Carbon nanotube films bonding enhanced with magnetic field

Vertically aligned carbon nanotube films are good thermal interface materials because of their high thermal conductance and mechanical compliance. In this study, the authors bond carbon nanotube films and metallized silicon chips together using thermocompression method in a magnetic field to decrease the thermal contact resistance between them. Nickel is considered as the deposition metal because of its strong cohesion and good affinity on the carbon nanotube surface and it is ferromagnetic in nature. Bonding is demonstrated in vacuum chamber under the influence of temperature (300°C) and pressure (180 KPa). The resistance of the carbon nanotube film is measured with a thermal transient tester that can provide the structure function of the sample, so that people can know detailed thermal resistance. In general, the thermal contact resistance of the sample enhanced with magnetic field that the author measured is 34·24 mm²K/W that is 10% lower than the sample without enhancement. This study reveals that magnetic field can enhance the bonding strength to decrease the thermal contact resistance.