Journal Article

Improved properties of PTFE composites filled with glass fiber modified by sol–gel method

Liu, Pengying, Mahmood, Kashif, Li, Qiuying, Che, Yanchao, Zhang, Ning

2021

Overview

PTFE/GF(glass fiber) composites are widely applied in high-frequency printed circuit board (PCB) substrate materials due to the excellent dielectric properties of PTFE and the low thermal expansion coefficient of GF. However, the poor interface compatibility between PTFE and GF affects the performance of the composite substrates. In this study, tetraethyl orthosilicate (TEOS) was used as the silicon source, and polydimethylsiloxane (PDMS) was the organic precursor to modify the surface of GF through the sol–gel method to promote the interface compatibility of GF and PTFE. The modified GF noted T-GF was filled in PTFE to prepare PTFE/T-GF composites. SEM, FTIR, XPS, and contact angle confirmed that organic–inorganic hybrids were successfully loaded on GF's surface. Moreover, compared with PTFE/GF and the conventional coupling agent modified GF filled PTFE composites, the PTFE/T-GF exhibited improved dielectric constant (2.305), decreased dielectric loss (9.08E −4 ), higher bending strength (21.45 MPa) and bending modulus (522 MPa), better thermal conductivity (0.268 W/m*K) and lower CTE (70 ppm/°C), making it has promising application as the substrate materials for high frequency PCB.

• Publisher: Springer US,Springer Nature B.V
• Subject: Bend strength / Bending modulus / Characterization and Evaluation of Materials / Chemistry and Materials Science / Circuit boards / Compatibility / Composite materials / Contact angle / Coupling agents / Dielectric loss / Dielectric properties / Dielectric strength / Glass fibers / Materials Science / Optical and Electronic Materials / Polydimethylsiloxane / Polytetrafluoroethylene / Printed circuits / Sol-gel processes / Substrates / Tetraethyl orthosilicate / Thermal conductivity / Thermal expansion / X ray photoelectron spectroscopy