Development of a two-step electrodeposition process for enhancing pool boiling

The continuous development of high performance chips and the growing miniaturization trend in the electronics and microelectronics industry require efficient systems to remove large amounts of heat over a small footprint. Pool boiling has the ability to remove large heat fluxes at small values of wall superheat and this can be further augmented by using porous or microporous surfaces. In this work, a two-step electrodeposition technique involving application of high current density for a short time, followed by a lower current density for a longer time was investigated. This technique allowed a close control of the pore size and porous layer thickness. The electrodeposition process was carefully studied and parameters for creating different morphologies of enhanced surfaces were obtained. Thickness of the coating was in range of 50-100 μm. After testing a variety of morphologies for pool boiling heat transfer with distilled water, a maximum heat flux of 1400 kW/m2 and a significant enhancement in heat transfer coefficient (HTC) of 179 kW/m2 °C was obtained from a copper chip with cauliflower-like morphology using an initial current density of 400 mA/cm2.