Abstract A 3D filler network structure can significantly improve the thermal conductivity of a composite. In addition, a spherically shaped filler is advantageous for high packing density and filler connectivity compared to other shapes. Here, to achieve a high thermal conductivity, epoxy composites were fabricated using spherically aggregated boron nitride (A-BN) and Cu foam as hybrid fillers. To defoam the composites, A-BN was first incorporated into the matrix with Cu foam by a vacuum impregnation process, followed by a curing process. As the A-BN loading increased up to 25 wt%, the thermal conductivity of the composite also increased due to the formation of a heat path. However, when the filler loading exceeded 25 wt%, the thermal conductivity decreases because of filler aggregation. Thus, the composite containing 25 wt% A-BN exhibited the maximum thermal conductivity (2.017 W/mK), with an enhancement of 940% compared with that without filler. In addition, the incorporation of A-BN is beneficial for increasing the volume resistivity of the composite, allowing its practically insulation (1.21 × 1013 Ω cm). This study shows that the formation of 3D network structures with binary fillers is advantageous for the heat management of electronic devices.

中文翻译：

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导热3D双网络结构聚合氮化硼/铜泡沫/聚合物复合材料

摘要 3D 填料网络结构可以显着提高复合材料的热导率。此外，与其他形状相比，球形填料有利于高填充密度和填料连通性。在这里，为了实现高导热性，使用球形聚集的氮化硼 (A-BN) 和 Cu 泡沫作为混合填料制造了环氧树脂复合材料。为了使复合材料消泡，首先通过真空浸渍工艺将 A-BN 与 Cu 泡沫结合到基体中，然后进行固化工艺。随着 A-BN 负载量增加至 25 wt%，复合材料的热导率也因热路径的形成而增加。然而，当填充量超过 25 wt% 时，由于填料聚集，热导率下降。因此，含有 25 wt% A-BN 的复合材料表现出最大的热导率 (2.017 W/mK)，与不含填料的复合材料相比提高了 940%。此外，A-BN 的掺入有利于提高复合材料的体积电阻率，使其实际上绝缘（1.21 × 1013 Ω cm）。该研究表明，具有二元填料的 3D 网络结构的形成有利于电子设备的热管理。