环氧树脂的等离子体表面梯度刻蚀及沿面闪络性能研究

Effect of plasma surface gradient etching on surface flashover performance of epoxy resin

结合等离子体表面刻蚀方法与梯度改性方法,实现了氧化铝/环氧树脂表面的等离子体梯度刻蚀。利用扫描电子显微镜(SEM)、表面轮廓仪、X射线光电子能谱分析(XPS)、高阻计、闪络电压和表面电位测试系统,对比了未处理、等离子体均匀刻蚀、等离子体梯度刻蚀三种情况的样片表面形貌、化学元素和电气参数,研究了等离子体梯度刻蚀对沿面闪络性能的提升机理。结果表明,等离子体表面刻蚀可提升环氧树脂表面粗糙度、提高样片表面电导率、浅化陷阱能级以及提升沿面闪络电压。等离子体梯度刻蚀对闪络电压的提升效果要优于等离子体均匀刻蚀,相比于未处理样片最大可提升26.5%。分析认为针-针电极的电场分布可划分为三结合点处附近的高场强区和电极之间的低场强区,加快高场强区的表面电荷消散速率并适当控制低场强区表面电荷迁移速率,可以最大程度地提升样片整体的沿面闪络性能。

In this paper,plasma gradient etching of alumina/epoxy resin surface is realized by combining plasma surface etching method and gradient modification method.Scanning electron microscope(SEM),surface profiler,X-ray photoelectron spectroscopy(XPS),high resistance meter,flashover voltage and surface potential measurement system were used to compare the surface morphology,chemical elements and electrical parameters of untreated,uniform plasma etching and gradient plasma etching samples,and the mechanism of improving the surface flashover performance by gradient plasma etching was studied.The results show that plasma surface etching can improve the surface roughness of epoxy resin,increase the surface conductivity,shallow the trap energy level and increase the surface flashover voltage.The enhancement of flashover voltage by plasma gradient etching is better than that by plasma uniform etching,and the maximum increase is 26.5%compared with the untreated sample.The analysis shows that the electric field distribution of the needle-needle electrodes can be separated into the high field intensity region(near the triple junction)and the low field intensity region(between the electrodes).Speeding up the surface charge dissipation rate in the high field intensity region and properly controlling the surface charge migration rate in the low field intensity region can improve the overall surface flashover performance of the sample to the greatest extent.