Developing high-performance thermal management materials with continuous thermal conductive networks (TCN) and low interface thermal resistance (ITR) remains challenging for heat dissipation of modern electronics. Here, a multiscale BN modulation strategy for preparing dense TCN of polymer composites and decreasing simultaneously the ITR is demonstrated. As a result, the composites in this system show further thermal conductivity (κ) enhancement (25.1%) compared with single kinds of filler systems, promoting the κ of neat polymer by ∼9 times (1.957 W m⁻¹ K⁻¹), and showing a relatively high κ enhancement (∼800%). Based on the experimental and theoretical simulation results, the ITR decreased by ∼25% compared to that of conventional mixed systems, which is in accordance with κ enhancement results, indicating this method can enable efficient interconnection of fillers and dense TCNs. Meanwhile, it also presents superior dielectric properties (the dielectric constant and loss are 3.17 and 0.018, respectively.) and thermal stability (char yield is up to 72.70%, T_HRI is >269 °C.). This work provides valuable guidance for designing efficient TCN in composites and demonstrates their potential application in electronic packaging and thermal management of electronics.

开发具有连续导热网络 (TCN) 和低界面热阻 (ITR) 的高性能热管理材料对于现代电子产品的散热仍然具有挑战性。在这里，展示了一种用于制备聚合物复合材料的致密 TCN 并同时降低 ITR 的多尺度 BN 调制策略。结果，与单一种类的填料系统相比，该系统中的复合材料显示出进一步的热导率 (κ) 增强 (25.1%)，将纯聚合物的 κ 提高了 ~9 倍 (1.957 W m ^-1 K ^-1），并显示出相对较高的 κ 增强（~800％）。基于实验和理论模拟结果，与传统混合系统相比，ITR降低了~25%，这与κ增强结果一致，表明该方法可以实现填料和致密TCN的有效互连。同时，它还具有优异的介电性能（介电常数和损耗分别为 3.17 和 0.018。）和热稳定性（焦化率高达 72.70%，T _HRI大于 269 °C）。这项工作为在复合材料中设计高效的 TCN 提供了有价值的指导，并展示了它们在电子封装和电子热管理中的潜在应用。