含ZnO的TiO_(2)压敏器件的失效分析

Failure analysis of TiO2 varistor devices containing ZnO

氧化锌掺杂的氧化钛压敏陶瓷器件经烧结后,观察到器件表面发生氧化锌析出和氧化锌晶须的形成,导致器件功能失效。经过深入分析,这一问题的根本原因在于烧结炉壁表面沉积的碳颗粒脱落并附着在陶瓷器件表面,形成了一处还原性气氛。这一还原性气氛对氧化锌产生了影响,将其还原为液态锌,随后液态锌上浮到陶瓷器件表面,再次氧化,形成氧化锌的暗斑。随着液态锌的蒸发,它重新氧化,并在氧化锌晶核上有序生长,最终形成了氧化锌晶须。这一结果有助于深化对含氧化锌压敏陶瓷器件的失效行为理解。

When zinc oxide is doped into oxide titanium varistor ceramic devices and subjected to sintering,the observation reveals the precipitation of zinc oxide and the formation of zinc oxide whiskers on the surface of the device,leading to failure of the device.With in-depth analysis,we have concluded that the fundamental cause of this issue is that the carbon particles deposited on the sintering furnace wall fell off and then adhered to the surface of the ceramic device,resulting in reducing atmosphere in that specific area.This reducing atmosphere has induced the reduction of the zinc oxide into liquid zinc,which subsequently rise up to the surface of the ceramic device and re-oxidized into dark zinc oxide spots.With the evaporation and re-oxidation of the liquid zinc,selectively grows on the zinc oxide nuclei happened and formed zinc oxide whiskers.This result contributes to a deeper understanding of the failure behavior in ceramic devices containing zinc oxide.