Polycarbonate (PC) is an engineering thermoplastic with excellent insulation and mechanical properties. However, the low thermal conductivity restricted its application in electronic devices. Hexagonal boron nitride (h-BN) microparticle, a promising material with high thermal conductivity, was functionalized with cationic polyacrylamide (CPAM) and introduced into PC matrix to improve the thermal conductivity. SEM and XRD analysis showed that the modified BN (CBN) particles oriented and formed thermal conductive pathways within PC matrix. The formation of large-area oriented CBN significantly improved the thermal conductivity and thermal stability of composites. At 20 wt % CBN loading, the thermal conductivity of 0.7341 Wm(-1) K-1 and the temperature for 5% weight loss (T-5) of 498.6 degrees C were obtained, which was 3.1 times and 77 degrees C higher than that of pure PC, respectively. Furthermore, outstanding electrical insulation property of matrix was retained in the composites. These results revealed that PC/CBN composite was a promising material for thermal management and electrical enclosure. (C) 2017 Wiley Periodicals, Inc.