Active liquid crystal display panel having a short-circuit metal layer and welding metal pads for changing the defect of a defective pixel

Claim 1

An active liquid crystal display panel wherein a plurality of source lines and a plurality of gate lines are provided across each other over the inside surface of a first transparent substrate facing a second transparent substrate with liquid crystal sealed in the space defined therebetween, said second transparent substrate is deposited substantially all over its inside surface with a common electrode, pixel electrodes are each provided in one of areas defined by said intersecting source and gate lines to form a pixel, thin film transistors are each provided near one of said pixel electrodes, and said each thin film transistor has its source and gate connected to said source and gate lines corresponding thereto, respectively, said pixel comprising: a first transparent insulating layer formed between said pixel electrodes and said first transparent substrate; a second transparent insulating layer formed on the inside surface of said first transparent substrate, covering said first transparent insulating layer and said pixel electrode; a short-circuit metal layer formed between said first substrate and said first insulating layer, one end portion of said short-circuit metal layer underlying a marginal portion of said each pixel electrode corresponding to said one thin film transistor in a first welding region but separated therefrom by at least said first insulating layer and the other end portion of said short-circuit metal layer underlying a part of at least one of said source and gate lines adjacent said each pixel electrode but separated therefrom by at least said first insulating layer in a second welding region; first and second welding metal pads formed between said first and second insulating layers overlapping said short-circuit metal layer in said first and second welding regions but separated therefrom by at least said insulating layer; and third and fourth welding metal pads formed of a ductile metal on said second insulating layer right above said first and second welding metal pads in said first and second welding regions.