An organic light emitting diode (OLED) display device and a manufacturing
method thereof to improve a luminous character are provided. The OLED
display device includes a first transistor, a second transistor and an
OLED. An image is displayed by applying a driving current to OLED through
the first transistor and the second transistor. The thickness of the gate
insulating layers of the first and the second transistor are different.
The OLED is provided with the sufficient driving current to improve the
luminous character without decreasing emissive area.