| 摘要 |
PURPOSE:To manufacture the lead frame which scarcely generates a lead shift and has no flaw in the internal lead by forming in advance a groove in the part in which punching is executed, and negating the lead shift at the time of forming the internal lead. CONSTITUTION:To the root part of an internal lead 14 of the part which becomes a slug, a groove, desirably, a groove 16 whose cross section is a V- shape is formed before punching. A stock in the vicinity of the groove is spread out to the outside around the groove, and to the part which becomes an internal lead, a strain turned in the direction as indicated with an arrow A is given in advance. In the case punching is executed without forming the groove, the internal lead moves in the direction as indicated with an arrow B. Accordingly, by giving in advance a strain in the direction reverse to the moving direction at the time of punching to the internal lead, the motion of the internal lead at the time of punching is negated, and a lead shift is relaxed. |
