Highly Thermal Conductive Copper Nanowire Composites with Ultralow Loading: Toward Applications as Thermal Interface Materials

Abstract

Thermal interface materials (TIMs) are of ever-rising importance with the development of modern microelectronic devices. However, traditional TIMs exhibit low thermal conductivity even at high loading fractions. The use of high-aspect-ratio material is beneficial to achieve low percolation threshold for nanocomposites. In this work, single crystalline copper nanowires with large aspect ratio were used as filling materials for the first time. A thermal conductivity of 2.46 W/mK was obtained at an ultralow loading fraction, ∼0.9 vol %, which was enhanced by 1350% compared with plain matrix. Such an excellent performance makes copper nanowires attractive fillers for high-performance TIMs.

Large-Scale Cu Nanowire Synthesis by PVP-Ethylene Glycol Route

“…Consequently, the research on the development of Cu NWs are on the rise due to the availability of cheap and abundant resources, high electrical properties, and low migration problem despite the fact that Cu has showed low stability in moist and oxidizing atmospheres [4][5][6][7][8]. Consequently, several physical and chemical routes have been developed to synthesize Cu NWs; however, in most cases, the chemical routes are considered due to simplicity and scalability of these techniques in contrast to other routes [9][10][11][12][13][14][15][16][17][18][19][20][21][22]. Among the developed chemical techniques, aqueous synthetic route using hydrazine as the reducing agent is researched intensively [13][14][15][16][17][18].…”

“…However, this technique uses high concentrations of sodium hydroxide (NaOH) and requires stringent washing technique to remove the alkali that could hamper the conductivity of Cu NWs due to surface oxidation. On the other hand, long alkyl amine-mediated synthesis of Cu NWs has gained importance due to the possibility of dispersing and storing the products in organic solvents that could avoid rapid oxidation [19][20][21][22]. In this method, alkyl amines function as the reducing, protecting, and growth-controlling agent.…”

Electrically insulating POE/BN elastomeric composites with high through-plane thermal conductivity fabricated by two-roll milling and hot compression

“…Carbon-based materials and metallic fillers such as graphite [5], graphite/graphene nanoplateles (GNPs) [6,7], graphene [8], carbon nanotubes (CNTs) [9], carbon fiber [10,11], silver particles, silver nanowires [12], and copper nanowires [2,13] have been widely utilized to fabricate polymer-based TIMs owing to their extraordinary inherent thermal conductivity [14,15]. However, the incorporation of electrically conductive fillers will inevitably cause the great deterioration of electrical insulation performance, which hinders the wide use of these TIMs in next-generation microelectronics devices [16,17] such as LED devices with chips directly placing on the heat sink, single chip packages [18], and high-voltage devices.…”

Great Thermal Conductivity Enhancement of Silicone Composite with Ultra-Long Copper Nanowires

“…Among various nanowires, copper nanowires (CuNWs) are one of the hottest one due to their excellent electrical and thermal conductivity. Meanwhile, except for electrical and thermal conductivity, it has been confirmed that the morphology of CuNWs also plays an important role in the performance of polymer composites with CuNWs as functional fillers [10–14]. …”