Fanless, porous graphene-copper composite heat sink for micro devices

Abstract

Thermal management in devices directly affects their performance, but it is difficult to apply conventional cooling methods such as the use of cooling liquids or fans to micro devices owing to the small size of micro devices. In this study, we attempted to solve this problem by employing a heat sink fabricated using copper with porous structures consisting of single-layer graphene on the surface and graphene oxide inside the pores. The porous copper/single-layer graphene/graphene oxide composite (p-Cu/G/rGO) had a porosity of approximately 35%, and the measured pore size was approximately 10 to 100 µm. The internal GO was reduced at a temperature of 1000 °C. On observing the heat distribution in the structure using a thermal imaging camera, we could observe that the p-Cu/G/rGO was conducting heat faster than the p-Cu, which was consistent with the simulation. Furthermore, the thermal resistance of p-Cu/G/rGO was lower than those of the p-Cu and pure Cu. When the p-Cu/G/rGO was fabricated into a heat sink to mount the light emitting diode (LED) chip, the measured temperature of the LED was 31.04 °C, which was less than the temperature of the pure Cu of 40.8 °C. After a week of being subjected to high power (1000 mA), the light intensity of p-Cu/G/rGO decreased to 95.24%. However, the pure Cu decreased significantly to 66.04%. The results of this study are expected to be applied to micro devices for their effective thermal management.

Exfoliation and Spray Deposition of Graphene Nanoplatelets in Ethyl Acetate and Acetone: Implications for Additive Manufacturing of Low-Cost Electrodes and Heat Sinks

“…Heat sink fins coated with a 0.5-μm layer of GrNP had a quasi-linear cooling rate of 0.63 °C/s during the first 15 s, which was 20% faster than uncoated heat sink fins (0.52 °C/s; Figure B). This result is line with other examples of graphene-based materials for heat dissipation: the thermal conductivity of an all-graphene heat sink was reported to be several times greater than its metal counterparts, and a heat sink fashioned from porous copper–rGO maintained lower temperatures relative to one without rGO …”

“…Graphite is also well known for its excellent thermal conductivity, and graphene-based dispersions and composites have been widely studied as media for heat dissipation and exchange. − ,, To determine whether the high surface area of GrNPs could be used to increase the rate of radiative heat transfer, dispersions of GrNPs were spray-coated onto the fins of aluminum heat sinks mounted on the backs of thermoelectric Peltier blocks (see the Experimental Section). The plates generated substantial amounts of heat when powered by a 12-V/5-Ah battery, with heat sink fins achieving a steady-state temperature of nearly 80 °C in ambient conditions (22.8 °C).…”

Nanoporous Organic Frameworks as Light-Emitting Diodes: A Review

“…Different porous materials have already been reported in LED applications, including silver nanoclusters confined in zeolites, rare-earth-ion-doped porous glass ceramics, porous silicon, porous graphene, and porous polymer films . In this review, a summary of different nanoporous organic frameworks (MOFs, COFs, and HOFs) that have been used in LEDs or are promising candidates for LEDs will be presented.…”