2018 Volume 59 Issue 8 Pages 1251-1258
Power modules, particularly in hybrid and electric vehicles, have become an essential part of their thermal management system design. In power cooling modules, the temperature variations are important issues, leading to thermal stresses caused by different coefficients of thermal expansion (CTE) in the composite materials. Thus, one should consider suitable materials and manufacturing processes to achieve the best performance and reliability during the device’s life cycle. The Cu/CNT-Cu material is assumed to have a unique combination of a high thermal conductivity and low coefficient of thermal expansion, which results in a new composite material that goes beyond the ability of regular materials. To address this, we have developed the Cu/CNT-Cu composite with a significant improvement in thermal conductivity (∼327 W/mK) which is within the industrial scale range of copper metal injection molding (320–340 W/mK) and low coefficient of thermal expansion (∼6 ppm/K), both of which make it an excellent choice for power modules in next generation automobiles. This was achieved by reducing the voids and increasing the interface bonding while adding the copper coated CNTs, which were made by an electroplating process. This mixed Cu/CNT-Cu property makes it the top material design selection in the Ashby map and has a better temperature stability due to its lower thermal distortion parameter (TDP). As a result, this material will represent a significant scientific and technological development in the advancement cooling of IGBT power module devices.
