| 摘要 |
PURPOSE:To acquire a lead frame wherein cutting of a tie bar by a punching device is not required after resin sealing process by making each tie bar extruded from a surface of a lead by a specified amount in a thickness direction of the lead frame. CONSTITUTION:A tie bar 41 is extruded from a surface of a lead 42 in a thickness direction of a lead frame 40. As for an extrusion amount (b) of the tie bar 41 from a surface of the lead 42, just an amount is required, which is enough to allow the tie bar 41 and the lead 42 to separate because a boundary between the tie bar 41 and the lead 42 is ruptured when the tie bar 41 is forced back. Therefore, the extrusion amount (b) should be just 1/2 or more of a thickness (a) of the lead frame 40. However, from a view point of readiness of extrusion and forcing back, etc., about 1/2 is desirable as for a ratio b/a. Thereby, a boundary between a tie bar and a lead is ruptured and they are separated when a lead frame is clamped with a die in a resin sealing process. |
