| 摘要 |
PROBLEM TO BE SOLVED: To improve the joining strength of the soldering ball and land of BGA. SOLUTION: In T-TFBGA IC 34 wherein a semiconductor pellet 10 is mechanically and electrically connected to a plurality of inner leads 24 laid on a carrier tape body 21 and the soldering balls 33 are soldered on each land 28 formed on an outer lead 25 connected to each inner lead 24, a joining strength improvement groove 29 is recessed on the main face of the connection side of the soldering ball 33 of the land 29, and the soldering ball 33 is anchored to the joining strength improving groove 29. Since the soldering ball is anchored to the joining strength improvement groove, joining strength between the soldering ball and the land is sufficient even when the area of the plane of the land is small, and an accident in which the soldering ball is peeled from the land can be prevented surely.
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