Signal line structure of a flat display

A signal line structure disposed between a gate driver and a display area of a display, comprising:

• a substrate;
• a plurality of first metal layer, wherein the first metal layers are arranged in parallel and toward a first direction in the substrate;
• a first insulation layer, wherein the first insulation layer is disposed in the substrate and covers the first metal layers;
• a plurality of second metal layer, wherein the second metal layers are disposed on positions corresponding to the first metal layers in the first insulation layer;
• a second insulation layer, wherein the second insulation layer is disposed on the second metal layers and the first insulation layer;
• and
• a plurality of third metal layer, wherein the third metal layers are disposed on the positions corresponding to the second metal layers in the second insulation layer,
• wherein the distance between two adjacent second metal layers is less than the distance between two adjacent first metal layers.