Display device with connection board and method of testing pad contact state thereof

A display device, comprising:

• a display panel comprising a plurality of panel pads;
• a plurality of connection boards, each of which comprises first to fourth connection board pads and a connection board output pad;
• and
• a main circuit board comprising a plurality of output receiving pads coupled to the connection board output pads of the plurality of connection boards,
• wherein the plurality of panel pads comprises first and second panel pads electrically connected to each other, and third and fourth panel pads electrically connected to each other,
• the first to fourth connection board pads of one of the plurality of connection boards are coupled to the first to fourth panel pads, respectively,
• each of the plurality of connection boards comprises a driving circuit, and
• the driving circuit of the one of the plurality of connection boards is electrically connected to the first to fourth connection board pads, generates a first test result signal based on a first panel test signal transmitted to the first connection board pad, a first panel feedback signal received from the second connection board pad, a second panel test signal transmitted to the third connection board pad, and a second panel feedback signal received from the fourth connection board pad, and outputs the first test result signal to the connection board output pad.

A method of testing a pad contact state of a display device comprising a display panel and a connection board, the display panel comprising a first panel pad and a second panel pad electrically connected to each other, and a third panel pad and a fourth panel pad electrically connected to each other, and the connection board comprising first to fourth connection board pads, the method comprising:

• coupling the first to fourth connection board pads to the first to fourth panel pads, respectively;
• transmitting a first panel test signal to the first connection board pad and transmitting a second panel test signal to the third connection board pad;
• receiving a first panel feedback signal from the second connection board pad and receiving a second panel feedback signal from the fourth connection board pad;
• generating a first test result signal based on a first difference between the first panel test signal and the first panel feedback signal;
• generating a second test result signal based on a second difference between the second panel test signal and the second panel feedback signal;
• and
• sequentially outputting the first test result signal and the second test result signal.