Thermal management of electronics is a great challenge to achieve optimum performance. Nano materials provide a pathway to increase thermal conductivity but nano particles uniform dispersion in the matrix is very difficult. This study focuses on dispersion of functionalized multi-walled carbon nano tubes in copper to improve thermal conductivity of copper. Copper/Carbon Nano Tubes (CNTs) composites were developed via powder injection moulding. Feedstock was compounded using Z-blade mixer and defect free green parts were produced by injection moulding. Binder was removed by solvent and thermal means followed by sintering in argon at 1050 �. Thermal conductivity and reliability tests were performed on sintered nano composite specimen at various temperatures. Results showed good dispersion of CNTs in copper and thermal conductivity measured was 550�580 w/m.k. A decrease of 27�37 in thermal conductivity was recorded during thermal cycling of sintered composite and the reduced thermal conductivity value is still 80 higher than pure copper. © 2020, Springer Nature Singapore Pte Ltd.