1 Introduction
Interposer-based 2.5D IC design allows block-level heterogeneous integration, where all functional circuit blocks are designed separately under different environments and integrated, rather than designed and fabricated monolithically into a single SoC. Figure 1 shows an interposer-based 2.5D IC design and its cross-section view. The 2.5D IC has an interposer on top of the package. The functional blocks, named chiplets, are mounted on the interposer.