Pixel unit, fabrication method thereof, array substrate, and display device

A method for fabricating a pixel unit, comprising:

• providing a substrate;
• forming a thin film transistor including a drain electrode over the substrate;
• forming a first insulating layer over the drain electrode;
• forming a via hole in the first insulating layer, an orthogonal projection of the via hole on the substrate at least partially overlapping with an orthogonal projection of the drain electrode on the substrate, the via hole penetrating through the first insulating layer along a thickness direction of the first insulating layer and exposing a portion of a surface of the drain electrode;
• forming a pixel electrode over the first insulating layer, a portion of the pixel electrode being in the via hole and electrically coupled to the drain electrode;
• forming a second insulating layer over the pixel electrode and covering the pixel electrode, a portion of the second insulating layer being over the via hole;
• forming a meltable conductive component over the second insulating layer, a portion of the meltable conductive component being over the via hole, and the meltable conductive component and the pixel electrode being insulated from each other by the second insulating layer;
• and
• forming a common electrode over the meltable conductive component and electrically coupled to the meltable conductive component.