| 摘要 |
PURPOSE:To perform a highly reliable resin sealing by a method wherein resin tablets are placed in the pot part of a sealing mold in such a manner that those tablets having a shorter spiral flow (the flowing state of resin material) are positioned on the lower side and those tablets having a longer spiral flow are positioned on the upper side, and heat and pressure are applied to them. CONSTITUTION:A lead frame is pinched between the upper and the lower molding molds 9 and 18, a plurality of resin tablets having different flowing states are placed in pots 10 and 19 as prescribed, a plunger is inserted into a hole 19, and heat 7 and 16 and pressure are applied to them. As the resin material on the lower side has a shorter spiral flow, it does not flow as far as to a runner 11b which is located apart, it flows mainly to the runners 11a and 11b, the resin material on the upper side flows to a runner 11c located apart, and it is accurately injected to the cavity which is interconnected to the runner 11b. As a result, the generation of voids can be prevented completely and the disconnection of thin metal wires can also be prevented, because it is unnecessary to increase the injection pressure above that which is required. The cross-sectional area of the runners 11a-11c is selected as phi0>phi1>phi2 respectively. |
