where ∆T and q are the temperature drop and heat flux across the interface. Predicting the thermal boundary resistance of semiconductor/semiconductor interfaces is important in devices where phonon interface scattering is a significant contributor to the overall thermal resistance (e.g., computer chips with high component density). Such predictions will also lead to improvements in the design o...

A model is developed in this work to predict the thermal contact resistance of carbon nanotube (CNT) array interfaces with CNT arrays synthesized directly on substrate surfaces. An analytical model for contact mechanics is first developed in conjunction with prior data from load–displacement experiments to predict the real contact area established in CNT array interfaces as a function of applie...

This work describes an experimental study of thermal conductance across multiwalled carbon nanotube CNT array interfaces, one sided Si-CNT-Ag and two sided Si-CNT-CNT-Cu , using a photoacoustic technique PA . Well-anchored, dense, and vertically oriented multiwalled CNT arrays have been directly synthesized on Si wafers and pure Cu sheets using plasma-enhanced chemical vapor deposition. With th...

The increasing power and reduced die size of CPUs used in computers increases a need for significantly improved thermal interface materials (TIM). The TIM is used to reduce contact resistance at the CPU-heat sink interface. This work provides a state-of-the-art assessment on “thermal interface materials,” including fundamentals, materials used, their performance, and how interface resistance is...

High-temperature thermal contact resistance (TCR) plays an important role in heat-pipe-cooled thermal protection structures due to the existence of contact interface between the embedded heat pipe and the heat resistive structure, and the reduction mechanism of thermal contact resistance is of special interests in the design of such structures. The present paper proposed a finite element model ...

Aligned carbon nanotube (CNT) arrays were fabricated from a multilayer catalyst configuration by microwave plasma-enhanced chemical vapor deposition (PECVD). The effects of the thickness and annealing of the aluminum layer on the CNT synthesis and thermal performance were investigated. An experimental study of thermal resistance across the CNT array interface using the modified ASTM D5470 stand...

The electrical resistance of individual multiwalled carbon nanotubes and the thermal interface resistance of nanotube arrays are investigated as functions of dc bias voltage used during growth. Nanotubes were grown from Fe2O3 nanoparticles supported on Ti/SiO2/Si substrates by microwave plasma chemical vapor deposition (MPCVD) under dc bias voltages of -200, -100, 0, +100, and +200 V. Electrica...

Thermoelectric recovery is promising for improved efficiency in a broad variety of combustion systems, but thermal interface resistances and the need for scalable and package-compatible thermoelectric materials is a major roadblock. We report progress on six different activities this year, which are all in support of the major goal of novel materials for thermoelectric waste-heat recovery: 1) T...

It has been more than a decade since the thermal conductivity of vertically aligned carbon nanotube (VACNT) arrays was reported possible to exceed that of the best thermal greases or phase change materials by an order of magnitude. Despite tremendous prospects as a thermal interface material (TIM), results were discouraging for practical applications. The primary reason is the large thermal con...