| 摘要 |
PURPOSE:To prevent the generation of voids and a molding failure, such as the deformation of wires or the like, by a method wherein as resin injection holes, which select gates and are connected to the gates, are provided at two places or more in each cavity so that the flow of a sealing resin to be injected in each cavity flows in a forward direction, the gates of a metal mold can be arranged symmetrically to a runner and the flow of the sealing resin from the runner is made to flow in the forward direction. CONSTITUTION:A molding resin which is the material for a package 1 is flowed in the package 1 from the direction shown by an arrow to a runner 3, is brached by gates 4a to 4d provided at respective cavities 5 and is injected in the cavities 5 through resin injection holes 6. In the case that the gates 4a to 4d are arranged, a metal mold 2 can be arbitrarily selected by the arrangement of a lead frame 7. In this embodiment, the gates 4a to 4d can be arranged symmetrically to the runner 3 and the flow of the sealing resin from the runner 3 is made to flow in a forward direction. The holes 6 are arranged at two places of the corner parts of each cavity, but even if the holes 6 are arranged at the corner parts more than two places to select the gates, the same effect as that in the case of the arrangement at two places of the corner parts is obtained. A selection of the metal mold 2 from a case A and a case B can be easily performed by forming the parts of the gates 4a to 4d into an insert type. |
