| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a bump, which can stand a thermal shock and an accidental external force, which is applied during conveyance of the bump, and corresponds to a narrow-pitch application, without through a complicated process. SOLUTION: A mushroom-shaped solder plating is formed on a metal core 4 and then, it is conducted that the mushroom-shaped solder plating is molten and is formed into a spherical form. In this case, the core 4 is formed into a column or a regular polygonal prism, the distance from the radius of the column or the central axis of the regular polygonal prism to the vertical angle is assumed (b) and the height under the umbrella and umbrella part height of the mushroom-shaped solder plating are respectively assumed h1 and (r) to form the core 4 and the mushroom-shaped solder plating while the lengths of the core 4 and the solder plating are measured so as to satisfy the relation of 4r<3> +3πbr<2> +6b<2> r+6h1b<2> -4b<3> <=0.</p> |
