摘要
为了研究硅烷偶联剂改性纳米氮化铝(AlN)对有机硅弹体耐电及高温老化特性的影响,该文将纯有机硅弹体及其硅烷偶联剂改性纳米AlN复合材料在250℃高温下热老化500h,对老化前后的试样进行形貌分析、扫描电镜(SEM)断面表征、热重分析(TGA)、直流电导率及去极化电流测试、空间电荷测量、介电谱、直流击穿实验和量子化学计算,并对硅弹体基体和纳米AlN界面在老化过程中的状态变化进行分析,提出热老化前后的界面模型。结果表明:纯有机硅弹体热老化后热分解产生大量断链和内部微孔,其浅陷阱密度增加;对于纳米复合材料,老化前硅弹体基体与纳米AlN之间存在界面间隙,浅陷阱深度减小;热老化前后的界面状态对硅弹体纳米复合材料的热稳定性和电气性能产生了明显的影响,热老化后硅弹体基体与纳米AlN之间形成化学键和氢键,提高纳米复合材料的热分解温度,也使其深陷阱深度和密度增加。相比于老化后的纯有机硅弹体,老化后的纳米复合材料直流电导率更低、空间电荷积累更少、直流击穿场强明显提升,且质量分数3%纳米掺杂的复合材料具有最好的热分解抑制效果。研究结果表明,适量掺杂的硅烷偶联剂改性纳米AlN可显著提升有机硅弹体的耐电及老化特性,满足碳化硅器件封装材料长期高温应用的要求。
To study the effect of the silane coupling agent modified nano-aluminum nitride(AlN)fillers on the electrical and high-temperature aging properties of the silicone elastomer, the pure silicone elastomer and its silane coupling agent modified nanocomposites were thermally aged for 500h under 250℃. The samples before and after aging were subjected to morphology analysis, SEM cross-section characterization, thermogravimetric analysis(TGA), DC conductivity and depolarization current testing, space charge measurement, dielectric spectroscopy, DC breakdown experiment and quantum chemical calculations(QCC). The interface state variation between the silicone elastomer matrix and the nano-AlN during the thermal aging process was analyzed, and the interface models before and after thermal aging were proposed. The results show that the pure silicone elastomer produces a large number of chain scission and internal micropores after thermal aging due to thermal decomposition, and its shallow trap density increases. Before thermal aging, an interfacial gap exists between the silicone elastomer matrix and nano-AlN, decreasing the shallow trap depth. The interface state before and after aging has an obvious effect on the thermal stability and electrical properties of the silicone elastomer nanocomposites. The chemical bonds and hydrogen bonds are formed between the silicone elastomer matrix and the nano-AlN after thermal aging, which not only improves thermal decomposition temperature, but also increases deep traps depth and density. Compared with the aged pure silicone elastomer, the aged nanocomposites have lower DC conductivity, less space charge accumulation, and higher DC breakdown strength, especially, 3% nanocomposite has the best thermal decomposition inhibition effect. The results show that the silane coupling agent modified nano-AlN fillers with an appropriate doping amount can improve the electrical and aging properties of the silicone elastomer obviously, meeting the long-term high-temperature application requirement of the silicon carbide device packaging materials.
作者
陈向荣
王启隆
黄小凡
张添胤
任娜
Chen Xiangrong;Wang Qilong;Huang Xiaofan;Zhang Tianyin;Ren Na(College of Electrical Engineering Zhejiang University,Hangzhou 310027,China;Hangzhou Global Scientific and Technological Innovation Center Zhejiang University,Hangzhou 311200,China;Advanced Electrical International Research Center Zhejiang University,Haining 314400,China)
出处
《电工技术学报》
EI
CSCD
北大核心
2022年第16期4235-4249,共15页
Transactions of China Electrotechnical Society
基金
国家自然科学基金项目(52007165)
浙江省自然科学基金重点项目(LZ22E070001)
浙江大学“百人计划”项目(自然科学A类)资助。
关键词
有机硅弹体
纳米复合材料
电气性能
热老化
量子化学计算
Silicone elastomer
nanocomposites
electrical properties
thermal aging
quantum chemical calculations
