聚苯醚/钙镧钛微波复合基板

Polyphenylene Oxide/Ca_(0.7)La_(0.2)TiO_(3) Microwave Composite Substrate

微波复合基板兼具树脂基体的高韧性和陶瓷填料优异的介电和热学性能,是航空航天、电子对抗、5G通讯等领域的关键材料。本工作采用螺杆造粒与注塑成型相结合的新技术制备了聚苯醚(简写为PPO)为基体、钙镧钛(Ca_(0.7)La_(0.2)TiO_(3),简写为CLT)陶瓷为填料的新型微波复合基板,并对基板的显微结构、微波介电性能、热学性能和力学性能进行表征。结果表明,采用这种新技术制备的微波复合基板组成均匀且结构致密。随着CLT陶瓷的体积分数从0增大至50%,基板的介电常数从2.65提高到12.81,介电损耗从3.5×10^(–3)降低至2.0×10^(–3)(@10GHz);同时热膨胀系数从7.64×10^(–5)℃^(–1)显著降低至1.49×10^(–5)℃^(–1),热导率从0.19W·m^(–1)·K^(–1)提高至0.55W·m^(–1)·K^(–1);此外抗弯强度从97.9MPa提高至128.7MPa。填充体积分数40%CLT陶瓷的复合基板综合性能优异:ε_(r)=10.27,tanδ=2.0×10^(–3)(@10GHz),α=2.91×10^(–5)℃^(–1),λ=0.47W·m^(–1)·K^(–1),σ_(s)=128.7MPa,在航空航天、电子对抗、5G通信等领域具有良好的应用前景。

Microwave composite substrates are the key materials in the fields of aerospace,electronic countermeasure and 5G communication,etc.,as they have combined high toughness of resin matrix and excellent dielectric and thermal properties of ceramic filler.Here,a new category of microwave composite substrates with polyphenylene oxide(PPO)as matrix and Ca_(0.7)La_(0.2)TiO_(3)(CLT)ceramic as filler were prepared by a novel technology which combined screw granulating and injection molding.The microstructure,microwave dielectric properties,thermal and mechanical properties of the substrates were characterized.The results show that such microwave composite substrates prepared by this technology maintain homogeneous composition and compact structure.As volume fraction of CLTceramic increases from 0 to 50%,the dielectric constant of the substrate increases from 2.65 to 12.81 and the dielectric loss decreases from 3.5×10^(-3)to 2.0×10^(-3)(@10 GHz).Meanwhile,coefficient of thermal expansion(CTE)of the substrate significantly decreases from 7.64×10^(-5)℃^(-1)to 1.49×10^(-5)℃^(-1)and the thermal conductivity increases from 0.19W·m^(-1)·K^(-1)to 0.55W·m^(-1)·K^(-1).Additionally,bending strength of the substrate is improved from 97.9 MPa to128.7 MPa.The PPO/CLT composite substrate filling with 40%CLT(in volume)ceramic exhibits excellent properties:ε_(r)=10.27,tanδ=2.0×10^(-3)(@10GHz),α=2.91×10^(-5)℃^(-1),λ=0.47W·m^(-1)·K^(-1),σ_(s)=128.7MPa,so that it has good application prospects in aerospace,electronic countermeasure,5G communication and other fields.