Experimental Demonstration of an Additively Manufactured Vapor Chamber Heat Spreader

Abstract

Vapor chambers and heat pipes are often used as standalone heat spreaders for electronics cooling and in other applications. Metal additive manufacturing (AM) techniques have an intrinsic ability to form the porous structures and internal cavities required to fabricate a vapor chamber or a heat pipe. Additive manufacturing techniques thereby have potential for fabricating vapor chambers with complex geometries and locally tailored wick structures to improve performance as well as to monolithically embed vapor chamber heat spreaders within other components. The focus of the present work is to conduct an experimental assessment of the viability of additively manufactured vapor chambers. A direct metal laser sintering (DMLS) technique was used to fabricate a monolithic stainless steel vapor chamber heat spreader with a 39% porous, 0.5-mm thick wick and a 1.5-mm thick internal vapor core. The functionality of the as-printed vapor chamber was evaluated based on characterization of the heat spreading behavior with and without fluid charge. Charging with water decreased the effective thermal resistance of the device while spreading heat from a central hot spot, confirming functionality of the additively manufactured vapor chamber.