Display apparatus and electronic apparatus including the same

A display apparatus comprising:

• a substrate comprising defined therein:
• a main through hole extended through a thickness of the substrate,
• a first groove extended around the main through hole to be disposed outside the main through hole, and
• a first test concave portion disposed outside the main through hole;
• and
• an insulating layer on the substrate, the insulating layer comprising defined therein:
• a main insulating through hole aligned with and connected to the main through hole of the substrate along the thickness thereof,
• a first insulating through ring extended around the main insulating through hole to be disposed outside the main insulating through hole, the first insulating through ring connected to the first groove of the substrate along the thickness thereof, and
• a first insulating through hole disposed outside the main insulating through hole, the first insulating through hole connected to the first test concave portion of the substrate along the thickness thereof,
• wherein along a same width direction:
• a width of the first insulating through ring of the insulating layer is less than a width of the first groove of the substrate, and
• a width of the first insulating through hole is less than a width of the first test concave portion.