BUMP FORMATION METHOD AND WIRING BOARD WITH BUMP

PROBLEM TO BE SOLVED: To provide a method for forming columnar bumps on a wiring board by plating, which allows for formation of small diameter bumps with high yield that is difficult by a conventional method.SOLUTION: A method for forming bumps includes a hydrophilic step for hydrophilizing the resist on the inner wall of a resist aperture in a resist patterned substrate, an etching step for immersing the resist aperture in the resist patterned substrate into etchant, and etching the electrode pad surface over a range wider than the aperture, a plating step for forming a bump in the aperture of the resist patterned substrate by plating, and a resist removal step for removing the resist pattern.