Dual-Effect Coupling for Superior Dielectric and Thermal Conductivity of Polyimide Composite Films Featuring "Crystal-Like Phase" Structure

To match the increasing miniaturization and integration of electronic devices, higher requirements are put on the dielectric and thermal properties of the dielectrics to overcome the problems of delayed signal transmission and heat accumulation. Here, a 3D porous thermal conductivity network is successfully constructed inside the polyimide (PI) matrix by the combination of ionic liquids (IL) and calcium fluoride (CaF2) nanofillers, motivated by the bubble-hole forming orientation force. Benefiting from the 3D thermal network formed by IL as a porogenic template and "crystal-like phase" structures induced by CaF2- polyamide acid charge transfer, IL-10 vol% CaF2/PI porous film exhibits a low permittivity of 2.14 and a thermal conductivity of 7.22 W m-1 K-1. This design strategy breaks the bottleneck that low permittivity and high thermal conductivity in microelectronic systems are difficult to be jointly controlled, and provides a feasible solution for the development of intelligent microelectronics. Through the dual action of calcium fluoride and ionic liquid on the polyimide (PI) matrix, the 3D porous thermal conductivity network and special "crystal-like phase" structures are constructed in PI. These endow the PI materials with highly efficient low dielectric and thermal conductivity properties to better serve the electrical and electronic fields.image