A Design Methodology for Thermal Monitoring of Reusable Passive Interposers With RTDs

The heterogeneous integration underpinned by several advanced packaging options, such as passive interposers offers a promising direction for future integrated systems. However, the diversity of chiplets integrated in these systems can increase design complexity. A means to mitigate this situation is to reuse interposer fabrics. Consequently, reusable interposers should provide for signaling, power, and thermal issues. This work emphasizes thermal issues by introducing a novel and sufficiently accurate thermal monitoring strategy suitable for reusable passive interposers. The proposed strategy is based on metal resistance temperature detectors (RTDs) as sensors optimally arranged on a fixed rectangular grid supporting the reuse of passive interposers. A step-by-step methodology provides the design and allocation of the sensors across the interposer fabric under temperature precision and area constraints. Diverse benchmark scenarios are investigated with the proposed RTDs, which consume only $33.6~\mu \text {W}$ with a footprint of only $0.159~\text {mm}^{2}$ . Simulation results show that the proposed methodology achieves six times ( $6\times $ ) improvement in mean absolute error (MAE) for reconstructed heatmaps over conventional chiplet-based sensors. This improvement is shown for different chiplet placements onto an interposer and for 2.5-D heterogeneous systems, where the integrated components do not include any or sufficient on-chip thermal sensors to provide the required temperature precision.