A driver integrated circuit chip adapted to electrically couple with a fan-out wiring area includes a side and a plurality of output pins formed at the side. The output pins includes a first pin group and a second pin group. The first pin group is electrically coupled to the fan-out wiring area. The second pin group is located at at least one side of the first pin group and opened. The present invention also provides display substrates of flat panel display each adapted to electrically couple with a plurality of driver integrated circuit chips.