| 摘要 |
PURPOSE:To prevent the generation of resin bur particularly at lead parts by forming the structure of the surface pressure part of a resin sealing metal mold into uneven form so that load is applied only on the leads. CONSTITUTION:The surface pressure part 18 has projections 181 and recesses 182 composed by alternate repetition. In a cross-section C of a resin sealed lead frame, the numeral 31 represents a lead frame, 32 a resin part, 33 leads, and regions 34 shown by oblique lines 34 regions pressed by the projections 181. By positioning the projections 181 with respect to each lead 33 in such a manner, the generation of bur from the oblique line part 34 is blocked by applying a pressure larger than conventional at the center of the lead 33. Further, in the Fig. A, the projections 181 of the resin sealing metal mold 15 of the upper mold are positioned on the leads 33, and thus the pressing on the leads 33 is increased. In the Fig. B, the projections 181 are positioned onto the midpoint in the longitudinal direction of the lead 33, and then the pressing at the center of the lead 33 is further increased. |
