Transient Response of Microchannel Heat Sinks in a Silicon Wafer

Abstract

The transient conjugated heat transfer in forced convection for simultaneously developing laminar flow inside a microchannel heat sink is studied by solving the steady momentum equation and the transient energy equation. A parametric study is performed to understand the effects of channel depth and width, Reynolds number, spacing between channels, and solid to fluid thermal conductivity ratio. Silicon as well as indium phosphide are used as wafer’s material. Step and pulsed variations of the heat load are analyzed. Results show that the time required for the heat transfer to reach steady state condition is longer for the system with larger channel depth or spacing and smaller channel width or Reynolds number. Characteristic results for the fluid mean temperature at the exit, solid maximum temperature, local Nusselt number, and local heat flux are presented graphically as functions of position and time.