Thermal properties of carbon nanotube array used for integrated circuit cooling

Abstract

Carbon nanotubes ͑CNTs͒, owing to their exceptionally high thermal conductivity, have a potential to be employed in micro-and optoelectronic devices for integrated circuit ͑IC͒ cooling. In this study we describe a photothermal metrology intended to evaluate the thermal conductivity of a vertically aligned CNT array ͑VCNTA͒ grown on a silicon ͑Si͒ substrate. Plasma-enhanced chemical vapor deposition, with nickel ͑Ni͒ as a catalyst, was used to grow CNT. The experimentally evaluated thermal conductivity of the VCNTA and the thermal contact resistance at the interface between the VCNTA and the "hot" surface was found to be in a satisfactory agreement with theoretical predictions. The measured effective thermal resistance is measured to be 0.12ϳ 0.16 cm 2 •K/W. This resistance was compared to the measured resistance of commercially available thermal grease. Based on this comparison, we conclude that, although the thermal resistance of CNTs might not be as low as it might be desirable, there exists a definite incentive for using VCNTA of the type in question for IC cooling.

Carbon Nanotube Array Thermal Interfaces for High-Temperature Silicon Carbide Devices

“…The opportunity to reduce interfacial thermal inefficiencies through the use of CNT arrays considered herein would substantially enhance their reliability and utility. Previous studies [7][8][9][10][11][12][13][14][15][16] have demonstrated that multiwalled carbon nanotube (MWCNT) arrays grown on one side of an interface can achieve room-temperature thermal resistances as low as 7-25 mm 2 K/W, depending on the method of fabrication and array morphology. Using transient optical techniques, Wang et al [11], Cola et al [13], and Tong et al [14] revealed that the interfaces between MWCNTs and their growth substrate and the interfaces established at the free ends of MWCNTs can be significant thermal bottlenecks in MWCNT array interfaces.…”

“…Using transient optical techniques, Wang et al [11], Cola et al [13], and Tong et al [14] revealed that the interfaces between MWCNTs and their growth substrate and the interfaces established at the free ends of MWCNTs can be significant thermal bottlenecks in MWCNT array interfaces. Therefore, to promote good thermal contact at the MWCNT-growth substrate interface, adhesion layers (e.g., Ti, Mo, or Cr) are often deposited on the substrates before MWCNT fabrication [9][10][11][12][13][14][15]. Additionally, Tong et al [14] demonstrated that the resistance at the MWCNT free ends' interface, which was an order of magnitude higher than the resistance at the MWCNT-growth substrate interface, can be reduced up to an order of magnitude by using a thin layer of indium to weld the MWCNT ends to the opposing substrate.…”

Molecular dynamic investigation on the structures and thermal properties of carbon nanotube interfaces

“…51306108, 51176106), the Basic Research [29] Experiments CNT/CNT 50 nm 0.2e7 Â 10 À8 m 2 K/W Yang et al [30] Experiments CNT/Au >3.5 mm 2.1 Â 10 À7 m 2 K/W Xu et al [31] Experiments CNT-Cu 16 nm 4.0 Â 10 À8 m 2 K/W…”

“…The estimated data from the result of Ref. [31] is in the calculation range (0.3e7.0 Â 10 À8 m 2 K/W).…”

Nanofins: Science

“…Nanotubes are also used to synthesize nanofluids which find applications in cooling and thermal storage technologies. Nanotubes have, therefore, been proposed for applications as nanofins to cool high heat flux electronic devices and as highly conducting thermal interface materials between microprocessor chips and heat sinks (Kordas et al 2007;Xu et al 2006Xu et al , 2007.…”