High-speed, High-density, and Highly-manufacturable Cu-filled Through-Glass-Via Channel (Cu bridge) for Multi-chiplet Systems

A previously presented topside Cu-filled through-glass-via channel (a “Cu bridge”) is expected to be better able to support high-speed high-density signal processing in multi-chiplet systems than Cu through-glass vias based on existing electroplating techniques (conformal filling and bottom-up filling). Large-scale processing of glass interposers embedded with these Cu bridges has now been demonstrated using both a glass panel (300 mm ×400 mm) and a glass wafer (300 mm diameter) as another step towards achieving high-volume mass production of a glass interposer embedded with these bridges. For as many as 10 million Cu bridges embedded in the panel (100-μm-pitch fully arrayed through-glass via), there were no via-opening or via-filling failures. The thermal stability of the Cu bridge against thermal stressing was demonstrated by thermal cycle testing with electrical inspection. The simulated heat dissipation and signal transmission capabilities of a glass interposer embedded with Cu bridges were comparable those of a silicon interposer. The cost of manufacturing the glass interposer is estimated to be up to 53% less than that for a silicon interposer.