An active array matrix substrate of a display panel includes a number of scan lines parallel to each other and arranged in a first metal layer of a first substrate, a number of data lines parallel to each other and arranged in a second metal layer of the first substrate, a number of gate electrodes arranged in the first metal layer, a number of source electrodes arranged in the second metal layer, and a number of drain electrodes arranged in the second metal layer. The source electrode includes at least one source extending portion spaced from and configured to overlap with the first metal layer. The drain electrode includes at least one drain extending portion spaced from and configured to overlap with the first metal layer.