高压ZnO厚膜压敏电阻的制备及导电机理分析  

Preparation of High Voltage ZnO-Based Thick Film Varistors and Conductive Mechanism Analysis

作　　者：柯磊[1] 李桃 

机构地区：[1]上海电机学院数理教学部,上海200240 [2]上海金仕达卫宁软件股份有限公司HIS开发部,上海200436

出　　处：《上海电机学院学报》2011年第3期157-162,共6页Journal of Shanghai Dianji University

基　　金：国家自然科学基金项目资助(10804071);上海市高校选拔培养优秀青年教师科研专项基金项目资助(sdj11010);上海电机学院科研启动经费项目资助(11C409)

摘　　要：通过高能球磨、丝网印刷和低温烧结制备出高压ZnO厚膜压敏电阻,并对厚膜试样进行了电学性能、物相成分和微观形貌的表征。结果表明:厚膜试样电位梯度达到3 159.4 V/mm,漏电流为36.4μA,非线性系数为13.1,平均晶粒尺寸为1.29μm。高能球磨和低温烧结使厚膜试样的晶粒尺寸大大减小,有效提高了电位梯度值。分析了厚膜压敏电阻单晶界体系的导电机理,发现预击穿区势垒宽度的增加和单晶界电压的提高对其非线性性能以及压敏电压的提升影响明显,决定了压敏电阻的电学特性。High voltage ZnO-based thick film varistors were prepared by high-energy ball milling,screen printing and low-temperature sintering.Electrical properties,phase composition and microstructure of the thick film samples were investigated.Experimental results showed that voltage gradient reached 3159.4V/mm.Leakage current,nonlinear exponent and average grain size were 36.4μA,13.1,and 1.29μm,respectively.The notable decrease of grain size after high-energy ball milling and low-temperature sintering is the reason of voltage gradient increase.The conductive mechanism of single grain boundary system is analyzed.The increase of barrier width and single grain boundary voltage in the pre-breakdown region can enhance the nonlinear exponent and voltage gradient,which determines the electrical properties of thick film varistors.

关 键 词：厚膜压敏电阻 电位梯度 导电机理 

分 类 号：TM283[一般工业技术—材料科学与工程]