A Microfluidic Cooling Strategy Enabled by Silicon-based Microchannels with Pin-Fins for Thermal Management of 2.5D Heterogeneous Integration

The thermal management is a critical challenge for high-density heterogeneous integrated systems in the post-Moore era. In this paper, we present a microfluidic cooling strategy enabled by silicon-based microchannels with sinusoidal pin-fins. The microchannels are etched in a silicon wafer by deep reactive ion etching (DRIE), leaving arrayed pin-fins in a sinusoidal profile. A BF33 glass wafer is then bonded onto the microchannels by benzocyclobutene (BCB), serving as the cover plate. According to the measurement results, the cooling efficiency of the fabricated microchannels enhances with the microfluidic flow rate, with a maximum temperature reduction approaching 300 °C for a heat source heated by 12.34 W DC power under a microfluidic flow rate of 144 mL/min. Note that the measurement results agree well with the finite element analysis (FEA) simulations with a deviation below 5%, proving the stability of the fabrication scheme as well as the feasibility of the proposed microfluidic cooling strategy in improving the thermal management of 2.5D heterogeneous integration.