Semiconductor device

A lead frame made by the following process comprising, the steps of etching with a first etchant, a three layer metal structure wherein first and second outer metal layers are made of a material which is etched by said first etchant and a third intermediate metal layer is not etched by said first etchant so as to form a relatively thick outer lead from said first outer metal layer which extends in a first direction and so as to form a relatively thin inner lead from said second outer metal layer which overlaps said first outer metal layer and extends in a direction opposite to said first direction, and etching said third intermediate metal layer with a second etchant to form an electrical path area between said first and second outer metal layers in an overlap area and to also form a bump on said second outer layer which is remote from said overlap area, and, wherein said bump has a width ranging from 10 to 140 .mu.m.

A lead frame made by the following process comprising, the steps of etching with a first etchant, a three layer metal structure wherein first and second outer metal layers are made of a material which is etched by said first etchant and a third intermediate metal layer is not etched by said first etchant so as to form a relatively thick outer lead from said first outer metal layer which extends in a first direction and so as to form a relatively thin inner lead from said second outer metal layer which overlaps said first outer metal layer and extends in a direction opposite to said first direction, and etching said third intermediate metal layer with a second etchant to form an electrical path area between said first and second outer metal layers in an overlap area and to also form a bump on said second outer layer which is remote from said overlap area, and wherein said outer lead has a thickness of 30 to 300 .mu.m, and wherein said inner lead has a thickness of 10 to 50 .mu.m, and wherein said electrical path area and said bump have thickness of 5 to 50 .mu.m.

A lead frame made by the following process comprising, the steps of etching with a first etchant, a three layer metal structure wherein first and second outer metal layers are made of a material which is etched by said first etchant and a third intermediate metal layer such as aluminum which is not etched by said first etchant so as to form a relatively thick outer lead from said first outer metal layer which extends in a first direction and so as to form a relatively thin inner lead from said second outer metal layer which overlaps said first outer metal layer and extends in a direction opposite to said first direction, and etching said third intermediate metal layer with a second etchant which does not etch said first and second outer metal layers to form an electrical path area between said first and second outer metal layers in an overlap area and to also form a bump on said second outer metal layer which is remote from said overlap area.