Reducing thermal contact resistance using a bilayer aligned CNT thermal interface material

A thermal interface material (TIM) was fabricated by synthesizing aligned carbon nanotubes (CNT) on both sides of a thin copper foil. The Hot Disk® method was applied to measure the thermal conductivity of these CNT-TIMs. Results showed that a thicker copper foil substrate or CNT layer led to a lower overall thermal resistance. The laser flash method was used to study the performance of the bilayer aligned CNT-TIMs using two copper plates as heat source and sink. An enhancement in thermal conductivity of more than 290% could be obtained under an applied contact pressure of 0.01 MPa, as compared with two copper plates in direct contact. By filling in the space between the CNTs in the CNT layer with a conventional thermal conductive elastomer, Sylgard 160, the thermal resistance of the TIM was reduced to 8.78 mm2 K/W, a value that is better than similar devices in the literature.