The low dielectric polymer films have drawn great attention to the application as the dielectric insulating materials in high-frequency circuit boards, while the weak adhesion to the copper foils and the poor processability resulted from the fluorinated or rigid structures limited their high-frequency application. In this work, the low dielectric and high adhesive polyimide/fluorinated ethylene propylene (PI/FEP) nanocomposite film for high-frequency flexible circuit board application is developed. It is indicated that the fluorocarbon surfactants can significantly improve the dispersion of FEP in PI substrate, and thus, the PI/FEP nanocomposite film exhibits excellent mechanical properties, including the tensile strength increases to 46.6 MPa and the elongation at the break increases to 13.7%. Importantly, at the high-frequency of 10 GHz, the 60 wt% FEP filled PI nanocomposite film displays an ultralow dielectric loss (0.006) and a reduced dielectric constant (2.69). In addition, the high-frequency flexible circuit board with the PI/FEP film as the dielectric insulating layer has a high peel strength of 0.75 N mm −1 , indicating this PI/FEP nanocomposite film can meet the requirements of the high-frequency flexible circuit board application.
The composites reported here were prepared through a melt-rolling mixing process, in which surface passivated multi-wall carbon nanotube and poly(vinylidene fluoride) were used as the filler and the matrix, respectively. X-ray diffraction, precision inductance-capacitance-resistance, and laser flash thermal-diffusivity analyses were employed to characterise the structural, electrical and thermal properties. Results indicate that through the surface passivation of carbon nanotubes, the electrical resistivities of the composites were greatly enhanced, while the thermal conductivities do not change significantly. The electrical properties were discussed in comparison with the Maxwell-Wagner polarisation, universal law, and Gerhardt's method.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.