Progress in intrinsically thermal conductive liquid crystalline epoxy and composites

Difficulty in prompting heat dissipation has emerged as a critical issue and technical bottleneck restricting further miniaturization of microelectronic devices and electrical insulation equipment. Traditional heat conductive epoxy composites are not qualified for meeting the heat dissipation requirements of high-power, ultra-high-frequency and high-voltage insulating packaging because the thermal conductivity (k) and dielectric strength (E_b) cannot be regulated and improved synergistically. Intrinsically thermal conductive epoxy (ITCE), whose k can be enhanced by regulating ordered structure of cross-linked network containing liquid crystal epoxy (LCE) units, simultaneously exhibits high k and E_b. This paper analyzes the microstructure and intrinsic heat conduction mecha-nism of LCE, and summarizes the latest research progress in ITCE based on different LCE structures. The present work systematically analyzes the influencing factors on k of ITCE, such as structures of LCE and curing agent, temperature, LCE content, grain size, and external field-assisted processing, and expounds the way to improve the ordered structure of LCE and the intrinsic k. Finally, it summarizes the existing problems in current ITCE research and points to the future development direction. ITCE with excellent comprehensive performances represents the future development direction of ITCE, and the ITCE based composites has significant potential applications in high-density packaging microelectronics, high-voltage and high-power power equipment.