A substrate includes a first input/output region; a first input pad provided in the first input/output region; a first output pad provided in the first input/output region; a first mounting region; a first positive pad provided in the first mounting region and connected to the first input pad; a first negative pad provided in the first mounting region connected to the first output pad; a second positive pad provided in the first mounting region; a second negative pad provided in the first mounting region; a second mounting region; a third positive pad provided in the second mounting region and connected to the second positive pad; a third negative pad provided in the second mounting region and connected to the second negative pad; a fourth positive pad provided in the second mounting region; a fourth negative pad provided in the second mounting region; a second input/output region; a second input pad provided in the second input/output region and connected to the fourth positive pad; and a second output pad provided in the second input/output region and connected to the fourth negative pad.