Thermal Characterization of Multi-Layer Graphene Heat Spreader by Pt/Cu/Ti Micro-Coil

摘要

Hotspot cooling by heat spreader is essential to avoid reliability issues of the powerelectronic devices. Herein, the evaluation of the heat spreading capability ofmono- and multi-layer graphene using a Pt/Cu/Ti micro-coil heater-thermometer isreported. Monolayer graphene is grown and transferred onto the test structurewhich consists of micro-coil, pads, and heat sinks. The temperature coefficient ofresistance of the bare coil is around 0.0087 °C~（-1）. During Joule heating, the barestructure dissipates heat from the coil mainly via stage. Deposited graphene helpscarry heat from the coil to the peripheral heat sinks. In transient-state Joule heating,graphene reduced all stage, coil, and hotspot temperatures. However, stagetemperature cannot be reduced during steady-state Joule heating. The thickening ofthe graphene layer did improve the heat dissipation from the coil. The optimumnumber of layers is suggested to be 3-layers graphene with a hotspot reductionfrom 5.86 °CW~（-1） down to 4.97 °CW~（-1）. More than 3-layers result in a slightincrease in hotspot temperature due to heat accumulation within the films.Findings in this work give insight into thermal management strategies inhigh-temperature power electronics.