Thermal performance of a silicon-interposer with embedded fluid channels enabling dual-side heat removal

Future high-power chip stacks with several hundred Watts of power dissipation rely on novel cooling topologies. In this paper, we are introducing dual-side convective cooling considering a lid-integral silicon cold plate in combination with an interposer with embedded fluid cavity. The cavity in the interposer is established by two back-to-back bonded interposer shells with integrated fluid channels. This approach allows the implementation of a cavity height of 240 μm at a through-silicon-via pitch of 225 μm. Interposer test vehicles are fabricated to explore the heat removal capability of three different cavity designs; Channel 2-Port, Pin-Fin 2-Port and Channel 4-Port. They are studied with respect to their thermal response on uniform and non-uniform power maps. The projected power map of a three-tier chip stack with an aggregate power dissipation of more than 600W on 4cm 2 area is considered. Heat and mass transport experiments are performed. Changes from laminar to transitional flow regimes are discussed. The transition is most prominent for the pin-fin cavity, indicated by a drastic pressure drop increase above 0.15 L/min and a junction temperature drop. The 4-port design with microchannels outperformed the other designs, considering pressure drop as the relevant boundary condition. The performance difference can be large especially for non-uniform heat fluxes and needs to be studied on a case-by-case basis.