Display device and manufacturing method thereof that may minimize an occurrence of a defect in the display device

A display device comprising:

• a substrate divided into an encapsulation area and a non-encapsulation area;
• an interlayer insulating layer disposed over the substrate;
• an inner conductive layer disposed on the interlayer insulating layer in the encapsulation area;
• an outer conductive layer disposed on the interlayer insulating layer in the non-encapsulation area;
• an inner lower conductive layer disposed below the interlayer insulating layer in the encapsulation area;
• an outer lower conductive layer disposed below the interlayer insulating layer in the non-encapsulation area;
• and
• a first inner contact hole passing through the interlayer insulating layer and connecting the inner conductive layer to the inner lower conductive layer;
• and
• an outer contact hole passing through the interlayer insulating layer and connecting the outer conductive layer to the outer lower conductive layer,
• wherein a slope angle formed by a lateral wall of the outer contact hole with respect to an upper surface of the substrate is less than a slope angle formed by a lateral wall of the first inner contact hole with respect to the upper surface of the substrate.