| 摘要 |
<p>PURPOSE:To improve soldering strength by forming a step part on the surface of an outer lead on the side which is soldered with a board, and making the tip of the outer lead a thin-wall part. CONSTITUTION:An outer lead 1 has metal material 4 having conductivity and a solder-plating part 3 formed thereon, and a thin-wall part 1b is formed at the tip part. This thin-wall part 1b has a step part on the surface of the lead 1 on the side to be fixed with a mounting board surface. Said step part is thinned and a solder-plating part 3 is formed. A semiconductor chip is mounted on the mounting surface of a lead frame, and sealed by using resin material. The lead frame stretching outward is solder-plated from the resin material. At this time, solder is stuck in a sufficient thickness on the lower surface side of the thin-wall part 1b by the effect of the surface step, thereby obtaining sufficient soldering strength of the lead 1.</p> |
