Studies On TFEL Device Using Ceramic Thick Film As Insulator Layer

Nowadays, we have entered the information age, information display is an important part of Information Technology, it is the interface of human beings and the machine. Flat Panel Display is the basic requirement of the terminal display in the information age. Ceramic Thick Film Electro-Luminescence Display as a branch of Flat Panel Display re-present the good quality which CRT presents. CTFELD using inorganic materials shows the following merit: all-solidified, low operating voltage, wide visual angle, high resolution, fast response, good reliability. It is an ideal FPD, compared with LCD, it need no back-light, brighter, response faster; compared with CRT, it is more efficient, has wider visual angle; compared with PDP, it is cheaper, longer lived. It has a bright future on the scientific apparatus, portable computer, Aeronautics and military field.This dissertation describes how to manufacture the high-dielectric ceramic-insulted Thick-Film ac EL device(a TDEL device). This dissertation mainly introduces the emitting mechanism ,the importance of insulator layer to the EL device and the TDEL device manufacturing technics. The Internal electrodes are printed on a glass substrate. The insulator layer is fabricated by green sheet laminationg technology. A slurry, consisting of cramic powder(a complex Perovskite compound system {Pb(Ni1/3Nb2/3)O3-Pb(Mg1/2W1/2)O3-PbTiO3}, developed for low-firing and high dielectric constant multilayer ceramic capacitor) and organic vehicles, is cast into thin ceramic green sheets(10-80μm thick). Then these sheets are laminated and fired at a sintering temperature of 900oC-1000oC. Vacuum-evaporated emitting thin film are deposited on the ceramic substrate surface. ITO thin film as top electrodes are made by a magnetron sputtering method. The threshold voltage, emittin spectrum, the relationship of brightness and voltage of this device are mesured. The emitting mechism and the relationship of efficiency and voltage also are studied. The relationship of threshold voltage and insulator is analysed.Through these analysis, we optimized the the manufacturing method in many ways such as thick-film's fabriacating condition and the thickness of thick-film. Then the TDEL device have been developed with following characteristics:1. It can emit light at low ac voltage. The threshold voltages is 60V.2. It is free from breakdown failures. Thus it is more reliable and stable.3. Emitting light brightness and color do not depend on viewing angles.4. It has high contrast.Highly reliable and legible EL display panels will be fabricated using TDEL composite structure devices.