| 摘要 |
PURPOSE:To improve wetting characteristic of solder on a lead and enhance reliability of loading by providing a groove or recess and protrusion for absorbing solder at the surface to be connected to external circuit of the lead protruded externally or the surface adjacent thereto. CONSTITUTION:In the case of a flat package type semiconductor device, a plurality of fine grooves 8 are engraved in parallel on the lower surface of lead end to be connected to a wiring layer which is an external circuit of outer lead 2 protruded and bent at the outside of side surface of package 1 or on the surface adjacent thereto. Thereby, on the occasion of loading a semiconductor device on a wiring substrate by soldering, the solder 5 can be fused uniformly at the area where the lead 2 and a wiring layer 4 are connected at the rising part 6 and the fine groove can absorb a sufficient amount of solder 9 along the upright part of lead by the capillary action. Accordingly, strength against the exfoliation of lead can be strengthened and more solder can be applied to the soldering surface. |
