粉体颗粒细度对多层片式氧化锌压敏电阻器性能的影响

The Effect of ZnO Powder Particle Distribution on Performance of Multilayer Chip Varistor

通过调整 Bi_2O_3、Sb_2O_3、TiO_2、B_2O_3、BaCO_3等少量添加剂的掺量,可在低温880℃下与10%Pd-90%Ag内电极共烧,制得性能优良的多层片式氧化锌压敏电阻器(ZnO MLCV)。主要采用两种不同颗粒细度的 ZnO 粉体来研究粉体颗粒细度对多层片式氧化锌压敏电阻器性能的影响。研究发现适当地使用部分超细 ZnO 粉体,改善 ZnO 粉体的颗粒分布,再使用适量的磷酸酯作为分散剂,可以流延制得较致密、平整、均匀的膜片,从而制得瓷体的致密性较高,且非线性系数较高、漏电流较低、峰值电流及能量耐量较高的多层片式压敏电阻器;而 ZnO 粉体颗粒粒径太大及过细,都会影响膜片的质量,进而影响多层片式压敏电阻器的性能。XRD 衍射分析发现 ZnO 粉体颗粒细度的改变对瓷体的物相组成无明显影响。

Adjustment of the amount of Bi_2O_3,Sb_2O_3,TiO_2,B_2O_3,BaCO_3 can decrease the firing temperature of ZnO varistor.The low firing multilayer chip varistor(MLCV)with high properties can be manufactured by being co-fired with 10% Pd-90% Ag internal electrodes at 880℃.The effect of ZnO powder particle size distribution on MLCV electric performance is studied.The result shows adding proper amount of super fine ZnO powder can improve the composite powder particle size distribution,and high performance slurry can be prepared by using phosphate as dispersant.Compact,smooth and homogeneous green tapes can be made by casting the slurry.Using these green tapes,high performance MLCV with low leakage current,big nonohmic coefficient,high peak current and maximum surge energy is manufactured.Too big or too small ZnO particle size would affect the quality of green tapes,thereffore,affect the performance of MLCV.XRD analysis indicates that the difference of ZnO particle distribution does not influence the crystal phase of the ceramic obviously.