Ultra-low dielectric constant fluorinated graphene/polybenzoxazole composite films with excellent thermal stabilities and mechanical properties

Abstract

Unsatisfied dielectric properties and inferior mechanical properties have become the main obstacles limiting the application of polybenzoxazole (PBO) in the field of microelectronics. Herein, a novel nanocomposite film was successfully developed by introducing fluorinated graphene (FG) into fluorinated PBO (FPBO). Interestingly, the FG/FPBO composite films showed an ultra-low dielectric constant of 2.02 at 1 MHz. Meanwhile, the tensile strength of the composite films increased up to 103.5 MPa, which was 25% higher than that of the pristine FPBO. Moreover, the 5% weight loss temperature of FG/FPBO composites were as high as 525 °C, displayed an outstanding heat resistance. The water absorption of FG/FPBO films have also dropped from 1% to 0.5% due to the high hydrophobicity of FG. In short, our work provides a simple and efficient approach for the preparation of high-performance films with low dielectric constant and water absorption, as well as high mechanical strength and thermal stability.