Patent ID: 8741695

Claim:
A method of manufacturing a semiconductor device, comprising the steps of: (a) preparing a substrate including a metal base plate, an insulating sheet disposed on said metal base plate, and a wiring pattern disposed on said insulating sheet; (b) mounting semiconductor elements on said substrate; (c) forming a molding resin covering said semiconductor elements on said substrate, including: (c-1) disposing a plate-like member of a thermoplastic resin to be opposed to a surface of said substrate on which said semiconductor elements are mounted, the plate-like member including at least one opening through which an external terminal communications part is exposed; and (c-2) filling said molding resin between said substrate and said plate-like member; and (d) after said step (c), cutting said molding resin and said substrate to cut out a plurality of semiconductor devices on which said semiconductor element is mounted, wherein a trench is pre-formed in said substrate so as to extend along a cutting line in said step (d), said trench having a width larger than a width of said cutting line and passing through said wiring pattern and said insulating sheet into said metal base plate, and in said step (c), said molding resin is filled inside said trench.