1. A manufacturing method of a display device, the manufacturing method comprising:disposing a base substrate on a supporting substrate having a top surface;
forming a display region and a terminal over a second top surface of the base substrate, the second top surface of the base substrate overlapping the top surface, so that the terminal is sandwiched between the display region and a side surface of the base substrate;
dividing the supporting substrate and then removing a part of the base substrate in a region between the side surface and the terminal so as to form a trench at the second top surface of the base and to expose the supporting substrate;
connecting a connector to the terminal using an anisotropic conductive film after forming the trench; and
separating the supporting substrate from the base substrate after connecting the connector.