AVS 46th International Symposium
    Flat Panel Displays Topical Conference Tuesday Sessions
       Session FP-TuM

Paper FP-TuM7
Transparent and Conductive Ultra-barrier Coatings for Flexible Plastic Displays

Tuesday, October 26, 1999, 10:20 am, Room 604

Session: Novel Materials for Field Emission Displays and Technologies for Flexible Displays
Presenter: C.I. Bright, Delta V Technologies
Correspondent: Click to Email
One of the major issues limiting fabrication and lifetime of flexible displays is the moisture and oxygen permeability of the polymeric substrates. The acceptable value of permeation depends on the sensitivity of the particular display technology. Another flexible displays issue is the low temperature capability of optical quality plastic substrates. This restriction on process temperatures has many implications in display fabrication. One example is the low conductivity of the Transparent Conductive Oxide (TCO) used for the necessary transparent electrode layer. An organic layer deposited by the Polymer MultiLayer (PML) process for vacuum evaporation of organic monomers and in-situ e-beam or UV polymerization has demonstrated excellent smoothing of substrate surfaces. When dielectric layers of Al@sub 2@O@sub 3@ or SiO@sub 2@ are combined with PML deposited organic polymer layers; outstanding barrier properties are achieved on flexible plastic film substrates. A PML base coat layer also should provide a clean smooth surface for bonding and nucleation of a deposited TCO. In this work, we combined a PML base coat and a TCO layer to form a transparent conductive barrier where the TCO functions as both the moisture and oxygen barrier, and the required transparent electrode for the display. Multiple pairs of polymer/TCO layers can be used to increase both barrier performance and conductivity, as needed, for a particular display technology. The experimental results for ITO sputtered directly onto a PET substrate, and with a PML acrylic base coat, in a roll-to-roll (web) coating process are reported. The optical, electrical and barrier properties for both constructions were measured and compared. Very preliminary barrier results show permeation values of 0.05 - 0.005 O@sub 2@ cc/m@super 2@/day, H@sub 2@O g/m@super 2@/day, for single layer ITO on a PET (0.007" thick) substrate.