Shares of BE Semiconductor Industries (Besi) fell by over 7% after media reports conveyed that the timetable for adopting hybrid bonding in high-bandwidth memory chips may move further into the future. The development centers on manufacturers reportedly choosing thermocompression bonding for HBM4 chips and saving hybrid bonding for the more advanced 16-layer HBM4E generation.
According to the report, some industry participants now anticipate a slower progression to hybrid bonding given manufacturers' current preference for established thermocompression techniques when assembling HBM4. That has prompted investors to reassess growth expectations for Besi, a company positioned as a first mover in hybrid-bonding equipment.
Analyst Michael Roeg at Degroof Petercam summarized the concern by noting that hybrid bonding adoption by HBM customers could encounter additional postponements "due to height relaxation and net technologies to dissipate heat better than before." The comment highlights technical trade-offs manufacturers are weighing as they balance packaging density against thermal and mechanical constraints.
Hybrid bonding is a packaging method that links chips via direct copper-to-copper connections instead of relying on conventional solder. This technique enables denser interconnect layouts and shorter wiring between chiplets, which can translate to improvements in performance, power efficiency and cost for advanced logic and memory devices. Those attributes have made hybrid bonding a focal point for equipment vendors and chipmakers targeting AI applications.
Besi has been developing hybrid-bonding tools in collaboration with U.S. equipment maker Applied Materials since 2020. That partnership culminated in Applied Materials taking a 9% stake in Besi last year. The strategic tie and investment reflected expectations that hybrid bonding would play a growing role in packaging next-generation memory and logic chips.
Market reaction to the report reflects concern that any delay in hybrid bonding adoption would slow BESI's revenue ramp tied to that technology. A protracted transition to hybrid bonding could compress near-term growth assumptions for Besi even if the technology remains important for future generations of memory chips.
For industry participants and investors, the issue underscores technical and commercial uncertainty around which bonding approaches will dominate across successive memory generations. The decision by manufacturers to retain thermocompression for HBM4 while reserving hybrid bonding for 16-layer HBM4E highlights the stepwise nature of technology adoption in semiconductor packaging.
Sectors affected: Semiconductor equipment manufacturers, memory chip supply chain, and AI hardware markets.