He Hongying, Peng Weixiang, Liu Junbo, Chan Xin Ying, Liu Shike, Lu Li, Le Ferrand Hortense
School of Mechanical and Aerospace Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
Adv Mater. 2022 Sep;34(38):e2205120. doi: 10.1002/adma.202205120. Epub 2022 Aug 23.
Miniaturized and high-power-density 3D electronic devices pose new challenges on thermal management. Indeed, prompt heat dissipation in electrically insulating packaging is currently limited by the thermal conductivity achieved by thermal interface materials (TIMs) and by their capability to direct the heat toward heat sinks. Here, high thermal conductivity boron nitride (BN)-based composites that are able to conduct heat intentionally toward specific areas by locally orienting magnetically functionalized BN microplatelets are created using magnetically assisted slip casting. The obtained thermal conductivity along the direction of alignment is unusually high, up to 12.1 W m K , thanks to the high concentration of 62.6 vol% of BN in the composite, the low concentration in polymeric binder, and the high degree of alignment. The BN composites have a low density of 1.3 g cm , a high stiffness of 442.3 MPa, and are electrically insulating. Uniquely, the approach is demonstrated with proof-of-concept composites having locally graded orientations of BN microplatelets to direct the heat away from two vertically stacked heat sources. Rationally designing the microstructure of TIMs to direct heat strategically provides a promising solution for efficient thermal management in 3D integrated electronics.
小型化、高功率密度的3D电子设备对热管理提出了新的挑战。事实上，电绝缘封装中的快速散热目前受到热界面材料（TIMs）所实现的热导率及其将热量导向散热器能力的限制。在此，利用磁辅助注浆成型制备了高导热率的氮化硼（BN）基复合材料，该复合材料能够通过局部定向磁功能化的BN微片将热量有意地传导至特定区域。由于复合材料中BN的体积分数高达62.6%、聚合物粘合剂的浓度低以及排列程度高，沿排列方向获得的热导率异常高，高达12.1 W m⁻¹ K⁻¹。BN复合材料的密度低至1.3 g cm⁻³，刚度高至442.3 MPa，并且具有电绝缘性。独特的是，该方法通过具有BN微片局部梯度取向的概念验证复合材料得到了验证，以将热量从两个垂直堆叠的热源导出。合理设计TIMs的微观结构以策略性地引导热量，为3D集成电子中的高效热管理提供了一种很有前景的解决方案。
