Spot plated leadframe and IC bond pad via array design for copper wire
View Patent ↗There is provided a system and method for a spot plated leadframe and an IC bond pad via array design for copper wire. There is provided a semiconductor package comprising a leadframe having a pre-plated finish and a spot plating on said pre-plated finish, a semiconductor die including a bond pad on a top surface thereof, and a copper wire bonded to said spot plating and to said bond pad. Optionally, a novel corner via array design may be provided under the bond pad for improved package performance while maintaining the integrity of the copper wire bond. The semiconductor package may provide several advantages including high MSL ratings, simplified assembly cycles, avoidance of tin whisker issues, and low cost compared to conventional packages using gold wire bonds.
1. A semiconductor package comprising:
a leadframe having a pre-plated finish and a spot plating on said pre-plated finish;
a semiconductor die including a bond pad on a top surface thereof; and
a copper wire bonded to said spot plating and to said bond pad, wherein a plurality of vias are arranged in a corner array pattern under said bond pad such that a central area under a portion of said bond pad for receiving said copper wire has a low density of vias, and remaining perimeter and non-perimeter areas under said bond pad have a high density of vias.
2. The semiconductor package of claim 1 , wherein said pre-plated finish is a Ni/Pd/Au finish.
3. The semiconductor package of claim 1 , wherein said spot plating comprises silver.
4. The semiconductor package of claim 1 , wherein said leadframe comprises copper.
5. The semiconductor package of claim 1 , wherein gold wire bonds are not present.
6. The semiconductor package of claim 1 , wherein said semiconductor package achieves a moisture sensitivity level (MSL) rating of MSL 1.
7. The semiconductor package of claim 1 , wherein said leadframe does not include a tin plating.
8. The semiconductor package of claim 1 , wherein said semiconductor die and said spot plating are situated on said pre-plated finish on said leadframe, and
wherein the leadframe further comprises a die paddle portion, and a second spot plating, wherein said second spot plating is situated on a pre-plated finish of said die paddle portion.
9. The semiconductor package of claim 8 , wherein another copper wire is bonded to said semiconductor die and to said second spot plating.