2.5D Large-Scale Interposer Bonding Process Verification using Daisy-Chain for PIM Heterogeneous Integration Platform.

This paper describes a 2.5D large-scale interposer bonding process verification method using a daisy chain (DC) for PIM heterogeneous integration platform. The target platform is composed of 8 high bandwidth memories (HBMs), 2 NPUs, an RDL interposer, and a substrate. To check the feasibility of the bonding process, NPU DC die having 48μm×55μm grid μ-bump is designed with a ring-shaped DC at the edge and corner. In addition, the DC pattern for HBM PHY and the die-to-die connection is implemented line-by-line to check the high-density wire connection area which has an offset to minimize the diagonal connection. For the interposer having 192μm×220μm gird C4-bump and the substrate having 1mm×1mm BGA ball, not only IN/OUT pins but also DCs are configured. The large-scale netlists are implemented by unifying the viewpoint to the bottom view. The bonding process verification could improve the cost efficiency of the 2.5D platform and the performance of the live interposer by optimizing the placement.