Direct Bridge Multi-die (DBrM) Package: A Novel Silicon Bridge Chiplet Packaging Technology Using Die-Edge Gluing Technique for Chip Reconstitution

Abstract—We present Direct Bridge Multi‑die (DBrM), a novel silicon‑bridge packaging technology that enables high‑density, scalable, and cost‑efficient chiplet integration through a die‑edge gluing–based (adhesively bonded) chip‑reconstitution process. This technique leverages capillary action on die sidewalls to form uniform edge bonds without an over‑molding step, resulting in a robust and flexible tiled structure. The process achieves excellent coplanarity and X–Y alignment, supporting 30 µm‑pitch micro‑bump joints for bridge chip and 150 µm‑pitch Cu pillar interconnects to a standard organic substrate. Consistent flow of adhesive and bonding quality were confirmed on both silicon sidewalls and molded‑resin die edges commonly used in stacked‑memory dies. Cross‑sectional analysis reveals that prior Direct Bonded Heterogeneous Integration (DBHi [1,2]) silicon‑bridge technology suffers micro‑bump deformation and damage due to chip‑package interaction (CPI) stress from CTE mismatch between silicon and organic substrates, whereas DBrM maintains nearly undeformed micro joints thanks to its reinforced edge‑bond structure. Reliability tests on DBrM packages with 30 µm‑pitch joints showed no electrical failures after 2000 cycles of temperature‑cycling test. For high‑performance power delivery, we verified the feasibility of a TSV‑bridge configuration using a dual‑sided solder‑bump bridge. Reflow self‑alignment of molten solder produced uniform solder joints on both sides without underfill during assembly, and final underfilling encapsulated all bumps simultaneously. Furthermore, DBrM supports optical‑interface integration: its architecture provides direct access to photonic‑IC surfaces, enabling adiabatic coupling between a single‑mode polymer waveguide and a photonic IC—an option not feasible in wafer-scale interposer‑based packages where chip surfaces are fully encapsulated. These results demonstrate that DBrM offers a robust, thermally reliable, cost‑efficient, and optically adaptable platform for next‑generation heterogeneous multi‑die systems across both high‑end and cost‑sensitive applications. Keywords—chiplet package, silicon bridge, die-edge gluing, TSV, co-packaged optics