| 摘要 |
PURPOSE:To enable gas within a mold cavity to be removed completely for preventing short molding or voids in resin packages due to residual gas, by dividing resin injected from the gate into the cavity into two separate flows flowing over and below a frame and controlling these flows such that they join together at the position of an air vent provided on the side of the mold opposite to the gate. CONSTITUTION:When molten resin is injected from a gate 9 into the cavity of a transfer molding mold 8, the molten resin is divided into two separate flows A and B flowing over and below a frame 2, respectively. By adjusting a height of a projection 12 provided on the mold 8 appropriately, the flow of resin, particularly the flow over the frame 2 can be restricted and controlled by the projection 12 appropriately such that the two flows A and B join together just at a position a of an air vent 11 opening at the terminal side of the mold 8. Accordingly, all the gas within the cavity can be removed through the air vent 11 without any residual air entrapped.
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