 stacks, with mass production slated for 2026, the report noted. According to TheElec, earlier in April, Samsung used hybrid bonding equipment from its subsidiary, Semes, to produce a 16-stack HBM sample, of which it indicated to operate normally.

Citing information Samsung revealed during the 2024 IEEE 74th Electronic Components and Technology Conference last month, TheElec learned that Samsung considered hybrid bonding essential for HBM with 16 stacks and above.

According to the report, Samsung has been using thermal compression (TC) bonding until its 12-stack HBM. However, now it emphasized on hybrid bonding’s ability to reduce height, which would be indispensable for 16-stack HBM. By further narrowing the gap between chips, 17 chips (one base die and 16 core dies) can be fitted within a 775-micrometer form factor.

According to an earlier report from TechNews, Samsung and Micron use TC-NCF technology (thermal compression with non-conductive film) on HBM production, which requires high temperatures and high pressure to solidify materials before melting them, followed by cleaning. The industry has relied on traditional copper micro bumps as the interconnect scheme for packages, while their sizes pose challenges when trying to allow more chips to be stacked at a lower height.

Samsung stated that though making the core die as thin as possible or reducing the bump pitch could help, these methods have reached their limits. Sources cited by the Elec mentioned that it is very challenging to make the core die thinner than 30 micrometers. Also, using bumps to connect the chips has limitations due to the volume of the bumps. Thus, hybrid bonding technology may emerge as a promising solution.

While the current technology uses micro bump materials to connect DRAM modules, hybrid bonding, which could stack chips veritically by using through-silicon-via (TSV), can eliminate the need for micro bumps, significantly reducing chip thickness.

On the other hand, according to another report by Business Korea, SK hynix has shown its confidence in the HBM produced with Mass Reflow-Molded Underfill (MR-MUF) technology. MR-MUF technology attaches semiconductor chips to circuits, using EMC (liquid epoxy molding compound) to fill gaps between chips or between chips and bumps during stacking.

SK hynix reportedly plans to begin mass production of 16-layer HBM4 memory in 2026, and the memory heavyweight is currently researching hybrid bonding and MR-MUF for HBM4, but yield rates are not yet high, the report said.

Read more

• [News] The HBM4 Battle Begins! Memory Stacking Challenges Remain, Hybrid Bonding as the Key Breakthrough
• [News] Jensen Huang Confirms NVIDIA Approaches Certification of Samsung’s HBM Chips

(Photo credit: Samsung)