The end surface 82E of the first connection layer 82 may be exposed to the outside, like the end surface 80E of the first thermally conductive layer 80. Accordingly, the end surface 82E of the first connection layer 82 and the end surface 80E of the first thermally conductive layer 80 may be aligned with each other and may be on the same plane.

When the first connection layer 82 extends to the edge 100E of the lower substrate 100, like the first thermally conductive layer 80, and is exposed to the outside of a panel, higher heat dissipation efficiency may be achieved.

When the end surfaces 82E and 80E of the first connection layer 82 and the first thermally conductive layer 80 are exposed to the outside of the panel, in the end surfaces 82E and 80E could be susceptible to oxidation. Accordingly, a metal material included in each of the first connection layer 82 and the first thermally conductive layer 80 may include a metal that is less reactive than a metal material included in the common power supply line 70. For example, when the common power supply line 70 includes aluminum (Al), each of the first connection layer 82 and the first thermally conductive layer 80 may include molybdenum (Mo), which is less reactive than Al.

The configuration may apply even when only the end surface 80E of the first thermally conductive layer 80 is exposed to the outside of the panel.