A method of forming a bump on a substrate such as a semiconductor wafer or flip chip without producing metal ribbon residue. In one embodiment, a voltage-level converter connects a first logic unit connected to a first supply voltage to a second logic unit connected to a second supply voltage. When performing multi-chip test, the connection result is displayed after checking the test mark signal by the discrimination circuit. Upon sliding a switch member upward, a setting segment thereof pushes up an abutting pin integrally formed with the stop plate so that the stop plate is rotated to move toward the outside of the lens-holding rib through the cut portion.