Committee Members:

Dr. Vanessa Smet, ME (Co-Advisor)
Dr. Antonia Antoniou, ME (Co-Advisor)
Dr. Eric Vogel, MSE (Co-Advisor)
Dr. Preet Singh, MSE
Dr. Meisha Shofner, MSE

ENHANCING THE PROPERTIES OF COPPER FOAM WICKS USING GRAPHENE COATINGS FOR HIGH-PERFORMANCE VAPOR CHAMBERS AND HEAT PIPES

Abstract: With the increasing thermal densification of consumer and portable electronics, the implementation of two-phase capillary flow-driven structures (e.g., vapor chambers, heat pipes) in thermal management has grown exponentially. These structures utilize the latent heat of evaporation of a working fluid along with the thermal and capillary capabilities of a wick to efficiently mitigate hot spots through heat spreading; however, material development for improved thermal capabilities of these two-phase wick systems is underdeveloped for what is needed in future electronic packages. As a result, this research explores the use of conformal graphene coatings deposited on open-cell copper foams to enhance their properties and performance. A controlled chemical vapor deposition process was utilized to conformally coat monolayer graphene on different copper foam densities with varying pore sizes and 3D connectivity. The thermal, electrical, and mechanical properties were then characterized before and after the graphene was deposited to understand the effect of the coating on the foams. Permeability and wettability were also evaluated to understand the potential of the coating on high-performance wicks. An electroless copper deposition process was then developed to deposit a conformal intermediate copper layer that could separate parallel graphene networks with further sequential deposition of alternating graphene and copper layers. This thesis reports the resulting improvements in wick properties and performance from graphene coatings, establishing this method as a promising pathway for compact and highly efficient in-package heat spreading solutions, and provides design guidelines to maximize benefits from this material innovation with considerations of ease of processability and cost.