| 摘要 |
PURPOSE:To increase a lead-frame tightening pressure per unit area in a metal mold for resin sealing of a semiconductor device to prevent leakage of resin by a method wherein relief recesses are built in a mold registering surface so that a contact plane with a fixed width is reserved in edges around cavities, runners and culls on at least one of an uper metal mold and a lower metal mold. CONSTITUTION:Recesses 9 about 0.5mm. deep are built around an edge 8 of a cavity 4 of an upper, for example, metal mold 1 of a metal mold for use in transfer molding leaving the part of about 1mm. width contacting a lead frame 3. Further, for a cull part 6 and a runner 7 of a center block 5 also, a frame 8 of 0.1-3mm. width and a relief recess 9 of about 0.5mm. depth are built. With this structure, even when there are some dispersions among the thickness of the lead frames and/or burr protrusions, gaps creating leakage of resin between lead frames and molds can be eliminated because the tightening pressure per unit area of the lead frame 3 increases and also burrs are accommodated in recesses 9. |
