Abstract: In construction of a plastic molded semiconductor package provided with a heat sink and electrically conductive leads attached to the periphery of the heat sink, a conventional electrically insulating, adhesive bonding tape is replaced by a non-adhesive insulating sheet and support bars are locally provided in a lead frame between the leads. For uniting the leads to the heat sink, the support bars are fixed to the heat sink whilst sandwiching the insulating sheet. Elimination of the adhesive bonding tape greatly reduces intrusion of contaminants into the package, simplifies the production process and lowers the production cost.

Abstract: In construction of a plastic molded semiconductor package provided with a heat sink and electrically conductive leads attached to the periphery of the heat sink, a conventional electrically insulating, adhesive bonding tape is replaced by a non-adhesive insulating sheet and support bars are locally provided in a lead frame between the leads. For uniting the leads to the heat sink, the support bars are fixed to the heat sink whilst sandwiching the insulating sheet. No use of the adhesive bonding tape greatly reduces intrusion of contaminants into the package, simplifies the production process and lowers the production cost.

Abstract: In construction of a plastic molded semiconductor package incorporating a metallic heat sink, the heat sink is made of a thin plate but provided with a central die support depressed from the plane of a surrounding lead support, the section opposite the die support being exposed outside a plastic package. Use of a thin plate as the material enables efficient, continuous processing in production. Presence of the depressed die support assures elongated boundary between the heat sink and the plastic package, thereby effectively reducing undesirable invasion of outer contaminant.