The Preparation of Phosphor Screen for Video Phone Tube by Screen Printing Method

The phosphor and ITO(Indium Tin Oxide) films for video phone tube (VPT) were simply prepared by the screen printing and thermal transfer methods. The increasing order of thermal firing of acrylic binder for phosphor and ITO was M6003 < M6664 < A/A 1919 < M500l < M670 1 and all mass of binders were perfectly decomposed at lower temperature than $400^{\circ}C.$ After thermal firing of phosphor paste, the residual of binder on the surface of phosphor could not be found by SEM. Aerosil as thickner provides the thixotropy property for phosphor paste but decrease the brightness of phosphor screen as residual after thermal firing. Since the thixotropy of M5001 binder without aerosil was shown and the storage modulus of phosphor paste by increasing the angular frequency was not nearly changed and the decrease of the storage modulus of phosphor paste by increasing the strain was remarkably shown. It was possible to prepare the phosphor paste which was predominant in the plate separation and the reproduction of pattern after the screen printing. Since the addition of dispersing agent to improve the printing process decreases the electrical conductivity and light transmission of ITa film, it could be found to be necessary the development of binder for phosphor paste that decreases the amount of dispersing agent possibly and does not use the aerosil as additive.

Screen Printing법에 의한 Video Phone Tube용 형광막 제조