In a conventional 2.5D package, dies attach to the interposer through microbumps - tiny solder balls that limit how fine the connection pitch can go. Eliminating them by bonding the interposer directly to the die pads pushes density further and improves signal integrity. Taiwan Semiconductor Manufacturing Co., Ltd.'s late-2024 grant claims that direct-bonded interposer.
US12165952B2, "Interposer directly bonded to bonding pads on a plurality of dies" (issued 2024-12-10), is classified in H01L 23/4334 (cooling/heat-spreading) with H01L 21/4857/486 (substrate/interposer fabrication), H01L 24/08/32/73/83 (bonding), and H01L 25/0655. The claim is on an interposer directly bonded - not microbumped - to the bonding pads of multiple dies.
Construe the direct-bond limitation. The novelty is the absence of an intervening microbump array between interposer and dies; instead the interposer's surface bonds straight to the die pads, hybrid-bonding-style. The claim turns on that direct bond across multiple dies on one interposer.
This extends hybrid bonding from the die-to-die context into the die-to-interposer interface. Where earlier TSMC bonding patents fenced stacking two dies, this one fences bonding several dies onto a shared interposer without bumps - a denser, more electrically capable version of CoWoS.
The design-around space is the attach method. A competitor using microbump attach (conventional CoWoS-S), or bonding through an intermediate layer, reaches multi-die-on-interposer integration outside a claim requiring direct interposer-to-pad bonding. As bumpless attach spreads, the claim's relevance grows.
For a portfolio analyst, this 2024 grant shows TSMC pushing CoWoS toward bumpless, higher-density integration - the natural endpoint of the advanced-packaging arms race. It sits within TSMC's enormous and growing 3D-packaging family, and anyone building a high-density multi-die package on an interposer should read TSMC's direct-bond claims as part of the freedom-to-operate map.