Abstract: The present invention provides a resin-encapsulated semiconductor device having inner leads and at least a heat spreader, wherein at least an electrical insulator is provided between the inner leads and the heat spreader, or wherein suspension pins for suspending an island mounting a semiconductor device are formed to have a lower level than the inner leads, or wherein the heat spreader has a fixing means for fixing the heat spreader over position, or wherein the heat spreader has an elevated center region having a light level than a peripheral region of the heat spreader.

Abstract: There is provided a mold die set for molding a package body which is composed of a lead frame and a semiconductor chip mounted on the lead frame, and the lead frame has a hole. The mold die set is composed of an upper mold die and a lower mold die and the package body being clamped by the upper mold die and the lower mold die. The lower mold die includes a runner section, a table section connected to the runner section and protruding from a bottom of the runner section, a lower concave section connected to the table section, and a lower gate disposed between the table section and the lower concave section.

Abstract: A molding die for sealing a semiconductor element with a resin includes an upper and a lower mold half. A leadframe having a resin passage aperture is sandwiched between the lower mold half and the upper mold half. The lower mold half has a lower runner space, a lower cavity, and a lower gate provided between the lower runner space and the lower cavity. The upper mold half has an upper resin well, an upper cavity, and an upper gate provided between the resin well and the upper cavity. The length of the upper resin well in the direction of the flow of resin is equal to or greater than the distance from the lower gate to the front edge of a lower runner rising slope, to thereby obtain a final product which is free from resin burrs formed in the upper resin well.