Leadframe for semiconductor packages

摘要

A leadframe for semiconductor packages is provided. The leadframe includes a die pad, a side rail, a tie bar, and a plurality of leads. The side rail is around the die pad. The tie bar connects the die pad and the side rail. The leads extend from the side rail to close proximity to the die pad. The leads includes a first lead and a second lead being at opposite locations of the leadframe relative to a center line through the die pad. The first and second leads are substantially asymmetrical with each other relative to the center line and have different impedance values. The plurality of leads are disconnected from each other.

主权项

1. A leadframe for semiconductor packages, comprising:
a die pad; a side rail around the die pad; a tie bar connecting the die pad and the side rail; and a plurality of leads extending from the side rail in close proximity to the die pad, comprising a first lead with no branch and a second lead being at opposite locations of the leadframe relative to a center line through the die pad, wherein the first and second leads are substantially asymmetrical with each other relative to the center line and have different impedance values, wherein the plurality of leads are spaced apart from each other, and the plurality of leads further comprise a third lead adjacent to the first lead, and fourth lead adjacent to the second lead, wherein the plurality of leads are directly and electrically connected to a chip attached on the die pad through a plurality of bonding wires, and each of the first and second leads is connected to a different one of the plurality of bonding wires, wherein a pitch between the first and third leads is different from a pitch between the second and fourth leads.