A novel TFEL device using a high-dielectric-constant multilayer ceramic substrate

A novel composite-structure ac EL device using thin films and a ceramic substrate has been developed. A light-emitting thin film (ZnS:Mn) and ITO electrodes are deposited on a multilayer ceramic substrate consisting of a very high-dielectric ceramic insulating layer (ε
s
∼ 10
⁴
), internal printed electrodes, and a ceramic base plate. This device features low operating voltage (40-80 V), breakdown-failure-free operation, and high legibility.