Abstract: This invention relates to a lead frame which is applied to a resin-molded semiconductor device. According to the lead frame of this invention, a quadrangular tab for supporting a semiconductor pellet is supported by four tab leads which extend along diagonal lines of the tab.

Abstract: A mold die including two or more cavities shaped to profile the configuration of mold products, a pot serving as a lead-in portion for resin of a tablet-form, or a sprue serving as a lead-in portion for molten resin, a runner leading to the pot or sprue, and gates branching from the runner and leading to respective cavities, the aforesaid gates having given convergent slopes at their exits to the cavities. The cross-sectional area of the runner is progressively decreased in the direction away from the pot or sprue, and the convergent slopes of the gates are progressively increased in the direction away from the pot or sprue, in a manner that the sum of a pressure drop in a runner portion and a pressure drop in a gate portion may be made equal for each of the cavities, thereby minimizing a difference in timing of resin to arrive respective cavities, and rendering the velocity of resin flowing into respective cavities equal to one another.

Abstract: A single in-line, high power, resin-packaged semiconductor device having a plurality of external leads disposed in parallel to each other and projecting from one side surface of a resin-molded package, wherein a heat sink fin mounting plate is formed in unitary structure with a plate for carrying a semiconductor pellet and arranged to project from a recessed portion of the opposite side surface of the resin-molded package and a heat sink fin has one end bent in U-shape and caulked on the fin mounting plate and the remaining portion overlapping one principal surface of the resin-molded package. The projection of the heat sink fin from the resin-molded package can be reduced to enable the device to be assembled in compact electronic instruments or devices. Heat dissipation efficiency can also be improved by mounting the semiconductor device on a chassis with the heat sink fin brought in contact with the chassis.