Organic light emitting diode display panel for improving light transmittance and organic light emitting diode display device

An organic light emitting diode display panel, comprising:

• a first display region comprising a first substrate layer, a thin film transistor layer disposed on the first substrate layer, and a first pixel layer disposed on the thin film transistor layer;
• and
• a second display region disposed adjacent to the first display region, wherein the second display region comprises a second substrate layer and a second pixel layer disposed on the second substrate layer;
• wherein the first pixel layer comprises a first anode and a first cathode, the second pixel layer comprises a second anode and a second cathode, wherein a bottom surface of the first anode is coplanar with a bottom surface of the second cathode, the thin film transistor layer comprises a thin film transistor, and the first anode and the second anode are electrically connected to the thin film transistor disposed on the first substrate layer of the first display region, the thin film transistor layer is not disposed in the second display region, a pixel unit in the first pixel layer and a pixel unit in the second pixel layer respectively correspond to the thin film transistor disposed on the first substrate layer of the first display region for the thin film transistor disposed in the first display region to control the display function of the second display region;
• wherein a second buffer layer is disposed between the first substrate layer and the thin film transistor layer, and a first planarization layer is disposed between the thin film transistor layer and the first pixel layer;
• wherein a second planarization layer is disposed between the second substrate layer and the second pixel layer;
• wherein the thin film transistor layer further comprises:
• an active layer, a first insulating layer disposed on the active layer, a first metal layer disposed on the first insulating layer, a second insulating layer disposed on the first metal layer, a second metal layer disposed on the second insulating layer, a third insulating layer disposed on the second metal layer, and an electrode layer disposed on the third insulating layer;
• a first through hole is disposed penetrating through the first insulating layer, the second insulating layer, and the third insulating layer, and wherein the electrode layer is electrically connected to the active layer through the first through hole;
• a second through hole is disposed penetrating through the first planarization layer, and the first anode is electrically connected to the electrode layer through the second through hole;
• wherein a metal trace is disposed between a second flexible layer of the second substrate layer and the second planarization layer, the metal trace is disposed at a junction between the second planarization layer and the thin film transistor layer, the metal trace is electrically connected to the electrode layer and the metal trace is electrically connected to a drain of the thin film transistor;
• wherein a third through hole is disposed penetrating through the second planarization layer, and the second anode is electrically connected to the metal trace through the third through hole;
• and
• wherein a bonding interface of the first display region and the second display region is stepped, and the metal trace is electrically connected to the electrode layer along the stepped bonding interface.