Patent ID: 8048718

Claim:
A method for manufacturing a semiconductor device comprising the steps of: providing a semiconductor device comprising a resin body encapsulating a semiconductor chip therein, a first and second leads extended outwardly from said resin body, a dam bar connected between said first and second leads, and an excess resin portion protruding from said resin body between said first and second leads and said dam bar; and cutting connection portions between said first lead and said dam bar and between said second lead and said dam bar by a punch, wherein said punch has a first cutting edge and two of second cutting edges, said two of second cutting edges are arranged in parallel to each other, said first cutting edge is sandwiched between said two of second cutting edges, said first cutting edge has first and second convex portions and a concave portion, said concave portion is sandwiched between said first and second convex portions, and wherein in said cutting step, said punch is positioned in such a way that said two of second cutting edges are located at said dam bar so as to face to said first and second leads, respectively, each tip portion of said first and second convex portions is located at said excess resin portion, and a mid portion of said concave portion is located at said dam bar, then punch a part of said excess resin portion and a part of said dam bar with said punch.