Self-Aligned Silicon Interposer Tiles and Silicon Bridges Using Positive Self-Alignment Structures and Rematable Mechanically Flexible Interconnects

A novel large-scale silicon system platform is proposed and demonstrated. In this paper, three silicon interposer tiles are aligned and mounted on a printed wiring board (PWB), and two silicon bridges are aligned and mounted on top of the three interposer tiles; each silicon bridge spans two interposer tiles. Four positive self-alignment structures and four inverted pyramid pits self-align a tile to the PWB and a bridge to two tiles. Mechanically flexible interconnects (MFI) form nonbonding electrical connections between the three interposer tiles and two silicon bridges; MFIs are fabricated on the interposer tiles. Pointy tips on the MFIs form low contact resistance with the pads on the silicon bridges. Less than 4 μm alignment error is demonstrated on a stack of silicon substrates, and <;8μm alignment error between a silicon bridge and tiles is also demonstrated on a FR4 substrate. Daisy chain and four-point measurements are performed to verify electrical connections between the three interposer tiles via MFIs and silicon bridges.