| 摘要 |
PROBLEM TO BE SOLVED: To reduce the manufacturing cost of a mold for a package and to make the manufacture of the mold easier by fixing a solderable metallic body to the rear surface of a package so as to prevent the excessive crushing of solder balls. SOLUTION: Solder-plated spheric Cu core balls 5 are soldered onto pads 6 provided at the corner sections 2a of the rear surface 2 of a package 1. The diameters of the core balls 5 are made smaller than those of solder ball electrodes 3 by about 100-150μm by taking the height reduction of the solder balls 3 when the package 1 is mounted on a substrate in to account. When the plated solder thicknesses on the surfaces of the core balls 5 are made about 50μm on one side, the diameters of the balls 5 before the package 1 is mounted on the substrate become nearly equal to those of the solder balls 3 and, even after the package 1 is mounted, the diameters of the balls 5 can be made nearly equal to those of the solder balls 3. When the core balls 5 are used, the sealing mold of the package 1 can be manufactured in a simple constitution, because it becomes unnecessary to provide hols for projection in the mold, and at the same time, the core balls 5 can also be attached in the same process as that for the solder ball electrodes 3.
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