纳米金属Ag/高纯聚酯改性硅漆复合介质的介电行为  

Dielectric Behavior of Nano Metal Ag/Ultra-Pure Silicone Resin Modified Polyester Composite

作　　者：董小兵[1] 徐传骧[2] 江秀臣[1] 

机构地区：[1]上海交通大学电气工程系,上海200030 [2]西安交通大学电气绝缘研究中心,西安710049

出　　处：《电工技术学报》2006年第4期20-23,61,共5页Transactions of China Electrotechnical Society

摘　　要：聚酯改性硅漆(SP)是用于硅器件表面保护的高纯绝缘材料。采用溶胶法制备的纳米Ag(直径小于20nm)均匀地分散到SP中后,对纳米复合材料的介电特性进行了研究。合适的纳米Ag含量使得纳米复合材料击穿场强提高,达到纯SP的112%,同时介电损耗也明显增加。采用热刺激退极化电流(TSDC)测量的结果表明纳米复合材料中存在两个较浅的陷阱能级,分别为0.52eV和0.62eV,陷阱密度分别为1.2×1010/cm3和2.0×1011/cm3,与纯SP中浅陷阱深度0.58eV、陷阱密度3.1×1010/cm3明显不同。复合材料低温下(77K)的体积电阻率明显高于纯SP,可以看作是库仑阻塞作用的结果。从介质物理的角度探讨了纳米复合材料与纯SP的特性差别。Silicone resin modified polyester（SP） is a kind of ultra-pure surface protection material used in semiconductor device. Nano-Ag （diameter less than 20 nm） is successfully made from Ag colloidal sol and homogeneously dispersed into SP, and the dielectric characteristics of the composite are studied carefully. The breakdown voltage of the composite can be improved with appropriate nano-Ag content, which increases to 112% of that of pure SP, while the dielectric loss also increases obviously. Thermally stimulated depolarization current （TSDC） results indicate that there are two types of shallow traps in the composite, 0.52eV and 0.62eV with trap densities 1.2×10^10/cm^3 and 2.0×10^11/cm^3, which differs significantly from that of pure SP （0.58eV, 3.1×10^10/cm^3）. Resistivity of the composite is much greater than that of pure SP under cryogenic temperature （77K）, which is called Coulomb Blockade Effect. From the view of dielectric physics, the different characteristics between the composite and pure SP are discussed.

关 键 词：纳米复合材料 聚酯改性硅漆 介电特性 热刺激退极化电流 

分 类 号：TM201.3[一般工业技术—材料科学与工程] TB383[电气工程—电工理论与新技术]