OLED display panel and OLED device with wire overlying step in via-holes, and manufacturing method thereof

A method for manufacturing an OLED display panel, comprising:

• forming a first film layer on a base substrate, and forming a first via-hole penetrating through the first film layer;
• forming a second film layer on the first film layer, and forming a second via-hole penetrating through the second film layer at a position of the second film layer corresponding to the first via-hole, the second via-hole being in communication with the first via-hole, the second film layer and the first film layer forming a first step at a position of the second via-hole;
• and
• forming a connection wire at a position corresponding to the second via-hole and the first via-hole, the connection wire being in both the first via-hole and the second via-hole and overlying the first step,
• wherein forming the first film layer on the base substrate, and forming the first via-hole penetrating through the first film layer comprises:
• forming an insulation layer on the base substrate, and forming the first via-hole penetrating through the insulation layer;
• wherein forming the second film layer on the first film layer, and forming the second via-hole penetrating through the second film layer at a position of the second film layer corresponding to the first via-hole comprises:
• forming a planarization layer on the insulation layer, and forming the second via-hole penetrating through the planarization layer at a position of the planarization layer corresponding to the first via-hole, the second film layer and the first film layer forming the first step at a position of the second via-hole;
• wherein the method further comprises:
• forming a source-drain electrode layer between the insulation layer and the planarization layer, the source-drain electrode layer overlays the first via-hole, the planarization layer and the source-drain electrode layer form the first step at a position of the second via-hole.