Organic light emitting diode display device

An organic light emitting diode (OLED) display, comprising

• a substrate;
• an overlapping layer on the substrate;
• a buffer layer on the layer;
• a semiconductor layer on the buffer layer;
• a first gate insulation layer that covers the semiconductor layer;
• a first gate layer on the first gate insulation layer;
• a second gate insulation layer that covers the first gate layer and the first gate insulation layer;
• a second gate layer on the second gate insulation layer;
• an interlayer insulation layer that covers the second gate layer and the second gate insulation layer;
• a data layer on the second gate insulation layer;
• a passivation layer that covers the data layer and the interlayer insulation layer;
• a transistor that includes a channel formed in the semiconductor layer and a gate electrode formed in the first gate layer;
• and
• an organic light emitting diode electrically connected to the transistor, wherein
• the overlapping layer overlaps the channel of the transistor on a plane,
• a contact hole is formed in at least a part of the buffer layer, the first gate insulation layer, the second gate insulation layer, or the interlayer insulation layer,
• a pixel includes the organic light emitting diode and at least one transistor electrically connected to the organic light emitting diode,
• a pixel area is an area that the at least one transistor included in the pixel is disposed on a plane, and
• the overlapping layer is exposed by the contact hole which is disposed in the pixel area.