AlN表面处理及级配填充对覆铜板绝缘层性能的影响规律与机制研究

在覆铜板绝缘层基体中添加导热陶瓷填料是提高其导热性能的一种有效方法。AlN是一种导热率高、绝缘性好的陶瓷填料, 但其易水解的性质限制了实际应用。此外, 相比于陶瓷填料-树脂基体复合材料体系, 有关填料填充型覆铜板产品性能的系统研究较少。本研究通过对AlN进行磷酸酸洗, 获得了抗水解性能优异的pAlN, 进一步研究了不同pAlN粒径和填充量对覆铜板导热性、剥离强度、介电性能和其他性能的影响。为了获得更有效的填料分布网络, 采取了不同粒径pAlN级配填充策略, 探究了多种级配方案对覆铜板性能的影响, 获得了最优级配和综合性能优异的覆铜板。在最优级配为pAlN-50 μm60%-5 μm5%时, 覆铜板绝缘层的热导率增大至0.757 W/(m·K), 相比纯树脂覆铜板提高160%, 具有优异的力学性能(剥离强度为1.012 N/mm, 弯曲强度为335 MPa)和介电性能(介电常数为4.499, 介电损耗为6.668×10^-3), 同时吸水率低至0.53%。同时探讨了AlN填料在覆铜板应用中存在的问题和解决方法, 系统研究了不同填充方案对覆铜板绝缘层性能的影响, 对其实际应用具有指导意义。

Effect and Mechanism of the Surface Treatment and Gradation Filling of AlN on the Performance of Insulation Layer of Copper Clad Laminate

Introducing thermally conductive ceramic fillers to the copper clad laminate (CCL) resin matrix is an effective way to improve its thermal conductivity. AlN is a kind of ceramic filler with high thermal conductivity and good insulation, but its easy hydrolysis has limited its practical application. In addition, compared with the ceramic filler-resin matrix composite system, systematic research on the properties of the filler filled CCL is relatively rare. In this study, AlN was treated with phosphoric acid to obtain pAlN with excellent hydrolysis resistance. Then, the effects of different pAlN particle sizes and filling amount on the thermal conductivity, peeling strength, dielectric properties and other properties of AlN-filled CCLs were investigated. Finally, the pAlN gradation filling strategy of different particle sizes was adopted to explore the influence of different gradation schemes on the performance of the CCLs, of which the CCL with the best gradation and excellent comprehensive performance was obtained. The results show that the thermal conductivity of CCL insulating layer increases to 0.757 W/(m·K), 160% higher than that of pure resin CCL under the optimal gradation of pAlN-50 μm60%-5 μm5%. It displays excellent mechanical properties ( peel strength of 1.012 N/mm and bending strength of 335 MPa), dielectric properties (dielectric constant of 4.499 and dielectric loss of 6.668×10^-3), and the water absorption which is as low as 0.53%. All these data could be a promising guidence for CCL application.