Array substrate and its manufacturing method and display panel

An array substrate comprising a substrate, a TFT functional layer, a touch signal transmission line, a first insulating layer, a first electrode, a second insulating layer, a second electrode, and a metal pattern, wherein the substrate, the TFT functional layer, the touch signal transmission line, the first insulating layer, the first electrode and the second insulating layer are sequentially stacked, the second electrode and the metal pattern are stacked on the second insulating layer;

• wherein the first electrode serves both as a common electrode and also as a touch sensor;
• wherein the second insulating layer is arranged with a first via and a second via formed by photolithography, the first via comprises a first through hole extending through the second insulating layer and a second through hole, the second through hole comprises a first sub-through hole extending through the first electrode and a second sub-through hole extending through the first insulating layer, a width of the first sub-through hole is equal to a width of the second sub-through hole, a width of the first through hole is larger than the width of the first sub-through hole and the width of the second sub-through hole so that the bottom of the first through hole exposes a portion of the upper surface of the first electrode, the bottom of the second through hole exposes a portion of the upper surface of the touch signal transmission line, the second via making the source and/or drain in the TFT functional layer exposed;
• wherein the second electrode and the metal pattern are fabricated using the same metal layer, the metal pattern connects the touch signal transmission line and the first electrode through the first via, the second electrode connecting the source and/or drain through the second via.