| 摘要 |
PURPOSE:To prevent the connection of fractured sections of a resin of the same thickness as that of a frame material between leads after the unnecessary resin is punched, by a method wherein the part of side surface between IC leads at the high-bar section of a metal mold is provided with a projection. CONSTITUTION:The dam 3a surrounded by leads 1 and a tight-bar 2 is provided with a projection 6 of rectangular piece form. Sealing by pressing a resin 5 fit in this metal mold generates an unnecessary bur of resin 31. When this unnecessary bur of resin 31 and the projection 6 are removed by being punched out, fractured sections 8 formed between the inside-surface leads of a resin- sealed IC come not to be joined between the leads 1. Therefore, Ag migration does not generate in the Ag-plated leads 1, resulting in resin sealing of high reliability. It is practically advantageous to provide the piece projection 6 in a form of rectangular prism to the degree of no connection of fractured sections 8 between the leads. |
