Palladium Thiolate Bonding of Carbon Nanotube Thermal Interfaces

Carbon nanotube (CNT) arrays can be effective thermal interface materials with high compliance and conductance over a wide temperature range. Here, we study CNT interface structures in which free CNT ends are bonded using Pd hexadecanethiolate, Pd(SC(16)H(35))(2), to an opposing substrate (one-sided interface) or opposing CNT array (two-sided interface) to enhance contact conductance while maintaining a compliant joint. The Pd weld is particularly attractive for its mechanical stability at high temperatures. A transient photoacoustic (PA) method is used to measure the thermal resistance of the palladium-bonded CNT interfaces. The interfaces were bonded at moderate pressures and then tested at 34 kPa using the PA technique. At an interface temperature of approximately 250 degrees C, one-sided and two-sided palladium-bonded interfaces achieved thermal resistances near 10 mm(2) K/W and 5 mm(2) K/W, respectively. [DOI: 10.1115/1.4004094]