PROCESS FOR FORMING BUMP

PROBLEM TO BE SOLVED: To provide a process for forming bumps on a substrate in which the occurrence of bump defects is suppressed without requiring a high precision device or jig for applying flux. SOLUTION: In the process for forming bumps by heating a substrate mounting conductive balls on a UBM coated with flux to fuse the conductive balls and then cooling and solidifying the fused conductive balls, heating is carried out in at least three temperature regions of a temperature for evaporating and removing at least a part of solvent contained in the flux, a preheating temperature for removing the UBM and an oxide film on the surface of the conductive balls, and a reflow temperature for fusing the conductive balls to metal bond the UBM and the conductive balls. COPYRIGHT: (C)2005,JPO&NCIPI