Numerical investigation of electro-thermal coupling in TSV-embedded microchannel cooling with variable cross-section cylindrical fin structures

Three-dimensional integrated circuits (3D-ICs) offer substantial benefits in integration density and interconnect performance, yet impose severe thermal management demands owing to localized heat flux densities that routinely exceed 100 W/cm 2 , particularly in regions proximate to through-silicon vias (TSVs). This study presents a novel microchannel thermal management architecture in which TSVs are embedded within cylindrical pin-fins featuring systematically varied cross-sectional geometries. A fully coupled electro-thermal numerical framework is developed to simultaneously resolve Joule heating within TSV copper cores and three-dimensional forced convective heat transfer in the surrounding deionized water coolant. Two distinct geometric modification strategies are investigated: concave (inward-curved) and convex (outward-bulged) sidewall profiles, parameterized by radial deformation amplitudes e 1 and e 2 , respectively. Comprehensive parametric studies are conducted over a Reynolds number range of 200–800. Numerical results indicate that concave configurations reduce pressure penalties by up to 15% relative to the baseline, but simultaneously attenuate boundary layer disruption and diminish convective heat transfer coefficients, resulting in elevated TSV junction temperatures. In contrast, convex geometries enhance near-wall velocity gradients and promote flow mixing, achieving maximum and mean TSV temperature reductions of approximately 20 K and 15 K, respectively, relative to concave designs. Despite incurring higher pressure drop penalties, convex fin configurations yield normalized Nusselt number improvements and performance evaluation criterion ( η ) enhancements of 15%–30%, confirming their viability as an effective thermal management solution for high-power-density 3D-IC applications.