Thermal Conductivity of Carbon Nanotube Composite Films
- PDF / 1,298,463 Bytes
- 6 Pages / 612 x 792 pts (letter) Page_size
- 70 Downloads / 235 Views
F3.18.1
Thermal Conductivity of Carbon Nanotube Composite Films Quoc Ngo1,2, Brett A. Cruden2, Alan M. Cassell2, Megan D. Walker2, Qi Ye2, Jessica E. Koehne2, M. Meyyappan2, Jun Li2*, and Cary Y. Yang1 1 Center for Nanostructures, Santa Clara University, 500 El Camino Real Santa Clara, CA 95050, USA 2 Center for Nanotechnology, NASA Ames Research Center Moffett Field, CA, 94035, USA ABSTRACT State-of-the-art ICs for microprocessors routinely dissipate power densities on the order of 50 W/cm2. This large power is due to the localized heating of ICs operating at high frequencies, and must be managed for future high-frequency microelectronic applications. Our approach involves finding new and efficient thermally conductive materials. Exploiting carbon nanotube (CNT) films and composites for their superior axial thermal conductance properties has the potential for such an application requiring efficient heat transfer. In this work, we present thermal contact resistance measurement results for CNT and CNT-Cu composite films. It is shown that Cu-filled CNT arrays enhance thermal conductance when compared to as-grown CNT arrays. Furthermore, the CNT-Cu composite material provides a mechanically robust alternative to current IC packaging technology. INTRODUCTION As progress continues in the ultra-large-scale-integration (ULSI) of integrated circuits, microelectronic components including transistors, and more prominently interconnects, have become increasingly more dense and compact. The consequence of increased component density manifests itself in the form of locally high power consumption. An alarming rise in power density with respect to each advancing technology generation has been observed in mainstream microprocessor technologies [1]. The need for addressing this problem is imperative for next-generation IC packaging technology. One potential solution is to find new packaging materials, such as CNTs, that exhibit high thermal conductivity along the axial direction. For a discrete multiwalled nanotube (MWNT), the thermal conductivity is expected to surpass 3000 Wm-1K-1 along the tube axis [2]. Through the use of DC-biased, plasma-enhanced chemical vapor deposition (PECVD), as demonstrated in [3], we can fabricate vertically aligned MWNT arrays on silicon wafers of ~500µm thickness and demonstrate their possible application as a heat-sink device, conducting large amounts of heat away from a localized area, such as in critical “hot spots” in ICs. This work focuses on demonstrating that CNT and CNT-Cu composite films are mechanically robust, efficient thermal conductors. Cu serves as a filler material to improve the mechanical stability of the CNT array and to serve as a lateral heat spreader. Our data shows that the structures fabricated in this study are completely reusable, unlike eutectic bonding techniques currently used in packaging technology, which is particularly important for instrument cooling in space applications.
*
corresponding author: [email protected]
F3.18.2
EXPERIMENT Description of apparatus
Data Loading...
