Improvement of alkali durability of silver-based multilayer coatings for use in flat panel displays

Silver-based multilayer coatings are well known to be transparent films wit h low electrical resistivity. In particular, indium and zinc composite oxid e (IZO)/silver containing palladium (AgPd) multilayer coatings have good pa ttering properties and durability. However, the IZO/AgPd multilayer coating s do not have sufficient alkali durability as transparent electrodes of fla t panel displays (FPDs). In order to solve this problem, coatings covered w ith a protective layer of tin-doped indium oxide (ITO) were investigated. O ver-coating of an ITO layer degraded the patterning properties of the multi layer coatings because the etching rates of ITO, IZO and AgPd layer were ve ry different. From the viewpoint of controlling the etching rate of each la ver independently, the etching solution composed of hydrobromic acid and ir on chloride was adjusted, so that the ITO/IZO/AgPd/IZO/AgPd/IZO/substrate m ultilayer coatings could be fabricated into fine patterns for electrodes. T he multilayer coatings thus prepared are more tolerable for alkali detergen ts used in the production process of FPDs.