Integrated microchannel liquid-cooling technology is envisioned as a viable solution to alleviate an increasing thermal stress imposed by 3-D stacked ICs. Thermal modeling for microchannel cooling is challenging due to its complicated thermal-wake effect, a localized temperature wake phenomenon downstream of a heated source in the flow. This paper presents a fast and accurate thermal-wake aware thermal model for integrated microchannel 3-D ICs. A combination of the microchannel thermal-wake function and the channel merging technique achieves more than 3300× speedup with less than 5% error in comparison with a commercial numerical finite volume simulation tool. With the proposed model, we characterize thermal behaviors of microchannel-cooled 3-D ICs and compare them with the case of conventional air-cooled 3-D ICs. We also demonstrate thermal-aware placements using our thermal model. It shows that the proposed model can be used to reduce peak temperatures, which is considered important for 3-D IC designs.

Integrated microchannel liquid-cooling technology is envisioned as a viable solution to alleviate an increasing thermal stress imposed by 3D stacked ICs. Thermal modeling for microchannel cooling is challenging due to its complicated thermal-wake effect, a localized temperature wake phenomenon downstream of a heated source in the flow. This paper presents a fast and accurate thermal-wake aware thermal model for integrated microchannel 3D ICs. Validation results show the proposed thermal model achieves more than 400x speed up and only 2.0% error in comparison with a commercial numerical simulation tool. We also demonstrate the use of the proposed thermal model for thermal optimization during the IC placement stage. We find that due to the thermal-wake effect, tiles are placed in the descending order of power magnitude along the flow direction. We also find that modeling thermal-wakes is critical for generating a thermal-aware placement for integrated microchannel-cooled 3D IC. It could result in up to 25°C peak temperature difference according to our experiments.