Theoretical and numerical study on thermoelectric transient cooling for hotspot elimination under alternating current mode

The escalating power density in modern microelectronics gives rise to high-frequency thermal hotspots that pose severe challenges to on-chip thermal management. Microscale thermoelectric coolers (μ-TECs), possessing unique advantages such as, rapid response, precise temperature control, and high reliability, offer promising solution for localized chip-level cooling. However, conventional steady-state and transient pulse cooling methods remain insufficient for dissipating the sustained, ultra-high heat flux generated by these hotspots. In this study, we investigated the heat transport behavior of thermoelectric cooling under alternating current mode through a combined approach of analytical modeling and finite element simulations. The results demonstrated that the hotspot temperatures could be effectively suppressed by optimally matching the amplitude and phase of the alternating current applied to μ-TECs. Additionally, high thermal conductivity and low interfacial contact resistance further enhanced active cooling performance. Furthermore, the integration of a negative direct current offset into the optimized silicon-based μ-TEC achieved a 3.29 K reduction in peak hotspot temperature and significantly reduced temperature fluctuation from 65.62 K to 20.66 K, under an ultra-high heat flux of 6.37 kW/cm². This study points out the priorities for materials research and device optimization for on-chip μ-TECs and paves the way for achieving transient thermal management of chip hotspots.