HBM4 Stack-Height Change Delays Memory's Shift to Hybrid Bonding

Hybrid bonding is advancing in logic products, but its expected entry into high-bandwidth memory has moved later. Tom's Hardware reports that a JEDEC decision to permit taller HBM stacks allows HBM4 to retain established microbump connections, leaving HBM4E and HBM5 as the likely first major memory generations to adopt direct copper bonding near the end of the decade. Hybrid bonding can provide much denser vertical connections and reduce stack height, but HBM requires die-to-wafer placement of known-good memory dies. That process is slower and especially sensitive to alignment, surface flatness, and contamination. The revised schedule reduces immediate manufacturing risk for HBM4 while preserving hybrid bonding as an important packaging transition for later stacks.