BUMP FORMING APPARATUS AND BUMP FORMING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a bump forming apparatus and a bump forming method wherein a bump that does not protrude from a pad and has a high bond strength can be formed. SOLUTION: A substantial part of this bump forming apparatus is a lower end opening part of a capillary, and comprises a wire hole 42 for making a wire which is a material forming the bump penetrate through in a longitudinal direction of the capillary, a two-step step-like recess 44 formed at a lower end of the capillary, and an opening 46 of the wire hole equipped at the deepest part of the two-step step-like recess. The two-step step-like recess is constituted of a cylindrical large diameter recess 48 and a cylindrical small diameter recess 52 continuously formed from a bottom face 50 of the large diameter recess 48 in a concentric circle in its back portion. The opening 46 of the wire hole is equipped in a center of a bottom face 54 of the small diameter recess. One part of a ball formed at a wire tip is stored in the small diameter recess 52, and thus the size, mainly the height of the bump becomes large. Almost all the ball formed at the wire tip, aside from one part stored in the small diameter recess 52, is stored in the large diameter recess 48, and thus the size of the bump, in particular, the diameter of the bump is prevented from becoming too large.