| 摘要 |
PROBLEM TO BE SOLVED: To improve the life of a second solder connecting a lead terminal and a second land on a circuit board provided with a semiconductor device of a QFN structure.SOLUTION: A circuit board (10) is provided with a semiconductor device (11) of a QFN structure and a printed circuit board (12), the underside (20b) of an island part (20) protruding downward more than does the underside (22b) of a lead terminal part (22). A side surface (20c) of the island part has an exposed part (20c1) which is in a range from the underside and is exposed from a sealing resin body (23) and a covering part (20c2) which is a portion above the exposed part and is covered with the sealing resin body. A first land (31) has an overlap part (31) overlapping the island part and an extension part (31b) extended from the overlap part and overlapping an underside (23b) of the sealing resin body. A first solder (13) includes a first fillet part (13a) connecting the extension part of the first land and the exposed part of the island part. |
