How densely you stack and connect chiplets is physically decided by bonding technology. In place of conventional solder bumps, hybrid bonding — connecting copper directly — has emerged as the frontrunner for the next generation. If CoWoS and HBM are the "vessels" of packaging, hybrid bonding is the core process that raises chiplet density and power efficiency within them.
Leading this area is, surprisingly, not Asia but the US and Europe: the alliance of America's Applied Materials and the Netherlands' Besi, and Germany's SÜSS MicroTec. Equipment is prone to becoming a single point of failure in advanced packaging, so who holds which precision is a supply linchpin.
What is hybrid bonding
Hybrid bonding is a next-generation packaging technology that raises chiplet density and power efficiency through direct copper-to-copper bonding. By connecting metal directly, without solder bumps, it greatly increases I/O density. The targeted markets span five — HPC, AI, 5G, data storage, and automotive — governing the performance not just of AI but of high-performance computing broadly.
Telling is the stance of the equipment majors. Applied Materials' corporate VP for Advanced Packaging officially acknowledged the limits of Moore's Law and proposed a "new playbook." The equipment side has declared the shift from a front-end-scaling-only path to one that grows performance through packaging.
Applied×Besi — the industry's first integrated bonder
Applied Materials and Besi have collaborated since 2020 to develop the industry's first complete equipment solution for die-based hybrid bonding. Their joint program is designed as a fusion of "front-end materials engineering × back-end advanced packaging," bringing front-end materials and process technology into back-end bonding.
The tie was strengthened at the capital level too. Applied Materials acquired 9% of the outstanding shares of Besi, its co-development partner. Besi is a leading maker of semiconductor assembly equipment, a leader in die-attach, interconnect, and assembly. Applied Materials frames hybrid bonding as "the foundation of AI chips," stressing its strategic importance.
SÜSS MicroTec — a world-first W2W/D2W integration
European players are also at the front. Germany's SÜSS MicroTec's XBC300 Gen2 is the world's first hybrid bonding platform integrating W2W (wafer-to-wafer), collective D2W, and sequential D2W (die-to-wafer) in a single cluster. It concentrates in one tool the flexibility to switch bonding methods by application.
Precision is high. The XBC300 Gen2 achieves ±100 nm accuracy and up to 300 N bond force via SET Corporation SA's NEO HB die bonder, and in W2W bonding achieves alignment accuracy below 100 nm via ISA technology. It handles both 200–300 mm wafers and dies on tape-frame carriers, covering diverse production formats. In this process, where nanometer-scale alignment decides yield, tool precision translates directly into competitiveness.
How to read the equipment race
Hybrid bonding: key players
01
Applied×Besi (US/NL)
Collaborating since 2020 to develop the industry's first integrated die bonder. Applied took a 9% Besi stake to deepen ties. Targets five markets including HPC/AI/automotive; framed as 'the foundation of AI chips.'
02
SÜSS MicroTec (Germany)
XBC300 Gen2 is the world's first tool integrating W2W, collective/sequential D2W in one cluster. ±100 nm accuracy; W2W below 100 nm. Handles 200–300 mm and tape frames.
03
Why it's the frontrunner
Copper direct bonding raises I/O density and power efficiency. An equipment VP acknowledged Moore's Law limits, stating a 'new playbook' to grow performance through packaging.
04
Implication for buyers
Nanometer alignment decides yield — a single point of failure. Who holds which precision and method becomes a linchpin of advanced-packaging supply.
Business impact and checkpoints
From a procurement and investment view: (1) whether the advanced package you adopt depends on hybrid bonding, and whether its equipment supply (Applied×Besi, SÜSS, etc.) is secured; (2) which of W2W/D2W methods fits your design and production format; and (3) how far the tool's alignment accuracy and throughput make yield and volume-production effective. Bonding equipment is inconspicuous, but it is a single point of failure that physically decides chiplet density and yield — worth tracking how the equipment race unfolds.
