【摘要】 传统热固性树脂耐热性较差，限制了一体成型电感器在高温工况下的应用.使用聚酰亚胺改性环氧树脂作为有机包覆材料制备了3组磁粉芯材料，并以1组环氧树脂包覆磁粉芯作为对照进行实验.结果表明，聚酰亚胺改性环氧树脂显示出了良好的包覆均匀性，显著提高了羰基铁粉的耐高温氧化性能.与环氧树脂相比，聚酰亚胺改性环氧树脂具有与铁粉更接近的线膨胀系数，玻璃化转变温度可达177℃,采用3%聚酰亚胺改性环氧树脂制备的磁环径向断裂强度高达398 N,在240℃条件下仍能保持50 GΩ以上电阻，3次265℃高温回流焊后材料内部结构稳定，电感仅降低2.70%.更多还原

【Abstract】 The poor heat resistance of traditional thermosetting resins limits the application of molded inductors in high temperature conditions. Three groups of magnetic powder core materials are prepared using polyimide-modified epoxy resin as organic coating material, and one group of epoxy resin coated magnetic powder core is used as a control to conduct experiments. The results show that the polyimide-modified epoxy resin has good coating uniformity and significantly improves the high temperature oxidation resistance of carbonyl iron powder. Compared with the epoxy resin, the polyimide-modified epoxy resin has a linear expansion coefficient closer to that of the iron powder, and the glass transition temperature is up to 177 ℃. The radial breaking strength of the magnetic ring prepared by 3% polyimide-modified epoxy resin is as high as 398 N, and the resistance is still above 50 GΩ at 240 ℃. After reflow welding at 265 ℃ for three times, the internal structure of the material is stable, and the inductance is only reduced by 2.70%.更多还原