Parallel Structure Enhanced Polysilylaryl-enyne/Ca_0.9La_0.067TiO₃ Composites with Ultra-High Dielectric Constant and Thermal Conductivity

Abstract

With the rapid development of the microwave communication industry, microwave dielectric materials have been widely studied as the medium of signal transmission. Nowadays, with the increase in communication frequency, devices are miniaturized, and dielectric materials are required to have higher dielectric constants. At the same time, the miniaturization of devices brings about an increase in power density, which puts forward higher requirements for the thermal conductivity of materials. In this work, polysilylaryl-enyne (PSAE) and Ca 0.9 La 0.067 TiO 3 (CLT) were chosen as the matrix and filler, respectively, to construct a parallel model composite through a freeze casting method and a 0−3 model composite through the direct mixing method, respectively. After comparing the microstructures of the two models, their dielectric properties and thermal conductivity were measured and simulated. The parallel model composites in the stable range possess uniform parallel structures, and the solid content limit for them could be as high as 73.2%, which is much higher than that of the 0−3 model composites. While the 0−3 model composite possesses an optimal dielectric constant of 25.4 (@10 GHz) and a thermal conductivity of 0.965 W•m −1 •K −1 , the parallel model composite possesses a 2 times higher dielectric constant of 76.2 (@10 GHz) and a 1 times higher thermal conductivity of 2.095 W•m −1 •K −1 . Since the parallel model composite possesses much higher dielectric constant and thermal conductivity than traditional 0−3 model composites, it can be an excellent candidate for microwave communication.

Tunable Microwave Dielectric Properties in Rare-Earth Niobates via a High-Entropy Configuration Strategy To Induce Ferroelastic Phase Transition

“…Thermal conductivity is an essential feature for electronic packages and devices with dielectric substrates. 47,48 The thermal conductivity of 0.1−0.4 V ceramics at room temperature, as shown in Figure 12, demonstrates a general increase with the addition of V dopants, ranging from 2.13 W/(m•K) for 0.1 V to 2.96 W/(m•K) for 0.4 V. These values are comparable to those of single-element LnNbO 4 ceramics (2.4−3.5 W/(m•K)), 49 suggesting that the high-entropy design has minimal impact on thermal conductivity.…”