氧化物阴极表面Ag污染对三极管成品率影响研究  

Effect of Surface Ag Pollution of Oxide Cathode on Triode Yield

作　　者：张敏[1] 王秉直 张珂[1] ZHANG Min;WANG Bing-zhi;ZHANG Ke(Beijing Vacuum Electronics Research Institute,Beijing 100015,China)

机构地区：[1]北京真空电子技术研究所,北京100015

出　　处：《真空电子技术》2023年第4期50-53,共4页Vacuum Electronics

摘　　要：针对钛陶瓷三极管成品率偏低的问题,本文利用能量色散谱仪对钛陶瓷三极管样品阴极表面成分进行分析,发现原封接工艺制备的三极管用氧化物阴极表面被一定量的Ag污染。根据排气封接工艺判断出阴极表面沉积的Ag来自于Ag-Cu焊料,通过模型计算安全保温时间,优化了排气分解保温时间。根据优化排气封接工艺制备的三极管内阴极表面未检测出Ag成分;将该阴极和被Ag污染的阴极放入二极管进行发射性能测试,结果显示被Ag污染的阴极和未被Ag污染的阴极拐点电流密度在800℃时分别为3和11 A/cm^(2),优化排气封接工艺制备的三极管成品率由原来的30%提高至80%。Against the low yield of titanium ceramic triodes,energy dispersion spectrometer(EDS)is employed to analyze the chemical element of the cathode surface.It is found that the oxide cathode surface of the triode prepared by original sealing process is contaminated by a certain amount of Ag.Considering the exhaust sealing process,it is concluded that the Ag deposited on cathode surface comes from the Ag-Cu solder.The exhaust holding time of the exhaust sealing process is optimized through the model calculation of safe holding time,and no Ag is detected on the cathode surface in the triode prepared by the optimized exhaust sealing process.The cathodes with and without Ag contamination are placed in diodes for emission performance test,and the knee point current densities of them at 800℃ are 3 and 11 A/cm^(2) respectively.The yield of the triode prepared by the optimized exhaust sealing process increases from 30% to 80%.

关 键 词：氧化物阴极 排气封接 电流密度 安全保温时间 

分 类 号：TN103[电子电信—物理电子学]