Layered wiring line of silver or silver alloy and method for forming the same and display panel substrate using the same

摘要

A layered wiring line of silver or silver alloy includes a silver or silver alloy conductor layer (32) including silver or silver alloy; and a protective conductor layer (31) layered on and covering the silver or silver alloy conductor layer. A method for forming the layered wiring line includes steps of: layering the silver or silver alloy conductor layer and the protective conductor layer on a substrate in turn; making the protective conductor layer in contact with a liquid etchant common to the silver or silver alloy conductor layer and the protective conductor layer by a predetermined pattern. The protective conductor layer has a thickness satisfying a relationship in that a ratio of (the protective conductor layer's thickness) / (the silver or silver alloy conductor layer's thickness) is less than that of (a solution velocity of the protective conductor layer in the liquid etchant) / (a solution velocity of the silver or silver alloy conductor layer in the liquid etchant).