采用差示扫描量热分析法,研究了印制电路板(PCB)绝缘层树脂——感光改性环氧树脂预固化体系中固化剂2123型酚醛树脂和固化促进剂咪唑的合适配比。利用硅烷偶联剂对纳米SiO_2进行表面处理制得亲油性纳米SiO_2,将其掺入到感光改性树脂固化体系中以提高体系的热稳定性能。采用正交实验和单因素实验方法,研究了亲油性纳米SiO_2用量、固化最高温度、最高温度固化时间3个因素对该树脂体系固化产物在200℃的热降解量的影响。结果表明,感光改性环氧树脂/2123型酚醛树脂/咪唑最佳质量比为100/5/1.5,此时的固化反应最为完全;在掺杂纳米SiO_2的感光改性树脂的最佳固化工艺条件下,即当亲油性纳米SiO_2质量分数为5%,固化最高温度为120℃,最高温度固化时间为2 h时,固化产物的200℃热降解量为0.94%。 The suitable ratio of curing agent 2123 phenolic resin and curing accelerator imidazole in the pre-curing system of PCB insulating layer resin-photo-modified epoxy resin was studied by differential scanning calorimetry. The nanosilica was surface-treated with a silane coupling agent to obtain the lipophilic nano-SiO 2, which was incorporated into the photosensitive resin curing system to improve the thermal stability of the system. The effects of the amount of lipophilic nano-SiO 2, the highest curing temperature and the highest curing temperature on the thermal degradation of the cured resin product at 200 ℃ were studied by orthogonal and single-factor experiments. The results showed that the best curing reaction of photosensitive modified epoxy resin / 2123 phenolic resin / imidazole was 100/5 / 1.5, and the curing reaction was the most complete. When the lipophilic nano-SiO 2 mass fraction is 5%, the highest curing temperature is 120 ℃ and the highest curing temperature is 2 h, the thermal degradation of the cured product at 200 ℃ is 0.94%.