Functionalized Al2O3 fillers/glass fibers cloth/PTFE composites with excellent thermal properties

• Published in: Journal of materials science. Materials in electronics Vol. 33; no. 11; pp. 8815 - 8821
• Main Authors: Tan, Youhong, Liu, Yangfu, Yan, Xueyu, Lu, Guanyu, Xie, Kainan, Tong, Jianxi, Meng, Fancheng
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.04.2022; Springer Nature B.V
• Subjects: Aluminum oxide; Characterization and Evaluation of Materials; Chemistry and Materials Science; Cloth; Composite materials; Dielectric loss; Flexural strength; Glass fiber reinforced plastics; Heat conductivity; Heat transfer; Hot pressing; Materials Science; Mechanical properties; Optical and Electronic Materials; Permittivity; Polytetrafluoroethylene; Substrates; Thermal conductivity; Thermal expansion; Thermodynamic properties; Water absorption
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-021-06897-0

The alumina/glass fibers cloth/polytetrafluoroethylene composites were prepared by blending impregnation followed by hot compression method, and the dielectric, thermal, and mechanical properties of the composites with various Al 2 O 3 contents (15–40 wt%) were investigated. The results show that the thermal conductivity and dielectric constant of the composites increase gradually, while the coefficient of thermal expansion decreases, with the Al 2 O 3 content increasing. Composite substrates with 40 wt% Al 2 O 3 exhibited ideal performance, which have reliable dielectric constant (ε r  = 3.49), admissible dielectric loss (tanδ = 0.0027), low water absorption (0.04 %), low CTE of 8.73, 10.14 and 110.39 ppm/°C (X-, Y-, Z-direction, respectively), relatively high thermal conductivity (0.61 W m −1  K −1 ), and satisfactory flexural strength (66.1 MPa). Such compositions may be a promising material in high-frequency microwave substrates.